US2408100A

US2408100A - Telegraph permutation code signal translator

Info

Publication number: US2408100A
Application number: US533106A
Authority: US
Inventors: Frank F Shipley
Original assignee: Bell Telephone Laboratories Inc
Current assignee: AT&T Corp
Priority date: 1944-04-28
Filing date: 1944-04-28
Publication date: 1946-09-24
Anticipated expiration: 1963-09-24

Description

P 1946. F. F. SHIPLEY TELEGRAPH PKRIU'I'ATIOH GODS SIGNAL TBAISLATOR Filed April 28, 1944 5 Sheets-Sheet 1 Ell 22236.3 9:. E E

INVENTOR F. F SH/PLEY BYJM... L. (W?

p 24,1946. F. F. SHIPLEY 2,408,100

TELEGRAPH PERHUTATION CODE SIGNAL TRAHSLATOR Filed April 28, 1944 5 Sheets-Sheet 2 can: mnrvmrm INVENTOR F. E SH/PL 5r ATTORNEY Sept. 24, 1946. F. F. SHIPLEY 2,408,100 TELEGliAPH PERMUI'ATION CODE SIGNAL IRANSLATOR Filed April 28. 1944 5 Sheets-Sheet 3 w. V, N pm m mm w m a A V WP l a v 8 09 Se t. 24, 1946. F. F. SHIPLEY TELEGRAPH PERMUTA'I'ION CODE SIGNAL TRAN SLATGR S sheets-sheet 4 Filed April- 28. 1944 I F. F. SH/PLEK BY 904.. a. m?

ATTORNEY Patented Sept. 24, 1946 TELEGRAPH PER-MUTATION CODE SIGNAL TRANSLATOR Frank F. Shipley, Tenafly, N. J., assignor to Bell Telephone Laboratories, Incorporated, New York, N. Y., a corporation oi New York Application April 28, 1944, Serial No. 533,106

8Claims.

This application relatesto the translation of permutation code telegraph signals in accordance with one code into permutation c'ode telegraph signals in accordance with a second and diflerent code. a

More specifically this application relates to the translation of five-element two-condition permutation code telegraph signals into threecondition signals some oi which have four elements andothers of which have three elements.

A system has heretoiore been proposed in which five-element twocondition permutation code telegraph signals are all translated into four-element three-condition permutation code signals. The system herein represents an improvement over said proposed system in that it eflects a saving in the time required for transmission due to the fact that the transmission of the three-element signals requires less time than the transmission of tour-element signals.

As is well known in the art due to the electrical characteristics of certain transmission channels, particularly long submarinecables, it is not possible',to transmit over them at a high rate of speed. as a result of thisa system oLtransmission ls'employed whe'rein each'signal element which'is over the cable may be oi any one of three conditions; namely. positive battery, negative battery or ground. with such an arrangement it. is possible to define a character with fewer-"signal elements than in a system wherein each signal element'may be of one of two conditions only. a

In the arrangement herein a system employing along telegraphchannel arranged for the slower three-condition signaling is used as a link to interconnect two stations arranged for the tester two-condition signaling. More specifically, a transmitting station arranged for the slower three-condition signaling is interconnected through a long submarine cable to a receiving station arrangedto receive the slower signals. The circuits are arranged in such manner that when five-element two-condition start-stop permutation code signals are to be transmitted over the cable, the cable is automatically seized at the transmitting end. The five-element two-condition signals are passed through a signal code translator which translates them into three'condition signals suitable for transmission over the cable. Two characteristic signal combinations are first transmitted over the cable. In response to this the receiving end of the cable is switched from its regular receiver and connected instead to a rctranslating mechanism.

In the retranslating mechanism the three-condition signal ele ments are retranslated into the original five-element two-condition signal elements, then the translated signals are impressed on a five-element two-condition receiving system. when the transmission of the translated two-condition signal elements over the cable is-terminated a characteristic stop signal combination is transmitted over th cable. In response to this the receiving end of the cable is automatically reconnected to its three-condition cable code receiver.

The invention is illustrated in its present embodiment on the accompanying drawings which discloses a system for attaining the maximum speed of transmission over a long cable employing the well-known cable co'de, wherein five-element two-condition start-stop permutation code telegraph signals are translated into three-condition cable code signals. In the .present embodiment twenty-tour oi the thirty-two five-element two-condition signals are translated into threeelement three-condition signals and the remaining eight five-element two-condition signals are translated into eight four-element three-condition signals. The invention may be understood from the following description when read with reference. to the associated drawings in which:

Fig. 1 shows the transmitting end 0! the meelement two-condition start-stop permutation code telegraph signal transmitting system and the transmitting end oi the three-condition cable code system:

Fig, 2 is'the transmitting signal code translator;

Fig. 3 shows the cable code receiver and the five-element two-condition start-stop receiving mechanism:

Fig. 4 shows the receiving code translator:

Fig. 5 shows an introductory diagram for explaining the relationship of themajor apparatus units 01' the system;

Fig. 6 is a cable code diagrani used in explaining the code translations;

Fig. 7 is a diagram used in explaining-the operation of the code translating pulse control relays. and

Fig. 3 is a diagram showing the manner in which Figs. 1, 2, 3 and 4 should be arranged physically each in relation to the other to form an operative system.

