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The Morkrum system of printing telegraphy

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

A THESIS

PRESENTED BY

RALPH H. EARLE AWOL she PRESIDENT AND FACULTY

OF ARMOUR INSTITUTE OF TECHNOLOGY FOR THE DEGREE OF

BACHELOR OF SCIENCE

IN

ELECTRICAL ENGINEERING

MAY SY, S17

ie Tne

e aa of Ce etri LA AAAL Engineering,

ILLINOIS INSTITUTE OF TECHNOLOGY

Dean of Engineering Studies

PAUL V. GALVIN LIBRARY 35 WEST 33RD STREET ae CHICAGO, IL 60616 is RP Ci Ong Wicgieg saa

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

OBJECT,

The object of this thesis is the composition of a detailed descrip- tion of the Morkrum System of Printing Te- legraphy.

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

FOREWORD.

The material for this thesis was obtained from the Morkrum Company, al- though the wording and arrangement is orig- inal with the writer. A number of the draw- ings of this thesis were also obtsined from

that company.

R.H.E.

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

Table of Contents

Part I - Introductory GENERAL - = = = = = = PRELIMINARY SYSTMM - - - - SECOND SYSTEM - = = = «= THIRD SYSTEM - - = = = = FOURTH SYSTEM - = - = = FIFTH SYSTEM - - = = = = SIXTH SYSTEM - - - = = «=

Part II - THE TAPE = = = = = © «= THE CODE - -© = = = = = THE PERFORATOR - © - = = GENERAL LAYOUT - - - = = THE PUNCH PINS - - = = = THR HAMMER - - - = = = THE PUNCH LEVERS - = - = SELECTIVE MECHANISM - = - TAPE FEED - - = = - = =

p.3 pe? p.8 p.ll pe2l pe25s pee?

Perforator p35 p.37 p.39 p42 p42 p47 p.49 p.50 p.56

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ae we we Se wy ee ep a oe ta aD et ke i er =~ = = « s s §ORAROTIET Tat ~ - = = «= = QUOYAL CATHWRS - + « = « = @NI¢ HONGT BHF

- = = = «© = = SEMMAR DHT

- = = = © @SHVEI HOWUL FET

- = «= = M@IWAROSM BVITORIAG we wee ee ee ae

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd)

BAM OPUARR RO ea oe ok ee END-OF-THE-LINE INDICATOR - - - p.60

Part III - The Distribution System

GENERAL - - - - - = = - = p.68 MOTOR - - - - - = = = = = p.69 TAPE CONTACTS - - - - = - = p.71 TAPE FEED - - - = - - - = p.73 WOANGULGSION). 4 =. 4 je = =. = p.78 AUTOMATIC STOP - = = - = = = pe79 CUT-OUT - - =- = = = = = = p.85 TRANSMITTING DISK - - = = = = p.87 POLE CHANGER RELAYS - - - - = p.90 RECEIVER DISK «© - - = = = = p.92 TRANSMISSION SHAFT = - - - = = p.93 SYNCHRONIZER - - - - = = = = pe94

DISTRIBUTOR CIRCUITS - = - = = pyl04

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd)

MOTOR CIRCUIT - - - = = = = = p.104 TRANSMITTER DISK CIRCUITS =~ = - = p.105 AUTOMATIC STOP CIRCUITS = - = - p.110 RECEIVER CIRCUITS = = = = = = p.1il POLAR DUPLEX OPERATION - - - - - p.114 WHEATSTONE DIFFERENTIAL RELAY - - =- p.122

Part IV - The Printer

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STRIKER LINKS - - - = - = = = pel5S

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd)

SHrye RS AO CLRCI TL - oo 266 SHIN WOT TONS + we ee hy SELECTOR MECHANISM - - - = = -p.159 SELECTOR DISKS =< = = = = = - 'p.161 SELECTOR DRUM - = - - - - - - .167 WOtdeds BOGE S 4. -.- et DO SPACER AND BACKER - - - - - p.173 PLATEN AND LINER - - - - - = p.185 PRINTER CIRCUITS - - - - = = p.190 ACTUAL SELECTOR CIRCUITS - - - p.193 LOCK RELAY CIRCUITS - - - - - p.194 LOCK AND PLATE RELAY CIRCUITS - - p.19” FINAL SELECTOR CIRCUITS - - - - p.200 INSTRUMENTS - - - - - = = p.209 OPERATING CIRCUITS - - - - - p.212 ROTATOR CIRCUITS - - - = - - p.2l14 CENTER LETTER CIRCUIT - - - - p.216

SPACER AND STRIKER CIRCUIT - - - p.217

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WIS.q - = - TIUORIO AEXIATA CMA AMOATE

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Table of Contents (Cont'd)

PRINTER DISTRIBUTION CIRCUIT - - p.2z0 OPERATING CIRCUITS - - - - = pe223 MAIN BREAK CONTROL - - - = = p22 SPACING CIRCUIT - = = = = = pe225 BACKING CIRCUIT - - - -- - - p.227 SHIFT CIRCUITS - - = = = = = p.228 RUB-OUT CIRCUIT - - - = = = p.231

DISTRIBUTION CIRCUIT - = = = = p.232

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Illustrations

Introduction Figs. 1 - 6 Impulse Diagram Code, Tape, and Perforator Figs. 7 - 15 Plates 1 - 2 Distribution System Figs. 16 = 30 Plates III - Viii Printer Figs. 30 -64 Plates IX - XII.

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Part I - Introductory.

GENERAL, In the operation of the Morkrum System of Printing Telegraphy, the message to be transmitted is first transcribed onto a perforated paper tape according to a eode of perforations. This operation is perform- ed on a keyboard perferator, just as though the message were being typewritten. The tape is then run through an automatic transmitter. This device, termed the transmitting distributor, sends out a series of electrical impulses over the line; the character of these impulses is determined by the perforstions in the tape.

At the receiving station, the line impulses enter an automatic receiver, call- ed the receiving distributor. Through the agen- ey of this distributor, the incoming impulses control a series of receiving relays, which re- lays, in turn, control the action of a print-

ing device. This printer is an automatic type-

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

writer which prints, or typewrites, the message onto a standard message blank.

Printing telegraph systems in general possess distinct advantages over Morse systems, especially on heavy traffic lines. Printing telegraphs do not demand the services of skilled operators, whereas Morse systems are entirely dependent upon such services. This circumstance is becoming more and more impor- tant by reason of the growing scarcity of Morse operators and the consequent increase in wages demanded by them. Furthermore, the printing telegraph is able to maintain for the entire day, a speed of transmission somewhat greater then the maximum speed obtainable by manual operation. Consequently, fuller service from the equipment as well as a decrease in operat-

ing costs is gained when a printing system is

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

substituted for Morse.

Béfore taking up a detailed study of the Morkrum System of Printing Teleg- raphy, we must establish the principle upon which the line signals are transmitted. This operation is performed by the machines before referred to as distributors. In order that their operation may be clearly understood, a simple device will be chosen which possesses certain features in common with the distribu- tors. This device will gradually be developed until it finally embodies the main features of the actual distributing apparatus. After this preliminary treatment, we can take up a study of the Morkrum System in its practical form.

PRELIMINARY SYSTEM, Certain of the underlying principles of the Morkrum System of Printing Telegraphy are embodied

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

in the telegraphic scheme of Fig. 1. D and D' are two stationary wooden disks or bases, fit- ted with bearings at their centers. A shaft,

S, runs in these bearings, and at each end of the shaft is mounted a metal brush arm, A. These brush arms are in the same angular po- sitions with respect to the shaft; in other words, they are in line. At its outer end,

each arm carries a brush, which trails or wipes over its disk when the shaft is revolved. On each disk, and in the path of the brush, is located a series of five contact buttons, thesé contacts being similarly placed on each disk. Since the spacing of the arms and contacts on each disk are the same, the two brushes will always make contact with corresponding buttons. For example, if the brush at the left rests

on the top contact, 1, the brush on the right will rest on the top contact, 1, at that end of

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the shaft.

As for the électrical arrange- ment, at the transmitting station the contact buttons,l, 2, 3, 4, and 5, are connected re- spectively to the keys, Ki, Kp, Kg, Ka, and Ks, thence through the battery, B, to ground at G. Therefore, when a key is depressed, the corresponding button will be connected to the battery. At the receiving station, each of the buttons is connected through its own re- lay to ground at G',

The operation of the apparatus is as follows: Rotate the shaft, S, by some means in the direction indicated by the arrow. The brushes will then wipe over the buttons in the order 2.25.5. 4. 5.3. 2. ---, Mere. fore, if key K, be depressed, the negative Side of the battery will be connected to but-

ton 1, and while the transmittimg brush is

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

passing over the button, a circuit will be completed through the shaft, S, contact but- ton 1 on the receiver disk, through the re- lay Rj, to ground at G', and thence to bat- tery, B. The resultant current will operate relay Ry. Likewise, if any other key or com- bination of keys be depressed, the corres- ponding relays will be operated at the receiv- ing end,

One method of carrying on com- munication with this device would be to arrange & code, assigning a combination of key-depres- sions (or relay movements) to each desired character or letter of the alphabet. In all, thirty-one combinations might thus be obtained. One complete combination or letter would be sent out for each revolution of the shaft,

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revolution, we could send out the successive

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

letters of a word or message, and an observer at the receiving end could read off the mes- sage by the relay movements.

The system just deseribed is of course impractical because it is necessary to connect the two stations by the shaft, S. Fig.2, however, illustrates a plan without this defect.

SECOND SYSTEM, In this second scheme, the two brush arms are not on the same shaft, but are rotated in unison by separate driving mechanisms not shown in Fig. 2. The electrical connection between the two points is maintained by the wire marked "Line", which may be an ordinary telegraph line. Hence, we may have the transmission of signals over @ considerable distance.

Messages are transmitted in

this scheme in exactly the same manner as in

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the first case. The two driving mechanisms and the means for keeping the two arms in step of course introduce new features, but it is not necessary to discuss these features

at this point.

A great improvement in the scheme of Fig. 2 would be effected if some other means of transmission were used instead of the five keys; these keys are too slow and cumbersome. Consequently, an automatic trans- mitter has been devised and applied to the system; the new system appears in Fig. 3.

THIRD SYSTEM. In the scheme of Fig. 3, the contacts and vertical contact pins, 1, 2, 3, 4, and 5, have been substituted for the corresponding keys of Fig. 2. These pins are mounted loosely, near their ends, on & common horizontal shaft or fulcrum, and have

& lever action, through a small range, about

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emedoe edt aI .MiTcYe CHInT

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trodes ,ogmex flame 2 dgvotdd ,coltos tevel 8

“ae Latte 2 we x Dl ar

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

this shaft. The contact is made at one end of the lever, so that a slight movement of the other end makes or breaks the contact.

The movement of the levers, with the consequent opening and closing of the contacts, is effected by means of a perforated paper tape. This tape is pulled along flatways under the free ends of the pins. At intervals, holes are punched in the tape, and when one of these holes comes under a pin, the end of the pin drops through the hole. This movement of the pin or lever closes the contact; this con- dition corresponds to a closed key in Fig. 2. The tape must move along at such a speed, that the combinations of contacts, corresponding to the individual letters, are maintained throughout a complete revolution of the brush arm. That is, there is always a definite rela-

tion between the speed of the tape and the speed

0

YHTAAOGINT PAITUIAT TO MATEY MURAHOM FHT

to bas eno ss obam ef tostmoo efT . Stade efdt edt to tromovom tdatfe es tedt o@ .tevel ent etoatnoo oft exsetd to eouvlsm bas tedto

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10

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

of the brush arm. If the tape is punched proper- ly, line impulses corresponding to a message can be sent out.

Furthermore, the rate of trans- mission can be increased over the rate of the old system by the operator raising the speed of the tape, and at the same time raising the speed of the brusharms in the proper proportion. By these means, any transmission speed is obtain- able, ranging from zero to seventy-five or more words per minute.

However, the rapid transmission made possible by the tape control introduces a new and serious problem, viz., the distortion of the line impulse. This distortion is carried to such an extent that inaccurate receiving is the result. This matter of distortion can be better understood, and a solution devised, through @ study of a aoukca of current impulses; we

will, therefore, now take up such a study.

OL

YHIAAOMICT QOULTUIAT TO MATeYe MUAHHOM GET

-tegotq fedoung ef eqet odt tI .mre devrd edt to nso egsasem s of ai Fiieuhetres sestnemt emit eet | otro dace od

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-Ybute 2 dove qe oxst wor iecitionane yet

| ae pe

ree ment eae

aba I

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

CURRENT IMPULSES. A series of ideal current impulses is represented in dia- gram (a). Such impulses occur only under perfect operating conditions. This particular series would be sent out by the transmitter during one revolution of the brush arm, with pins 1, 2, 4, and 5; in the closed contact position, and contact 3 open.

In an analysis of the diagran, assume a certain instant, 0, from which to measure time. After a fraction of a second, represent- ed by the length Ot j, the transmitter brush strikes button No. 1; since pin contact 1 is connected to the battery and is closed, the button is connected to the battery. Immediately, the line current rises to its full value, Ij, shown as the distance OIj, and it maintains this value throughout the duration of contact.

At the instant te, the transmitter brush leaves

[£

YHTAHORIAT DULITMIAZG TO MATeYe MUAAAOM THT

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Bn tne

12

THE MORERUM SYSTEM OF PRINTING TELEGRAPHY

the button, and the current immediately falls to zero. This time of contact, represented by tit2, is called a marking interval, and during this entire time, an impulse is being sent out over the line.

As for the succeeding periods, te-tz indicates the time necessary for the brush to go from one button to the next. The space t3-t4 stands for the time of brush passage o- ver the second button; it is a marking or pulse interval, since the second pin contact is as- sumed to be closed and its contact button ener- gized. Next, ta-t5 is the intermediate space between the second and third contact buttons.

The next interval, however, is different from any of the preceding ones. Dur- ing this time, t5-ts, the brush is passing over the third button. It will be remembered that the third pin contact was assumed to be open;

hence, the third button is not connected to

YHIAADELAT PUITHIAT TO METeYe MUSANAOM FHT

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ot betoennoo tom et sotdud Sridd edt .eorted

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the battery; therefore, no current or line impulse appears during this interval. This is known as a spacing interval, as opposed to mrking interval.

Following this period are the two marking intervals as shown, properly spaced and in every way similar to the first two marking intervals.

A series of impulses such as these is desirable in every respect. The marking and spacing intervals are regular and sharply defined; the current always as- sumes the same value for each pulse.A proper- ly constructed receiver should respond per- fectly to such signals.

However, it is not practical nor even possible to produce such impulses under actual operating conditions. Instead, the series takes the shape indicated in (b). Here, the sharply defined impulses of (a)

become wavey, with rounded corners and no

13

éL

YHIAADEINT OUITMIAT FO METSY2 MUSNAOM SHT

enti ro deerme on ,stoteredd iyretisd edt etd? .Isvretat efdt antush exseaqqe seloqmt hesogyo as ,favretat gatesya s a8 mwond et wfsvretat gurivtem ot

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esaluqat dose essbony of efdtaeor move ton

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om bua eredtoo bebavot dtiw .veven ont i

Ku

14

THE MORKRUM SYSTEM OF PRINTING. TELEGRAPHY

definite line between succeeding pulses. The middle or spacing interval is bridged over so that it appears as a weak marking pulse. Or, the pulses may be still further distorted and assume the form of those shown in (c); this latter, in fact, more nearly represents the true form of the working pulses.

As for the causes of this dis- tortion of the impulses, there are two prin- cipal ones. The change from the regular im- pulses shown in (a) to the wavey form shown in (b) is caused by the phenomenom known as cur- rent lag. In brief, due to the inductance of the telegraph circuit, the line current does not rise to its full value the instant the cir- euit is closed by the brush arm contact. In- stead, it rises gradually, requiring a very ap- preciable time to reach its full value. This time of rise for the first impulse is shown as

ti-te in (b). In the same way, the current does

i

YHIAASDAINT OMITHIAT FO MATeYe MURUHOM ART

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as mwota ef selaqat tertt edd tot eatt to omit

aeob theriro edd ,yew omee edt mI .(d) at gt-ct

=p Soh)

HOE Ree

15

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

not fall to zero the instant the transmit- ting brush leaves a contact button, but, on account of the capacity of the line, requires an appreciable time to do so. This time of fall is shown as t3-t4 in (b). Thus, the cur- rent does not obey the makes and breaks of the circuit immedietely, but is said to lag. When the impulses follow each other rapidly, one does not die away before another begins. The result is that the impulses run together; two marking intervals, separated by a spac- ing interval, often do this, thereby obli- terating the spacing interval.

The saw-tooxth form of the wave, as shown in (ce), is caused by induc- tion. The neighboring telegrapg wires induce small varying currents in the line, so that the resulting current, made up of the induc- ed and working currents, is of the irregular

form shown, The induced currents have the

af

YHZARORIAT QUITUIAI TO MATeYe MUSAAOM FHT

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

greatest effect during the early growth of the impulse; they may even be large enough to reverse the direction of the line cur-

rent while the impulse is till very smell. When the impulse has grown to a reasonable size, the induced currents are absorbed.

A consideration of the caus- es of distortion will shown that since cur- rent lag and induction increase nearly di- rectly with an increase in length of line, the amount of distortion varies nearly di- rectly with the length of line.

The effect of impulse dis- tortion on accurate receiving of signals is apparent. Not only does confusion result from the bridging over of the spacing inter- vals, but also from the fact that the re- ceiver lags behind the transmitter. This lag occurs because the receiver does not respond

until the impulse has grown to a working

16

af

YHQARDAIRT OMITUIAT TO MaTeYe MUAAHOM HHT

to dtworg ylrse edt snttyb sootts testsers dayone earsl ed mevs yem yedt ;saluqmt edt -tw5 omit eft to mottoertth edt eetever ot -{fems vrev [fit et saluqmt edt olfidw taet efdanogeset s ot mworg aad safuqmt eft cmet¥ -bedtroeds eta sinerrss boeorbal edd ,ssia

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guiidtow s ot aswors asd eeluqmt edt [tian

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

value. The induced currents do not, as a rule, reach sufficient magnitude to oper- ate the receiving relays; their usual ef- fect is to distort the impulse by destroy- ing the early part, and thereby still fur- ther retard the receiver. Since the amount of distortion depends upon the length of

line, the longer the line is, the more dif-

ficult becomes operation; satisfactory opera-

tion cannot be maintained over lines of any practical length.

With the underlying causes of distortion in mind, we are now prepared to take up the solution of the problem. A study of the impulse diagram will show that the question becomes one of causing the im- pulses to grow to their final working value very rapidly. If the impulses should rise quickly, they would not tend to spread out

aT

¥I

YHTAROAIAT QUITUIAT GO MaTeYe MUAAHOM FHT

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18

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

so much, so that there would be a sharp di- viding line between marking and spacing in- tervals. Furthermore, the effect of the in- duced currents would be minimized, since their greatest effect occurs during the ear- ly growth of the pulse, which period would be short.

The solution which has given the most satisfaction is what is known as double current operation. In this scheme, there is a marking pulse as before. However, instead of a space interval being indicated by a current pulse of no magnitude, that is, by an absence of current, it is indicated by a current pulse in the opposite direction. For convenience, the spacing pulse is called positive, whereas the marking pulse is called negative. The terms positive and negative

merely indicate that the line currents are

BL

YHLAASALIAT PULTHIAL TO METCYS MUAMHOM SHT

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

opposite directions in the two cases. The use of both marking and spacing impulses of course necessitates some changes in the equipment, but these changes will be taken up a little later.

