US1648922A

US1648922A - Printing-telegraph system

Info

Publication number: US1648922A
Application number: US95066A
Authority: US
Inventors: Gilbert S Vernam
Original assignee: American Telephone and Telegraph Co Inc
Current assignee: AT&T Corp
Priority date: 1926-03-16
Filing date: 1926-03-16
Publication date: 1927-11-15
Anticipated expiration: 1944-11-15

Description

Nov. 15, 1927. 1,648,922

' G. s. vx-:RNAM

PRI NTING TELEGRAPH SYSTEM Patented Nov. 15,v 1927.

uNrrEn4 STATES PATENT oEEicE.

GILBERT'SJVERNAM, 0F RIVER EDGE, NEW JERSEY, ASSIGNOR TO AMERICAN TELE- PHONE AN D TELEGRAPH COMPANY, A CORPORATION OF NEW YORK.

PRINTING-TELEGRAPH SYSTEM.

Application led March 16, 1926. Serial No. 95,066.-

This invention relates to printing telegraph exchange systems, and more especially to such of those systems wherein the power supply at the subscribers stations is controlled from a .distant central olice.

The object of this invention is to reduce to a minimum the current required and the maintenance expense incurred in the operation of a printing telegraph 'system which may be employed to interconnect, through a centralOiCe, sta-tions requiring light duty service, particularly, those stations whereat printing sets are idle for a considerable part of the time during which it is Adesired to have no parts in motion.

In accordance with this invention, the

ymotors at the calling and called stations are not started until a set of impulses consti!- tuting a character, is received from the operator at a `central switching station.

The above and other features of this in-l vention are set forth in the -tollowing description and appended claims, and may be more readily| understood when the description is taken in conjunction with the accon1' 'panying drawing which yillustrates this invention. In the drawing `there is shown a complete telegraph printing system consisting of'a central ollice with two snbscribers stations with only that apparatus necessary for a clear understanding of the invention.

Referring now to the drawing, there are shown two printing telegraph subscribers stations, A -and B, having telegraph lines,r I) and E, respectively, connecting the stations with a central switching station C. It will be understood, of course, that in actual practice many otherlines, similar .to D and E, may terminate at t-he same central station and that a plurality of link, or cord circuits, similar to the one shown, are employed. Each of the link circuits is arranged with a polar relay repeater consisting of

relays

1, 2, 3 and 4for repeating d1- rectl the impulses received from one line to anot ier with which it is associated through the link circuit. For a more complete understanding of the operation of the repeater, reference is made to the patent to J. M. Fell No.'1,479,430, issued January 1, 1924. Lines D and E each consists of t e usual pair of wires, one wire with a ground return being used for the `transmission of the message impulses, and the other being available for con- 6, ring contact of jack 7, cont-rol wire 8 of fline D, switch 5 (normally closed), through the right-hand winding of control relay 9 to ground.` Relay 6 deenergizes and releases itsl armature to close an obvious energizing 'circuit for the line lamp 10. Line lamp 10 is thereupon lighted for indicating to the operator that subscriber Afdesires to be connected with another subscriber.

` The operator at the central station, in observing the lighted condition of lamp 10, inserts answering plug 11 in jack 7, whereupon the energizing circuit of the lamp is opened by the re-energization of relay 6. The circuit for the re-energization of relay 6 may be traced from grounded battery, through the winding of relay 12, conductor 13, sleeve of jack 7, through the right-hand winding of relay 6 to ground. In the latter circuit relay 12 operates to close a circuit extending from grounded battery, innermost contact ot' relay 12, contact'14, line 'windings 18 and 19, respectively, of-` relays 1 and 2, tip contact of jack 7, ywire 26 lot' line l), transmitter 27, through the winding of printer magnet 28, through the left.

hand winding of control relay 9, to ground, to hold relay 9 in an operated condition, this relay having previously operated, until it is desirous'to start the motor at station A. Relay 12, in operating, closes at the next to its innermost contact a circuit extending from grounded battery at the outer right `normal contact of key 35, contact of relay 12, contact 16 of relay l, line windings 2O and 21, respectively, of relays 3 and 4, to

,ground at the armature of relay 29. Also,

at the outermost contact of relay 12 an obi vious circuit isclosed for energizing the

local windings

22 and 23, respective y, of relays 2 and 1, andlocal windings 24 and 25, respectively, of relays 4 and 3. The circuit for energizing these local windings contacts. During the time'that the plug 1l is`in jack 7, and`no message signals are bee ing transmitted, the current conditions in theline and the local windingsof the repeater are such as to mamtain the contacts 14, 15, 16 and 17 in closed positions, and it is only when the current passing through ythe lineywindin'gs isyaried or stopped by may be found in the above mentioned Fell "winding of printer magnet 45, through the the operation of a transmitter at the sending station that these contacts are opened. `Avniore `complete description of the operation of the 'repeater as hereinbefore stated Patent No. 1,479,430.

