Патент USA US2403681код для вставки
July)9,1946." ' ’ L‘ M, Fons ' ‘‘ CIPHEkING S-YSTEM ‘Filed Sept. 18, 1944__ . _ - 157 2,403,681 45 2 Sheets-Sheet 1 FIG. -I 1 I64 Emmi-1112i“ :inailj 131:0»; 724M121 13mg ' mvem'on > L0 U IS M. POTTS ATTORNEY Juli’ 9,1946- ' - v ' . 1_. M. POTTS CIPHERING ~ SYSTEM Filed sept- 18, 1944 2m -, FIG- 2 I - 1‘ ' ‘2,403,681 I ' 2 Sheets-Sheet 2 256 202 " s21 INVENTOR .LOUIS M.-POTTS ATTORNEY Patented July 9, 1946 2,403,681 ‘UNITED STATES PATENT OFFICE 2,403,681 CIPHERING SYSTEM Louis M. Potts, Evanston, Ill., assignor to Tele type Corporation, Chicago, Ill., a corporation of Delaware ‘Original application October 19, 1942, Serial No. 462,523. Divided and this application Septem ber 18, 1944, Serial No. 554,636 3 Claims. ' (01. 178—71) a '1 This invention pertains to printing telegraph systems and particularly to a system for the trans . 2 are employed for transmitting purposes instead of a double wound relay. mission and reception of secret telegraph mes- ' . In order to .encipher messages ‘by the present ,system the elements of the original code combi nations are combined'with thev elements of code combinations provided by a key tape. In this sages. This application is a division of copending ap- . plication Serial No.'462,523, ?led October 19, 1942. Secret signaling systems are desirable for naval, military and civil purposes wherein it is re arrangement, opposite conditions, that is, with one element of the original code combination quired that messages be rendered uninterceptible marking and with the corresponding element of by persons unauthorized to receive them. The 10 the key code combination spacing, produce a surreptitious interception of messages may be ac complished, for example, in the case of wire com marking signal. Like condtions, however, that is, With-both elements marking or both elements spacing, produce spacing signals. This presumes, of course,'that each of theelements of the re munication by tapping signal wires and in radio communication by means of receiving/appara tuses tuned to the proper frequencies. 7 spective code combinations are related to each other. That is, the No. 1 element of the original code combination is combined with the No.’ 1 The primary object of the present invention is the provision of a reliable and practical telegraph circuit arrangement for rendering messages unin element of the key code combination, and ‘so forth. To take a speci?c illustration, let it be Another object of the present invention is the 20 assumed that it is desired to encipher the letter provision of a ciphering system for telegraph “R.” which in the Baudot code is composed con-v telligible to unauthorized persons. ' messages including an electrical circuit system which is automatically conditioned either to en cipher or decipher signals according to the direc tion of transmission. . ' > secutively of spacing, marking, spacing, marking, and spacing conditions. Let it be further as . sumed that‘the key tape with which the particua 25 lar enciphering operation is to be performed 00-. V A further object of the invention is to provide a portable self-contained’ enciphering and de cupies a position whereat itis conditioned for producing the letter “Y” combination which in ciphering unit that is easily and readily attach the‘Baudot code is composed consecutively of’ marking, spacing, marking, spacing, and marking ing apparatus having transmitting and receiving 30 conditions. Under the assumed conditions, the facilities. ~ enciphering operation would result in the produc; able and detachable to standard telegraph print- ' .In one form, the invention utilizes .a receiving distributor by means of which a set of five re tion of an all marking or “letters” combination since in this particular illustration opposite condi ceiving relays are conditioned upon the receipt tions of all the elements of “R‘” and “Y’f code of enciphered or deciphered'signals and a key' 35 combinations are provided. This will be readily tape transmitter for providing key signals. The apparent from the following chart wherein the let key signals are combined with the signals provided ter “M” indicates a marking condition and the by the receiving relay and produce resultant sig letter “S’f indicates a spacing condition. nals which are transmitted by means ‘of a trans mitter-distributor to a transmitting relay having 40 a pair of associated transmitting contacts, only one of which is e?ective for, transmission at a time dependent ‘on the direction of transmission. A second form of the invention features the use of a double wound relay for enciphering and Original signal Key signal “Y" ____________ __ Enciphered signal “letters"_ _ __ 3 4 5 s M M M S M s \ M M is, deciphering messages. One Winding of the relay It is understood that both the transmitting is under the control of key signals and the other and receiving end of a telegraph line will be winding is under the control of either enciphered. equipped with identical key tapes, which'during or original signals dependentupon the direction message transmission will occupy identical posi of transmission. In this instance, two distribu 50 tions. The key tapes are advanced during trans tors are provided, one for key signals and the ' ' mission to continuously modify the key signal, other for either the original or enciphered sig nals. A’ third form of the invention‘ closely resembles, but both tapes occupy the same corresponding position at all times. A station which receives en vciphered signals is thus enabled to decipher the I the second form except that two separaterelays 55, unintelligible signals transmitted over the tele 2,403,681 u) tion unit II at this time, and the distributor is above in connection with the enciphering opera tion will be continued and it will be assumed that a receiving station received the enciphered signal; brought to rest upon the impression of the stop or marking impulse upon magnet 44, which fol lows after every ?ve-unit code combination. In the rest position of the distributor 45, a circuit is namely, “letters.” The “Y” combination provided by the key tape at the receiving station can now be combined with the “letters” combination to de cipher the enciphered signals to thereby reproe 4 fore-break contact 48 to ground. The operation of start magnet 44 releases distributor 45 for the reception of a signal code combination from sta graph line by combining enciphered signals with key signals provided by its key tape. 'I‘o illus trate a deciphering operation, the example given made for relay 5| which may be traced as fol ii) duce the original signal “R” as clearly shown in the following chart: lows: From battery 52, through the winding of relay 5i, over conductor 53, through segment 54 of the distributor, over the brushes 55, and through conducting ring 56 to ground. As brush 55 moves off segment 54, the circuit for re lay 55 is broken, whereupon armature 51 is re leased to open contact 49 to break the energiz ing circuit of start magnet 44, and moreover, direction relay 39 becomes locked up over the following circuit: From. battery 35, through con tact tongue 35 of direction relay 3?, over con The invention may be more readily understood from the following detailed description and the drawings wherein, Fig. 1 is a circuit diagram of the main embodi ment of the invention; Fig. 2 is a circuit diagram of a second form of the invention; Fig. 3 is a circuit diagram of a third form of the invention; and Figs. 4 and 5 are schematic views showing meth ods of interconnecting communicating stations. Referring now to Fig. 1, the ?rst form of the invention will be described in detail. In order to facilitate the description of the ?rst embodiment of the invention, it will be assumed that a local station comprising unit i l desires to communicate with an outlying station over a loop circuit indi- cated at 12. In order to make a local record and check the operation of enciphered signals, a check printer I3 is provided which, by means of the plug and jack arrangement shown at 14, may be read ily plugged into the loop circuit. Similar plug and jack connections for the station unit I l and the loop l2 are shown respectively at l5 and 15. The apparatus is provided with a manually-oper ductor 33, through the winding of direction relay 39 (now energized), through its associated con tact tongue 6|, over conductors 52 and 63, [through contact tongue 51 of relay 5| (now de energized) and through contact 58 of the make before-break contact 48 to ground. With direction relay 39 thus energized, its con tact tongue 84 is held attracted so that transmit ting contact 25 or‘ transmitting relay is shunted out of circuit ever conductors 21 and 66 inasmuch * as at tlfis time it is desired to transmit from sta tion l I to the remote station over the transmit ting contact iil. This prevents the operation of contact 25 from interfering with the operation of the circuit under the ?rst assumed condition ' with station H transmitting, At this time, the direction relay 39 also» holds its associated tongue E8 in its attracted position so that contact tongue 13 associated with relay ‘H is shunted out of cir an cult and rendered ine?ective, in view of the fact that it is necessary at this time that outgoing sig nals which are transmitted through the relay "H do not interfere with the operation of the