The reason for the more sat \kisfactory operation of the double current eatin ean be more clearly understood after that explanation of certain principles of current rise in a circuit. It was just shown how, when there is current in a circuit, the current legs or falls to zero gradually when the circuit is opened. If an e.m.f. be ap- plied, opposite in direction to the one which established the current, the current will fall much quicker than it otherwise would. If the e.m.f. be maintained, the current will decrease, pass through zero, and build up in

the other direction.

19

ef

YHIAADATIRT QUITHIAL TO METeYe MUSAHOM THT

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eit mt aegaedo emoe eetstissesen eerson to

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wtetel efttil se gi

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[Ltw trove od¢ teers eft Bedelfdatee |

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| ,mottesrib redto edt

-'y a ee ee Se

20

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

to illustrate the application of this prin- ciple to our own problem, consider the same impulse series as was used in the previous discussion, except with both mrking and spac- ing pulses. The intervals of this series are marking, marking, spacing, marking, marking, or, in terms of current direction, negative, negative, positive, negative, negative. This series is pictured in (da).

‘An observation of diagram (4a) shows that the two negative or marking pulses which come first are the same as in diagram (ec). But at the beginning of the third or spacing interval, a positive e.m.f. is applied, which action causes the line current to fall almost instantly to zero and start to rise in the positive direction. Likewise, st the be- ginning of the fourth interval, which is mark- ing, the line current quickly reverses and

builds up in the negative direction. The last

YATAADAIRT OQUITUIAL TO MATEY MUAAHOM FHT

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teel edT .gwottostibh evitsagens edt at qn ebfinud

21

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

two intervals are marking, similar to the first two.

A further observation of the diagram shows that the marking and spacing pulses are clearly defined. Furthermore, the pulses are at high values throughout nearly all of their existance, so that the induced currents from other lines are soon absorbed. Thus, the problem of producing definite pulses, little affected by induced currents, is ap- parently solved.

FOURTH SYSTEM. The applica- tion of the principle of double current oper- ation to the telegraphic system which was de- veloped earlier in this discussion appears in Fig. 4. However, before the system as a whole is explained, two new pieces of apparatus should be described.

The first of the new devices

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eookveb wen “ott 0 text oat

22

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

is a relay pole chenger. This is an ordinary Felay.equipped with both front and back con- tacts. When the relay coil is not energized, the armature remains against the back contact, but when the coil is energized, the armature is drawn forward against the front contact. The other new device is a polarized relay. This relay has an armature which plays between two contacts, but has no retractile spring. When the coils of the re- lay carry current in one direction, the ar- mature takes position against one contact. If the coil current is reversed, the armature goes over to the other contact. Since there is no retractile spring, when there is no current in the coils, the armature remains against whichever contact it happens to be. With this understanding of

these new instruments, we can take up an ex-

Ss

YEIAROAIAT OQUITMIAL 20 MeTeye MUSAHOM FHT

yrsenibro mea ef aftdl .teansdo efog yeler a at -~aoo dosd bas sgaort dtod dttw beqdtups, ysiet Sesisrene tom et [foo ysfer oft medW¥ .etost eTostaon Moad edt tenters eantamet ovetamre oft ersteants. oft ,.besigrtone et ftos eft sodw tod ,toataoo txort edt taniess brawrot ovatd et s ef sotveb wen teito ext evutemrs me eat yelor eifT .yaelort besirelog on sad sud ,etsstaos owt neowted eyslq doidw ~9t edt to eftoo edt aefY .anitrqe olitosrtet -rs edt ,mottosrt5 eno mt tieriso yriso ysl tI .toetnos eno tantegs coftteog eevest eryteam ermteacre eft ,berrevet ef tasiis9 [too ait otedt esatt .testmos sedto eft ot tavo ae0g on ef etent sorw ,gnizrqe eLitosrter om at eniamet ettanre edd ,altoe eft at trerise od ot snogqad tt testnoo revetotdiw tentays

f

to gatineterobang eidd Atty

~-xe fs qy eist mso ow ,eineswittant wen evedt -

BD gd a (Lg

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

planation of the new scheme, As in the pre- ceeding system, there are the tape contacts. These contacts do not, in this case, control the line impulses directly, but do so through five of the relay pole changers just describ- ed, one pole changer being provided for each of the five tape contacts. Each set of relay coils is connected to the local battery by means of its own tape contact, so that when the contact is open, the relay is not ener- gized and the arm ture remains against the back point; when the tape contact is closed, the relay is energized so that the armture

is drawn over to the front point. The current path from the back point of the relay pole changer is to the negative side of the mrk- ing battery and through the battery to ground. The front contact is connected to the positive side of the spacing battery, the negative side

23

és

YHIALOLITT HPUITHIAI TO METeYe MUSMAOM HT

-erq edd at eA .emonoe wer eft to notiansi¢ .eteostaos oqat oft ets etedt ,meteye anthes fortmeoos ,saso etht at ,tom ob etostmnoo seodT _figsorlt of ob ted ,.yftoertS seeInqmt oentl edt -diroeeh tant etesmsdo efoq yelet edt te ovit dése tet bebtvorg ented texzmedo efog sro ,be yelet to tee dos® .etoaetmon eqet evit edt to yd yrottead Isool edt ot Hotoonnoo ef elroo nodw tsdd og ,tostnoo eqst mwo efi *o ensom «teme tom ef yvafer ef? ,.mego ef toatnoo eit ext tentage ertemer eroterrs oft bee bests ebesols eat sostmoo erat oft todw ,tatog aoad emtenre oft tedt oe bestarene et yslet edt tasrtys of? .tetog taort edd ot revo mwerh et eLoqg yalet eit to tatog xoad oft mort Atsq -tzam eft to obta evitagea edt ot ef teanado Aavors of yrettad ont davordt Bas profiad gat evittnog edt ot Betooktroe et toatmoo tnort ed? ebte evisazen edt ,yrotted grteaqe edt to ebte

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

of which goes to ground. The armature is con- nected to one contact button of the transmit- ting disk. The revolving brush arm is connect- ed to the line.

A consideration of the trans- mitter circuit shows that with a tape contact open, @ negative or marking line impulse is sent out, and with a tape contact closed, a positive or spacing impulse is sent out. Thus, the tape contacts control the character of the line impulses.

At the receiving station, the line is connected through the operating coils of a polarized relay to ground. Therefore, a positive current pulse throws the armature to one side or point, whereas a negative pulse throws the armature to the other point. One point is dead, the other point is connected

to one side of the local battery, and the ar-

24

.RAE on ee Sey eee De | Tomer

SS

YHIAROAIGT OUITMIRI TO MATAYe MUAAHOM RAT

-f09 eft erstemrs 6X? .foayora oF goog dotdw to -timenett odt to nottud tostmos. emo ot hotsoen -toentos et ore devid entvfover edt .welb satt ~oait oft ot bo -ecstt ot to cotiarsbienos A tostiros eqat es ditiw tent ewore tinotto tett ta ef eeluqmt satl antvren to evitenen s ,asdo s ,boeofo tostros saat s dtiw ins , tro tree end? .dso tase af eafmamt sxtésqe to ovitteog to totosrads odd L[ortmoo atostado sqst edt -boaluqmk exrfl edt eft ,acottate satvieser eft tA aftoo gattsteqo edt dasotdt hetoonnos et enlkl ‘8 ,9toteted? .bavors ot esler BSositefog s to ot erstemrs eft ewortt saluq tnevttyo svitteog seflouq evitsgen es agsetedw ,tatog xo shite emo em0 .tatog teddo edt ot srutemrs oft ewordt hetsonroo at tatog tedto edd ,beeb et! tatog | ~-ts edt bra ,ytettad [sool edt to obta emo ot

25

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

mature is connected to the receiver brush arm. The receiver relays are connected between their respective control buttons and the free side

of? the local battery.

As for the operation of the receiving apparatus, suppose a spacing or po- sitive line impulse appears. The armature of the polarized relay goes to its dead contact, so that no local relay is affected. Suppose a negative or marking interval next appears. The armature of the polarized relay goes over to the opposite point, which is connected to the battery. The local relay is energized, and in- dicates a signal. Thus, in this system, the local receiving relays respond only to the marking intervals, just as was the case in the former system.

FIFTH SYSTEM. Fig. -5 shows a

still further development of the system. This

3s

YHCAADATET OUITMIAG TO MATSYe MUSAHOM GHP

ars desxd tevteost edt ot hSetoonmog al etutam tlad¢ meewted betooamoo ota ayslet tevieoss edT ebte sett oft bus enottad Lottaoo evitoeaaet -Yiretisd L[seol edd to edt to aottareqo edt tot eA

-“O¢ £0. uttosqe = esogare ,astarsqgs.3anivisset to eretsore edT .etseqqs salfuqmt eati evitte -tostmoo baeb att ot e903 yslet bestisloq edt ‘8 esoggue ,betoetts at yslet Leool om tedd o@ edt ,etaeqqs txen [sevietat gatizrem to ovitegen ot tevo sesog yeflot besirsiog edt to etetamta edt ot Betoonnoo et dotdw .tatog sttaoqqo edt -xt Bue ,bosigrens ef qelot Leool of? .eretted odt ,meteye sid ot ,erdT .feagte es eetsoth edt ot ylmo Dbaoqeet eyslor goiviooet [anol

edd mt ezeo edt sew es.taut ,alavretat gottrem eit smeteye temtot

8 ewore a..ght .METEYE BTWIE, oo op dey oy eka? smoteye odd to tmemgoleved tedéuut [Lite -

Reale Pipe "ete tege re 6 AA 8 ea

26

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

scheme is the same as that of Fig. 4, except that the line signals are sent out by a main- line pole changer, controlled by the relay pole changers, instead of being sent out by the relay pole changers themselves. This main line pole changer is merely a polarized relay with its operating coils connected to the bat- tery through the relay pole changer contacts, its armature connected to the line, and its two points connected respectively to the spac- ing and marking batteries. The other sides of the batteries are grounded. The operation of the system is apparent from the diagram.

This system possesses two ad- vantages over the former one. The first is that the number of contacts in the main line eirecuit is reduced to one, viz., the one at the main line polechanger. Under adverse con-

ditions of operation, this feature is of no

YHIAMOSIAT DUITUIAL TO MATeYe MUAAKOM AAT

tqooxe ,$..9f% to gedtd es emee odt et emesioe -ntea s yd two tooe ore efengte enti edt tert yelor edt vd beflertaos .,tegmads efoq omit yd tuo tase aniesd to hastack ,etrenasde efog xten efdl .eevicemedt eregmanio efog yelfst edt

yeler besitalog 2 yletom at tegaarto efog entl

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msigeib eft mort tnersqqe et moteye oendft -bg owd eeaeoacog motera etal.

eb tenit edf .eno semrol edt revo segadasy

entl nism edd at etostnos to tedmua sdit tedt

ts emo oft ..siv ,esmo ot heouber et timorte ~mfoo setevbse refhsU .teudadosfog entl atam ent

om to et etwitsst etd? ,cotteree to anoltis |

ne

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

little importance.

The other improvement appears when & number of marking or of spacing inter- vals are transmitted in succession. The main- line-pole-changer armature retains the same position throughout the series; hence, the line current is msintained constant at its full value throughout the series. Current lag therefore does not oceur except when succes- sive impulses are of different signs.

SEXTH SYSTEM. The final de- velopment of the system is shown in Fig. 6. The scheme of Fig. 6 is the same as that of Fig. 5 except for two changes in the receiv- ing apparatus. These changes still further decrease the possibilities of wrong inter- pretation of the incoming impulses by the receiving apparatus.

The first change is the fact

27

RIAU a on ¥

¥

+S

YHIASOAIAT OULITHIAL TO MITeYea MURAHOM FHT

~eomatroqmt eftrit

aveeqys tromsvorqmt refto ex? -rotait satosqe to +o satvtem to tedsaur 8s nedw -ittem efT .moteseoone at betttmeratt ore elev amsa edt entater otvtamra rsanedo-elog-ontl edy ,esonead :eetrsa edt tuodasotdt soréieoq ett ts tuatenoo heatetrtam at toerryo entl gal twermy) .eetres edt teorgcordt eslav Lint -seooua medw tqeoxe rwo90 tom Beob etotetadtt -erate dustottibh to sts eselsqmt ovte

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Gris

28

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

that the receiving polarized relay does not control the five simple relays directly, but instead, controls an exactly similar polar- ized relay, which, in turn, controls the five simple relays. This working is plain from Fig. 6.

The second change is shown sthematically: It consists of an adjustment by which the receiver disk can be moved for- ward in the direction of rotetion of the brush arm, or can be retarded against the direction of rotation of the brush arm. The total angle through which the disk may be turned is perhaps forty degrees.

The reason for this modifi- cation may best be studied from Diagram (e). This diagrem is the same as (a) as far as the wave form of the impulse is concerned.

It will be noticed from the diagrams that the

o

or.)

YHTARDALAT OMITAIRY TO MATeYe MUAMHOM AAT

tom ee0b ysfer bestrsfoq grnivieost eft tedd tod ,vftoorth ayelet efqmte evit edt L[ortmoo -telog tafimie yitosxe os efottmoo ,Ssetent evit edt afortmoo ,mivt af ,doitdw ,yelor best mort atefq at anttxow efd?..aysfor olqmte od 2 Blt awode alt eanesdo Bboooee edt

tohemtesths os to atetasoo ti ehiab hdomeche =Tot bevou ed aso welh xevieoet edt cotdw yd oft, to gottstor to mottoetlh edd at braw edy tantsss bebrster ed mae to ,mts deotd eft .mte davrd edt to mottator to mottoortb ed yam delb odd dotdw davords ofens [stot .8eetgebh ytiot aqedteq at heawt

-fithbom eldt trol noeser off | a (a) mesnelt, aoxt hetbute ed jisili tena pakie as ist a2 (5) ee omsa, eft at merasth atdT -beateonros at salngqmt odd to mot evew edt

odd tadd amatgetb edd mott beotton of Lftw tT

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

impulses are quite jagged and irregular. The irregularities may produce a slight flutter- ing of the armature of the receiving poler- ized relay, especially near the transition period between positive and negative pulses. This fluttering is not of sufficient magni- tude to throw the armature from one point to the other, but it is great enough to produce @ poor contact. Such a contact would not be desirable in the circuit of the simple re- lays.

A remedy for the uncertain contact in the circuit of the five relays is provided when the second polerized relay is added to the scheme of Fig. 5. This relay does not change its position unless the main line relay first changes; any fluctuation of the armature of the main line relay less

than a complete movement from one point to

ao

YHIAAOAIAT: DUITMIAT TO MITeYe: MUSAAOM SAT

eit .xsisgetrt bas begast stiup ers sealngmt -totiolt tigtfe e soyborq vem esititelsgetts -tsfoq anivieser edt to exsteagre edt To gat cotétenart edt rsem ylistoeqes ,yslert best -2oeling evittegon bus ovitteog neswied botreq ~ hagent dnetorttwe to toa at gitretiolt etdt: ot tetog emo mott etutenrsa oft wordt ot ebst eosborg ot agvone testa et tt tud ,zredto eft ed ton bisow tomtnoo e dowd .tostmoo to0g # -ot efqmte edt to ttvorto edt mt efdarteeh 2ayst

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the other does not affect the second relay. The armature of the second relay possesses sufficient residual magnetism so that the contact is kept firm. Hence, any flutterings of the main-line-relay armature do not af- fect the local relays.

The impulses in the local ecireuit, with the plan just described, are shown by the rectangular full-line pulses in (e). The transmitted pulses are shown dot- ted. It will be noticed that the received pulses are fair reconstructions of the trans- mitted pulses, but occur at a slightly later time because of current leg.

The second change in the sys- tem, viz., the angular adjustment of the re- eeiver disk, allows the middle, or fullest portion of the pulse to be utilized. This

fact may be understood by a reference to (e).

30

YAUAASIIAT DUITMIAL TO MTeYe MUAAAGM, EXT

-yslert baoose edt tootts tom seoh tedto seit seeeoceeg yelet Baoosa edt to otstants.edT suit tedtt of mattengsm [evbleer taotottise eativedtult yas ,eomeH smrtt tqed.ef tosiaos ~te ton of etrtanre yelor-onti-ntam odt to -aysiet.fsool edt toot [sool sndt of eselvqmt odT

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eye odt af egdedo broooe, eff ¢ -ot sdt to.tnomtartbs telwgne edd ,.atv ,mot teaelint +o ,ofhbim edt ewolls.,veth.revieo etdT ,boalliss ed ot eelsq eit. to nobdrod

-(9) ot eonsreter s yd booterehny od yam toet.

rei dak RN aly et Bet,

31

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

This diagram shows the puls- es, and also shows the buttons of the receiv- er disk developed, or rolled out, just below. The buttons are drawn in to such a scale that the diameter of each button represents the time of brush-passage over that button, and the dis- ‘iste between buttons represents the time re- quired by the brush to pass from one button to the next, The buttons are small compared to the pulses, and that portion of the pulse ly- ing directly above each button is the only portion utilized; the remainder of the pulse occurs while the brush is between buttons. By sliding the entire row of buttons along under the row of impulses, we can make any button receive any part of the impulse series.

This condition can be actually duplicated in practice by the revolution of the the disk upon which the buttons are mount-

ed. However, in practice it is never desired

VEO SN eee Nae “ aot ta ee

Lé

YHUARPRLIGT SYITMIANG TO MITSYE MUHAROM FHT

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32

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

that an impulse be received on any but its own button. Hence, the angle through which the disk turns is only sufficient as to al- low each button to receive any part of its own Lhpelee: with a little added leeway in both directions of rotation.

The results of such an ad- justment of the disk are two in number. The first is that the disk can be adjusted so as to admit only the peaks of the impulses. Hence, with the aid of the two relays on the line side of the disk, greatly distorted im- pulses can be correctly interpreted. The se- eond result is that on long lines, where the current lag may produce quite a lag of re- ceived pulses behind the transmitted pulses, the receiver disk can be rotated backward un- til the brush-and-button contact occurs at

the same time as the reception of the pulse.

St

YATASOAIAT OUITMILI LO MATeYe MUAAAOM FHT

eti gud yne mo bevitsoet 6d eelfsqmt os tadt doidw desotit efane ett ;,sorol .motiud mwo -f3 ot es toetotttue yino ef anit weth edt eti to dteq yas eviesset ot mottud dose wol ct yswoet bohbs efttil s dAtiv aetnent Fea se) nokteter to anottoorib dtodd

-ba ae dove to atiueet off edit .tedmua mt ows ors Heih ont to toomtent oa betarthe od aso death edt tedd ef terlt -goniuqmt oft to etesq edt vino timbe ot as edd mo eysiet owt ett to Ste ent dtinw ,eonel -mt hetroteth yfteerg ,deth edt to ebte enti ~e3 ed? .betetagtetat yiteerroo ed sao eselig edd eredw ,eentl smof mo tedd ef diveet bros -et to gel s etimp souborq yee asl trerivo ,eeciug bottinenert edt Satded easeinq bevies -ms hrawNoed hotsator od mao Heth revieser oft

te exrsooo toatmoo nottud-bos-deotd eft Ift

-cafeq edt to morttqeoor eft es emtt omse ont _

aie tare)

33

THE. MORKRUM SYSTEM OF PRINTING TELEGRAPHY

Another way of looking at the ¢ondition is that the two brush arms are revolving at ex- actly the same speed, but the receiving arm stays a little behind the trahsmitting arn, the distance behind depending upon the cur- rent lag.

This last described system constitutes the Morkrum System of Printing Telegraphy reduced to its simplest form. The scheme includes the essential features of the Morkrum distributors. (These are so called because they take the five character elements of position, which are found on the tape,

distribute them as impulses or elements of time, and then, at the receiving station, re- transform the elements back into those of po- sition, that is, relay positions.) This dis- tributing apparatus, together with the tape perforator and automatic printer, makes up

the commercial Morkrum System.

