US1431865A - Cable telegraphy - Google Patents

Description

H..ANGEL CABLE TELEGRAPHY.

APPLICAION FILED JUNE 7, 1919.

Paented Oct ll, i922.

2 SHEETSSHEET l.

QN MN mi EN www H. ANGEL CABLE TELEGBAPHY.

APPLICATION MEO Juni 1. i919.

2 SHEETS-SHEEI 2.

@Imi/614m d Patented @et lll, T922.

NETE@ STATE@ retenir HERBERT ANGEL, 0F BROOKLYN, NEW YORK,A ASSG-NOR TO THE UNION TELEGRAPH COMPANY, 0F NEW YORK, N. Y., A COBEORATION 0F NEW YORK.

CABLE mantenerse".

. Application led June 7, 1919.

To all/whom it may concern.'

Be it known that I, HERBERT ANGEL, a subject of the United Kingdom" ot' Great Britain and ireland, residing at Brooklyn, in the county of Kings and State of New York, have invented certa-in new and useful lmprovemeiits in Cable Telegraphy, of which the following is a specification.

This invention relates to a method of and apparatus for operating-cable or ocean telegrapliy wherein the code' signals' are sent into `the cable automatically by a tape transmitter and at the receiving end are selectively transmitted to the actuating magnets of a printinvr telegraph apparatus.

Ocean cabkle operation, as at present practiced, re uires the received messages to be translate `by an operator, and may, therefore, be considered as semi-automatic, whereas on land lines both the`transmission. and receiving of messages is entirely automatic', the messages being translatedpanel recorded by means of an electrically operated telegraphic printer, the more important lines being operated onthe multiplex system employing. a sending and receiving distributor operating synchronously at each end of the line.

One of the purposes of my invention is to provide a method of ocean cable operation employing thev` .fundamental principles or" the multiplex system on land lines; whereby the code characters may be automatically transmitted and received rapidly and accu-y rately. A further object is to provide an automatic system of ocean telegraphy especially adapted for the employment of threeunit code characters, which is the minimum number of impulses that can be used for each character.

It is well known that reversed current impulses sentf rapidly through a long submarine cable are the most clearly defined at the distant en'd of the cable since each tollowing current has the 'effect of neutralizing the preceding one. This principle 1nay.be utilized when a tive-unit code is employed if succeeding impulses of like sign are suppressed in 'the transmission and are then r introduced at theI receiving end. On the other hand, while in the three-unit code certain of the characters require succeeding current impulses of like sign or polarity, yet the time required to transmit a char- Selial lilo. 302,429.

acter of three impulses is only three-fifths of that required for a five-unit character and consequently the time period for each impulse may be lengthened somewhat and still permit a more rapid transmission of the code characters.v ln this manner the wave distortion due to the cumulative eect of succeeding impulses of like sign. may be minimized, especially if the cable is grounded for an. instant between succeeding impulses. tween successive impulses o1 i rendered unnecessary when the method of cable operation disclosed in U. S. apnlicanon of Josepaw. minor, sei-isi ne'. @54,401 is employed. i l

l have found that the distortion of the -wave form of the impulse transmitted lays which transmit the current impulses to the recording device or printer, sh all be connected only during the intermediate portion ot' each current impulse. This results in a clear definition of the positive and negative character impulses. l also provid(` lier the groundingv ot' the cable 'for an instant bctween successive impulses to minimize or nullify the cumulative effect oij successive impulses of like sign, ln order that this invention may be clearly understood and properly carried into effect it will now be described with reference to the accompanying drawings. in which- Figure l is a diagram illustrating one form of apparatus which may be employed; l? i2 is chart showing the posi H negative and zero impulses correspondutto each vletter and character of tl three-unit code; and Fig, 3 is a plan. view a s it' t "in perforated to indicate the charac. code.

ln the diagram the ground connections at either end of the cable and the arrangement The necessitycfor grounding belre sign is rs theA be installed ateachf end of the cable for duplex or multiplex operation.

The method of sending a signal or combination of signals is similar to that in theI multiplex system. A transmitting tape 1s' to indicate the characters Qt lirst perforated means of a keyboardV perfothe message by rator adapted or the three-'unit code.

4perforated tape is then fed through the tionaryfcontacts-c,

of the selecting pins of the transmitter (not transmitter, advancing the space of one character for each revolution of the sending distributer.