circuit. This shunting circuit is as follows: From contact tongue 58, over conductor ‘I2, through contact able switch shown generally at IT, by means of i which the local station unit ll may be condi ' tongue 13 (if it should be attracted by its asso tioned to transmit and receive either regular ciated receiving relay 1 I) over conductor 14, over telegraph messages or enciphered messages. conductor 15, and over conductor '16 back to the When it is desired to transmit or receive en contact tongue 68. ciphered messages, switch I1 is operated to its The operation of direction relay 39 further upper or coding position, and conversely, when results in the attraction of its contact tongue it is desired to transmit or receive regular tele 1'! to deprive direction relay 3'! of battery so graph messages, switch i1 is positioned to its that the local station unit Il may assume com lower position. plete control of the circuit, and therefore sig The circuit for .the local station unit H may be traced as follows: From battery l8 through the winding of receiving relay 22, over conduc nals from a remote station at this time will be transmit, the just-described circuit is interrupted station unit H by the local relay 22, contact ineffectual to seize control of the circuit. After every revolution of the distributor 45, brushes tors 23 and 24, through contact tongue 25 of 55 return to their rest position whereat the transmitting relay 2%, over conductors 21 and 28, previously described circuit is made to the re through tongue 29 of switch l1, over conductor lay 5| which by its operation attracts its tongue 31, through the station H, back over the con (5O 51 to break the locking circuit to relay as to ductor through tongue 33 of switch l1, ‘and return the circuit to normal in preparation for subsequent operations. over conductor 34 to ground: When local station unit If commences to As the original signals are received from and relay 22 is de-energized due to the transmis 65 tongue 3! is operable to make and break the sion of the start or no current signal. When following circuit, according to whether mark this occurs, the following circuit is established: ing or spacing impulses are being transmitted: From battery 35, over tongue 36 of direction re From battery 82 through the windings of the lay 31, over conductor 33, through the winding receiving relays 83' (receiving marking signals), of direction relay‘ 39, over conductor 4|, through 70 over conductors 84 to ,88, dependent upon the contact tongue 42 of receiving relay 22 (now de code combination being transmitted, through energized), over conductor 43, over conductor 46, associated segments 89, over brushes 9|, over through the winding of start magnet 44 asso the solid conducting ring 92, over conductors ciated with receiving distributor 45, over cone 75 93 and T2, through contact tongue '68 (now at ductor lil, and through contact 49 of make-be / wags; tracted) of direction relay 39, over conductors ‘16 and 95 and through the contact tongue 8| of local receiving relay’ 22 (when marking ‘sig nalsare being received and receiving, relay 22 is accordingly energized) to ground. . When a particular receiving relay 83 becomes ductor I 23, through the solid conducting ring I24 of ‘the transmitter distributor II 3, through brushes I56 and segments “1, over a particular ‘ conductor. I55 conditioned for operation through a tape feeler contact tongue I22', over either the conductor I26 or I21, and through a contact energized over the just-described circuit, it is tongue I 2I to ground. , locked up as follows: From battery 82, through In order to provide for the previously men' the winding of a particularrrelay '83, over its tioned overlap condition, the lower two receiv contact tongue 96, over conductor 91, and 10 ing relays 83 will cooperate by means of their through contact 98 of locking relay 99 to tongues I2I with the lower two tape feeler con ground. Prior to the reception of each signal tact tongues I22 in a slightly different manner. code ‘combination, locking relay 99 is momen When either of the lower two tape feeler con tarily energized to break previous locking cir tact tongues I 22 move to their lower, or marking cuits, which may have been completed over the 15 position, upon the sensing of a perforation in following circuit: From battery IOI, through the key type,v a circuit is completed upon the the winding of locking relay 99, over conductor operation'of overlap control relay I4I. Only the I02, through segment I03 of the distributor 45, over the brushes 55, and through the solid con operation of the lowermost overlap relay I3I will be‘ described. The circuit is as follows: 20 From battery I32, through