Refer now to Fig. 5. In Fig. 5 as mentioned above, the major apparatus units employed in Figs. 1 to 4 are shown in their relationship to each other. This will be explained as an introduction to a more detailed description to follow. The teletypewflter transmitting station 50! which generates five-element two-condition startstop teletypewriter code combinations is interconnected by means of two conductors 502 and 503 to a typing reperforator 504. The teletypewriter signal combinations transmitted from teletypewriter transmitting station 5M are received by the typing reperf orator 5M and punched in a tape 505. The punched tape 505 is passed through a transmitting distributor. The transmitting distributor impresses five-element twoconditions signals through the live conductors 5D! and the code converter 50!! which converts the five-element two-condition signals into threecondition signals some of which are three-element and others of which are four-element. From the code converter 508, the translated signals are impressed through the four conductors 589 on the relay switching circuit 5w. Cable code transmitter 5 is normally connected through switching circuit 585 to the cable transmitter relay circuit 5|2. When signals are transmitted from the teletypewriters station 5N, however, the system is arranged so that the cable code transmitter 5 is disconnected by the switching circuit 5N] and the teletypewriter signals are impressed through the cable transmitter relay circuit 5|2 on the cable conductor 513 which is enclosed in cable 5| 4. The cable extends to the distant receiving station where the cable conductor 5l3 is connected to a regenerative repeater 524 which is ordinarily connected through switching circuit BIG to the cable code receiver 5". Whenever the cable transmitter 5|2 is seized by the operation of the teletypewriting transmitting station 50 I, two characteristic signaling combinations are first transmitted over cable conductor 5l3. In response to this, switching circuit SIB- is controlled through pulse selector 5l5 so, as. to disconnect cable code receiver 5" from regenerative repeater 524 and the regenerative repeater 524 is connected through the-switching circuit 516 to the code receiving converter 5| 8. In. the code receiving converter the three and four-element three-condition signals are reconverted into five-element two-condition signals and impressed through conductors 520 and transmitting distributor SIS. The transmitting distributor 5l9 impresses the signals on conductors MI and 522 which extend to a distant teletypewrltlng receiving station 523,

Refer now to Fig. 6. Column Elli in Fig. 6 shows 26 letter and 6 functional symbols making a total 32 used in five-element two-condition teletypewriter code transmission. It shows also a Stop dmignation and a Start designation. The 32 fivmelement code combinations have marking elements in the signal element positions shown in column 602 and spacing elements in the other of the five positions of each combination. The marking elements operate correspondingly numbered relays in the code converter per Fig. 2. Column 603 shows the three and four-element threecondition code combinations into which the corresponding five-element two-condition combinations are translated. Reference to columns Bill and 6B3 indicates that 24 of the 32 fiveelcment letter and functional combinations shown in column 601 are translated into three-element cable code pulses and 8 of the 32 are translated into four-element cable code pulses. In column represents a. negative pulse, represents a positive pulse and 0 represents a ground pulse as the signal element transmitted over the cable in the signal element position indicated. The foregoing will become more apparent below.

Reference to the bottom line of Fig. 6 shows the word "Start" in column EDI and the bottom line in column E02 is designated "2 letters." This indicates that two fiveelement teletypewriter code combinations corresponding to the functional code combination for printing letter namely, and are translated into two four-element combinations, namely, and and are transmitted over the cable when the system is to be arranged for the transmission of translated teletypewriter code combinations. These combinations are employed in switching the receiving end of the cable mechanism only and are not impressed on the receiving translator. The second last line in Fig. 6 indicates that a distinctive combination. namely, is transmitted over the cable as a stop signal when the transmission of translated teletypewriter code signals over the cable is completed. In response to this particular combination the regenerative repeater 5| 4 is disconnected from the code receiving converter 5T8 and connected to the cable code receiver 5". There is no combination corresponding to this Stop combination shown in column 502. The reason for this is that the Stop combination is generated originally in the code converter in response to. the operation of a switch when teletypewriter transmission is ended and there is no corresponding five-element code combination required for the performance of this function.

Detailed operation of circuit The circuit per Figs. 1, 2, 3 and 4 is shown in the normal idle condition. When in this condition the armatures of relays 58- and 63 are actuated to engage their respective right-hand contacts under the influence 01' current flowing in a circuit which extends from battery through resistance 65, bottom winding of relays 63 and 58 and resistance 60 to ground. The circuit through the top windings of each of relays 5B and E3 is open. Relay 6B is released as key 4|, Fig. 2, is not operated and contacts 43c and Me are both open. Relay I04 in Fig. 313- released and the receiving regenerative repeater I is connected through contacts Ma and into to the cable code receiver I63. The cable codetransmltter I is well known in the art andwill not therefore be described in detail herein. .Regenerative repeater H4, selector I15 and the cable codc receiver I03 are also well known in then-rt and will not therefore be describedh'erein.

Relay 70, Fig. 1, is in the releasedccndltion and when in this conditionestabllshes circuit from battery through contact 18b through the tape feed mechanism 13 of the cable code transmitter to ground energizing the tape feed mechanism which is also well known in the art. Tape 15 is perforated in accordance with the continental cable code. The tape I4 is drawn into position so that the code combination apnearing in tape 14 is presented to the tape sensing mechanism. If the upper longitudinal section is perforated in a particular transverse position, contact 15 will be closed. Cam I is rotated by a mechanism not shown. Cam IE0 is arranged 50 that its associated contact 19 is closed durin three-quarters of a revolution of the cam and contact 19 is open during onequarter of a revolution. When contrct I9 is closed, a circuit may be traced from battery 80 through contact 73 and, if contact 75 is closed,

through contact 15, resistance 16,-conductorll2, contact 68a, top winding of relay 63 and resistance 64 to ground actuating the armature of relay 53 to the left closing contact 66. The tape M is so perforated that contacts 15 and TI are never closed simultaneously. The armature of relay 58 will be in engagement with its contact 62. A circuit may therefore be traced from negative battery through contact '66, contact 62' and cable conductor '91 which extends through the submarine cable to the distant regenerative repeater I14. In response to this signal the armature 94 will be actuated to close its contact 95in a well-known manner. A circuit may then be traced from positive battery I16 through 94, contact -95 and contact 4040 to the cable code receiver 103. Attention is called to the fact that, since contact Ill is open during a quarter of each revolution of cam Hit], the armature of

relays

58 and 153 will be under the influences of their biasing windings at'such times. Contacts '62 and '61 will therefore be closed and ground 'will'be connected to cable conductor 9| so as to discharge the cable. This is known in the art as curbing. Attention-ls also'oalled to the fact that, in addition to ground for curbing, ground -is also connected to cable 9| for orient the three signaling conditions'when contacts 61 and 62 are closed.

