US1448523A - Telephone-exchange system - Google Patents

Description

Mans, 1923.

//4 van for. RoyD, Conway R. D. CONWAY. TELEPHONE EXCHANGE SYSTEM- FILED OCT 23.1911;

Patented Mar. 13 i92 UhllTitllO tan arisen ROY D. CONWAY, OF CHATHAM, NEW JERSEY, ASSIGNOB TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

TELEPHONE-EXCHANGE SYSTEM.

Application filed October 23, 1918.

To all whom it may concern.

Be it known that I, ROY D. CONWAY, a citizen of the United States, residing at Chat-ham, in the county of Morris, State of New Jersey, have invented certain new and useful Improvements in Telephone-E); change Systems, of which the following is a full, clear, concise, and exact description.

This invention relates to telephone ex change systems and more particularly to telephone circuits incoming to telephone switchboards at which are cooperating-circuits for extending such incoming circuits.

The object of this invention is to provide improved signaling means for systems of this character.

In accordance with a feature of this invention, a trunk circuit incoming to one switchboard and having an electromagnetic switching device for controlling a signal associated therewith, is also provided with an electromagnetic relay which cooperates with the electromagnetic switching device when an extension circuit is connected with the trunk circuit to control the operation of a signaling device in the extension circuit.

In accordance with another feature of this invention, a trunk circuit is provided with two electro-magnetic relays, one of which controls a signaling device in. a con-- nected extension circuit when a switching device associated therewith is in one position, and when the switching device is in its other position the other relay of the trunk circuit controls the extension circuit signal ing device.

In accordance with another feature of this invention a signaling device of an exten sion circuit when a switching device thereof is in one position, is controlled by a relay of the trunk circuit which operates over a portion of the talking circuit of the connected extension and trunk circuits, and when the switching device is in its other position the signaling device is then controlled by a relay of the trunk circuit which operates over a.

circuit independent of the talking circuit.

For a more complete understanding of this invention, reference should be had to the following description considered in connection with the accompanying drawing illustrating one embodiment thereof.

As shown in the drawing a trunk circuit A extends from one switchboard, preferably a central office V, to another switchboard Y Serial No. 259,426.

which may be of theprivate branch exchange type. At the central otfice switchboard there is provided a link circuit B which may be employed in initiating a call over the trunk circuit A or in answering a call incoming thereover. At the private branch exchange switchboard Y there is provided an extension circuit C, which is preferably employed in holding the trunk circuit while the operator thereat is locating a party for whom acall incoming over the trunk circuit from the central oflice has been received or when expectinga call over the trunk circuit. The apparatus shown to the left of the dotted line 2-2 is located at the central office switchboard and that shown to the right thereof is located at the private branch ex change switchboard. At the private branch exchange switchboard theremay be provided link circuits similar to link circuit B which may be employed to establish connections between the trunk circuit and telephone lines (not shown) which terminate at the private branch exchange switchboard. It will also vbe understood that telephone lines terminate at the central otlice switchboard, but since these form no part of the present invention they are .not shown.

The nature of the present invention is such that it is believed that it will be thoroughly understood from a description of the operation of the system shown in the drawing and it will be so described.

The operator at the switchboard X desiring to extend a call to the private branch exchange switchboard Y may insert plug 5 of cord circuit B into ack 6 of trunk circuit A, thereby lighting lamp 7 and operating cut-off relay 8. This operator may thereupon actuate ringing key 9, causing the energization of ring-up relay 10 over a circuit from the source or ringing current 11, lower alternate contact of ringing key 9, ring contacts of the plug 5 and the jack 6, resistance 1.2, condenser 13. contact 14 of slow-to-opcrate relay 15, left-hand winding of relay 10,

. tip contacts of ack 6 and plug 5 and the upper alternate contact of ringing key 9 to ground. Relay 10 upon being energized completes a locking circuit for itself from battery through contact 20 of relay and the contact and right-hand winding of relay 10 to ground. At the same time lamp 21 is lighted over a circuit from battery through contact of relay 15, contacts of relay 10,

contact 22 of relay 23 and lamp 21 to ground. The lighting of lamp 21 serves as a line signal to the P. B. X. operator. The energization of relay 10 also causes the operation of busy signals 16 and 17 associated with the trunk jacks at the P. B. X. These signals operate ,over a circuit from battery through contact 20 of relay 15, contacts of relay 10, contact 18 of relay 23, contact 41 of relay 15, windings of signals 17 and 16 and resistance 53 to ground.