ES

YHTAMDETET DUITUIAZG TO METeYe MUSXAOM ANT

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THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

With this preliminary survey of the plan, we are ready to take up a de- tailed description of the commercial system. There are a number of different types, dif- fering in the minor details, but the one de- seribed in the following pages is the one commonly used on commercial duplex telegraph

lines.

34

YHTAAOSIAT OUITWIAT LO MATEYe MUSSAOM FHT

Yevive Yrenimifstq add Ati -96 8 oss exet of Theer eta ow ,melq eft to -meteve [stotemmoo edt to mottqixroveh bolfist 2%ib ,eeqyut tnerettth to tedmsmt s srs evedT -eb oso oft tud ,efieteb tontm oft at anttet eto oft et sexsq saetwolfot ont af bediroe dqetsefét xelquh fetotommos mo hoes yinomes

“P'S Seenel

” i

35

THE MORKRUM SYSTEM OF PRINTING THLEGRAPHY

Part II - Tape, Code, and Perforator.

THE TAPE. As was said before, the message to be transmitted by the Morkrum System of Printing Telegraphy is first punch- ed onto a paper tape, the number and arrange- ment of punched holes depending upon the let- ter or character which the holes represent.

Samples of the tape are shown below.

SHIFT @ E RD I SN PMR, EN Fh Le D Te ta ZR SS Fe 42

B The holes for any one letter or character are arrenged in a row across the

tape, with the proper blank or unpunched spac-

pha

Lei ber i ae a A ! Bae HA TRS ee SORA te, Ee in) ees £ ra , ems £9 0) 09 ‘ y

*

YETAAOMIAT DLITUIAT TO METAYS MUSHHOM THT

stotstotrel bas .,ebod ,eqsT - II tref

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36

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

es between holes. The rows are separated a distance of about one-tenth of an inch, this being sufficient to produce clear distinction between successive letters. Notice that the rows of holes are not exactly perpendiculer to the length of the tape, but that they Slant backward a little. The reason for this Slant will be explained in connection with the transmitting distributor.

Besides the holes used in combinations to represent letters, a con-. tinuous row of holes runs the full length of the prepared or pundhed tape. Theses holes are used in feeding the tape through the ap- paratus. The teeth of » small spur wheel en- gage the holes, so that the tape is draw a- long as the wheel revolves. This system of feeding affords a positive and definite tape

movement; the tape cannot slip without the

et ie me ee. Be

YETAROMITT PUITHIAT TO METCYS MUSAHOM SHT

s betatsqse eta ewot edt .asfor meewted eo ettit dont mae to dtnet-ero tvods to sonsterh nottontteth tsefs ssrborg ot tastofitsue anted edt tent oottol .erettel evtaassove moewiod telcotbaeqie, ¢ltosxe tom ste eoelod to ewot yedt tedt ted .scaet edd to dtamel edt of etd? rot nogser edT .oftdil s Stawfosd taale dtiw mottoenmos at bemtsfqre ed [ftw trate »votudizxters setitimenert edt mf hoes eolond edt asbiteod

.-f09 # ,erettel taoeerqar ot anoitsaidmos dtamel fist edd anor aeLorl to wor evoumit eelod esred? .eqet bedhasq to bexeqorg ext to -qe eft detromt eqat edt gctboet at beam ers -te foedw roqe [feme 2 to dteet edT -estorag -s mwarb et eqst oft tedt 08 eotod ‘edt 9389. es) motene etat seevloves. feedw eft as gaol oaat othnttes boa evitteog 8 ebrotte Batbeot fit, PRON Em aC, Sonne: eat, ot: RCE

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

feed holes being torn out. If such trouble occurs, it is at once noticed by the opera- tor and can be remedied.

THE CODE. The perforations f follow the plan of the five-unit code, which is given on the sample of tape, p.35. This is called a five-unit code because for each letter or character, there is a total of five intervals, either holes or blanks; "blank" is used for want of a better term, and denotes évery location where no hole is punched. The intervals or elements are numbered for refer- ence 1, 2, 3, 4, and 5, across the tape. The five elements allow of thirty-one combinations; hence, thirty-one characters are available.

By the use of a shift, similer to a typewriter shift, thiry-one new meanings may be assigned to the combinations, so that a total of six-

ty-two characters or signals are available.

37

4225 2 ao PN 0 Se eae Vay) 7" cn

vé

YHIAAPAINT YPULTHIEI TO MaTeye MUSAGOM FHT

{dsort fovea tI tro mrot. gated eefod feet -steqo edt yd heottom esno ts ef ti: ,ertmeo0 -bethemor od aso bre tot

t emottarotreq oft .8000 AAT detdw ,ebos tinu-evit edt to msfq sdt wolflot aid? .28.q ,eqst to elqmse odt mo movig at fose tot oenssoed shoo tins-evit s belfse af evtt to Latot s at eredt. ,xetostado to.tetiel af notre td yeunsld to eefed redtte ,elevretat eetonebh bas ,mret tretted a to tasw tot bees at eiT. .bedonuq et ofod om ototw noftsool ytevs) -tetet tot bevedmrc eis atwemele 19 alevrotat ed? .egat odt agotos (@ Bas ,.4.48 8). £ some janoktsaidmoo eme-ytitdt to wolfe elnemole evit sefdslteave ers eretostads smo+yiridd , eomed totixrwegyt s’ot ralimte ,tiide es to sen edt yf bedtgtees ed yan esalnecom wen emo-yridd ,ttide -xfe to Ietot es tadt os ,enottsnidmoo edt ot

-oldsitsyvs ers afsngie to sistosrado owt-yi -

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

Besides the actual charac- ters which are to be transmitted and print- ed at the receving station, the code algo includes several operating signals, which govern certain functions of the printer a- side from its regular printing movements. These signals are: space, carriage return, lining, shift, and rub-out. The space sig- nal causes a space to be left between suc- cessive words of the printed messace. The carriage return is used when a new printed line is to be started. The lining signal causes the printer to turn up a new line, just as is done in the operation of a type- writer. The shift signal causes shift char- acters to be printed instead of the normal characters; the printing of the normal char- acters is restored by the space or the car-

riage return signal. The rub-out is used

38

YHTAROSIET OUITUIALT TO META Ye MUSUIOM aaT

-oateulo L[estoe oft aeebteod -tattq has bettimenars od ot ote foftdw atet oels eboo odd ,cobtste gatveoer odt ta he dotdw ,elenstea setisreqo [ateves eobsfont -8 totairg et. to enoktonst aisitos arevog -atnomevrom gattateq tafsser ett wort obte : stutter ensinrmo ,soasqe cers aleanate seed? -gte sesqe eT .tuo-dort Sas ,ttide ,»sototl -ore moewted ttef od ot onmtet ie absien fen ed? ,egsacem betaitq oft to ebrow evisseo hetaitq wen & cenw bees af atuter sgsivsso fergte gatetl eff .betrate od ot eb ombt

in . ,emkl wen sa qe mot ot. totairg eft mosses + a) oeqyt-s: tor ROLMATATO edt mb enoh at as tent |

| -tedo titde asaueo Langte ‘Wide ed? teem io (¢ Lemrom ect to, besteqk betaiyg od: ot anotee ree a tnefe, Lene ost, ett 20, anttabeg ot, am a

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

39

when a mistake has been made in perforating the

tape. The tape is run through the perforator again, and the erroneous letters are punched out. Note that the rub-out combination of hole is the only one comprising all five intervals; hence, any other character contains fewer hole and can be punched out. When the printer re- ceives the rub-out signal, it remains inopera- tive or "marks time” until a different sienel is received; the printer then performs its us- ual functions, just as it did before the rub- out signal was received.

THE PERFORATOR. The tape is punched by means of a keyboard perforator. The general performance of the machine is as follows: The actual punching of the tape is done by a row of six pin punches which face a die; the tape passes between the punches and

the die. Five of the punches are for the five

S

s,

YHTAAPRIR?T PLITHIAL {TO METEY2 MUSAAOM EAT

eit satterotreq ot sbsm meed sant odatetm 2 coeriw sotstotireg edt daugorit ocr af oqst edT .oqst boedoasq ots etottel exsosnorre oft bas ,aisaus eeLlod to mottsatdmos two-dur edt Tadd otoll .ts0 seleviotnk evit [fs antettqmos emo yimo edt et ,20fod tewet entsinoo tetoasredo tedto ya’ ,soned -et tetmixng ont med% stwo fofenng of mao bia ~stoqomt amisner di .,fergte tyvo-dst edt eevteos {srgte tastesttib e [tian "omttd axlrean”" ro evit -en edi enrotreq nedt retnira edt yhevisset ef -doxr odt ototed S5rb tf es taut ,emottonst Lar ebevieosr esw L[eagta Tso

eit eget et? ,fOTAROTAET BHT stotatotres hSrsodyet s to ensem yd herfonsg as at ontdoam eft to eomamrotreq [steaes edT ef ogst sdt to gnidonsq Isetoe edT vewolLlot s eset dotdw sedonng atq xte to wor ‘ vd ectob bra esdonugq eft coowlsd eosesg eget edt jofb

evit oft rot exs eedomnq edt to evil sath odd

es esyu ik: * : tie

40

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

code holes, whereas the sixth is for the

feed holes. An electro-magnetic hammer forc- es the punches through the tape; on the back or return stroke of the hammer, the tape is advanced one feed hole, so that a fresh sec- tion is ready to receive the next series of perforations. Different combinations of holes are selected for the different characters by a selective mechanism worked from the key- board. This mechanism operates as follows: Between the hammer-head and the punch pins exists a small clearance, in and out of which five rods or punch levers slide independent- ly. One punch lever is provided for each of the five code punches, but none is provided for the feed punch. When certain holes are

to be punched, the corresponding punch levers are left between the hammer head and punches,

filling up the clearance. On the forward stroke

Ob

YHIAHOTIZT OMITUIAT TO MRTEYe WIARAOM FHT

eft tot et dixte edt esstedw ,selod oboo -srot otmed ottemasm-ortosfe aA .aeLlod’ beet Noed odt mo pedst edt davouwlt eerdomeq edt es et east odt ,temmed edit to exotte orrtet to -96e deett « tedt o8 afoul best emo BSesnsvbs to settee txen oft eviteost of yhset ef nott aefod to enottsatdmos tasetettric senordsrotreg yd erotoarsds drorettib edd tot hotberee ove Lyed oft movt bettow meinedoem svttesrea 8 tewolfot a8 eetaredo metnedtoom etd? .htacd oe «s eat douva oct ae basd-tommed oft moowted dotdw to two bas mt ,soneteeld [lama s ateaixe -trebteqobat obife atevel deovg to abot evit to dese tot hebivowq at revel Sousa end ee Bebivotc et omon tud podonng ae et ott 3 eee ‘ore eofodt atetrtso mod sons Boot eft tot 3 a erevel donug acfBrogesrtos éat ,Setfoanq ed of , eotomng baa feed remmect edt aeewled ster basis eforte brewtot edd m0 Lesneteefo bail eid went

41

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

of the hammer, the pins are pushed through the paper. If a hole is not to be punched, the punch lever corresponding to that hole is withdrawn from the clearance between the hammer and punches; then, on the forward stroke, the hammer enters the clearance, but not far enough to strike the pin. Hence, no hole is punched by that particular pin. The feed holes are always punched; the selec- tive mechanism has no contol over the pin which punches the feed holes. The rods or punch levers are controlled through a series of levers from a keyboard, similar to that of an ordinary typewriter. The keyboard also automatically control the electro-magnetic hammer,

With the idea of the general functions of the perforator in mind, we can

now take up a discussion of the machine in its

ie PEE eo

fs

YHTAROAIAT DUITHIAG FO MATEYe MUAAHOM TAT

devouwdt Sbodewa ote eaie sft .,tommadt eft to bedonug ed ot tom st olfod e tI iseqsq edt ofod tedt ot antbooceet1ros revel donuq odt eft neswisd sonerselo oft mort mwstidtinv et Sterrot edd mo ,nodt :esdouug fae tommsd ,somerssf[o edt eretme remmead edt ,eforte ,e0meH .mitgq edd exitte ot davone rst ton tud iq tefsolireag.tadt yd bedeasq st efod on -oolfee edt ;hedonsg eyswie ere sefod beet odT aig edt tsvo Lotion om ead me imedo om evit

10 ehor off .eslod hest odd eedomuq dotdw esiree. 8 dasordit Belfottaon ere etevel dong ted? ot telimte ,Srsodyex a mott erevel to cele breodyex en. .retirweqyt yrantizo as te ettengsm-orteele edt Lortaes ylfeottanciss tate it eT emmedt

Leveneg ent to sebt edt MtkW 0 yey neo ew ,batm mt roterotieq edt to poston i) ett mt eidoam oft To eakone gets 8 Waitara 3 ron

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

practical form. In this entire discussion, rough sketches will be used to show the gen- eral construction of the parts, but these sketches are not intended to represent the apparatus in detail; the accompanying photo- graphs of the machine show the details of construction.

GENERAL LAYOUT. The perfora- tor consists of a hollow cast iron base, on the top of which are located the hammer and punch mechanisms and the tape reel. The key-

board overhangs the front of the base. Some

of the connecting levers between the keyboard

and punch pins are inside the base, whereas

some are on top. Fig. 7 shows a top veiw of

the perforator; the different parts are iden-

tified in the sketch. THE FUNCH PINS. At the lower

left-hand corner of the base are the punch

42

ss

YHIAHORIAT DEITHIAI AO Mateye MUAAHOM aT

-toteavoeth etitas etdt al. .mrot Leottoarg -~neg edt wode ot hDsev ed [fitw eedotete. darort eaedt tod ,etreq edt to ootteutdedos [arte eit tasserqsr ot hebrotnat ton ers eeslotede -otodg goiynsqroces eft :{isteh at extstsqqs to aftsteb edt, wode satdosm edt to efgerg »coftonrtedos -stoiteg edT .TUOYAL TASm URS ae} mo ,9aed moti teso wolfod s to etetenos zo¢ bas tremmed edt Setsool ets. dotdw to got. edd -you ofl .[ee% oqat edt bas, enalasdoom Hoos emoe .oasd edt to taoxrt edt agasditevo hisod Srsodyoxt edt seewied erovel grttoeinos..edt to esotodw ,csasd eft ebient ers eatg donug bas to whev, got s awode ¥ .gtt .got mo erg moe -mebt sis satis tooerettts edt jrote rot req oat » 9 -etotete eft at betttt tewol oth th, .2UTT BOUOE ABB oy won che eee: Honig, edd. ets. oasd, nity shcndbase boedetteL 4

43

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

pins and die. The punches are of steel, about one-tenth inch in diameter by one and one- fourth inches long. There are five of such pins for the tape contact holes, and an ad- ditional smaller pin for the feed holes. All six pins slide back and forth in guide holes bored through the face of a small block. The idea is illustrated by Fig. 8, where B denotes the guide block. The block is[_-shaped, and across the open face extends a cover plate, HE, also bored with guide holes for the pins. The die, D, lays over this cover plate. The two are channelled out slightly so that the tape can be drawn along between them. The pins ordinarily project behibd the back face of the block, and also extend, at their op- posite ends, nearly through the end plate,

E; they do not, however, extend into the tape

channel. The hammer strikes the projecting

eh

YHIAADHITT QUMITAIAT TO METCYe MUASHOM HHT

trods .Leets to evs eedoonq ofT woth Sas ent -ero bas emo yd rtetemeafh at dont ditnet-oeno foxa to evit ets ered? .smol eodont dirsot -5a ms bas ,aefod fordabe eget edt rot eat [LAiseelod boot edt tot miq telfeme L[anottrs eefod ebies mt dtrot Bas aosd obife entq xfa edit .woofd f[feme s to goxt odt dgrorit hetod astomeb G& etedw .8 art yd botertes{[t et sebt bas’ ,beqede- jet xoold ed? .footd ebtag edt ,eteala "ovoo 2 Bbaetxe eset meqo edt eeotros -anig edd tot gefod situg dit berod oefs ,f edT .6telg tevoo efdt revo eysl .c¢ .9tb ext edt tedt of yltdatla tso bolfLennsdos e212 owt ‘edT .modt asowted aoole swath of neo eqat eset dosd edt Sdided toetota ylitenthro emt «go ttedt ts ,baotxe cafe bas ,foold edt to, otela fre edt davon} yfrsen ,ebae dtteod eqst at? otat bratxs ,tevewod ,tom ob yedt 32% aatioetor odt eoxttte roomed od? .feamede

aa. eae

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

ends of the pins, and drives the pins across the channel into suitable recesses in the die; if the tape is in place between the die and end plate, it is of course punched. The punch ends of the pins are slightly hollow-ground

so as to give better cutting edges.

The method of returning the pins to their original positions, on the back stroke of the hammer, is also indicated in Fig. 8. The feed-hole pin, F, is rigidly at- tached to af -shaped crosshead, C, which slides back and forth in the guide block; the crosshead is normally held at the rear of the guide block by the spring, S. The for- ward stroke of the crosshead is limited by its lug (the stem of the "1") striking the end plate, E. The croddhead is also bored with holes for the punch pins, but the fit

between the crosshead and pins is so loose

44

AL

YHUAROAIAT: MMITMICL TO METEYS MUSAZOM ANT

eeotos aniq ont eevith bre ,emtq. edt to ebro ;9L5 eft at eeeecost sldetinog otnat Iennsento oft has efb ett isowted seefd mt at sqet oAtT TE domuq off .bedoanq oersoo to af ti ,etslq bao Brsorg-wollod yitdatle ete antgq edt to ebas. -cogbe anifive tetted evig ot as 08

ed? gartarstexr to bodtem ext dosd edit mo ,exottieaoq Leniygiro tredt ot anmiq’ at Betsofiat oels st ,temmed edt to sdorta’ -ts yibtatt et .& ,atq efond-beet ed? .8 ait ffotdw .0 .bsedeeoto beqede-~ 8 ot betoat “ytooltd ebbing edd ot dtrot Sas dosd eaebile rast oft ts bled qflemrom et Ssentehoto oft -tot of? .2 ,antrtqe edt yd Moold ebtusa sft to wd Betimtr at baadecors eit to eslovte brew edt gatutxvte ("I" edd to mote ont) ‘anf att Betod oafe at beedtibors ef? .f ,etesla bas Fit edd stud ,ento devrg eft tot eoefot Atiw

geool oa Bt enty Bae heedesoto ett asewted

hh SPS rare gel BS 1 ee NRE

45

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

that the crosshead slides forward freely, without pulling any of the pins along with it. Each of the five pins is fitted with a small collar, which rests against the twck face of the crosshead. The crosshead ordin- arily bears against these collars, so that the pins are held in their extreme back po- sistion clear of the tape.

In the operation of the ar- rangement, after the crosshead has started on its forward stroke, any of the pins can follow, in case they too have been struck by the hammer. The crosshead stays ahead of the pins until the end of the stroke, and the pins go through a punching movement the same as though the crosshead were not pre- sent.On the back stroke, however, the cross- head strikes the collars on the pins and

carries all the pins back to their original

os

YHIARDELST PUITUIAL FO METEYS MUARHOM AHT

.YLeert brewiot goebife Ssenleeoros efit tadt dtiw anoles entq eft to yas amifl(uq. truodttw 8 Atiw hottit et eatq evitt edt to dosi .tt wo sf odd tanteses eteert dotdw ,relloo [lame

-aibxo beedegoto efT .fsedesors edt to esst Jadt of ,atalf[oo saedt temiszs ataed yLite -og Zoed omertxe x tedt ot Bled ors entg ont -eqsy edt to reefo mottete

-18 eft to mottareqo edt al Hhetiste ead Ssedesoro. edt totts ,trome'gcet meg ant edt to yre .exorte brawrot ett mo dovite need eved oot yedt caso at ,wollet to beeds.eyste bsedezoro edl,.commsd-edt.yd Sas eodotte ect to bne edd [ives anigq edt edt tmemovom,guidonng s dgsormt og aentq edt -9tq tom etew bsedesoto edt dguodd as omse “spore edd .tevewod ,giorte aosd odt a0, tn08 Snes acta edt mo areifloo edt eeiirte beed

featgtto tled? of toad eatq edt [fs aetriso - | : ,

46

THE MORKRUM SYSTEM OF PRINTING TEIRGRAPHY

positions. A feature which should be noticed here is that at the end of the forward stroke, the pin collars strike the crosshead, and their travel is thereby limited; otherwise, the pins would drive into the die and soon loose their cutting edges.