The regenerative repeater I" is under control of a tuning fork, not shown. The tuning fork is tuned to the speed of the sending'distributor and reproduces the pulse for each revolution. This mechanism is well known in the cable telegraph art.

'When the lower longitudinal-section of tape H is perforated in a particular transverse posit'ion contact ll will be closed. When-contact I9 is closed, a circuit may -be *traced from positive battery 80 through contact -"l8',-'-'contact 11, re sistance l8, conductor 8|, contact-liflcftop winding-of're'lay 58 and resistance 59 lac-ground actuating the armature of relay 58 to *the left toclose contact Kii. Under these circumstances, positive battery-is impressed throuhcontact 6! on regenerative repeater H4 actuating the'armature 93 to the left to'clcse' contact- 8B. A circuit may then be-traced from positive' battery through the armature 93, contact 96 and-contact lMe to 'cable'code receiver I03. If tape 14 is not perforated in either-one of its twopositions contacts J and 11 will both be open. The armatures of relays Stand 63 will be under the influences of their biasing windings and their armatures will be in the positions shown inF'ig. 1. Under this condition, a circuit may be traced from ground through contact 81 and contact 62 to conductor 9i. In response to this, the armature of regenerative repeater PM will be maintained in the position to which it was last actuated and the third of the three possible signaling conditions for an element will be impressed on the cable code receiver I03 in a. well-known manner.

It will now be assumed that the operator at the teletypewriter station Ill wishes to transmit. Switch I18 will be closed to energize motor l6. Switch II will be closed to energize the transmitter distributor. The keys of teletypewriter keyboard transmitter 3 will be operated. In response to the open and closed signaling conditions for the signal elements of the fiveelement two-condition permutation code the receiving magnet G of the typing teletypewriter will be successively energized and deenerglzed over a circuit which may be traced from the left-hand terminal of battery 2 through the contact of break key I transmitting contacts 3, winding of the teletypewriting magnet 4, conductor 5, winding of typing reperiorator magnet 6 and conductor J to the right-hand terminal of battery 2; It is pointed out that the teietypewriter station I17 may be interconnected to the typing reperforatcr 199 through long channels extending through a number of telegraph repeater and switching points.

When suflicient tape has been perforated, tape lever 9 will be lowered closing tape control contact If A circuit may then be traced from ground through contact l3, switch ll and the winding of magnet 12 to battery. The transmitter cam stop lever l3 will be actuated in a clockwise direction about its fixed pin H8 against the influence of spring I993. The right-hand end of lever I3 i disengaged from a shoulder on the periphery of cam I4. Motor 18 drives shaft 2a through clutch fl. Shaft 20 is coupled to shaft through worm l8 and worm gear 19. When cam I4 is released shaft I89 rotates drawing the tape 8 through transmitter distributor pins 2: to 25in a well-known manner. The operation of the transmitter distributor H9 described in detail in Patent 2,055,567 to E. F. Watson, September 29, 1936, the pertinent portions of which are hereby made part of this description. Successive transverse sections of tape 8 will be perforated with successive combinations of the liveelement two-condition code typed by the teletypewriter I11. There are five sensing pins M to 25 in the transmitting distributor I19. Where an element in tape '8 is perforated the corresponding contact 2la to 25a will be closed and where an element is not perforated the corresponding contact will be open. If a contact such as 2la is closed, a circuit may be traced from battery 26 through contact 2la, conductor 3!, contact 32c and the winding of relay 40 to ground operating relay 40. There is a corresponding circuit for each of the other contacts 22a to 250 which extends through conductors 21 to 30, contacts 32a to 3201.

conductors

35, 34, 33 and Bl and the'windings of relays 36 to 39, respectively to ground. A particular code combination perforated in tape 8 is presented to the sensing pins 1| to 2 5 of the transmitting distributor I19 simultaneously. The-circuits through the winding; of relays 38 to 40 are established simultaneously and relays 35 to 40 will be set in unison at a particular instant for each combination. Relays 36 to 40 will be operatedor unoperated depending upon whether its corresponding element in the five-element permutation code is a marking or a spacing element and noon whether it is represented by a perforated or an unperforated elemental area in a transverse section of tape 8. Each of relays 35 to 40 controls a plurality of contacts. The contacts of relays 35 to 46 will be set in conformity with the code. Relays 36 to 40 are also designated to 5 to facilitate reference to table 802 in Fig. 6.

To anticipate the description of the detailed operation of the circuit, it is pointed out that it is possible to establish a path from battery 88 through any one of four branches through the bank of pulse control relays shown in the righthand portion of Fig. 2 and through some articular one of conductors iii! to (84 which extends through the contacts of relays 35 to 40 shown in the left-hand portion of Fig. 2 and terminates either in conductor 03 or 64 which controls the operation of