The automatic transmitter, indicated diaV grammatically at T, is of the well-known type,'such as described in U. 1,298,440 'rantedf to Gr. R. Benjamin March 25, 1919. t:ln the transmitter as modified for use in the three-unit code system, the stationary contacts are arranged in two groups a, b of three connected against the back stops 14. When a tape is fedthrough the transmitter, one, two or .three of the movable' contacts will be moved into contact with the corresponding stab, depending upon which in alignment with perforations shown) are as is understood by those famillar in the tape,

with transmitters of this type. It, however,

a blank space isfed through the transmitter, no contacts will be made. The movable contacts are electrically connected in pairs, the minus and plus contacts of each of the three positions being thus connected. The combinations of minus, plus and zero im ulses of the code characters are so arrange that only one movable` contact of each pair can "be moved for any code character, i. e. if the negative contact of one of the three positions is moved, the corresponding positive contact will not be moved because the tape Willnever be punched on the positive and negative sidesl with perforations corresponding to the same position. Each pair of movable contacts is connected with one of the contacts 15, 15" and 15c of the distributer D. After the current impulses corresponding to code character perforations on the tape have been transmitted in sequence to the transmitting relays by the rotation of the brushes on the distributer, a current is transmitted through the contact 18 on the distributer to actuate the transmitter magnet 17, which operates to retract the movable contacts 12, 12

The

plain S. Patent No.v

contacts, each connected respectively to the negative and posi.-V

against their backstops 14, and simultaneously move the tape forward to bring the next set of perforations opposite the selecting`pins of the transmitter.

he .rotary distributer D which connects the contacts of the transmitter T with transmitting relaysTR, TR', operates synchronously with the corresponding distributer D at the receiving station, the segmented and contact rings being shown for convenience in the developed form. The plain or continuous rings R1, R2, R3 are connected by the rotating brushes BRI, BR2, 'BRS with the segmented rings S1 S2 and S,.respectively. The rings S, and S3 are shown as having fifteen segments each, while. the rin S1 is provided with thirty segments.

The rushes may be' assumed to be in horizontal alignment and to move simultane ously. As the` brush BR2 engages .the first segment of ringS2v it connects the minus and plus contacts 1 'jhrough the contact block 15a with' ring R2 which isin circuit with the coils 20,v 20 of the transmitter relays, the return conductor 25 being connected to the intermediate or neutral point in the potentiomete coil 26, across the bus bars 8, 9. Consequently, if at this instant the minus 1 Contact. of the transmitter is in contact with the minus bar (L a minusor negative current will flow through the relay coils 20, 20, causing the armature tongue of relay TR to A swing overvagainst the righthand contact'- while the tongue of the relay TR remains against the left hand contact since its coil is connected reversely. This movement of the tongue of relay TR causes a negative current to be sent into the cable from the cable battery 30. In order that the impulse may be prolonged after the brush BR2 leaves the two segments-connected by the contact 15, the brush BRrloses a circuit through the battery 30 and the locking coils 31, 31', of the relays, thereby causing the ton e of TR toremain against the right han contacit While the brush BR1 is passing over the segments ofring S1 which are connected by contact blocks 16a.

The tongues of the relays TR and TRl` are normally held against the vleft hand contacts under the pull-of the coils 23, 23 which are constantl weaker than either el, the other coils. As soon, therefore, as the brush BR1 leaves the last segment of ring S1 connected to contact block 16, thereby breaking the circuit through coils 31, 31, the tongue `of rela TR will swing back against the left han contact so that the cable Will again be grounded through the tongues of the two relays.

When the brush BR2 passes over the segment for ring S2 connected to contact energized but are' block 15", the minus and plus contacts 2 of the transmitter T will be connected with l positive currentj Will How therethrough if the minus contact or the plus contact of the transmitter is against the .corresponding block a. or b. lf, however, there Was no perforation of the tape 'corresponding with the position 2, no current will flow through -vthe relay coils and their tongues Will remain against the left hand contacts.

-The cable Will, therefore, remain grounded forv this second position, or as it is usually termed, zero current will be transmitted to the cable.