The method of starting the crosshead on its forward stroke is also ap- parent from Fig. 8. It will be remembered that the five contact-hole pins are not struck directly by the hammer, but instead, small interference rods are inserted between the hammer and the pins, so that the rods are struck by the hammer. A feed hole, on the o- ther hand, must be punched at every stroke of the hammer, and hence no punch lever is provided for the feed pin. Instead, this pin projects beyond the others a distance slight-

ly in excess of the thickness of a punch lev-

ob

YHCAADEILT DUITMMIAT TO MeTeYe MUMAOM TA?

heoiton ed Si{yode do tdw esriteset A semoftieog ,otorte hrewrot edt to Bas odt ts tad? at erod ttedt Bas ,bsedesoro odd otttte arsf[Lloo mig odt eatg edt ,setwredto ;betimil yderedd er Lovett ttedt seool mooe baa ef5 edt otmit evith bisow . -2ogbe gaitiso

edt enitvate to Bbodtem sdT' -qs oelfs at etorte Sreawrot ati mo bsedeasots heredmemet od £[fiw tf .8 .gtt mort tneteq fourte tom srs entq eLod-tostmoe evit edd. tadt If{eme ,hbestent sud .remmed edit yd yitoorth eit oasewhled betreent srs ebor sonsretretat ets ebot edt tedt oe ,satq ond Sas cremmed -o eft mo {efod best A .rommed edt yd aourte exorte yrove ts bedonuq ed tenm bead redt et revel deonvq om eonmed bae ,tommed ,odt to tigq etdt ,bsetenl .atq hset atid tot Sshtvorg -trigife senateth s etedto edd broyed -etoetorq -refl domuq s to esemsoidt edt to seeoxe at yl.

47

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

er. Therefore, the feed pin is struck by the hammer before any of the punch levers, so that the feed pin and crosshead lead the other pins throughout the stroke. It is ap- parent that with this method, the proper movement of the pins is not interfered with by the crosshead.

THE HAMMER. The hammer mag- net consists of two solenoids, designed for 110 volts, direct current. The solenoids are placed horizontally at some distance behind the punch pins and in line with them. The arrangement is clear from Fig. 7. The two coils are supported from the base by 4 brack- et, which is attached to those ends of the Goils adjacent to the punch pins. The solen- oids are fitted with movable cores or plung- ers, which slide in and out of the rear ends

of the coils. A yoke connects the cores, and

Th

YETAROTIET DUITHISY GO. Maeve WURAAOe ERT

eft yd Momrte ef miq) best edd YototeredT .19 . oB! ,etevel donug eft to yaa stoted roamed edt haa! hsedesots bas atq beet odd tedt -qz at tI ,exotte odd tuodasordt entg tredto teqorg oft .bodtem efdd ditw stadt Jasteg dttw berettetat tom st satq odd to tremevom » .Beedeeoto ett yd

-gam-tommed eT. .HEMMAR: ART: TOt.Bomgtesh ,sbifonelLoe owt to etetanoos ter ets ebtonefloe od? stmstiso gosrih ,atfov Off baitded somaterh omoe $s yifatadstromd Soosl¢ edt ..medt dtiw eatl at baa extq dontq sdf owt of? .V.2hT mort tselo at tasmegratta -toatd « yd saad edd mort botroyquae eta eftoo eit. te shas oa0dt ot hedosits et dotdw te -seloa edd .amtq donag edt ot tnenshbe @: : : -gariq to eetoo sldsvom détw bettit. en

shee, seamen feo nahn mk ehte: SPOR SF 4

bos ,eeroe edt atsennoo exoy A. sltoovedt to" .

48

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

from the center of this yoke, = plunger rod goes forward between the solendids, through a guide hole in the bracket, and terminates in a round-headed nut, N,. A hammer spring, acting against the magnet, normally keeps the cores drawn partially out of the coils and the plunger rod in its extreme back po- sition. When the coils are energized, the cores are drawn into the coils, and the plun- ger rod thrusts forward toward the punch pins. The hammer solenoids are controlled automatically from the keyboard.

The hammer itself is a hori- zontal steel lever, pivoted at A (see Fig. 7), and extends into the clearance between the end of the plunger rod and the punch pins. Thus, when the plunger rod comes forward, it thrusts the hammer on ahead of itself.

The construction of the ham-

Ob

YHLAHOALTET DULTUIAT TO METeYe MUSAHOM HHT

hor tegmutaq s ,ovoy etht to retas0 ent mort davorts yebtonafoe edt seewted brawict seog eetentarre? bus ,tefoard eft xt efod ehiva’s ,adince vemmed A.W , tum bebsed-hnsot e@ mt eqeer yilamron , tenga odd tencisas uitios aftoo edd to tuo ylisttisg twerb dstoo edt -og Hosd emexrtxe ett at hor tegneiq odd bas ext ,bostarere ers effoo oft sodY .aottte | -onlq edt bas ,efioo ‘edt otth mwath sts eerde ne doasq odd Brawot Brawrot aveutdd hor res 3 bellortice ere eblodelod tenkied ed? sant -5xaodyex edt mort yLlsottamotys Pie es: ~tiod @ et tfowt! tommed ed? © 9° * | ae

o( .Qlt cee) A te botoviq ,revel Leote Istnos : ‘eit meowted sorersefo ent otmt ehmetxe Bae “lemtq donsq odt ae bot tosasfa edt Yo bme |

)) .brawrot evemos Bor regax tg att aedw esd? ( \Sfeadt to beeds no remax odd eteotdt $2 oe ‘smad edd to nottowttenos edt) 8 te tig

49

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

mer is shown in Fig. 9. As indicated, the hammer is channelled out along its length. The channel faces the punch pins. In line with the pins is cut the rectangular notch, B (see Figs. 7 and 9). When the end of the hammer is pushed forward by the plunger rod, the ends of the punch pins enter the notch, B, The channel and notch furnish the clear- ance, before referred to, between the punch pins and hammer. Note that the bearing at A, upon which the hammer is pivoted, is offset from the center-line, so that the bearing stud is well clear of the middle of the chan- nel. "

THE PUNCH LEVERS. The five interference pins or punch levers, which slide in and out of the clearance between the ham- mer and the punch pins, are merely square steel

rods; they move lengthways of the hammer through

a") '

Ve) ore! <> a ae

eh

YHIAADEIAT DUITHIAG TO MATCYa MUAAZOM HRT

edt .fetsotint eh .& «ett of awode ef rem Ateool ath gaolea tuo bellomnsdo ei temmad entt al .antq dogsagq edt esoet Lormedo oT doton taleanstosr sft two ef ent ot dtiw eft to bre edt mod! .(2 bas Y .egtt ese) & ,bor tegaulg edt yd brewrot bedeng al remmed dotom edd tetne antgq doasq oft To ebme ont -tsefo edt detotyt dotom bas fonneado edit .& sonugq oft meowted ,ot bertetet stoted , eons A te guitsed oft tedt eto jrommat bas eniq dogito ef ,betoviq ef temmed edt dotdw nogr antteed ofirtedd of ,enti-retaso edt mort | -nado eft to efhbim edt to tsefe Liew ab bute =~ e aera: 7 fer He

evit ef? .etiVal HO“UT HHT efile dotdw ,erevel doauq to amt eonetetrotat. -med ont noowtod eonstselo edt to two Bas, at

Teste erempe:xforem ets ,emiq omg odt bre tom dgrotdd renamed edd to eyewdieael evom yedt jebot ~

50

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the channel. They are arranged in a vertical row or pile, so that each one is in the hori- zontal plane of a punch pin. The levers are numbered from 1 at the bottom to 5 at the top, corresponding to the same numbers of the code elements. The punch levers extend just far enough along the channel that their ends cross the notch in the channel, and thereby fill up the clearance space at the tack of the pins. However, each lever may be withdrawn from the channel for about half an inch; this movement is sufficient to re-establish clearance. SELECTIVE MECHANISM. The meth- od of moving the punch levers from the key- board is illustrated in the isometric sketch of Fig. 10; this sketch, for simplicity, shows the complete links for only one punch lever,

and shows only one key. Hach key is the ter-

minal of a long arm, K, the back end of which

O38

YUTAMDAINT AMITUIAT LO Maree MUAAOM ABT

feotsirev s af besnstre ots rod? -fomisdo edt ~frod.oft mt et ono, dose tedt oe ,eltq.1o wor ete erovel off .miq donuq s to onelq Isitnos got edt ters ot mottod edt te £ mort botedmia eboo edt to eredgum omae odt ot anibmoqesetios _ st test baotxe exovel donsq edt .etmomefe 2B0TD abtre wiodd tedt Lonnedo oft gaols devote qu.[fftt yderedd bas ,fennedo edt of doton oft -egtq ent to aoa edt. ts .cosqe eouatsslo edt edd siott, owerbdtiw ed yem revel, tose . TevewoH taemevom etdt jdont os iled twods tot Lonnsido -eoretselo delidetas-et of daoototitue ef

-ddem eiT .MeIMAHORM SVITOMIAE . fo -yor odd sort exevel donsq eft aatvom to bo dotese otutemoat edd mt beterteu[{t et braod

awode ,qtiotlamie tot .dotexe, atdhj;0L sett 20

<tevel sonsq emo Yoo tot exatt otelqaos, edt

_) *tet edt ef yor dost «yout eno Yao aworia beta” he P

| dotite to bas oad oni .X jure gxol 2 to fecta ret

51

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

is mounted on a shaft, S. The key lever, or arm, has a projection, P, which rests on a large rectangular strap-iron loop, L; the loop has no back side, but instead, the two ends of the strap are supported by two bear- ings, BB, as shown, The arm, F, is attached to one end of the loop, and rises vertical- ly. The upper end of the arm, F, is slotted, and engages the short end of the bell crank, D, The crank has a suitable bearing at =E.

The long arm runs forward to the punch lever, and is pivoted to that lever at A. Tracing through the link movements, we find that if the key lever is pushed down, ss it would be by the depression of a key, the front of the loop, IL, is also pushed down; this movement brings the upper end of F forward, and with it, the short arm of the bell crank. The long

arm of the bell crank is thereby drawn toward

YHTARORILT DEITUINI IO METeYS MUSXHOM HHT

to ,tevel yet eT .c ,ttede s no botvasom ef 8 mo ateer dotdw .2 ,nottvestorq s esd ,mre edt if ,qool mott-qette tefesastoer estel owt oft ,isetemt tud .,eblta Axoed om esd qool -teed owt yd hetroqqve ers qatte oft to ebae bedostiea et ,F ,orrea 6d? .awode se ,74 ,egat -[sotixey seett bas .qooL edt to Bre smo of bottolea at .f ,mra- eft to Soe sreqqy ed? st ~Mnato [fed sit to Bae trode edt eesgescs Sas 2 te scttrsed efdatise s ged Hoero eit sc tevel donvd odd ot Srawrot earr ors anol dT grtosxT .A te tevel tadd ot betovtq at bre tf tedt Bott ow ,etasmevom satl edt Agro? ed Bblyow tt ea ,mwoh bedeugq ei revel yer odt oft to trort sit ,yo! s to moteeerqeb sit yd tnemevom eidd ;awob.bedenq oe@fa et ,f .qoot

dtiw bose (brewrot I to boe reqqs edt egaind gaol ed? .Aneto [led edt to mre trode edt , tt brswot nweth ydetedd ct vaste fLed eft to ars

52

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the right, and it pulls the punch lever with it. This movement of the punch lever is the one de- sired. All parts are returned to their original positions by springs, not shown in the figure. The controls for all the punch levers are the same: each punch lever has its own bell crank and loop movement. In Fig. 11 is shown the complete

selective mechanism with the exception of some of the keyboard keys and levers which are left out to simplify the sketch. The method of nest- ing the six loops and the arrangement of the bell cranks should be noted especially. The sketch also shows the several fingers which each key le- ver carries. These fingers point downward, and each rests on one of the loops; hence, the depres-

sion of a key simaltaneously depresses several loops, and, at the same time, withdraws several

punch levers. By this action, a key controls such

3d

YHIARZORIAT DUMITUIAL TO METSYe MUSAHOM DHT

ti adtiw-vevel donq edt ellinuq th bos | tigty oft -9b ono oft et revel donug sit fo taemevom ata fantakro tted? ot bBenruter ots etraq [LA .berta -stsgit edt af mwote gon ,e2gnirga yd aeaottheog adt sts eatovel doroq edt £f2 tot efLortmoo: oi?

: Unsto ffed owo etl asd tovel doacq dose > emae ~tmomevom qool hrs stelqmoo edt mwode et LL .ght aly, meets | emoe to amoisqeoxe edd dtiw metasdoem avitoelee tTtel ere dotdy etevel fora eyed brsodyed eft to -taen to hodtem sit .dotefe sdt vitiqate ot tro edt to tmomegasits edt bas aqool xte edt gat

fotede eft .yf{stosqes betom ed bivorle axneto [led Rat vow fore to £ chy: exogalt: fsvsvee oft awode osfe . faa ,brewnwob tatoq etegalh oseXt ssotttes Tov - -aetqeb est ,eonedt :2aqool edt to Ofr0, HO: eteon, soe, Latevea asaeenyed ufesoonst fente: yet! to ee r

farevee ewsrhdttw |, omtt omae: oft te: bee ay sa : dove efLortnoo, yet sy, mottos eld yh s erevel 7 Da

53

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

punch levers as will cause the proper holes to be punched in the tape.

The hammer control is indi- cated in the same figure. In addition to the five bell cranks, there is a sixth lever mounted with them and similarly controlled. This lever is the top one of the bell crank group, and is operated from the outside loop. The top lever has no long arm extending to a punch lever, but instead, consists of a single arm, identical with the short arms of the bell eranks. This arm controls the hammer magnet through the series contact shown. One point of the contact is stationary, whereas the oth- er is carried by the lever just mentioned.

The contact is normally open, but when the arm is moved forward, by a depression of the front loop, the contact closes and connects

the solenoids to the source of current sup-

YHTAMDAIAT DAITMIAL TO METeYe MUSAAOM FHT

aefok tecorq eft eeseo [ftw es arevel donnug -ogst eft at bedonug ed of

~Ehat at Lortaos trommad ait edt ot mobtifis aI .statt omee edt mt betsoe vtevol dixta es at eredt ,edimeto [fed oevit eSellortaos yfralimts bas medt dttw betarvom Aneto [fod eft to exo got oft et revel etdAT -qool ebtatro edt mort betsteqo at Bae ,quorty 8 ot antinetxe mrs srof om ead tovel qot eT efgste s te etetenoo ,fhsetent tud ,revel donuq {fed oft to amrs trode odt dtiw Isottmwedt ,mrs temgsm temned edt eLfortmoo mra eidT .etinsto tatog enO .mvwote tostnoo sasirea edt davordt -dto edt essredw ,yrscottate at tostaon eit to eSemotinem test revel edt yd Betttras et te eft monty ted ,neqo yflamton et tostnoo ed? edt to moftasetqeS s yd ,fSreawrot Bevom ef mrs etosanos Bas esects tostmoo eft ,qoof taort

-que taertso to servoe edt ot ebtomefos edt

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

ply. The contact is adjusted to close just after the punch levers have been withdrawn by the bell cranks.

As for the location and mount- ing of the link mechanism on the machine, the

bell cranks and contact are situated an the

top of the base, as indicated in Fig. 7, where-

as the loops and keylevers are inside the hol- low base of the machine; the levers F of Fig. 10, connecting the loops and bell cranks, ex- tend upward through slots of the grid, G, as indiested in Fig. 7. The mounting of the bell cranks on the vertical studs is also apparent from Fig. 7.

The method of suspending the loops and key levers in the base is illustrat- ed in Fig. 12, which is a veiw upwards at the bottom of the machine. The six free ends of

the two sides of the loops are mounted in the

54

YEIAAOAIRT DALTHIAT TO METCYe MUARAOM HHT

test asofo ot betesths et tostaoo edT .yla awethditw seed evad erevel donsq edt retts -aineto [fed edd yd

-iasom Baa aotssoof edt rot #2 edt ,eatdosm edd no matnadoem eat{ oct to amt edt om betsutte ets tostmoo has exnete {Led -otedw ,." .nti at betsotbat es ,seaad eft to got -fod edt ehbtent ete erevelyed bae scoot edt as aft to % erevsl odd jeatdosm eit to casd wolf -xe ,avesro [fed has eqool edt anttoennoo ,OL es .© ,bixvg aid to stole danotdt Srawgs bast {fed edt to gattavom of? .¥ .att at botaoliat tastaggs oasis at ebsta [sottrev edt ao etnats eV. .gtt mort

edd gatbhneqese to hodtem dT -tettas([l?t st eesd odt at atevel yet bas sqool ed? ta shtawqy wrev a ef dotdw ,&f .@tt at be to alae sett xte ed? .entdoam oft to mottod

edt mt hetavom ets aqoot edd to eohts ows odd

pf A oe ee a fae! 3 * 4 a4 wy

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

two bearings as shown. Washers or spacers are pleced between adjacent straps in order that there shall be no interference between them. The loops are held up snugly against their backstop on the under side of the base by return springs. The idea is eleear from Fig. 13, and needs little comment. The rod, R, of Fig. 13, runs the full length of the loops. This spring support allows the front of the loop to be pushed down by a key lever, but immediately returns the lever to its normal position when the pressure is released.

The mounting of the key levers is similar to that of the loops, and is shown in Fig. 12. The back ends of all the levers are strung loosely on a shaft, 8; the levers are kept separated on the shafts by spacers. The key levers have spring returns, similar

to those of the loops. All springs, both of

55

ou Cs

YHCATOLINT OUTTAIAI FO MATSYS MUAAHOM ANT

eTs ateosqe to ersdesW .mwode es eanttsed ovt seit teSro at agarte tnesestis moewted beoslq emendt moowted sonetetretar om ed [fade eredt tteit tveateas ylaune qu bfed ere eqool eft qd eead edt to eshte tebas ods mo qotexosd est? mort reafo et sebt ofT .eantiqe arustet to ,f ,hor edT .tnemmoo s{ttiil aboom bas ,éf -2eqool edt to dtanel [fut eft env cL att edd to taott edt ewolfa troqaze aairce ald? txud ,tovef yout a yd mwoh bedsersq ed of qool fenrrom ett ot tevef odt eaanruetor yiststbhemnt | eDbosseler st orteeetq sdt aodw nottteog atevel yet edt to sattarom eT ) mwode at bas ,aqool adt to tsdt ot tafiimte at etevel edt {fe to aime doad ofT .SI .utt at arevel edt ;& ,ttede s mo y{ssool anurte ets ~eteosqe yd eftedea edt mo hetersqes tqex ors ‘siimte ,anruter anitxgea evad erovel yex siT

to diod ,sgaitqs [fA .eqool edt to saodt ot

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the loops and key levers, are anchored to the rod, R, of Fig. 13.