relays

53 and 53. The pulse control relays shown at the right of Fig. 2 are arranged so that they first direct the battery pulse originating in battery Bil for the first revolution of a three or four revolution cycle of cam I60 to conductor I8I. Depending upon the setting of the contacts of relays 36v to 40, conductor I8I will be connected to either conductor 83 or to conductor 84 to control the proper relay of relays 58 and 63 so as to send either a positive or negative pulse through the submarine cable to the distant station. To obtain the third condition that is the ground signaling condition, when required, the path extending from conductor I 8| through the contacts of relays 36 to 40 will be open at some one of the switching points in the chain. When the circuit is open, relays 58 and 63 will be under control of their biasing circuits and ground will be transmitted for the particular signal element. The pulse control relays shown in the right-hand portion of Fig. 2 will switch the path extending from battery 80 through the contacts of the pulse control relays to conductor I82 for the second signal element of the code to be transmitted over the cable. The second element will, be positive battery, negative battery or ground, depending upon whether or not a closed path is provided from conductor I82 to conductor 83 or 84 or if the path from I82 to both conductors 83 and 84 is open. For the third revolution of cam I60 the pulse control relays at the right of Fig. 2 will connect battery B0 to conductor I83. The circuit is arranged so that ii the particular five-element two-condition combination has been translated into a three-element cable code combination the pulse control relays at the right of Fig. 2 will not progress after three elements have been transmitted but will restore the circuit so that the cycle may be repeated from the starting point. That is to say, after three pulses have been transmitted, battery 80, on the following revolution of cam I60, will be connected through the pulse control relays to conductor I8I to transmit the first element of the succeeding three or four-element code combination. However, if the five-element two-condition teletypewriter combination has been translated into a four-element cable code signal combination, this will be automatically recognized by a chain circuit through particular relays of the relay group 36 to 40 which are operated only when a five-element signal is to be translated into a four-element signal. The chain circuit will control the pulse control circuit so that, instead of restoring the pulse control circuit to normal at the end of transmisslon oi the third signal element, the pulse control circuit will progress so that battery 80 is connected through the pulse control circuit to conductor I84, which controls relays 58 and 63 in the same manner as does each of conductors IN to I83. In this case the fourth signal element is transmitted before the pulse control circuit restores the mechanism to the condition for the start of a new cycle of operations This will now be described in more detail.

Preliminary to the operation of teletypewriter II'l, locking key 4|, Fig, 2, will be operated, closing contact 42 and operating relay 63 over an obvious circuit. The operation of relay 43 establishes a circuit from battery through the Winding of relay 44 and contact 43b to ground, operating relay 44. A circuit may then be traced from battery through contact 44c and conductor 85 which extends through the winding of relay 68 to ground operating relay B8. The operation of relay 68 disconnects the cable code transmitter I15 from the cable transmitting relays 58 and 63 by opening contacts 68a and 68c. When relay 44 operates, it' locks over a circuit from battery through the winding of relay 44, contact 44b and contact b to ground. The reason for this will become apparent below.

While relay 68 is in the released condition a circuit may be traced from battery through contact 58g and the filament of lamp I85 to ground. Lamp I86 is lighted at such time to indicate that relays 58 and 83 are under control of the cable code tape transmitter I15. The closing of contact 68f establishes a circuit from battery through. contact 68], resistance 69 and the winding 01' re lay 10 to ground operating relay ill. The closing of contact llia when key 12 is closed establishes a circuit from battery through the contact of key 72, filament of lamp ll, contact 10a and the winding of relay ill to ground, locking relay 1D and lighting lamp II. The lighting of lamp ll indicates that the cable transmitting relays 5B and 63 are under control of the teletypewriter through the code converter mechanism. The operation of relay 10 by opening contact 'lllb deenergizes the tape feed mechanism 13 of the cable code tape transmitter I15. This stops the feeding of tape 14 through the cable code transmitter. Conductors 83, 8-1 and 8B are extended through contacts 68b, 58d and 68a, respectively. The closing of contacts 881: and 68d connectsthe output leads 83 and B4 of the code converter per Fig. 2 through the top windings of relays 63 and meets the motor lead or, as it is otherwise known, the battery feed lead, which extends from battery 80 through contacts 19, when closed, contacts 68c and through conductor 86 to the pulse control relays at the right oi Fig. 2.

It is necessary to insure that the first pulse which is transmitted through the cable after the transfer from the cable code tape transmitter to the code converter is not mutilated. This is performed by relays 49 and 50. After the operation of relay 68 it contact 19 is closed, or as soon thereafter as contact l9 is closed, a circuit is established from battery 80 through contact 79, contact 68c, conductor 86, contact 49c, contact c and the right-hand winding of relay 50 operating relay 50. Relay 5!) first locks over a circuit irom battery through contact 490, contactilla audits left-hand winding to ground. The operation of relay 50 by closing contact 50b extends conductor 86 through contact 50b and the right-hand windmg of relay 49 to ground operating relay 49. When relay 49 operates, the original locking path for relay 50 is opened at contact 590, but conductor 8B is extended through contact 4%, contact 50a and the lefthand winding of relay 50 maintaining relay 50 locked for an interval. When cam I has rotated into its curbing position contact I9 is opened and relay 50 will release. Relay 49 locks as soon as it is operated over a circuit which may be traced from ground through the left-hand winding of relay 49 and contact 490 to parallel branches. One branch extends through contact 430 to battery and the other branch extends through contact Me to battery.

When the curbing portion of the cam revolution is reached. conductor 85 is extended through contacts 49d and 58d to contacts of counting relays 5i and 52 and in parallel through contact 53d and contact 4871 to conductor IBI. The op oration of the counting relays will be described hereinafter.

It has been explained above that the first two combinations punched in tape 8 are two combinations corresponding to the teletypewriter letters function. This combination is the combination which is ordinarily used to control the receiving teletypewritlng so that after it has been typing figures it typesletters. In this, case, however, this combination is to be used tov switch the distant receiving end of the mechanism connected to the cable so that the cable is connected to the receiving codeconverter. The two. letters combinations are not transmitted into. the receiving code retranslator in Fig, 4..

