US1993855A - Telephone system - Google Patents

Description

March 12, 1935. 5. H. PETERSON TELEPHONE SYSTEM Filed Fep. 18, 1955' INVENTOR v G H PETERSON A TTORNEV Patented Mar. 12, 1935 UNITED STATES 1 F I E reclai s. (o1. 179-51 This invention relates to telephone systems and more particularly touniversal cor-d circuits for interconnecting telephone lines of like or unlike character. I

An object of the invention is to interconnect lines of like or unlike character and toprovide supervision for said connections,

A further object is to prevent fortuitous operation of the signals of said cord circuits.

A feature of the present invention whereby the foregoing objects are attained resides in interlocking relay circuits whereby-a plurality of relays will release simultaneously and circuit conditions conducive to false signal operation will be avoided.

Theinvention will be understood from the following description together with the accompanying drawing in which one embodiment-of myinvention is shown as applied to a universal cord circuit similar to that of 'Fig. 1 of the-application of H. W. Ulrich, Patent No. 1,904,017, issued April 18, 1933 which shows an arrangement for interconnecting magneto and common battery telephone lines. a I

V Circuit-description The present circuit is substantially'similar to that shown'in the above mentioned patent. A and B are two subscribers" common battery telephone stations and C and Dam two subscribers magneto telephone stations connected by tele-' phone lines with the central office wherein the lines'are terminated at a switchboard in multiple jacks. A line lamp is associated with one of-the jacks connected to each common battery line and a line drop is associated with one of the jacks connected to each magnetoline.

The universal cord circuit E is one of several situated at an operators position at a switchboard, any of which may beconnected to the operators telephone circuit F by the operation of the individual cord circuit talk'key, as for example key 106 in cord circuit We will assume that jack and associated line lamp 101, jack 102 andassociated line drop 103, jack 104 and jack 105 are located at the switchboard operators position with which cord circuitE and telephone circuit F are associated and that the other jacks and line signals are located elsewhere in the switchboard. I

Cord'circuit E-is provided'with answering and calling plug terminals 107 and 108, respectively. Answering and calling sleeve relays 109 and 110 operate in response to connections to common battery lines and connect talking battery I through the answering and calling supervisory relays 111 and 112, respectively, to the answering and the callingend of the cord talking conductors. Relays 111 and 112 control the answering and calling cord supervisory lamps 113 and 114, respec tively. i g V v Condensers 11 5 and 116 are inserted in the tip and: ring cord talking conductors, respectively, in order to prevent the passage of direct current, but to allow variable talking current to be freely transmitted.

Cord drop 117 is designed to operate on alter nating current from a subscribers magneto generator and is normally bridged from the tip conductor of the answering cord to the ring conduc: tor of thercalling cord. Relay109 in operating, with relay 110 unoperated, disconnects drop 117 from the tip of the answering cord and connects it between tip and ring conductors of the calling cord, while relay l10in operating with relay 109 unoperated, transfers the connection of drop 117 to the tip and ring conductors of the answering cord. With relays 109 and 110 both operated, however, drop 117 is entirely disconnected from both ends of thecord. v f My present invention is directed to the means for-preventing false operation of the drop 117 upon a disconnection of thecord E from common battery telephone lines. Upon a connection bee tween common battery lines Aand B, sleeve relays 109 and 1100f cord circuit E will both be operated as long as their respective connecting plugs are-inserted in jacks of the telephone lines. Upon disconnection, if calling cord plug 108 were re moved from its associated jack beforeanswering cord plug 107, and relay 110 were to release, drop 117 would be bridged across the talking conduc tors of the ,calling cord. This would create a charging path for condensers 115 and 116 from battery through thelower winding of answering supervisory relay 111, front contact of answering sleeve relay 109, condenser 116, back contact of calling sleeve relay 110, normalcontactof talk key 106, drop 117, front auxiliary contact of relay 109, back contact of relay 1'10, condenser 115, front contact of relay 109, upper Winding of relay 111 to ground. Drop 117 is liable to operateon the surge of charging current which would result. In accordance with the present invention, the answering and calling sleeve relays 109 and 110 have interlocking holding circuits whereby both relays will beheld operated upon connection between co-mmon battery lines until both connecting p u -1 108 a en-re ar ed ir m t jacks of the connected lines. The holding circuit comprises conductors 135 connected to the sleeve conductor of the answering cord, uppermost contacts of answering sleeve relay 109, conductor 136, normal contacts of talk key 106, conductor 137, uppermost contacts of calling sleeve relay 110, conductor 138 to the sleeve conductor of the calling cord. Upon both relays 109 and 110 being operated they are both held on circuits connected to ground on the sleeve of either the calling or called line. Upon removal of the second plug from its associated line jack both relays 109 and 110 will release simultaneously thereby avoiding the charging condition.