the winding of relaxr In’ order to effect the enciphering of out I3I, over conductor I42, through feeler contact going messages and the deciphering of incom- , I22, over conductor I44, through contact tongue ing messages, there, is provided in the cipher I45 of overlap control relay I4I (when operated) ducting ring 56 to ground. ' ing system of the present invention, a key tape transmitter indicated generally at III which utilizes a key tape H2‘. It will be understood, of course, that each station will be provided with identical key tapes which occupy identi cal positions during communicating operations. Theonly prerequisite is that at any particular . instant or communicating operation, the key tapes at the interconnected stations be identi cal, because the key tapes may be different at diiferent times or operating periods. En ciphered or deciphered signals dependent upon to ground. When contact tongue ' I45 is at tracted by overlap control relay I4I,' as will be later explained, make-before-break contact I46 will be operated to break a previous locking cir ‘cuit for either of the overlap relays I3I if they have been previously energized in a preceding signal code combination. This locking circuit extends from battery I32, through the Winding of relay I3I, over contact tongue I5I, conductor I52, and through make-before-break contact ‘M5 to ground. It is thus apparent that if in the immediately preceding signal combination lower the direction of transmission, are delivered to tape feelers I2'2 were in their spacing positions the transmitting relay 26 through the instru their associated overlap relays I3I would not have mentality of a transmitting distributor II3. been operated, and. consequently, although Shortly after the operation of» the receiving ‘tongue I45 will operate; it will not unlock any distributor 45,'segment II4 thereof is traversed 40 circuit inasmuch as there was no circuit pre by the brush 55 and a circuit is completed to viously prepared for the relays I3I. The oper the start magnet II5 of the transmitting dis ' ation of tongue I45 also performs the function tributor I I3 from‘ ground, through solid con of providing ground over conductor I44, through ducting'ring 56, over brushes 55, through seg the windings of relay I3I if they are prepared by ment I I4, through the winding of start mag a marking condition‘ of feelers I22 for a marking operation in the next position of key tape II2. place transmitting distributor H3 in operation. Overlap control relay MI is momentarily ener It' is, therefore, observable that the transmit gized at each cycle of operation of distributor 45 ting distributor II 3 lags behind ‘receiving dis prior to the transmission of the signal code com tributor 45, the purpose of which is to provide 50 bination over the following circuit: From battery an overlap arrangement to secure the proper I41, through the winding of relay I4I, over con margin of operating time for the ciphering op ductor I53, throughvthe contact segment I 54 of eration, to insure that the receiving relays 83 distributor 45, over conductor ring 56, to ground. net II5, and through battery I I0 to ground, to and the key tape II2 are properly conditioned accordance with the combined positions of for operation at the required time interval. 55 In tongues I33 of overlap relays I3I and the tongues As the receiving relays 83 respond to signals, I2I of the lower two receiving relays 83, ground associated tongues or armatures I2I are either attracted or not, depending upon whether a marking or a, spacing signal is impressed on stor I may be furnished when marking conditions occur over either conductor I34 or I35, through the contact tongue I33, over conductor I55, through ing relays 83. The circuit for the upper three brush I 56, over the solid conducting ring I24 and receiving relays 83 is so designed with respect over conductor I23, through the winding of trans to the upper three tape feelers I22 of key tape mitting relay 26 to battery I I6. I I 2 that a marking signal will be produced when During each revolution of distributor 45, step‘ the tongues I2I of the relays 83 are conditioned to a position opposite to that of the correspond 65 ping, magnet I29 is operated to step the key tape to a new position as stepping control relay I30 is ing tape feelers I22. On the other hand, when momentarily energized over the following circuit: a particular contact tongue I2‘I moves to a posi From battery, through the winding of relay I36, tion similar to the position assumed by its asso over conductor I40, through brushes 55 and over ciated tape feeler I22, the circuit is conditioned .to produce a spacing signal; therefore, when 70 the