As indicated in columns GUI and B03, in. re-- sponse to each oi the two five-element code.-com-- binations for letters which consist. of five marking signal elements relays 36 t 40 also designated l to5 will all be operated. When all the relays are operated, acircuit-may betraced from conductor l8l through contact 35h and contact 31k to conductor l3 fromwhich point the circuit extends through contact 6812, top winding of relay 63- and resistance 64. to ground operat-- ingthe armature oi relay 53 to close contact 63. A- negative. pulse will. be transmitted over the cableand' impressed through regenerative re,-

peater llL on the eight-pulse-selector I16; This is the first of the four negative pulses-into which each of the five-element combinations for lettors-is translated. In order tooperate the, eight.- pulse selector I16, it is necessarytotransmit eight negative pulses insuccession over the-cable. This will be eilected by the translation of two fiveelement letter combinations into two. tour-element code combinations each one of which latter elements is negative. As explained above,.after the first pulse is transmitted through conductor IN the second. third and fourth pulses will be transmitted through conductors [82, I81 and (M, respectively. Then. the cycle will berepeated. in response to the appearance of the second letters code combination in tape- 8. The pulsecontrol relays at the right-hand side of Fig. 2, as mentioned above, will effect the transfer of motor conductor 85 to each one conductors [82, 183.

andlflflin turn and thenwill repeat the cycle ductor 86, in addition to operating relay 63 to send a, negative pulse over the cable relay 5! will; be operated and locked to battery under controloi relay 46; The operating circuit forrelay 52 extends from conductor 86 through contact nd,, contact 50d, contact 52d, winding oi relay 52 and resistance 51 to groundpath extends from battery through contact 46d, contact 52c; winding of relay 52 and resistance. to ground. The operation oi relay 52 supplies batteryover a circuit through contact 46d and contact. 520 to the right-hand terminal of the. winding-f relay 5t, but the winding of relay it is shunted by battery supplied over conductor 85 through contact. Std which connects to the left-hand terminal of the winding of relay it, from which point the circuit extends through rwistance 56 to ground, so. that relay 5!- does not operate at this time. Rela 5| cannot operate as long as contact 19 remains closed.

When 19 opens, the shunt circuit is no longer effectivc and relay 5| operates, When relays SI and 52 are both operated a circuit may be traced from battery through contact 51b. contact 52b and the left-hand winding of relay 53 to ground. operating relay 53. When relay 53 operates, it

The locking 10 looks over a path. from battery and. through contact d, contact 531) and theright-hand. winding of relay 53 to ground. The operation of re.- lay 53- also connects motor lead 85thlQl1gh'Q0-ntact 53c, contact 54d and contact 48!: to. conductor I82. ated, a circuit may be traced from conductor I82. through contact 36! and contact 31! to conductor 83. When contact 19 again closes, the armature relay 53 will again be actuated to close contact 66 and. a, negative. pulse will be transmitted over the cable as the second. of the four-element code. pulses. When contact I9 closes relay 52 is released since the path through the winding of.

relay. 52 is shunted by battery through contact Me and resistance, 51 to ground. When relay 52 releases relay 5| will. lose its holding path since contact 52c through which battery was supplied for the holding of relay 5! isopened, However,

relay 5| will not release as it will be held op.- erated from battery supplied over conductor, 8.6 through contact 52d Relay 5| will be maintained operated by battery 80. through contact.

19 until contact 19 opens, when relay M. will release. When both relays- SI and 52 release, a circuit may be traced from battery through, contact 5la, contact 52a, contact 53d and the; left' hand winding of relay 5.4 operating. relay 5Q..

The operation of relay 55 transfers motor lead 88 to conductor. I83. The circuit maybe traced through contact 49d, contact d. contact no contact 54c, contact 558 and contact an to conductor I83. With relays 36 .to. 4li .operated; a circuit may be traced through contact. 400, contact 39c and contact 38c. to conductor llii. When batter lid is againconnected throughconductor 88 toconductor 83. the third negative pulse will winding of relay 55, contact 55c and contact 4611 to battery. The operation ohrelay 55. connects motor conductor 86 toconducto': I". The oil:- cuit may be traced through contact 4807, contact. 50d, contact 53?, contact 540, contact 55d and contact 48! to conductor I54. With relays 3! to 40 all operated, the circuit extends from 'conductor I84 through contact 38b and contact 38b to conductor 83. When contact 19 again closes, a negative pulse will be transmitted over the cable as the fourth pulse oi the fourelement. code. Relays 5| and-52 operate and release as previously described.

Relays, 36 to 40, as mentioned above, are numbered also i to 5. respectively. 'I'hisindicates that relays L to 5 are under control. of signal elements I to 5, respectively, of the five-element code. Attention is called tocolumns 602 and 503 of Fig. 6. Reference to these columns indicates that whenever a five-element signal is translated into a four-element signal. relays l and 2 are always among the relay which are operated. Further, when a fiverelement signal is translated into a. three-element signal. relays. l and 2 are never operated simultaneously. For the letters combination relays I, 2, 3, 4 and 5 are all operated. Since relays I and 2 are operated, a circuit may be traced from ground through contact 31b, contact 362). and the Winding of relay 41 to battery. operating relay 41. Therefore at the end of the fourth pulse a path is established Since relays 36 to 40 are all. oust-- which may be traced from battery through contact Sla. contact 52a, contact 53a, contact 55 contact 470. and the winding of relay 46 to ground, operating relay 45. This in turn opens the locking path for relays 53, 54, 55 and 46, releasing these relays preparatory to sending the succeeding character.

Returning to the interval during which the first character combination was sent, when relays 36 to 40 were operated they locked to the back contact of relay 45. After the first'pulse had been sent out and relays and 52 released they furnished a path which may be traced from battery through contact 5|a, contact 520, contact 530, contact 48a and the winding of relay 32, operating relay 32. This opened the operating paths of relays 35 to 40. The tape in the transmitting distributor was then advanced to the position of the succeeding combination by means of a mechanism attached to shaft I80. When relay 32 operated it too locked to the battery supplied through contact 45d. The operation of relay 46 at the end of the fourth pulse therefore 40 and 32.