When the brush BR, passes over the seg,- ment of ring S2 connected to contact block 15, the minus and plus contacts 3 of the transmitter will be connected in circuit with the relay coils 20, 20. lf the plus contact is in contact With the transmitter bar at this instant, a positive current impulse will flow through the lcoils 20, 20 and the tongue of relay TR Willmove over against the right hand contact, thereby causing a positive current impulse to be sen't through the cable from battery 30. As the brush BR, passes over the segments ot ring S, connected to contact block 16 a circuit will be closed through the lockin coils 3l, 31 to hold the tongue ci relay f R to Ward the right iur a period after the brush BR, left the segments of ring S2 connected with contact block 15,Athereby prolonging the current impulse sent into the cable. During this interval when the last impulse is l being sent into the cable, the brush BRZ, contacts with' contact block 18 of the segment kring S3 thereby energizing transmitter magnet 17, which actuates the transmitter, causing the movable contacts toshitt against their back stops 14, and

simultaneously moving the tape forward to bring the next succeeding set of perforations into alignment with the transmitter selecting pins. 'The latter immediately enter the periorations of the tape thereby causing thecorresponding minus and plus contacts to move over into contact with the transmitter bars a, b, in readiness to transmit current impulsesto the transmitting relays as the brushes of the` distributer again ln the diagram l have shown the rings1 divided into thirty segments, that is, ten for each of the three impulses of a code character, and six segments of each group are connected or strappedtogether by means of the contact blocks 16, 16b and l6,.respec time allotted to an impulse and if ten blocks are connected together, the impulses Will occupy 100% of the time allotted toan impulse and there would then be no interval between the separate impulses of a code character.' This adjustment of the number of parts of each contact block forms a very convenient method of` determining the length of the impulses of the code charac-f ters.

Consider now the operation of the apparatus at, the receiving end of the cable. The cable relay CR swings against one contact 'orthe other in response to the positive and negative current impulses and remains in unoperated position when the current is Zero. Thel relays Ru, Rb, .are normally biased against their left hand back stops in any suitable manner, and are energized from the battery L.t0 in res onse to the movements of the relay QR. T ey are very sensitive and operate quickly and with precision the instant a circuit is closed through battery 4:0 by the cable relay; y

The control relays C and CL which transmit ,the positive and negative impulses respectively to the selecting relays through the distributer D are' preferably provided with biasingI coils 42, 42 through which a kWeak current constantly flows to normall bias the armature tongues against the le hand back stops.

As previousy stated, the distributors at the sendin and receivin stations are o erated. in synchronism by synchronizing and phase correcting apparatus such as disclosed armature tongue to swing over against its i'ront contact as indicated in dotted lines. A current' `will flow from battery 41 throufrh the back stop and tongue of relay n, through. the coils 43, 43 of relays C and CL", and return to battery through the front i contact ,fand tongue of relay Rb. The coils of relays CL 'and CL) are reversely connected so that the current thus impressed Will cause the tongue of relay CL (which Jresponds to minus or negative impulses) to swing over against its front stop, as indicated' in dotted lines. A minus current will `thenl be sent from battery 50 through the actuating coils of selecting relays 7, and 1, as the brush Biti passes over the segment of ring S4 connected at 15a' to the conductor connected to the coils of said selecting relays. inasmuch laol as the coils of the selecting relays 1', and r, are reversely connected, only the tongue of relay r1 which responds to minus impulses, will be operated.

' The receiving segments l5, l5b and 15- of the segmented ring S, of the distributer D are much narrower than the' corresponding segments of rings S1 and S2 of the distributer" D at the sending station, since a current impulse of very short duration from the local battery or generator 50 is sucient to actuate tlie selecting relays. Furthermore, these receiving segments of ring S4 are so arranged with respect to the transmitting segments of rings S1 and S2 that the impulses transmitted to the selecting relays occupy an intermediate part of the time interval of the transmitted signal current. The marking impulse transmitted by the distributer at the receiving station therefore occurs when the transmitted current impulse circuit is closed at its front or Waveihas reached its most steady and accurate form, since the variations and inaccuracies occur mainly during the first and last parts of the current wave.

In order that the armature tongues of the lselecting relays shall remain in their operated positions, after the brushes of the distributer D have moved oit of the corresponding segments, so that the entire code character may be set up en the selecting magnets and to provide for an dyerlapnn order that the printer operation may take; place at the same time that the impulses r the succeeding code character are beingl received, -the selecting relays are provide with locking coils in the circuit leading to the translator magnetsA which is closed through the ton es oi4 the relays and the front contacts. his holding or locking circuit is maintained throu hthe armature of the clear-out rela 45 until the latter is energized as the distri liter brush BR, passes over the segment of rin S, comiected to contact block 19. As the oclring circuit is broken at the back stop of the clear out relay, a stop through the printing pulse magnet 46. 1

The foregoing detailed description of the manner of operatingmy system of ocean telegraphy adapted or use with three-unit code characters will make clear to engineers the advantages which this system ossesses over prior methods of operating cab es. ot only is both the transmission and receiving of messages made entirely automatic. but the time required for the transmission `is materially shortened which is a very important factor in the commercial operation of cable telegranhy. Moreover, the marking intervals occupy only a portion of the. time interval of the transmitted signal impulses, Ithus providing larger intervals for lcharacteristic irregularities in cable signalling and for the operation of the synchronizing and merece phase correcting devieesand thereby contributing'to greatera'ccuracyin the opera-- tion of the system.