solid conducting ring 56 to ground. Relay I 39 attracts and then releases its tongue I56 to con contact tongue I2I and tape feelers I22 are both trol an obvious stepping circuit to stepping mag marking or both spacing, a'spacing signal will be sent. The circuits for marking signals may net I26. Due to the overlap feature which has be traced as follows: From battery I I6, through been described,the stepping magnet is operated ‘the winding 'of transmitting relay 26, over con 75 while the fourth and ?fth signals are being trans 2,403,681 mitted since overlap relays l3 rare locked up and retain the fourth and ?fth elements of the signal code of the previous code combination when these elements are conditioned for marking impulses by the key tape I 12. When spacing signals are pro vided in the fourth and ?fth elements of ‘a key 8 tongue I63 of receiving relay 1| (now de-ener gized) , over conductor 46, through the winding of start magnet 44 of the receiving distributor 45, over conductor 41, through the make-before break contact 48 associated with relay 5!, to ground. Therefore, at this time, the distributor 45 is released for a cycle of operation through the code combination by the key tape, tongues I33 operation of start magnet M ‘and the direction of the overlap relays [3! will remain unattracted relay H is energized and becomes locked up over in spacing position. following circuit after brush 55 [passes off of As relay 2%) is affected by the enciphered sig 10 the segment 5:! to cause the de-energi'zation of relay nals, its contact tongue 6‘! is opened and closed 5!: From battery 35, through tongue 11 of direc according to the signals that are being trans tion relay 39, over conductor Iii-1, through the mitted to the remote station. The signals trans winding of direction relay 31, through contact mitted, are, of course, start-stop code signals. The key signals (that is, the signals controlled ‘ tongue [l2 (now attracted), over conductors 62 and '63, through tongue 51 of locking relay 5| and by the key tape) are provided only for the code through make-before-break contact 48 to ground. impulses and not for the start and stop impulses, The attraction of tongue 35 by the direction re the latter impulses being invariable and are sup lay 31 vbreaks the possible operating circuit for plied independently of the key tape by the ‘dis direction relay 39 so that again it is apparent that tributor segments H8 and N9 of the distributor the station which ?rst seizes control of the sys H3. Since the normal stop condition of the line tem prevents the other station from ‘operating is marking, the stop impulse impressed on the line during a signal code combination. is controlled by the energized relay 26, whose cir When direction relay 31 operates, contact cuit under this condition extends from battery H3 associated therewith is attracted so H8, through the winding of relay 26, over con- 25 tongue that contact tongue 61 of transmitting relay 26 ductor I23, over solid ring I24, over brushes I56, is short-circuited in order to suppress interfer and through stop segment MB to ground. Then ence by this contact with the circuit ‘at this time. upon initiation of transmission, when start mag This circuit is as follows: From ground, through net I I5 is energized and brushes I56 are caused to contact tongue I13 of relay 3?, over conductors 30 traverse the segments; the traversal oi brushes H4 and £59, through contact tongue 61 to ground. E56 over the start segment H9 will produce a no It is thus obvious that when the contact tongue current condition on the line, since no battery is 61 operates inasmuch as it is directly grounded, connected to the start segment H9. Hence, the it will not cause the repetition of signals at this circuit previously traced for relay 2%; will be time. broken, and relay 2% will become de-energized to Operation of direction relay 3? further causes release its armatures 6i and 25 to transmit start the attraction of its associated contact tongue impulses, either‘ to the line 12 or to the local unit H5, and ground for the storing relays is fur H, depending upon the short circuit condition nished over the following circuit: From battery of said contacts 61 and 25, as previously described. 