The operators telephone circuit F contains a transmitter 118 and receiver 119 and is provided with an arrangement for obtaining a click busy test upon both common battery and magneto lines.

Operation The operation of the circuit is as follows: 7

On a call from common battery station A the subscriber removes the receiver from the switchhook thereby closing the circuit from battery 125, through line lamp 101, contacts of jack 110, contacts of jack 126, through subscribers set A, contacts of jack 126, contacts of jack to ground 127, thereby causingline lamp 101 to light as a signal to the operator. The operator inserts the plug 107 of the answering cord in jack 100 thereby opening the normally closed contact of the jack and extinguishing line lamp 101, and connecting ground to the sleeve at the normally open contact 128. Relay 109 operates and cord supervisory lamp 113 may-light momentarily on current from battery in the cord circuit to ground on the jack sleeve. The operation of relay 109 connects ground and battery to the tip and ring of the cord through the winding of relay 111 operating this relay which opens the circuit for lamp 113. Relay 109 also disconnects the winding of drop 117 from the tip conductor of the answering cord and connects it fromthe tip to the ringof the calling cord.

The operator answers the callwith the talk key in the operated position. Now having a talking connection with the party at station A, the operator ascertains the number of the line desired by him. Assuming that the call is for common'battery station B, she thereupon performs a busy test in the usual manner and finding the line idle she inserts plug 108 in jack 104 thereby disconnecting line lamp 129 and the multiple jack from the talking conductors by opening the normally closed jack contact and connects ground to the jack sleeve at the normally open contact of the jack. Relay 110 operates and lamp 114 lights from battery in the cord circuit to ground on the sleeve of jack 104. The operation of relay 110 connects ground and battery through the winding of relay 112 to the tip and ring of the calling cord and opens the circuit for drop 117, disconnecting it from the cord.

The operator releases talk key 106 and operates ringing key 133 applying ringing current to the line and ringing the called subscriber. After a suitable ringing interval, she releases key 133. When the called subscriber answers, relay 112 operates extinguishing lamp 114.

At the completion of the conversation, subscriber B hangs up causing relay 112 to release thereby lighting lamp 114. When the subscriber at station A hangs up, relay 111 releases lighting lamp 113. I

The operator thereupon pulls down the calling cord terminating in plug 108. Calling sleeve relay 110 remains operated, however, a locking circuit being maintained for it from battery through its own winding and the previously described holding circuit to ground on the sleeve of the answering cord. If answering supervisory lamp 113 glows steadily, indicating a disconnect signal from the calling line, the operator pulls down the answering cord thereby removing. ground from the sleeve conductor and simultaneously releasing sleeve relays 109 and 110. If answering supervisory lamp 113 flashing, however, indicating that the calling subscriber is moving his switchhook up and down to signify a recall, the operator presses her talk key 106 connecting her telephone set to the cord, opening the holding circuit for calling sleeve relay 110 and opening the circuit through drop 117. This releases relay 110, but false operation of drop 117 cannot occur since the circuit through the drop is also opened at the talk key. The operator thereupon ascertains the number of the second line the calling subscriber desires and. proceeds as with an original call.