The plug 11 having been inserted in jack 7, the operator is now in'connection with subscriber A. The operator-thereupon actuates a 4printer-key 35 which vconnects the operators printing telegraph equipment to the selected link. u opens a normally closed circuit extending from grounded battery at the operators transmitter 36, through the Winding of printer magnet 37, inner right normal contact of the key, through the winding of control relay 38, to ground. Relay 38 deenergizes and the motor 47 for the operators telegraph equipment is started.,

The operator than transmits a character signal to the subscriber A, which eilfects the momentary opening of contact 14. l/Vhen contact 14 is opened, the circuit extending through the left-hand winding of control relay 9 as hereinbefore traced, is deenergized. lnasmuch `as the circuit extending through the right-hand winding of relay 9 is opened at switch 5, relay 9 releases its armatures and a. circuit is closed at the right armaturefor starting the. motor 39.I

1n this manner the motor 39 at the subscribers station is lnot started until the first character signal is transmitted by the operator.r At the left armature of relay 9 a substitute ground is provided for preventing the subsequent energization of relay 9 when contact 14 closes during the transmission of message impulses.

Upon receiving the character signals from the operator, the subscriber A now operates transmitter v27 to send a character signal to the central station indicating to the operator that a connection is desired with line E extending to subscribers station B. The operator, having ascertained the number of The operation of key 35' -to the call, and closes an energizingcircuit for relay 29 which operates to connect the.

lline-'windings 20 and 21, respectively, `ot relays .3 and 4, with the tip conductor of plug 40.

The insertion of plug 40 in jack 41 also opens.two normally closed circuits extend' mg, respectively, through both windings of control relay 43 but this relay is main-1 tained energized by :the substitute battery supply at transmitter 36, the substitute cir- Kcuit being traceable from transmitter 36,

through the winding of magnet 37, offnormal contact of key 35, next to the innermost contact of relay4 12,l contact 16, line windings 20 and 21, respectively, of relays 3 and 4. front conta-ct of relay 29, tip contact of jack 41, transmitter 44, through the right-'hand winding of relay 43, to. ground. rlhe operator then transmits a character Vsignal to Asubscriber B, and the lastl traced circuit is opened momentarily at transmitter 36, causing the deenergization of the righthand winding of relay 43, and the relay releases., The release of relay 43 closes a circuit extending through the motor 46 at station B and the motor starts. The character signal transmitted to station B by the operator is also receivedA by the subscriber at station A indicating to the subscriber at that station that he may proceed with the message.

The operator then restores the printer key 35, which transfers the battery supply at transmitter 36 from the line circuit extend ing to station B, to the circuit extending through the winding of relay 38. Relay 38 re-energizes, thereby opening the circuit extending through motor 47 and the motor stops. `When the battery supply at transmitter- 36 is removed from the line circuit, another battery supply is substituted at the make-before-break cont-act of key 35 to maintainl the line circuit extending to station B, as hereinbefore traced, closed while awaiting the transmission of the message from station A. Key 35 when restored, connects battery at its left contact to prepare a circuit extendingithrough supervisory lamp 48, over the ring contact of jack 7 and control wire 8 to the open switch 5. r1`he transmitter at station A is now connected through a repeater at station C to the printing equipment at station B. A

At the completion of the messae the subscriber at station A restores switch 5 and the circuit which was prepared by the restoration of printer key 35', mentioned above,

is closed. This circuit may be traced from grounded battery, left contact of key 35, supervisory lamp 48, ring contact of Jack 7, control wire 8, switch 5, right-haiid winding of relay 9, to ground. Relay 9 operates and opens the energizing circuit for motor 39, thereby bringing the motor to a stop. The lamp 48 is lighted in this circuit and thereby informs the operator that the message 1s completed and that the answering and calling plugs may be removed from their respectively associated jacks. The removal of the plugs places t-he apparatus at the two subscribers stations and that associated with the operators link circuit which was employed in the connection, in normal condition.

