US1330202A - Telephone-exchange system - Google Patents

Description

1. C. McAULlFFE.

TELEPHONE EXCHANGE SYSTEM.

APPLICATION FlLlD MAR-1,1918.

' Patented Feb. 10, 1920.

' improved signaling means for jvention;theincoming end of atrunk circuit 'o'usly to 'furn-islraguard signal, whichrev NITED STATES PATENT OFFICE.

'JoHno. MCAULIFFE, orinnw YORK, 1v. ASSIGNOR 'ro wnsrnnn'nnnormc 'ooMrANY, INCORPORATED, or NEwYonmn. Y., A CORPORATION on NEW YoiiK.

- TELEPHONE-EXCHANGE. SYSTEM.

T 0 all-whom it may concern:

Be it known that I, .Jonn O. MoAuL1rrn, a citizen'of the United States, residing at New York, in the county 01? 'New .York, State of New York,.have invented certain new and useful'lmprovements in Telephone- Exchange Systems, of which the following His-a full, clear, concise, and exactdescrip- .t i'on.

This invention relates to telephone exchange systems and more particularly to "such systems-employing trunk circuits for interconnecting telephone lines terminating at different switchboards.

The obj ect of this invention is to provide ln'accordancewith a feature of thisinis provided with ;a signaling device .which, when a link circuit is-connected with the "outgoing-end thereof,=is operated continumains so operated after "the trunk circuit has beenc'oiniectedwith a telephone lineuntil'the receiverthere'of isremovedifrom the switchhook to furnish a ringing'signahand which is intermittently operated to furnish a. disconnect signal when the link circuit is disconnected from the outgoing end of the trunk circuit.

For a linore complete understanding of.

this invention-reference should be had to the followingdescription considered in I 0911- V nection with "the accompanying, drawing illustratin'gone embodimentthereof. I

As shown in the drawing-a telephone line A terminates at oneeswitchboard where it, is

-'connected with a link-circuit B. A trunk circuit C- 'eXtends from the first to a second switchboard *and serves, whenithe llIlk circuit-B is connected therewith, to eXtendt-he position, whilelthat shown to the right of Kthisllineis associated with thesecond switch- .or' ..B,operators position.

." The;:subscriber.,Aehavingl aced ,a -a11- .ins the usual. manner vand. the cord circuit; B

such systems.

Specification of Letters Patent. Patented-Feb;10,1920. Application filed March 1,-1 91 s; Seria1 No.'219,786.

having beenconnected therewith, the P A operator may actuate listening key 6 to connect the operators telephone set with the telephone line. Upon being advised that subscriber A desires to be connected with the line which terminates at the second switchboard, the A operator restores the listening key 6 to normal position and communicates over an order wire circuit (not shown) with the FB operator of the. second switchboard and receives a trunk assign ment.

Assuming the trunk assignment ;to be trunk circuit 5G, the .A operatorinserts calling plug? of the cord circuit -B into jack 8'0f the'trunk circuit 'C, whereupon calling supervisory lamp 9 is lighted over a circuit from battery through the lamp :9, resistance '10, sleeve contacts of the plug 7 and the jack'S and resistance v11. to ground. Trunk relay 12 is also operated over a circuit from battery through the winding of calling supervisory .relay 13, ring contacts voflthe plug 7 and jack ,8, the windings" of the trunkrelay 12, and tip contactsof the jack 8 and the plug 7 to ground. LOalling V supervisory-relay 13 does not now operate vbecause of the high resistance of the lefthand winding of thetrunk relay 12. The

trunk; relay 12 in operating causes the lighting of lamp 15 and the operation of relay. 16. The lamp islighted over a circuitfromrbattery through the lamp .15, normal contact and lower winding of relay.1'7, and contact of thetrunk relay 12 toground. The lower winding of relay 17 is such that :therelay does not receive sufficient currentato cause it to open its-normal and closeits alternate contacts. Relay 16, in operating, .opensfits left-hand and closes its right-hand contact;

The lighting of thelamp'15 serves has an indication to the trunk or i B ,operatorthat the A. operatorhas connectedrwithzthe assigned trunk circuit. The B operator may thereupon insert plug 18. offthestrunk circuit Ginto jack 19.01? the ,telephonelline D, itbeing assumed .thatconnectionis desired with lZGlGPlIOIlGllllGiD. Upon the insertion of the plug.18. into the j ack..19,..relayl17 of the trunkzcircuit and 'cutofi' relay '20 of thetelephoneline are operated over a circuit from i battery .through t'theklamp .15,

upper winding ofrrelayl Iipsleeve contacts ofthe plug 18 and the ack 19 and the winding of the cutoff relay 20to ground. Relay 17 in operating opens its normal contact and closes its alternate contacts. The lamp 15 remains lighted. V V