Assuming now that the call from common battery station A is for magneto station D, the operator makes a busy test on jack and finding the line idle, inserts plug 108 in jack 105 thereby disconnecting the multiple jack and line drop 130 from the talking conductors. On this connection the relay does not operate and lamp 114 does not light. Drop 117 remains in this case bridged across the tip and ring of the calling cord. The operator now rings in the usual manner and then listens until the called subscriber answers whereupon she releases talk key 106. I

When the subscriber at station B disconnects, he operates his hand generator 134 thereby applying alternating current to the line to operate drop 117 in the cord circuit. When the subscriber at station A disconnects, relay 111 releases and the cord supervisory lamp 113 lights as before. The operator after challenging on the call pulls down both plugs and manually restores drop 117.

On a call from magneto station C, the subscriber operates his magneto generator 131 which sends alternating current over the line through contacts of jacks 132 and 102 and through the winding of line drop 103 causing it to operate, giving a signal to the operator. The rest of the operation will be readily understood from the foregoing description taking into account the manner of operation of each end of the cord on magneto and common battery connections.

While the present invention is disclosed as embodied in certain specific arrangements, applicant does not wish to be limited by-such disclosure, but desires to cover broadly all arrangements that come within the spirit and scope of the appended claims.

What is claimed is:

1. In a signaling system, a signaling circuit, a signal receiving device normally connected to said circuit, asource of electric current, a pair of relays cooperatively acting when operated to disconnect said device from said circuit and individually acting when operated to connect said current source to said circuit, and locking means effective when both relays are operated to prevent one relay from releasing before the other.

2. Ina signaling system, a signaling circuit, a signal receiving device normally connected tosaid circuit, a source of electric current, a pair of relays cooperatively acting when operated to disconnect said device from said circuit and individually acting when operated to connect said current source to said circuit, and means to precircuit containing the current source to the talking conductors and to jointly disconnect said device from said conductors, said means being arranged to prevent reconnection of said device to the talking conductors before disconnection 'of the current source therefrom. i

4. In a telephone system, a pair of 'talling'conductors, a signal receiving device normally connected'across said conductors, a source of electric current, a pair of relays cooperatively acting when operated to disconnect said device from said conductors and individually acting when operated to connect said current source across 'said conductors, and locking means effective when both relays are operated to prevent one relay from releasing before the other.

5. In a telephone system, a pair of talking conductors, an electromagnetic signal, a circuit therefor normally bridged across said conductors, a circuit containing a source of electric current, a pair of relays cooperatively acting when operated to disconnect said device from said circuit and individually acting when operated to connect said current source to said circuit, and a common holding circuit for both said relays to prevent other than simultaneous release of the relays when both have been operated.

6. In a telephone system comprising lines of two different characters, a universal cord circuit for interconnecting any two of said lines, answering and calling connecting terminals for said cord circuit, tip and ring conductors connecting said terminals, an electromagnetic signal, a circuit therefor normally bridged across said conductors, a source of electric current, relays individual to each end of said cord circuit to bridge said current source across their respective ends when the associated connecting terminal is connected toa line of a first character, both of said relays cooperating to disconnect said electromagnetic signal circuit and means to prevent other than simultaneous release of said relays when both have been operated.

'7. In a telephone system, lines of two different characters, a universal cord circuit for interconnecting any two of said lines, answering and calljing connecting terminals for said circuit, tip and ring talking conductors connecting said terminals,

. sleeve relays operating to connect a source of potential between the tip and ring conductors of their respective ends of the cord when the associated terminal is connected to a first type of line, said relays cooperating to disconnect said signal controlling electromagnet, and means for locking both the sleeve relays operated in the same holding circuit.