I claim 'v1'. A synchronous telegraph system' wherein the code signals are automatically transmitted and received, comprisinga tapecontrolled transmitter, apair'oii transmitting relays operating respectively to connect the line or cable with the positive or negativepole of an electric source7 anda distributer having segments connected to contarts ot' said transmitter and connected in sequence to the coils of said relays, said segments being less in number than said contacts.

2 A synchronous telegraph system as set forth in claim 1, each of said distributer segments being connected to a plurality of said transmitter contacts.

A synchronous telegraph system wherein the code signals are automatically transmitted and received, comprising an automatic tape-controlled transmitter:transmitting relays operating respectively to connect the line or cable with the positive or negative pole of an electric source, a distributer provided with segmented members having elements connected to said transmitter and successively connected in circuit with the coils of all of said relays` and means for maintaining said relays in operated position for a predetermined period after the transmitter has been disconnected therefrom.

4. A synchronous telegraph system Whereinthe code signals are automatically transmitted and received, comprising Ian Iaiitomatic tape-controlled transmitter, transmitting relays operating respectively to connect the linepor cable with the positive or negative pole'of an electric source', a distributer provided with segmentscpnnected to said transmitter and successive] connected in circuit with the coils of saidY relays, vand an additional segmented member on. said distributer having segments connected to hold-` the current impulse transmittedito the cable.

5; A'n automatic telegraphl system, comprising synchronously operated current distributers at the transmitting and receiving stations, a pair of relays interposed between the distributers and the cable., a tape-controlled transmitter having conn'ected pairs of contacts, the members of each pair cooperating respectively with contacts connected to opposite oles of an electric source, and a pair of se ectiii relays arranged in reversely connected pa positive or negative impulses /to the translator magnets of a, printer, theT distribiiters through the holding coil of the actuated relay to prolong ice llO

rs and adapted'to transmit A 1,43 pees having active segments equal only-to the number of pairs of transmitter contacts.

6. A synchronous telegraph system Wherein the code signals are automatically transmitted and'received. comprising an automatic tape-controlled transmitter, a pair of transmitting` relays respectively operating to connect the line or cable with the positive or negative pole of an electric generator, a distributer provided with segmented mem'- bers having elements connected to said transmitter and successively connected in circuit with the coils of said maintaining said relays in qperated positio for a predetermined period after the transmitter has been disconnected therefrom` receiving apparatus comprising' a cable relay and auxiliary relays operating respectively to transmit positive and negativeimpulses, a pair of selecting relays arranged in reversely connected pairs, operating to transmit respectively positive or negative impulses to thc translator magnets oi'aprinter, and a distributer operating synchronously with the irst-named distributer to connect said auxiliary relays to said selecting relays for shorter time intervals than said transmitting relays are connected to the cable.

7. A telegraph system wherein the cable signals are automatically transmitted an'd received, comprising synchronously operated current distributers at the transmitting and receiving.,r stations, a .pair of relays interposed between the distributers and the cable, and means for prolonging the current impulses transmitted to the cable a pre determined interval after the termination oi the operating impulse from the distributor to the relay. I

8. A telegraph system wherein the cable signals are automatically' transmitted relays, means for the distributer at the receiving station to oocupy only an intermediate portion o1P the intlval of the corresponding transmitted signal.

9. A synchronous telegraph system wherein theasignals are automatically transmitted and recorded and the code charactersl are composed of combinations of positive, negative and zero current impulses, comprising -an automatic tape-controlled transmitter having' sets of stationary contacts directly connected respectively to the positive and negative poles of a generator, a plurality of pairs of connected contacts movable individually into contact with said stationary contacts under the control of the perforated characters in the tape, a distributer having segmented members separated elements of which are connected in sequence to said pairs of movable contacts, a pair of relays corresponding respectively to positive and negative current impulses, and operating to connect the cable with corresponding poles of a. generator, and brushes movable over the members of said distributer and operating` to connect the actuating coils of the relays successively with said separated elements.

In testimony whereof, I aix my signature.

HERBERTV wenn

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