The cycle just described will be repeated to send out the second code combination for letters to control the switching of the receiving end of the cable. Thereafter, the cod converter mech--. anism will be controlled in agenerally similar manner to translate as many combinations as appear in the tape. Relay 35 to 40 will be operated in accordance with the table indicated in column 602 to establish the proper paths in response to the combinations for the thirty-two letters and teletypewriter receiver adjusting functions indicated in column Bill. The proper combinations of positive or, negative battery or ground will be established byrelays 58 and 63 under control of the closed paths or open paths established through. the contacts of relays 36 to 40 for the various combinations. i 1

Attention is called to the fact that for twentyfour of the letter characters and functions indicated in column 6M, three-element signals only aretratismitted'over the cable? How this is perforrned will now be described.

Sincerelays 36 and 31 correspondingto signal elements I and 1.2 of the five-element. code. are never operated simultaneously when a three-ele ment signal is to be transmitted over the cable. some one of contacts 35? and 31b will always be open under such condition. Therefore, relay 4'! will never be operated when a three-element signal is to be transmitted. As a result of this at the end of the third pulse when relay 55 is operated, a path will be available immediately for the operation of relay 46. This path maybe traced from battery through contact 55!), contact 410, and the winding of relay 45 to ground. Relay 46 will therefore operate at the end of the third pulse and restore the circuit to its original stait ing condition immediately.

When it isv desired to stop sending, key 41 is restored to its original position. This releases relay 43. Nothing further will happen until the character in process of being sent has been transmitted. If the message has been completed the transmitter will be sending blanks, that is to say. all of the contacts 21 to 25 will be open and all of relays 38 to 40 will be released. In any event, relay 46 will be operated at the end of transmi sion of the combination in either one of the two manners heretofore described. A circuit may then be traced from battery through the winding of relay 48, contact 45!! and contact 430 to ground, operreleased relays 36 to ating stop relay 4B. When relay 48 operates it locks over a path from battery through the winding of relay 48, contact 48d and contact 44a to ground. As soon as relay 45 releases relay 45 operates over a circuit which may be traced from battery through the winding of relay 45, contact 450, and contact 48b to ground. The operation of relay 45 transfers the holding path for relay 44, through contact 450, contact 48b to ground. The operation of stop relay 48 establishes the proper combination for the stop signal indicated in the second last line from the bottom in column 603 of Fig. 6. This combination is Since this is a four-element signal relay 4! i operated through contact 48c to ground. The manner in which the operation of relay 48 sets up the stop combination will now be described.

For the first pulse battery will be impressed through contact 19, contact 58c, contact 49d, contact 50d, contact 53d, contact 48m, conductor 83a, conductor 83, contact 68?), top winding of relay 63 and resistance 84 to ground. This as has been shown results in the transmission of a negative pulse over the cable as the first element of the Stop signal combination. For the second element relay 53 will be operated as described above and the path from battery '89 will be transferred through contact 530, contact 54d and contact'48h' to conductor 83a which will result in the transmission of the second negative-pulse of the combination. For the third pulse of the combination relays 53 and 54 will both be operated. Under this condition the circuit from battery'illl will extend through contact 530, contact 54c, contact 55c, and contact 48! to conductor 846 which ex tends through conductor 84,- contact 58d, top winding of relay 58 and resistance 59 to ground. This results as has been previously shown in the transmission of a positive pulse as the third element of the four-element Stop signal combination. For the fourth element relays 53, 54 and 55 will all be operated. The circuit will therefore extend through contact 53c, contact 540, contact 55d, and contact 486 to conductor 83a which will effect the transmission of a neg'atlve pulse as the fourth elementof the Stop signal combination.

When-the four pulses of' the Stop signal combination have been transmitted relay '46 will againoperate. Since contact 46]) is opened relay '44 will release. This in turn releases the stop i relay 48, transfer relay 68 and relay 49. Relay 45 is a slow-to-release relay. Its slow release insures the release of relay 44 but with the release of relay 48, relay 45 releases. Relay 45 releases all other operated relays and the circuit is returned to normal.

Refer now to Figs. 3 and 4. The fork-controlled regeneratlve repeater Il4'which is maintained in synchronism with the sending'mecha-' nism will send the eight negative pulses into the pulse selector llfi in a. well-known manner. In response to eight consecutive negative pulses contact IE2 is closed also in a well-known man her. It is not possible for this to happen in response to any sequence of signal combinations other than two letter combinations in succession. The closure of contact I02 operates relay Hi4 over an obvious circuit. When relay I04 operates it locks over a circuit irombattery through contact 129d, contact I04] and the Winding of relay I04 to ground.

Whenever a positive pulse is received over the cable the armature 93 will be actuated to close contact and whenever a negative pulse is received the armature 94 will close contact 95.

Y and I219.