THE KEYBOARD. The key levers terminate at the front of the machine, have key buttons attached to the front ends, and thereby form the keyboard, The plen of the keyboard is cleer from Fig. 7. In a general way, it follows the plan of the standard typewriter keyboard, but as only upper case letters are used in telegraphic work, addi- tional characters are supplied instead of the two separate styles of letters. Notice that besides the actual printing characters, the keys include the operating signals, such as carriage return (CARRET), lining, and oth- ers.

THE TAPE FEED. The method of feeding the tape may be seen in Fig. 7. The tape reel is normally supported horizontally on the top of the base to the right of the

56

ad

YHTAROEIRT OMITAINA TO MATSYe MUSAHOM FHT

ot betodons ete ,atevel vei Bas eqoolt edt -8f£ .2tt to .f , bot edt

etovel yew ofT .CHAOSYaA HT eved ,emtdosam oft to tnortt oft ts etsainret bos ,eise tnootrt edt ot bedostts anotind yox edt to asfgq eiT .fraecdyei sft mrot yderedt feteneg a ml .S .att mort <nele at breodyext Busbastea edt to malq edt ewoffot tf . Yaw ease teqas ylno ae ted ,brsodyet retliveqyt -tihbe ,trow ofdaatastet at pie ete etettel to beetent Sbetfarrea ere aetatostade [anctt sotto .atettel to nétete, piotcauie owt eft ~atetosrado arttcitq Isutos edt eehteed tact fove ,eafarnta anttateqo eff obsfomt eyed ent efto bae ,aatatt ,.{TEAHAD) mrvter onstytas 3s 879

to bodtem ef? .CanY FIAT ERT odT .¥ .g9f% ot mooa od yen sqat edt gathest yliataostrod Setroqque yiismrom at feet sqst

eit to tdgit edt of saad edt to qot edd no

5”

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

bell cranks. The tape unwinds from the reel, passes between the punch pins and die, and then passes between an idler or tension rol- ler and the feed roller. The idler is pressed against the feed roller by a spring. The idler and feed roller may be seen in Fig. 7 at the left of the punch pins and die. The feed rol- ler is a vertical cylinder, slightly higher than the tape is wide. It has projecting pins or teeth which engage the feed holes in the tape, so that the tape is pulled along as the feed roller turns. The idler is a second cyl- inder which serves to keep the tape close-up against the feed roller.

The driving of the feed rol- ler is accomplished by a ratchet and pawl movement, a part of which movement may be seen in Fig. 7. At the bottom of the feed roller, and rigidly mounted with it, is a

ve

YHLALTHSIET PUITHIAG TO MATEY MUSIAOM FHT

~leet edt mott ebatwoau east efT .axmato [fed bas ,9tb bee extq donve oft meswted eaeaag -foxr aotere? ro talht as seowted sesesq not Heseetq at relSt edT .reffot best edt bas rel telbt eft .grirtqe 2 yd tefflor best edt tantsas edt ta VT .gtl at nese ed yam refLor Beet Sra ~fot Beet efT .sth Bas entg donsgq eft to Hel svedatd yitdatfe ,rebatiyo Isofirev s at rel amntq axtteetora ead $I .eftw et oqet edt nadt edt mt seltod beet edt ousgnto dotdw dtoe? to edt se anofe beffreq at eqat edt tadt oa ,eqet -I[yo baoosee s et telit ofT wanted reffor heet qu-oa0lo ayat edt gqsex ot sevros dotdw tebat eteol[flot beet edd tantagea

-fot boet edt to anitvirh eT | « Ivaqg bee tedotet #2 yd hedatiqmosos st tefl ed yeu tacmovom detiw to traq a ,tnemevonm beet edt to mottod eft t4 .v watt aot neue 8 ak ,tt adtiw Setmrom yfbtatr See ,reLfor

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

ratchet wheel. A long pawl attached to the end of the hammer comes forward with the hammer on the forward stroke; the pawl hooks over a tooth on the ratchet, and on the back stroke of the hammer, pulls back the ratchet one tooth. This movement of the ratchet ad- vances the feed roller and tape one step. These steps are about one-tenth inch long, measured on the tape, which distance is suf- ficient to produce clear distinction between successive letters on the tape.

The punching, feeding, and selective mechanisms, so far described, con- stitute the essential parts of the perfora- tor. Experience, however, has shown the de- sirability of adding two more features.

THE BACK SPACER. The first of these new elements is the back spacer;

by means of this device, in case the wrong

58

83

YELAMORIZT OUILTUIALT TO MET2YS MUAAAHOM FHT

sit ot bedortisa [waq gnof A .{sorw tedotst edt -ditw 6Sreawrot asmos rtemmed edt to bas axood (waq edt ;esdorte brawrot edt mo tommed dosd edt so Bas ,tedoter sedi mo dicot & t9¥v0 tsedotat edt voad alluaq ,r9smmed edt to exorta -he teflotat edt to taomerom eidT .dioot emo etota enc eqat Sus ref{lor beet edt esoray ~amol domi dinet-eno tuods ets agete saedT “tse st soneteltbh doidw ,sqst oft mo bersesen meowted moktentteth tssfo eouborq ot tastott -9qet edt mo arettel avieasoorus

hae ,antbest ,agidonsq edT -foo ,S5edirogeb rat ce ,smetmadoen evitoelea -sxotreq edt to attey Iatinesae edt stuitte -o6 edt awode oad ,revewod ,eonstreqx= .rot .s9tstset stom owt untibe to yttitdarts

tetit ed? .AHOAIe BOAT FHT stecsqs unsd edd at atmemefe wena szedt to

ancotw eft sesso mt ,eotveh stadt to ensem yd

59

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

letter has been punched onto the tape, the tape can be backed up until the incorrect letter is again in the punch. Then the let- ter may be cancelled by the "Rub out" key. Thus, the purpose of the back spacer on the perforator is exactly the same as its pur- pose on a typewriter.

The movement is illustrated in Fig. 14(a), which is a veiw of the under side of the base. The stud which carries the feed roller extends through the base, and terminates in a star wheel. A lever and pawl, as indicated in the figure, are mounted so that the pawl engages the star wheel. Hence, when the lever is salen to the right, the star wheel is turned through a small angle. The star wheel assumes a definite position under the action of the jockey roller which

rests upon it. The movement of the star wheel

YHZAROGIET SMITUIZT YO MATCYe MURAHOM ART

eit ,eqst edt otmo bedossy, seed asd rettel toenroont eft (tins qu hezosad ed mao eqsat -tal eit moilT .donsg edd? at atreas el rottel -you “tno dof” edt vd beifeoaas od yeu tet edd mo ressede Xned edt to seogrsg edt , asd? ~tog att se omas edt yitoaxe et totsiotieq etotirwoqys 8. m0 920g

betartan{f[r at taemevom edt vehus edd to wrey sa at dotdw ,(a)Sl. .gtl at edt selirse doidw Bote eff .snsd eft Yo obta Bas ,seed edt davordt ehnotxe telfor heet .lweq Sas xrsvel A .feedw tata 2 at seteaturet os Setmcom ems ,otegtt edt at botsotiat as .eomel .foodw tetea odt eoasane {weq edt stadt edt ,tdaty edt ot bedeng ef tevel sit asdw -olats [lems s dysordd Semxut at feoedw tste sottteog efiatteh s asemmeae Leedw rste edt dotdw teflor yexsot edt te mottos oft tebas

feedw tate ed? %o txsmevom oAT .tt moqs ataer

60

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

turns the feed roller and tape back one step. The lever and pawl are returned to their originel positions by a spring. The lever projects from the base at the lower left- hand corner.

THE END-OF-THE-LINE INDICA- TOR. The next of the new features is the end-of-the-line indicator. This device gives warning when approximately sixty-five char- acters have been punched onto the tape; six- ty-five characters are assumed to constitute a printed line. When the signal is given, the carriage return key is depressed, so that at this point in the message, the printer will begin a new line. The device is there- fore seen to perform the same function as a warning bell on a typewriter. Before a mes- sage is started, the carriage return key is

depressed; this action assures the perfora-

08

YHIALORIET SAITUIAL TO MUTZYe MUSAAOM FHT

-qete exo aosd eqat bus reffor beet edd emit xtedt ot bomrutex ets Iweq Sne8 tevel eAT tevef ef? .anitqe e yd soottieco [anigize -ttel rewol edt te oasd edt mort atostorq etomros Sasd

-ADIQWI HNTI-RHT-T0-cue See edt et serstset wen sit to xem of? HOT eevia eotveb ald? .rotsotfat emt{-edt-To-bae -redo ovit-yvexte zletamixorg¢s asiw gotatsyw -xie j;eqst edt otmo bedonsg aeed saved aratos stgtivenos of bemsaaa sta aretostario eritexy? esovis at Lemste edt set’ .enti bstaira s tadt on ,beaserqed et you arvter ensirtas edt toeltatiq odt ,oasecom edt at tatog etdt ta -stedt ef ectveb ef! eat wea s miged [ftw 8 eg sottonut smsa edit crrotteq ot meee stot -eom & ototed ,tetitweqysd es mo [fed antatsw at yet ariter onsittas edt ,bedistea et ease

-stotieq ed? eetwees sottos atid ;beeeetced

61

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

tor and the printer being in phase as regards the lines.

The indicator is located in the base of the machine; the details of its construction are presented in Fig. 14(a). In this figure, the parts are in the beginning- of-a-line position. As shown, on the feed roller shaft is a small pinion, which drives a 65-tooth gear through the medium of an eaux- iliary or idler pinion. At each stroke of the hammer, the large gear is turned through the angle of one tooth, so that at the end of a line of sixty-five characters or signals, the large gear will have turned through one complete revolution. The gear turns against the action of a spring, U; this is a flat spiral spring, similar to a small clock spring.

The large gear carries a small

cam or disk, D, concentric with it. A lever, I,

fa

YHIAROAIAT SUITUIAT TO MATeYe MUKAHOM HHT

eitesret as eesdiq at gnited tetattg edt bas tot -sentl ent mi betsool st totsetiat exT etl to eltsteb edt yemtdoam ett to eaad aft mI .{e)bf .gt! at betaecerq ots mottorrtenco -getnotaed eft at sre atray edt ,etsalt atid? beet edd no ,mwodea eA .motitaocg eat{[-a-to eevirh dotdw .aotnta {femme s et Itade refLlot -xss as to mrifen edt derovdt ssen dtoot-d3 8 edd to etortea dose tA .wotmtq tefhi to yretit edt darordt hentot ef tae, estrsf edd ,rommed es to Bus odt te tadt on ,dtoos omo to ofgna ,efencate ro erstoarado eviteyixta to satl exo dasotdd bhearvt evead ({tw rasp egtal edt santsae enrst tees efT .moltinlLover stefqmos telt s at atdt 3U .aairge sto nottes sit eaatrqe doofo f[Iame s of taltmte .anixqe Latiqe {{eme # 2eelttss tseg ontel edT

el ,tevel A wtt dtiw otutnesroo ,T¢ ,tetb to mso

62

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

is held against the edge of the disk by a spring. An interference pin or stud projects from the face of the large gear in such a manner, that, as the end of the printed line is approached, the stud travels under the lever, lifts it off the disk, and raises it still farther till the contact spring of the lever strikes the fixed point of the contact. This condition is shown in Fig. 14(b). The contact is in series with an indicator lamp and source of current supply, so that when the contact’ closes, the lamp lights. The lighting of the lamp serves as a warning to the operator that the end of a line is near. The contact is so adjusted that the warning oceurs at about the fifty-eighth character of the line.

Special construction of the

large gear is shown in the figure, viz., the

iy) YHIARDEINT ORITMILI TO MATCYe MUANAOM AT

g yd wetbh edt to sabe edt tentages bled et etoetotg Sute to aiq eonotetretat mA .gaitge s dose xt tsen ontel edt to soad edt mort entf£ Betatxq edt to Bre oft es ,tadt ,tennam edd to brs afevert bute edt ,fetosorgqs at tt aseeteax brea .xeth edt tto tt attkce ,revel edt to aniztqe gosigoo edt [Ltt tediret {ftite etestinos edt to tatog bextt ed} aotints tovel od? JG)SL ght xk wore st sotdtbaos eld qus{ totsotint as Attw sotres sf ef tostaoo “ade tedt of ,yfaaue toeriso To eotvoe bas eft .etdeil quel edt ,eeeols Sostiroo edt ot natntrsw a as eovrce qmal edt to gatidell taem St omtf a to Sne oft tedt trotsreqo edt gatorrew edt tadt betestbs os at tostaoo edT totostsio dtdate-ywtlt edt troda ts sivese eoxtf edd To

edt to mottouttenxos Lstoeqe | edt ,.stv ,orsglt adv at owode et tseg eatel

63

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

lest four teeth of the gear are cut out; the last four teeth are mentioned with the under- standing that the teeth are numbered from the one in contact with the idler when all parts are in the initial or beginning-cf-a-line position. The reason for this construction of the gear is as follows; if all the teeth were in the gear, there would be no means of stopping rotation at the sixty-fifth charac- ter, and the operator might continue punch- ing. The rotation of the gear would continue, so that presently, the interference stud would turn from under the end of the contact lever, thereby releasing that lever and des- troying the warning signal. Hence, the last four teeth of the gear are cut out, so that when these spaces reach the idler, any fur- ther punchine of characters has no effect on

the large gear; hence, the warning signal is

YHTARDEIET SAITHIAT FO METeYe MUAAHOM FHT

eff ;tuo Tyo ota teen edt to dteet rset fteslf -rebay edt diiw benotinom ers dteet rs0ot teal edt mort hersdmuena ete dtost eft tsdit actiaste attrag [fs medwrofht sdt dtiw tostmoo at ano ent f-a-to-gatnntsed to [sttint edd mi ets softosrtesxoo satdt rot mosgser ef? snotttesg dteet edt [fs ti gewolfot es et rses edt to to smasem om od Blyow stodt . T8238 edit mt stow ~ostads ditit-ytrte edt ts noltistor gatqqote -donasq enattroo tigtm rotereqe edt Bas ,tet eouxttaoe bilrow tees oft to nottetor edT want bste soneretretat edt ,yltmeserq ted? oe tosiaco adt to bao edt tehoas mort aret bixsow -seb bea tevel tadit sntsesfer yderedt ,rovel veal add ,someH .[angte zatareaw eft satyort sedt oe ,tso tuo ets teeq edt to dteet rot -mpt yrs ,telbit edt doset seosqe esoedt nediw ao tootte om esd eretoerane to aatdensq tedt

et fenate antorew edt ,eonmed itsen surel edt

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

maintained.

The release of the warning signal is effected simaltaneously with the punching of the carriage return signal. The carriage return key operates the selector punching mechanism in the same manner as any other key, but in addition, the key strikes the end of a small bell crank, B, of Fig. 14 (a), at the right end of the base. Through the agency of this bell crank, the key push- es a rod, called the release rod, through a small distance toward the left. The release rod is connected at the left to an arm, H, which carries the idler pinion. This arm is centered on the stud that carries the large gear, and is kept in such a position by &@ spring, T, that the idler pinion is nor- mally in mesh with the driving pinion and the

large gear. But when the release rod is push-

64

hd YHLAROAIST QDUITMIAT TO MATEY MURAXOM FHT

Fentetatsm

gntatew eft to easefet edT edt dtiw ylavoscatfamte hetostts et Lacate efit .fangte oroter eastrreo edt to satdongg sotoefer eft estarsqo yet aroter esaetrrsas vie as tenray omee oft at metsaedoenm antdonnsg eeticrte yet edd ,gotttibe at tod ,yext tsdte Bf .att to ,&@ ,axmetrs [fed (fame s to Bae edt davord? .easd edt to bre tdsatr edt te ,{8s) -fasg yeu edt ,x¥asio [fed atdt to yonsss edt & davord? ,50r seselfer edt Beffso .hor 8s e9 easefer ofl .ttel edt Brawot oonmateth Cfeme eH ,mxs ms ot Mol sit ts betoennoo ef bor mrs etd? .wotatq refht edt aetrrso dotdw eit getrrso ted? byte edt no Bbetetmeo et moltisog # dove dit tqext ef bas ,1sen eatal -tom gt sotatq tefbt edt tadd .T ,aattqs « yd ont Bue mointg gaivith edd dittw deem at yifam

~feog eat bor easolor odt sedw tnd .rseg earal

65

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

ed to the left, it carries the idler lever and pinion with it. The idler is thereby thrown out of mesh with the feed roller pin- ion. This condition is illustrated in Fig. 14(¢). The large is now free, and runs back- ward, under the action of the spring, U, un- til it reaches its original position; i.e., it turns back approximately one revolution.

This movement of the large gear turns the interfernce pin out from under the contact lever and allows that lever to drop back onto the cam; the lamp contact is broken, and the warning therefore ceases. The backward movement of the large gear is stopped by the interference pin striking the end of the contact lever. Such a condition of the parts is shorm in Fig. 14(a).

In order that the carriage

return key need not be held down until the

3

YHIAMDE INT DAITHINI TO METeYe MUAAHOM FHT

revel terfht eft setarao tt ,stel eft of be ydetont at refit efTl .ct ditw motatq Sas -ata teffor Boet oft ditw deem to tro mwrorit alt ot Batartaus({[t at mottihmoo etd? .mot -tosd ents bre ,estt worn at ental ofT .{o)dir -or .U ,gairqe edt to mottoa edd tebas ,b1av e-O-L ;nottisog [artatro sti eedoser tk Itt aottrfover exo yLletemtxorgqqs wosd exret tr egtsl edt to tnomovom altAT tebas mort tuo miq eorretretet edt amrst tases ot tevel tact awolla bra revel teatmos odd et tostmoo qmef eft ymso edt otmo doad qorh 8928800 StTotereds satntsw edt dae .-fetord bt teen ontal edt to tnemevom brewioad eT edt uaxtticta otq somerstretat edt rd beqyota motstinos s dove .reref tostmoo edt to Bae w(@)dr eutt mt mvode at etre; edt to eusierse eft tadt tebro al

eit {tins mwob bled ed ton beer vex amretet

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

indication mechanism has assumed the start- ing position, a pawl, P, has been provided, This pawl drops into a notch, N, cut in the release lever, when the lever is in the re- lease or full-left position. The release le- ver is threrfore held in the extreme left position, after it has once assumed that po- sition, by the pawl. The carriage return key need, therefore, not be held down in order that the release lever maintain its position. The pewl is thrown out of the notch, and the lever freed, by a stud or trip pin on the lower face of the large gear. This stud is so placed that just as the lerge gear reach- es its starting position, the stud strikes the pawl and trips it out of the notch. The release rod then returns to its normal posi-

tion.

We have now completed the

66

30

YHIAAOLLIGT QUITUIAL FO MATeYe MUAAHOM HHT

-trete edt fomusss ead metasdoom motisotiat Seblvorg aoed esd .f ,f[waq 8s ,sotttaogd ant est at tzo .% ,dotom a otat ecoth [weq etdt ~ay edt af et revel sdi modw ,revel ossolet -9f sesefer edT .motttecq ttel-f[int to sasel tel emetixs edd at Sled erotretdd ef tev -og tad? Bemyese somo cad tt retts ,aottteog yet muster ensitras efT .Iweq edt yd ,nottte tefro at amwob Sfer ed ton ,srotetred? ,boom emottiaoqg ett atetntem tevel sesofor edt tant edt Bas ,dotor odd to tuo mwordd at Iweq od? edit mo mtg git? ro fute e yd ,boert revel

eb bota etd? .tsee egtel ent to esst rewol -foser tees satel edt es tent vedd fesriq oa eexiuve bute ett ,moktteoq sattrate ett Bo ed? .doton sft to tgo tL aqixt base fweq oxi? -teog famitor ett ot emintsy mott bow oseefer

Mot?

edt betefqmos wor svat oe”

67

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

description of the Morkrum perforator, and will next take up a discussion of the dis- tribution system, the general theory of which

was developed in the Introduction.