8. In a telephone system comp-rising lines of a first and a second character, impulse sending means associated with lines of the second character, a universal cord circuit for interconnecting any two of the lines, answering and calling connecting terminals for said cord circuit, tip and ring conductors connecting said terminals, in-

ductive means included in each of said conductors, a supervisory signal for each'of the cords, an individual supervisoryrelay: for controlling each signal normally disconnected from said conductors, a current source in series with said relay, a signalcontrolling winding responsive to said impulse sending means normally connected between the tip conductor of one end .of the cord and the ring conductor of the other end, means responsive to the connection of either terminal to a line of the first character to connect its associated-relayto that end of the cordcircuit and to disconnect and transfer the impulse responsive winding fromthat end to the opposite end and responsive to the connection of both terminals to lines of the first character to'entirely disconnect said winding, and means-to prevent reconnection of the impulseresponsive winding before both said supervisory relays are disconnected.

9. In a telephone system comprising two types of lines, a universal cord circuit for interconnecting any two of said lines, answering and calling connecting terminals for said cord circuit, tip and ring conductors connecting said terminals, inductive means included in each of said conductors, a supervisory signal for each end of said cord, an individual supervisory relay for controlling each signal normally disconnected from said tip and ring conductors, a current source in series with each of said relays, a signal controlling winding normally connected between the tip conductor of one end of the cord and the ring conductor of the other end, a switching relay for each end of the cord responsive to the connection of its respective terminal to one type of line to connect the supervisory relay at that end of the cord across its tip and ring conductors and to transfer the connection of said signal controlling winding, to the opposite end, both of said switching relays cooperating to disconnect said signal controlling winding responsive to the connection of both terminals to said type of line, and means to prevent other than simultaneous release of said switching relays when both are operated.

10. In a telephone system comprising magneto and common battery lines, a universal cord circuit for interconnecting any two of said lines, answering and calling connecting terminals for said cord circuit, tip and ring conductors connecting said terminals, inductive means included in each of said conductors, a supervisory signal for each end of said cord, an individual supervisory relay for controlling each signal normally disconnected from said tip and ring conductors, a current source in series with each of said relays, a signal controlling winding normally connected between the tip conductor of one end of the cord and the ring conductor of the other end, a switching relay for each end of the cord responsive to the connection of its respective terminal to a. common battery line to connect the supervisory relay at that end of the cord acrossthe tip and ring conductors and to transfer the connection of said signal controlling winding to the opposite end, both of said switching relays cooperating to disconnect said signal controlling winding responsive to the connection of both terminals to common battery lines, and means to prevent other than simultaneous release of said switching relays when both are operated.

11. In a telephone system comprising two types of lines, a universal cord circuit for incircuit, tip and ring conductors connecting'said terminals, inductive means included in each of said conductors, a supervisory signal for each end of said cord, an individual supervisory relay for controlling each signal normally disconnected from said tip and ring conductors, a current source in series with each of said relays, a third supervisory signal, a controlling winding therefor normally connected between the tip conductor of one end of the cord and the ring conductor of the other end, a switching relay for each end of the cord responsive to the connection of its respective terminal to one type of line to connect the supervisory relay at that end of the cord across its tip and ring conductors to transfer the connection of said third signal controlling winding to the opposite end, both said switching relays cooperating to disconnect said third signal controlling winding responsive to the connection of both terminals to said type of line, and means to prevent other than simultaneous release of said switching relays when both are operated.

12. In a telephone system, common battery and magneto telephone lines, a circuit adapted to be included in a connection between both types of lines, a current responsive device normally connected to said circuit, a direct current source normally disconnected from said circuit, and dual means responsive to connection of said circuit to a pair of common battery lines to individually connect said source to the circuit and to jointly disconnect said device therefrom, said means being arranged to prevent reconnection of said device to the circuit until said source is disconnected therefrom.

GEORGE H. PETERSON.

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