When a ground pulse is received, neither contact 65 nor 96 will be closed. Whenever a pulse is received, whatever its nature, whether-positive battery, negative battery, or ground,. the armature 91 will close contact 98 and connect ground through contact 96 and contact I04e to conductor I05. Contact 98 will open during the curbing interval between each pulse. The operation of" the regenerative repeater I14 which performs these functions is well known. When, in response to the pulses, ground is applied to conductcr I 65, which corresponds to motor conductor 85 in Figs. 1 and 2, relays I88 and I89, the wiring of which is substantially the same as that for relays 5i and 52, in Fig. 2, will be controlled in substantially the same manner as relays 5| and 52. Relays IIIl, III and H2 will be controlled in response to the pulses over conductor H15 in substantially the same manner as relays 53, 54 and 55 in Fig. 2. This combination of relays will function to count the pulses and advance the leads I05 and III! from one pair of translating relays to the next. Th only essential diflerence in operation is that the locking circuit for relays I68 to H2 extends through contacts I29b In the case of the first pulse relay H will be in the released condition as was the case for relay 53. If the pulse received over the cable is positive, the circuit will be extended through conductor I01, contact H0 and the winding of relay II4 to ground, operating-relay 4.. If the pulse is negative, the circuit; will be extended through conductor I06, contact -HIld.-and the winding of relay M5 to ground, operating relay H5. ductors I06 and II" willbe open and neither relay H4 nor relay IIIiwil be operated. The-eight relays II4 to I'll provide apair, oi relays for each of the four pulses. If aparticularpulse is posltive, a particular one of: the two relays corresponding to each pulse will beoperated and it it is negative, the other of the pair will be operated. If it is a ground pulse, neither one will be operated. After the first pulse is received, leads I06 and I01 will beextended through contacts H00 and Hile and contacts IIIdand Hit to the v windings of relays I.I 6- .and I-I1, either one. of wluch or neither of whlcl pwill be operated, in response to the second pulse depending upon the nature of the pulsev receivedoyerthe cable. Then conductors I06 and Iil'l. 'will be. extended through contacts IIlc and Hie and contacts II-2e and H2g to the windings of relays IIIland IIIlfor the third pulse. Upon the operation of relay H2. the circuit will be extended through contacts I 12d and H2] to relays I20 and I2] .for the fourth pulse.

Attention is called. to the tact that all fourpulse combinations transmitted over the cable and no three-pulse combinations have negative pulses for both of the first two pulses. This may be seen from reference to column 803. Each pair of relays of the relay group H4 to I2I is designated I+, I, 2+, 2-, etc. I+ indicates that relay H4 is operated when the first element of a combination received over the cable is a plus element. I- indicates that relay H5 is operated when the first pulse of a combination received over the cable is a negative element, etc. When the first and second elements of a combination are both negative elements, relay I and relay 2, designated H5 and III, respectively. will both be operated. For this condition a circuit may be traced from battery through contact Illa, contact II5a and the winding of relay H3 If the pulse is a ground pulse, both coni to ground, operating relay H3. Relay II 3 acts as a control to distinguish between three-element code combinations and four-element code combinations received over the cable. If relay H3 is not operated only three pulses are counted. Relay H3 controls relay I21. I-f relay H2 is cperated and relay H3 is released a circuit may be traced from ground through contact H211, contact II 3a, contact I29c and the winding of relay I21 to battery, operating relay I21. This condition will obtain for three-element signals. When relay H3 is operated and relay II 2 is also operated a circuit may be traced from ground through contact IGBa, contact Iil9a, contact II2b, contact H311, and the winding of relay I21 to battery, operating relay I 21. This condition will obtain for a four-element signal. 1

Relay I2I will therefore be operated at the end of the reception of a code signal combination whether the combination be a three-element or a four-element character. The operation of the particular relays of the group H4 to I2I, sets the contacts of these relays so that when relay I21 is operated the proper circuits will be esta.blished to control relays. I22 to I26 so as to establish the proper' five-element combinations corresponding to the three or four-element comblna-tions on relays. I22 to I26. Such of therelays I22. to I26 as are operated, look; through their I22brto I281) contacts and conductor I44 to ground through contact I43cr when contact- I43a is closed in a manner'to be described. When the brush arm I65 is in the stop position,- as shown, a circuit may be traced from battery through the winding of relay I43, segment I93,

brushes I53 and I62 and ring IE1 to ground I94-v maintaining relay I43 operated. The combinations established on relays M2 to I26 will be impressed through the corresponding contacts of the group I22a .to I26a and conductors. I to I49 on segments I to 5'01 the outer ring of distributor I3I. As brush arm IE6 is rotated, each one of segmenm I to 5 will be connected in turnthrough brushes I and I64 to solid' continuous conducting ring I69: From; ring.I 651 the circuit extends through. conductor 2, to the distant.

teletypewriter receivingstation I'H, andyreturns over conductor I13 to ground.- When the brush arm is in the stop position the circuit through the teletypewriter receiving mechanism is closed from battery through stop segment I90, brushes I65 and I64 to inner ring I69 from which point the circuit has been traced through the station to ground. When brush arm I66 sweeps over .start segment I9I the circuit through the teletypewriter station will be opened. This results in the transmission of the characteristic start Signal element of the start-stop signal train. Relay I43 will be released when rotatable arm IE6 of -distributor I31 moves oiT its stop segment. Segmerit I93 of inner ring I88: subtends the same angle as stop segment I90. Brush I63 will sweep oif segment I93 when brush I65 sweeps oil the stop segment. Relay I43 will b released at this instant and the combination which has been established on relays I22 to I26 will be locked thereon. Control relay I43 is released when brush I53 reengages segment I911.

The distributor I3! is under control of relay I'll. When relay I21 is operated a circuit may be traced from battery through contact I21], conductor I5I and the windin of start magnet I49, energizing magnet Hi]. When magnet MB is energized, rotatable arm I63 is rotated clockwise in a'well-knovm manner. When relay I2] is released, magnet Hill is deenergized and the rotation of arm IE6 is stopped with the arm in the stop position. The operation of relay I21 also releases the counting relays at the left of Fig. 4 by opening contact I219. The operation of relay I21 also establishes a circuit from battery through contact I21) and the winding of relay I28 to ground, operating relay I28. Such of the relays II to I2I. as are operated for a particular combination, lock, through contact I28h and contact I290 to battery. The opening of contact I2Ilh releases such of the relays as have been operated. The release of the translating relays II to IZI places the circuit in the condition for the reception of the succeeding character combination. The sequence of operation and release of relays beginning with the operation of relay I21 occurs within the curbing interval which. as explained above, is equal to approximately onefourth of the time of revolution of the sending cam I60.