82 to a particular receiving relay 83, over one of This causes the opening and closing of 100p cir the conductors Bil to 38, through its associated cuit l2 to operate a printer at the remote station. contact segment 89, over brushes 9!, through the This circuit is traceable as follows: From ground, solid conducting ring 92, over conductor 93, through transmitting tongue 61, over conductor throughcontact tongue 13 of relay ‘H, overcon I59, through the winding of relay ‘H, over con du'ctor "ii-i, through contact tongue H5 (now at 45 ductor I51, through the lower switch tongue 158 tracted) of direction relay 31, to ‘ground. of switch ll, over conductor I58, through the Distributors 45 and H3 will act in the same plug and jack connection it, through the out manner aswhen signals were being sent out or going part of the loop to the remote station, back transmitted, to now decipher the incoming sig through the plug connection [6, through the nals to cause the deciphered signals to ‘be re plug connection [4 of the check printer 13, over 50 peated by the transmitting relay 25. It will be conductor ltl, through switch tongue Hill of remembered that contact tongue 61' of transmit switch i1, and over conductor “32 to- battery I49. ting relay 26 is now short-circuit-ed and rendered The encip-hered signals which will be printed by ineffective for transmission. However, at this the check printer l3 are also transmitted over the time, transmitting contact tongue 25 is condi outgoing loop circuit ['2 to the remote station 65 tioned for operation and may make and break either directly or through a central telegraph the circuit to the local station unit H to enable of?ce or exchange. The system having now been the local printer to print the incoming signals described with respect to transmission of out in their original or deciphere'd condition. This going enciphered signals, a description will now circuit is as follows: From battery 18, through be given wherein enciphered signals are received 60 the winding of local receiving relay over con over the loop circuit l2 from a remote station and are deciphered by the ciphering system. Since the normal condition of the remote sta ductor 23, over conductor 24, through contact tongue 25 (when attracted) of transmitting re lay 25, over conductor 27, over conductor 23, tion in its idle or rest position is marking (cur through upper contact 29 of switch ll, over con rent on the line conductors), the relay ‘II will be 65 ductor til, through the local station unit ll, over energized over the previously described circuit including conductors I57 and £62. Thus, when, conductor 32, through tongue 33 of switch I], and over conductor M, to ground. The circuit code signals are received from the remote sta shown in Fig. 1 therefore provides a ciphering tion, the start impulse will cause relay ‘H to be system in which messages may be either en come de-energized. When this occurs, contact 70 ciphered or deciphered dependent upon the di tongue I93 of receiving relay "H is released and the following circuit is completed: From battery 35, through contact tongue 11 of relay 39, over conductor ltd, through the winding of direction relay 31, over conductor I55, through contact 1 rection of ' transmission. Another form of the invention about to be de scribed is shown Fig. 2. The circuit shown in Fig, 2 resembles the circuit shown in F151. 2,403,681 9 . . Particularly, in. this form of the invention there is provided,no..overlap*feature,‘and a double wound transmitting relay 205 is employed instead of a singlewound transmitting relay 26. The circuit for Fig. 2, therefore, will only be described with respect to the portions wherein it varies from the disclosure of Fig. ,1. , _In the modi?cation, a distributor 20! and a . 10 ‘ and contact tongue 235 is rendered e?ective for transmission. - When opposite conditions exist in the windings of the double wound transmitting relay 205, that is, with one winding conditioned for marking sig nals and the other winding conditioned for spac ing signals, the relay will become unbalanced and its transmitting tongues 234 and 235 at distributor ‘202 are "driven in synchronism upon tracted. In other words, the two windings of the same rotary shaft, and at a speed suitable for 10 double wound relay 205 are wound reversely, and the speed of transmission used. When start mag thus have the effect of neutralizing each other net 263 receives the start or no-current impulse when current vis present in both- windings‘, so at the commencement of transmission, the dis that a condition of current in both windings is tributors are released for operation, and both the same as current in neither winding, and in brush arms now move together. Storing relays 15 both cases the armatures 234 and 235 willbe 204 will be conditioned in the manner described released. On the other hand, .current in one in connection with relays 33 of Fig. 1 to energize winding and no current in the other Winding the left-hand winding of double wound trans will have the effect of attracting both armatures mitting relay 205 when marking conditions oc 234 and 235, but only one armature will be ef cur, over the following circuit: From battery 200, 20 fective for transmitting signals, since the circuit through the left-hand winding of relay‘ 255, over including the other armature will have been conductor 206, through the conducting ring 201, short-circuited. The circuit in Fig. 2 is in other‘ over brush 209, through a particular segment respects similar to the circuit shown in Fig. 1, 208, over a particular conductor 2!! now condi and it is therefore deemed unnecessary to de tioned, through a particular contact tongue 2! 