Vs

YUTALPEITT OUITMIAL FO METeYe MUSAROM AAT

baa ,totetotreg morvro! edd to sottqitceeb ~efh.edit to anoteenoerth s qu eat tren [iiw doldw to yroedd L[etoenmer oft ,meteaye nottudizt

exolioubortal edt at beqefeveh eaw

68

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY Part III- The Distribution System. GENERAL. The distribution

system of the Morkrum System of Printing Telegraphy is the same as that of the last introductory system, viz., that of Fig. 6. There are a number of auxiliary devices add- ed to assist in operation, but the general plan and theory are identical with the plan and theory of Fig. 6. For communication in both directions, the apparatus of Fig. 6 must be in duplicate at the two stations; that is, each station must have both transmitting and receiving equipment. It has been found advan- tageous, therefore, to mount the transmitting and receiving disks of one station, together with their auxiliary equipment, on one base; the complete set of apparatus is called the é@istributor. By this means, compact construc- tion is obtained, and both receiving and trans-

mitting brush arms may be driven by a single

638

YEIAHPALST OWITHIAL TO MeTeYe MUASHOM BHT smeteye noltudixtetd ed? -III tral sottudixntels edT .TASHMED

eottats? to matey? mrdroM edd to meteye tasl edd to ted? ee emse oft ef yigargefeT .9 .2tl to tad? ,..atv .meteye yrotonhoriat -bbe eestveb yietlixse to tedmux @ era stedT fetonen oft tud ,notieteqo at teteee ot be mefg edt dtiw [sottmeht ete yroedd bas nelq oft gotteotasamoo trol .d .gtt to yroodt Sas gesm 39 .zit to extatsqqs eft ,anoltoerth dtod eet teadd senottsate owt edt ta etasotiqnh at ed Bue untttioenert dtod evad tenm motista doae -sevbs Savot need sad tl .tmemqiops antvieset gaittiinenert eft tnvom ot ,eroteted? ,asoenst rettexzot ,soltiate emo to avtath umtvteoer haa ;oasd emo no ,tmomalope yratiixses tledt diiw est hefiIso ef antereqgs to tes etelqnoo eft -ovitesco tosqmoo ,emsaem efdt yt .rotedixtatd -erert Bae univisoet dtod Sne ,hentstdo et mott efaste s yd mevith od yer eorre deord satition

THE MORKRUM SYSTEM OF PRINTING TELEGRAPEY

electric motor.

In the following description of the distributor, the general action of the apparatus will be explained with the aid of rough sketches; the accompanying photographs of the actual machine show the details of

construction. The general order of treatment

will follow the path of a current pulse through

the machine.

The general layout of the dis- tributor is presented in Fig. 15, which is a top or plan veiw of the apparatus. The figure shows the positions of the various parts, but is schematic as far as their construction is concerned.

THE MOTOR. The motor, which drives both brush arms and the tape feed mech- anism, is a 1/10 H.P., 1800 R.P.M., 110 volt,

D.C., series machine, manufactured by the Gen-

69

ea

YHTAAOST IAT DULTMIAT TO METeYe MUSAAOM FHT

.rotom ofrtoele

mottqttoash snlbwoffot ext alt edt to mottos [srores sft ,rotudivters eit to to Bts odt Attw hentel[qxe ed Iflw evtersecs adqataotodg aniynsqmosos edt yseiotete dayot to eftstei efit wode enttosm {aftoa ont To tromtaerd to tobro L[atetes efT .notvourtenoce siaguvorsit eafog taorrso a to dtaq est wolflot [fiw -enidoan eft

-eth eft to tuoyesl [srenen odT gs et ito betw .OL .giT at betneeerqg ef rotudiat exsett efi? .entsrecaes oft to wlev malg ro got tad vetreg esotrav oft to exoltteog edt ewode elt nottorrtenoo ttedt es rst ee ottamoroe et . besrranso9

dotdw ,rotod efT .HOTOM HHT -foem fost eqet edt bre emrs deord tod sevirh effov OIL , M208 008L, .T.H OL\£ Bs et “metas

-sef ect yd berutostunam ,extitoam celtod ,.0.0

70

THE MORERUM SYSTEM OF PRINTING TELEGRAPHY

eral Electric Company.

The speed regulating device, shown at the left of the motor, is applied, since it is essential that the machine run at constant speed. As is indicated, the de- vice is merely a fly-ball governor, driven by the motor, and arranged to open a contact when the spead becomes excessive. The con- tact is placed between the motor and the source of current supply; across the contact is shunt- ed a 1000-ohm resistance. If the motor speeds up, the governor opens the contact, and there- by places the 1000-ohm resistance between the motor and line. The motor therefore slows down until the contact closes again, snd shunts the resistance, By means of this governor, large changes may be made in the load or ap- plied voltage without any great effect on the spped of the motor.

In Fig. 16 is given a detailed

oT

YHIAROEIET DLITWIAG TO METeYe NUSIHOM FHT

eUnsqaod olrtoelt [ere

,eolvel natiefinseer beogs edAT botiqqs at ,tovom edt to tief oft ta mwore sox ontdosm oft tedt fatincase et ti eonte -95 eft ,feotsotint et eA .ioedqe tuatenco ta mevirh ,iostevog I[f[sd-yft eae Ylerem et esty tostncs 8 aeqo ot bentesta Bae ,totom sft yd ~09 edT .esviteesexes semooed kseqea. edt norlw eerroe edd bas rotom edt meewted Beseltq at toat -toode ef teatmoo eft evorcos 3ylqque terry to ebeeqa totom eft tI .eonsteteet mio-000L & be -erTeit bas ,tostmoo edt anego tomrevog edt .ax edd seewied eometates t mico-000f edt eooaltaq yd ewola exrotereds szotom odT .enif Bae sotom etenda foe ,otssae eeseofs teatnos eft Lhitanw mob ,tomtevern efit to exsem Yl .eomateteor ont -q@ tO Beol oft mt sham ed yam cosnado esrel eit mo toette teeta yee tyodtiw enstfLory Setic etotom edt to beqge

Beltetedh s sevis et 3f .2tT mI

THE MORKRUM SYSTEM OF PRINTING TELEBRAPHY

veiw of the governor. The mechanism is sup- ported in a steel "0" frame. This frame is attached to the motor by bolts, as shown. The operation of the governor is apparent from Fig. 16.

THE TAPE CONTACTS. The tape contact mechanism is located at the lower right-hend corner of the machine. This mech- anism performs the same function as it did in the introductory system of Fig. 6; that is, it controls the relay pole changers,being it- self controlled by the paper tape.

The tape contact pins are five in number, and are held in a vertical plane, as shown in Fig. 17. Hach pin is held ina pin-holder, which is a small,round, brass disk. The pin runs through the disk edgeways, and is fuxed to the disk by a set screw. A bearing hole is bored through the disk from

71

iv

YHTARSELET DUITULAT TO MATeYe MURAIOM ART

-qvea ef metosdoem ef? .1omrevog edd to whov et emext efdT ,omext "O" Leete se ot betrog sawode e& ,etlod yd rotom efit of bertostis tnersags et ronrevo”_ eft to gcottersre sil OL sgtt mort

eqast efT, .cTOATHOO EZAT THT tewol edt te betsoof ef metnerioom tostmoo ~-fioom efdT .sntdosm oft to renreo hited=tiatt mt Bb tk es molttonst emse sot aemrotreq metas et tedd 73 .gfT too meteye yrofesbortat ott -tf golted,erosmedo efog yeafer edt efortcos tt eoqat teqeq eft yd bhelfortroo tlee

erft ere ento toninoo ecat of? eeralq L[eottixevy 8 mt Bled ets. bor ,tedmen rt gmt Led et otq dos® .“f watt nt awode as -eeatd ,boevor,[isme s et doldw )tebfodt-atq -6yavenhe selkh oft Aywordd anor mtg edT .ofeatd &£ .weroe’ tee a yd fetb eft ot hexvt et bre mort Heth est davordd bexod et eLod antrecd

THE MORERUM SYSTEM OF PRINTING TELEGRAPHY

face to face, but considerably off center. All five of the pin holders are mounted on

@ vertical stud rising from the base. The tape-ends of the pins rest against a metal plate called the tape shield. The opposite ends of the pins are fitted with contact points, which are alligned with contact screws. The serews are supported by an insulating bracket, which, in turn, is supported from the base. This bracket insulates the pins from the base and from each other, For ease and compactness of construction, the contact pins are alternately long and short; the con- tact screws are correspondingly staggered.

By this construction, more room for lock nuts on the screws is provided than would be if the screws were all mounted in a single ver- tical row. The contacts between the pins and

screws are normally held closed by the springs,

72

st

YHITARVELIET OUITAYIAI TO METeYe MUSIAOM ART

etetmoo tto yidsrehteroce tud.,eomt ot sost

no hetavom era eteobfod mty edt to evtt ILA eft .casd eft mort anteta bute Lfaettrey s fatem 2 tentess teet axtq edt to 2ebne-eqst etteoqqo eft .bfeltdte eqat edt hellse staid tostnros dtiv hbediit ere extq edt to ehse .eworoe tostaoo dtiv homelifa eta doitdw ,etntog guitelverct na yd bettoggrva ets avertoa oat mort hetroqqve ef ,arst at ,dotiw.,textoard amiq edd eetelsant texoetd etdl .eead edt sess Tot ,~tedto dese mort Sas sesd eit mort tostaos edt ,sottouytenos to seentoaqmoe bas “08 ott :ttode bas gnol yfetsaret{[s ere entq Seotegsets ywlantiaogesrros ere aweroe tost sda Zool tot moor siom ,woltesrtemos etdy ¢& tL od Sieow cedt bobitvotq et everoe edt mo -itev efgnte 6s at betmvom [fe etew ewetoe odd Saxe entq eit neowted etoastaoo odT .wot Leolt

-egaiuge odd yd Asaclo SLod yffsemrom sts ewetoe

THE MORKRUM SYSTEM OF PRINTING TELEGRAPEY

S, as indicsted,

In the operation of the tape- contact mechanism, the tape runs between the ends of the pins and the tape shield, so that the pins are lifted away from the shield a small amount. This displacement of the pins, though very small, is multiplied by the lever action of the pins and pin-holders to such an extent that it is sufficient to open the cen- tacts. When the perforations in the tape oc- cur. the ends of the pins, under the action of the springs, S, drop through the holes and close their respective contacts.

THE TAPE PEED. The tape-feed mechanism is also apparent from Fig. 17. The feed-wheel consists of a brass disk, fitted with short, steel, wire teeth; the disk is fixed to the lower end of a vertical shaft called the feed shaft. The wheel and shaft

73

éYv

YHTAHOS INT OAITUIAT TO MATeYe MUHAAOM FHT

ehbeteothat ca ,f

-eqet edt to sokteteqo edt at edt meewted enut eqat eft ,metnedoom voatnoo tadt oa ,Bfetde east oft base entq ott To abso & bletta odd mort yews Hbettil ere antq edt ~ematg edt to treemenosiqeltbh eidT .davome [fame tevel edt yd hbetiqtifom ef ,[feme yiev davodt me ose ot etebfod-nrtq Bae entq oft to nottor -xoo ent meco of tnetotttre et ti tadt tretxe -90 eqed edt at emotdsrotreq edd med? .atost aofies edd tobag vache edfy to ebme sdt .1r0 Sas esfod efit asvordt qord .2 ,agninqe ont to eBtostnoo evitoeqeser treit seols

beet-eqst eff .CEEY STAT FHT edt VE entt wort trersqys oefe ef metnadoom Hhestlt ,Heth aserd eg to etetenmos L[eedw-boeet et vetbh edt jdteet extw ,feete , trode dttw ttere [settrey 8 te bue tewol ett ot Sexit tIiade bas feerw of? .ttade Soot edt helleo —

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

are located on the opposite side of the tape shield from the contact pins and tape, but the edge of the wheel projects a slight dis- tance through a slot in the shield, and is thereby enabled to engage the holes of the tape.

The upper end of the verti- eal shaft carries a worm wheel which engages @ worm on a horizontal transmission shaft from the motor. The worm drive, as shown, is enclosed in a gear-box. The gear-box cast- ing extends downward to form a casing or col- lar bearing for the vertical feed shaft; it extends to either side to form a sleeve about the transmission shaft. By this arrangement, the vertical shaft and feed-wheel are sus- pended from the transmissi6n shaft. The low- er end of the vertical shaft is normally held against a stop at the bottom of the tape shield

74

SY

YHTASDRIAT DPUITUIRI TO MITEYe MUAAAOM TAT

eqat edt to site ettaogqe eft mo hetsool ots tud ,eqst Baa satq tostooo eft mort Bbleltide -etb tdsifea e etoetorq Loedw exit to sahe odt st bas .,ifetie sdt ot tole #2 dyvotst soonest edt to eefod sit egeane ot befdane yYdetedt eoqat

-titev oft to Bue reqqr edAT eengane dotdw feedw mtow 2 sefitae ttede. [a0 ditede moltsetmanar? [atmosirod 8 mo mrow 8 ecwors aes ,evinb mxrow eft .rotom odd mort -faso xed-tseg efT .xod-tseg 2 ot beeoLlore ef -[oo to gatess sg crot ot Stawmvob sinetxe ant tt gdtede beet Isoldtevy edd tot gritsed tel suods eveela #2 mrot ot ebtea redtie of sbretxe etherognert2 efdt ya ,ttate oofesinanerd ent -ese ets L[eedw-heet fre ttade [eoitrev oft -wol of? .ttete cofeetmensrs eft mort bobaeq Brod yifeuron ef ttade [solttrev eit to bre t6

Sfetds eqst oft to mottod edt ts qotea 2 tentazs

75

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

by a spring, so that the feed-wheel projects through the slot in the tape shield.

An attachment which aids in the threading of the tape under the tape con- tact pins is also shown in Fig. 17. This de- vice serves to pull all the contact pins a- way from the shield, and at the same time, withdraw the feed-wheel from its slot. When the parts are in this position, the tape may easily be threaded under the pins. Upon their Telease, the contact pins again rest on the tape, and the feed-wheel engages the feed holes.

The attachment is operated by the movement of the lever, L, of Fig. 17. The movement of this lever, through the cam, C, pushes the lower end of the feed-shaft and the feed-wheel away from the shield.

The movement of the lever, L,

ar

YHTAROSIET DUITUIRI TO MATeYe MUAAHOM SHT

etoetotq Leedw-hbeet eft tedt of ,aacizrqe s yd ~bletse eqet edt at tele edt Aguordt

ot ebts dotdw dnomiostis aA -moo eget edt tebas eget eft to gnthserdt edd “96 eatxT .TI .att ot owode oefs et enxnta toast -s emiq tostaos eis [fe [f{sq ot eavres asotr .omit emae edt ts fos ,bfetda edt mort yew med” ,tofea atl most Leecweboet oft warbditiw ys eqat edd ,cottteod sidt mt ers eatraq ont attedt moqU .ertq edd robau fSebsexrdt ed yitese edt oo test miegs emtq toextaoo odd ,seselet best edt sepeanme Leedw-Seet edt Bas ,ogst : selon

Beteatege et taomdoaetia odT TL .gtt to ,< ,sevel edt to tmemevom oft yd emiso oft dasordd ,r9evel sidt to tmemevom adT dtede-heet eft to bas szewol efit eotteng ,9 -bfetdea edd mort yevs Lostiweheet odd bas

I ,tevel odt to tmenevom oft

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

also raises the contact pins away from the tape shield, through the agency of another lever. By referring to Fig. 17, we see that between tape pins #3 and #4, there is a free space, due to the fact that the row of feed holes occurs in this space, A bell crank is mounted with the pin-holders between holders #3 and #4, the bearing being at the elbow of the crank. One end of the crank extends along the pins a short distance, and terminates in & vertical cross-rod. The cross-rod extends completely across the row of pins. The other end of the erank is connected to the lever, L.

Thus, when the lever, L, is moved to the right, it not only withdraws the feed-wheel from the tape shield, but also lifts all the pins away from the shield. With the parts in these positions, the tape may

76

hy

*

YELAADEINT DHITHIAL 4O MATEY MUAASOM THT

ety mort yawe entq torstooo oft aseter celfs softone to voness oft darordt ,ffetda scet tet ese ow .TL og ot antaseter yi .tevel eert s et otedt . Be bus 8) enta eqet neowted Beet to wor eft tadt fo2et efit ot ob ,cosae ‘et Maero Ifed A .eoaqga etdt at exsooo eefod eresffod soawted sexehfod-atq ent dtiw betnvom to wodfe edt te gnted art+sed ent ,34 Boe 8% gasofs ebaetxe wneto eit to bue emo .xnmetro oft ct eetaniorvet fea ,eenateth trode s antq sift ebsetxe bor-aeoro edT .Sor-saoros {serttrey a tedvo eff .anta to wor eft eecros ¢istefqmos etevel eft ot hetoommon at anero ent to bao ol

eft ,f ,tevel edt medw ,endT eit awatbatiw yf[oo ton tt ,tdetr eit ot bevom coals tud ,bfetde eqat eft mort Leedw-best a¢2W .bLetde eft moxt yeve eat oft [fe etttl yam eqet eit ,encotttsoqg oeedt at etrsq edd

‘

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

be easily threaded under the pins. When the hand lever, L, is moved back to its normal position, the pins and feed-wheel also re- turn to their original positions; they per- form this movement under the action of their return springs.

The tape contact and feeding mechanism just deseribed is mounted on a brass plate, fastened to the main base; hence, the entire mechanism may be easily replaced in case repairs are to be made upon it.

To facilitate such replace- ments, the worm shaft of the tape-feed is con- nected to the main shaft from the motor through the coupling, D, of Fig. 17. This coupling con- sists of two steel disks, one on each shaft. The two disks are faced together and connect- ed, near their edges, by a single pin. Such a

coupling furnishes no impedance to the removal

77

TY

YHIARLDEIET DUITVIAI FO METEY2 MUSAHOM FHT

eisv condW .entq ent rebsaw bobsordtd yitese od Senros ett ot #wosd fevom ef .1 ,tevel Bred -et osfs fesdw-iset bae entq et ,aolttteoq -teq yest ;enoliteoq [antaito tredt od arst ttedt to ncottes eid tebas taomevom aidtd arot -cunizqe arstet

amibeet Sae testsoo eqet e:iT eeetd #2 so betasom st hodtroseb tart melaadoom efit ,soned ;eaad ntem elt ot Semetest ,etely ot BéSRTGét vitesse od yam meteaoom ov tice ott soqs efem ed ot ets attsqet esse

-soeiaer dota etstiitesst of -xoo at beet-eqset edt to ttade mtow edt ,elnem dasordt rotom eit mort ttade atem edt of betoor -n09 nat{quos etdT .VI weit to .f ,antiquoo odd ettade dose no ero ,eteth [eetea owt to eteate -tsonmmoo bas tettesot Boost ets etetbh owt edT e dou® satq ofgate 8 yd ,eonbe tiedt ween . fs

fevomer eft of comsheqmt om sedatarst gatiqsuoeos

78

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

of the mechanisn.