When the stop signal combination is received, it operates stop relay I29. This circuit may be traced from positive battery through contact b, contact II'Ib, contact IIlla, contact I2Ia and the winding of relay I29 to ground. Relays H5, Ill, H8 and III are operated in response to the stop combination The operation of stop relay 29 opens the holding circuit for transfer relay IM which was traced through contact I29d which is now open. This returns the circuit to normal. Relay I21 does not operate in response to this combination so that the combination which is set up on the translating relays is not impressed through the contacts of relay 121 on th distributor I3I.

Refer to Fig. 6. The numbers in column 602 indicate marking signal elements in corresponding signal element positions of the five-element signal combinations for the symbol in the corresponding line in column BIII. Where a signal element position number does not appear in column 602 it indicates a spacing signal element in the corresponding missing signal element position number in the five-element two-condition code.

A marking signal element in a particular signal element position number, as explained above, operates a correspondingly numbered relay of the group at the left 01' Fig. 2. For a spacing signal element in a particular signal element position no relay in this relay group will be operated.

An examination of the combinations employed for any single character will illustrate the principle of translation. Take the letter I. for example, and refer to the sixth line from the top In columns MI, 602 and 693 in Fig. 6. The fiveelement two-condition combination for the letter f is translated into a three-element threecondition combination. The tape will be so punched at the sending end that the relays for signal elements I, 3 and 4, viz, 36, 38 and 39, will be operated. This will result in a closed circuit through conductor 83 for the first pulse, a closed circuit through conductor 84 for the second pulse and both conductors 83 and 84 will be open for the third pulse. This will transmit a negative pulse as the first pulse, a positive pulse on the second pulse, and a. ground pulse on the third. At the receiving end, relays for I and 2+, viz, H5 and H6, Will be operated. This will result in the operation of relays MI M3 and M4 or relays I25, I24 and I23 to reproduce the original signal. This in turn will produce marking signal elements in signal element positions I, 3 and 4 and spacing signal elements in signal element positions 2 and 5 to conform to the original fiveelement combination.

The translation of all of the other five-element two-condition combinations first into three or four-element three-condition combinations and then into the original combinations may be understood from the foregoing example and the detailed description of the translation of each is not considered necessary to an understanding of the invention.

What is claimed is:

1. In a telegraph system, a source of five-element two-current condition permutation code telegraph signals, a telegraph signal code translator, a telegraph channel, means connected to said source for impressing said signals on said translator, means in said translator for converting certain of said five-element signals into threeelement permutation code telegraph signals and others of said flveelement signals into four-element permutation code telegraph signals, and means connected to said translator for impressing said three-element signals and said four-element signals on said channel.

2. In a telegraph system, a source of thirty-two five-element two-current condition permutation code telegraph signal combinations connected to a permutation code signal translator, and means in said translator for translating more than half or said five-element combinations into three-element three-current condition telegraph signal combinations and the remainder of said five-element signal combinations into four-element three-current condition telegraph signal combinations.

3. In a telegraph system, a source of permutation code telegraph signal combinations, each of said combinations completely defining a symbol or function, each of said combinations consisting of 11 signal elements, each of said signal elements being of one of two possible current conditions, said source connected to a permutation code telegraph signal translator, means in said translator for translating certain of said combinations into corresponding combinations each having (n-l) signal elements, and means in said translator for translating the remainder of said combinations into corresponding combinations each having (11-2) signal elements. f

4. In a telegraph system, a source of at least thirty-two five-element two-condition. permutation code telegraph signal combinations con nected to an electromechanical permutation code signal translator, and means in said translator responsive to the reception of particular ones of said signal comblnatlons for translating said received combinations into particular ones of thirty-two three-current condition permutation code signal combinations certain of which are four-element combinations and others of which are three-element combinations.

5. In a telegraph system, a source of four-element and three-element three-condition permutation code telegraph signals connected to a permutation code telegraph signal translator, and means in said translator responsive to the reception of said signals for translating said received signals into five-element two-condition permutation code telegraph signals.

6. In a telegraph system, a source of five-ele' ment two-condition permutation code telegraph signal combinations connected to a first electromechanical translating device, means in said device for translating a number of said combina tions into a corresponding number of three-element three-condition permutation code telegraph signal combinations, means in said device for translating the remaining number of said fiveelement combinations into a corresponding number of four-element three-condition permutation code telegraph signal combinations, a second electromechanical translating device, a telegraph channel interconnecting said devices, means for impressing said translated signal combinations on said second translator through said channel, and means in said second translator for retranslating said translated signal combinations into their original form.

'7. In a telegraph system, a first telegraph station, a telegraph signal translator, a first telegraph channel connecting said station and said translator, a telegraph signal retranslator, a second telegraph channel connecting said translator and. said retranslator, a second telegraph station, a third telegraph channel connecting said retranslator and said second station, means in said first station for impressing a number n, equal to (b+c), of five-element two-condition permutation code telegraph signal combinations through said first channel on said translator, means in said translator responsive to the reception of b of said 11 signal combinations for translating said b combinations into b three-element three-condition permutation code telegraph signal combinations, means in said translator responsive to the reception of c of said n five-element combinations for translating said 0 combinations into c four-element three-condition permutation code telegraph signal combinations, means in said translator for impressing said four-element or said three-element combinations through said second channel on said retranslator, means in said retranslator responsive to the reception of said four-element or said three-element combinations for retranslating said four-element or said threeelement combinations into their original form, and means in said retranslator for impressing said retranslated combinations on said second station through said third channel.

8. In a telegraph signal transmitting and receiving system, the method of transmitting 1: permutation code telegraph signal combinations, each of said 1) combinations having 11 elements, each of said elements being of any one of m conditions, which comprises the translation of q of said n combinations into q combinations each having (n-a) elements, each of which (n-a) elements may be of any one of (ma-l-b) conditions, and the translation of the remaining (p-q) combinations into (p-q) combinations each having (n-c) elements, each of which (n-c) elements may be of any of (1114+b) conditions, in order to save transmission channel time.

FRANK F. SHIPLEY.