2 scribe again the circuit in detail. to ground. As a particular storing relay 204 be Another form of the invention is shown in Fig. comes operative, it is locked up over the follow 3 which is similar to that shown, in Fig. 2‘ except ing circuit: From battery I99, over conductor that instead of the employment of a singledouble 2!3, through the winding of a particular receiv wound transmitting relay, as relay 205, there are ing relay 204, through contact tongue 2!,5now provided two separate transmitting relays 25! attracted, over conductor 2i6, ‘and through con and 252 operable by the identical circuit shown tact tongue 2!‘! (when released) of relay 2|8 to in Fig. 2. In the drawings, conductor 356 is the ground. In the rest position of the distributor same as conductor !50 of Fig. ,1, and conductors 20!, preceding each signal code combination, re . 321, 366,- and 328 are respectively the equivalent lay 2!8 is energized to attract its contact 2 I‘! and of conductors 2'1, 65, and 28 of Fig. 1.. thus break any locking circuit which may have 'Relay 25! is operable either byvenciphered or been previously established in the immediately original signals to control its transmitting con preceding signal code combination. This circuit tacts 253 and 254. When the local station unit is as follows: From battery 2|0, through the 255 is transmitting'enciphered signals over loop winding of relay 2l8, over conductor 2l0, through circuit 256 to a remote station, contact 253 is segment 220 of distributor 20! , over brush 209, e?ective and contact 254 is shunted out of the through segment 22!,'to ground. circuit due to the operation of the direction send In synchronism with the operation of the stor ing relay 25‘! which attracts, its contact tongue ing relays 20s to control the left-hand winding 364. On the other hand, when incoming. signals of the double wound transmitting relay 225, key 45 are 'being received from the distant station ‘con signals are furnished for control of the right (tact 253 is short-circuited due to the closure of hand winding of said double wound transmitting contact 258 upon the operation of the direction relay through the instrumentality of a key tape sending relay 259. At this time the direction relay 222. Prior to the transmission of signal code 25'! is unoperated and armature364 is released to combinations under the control of the key tape 50 render transmitting contact 235 eifective. transmitter during each cycle of operation, tape It has already been explained that the cipher stepping magnet 223 is operated, to step the tape ing system herein employed is predicated‘upon to a new position, over the following circuit: the combination of key signals provided by a key From battery I98, through the stepping magnet, tape with either original or enciphered signals. 223, through segment 224 of distributor’ 20!, over 65 Under opposite operating conditions. that is, with the brushes !91 and through the segment I96 to one element of the code, provided by the key sig ground. , r nals, marking, and a corresponding element of the The circuit for the right-hand winding of‘v re; code, provided by an enciphered or original signal, lay 205 is as follows: From battery,‘ through the spacing, produces a marking condition of the right-hand winding of relay 205, over conductor 60 signaling line. 221, through solid conducting ring 228 of dis- 7 Like conditions, however; that is, with both elements of the code marking or » _both elements of the code spacing, produce tributor 262, over the particular segment 229 spacing conditions of the signaling line. Refer conditioned, over a conductor 23!, through a'tape ring again to the circuit shown in Fig. 3, it can feeler contact lever 232, through the lower-or marking contact I95, and over the conductor 233 65 be seen that according to the provision of key signals for the relay 252 contact tongue 26! will to ground. When signals are being transmitted be operated, and it is apparent that ground'may to av remote station, transmitting contact tongue be carried over either conductor 262 or 263 to the 234 is rendered effectiveas hereinbefore described contact