THE TRANSMISSION SHAFT. The transmission for the tape-feed mechanism is shown in Fig. 18. As indicated, the trans- mission shaft is supported in four bearings, B; one is on @ bracket near the motor, the second by the coupling, and the last two on either side of the worm drive of the feed- wheel. These latter two bearings are a part of the bracket whieh supports the tape shield. The general plan of transmission is this; the motor, through a gear train, drives the gear, G; this gear, throughsa clutch, drives the transmission shaft, which, in turn, drives the feed-wheel. None of the transmission parts need further comment with the exception of the elutch. The cluteh forms a part of an automatic stop system which will now be dis-

cussed,

et

YHIARDAIAT DUITUIST FO METCYe MULAAOM SET

eustnxasoom edt To

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beeen

719

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

THE AUTOMATIC STOP. It has been found necessary to apply an automatic stop or control device to the tape-feed mech- anism. When this device is omitted, diffi- culties arise when the perforator operator does not work fast enough to supply the dis- tributor with tape. The tape tears between the two machines, or else the distributor feed tears the feed holes out of the tape.

It is with the idea of overcoming this dif- ficulty that the manufacturer adds the auto- matic stop.

The general plan of the de- vice is this: before entering the tape feed of the distributor, the tape loops over a small lever. This lever carries a contact point at its opposite end; a second point is fixed to the base. The opening and elosing of the contact controls a magnet called the

er

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ent belf2eo towrpgem s afortnoo toadnoo ent to

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

cut-out magnet, which, in turn, controls the feed clutch in the transmission shaft. Ordin- earily, the tape between the perforator and distributor hangs loosely and exerts no pull on the lever; but if the tape tightens up, as it will when the perforator is working Slower than the distributor, it pulls on the lever and opens the contact. The solenoid is de-energized and opens the clutch. The tape feed is thereby stopped before the tape is torn. When the tape again becomes loose, the lever is released, the contact closes, the clutch solenoid is energized, and the clutch re-engages, so that the tape feed pro- eeeds as before.

The automatic stop as actually applied to the mohine is shown in Fig. 18(a)

and (b). The gear, G, is made in one piece

08

YHILADTIAT PHITHIAT FO MUTeYe MUEAAOM ANT

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81

THE MORKRUM SYSTEM OF PRINTING TRLEGRAPHY

with the sleeve, S', and the disk, A; the sleeve makes a bearing fit with the trans- mission shaft. The disk, A, constitutes a part of the clutch. When the elutch is en- gaged, the gear, G, and the shaft turn in unison; when the clutch is disengaged, the gear, G, the sleeve, 3, and the disk, A, turn idly upon the shaft, whereas the shaft remains stationary.

The detailed construction of the cluteh is shown in Fig. 18(a) and (b). On the transmission shaft is mounted the car- rier, B, which carries the elutech dog, D. A spring, S, holds the dog against the edge of the disk, A. In the edge of A is a small notch, N, and at the end of the dog is a tooth which engages the notch. It will be seen, therefore, that as long as the dog, D, bears against the edge of the disk, A, the

£8

YHIAAOTIFT PUITMIAT TO METeYe MUASAOM FHT

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edy ,4 ,xeth oft to exis oft tentens ereed

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

Gluteh is engaged. The clutch is disengaged when the dog, D, is held away from the disk, A.

The tripping mechanism for

disengaging the clutch is also shown in Figs.

18. On the base, and near the ecluteh, is lo- cated the cluteh solenoid, M. The solenoid has an armature, pivoted at the lower end, which carries a stop pin, P. Ordinarily, the solenoid is energized, and therefore holds its armature away from the clutch. However, when the control contact is opened by the tightening of the tape, the solenoid is de- energized, and its armature is drawn away by a spring. This armature movement thrusts the

stop pin, P, into the path of the dog, D, so

that the dog strikes the pin. The dog is trip-

ped out of the noteh, and the clutch is dis-

engaged.

82

Ce are

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YHIZAROAIAT DUITHIAL GO METeYe MUAAAHOM FHT

hegaegnesth vi dot#io efT .begegme et dotslo -x8ib edt. mort yewa blod at .C ,gob ext aedw oA

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edegsygre

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

Means are provided for the holéing of the dog, D, away from the disk,

A, On the transmitting shaft, and beside the carrier, B, is mounted a disk, C. This disk conteins a wide shallow V-notch in its edge.

A lever, T, is pivoted at one end to the

base plate of the machine; the upper end bears against the cam, C, under the action of a spring. The end of the lever is so shaped as to fit in the notch of the disk, C.

In the operation of the device, the shaft and the disk, C, ordinarily revolve so fast that the lever has not time to drop into the noteh of the aH otro wa ow the notch is so shallow that should the lever drop into it, the lever could not hold the disk against the driving force of the shaft, but would be raised out of the noteh as the disk turned.

When the stop pin, P, trips out the dog, D,

83

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YHTASSEIAT DLITULAT TO Maeve MUAAHOM FHT

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THE MORERUM SYSTEM OF PRINTING TELEGRAPHY

the momentum of the carrier causes the parts to assume to position of Fig. 18(b). The dog, D, is now well clear of the disk, but the spring on D tends to rotate the carrier back- ward until the dog drags on the disk, 4A. How- ever, the notch on the disk, C, is cut so that just as the parts come to rest in the position of Fig. 18(b), the notch in C stops under the end of the lever, T. The end of the lever drops into the notch and locks the parts in position. Hence, the dog, D, is kept elear of the disk, A.

When the dog, D, is released by the stop pin, P, it drops onto the revolv- ing disk, 4, As the notch in A passes under the dog, the dog drops into the notch, and the clutch is thereby re-engaged. The notch in the cam, C, is shallow, so that the lever

easily rises out of the notch and rides on

84

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YETAFDAIAT DAITUICL TO METEYA MUMIAOM ANT

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mo aebit Bree fotom eft to dro seeit yitero

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the edge of the disk, thereby leaving the entire clutch free to rotate.

THE CUT-OUT. A so-called cut- out mechanism is also shown in Figs. 18. The purpose of the device is to operate a relay, which operation eauses both front and back contacts of the pole changer relays (identi- cal with the pole changer relays of Fig. 6) to be connected to the positive side of the battery. Hence, when the device operates, on- ly positive line impulses are sent out; this condition is the same as when the "rub out" signal is given, which signal consists of all positive intervals, and it will be remember- ed that the printer does not respond to such

signals. When the tape feed stops for any cause, the cut-out device operates, so that the printer is kept inoperetive. If it were not for this device, the printer would print

85

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“YHIARVAIET DUITHIAL FO METEYS MUSAOM FET

odd astvsel ydeteds ,deth edt to eahe aft

-otator ot sett dotsfo ertine -txo Belfse-o8 A .TUO-TUD SHT

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tatrq Bluow tetaita edt ,eotveb etdt tot tor

THE MORKRUM SYSTEM OF PRINTING TRIEGRAPHY

over and over again whatever character hap- pened to be in the tape contact mechanism when the tape feed stopped.

The details of this device are also shown in Figs. 18. On the feed shaft is mounted a disk, K, containing a wide noteh, as shown; against the disk bears the lever, H, pivoted at its lower end, and held against the disk by a spring as shown. The lever, H, carries the movable point of the contact, J. When the lever bears against the edge of the disk, the contact is held o- pen, but if the lever drops into the notch, the contact is closed. The details of the cut-out relay and of the eleetrical connec- tions will be given later. The cam, K, is so placed on the feed shaft that when the shaft stops and is held by the disk ¢ and its lev- er, the notch in K will lie under the end of

38 YETAMPRIGT QUITMIRI TO MaTeye MUATAOM eHT

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87

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the lever, H; hence, during this time of stop, the printer will remain inoperative. When the feed shaft is revolving at its usual speed, the lever, H, does not have time tordrop in- to the notch.

THE TRANSMITTING DISK, Next in the order of treatment comes the trans- mitting disk and brush arm. The disk is lo- eated behind the tape-feed mechanism, as is indicated in the general plan of Fig. 15.

The driving of the brush arm by the motor is accomplished through the gear train and main shaft, as shown in Fig. 15, the main shaft carrying the brush arm. The main shaft is supported at its ends in bear- ings, B, one being on a bracket near the mot- or, and the other being on the bracket which supports the transmitting disk. The shaft passes through a large hole in the middle of

v8

YETAROSIET DUTTMIAT GO MATEYe MUAXHOM THT

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88

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the disk to the bearing at the back side of the disk. The bearing support is shown in Fig. 19.

The transmitting disk is of fiber, about two and one-half inches in dia- meter, and is supported from the base by a bracket (see Fig. 19). The disk carries eight brass contact buttons, set flush with the face of the disk. Connection is made to the buttons through leads at the back.

The functions of the eight buttons are indicated in Fig. 15. There are the five code buttons, 1, 2, 3, 4, and 5,

a lamp button, L, and the two synchronizing buttons, the first positive: and the second negative. The functions of the eode buttons have already been explained. The lamp but- ton is used in the operation of a signal lamp, by which the receiving station signals the

88

YHIATOAIET DUITAIRI TO MATeYS MUMAHOM AAT

to ebts dtosd oft ts aoirsed eft of Meth ont at mwode et trogqse antrsed efT .xeth oft oCI alt

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89

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

transmitting station or vice versa. The syn- chronizing buttons are used in keeping the transmitting brush arm at’ one station and the receiving brush arm at the other station in step; the synchronizing system will be ex- plained a little later. It suffices to say here that the positive button is connected perm@nently to the positive side of the bat- tery, whereas the negative button is connect- ed permanently to the negative side of the battery.

The brush arm and brush are mounted on the main sheft on an insulating bushing. The brush arm is of brass, whereas the brush is a copper strip, bent into a "U"; one end is attached to the brush, the other trailing over the disk. The brush arm also carries a felt wiper, as shown in Fig.

19, which wipes over the disk and keeps it

28

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df aqesd faa Asth eft t9v0 eeqtw dotdw ,er

THE MORKRUM SYSTEM OF PRINTING TLEGRAPHY

free from dirt.

Contect is made with the brush arm by a wire brush, consisting of a number of vertical wires. This second brush bears against the hub of the brush arm. The support of the brush in its bracket is clearly shown in Fig. 19.

THE POLE CHANGER RELAYS. Con- sidering the path of a current impulse through the apparatus as our general order of treat- ment of the subject, we find that the pole changer relays come next in order. The five pole changer relays, whose function is the same as in Fig. 6, are located in a row at the upper left hand corner of the distribu- tor base (see Fig, 15). In addition to the five instruments mentioned, there is an addi- tional one, the cut-out relay, whose function

is to connect both front and back contacts of

90

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YHLAAOALITT DAITMIAI TO METeYS MUSAAOM ERT

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91

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

the others to the positive side of the bat- tery. The sixth pole changer relay is simi- lar in construction to the others.

A detailed view of one of the pole changer relays is presented in Fig. 20. The solenoid, as mounted on the distrib- utor is vertieal; it is fitted with strap i- ron pole pieces, Py and Po, The bottom pole piece, Po, is prolonged and bent up along the front of the eoil; the pole piece extends about half way up the coil. The armature is of the same stock as the pole pieces, and is hinged to the armature as shown. The arma- ture carries the eontact lever, C, which is insulated from the armature by a sheet of fiber. A bracket is attached to the lower part of P2, runs up in front of the armature, and carries the fixed relay contacts, The

armature is normally kept against the back

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YHTARDALIAT HUITHIAG FO MATeYe MUAAHOM FHT

-ted edt to ebte evititeor edt ot etedito out -Imte et yalsr toansdo slog dixts eit .yret earedto edt of molttomurtenoos af taf

to emo to wety hefieteb A | ai at Setasastq at aysfer tegmaio elog sat -dixttetS edt so hetnwom ae ,btomefoe eT .08 -t qatte dtitw betstit ef tt :fsottrey et tets efog mottod eT of Boe -T ,se0efq slog sot anoles qu taed bas besnolorq at .of ,esety ebmetxe esetq efog eft ;f[too ext to taort edt et aruteamrs ofdT .ftoo edt qu yaw tfed treds st bas ,eeo9tq sloq adt an woota emse edt to -anrs edT .myroie es stytamrs oft of boantd at doidw .5 ,tevrelt sostaos edd eetrieo erut to teste s yd otutemre odd mort bSetelveant

- towol eft ot bedoetta af tedostd A .tedtt sistemas ext to tnott at qu east ,si to traq edt ,atostnoo yefet bextt edt astiures bas wosd edt tentesse tqed yifesrom et etstearrs

92 THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

eontact by the flat steel spring, 5S.

When the solenoid is ener- gized, the upper part of the armature is drawn toward the upper pole piece, Py, which movement closes the front relay contact. When the solenoid is de-energized, the arma- ture, under the action of the spring, 5S, re- turns to its original position.

In Fig. 20(a) is shown the conventional symbol used for such a relay in wiring diagrams.

Next in order of discussion occurs the main-line pole changer; however, we will omit this diseussion for a time, and hext consider the receiving apparatus.

THE RECEIVER DISK. The receiver disk and brush arm are located behind the trans- mitter disk, as is illustreted in Fig. 15. The

construction and mounting of the disk is, in

ge YHIASOTIAT OPULTHIAI TO MATeYa MUAAAOM FHT

oc ,amtinqe [sete talt ed? yd toataos

-tece et btonsfoe edt modi et erstemra edt to trag teqgs edd ,bests dotdw .ft ,seetg sfoq r9eqgs edt biswot aweth etostmos ysfeor trort sdt sesolo Saomevom -emts edt ,fesiateme-e5 2? Stodmefea edt ced -et ,© ,aoivqe edt to actios edt tebas ,esrst ecottisoq [entatto att ot satus

edd awode at (8)08 .gtT al ysfer s dowe tot fees Lodmaye I[saoitmavacs eamargsth antitw at

mofsesosth to tebto at txeH etavewon ;togdedo efog enti-xatam sit azsoco has ,emit s tot motesseath ealdst timo (fiw ew -eutstaqqs axtvieset odd tebteros trem

tevteoot edT .1eId AEVIZORR BHT ~enaty edt Batded Sotsool. ets mrs deord bos. aeth eqT .of .2ti ot beteattev[([t at eae ,weth retin at ,ef Heth edt to antinvom ae nottosstegos

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

general, the same as that of the transmit- ter disk. One difference in the two is that the receiver disk possesses one large but- ton at A, (see Fig. 15) instead of the two synehronizing buttons which the other pos-

sesses. The other difference is in the attach-

ment of the disk to the bracket. The receiv- er disk is attached to the bracket by thumb- screws if such a manner that after loosen- ing the thumb-screws, one may turn the en- tire disk through a small angle. The theory of such an adjustment was presented on page 30 ff. The disk has a scale marked on its edge, so that its angular movement can be gauged.

THE TRANSMISSION SHAFT. The driving of the receiving brush arm from the moter is accomplished through 4 main shaft,

carrying the brush arm, and a gear train, as

93

a J 2

YHITAADTIAT OMITUIAT TO MATeYe MULAHOM ANT

-timenett odt to tedt es omee edt ,I[stenep tadt et owt edt ot someteTtt& emO death ret -tud estal emo soeasseog Heth tevtesor aft owt edd to hbretemt (8£ .atf eee) ,A te mod -8og tedto sdt dotdw anottsd entstaordonye -dostis edt mt ef eemersttih radfo exT .asaaee -vieser ed? .tetoatd oft of Heth odt to trem -dandt yd teatosrd edt ot feroatis et wets +e -nsesoof tette tad? tenasm 2 dose &t swetos -te odt mut yam somo ,oworne-dandd oct act ‘yroodft ef? .efane [fame s darordd ast ert? ezsg mo betsecerq esw tmomtentis ce dove to ett xo heitsm eL[ses ae ead wath edT .Tt OF ed sso daemevom tafvgae ett tedt oe .eade Segrag

ef? .TUAHS WOLCEIMeMART MAT edt mout ora deotrd artvtesor edd To aaivits Stade afem s Asrordt fedet{qmooos st totom

es ,atertt tsex3 3 Sas ,area deord edd antyirss

94

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

was the case of the transmitter. The shaft

is supported on two bearings, one on a brack- et near the motor:and the other near the disk and on the disk bracket. The drive, however, from the motor to the brush arm is not direct, but is through a so-called synchronizing eluteh. This eluteh constitutes a part of

the equipment for keeping the receiver brush at one end of the line in synchronism with the transmitter brush at the opposite end of ‘the line. We will now consider the synehroni- zer, of which the elutch forms a part.

THE SYNCHRONIZER. The scheme of the synchronizing apparatus is as follows: The driving motors at the two ends of the line run at approximately the same speeds, but the receiver brush arm is geared to run & little faster than the transmitter arm. The funetion of the synchronizer is to retard the

$e

YETAHOITHT HAULTMIRT TO METeYa MUAAROM TET

ttefe edT .xottinemert eft To sage edt aew -tosrtd # m0 exc ,Banttssd owt mo Bbetroqqss at wet5 edt resem rtedtc edt Bue totom edt teem to etavewod ,ovixS oft .texontd oweth edt mo Sas ~toorTlth tom at mre deoxrd eft ot rotom edt mort giisinordenye heff{se-ce s dasordt et tod to ¢trsq s setutitenos detufo eidl .dotsle dastd tevteser edt antgoeyv rot tnemyispe edt dittw matnordooye at eatf edt to bas exo ta to bre etteogqo edt tea denxrd rettimsenert edt -tuordenye edt tobtanoo wom [f[tw ef enti eat ed1tsq 4 sorot dotsLo edt dotdw to ,.tes

emedoe eft .AESIMOAHOUYe SHT tewolfot as et estatecqs antaiaotdemye edd to edt to ehao owd sit ts erotom gaivisS edt -ebooege emse edt vieteamtxortqga ta aur oatl net ot betseg et mrs deaord tevteset oft tod eff .orre rettimenats edt nedd tetest eftti£ s eft hretexs ot alt rexinordenys edt to nottonnt

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

receiver brush at suitable intervals, so as te keep the receiver arm sensibly in step with the other. The occurrence of the cor- rection interval is governed by the relative positions of the two arms, so that whenever the receiver brush has attained a definite small angle of advance over the transmitter brush, a correction interval takes place, so that the receiver brush is drawn back into its proper position, This retardation of the receiver brush is accomplished by the syn- ehronizing mechenism, which is controlled by the two synchronizing pulses, the first negative and the second positive, which the transmitter brush sends out between susses- sive letters. The two synchronizing buttons were mentioned in the deseription of the

transmitter disk,

95

6e

YHLAHDAINT DUITHIAI TO METEeYS MUSNHOM THT

ee oe ,Sfavretat efLdattys tn demrd revisser gete at yidtenesa mre toviteser edt qeei ot -roo edt to sometrso90 ed? .1radto odd dtiw evitafer edd yd benrevog ef Lsvretat aolttost tovenoiw tait of ,amrs owt oft to amoltlaog etiniteh s bentsiia esd dautd tevteser edt tottimenasrt odd tevo sonsvd5s to elane [fame oa ,eostg setst [2vtetat sotteerrose 2 ,dartd otmt aoed swath st dasad tertecer ost tadt sit to motisitster atdT .motitacq reqotq att -aye edt ¢d bedetiqmooss at dewsrd tevisoer BSel{fortiace at dotdw ,metnsdoom gaistaotds tert? oft ,seetiuq antstaordomre owt edt yd edt dotdw ,evitteog broosa edt Sac evitsgen -eessaue ssowted tvo abmoe darrd vettimanrsrt anotiud antstnordemye owt edT .atettel ovte edt to mottetroceh eA? mt Serotinoem etow

xetb tett tomdart

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

A schematic view of the syn- ehronizing mechanism is presented in Fig. 21. This figure illustrates only the general principal underlying the system: certain mod- ifications are necessary before it can be used in actual operation. The cam mrked cor- reeting cam in Fig. 21 is mounted on the re- eoiver brush arm shaft. A contact arm bears against the cam, under spring tension, so that every revolution of the eam, the end of the lever drops into a notch in the cam face. This movement of the lever close the contact, which is in a circuit composed of the contact itself, the corrector megnet, the marking contact of the main line relay, local battery, and ground.

Suppose the transmitter sends out the negative synchronizing pulse; the

main line relay closes the mrking sontact.