Subscriber D may be signaled in any desired manner. Upon the removal of the re- Ceiver from the switch hook, supervisory relay 25 is operated over a circuit from bat-- tery through the winding ofrelay 25, ring contacts of the plug 18 and the jack 19, out over one side of the line, through the switchhook contact, back over the other side of the line, tip contacts of jack 19 and the plug 18, and the upper alternate contact of relay 17 to ground. Relay 25, in operating, connects the low resistance left-hand winding of relay '26 in parallel with thehigh resistance lefthand winding of trunk relay 12. A The resistance in circuit with the calling supervisory relay 13 is thereby reduced, permitting the operation of this relay. Relay-'13 in operating establishes a shunt circuit, including resistance 27, about the lamp 9 which is thereby eflaced. Relay 26operates, establishing a shunt circuit for the lamp 15, which may be traced from battery through the right-handcontact of relay 16, the righthand winding and the contact of relay 26,

lower alternate contact of relay 17. This shunt circuit is of low resistance, so that the lamp 15 is effaced.

At the conclusion of the conversation, subscriber- D, in restoring. the receiver to the switchhook, causes the release of relay 25, removingthe left-hand winding of relay 7 r 26 from parallel relation to the left-hand winding of trunk relay 12, thereby increasing the resistance in circuit with the calling supervisory relay 13. This supervisory relay 13 thereupon releases its armature, causing the calling supervisory lamp 9 to be lighted to furnish a disconnect signal. Subscriber A in restoring the receiver to the switchhook causes the lighting of the usual answering supervisory lamp (not shown). The lighted supervisory lamps of the cord circuit B serve as disconnect signals, whereupon the A operator may withdraw the plug 7 from the jack 8. Trunk relay 12 I thereupon releases, and in releasing opens the energizing circuit of relay 16. Relay 1 16 thereupon opens its right-hand contact,

which is in circuit with the relay 26. Re-

lay 26 thereupon releases its armature, opening the shunt clrcuit about the lamp 15. The

closure of the left-hand contact of relay 16- upon the release thereof, establishes aninter- I mittent shunt circuit for the lamp 15, which d may be traced from battery through inter- V rupter 28 and resistance 29, left'hand contact of relay 16 and the lower alternate contact of relay .17. The lamp 15 is thereupon intermittently lighted'to furnish a discon f nect signal to the "B operator, who may thereupon withdraw the plug 18 from the jack 19, restoring all apparatus to normal. condition.

From this brief description it will be clear that the lamp 15 is continuously lighted 1. A telephone exchange system:compris-- ing a trunk circuit extending from a first to a second switchboard, a telephone line terminating at a second switchboard and connected with the trunk circuit, allnk circuit at the first switchboard, a signaling device at the second "switchboard operating upon the connection of the link circuit therewith, a relay in the trunk circuit responsive to the closure of the telephone line upon the removal of the receiver from the switchhook for-stopping the operation of the signaling device, and a'relay responsive to the disconnection of the link circuit from the trunk circuit to cause the intermittent operation of the signaling device.

2.. A telephone exchange system comprising a trunk circuit extending from a first to a second switchboard, a telephone line terminating at asecond switchboard and connected with'the trunk circuit, a link circuit at the first switchboard, a signaling device at, the second switchboard operating .upon the connection of the link circuit therewith, a relay in the trunk circuit responsive to the closure of the telephone line upon the removal of. the receiver from the switchhook for stopping the'operation of the signaling device, and interrupter mechanism included in circuit. with the signaling device uponthe' disconnection of the link cir- 3. A telephone exchange system comprisinga trunk circuit extending from, a, first cuit from the trunk circuit to cause the intermittent operation ofthe signaling device.

to a second switchboard, a link circuit at the firstswitchboard, a telephone line terminating at the second switchboard, asignaling device in the trunk circuit, a relay in the trunk circuit energized in response to the connection of the link circuit therewith for causing the operation of the signalingcuit with. the telephone line, a relay "inthe trunkcircuit energized over the connected telephone line 'for controlling theYsignaL ing device, and an interruptermechanism' broughtinto'operative relation with thesig- 'nalm'g deviceby the deenergization of the evice, means for connecting the trunk cirfirst relay following the disconnection of the link circuit from the trunk circuit for causing the intermittent operation of the signaling device. 1

4:. A telephone exchange system comprising a trunk circuit extending from a first to a second switchboard, a telephone line terminating at the second switchboard, a link circuit at the first switchboard, a signaling device in the trunk circuit, a relay in the trunk circuit energized in response to the connection of the link circuit therewith, a second relay in the trunk circuit cooperating with the energized relay for causing the operation of thesignaling device, a circuit established by the connection of the trunk circuit with the telephone line for causing the energization of the second relay and for maintaining the signaling device operated, and an interrupter mechanism brought into operative relation with the signaling device by the denergization of the first relay following the disconnection of the link circuit from the trunk circuit for causing the intermittent operation of the signaling device.

In witness whereof, I hereunto subscribe my name this 16th day of February, A. D.

JOHN C. MOAULIFFE.

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