W'liat is claimed is:

l. A printingtelegrapli exchange s stem comprising a central station, a plurality of subscribers stations, a plurality of telegraph subscribers lines `interconnecting said central station and said subscribers stations, manually operable link circuits at said cen tral station for interconnecting said subscribers stations, means at each of said stations for transmitting and receiving impulses, and means at said central station for preventing the operation of the transmitting and receiving means at 'any of said subscribers .stations until the operation of the transmitting means at the central station.

2. A printing telegraph exchange system comprising a central station, a plurality of subscribers stations, a plurality of lines interconnecting said central station and said subscribers stations, manually operable link circuits at said central station for interconnecting said subscribers stations, means at each of said stations for transmitting and receiving impulses, and individual motor means for driving each of said transmitting and receiving means, arranged to be normally idle` said motor means being under 'the control of the transmitting means at the central oflice.

3. A printing telegraph exchange system comprising a central'station, a plurality of subscribers stations, a plurality of lines interconnecting said central station and said subscribers stations,imanually operable link circuits at said central station for interconnecting 'said subscribers stations, means at each of said stations for transmitting and4 receiving impulses, a. plurality of signals kat said central station, common means at'each of said subscribers` stations for operating said signals, one signal being operated when a connection with one of Vsaid link circuits is desired and the other when said connection should be discontinued, an electrical motor for driving each of said transmitting` and receiving means, arranged to be starte by the operation of the transmitting means at said central station and arranged to be stopped when said common .signaling means is operated to discontinue said C onn'ection between the line and the link circuits.

4. A printing telegraph exchange system,

comprising a` central station, a plurality of subscribers stations, calling and called lines for connecting said central station with said subscribers stations, manually yoperable links at said central station for interconnecting. said callingand called lines, means at each' of said stations for transmitting and receiving impulses, a plurality of signals at said central station, common means at subscribers stations of each of said calling lines for operating said signals, one signal being operated when a connection with one of said link circuits is desired andthe other when said connection should be` discontinued, start-stop motor means associated lwith each of said transmitting and receiving means arranged to be normally idle, means at `said central oice for starting the motor thereat to drive its associated transmitting and receiving means,` said transmitting means at the central otlice effecting the starting ozt'the motors at the subscribers stations of botli the calling and called lines, and 'means at the central station for stopping the motor thereat when the subscribers atthe stations of the calling and called lines are in intercominunication. m

5. A printing telegraph exchange system comprising a central station, a plurality of subscribers stations of each of said calling lines for operating said signals, one signal being operated when a connection with one of said link circuits is desired and the other when said connection should be discontinued, start-.stop motor means associated with each of said transmitting and receiving means arranged to be normally idle, means at said central station for starting the motor thereat to drive its associated transmitting and receiving means', said transmitting means at the central office effecting the starting of the motors at the subscribers stations of both the calling and called lines, and means at the'central station for stopping the motor tliereat when the subscribers at the stations of the calling and called lines are in intercommunication, the motors at the subscribers stations o'f the calling and called lines being stopped at the completion of the intercommunication when said connection is discontinued upon the operation of the second mentioned signal.

6. A printing telegraph exchange system comprising a central" station, a plurality of subscribers stations, a plurality 'of telegraph subscribers linesA interconnecting said vcentral station and said subscribers stations, link -circuits at Said central station for interconnecting said subscribers stations, a central office repeater forrepeating signals 'from .one line to another, means at each of saidl stations for transmitting and receiving character signals, and a motor at each of said stations for driving said means, the `motors at the Subscribers stations beingarranged to he started when a character impulse is transmitted from the central station.

72A printing telegraph excliange'system comprisnug a central station, a vplurality of subscribers stations, a plurality of telegraph subscribers lines interconnecting said central station and said subscribers stations,-

link circuits at said' .central station for interconnecting said subscribers stations, a polarized repeater in each of said link circuits .for repeatingI signals from"y one line to another, means at each of saidstations for transmitting and receiving character signals, and a motor at each of said stations for driving said means,"the starting and ,stop-" ping of the motors at, the subscribers sta.- tions being directly controlled from the central oiiice. v A

In testimony whereof, I have signed my name to this specification this 13th day of March, 1926.

GILBERT S. VERNAM.