96

ae

YEIAHPALAT OAITUIAI TO METeye MUAYAOM FHT

-mys edt toe weiv oltamedse A ofS .3tt at botmosetaq et metasdoem gatstmrords fatsoreg edt yino seterteni{[t atsatt atdt -~hom atstres :mevayea edt satyf[rebas [aqtontrq ed meo ti eroted yrsacsoem sta emottsoltt -ros beslran aso efl .cotistere L[eutor at boas -et edt go Setnvom ef [S .gtl at mae gattoer exsed mre tostnoo A .tisde oa deaurd tevteo es ,foisass gatiqe tebasr .msao edt tontags bre oft ,meo edt to nolttuforst yreve tsds mso edt at doton s otmt eqoth tevel edt to edt esofo revel edt to txomevem aidT .soat te Sesoqmon tiseotto gs at ei dotdw ,tostaooe teagan totoertes edd ,tLoatt tostnoe edt eysiet eatl atam edt to toetaoo gatitam silt ebasors bas ,yretiad L[sool

ehbooe tottiogaett edt esoqyse edt j;eefue antstnovstonve evitesen eft tro

etostsnoo antititean edt esaofo yeter eatf atsm

THE MORERUM SYSTEM OF PRINTING TELEGRAPHY

Such a condition is indicated in Fig. 21. Now the notch in the face of the correcting cam is so placed with reference to the re- ceiver brush arm that if the receiver arm is ahead of the transmitter arm, the synchroni- zing pulse will occur while the cam slot is under the end of the contact lever. At this time, therefore, the cam contact is closed, and the main line relay is on its marking contact; hence the corrector magnet is ener- gized, and applies a correction. The next pulse is positive, so that the corrector mag- net is immeidately de-energized by the open- ing of the relay contact. If the correction need be but slight, the corrector magnet may be de-enersized through the opening of the eam contact.

When the receiver brush is

in step with the other, the cam contact does not

9”

ve

YEGALMECAT DUITHMIAT TO METEYE MUSDION THT

~fS .3t% wt betsothst ef motttbmee s dove anttoerros edit to sort edt ct deter ent wel -et oft ct ooneretet cttw feoslfq of ef mao el mrs tevieset edd tt tedt ove dentd tevtes -trovrdomze eit ,axs tettimeansrt edt? to heeds et tole mee edt eftdw rose IIftw selsq gnats efdt 3A .rsvel tosinon eft to base edd rebar ,beeolo ef tostnoe meo eft ,etotstait ,omti giivives efi mo et yeler omti ntam oft bas -stene ef temganm totostros aft sened ;toetnoo txes efT .mottoerzros se seilaqgs base bests -pem totesetros edt tedt of ,evitteog ef seis -feqe edt yd bestaremne-e5 yletobtommt ef ten sottoerroo ett tI .toe2tnco yalor oft to ant yam vomgem tothexrco ed? ,triutle tnd ed heen edt to antaeqo eft tayordd hestorense-eh of evoesnoo mso

ef sastd tervteset edt cor

tom e006 tostanos meo ond ,tente edt Atiw qete at

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

close until after the synehronizing pulse has occurred, so that no correction is ap- plied,

As was previously stated, the scheme of Fig. 21 is not the one used in prac- tical operation, since it is necessary to mo- dify the control of the corrector magnet somewhat. However, before taking up these modifications, we will consider the synchron- izing elutch, by which the corrector magnet is enabled to retard the receiver brush arm,

The synchronizing cluteh is shown in Fig, 22. The motor drives the re- eeiver shaft through a worm on the the motor shaft and a worm on the receiver shaft. The worm-wheel, and a gear, A, of Fig. 22, are in one piece together with the connecting Sleeve. The sleeve is bored to make a bearing

fit with the shaft, but is not fixed to the

98

YHIAADS TET DUITUIRL TO METEYG MUSLIOM HHT

eafogq artstaotdonye edd retts I[ittar esolo -qs ef motseertroo om tedd of ,berrsoco ead borig

eft ,betate ylevotvergq asw ef -orrq mt Beas eno ext tom ef IS .att to emeifos -om ov yrseeessen et tt esata ,mottetsqo Iseltt tengam totoerios edi to L[ortmoo edd YIEh eeedt qu satvet etoted ,tevewoH .tadwermoe -sordonyea eft toftanoo [[tw ew ,enottsotttbom Fores cofpertoe eit dotdw yd ,fotwle antst ets desid sevtecer add breatet of boefdane et

et dotulo antstnordonye eT -er oft sevith totom eft .SS watt at nwode totom eft edt mo arrow & duvordt ttede tevtes emt .ttade tevtesot edt mo mrow s bas ttede ere ,SS .ptt to ,A .teea © Bae , feedw-oiow gattvoonnos edt ditw sedterot esetq eno at anttsed 2 esa o¢ berod et eveela eT ,ovoele

edt ot Bextt tom et tud ,¢tede edt dtiw tit

99

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

shaft. To the brush arm shaft is attched the earrier, B, which carries the pinion, P, meshing with the gear, A, and the pinion, Q, meshing with the pinion, P, A star-wheel is mounted with the pinion, Q, and a jockey rol- ler bears against it, under the action of a spring, 3S. By this arrangement, as long as the jockey roller holds the star-wheel lock- ed in position, the carrier, B, the shaft, and the driving gears, A, and C, all revolve together. If however, the star-wheel is turn- ed, the two pinions, Q and FP, are turned,

and the carrier, B, rotates with respect to the gear, A, and hence with respect to the driving motor. Whether the brush arm is ad- vaneed or retarded, with respect to the moter, depends upon the direction is which the star- wheel is turned.

Below the elutch is the cor-

ee

YHTAHDELET OUITMIAI TO MATCYe MUSAHOM FHT

edt hetotte ef ttede ars desxd edt of .ti ade et -Motatg oft setrteo dotdw ,f ,relttss ef ,Molatq odt bas ,A ,xre98eg eft dviw sotdeem et {[sedw-rste A .f ,motmtq eft tiw antfeem -fot yetook 2 Baa .’ ,moiatq edt dtiw betavom 8 to moltes edt tebas ,tt taxtezs etaed ref es pool ee ,tnemegmerts etst yT .& ,anirge -~fool Leedw-rate edt ebfod rzelf[or yortoot sdt ettede edt ,¢ ,relxres ont sobtteoq ct be evfover [[s ,° Bea ,A ,atses antivir edt bas -nxrst et L[eedw-tesve ont ,tevewod YI .toedtegot efhbeatst era .I bas 2 ,enotatg owt edt , bo ot teeqees ditw eetsiow .4 ,retareas edd ine eit ot teeqeet dtiw oomed base ,A ,tesg odt -be et ore desctd oft todted¥ .totom anitwich .retom edt ot tooceet dttw ,bebrsetet to Seonsy -rete edt dotdw ef nottoerth eit soqn eimeqeb ferret et feedw

-roo end ef dotwfo edt wofed

THE MORKRUM SYSTEM OF PRINTING TELZGRAPHY

recting magnet, to whose armature is attach-

ed a small interference pin, P. The magnet

is so located that when it becomes energized,

it draws the interference pin into the path

of the star-wheel. Therefore, if the magnet

be energized while the star-wheel is revolv-

ing about the central shaft, the pin trips

the star-wheel through the angle of one tooth. The result of the movement

of the interference pin is the retardation

of the brush arm. As was just shown, the clutch

loeks the receiver shaft and the driving gears,

A and C, together, so that the shaft, elutch,

and gears revolve in unison. If however, while

they are revolving, the interfernee pin trips

the star-wheel, the carrier, B, the star-

wheel, and the shaft are stepped back slight-

ly. Thus, when the receiver brush gets too

far shead of the transmitter brush at the

100

0oL

YHIAHOH TAT DEITLIAI 2O Matera MUSAAOM HHT

-dosite et erutaors exodw ot ,temasre anttoer tornem eft .f ,otaq eonerotretat ([feme s be Sesitstene eemooced si mendw tadt betsect os at disq edt otat atq eomatetretmt eft eward tt vensgsm od tt ,eroteredT .[eenwerese edt to -vilovert et feedwertste edt eLiiw besinirene od eqis? mtg eit ,ttade {sttmee ext tyoda gat eivooy eno To efans odt dagpotdd feeswetate edt tremevom edt to timeer eT noltsirster sit et mtq sonerettetmt edt to dotefo edt ,mwode taut eeaw eA wore decrd edt To ,erses astvieh edt boe teste tavteses edt exool efotelo ,ttade ott test of ,tedtesot .0 bas A eftdw ,revewod tI .moetns at svfovet arses bas

eqist ata senmretretat edt ,anivfover era yodt

-rate eft ,2f ,refurss eft ,[sedw-tsate oft

-Sdatie wosd beqqets ere Stedea edt baa ,loodw oot etog darnd revteost edd codw .andl .¢uL

edit ts deord tottimenart odd to Baede ret

101

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

opposite station, a synchronizing pulse oe- curs, which eauses the corrector magnet to pick-up, and thereby apply a correction to the brush erp.

The retardation of the re- ceiver arm is very slight, but the driving motors run at such nearly constant speeds, that the arms turn through several revolu- tions before correction become necessary.

As was previously stated, the control of the corrector magnet is some- what different from that shown in Fig. 21. The correétor magnet does not have time to pick-up under the action of the synchroni- zing pulse. It is necessary, therefore, to prolong the influence of the pulse. Two re- lays are added to the scheme, one a quick- acting, and the other a slow-acting instru-

ment. The mechanical construction of the re-

fol

YAUSADTTIST DUITMILI FO MET CYS MUAAAOM FHT

-90 eeluq gxtsinordorye s ,nottete ettaoqgo ot gemssm totoettos ect geeveo dotdw ,etie ot moiftoerros s yiqqs yderedt bre qu-dolg

-grts desrd oct

-et eft to nottairatet eT gaivich est tod ,tdgtie yrev at mora revieo ,eboeqe tastenoe yireen dose ts ant erotom -plovet [stoves davordt arst ere ed? tedt eTrseepoen emosed moltoeriroe etoted anoltt

foteate ylesotverq saw eh -emor ef vemgam totosiroo eft to Lortnoo ont ofS .at® wk owode tadt mort diretetttd sade ot emtt evsd tor eo0b tenmsam rotoerros eT -trotdomye eft to mottos edt tebhbav qu-detg ot ,ototetent ,yresesooen at tI .eafsa oats

-eT owl .oefsgq edd to somenltat edt sano lotg -fotso s eno ,emedoer eft ot Behbs ors eval -urtest anttea-wols 2 terito oft baa ,gnttor

-eT eddy to noltourtenos [sotmexoem efT .trem

102

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

lays is the same as that of the relay pole ehangers, already described.

The new scheme, 28 is used in practical operation, is presented in Fig. 23. In this figure, the quick acting relay is marked "X", and the slow-acting is marked "Y", By reference to Fig. 23, we that when the correcting pulse is received, if the cam contact is closed, the current passes from the positive side of the lo¢al battery, through the printer relay and cam contacts, through the windings of X and Y in multiple, to the negative side of the battery. Relay X picks- up and eloses eontact a. The correcting mag- net is now connected across the local battery through the contacts a and b. Also, both re- lay windings are connected in multiple ecross the loeal battery. The slow-acting relay, Y,

now picks-up and opens contact b; the open-

Sof

YATASOARIRT OQUITUIAL TO MITEYS MUAAROM FHT

efog yelet eid to tedtd es omec oct ef eval eheditosed yheetlse ,eteanedo

feay et se ,emedoa won oT aii aot betmeretg eat ,wottereqo L[eoltioarq at yefer antioe aotep edt ,etuatt eft al .éS Sexzem ef anties-wole edt bas ,"%" hexzeam et redw tact ew ,eS .sti ot eeseteter yo 9 ee msec edt tt ,bertecer el sealing uattoetros elt mort eeneesq tnetiso eft ,boeofo ef tostnoo fasotdt ,yretisd [sso0f edt to sita evitinec edt dssords ,etostros mao Baus yelet sotaixrq ont edt ot ,elfgttinvum mt Y boa X to eantiatw odd -avolq X yale .yretted edt to site evitsser -ge0 geivserron efT .a sostnce aesolfo has gr yretied [ao00f adt aaores betsennos won st ten -et dtod ,osfA .d basa e etostnoo eft dasordt ‘eeotoe elqitiom mt hatoensoe ers egetiatw yal 3 oY ,yelet yoitos-wole efl ._yretiad fool edt

-xeqo eft :d sostsoo ensco bos qu-evotq won

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

ing of contact b de-energizes both relay wind- ings, so that the contacts a and b are open- ed. When a and b are open, the correcting mag- net is disconnected from the battery; hence, the magnet is de-energized. But in the mean- time, it has performed its synchronizing function, i.e., it has, through the agency

of the synchronizing eluteh, retarded the brush arm.

If, when the synchronizing pulse is received, the cam contact is open, (as it will be when the brush arms are in step) there is no current path through the cam contact to the relays X and Y. Hence, the relays are not energized and no correct- ing action occurs.

The purpose of the 200-ohm resistance shunted aeross the corrector mag-

net is to absorb the inductive kick, present

103

sol

YHUARVARIAT SULITMIRT TO MiTeYe NUAAZOM FHT

-batw yafeou dted sestoroeme-ef d toetmos to grt -seqo ets d bas se atostroe eit tadd os ,egat -gem gaitoettos edt ,meqo ers d ins s ned .be .eoned ;ytettad edt mort betoennooelh et tan -asem oft mt ted .bestgtens-eb et tengsm edt gpuisisonudomvye ett hemrotreq esd Ti ,emit yorens oft dasordt ,esd tt ,.8.f ,sottonut est fBebrater .detufo antsinorfonyea oft to. eoxs destd

antsicorsonzge eft sedw ,tT .teqo et tostnoo mso edt ,bevieost et safug nt ers same deord edt medw ed [ftw tt es) eit desordt dteq tmetiso om et eredt (qete ,ooned .Y Bre X eyelet oct ot toextmoes mao ~tosttos on bas hesigtreme tom eta syster ont eersooo mottos ant

mie-008 ent to esogrsg eAT -asu toteetros edt eaxctres betmide constateer

tnecet¢ ,forvt evitovbrt edt dtoads ot at ter

104

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

when the circuit of the magnet is opened, If this resistance were not provided, de- structive areing would occur at the eontact b or at the eam contact.

We will now complete the dis- cussion of the electrical cireuits of the distributor.

THE DISTRIBUTOR CIRCUITS. The complete eircuits of the distributor are shown in Fig. 24. It is obviously impractieal for us to attempt a study of the eireuits as pre- sented in this figure; hence, we will sepa- rate the constituent eireuits from the rest and study them one at a time.

THE MOTOR CIRCUIT. The motor eireuit is so simple that it need not be sep- rated from the other circuits of Fig. 24. 4s is indicated, the motor, together with the

governor contact and the 1000-ohm resistance

aol

YHLAAORIAT QMITUIAG TO MITAYe MUEQAOM FHT

efenego et tensem edt to ticerto edt sew ~eh ,hebiIvoxrq tom erew eonstetees etdy tI toastaos edd ta «wisso biyow goteve evisvourte etostace mae edd ts to d

~et6 edt etef[qmoo won iftw eV eit to ativzerte [aotrteefe eft to noltsero etovudtaters

eft .8TIVOHIO HOTUAIATaIC Har mwode ers totudiyteti edt to etisorte eteflamos rot fselvoeitqmt ylevoivdo et tI .AS wath at -eTg af eatinerio edt to ybute s tqmetts of os -ages [ftw ew ,eoned jetogtt etdt of betase test edt mort etiverte daentitance edd etet eemtt « ts so Modd yhote bas

xosvom edT ,TIUSHIO AOTOM RHT -qoe ed gon heem tit teddy ofamte oa eat siverto oSS .8f% To atlserts szedto edt mort betar edt ditw rediegot ,trotom oft ,betsetbat et aad

eoneteteer mic-O00L edt Sua toextn00 torreros

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

in multiple, are connected across the 110- volt battery.

TRANSMITTER DISK CIRCUITS, The circuits of the tape contacts and relay pole changers are Shown in Fig. 25. The con- nections are similar to those of the intro- ductory system shown in Fig. 6, except for the addition of the 900-ohm resistance, D, in series with the back points of the relay pole changers, and for the addition of the eut-out relay. The purpose of the resistance, D, is to prevent the short-circuit of the battery when one or more of the relay pole changer tongues are on their front contacts and the transmitter brush is on the corres- ponding button. The cut-out relay was dis- cussed before; it is controlled by the tape feed cut-out. As is indicated, when the cut-

out relay is de-energized, as is normally the

105

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YHLARDEIET QUITMIAI TO MaTeYe MUAAAOM THT

~Off edt seorors hetoernnoo ors ,efattiom at e“retisd tlov

eGTIVOAIO HEIGC AATTIMewsnt yalet bas eatogstnos eqet edt to etisorto eT -n09 efT .é& .2tt mt ovoda ors etegnadto slog -ortal edt to eeody of reflimia ers enoltioen sot taqeoxe .3 .2fl ot nwode moteye yrotordh 2 ,eousteteer mio-00@ eft to softtbhbhs odt yelet ect to atatog doad eft dtiw eotres nt eft to mottrbbs eft rot bas ,eteasedes slog ,comatetest edt to eeoqruq ofT .yefot duo-tuoe eds to tiverto-tyoda edt tmevetaq ot at ,C efoq veler edt to erom to eno nedw yretiad etostnos tnort rtedt mo ets eeranot teansdo -sertos eft mo ef devad tetiimenats edt das -8th eaw yelert tso-tso edT .nottod antbhaog eqat edt yd belfortmoo et Tf yeroted hereve -too edt cedw ,fetsothat et eA .tuo-tro boet

edt yifsoron ef es ,festareme~-ob at yeLlor tro

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

case,the armature rests against its back point,

so that the back points of all the relay pole changers are negative. When the cut-out re- lay is energized, by the closing of the cut- out cam contact, its armature is drawn over to the front point. When the armature is in this position, both the front and back con- tacts of the relay pole changers are posi- tive. Hence, by means of the cut-out mechan- ism, all-positive impulses are transmitted through the line whenever the cut-out is in operation,

Fig. 25 also comprises the circuits of the main line pole changer. The buttons of the transmitting disk are connect- ed to the tonguss of the relay pole changers; the brush arm is connected to one terminal of the main line pole changer; the other ter-

minal of the main line pole changer is con-

106

YHILADRIAT PULTUIAL TO MFTEYE MUARHOM THT

etatog dosd ett tentane sieet erpismts edt,eesso efoq yefor edt [fe to etntog toad ext tadt oe -et tvo-too est cedW .evitexzen ers atoacnesio -tuo ect to anteofo edt yd ,dbestureme ef yal t‘oevo mwath st etutamre ctl ,toestmaoos meo tro ot et exstenrs edt sef#¥ .tatoq snort eit oF -moo Hoed bas trort sdt dtod ,mottisog efst -teoq ete eteanesdo efoq yeler edt To atoat -~fetoem tgo-stuo sit to aensem yd ,someH .evit hettinenert sts seafsemt evititesoq-ifs ,met ot et ¢uo-tyo oft teveneds omti edt duvordt emolttateqo

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“00 ef tegmaio sfog omtl otsem edt to [anita

107

THE MORKRUM SYSTEM OF PRINTING TELEGRAPHY

nected to the local battery through the 900- ohm resistances, A, B, C, and D. A study of the connections of the main line pole changer and resistances will show that two 900-ohm resistances, A and B or C and D, are always in series with the main line pole changer while it is connected across the local bat- tery. Hence, the current through the coils

is limited to a value which the winding will safely carry.

The tongue of the main line pole changer is connected