tongue 253 of relay 25! when opposite in connection with contact tongue 6'! of Fig. 1, and transmitting contact tongue 235 is rendered 70 ‘conditions exist. As contact 253 moves back and ‘forth, it makes and breaks the circuit to the re ineffective ‘by the short circuit including conduc mote station over the loop circuit 256 thereby to tors 327'and 366 and contact 364. On the other transmit enciphered signals to the remote station. hand, when signals are being received from a re However, when incoming signals are received mote station, contact tongue 234 is short-circuited 75 from the remote station over line 256, receiving 2,4;03,681 11 relay 25] receives signals in their enciphered con dition, and its associated contact 254 is adapted to cooperate with contact 2555 to make and break the circuit to the local printer 255. At this time contact tongue 364 of direction relay Z5‘! is open and consequently in this direction of transmis sion, conductors 32‘! and 3% do not provide a shunt circuit. Conductor 2H now receives bat tery through the winding of relay 212, over the 10 conductor 21!, through the conductor provid ing battery for transmitting contact 255% which may be extended over either conductor 212 or 213. Therefore, contact tongues 254 and 251% will oper ate together to make and break the local circuit to the. printer 255 according to signaling condi ' tions. In Figs. 4 and 5 are illustrated schematically a method, of connectingv intercommunicating sta tions, whereby a convenient way of reversing the loop circuit at said. stations isv provided. As pre- ~_ viously described, the loop circuit of the system shown in Fig. 1 extends from ground, through contact 51, over conductor I58, through the winding of relay ‘H, over conductor I51, through switch ll, over line loop l2 to the distant station and returning again through the switch l1, and then over conductor I52 and through battery I48 12 What is claimed is: 1. In a repeater system, a double wound relay, two line sections, one of the windings of said re lay associated with one line section and the other winding associated with the other line section, signal repeating means controlled by said relay, switching means to condition the circuit for re peating in one direction or the other, and means operative upon initiation of a signal in one line section to disconnect the winding associated, with the other line section. 2. In a telegraph system, a double wound re lay, two line sections, one of said windings asso ciated with one line section and the other wind ing associated with the other line section, a re peater controlled by said relay and adapted to repeat signals from one line section to another line section, switching means to condition the cir cuit for repeating in. one direction or the other, means to control the operation of the switching means according to the spacing or marking na ture of the current on one of the line sections when a signal is initiated, and means operative upon initiation of a signal in one line section to disconnect the winding associated with the other line section. 3. In a repeater system, a ?rst station, a sec ond station, a circuit connecting said stations, double wound relay means. to transmit informa "10 tion in both directions over the circuit, one of the windings of said relay means associated with from contact 61 have been shown as connected one line section and the other winding associated to a connector block 49 I. On any telegraph line, with the other line section, automatic means batteryis usually supplied at one end of the line comprising a pair of instrumentalities at each to ground. Itmay be desirable to provide bat tery from the distant station, so, to accomplish this result the conductor I62 and the ground lead and ground at the other, and the installer has speci?cations which, instruct him to strap certain terminals together. By means of the present in vention, it is only necessary to show different strapping on the connector block to indicate the different types of circuit. In Fig. 5, the. outlying stations are indicated as connected throughan exchange. 402. It is to be understood that various changes: and modi?cations may be made in the present inven tion without departing from the. spirit andscope thereof. station, one responsive to an. initial signal from said ?rst station and the other responsive to an initial signal from said second station to alter the transmitting means at each station variably at intervals according to which instrumentality re ceives the initial signal, and means operative upon initiation of a signal in one line section to disconnect the winding associated with the other line section. ' LOUIS M. POTTS.