The P. B. X. operator observing the lighted condition of the lamp 21 may insert the plug of a cord similar to cord circuit B into jack 24 of the trunk circuit. Belay 25 of the trunk circuit A thereupon operates, causing the energization of relay 26 over a circuit from battery through the winding of sloW-to-operate relay 15, left-handwinding of relay 26 and right-hand contact of relay 25'to ground. Relay 23 does not operate at this time due to the high impedance of the winding of the repeating coil and the left-hand winding of relay 23. Before the winding of relay 23 becomes sufli'ciently saturated to cause the relay to operate its circuit is interrupted by the relay 15, the o eration of which will be later described.

pon the operation of relay 25 supervisory relay 27 of cord circuit B and relay 28 of the trunk circuit are energized over a circuit from battery through the winding of supervisory relay 27, lower normal contact of ringing key 9, ring contacts of the plug 5 and the jack 6, contact 29 of relay 23, left hand contact of relay 25, contact 35 of relay 15, winding of relay 28, tip contacts of the jack 6 and the plug 5 and upper normal contact of the ringing key 9 to ground. Upon the energization of supervisory relay 27 a shunt circuit including resistance 36 is established about the supervisory lamp 7, causing the extinguishment thereof. The energization of relay 28 causes the closure of its contact, which establishes a short circuit about the left-hand winding of the relay 26. The lamp of the cord circuit connected with the jack 24 does not light until. the low resistance right-hand winding of relay 26 is included in parallel with the high resistance left-hand winding of relay 25, thereby reducing the resistance of the lamp circuit. Slow-to-operate relay 15 operates in series with relay 26 upon the closure of the right-hand contact of relay 25. This relay 15 is made slow to operate, so that impedance coil 39 will not be included in series with relays 27 and 28 until after these two relays have operated; Relay 15 in operating, opens contact 20, releasing relay 10 and extinguishing the lamp 21, closes contact 40 and opens contact 41, maintaining v the busy signals 16 and 17 operated, opens contact 35, removing the short circuit from the impedance coil 39 which it thereby-in sistance 12, and a portion of the ring talking strand of the trunk circuit A back to the contact 29 of relay 23. The P. B. X.

operator ma actuate the listening key of the connectec cord circuit immediately after plugging in, and the central oilice operator may actuate listening key 19 when the supervisory lamp 7 is extinguished. The operators may now converse, the central oflice operator advising the P. B. X. operator of the number of the line called or the name of the party wanted.

It the call is for a party whom the P. B. X. operator must locate, the cord circuit will be disconnected from the trunk circuit,

causing the release of the various operated relays, and plug-37 of the holding cord or extension circuit C inserted into the jack 24 for the purpose of holding the trunk circuit until the party is located. The holding key 38 of this holding cord circuit may be actuated before or after the insertion of the plug 37 into the jack 24. If this key is not actuated when plugging in, relay 23 will operate over a circuit from battery through contact 20 of relay 15, left-hand winding of relay, tip contacts of the jack 24 and the plug 37 and the upper normal contacts of listening key 49 and holding key 38 to ground. No other apparatus will function until the holding key is actuated, and when this key is actuated relay 23 will release. If this key 38 is actuated before the connection of the cord circuit with the trunk circuit, relay 23 will not operate upon plugging in, but immediately upon insertion of the plug in the jack, relay 25 of the trunk circuit will be operated over a circuit from battery through high resistance 30 the lower alternate contact of the holding key 38, sleeve contacts of the plug 37 and. the jack 24 and both windings of relay 25 to ground. Relays 26, 28 27 and 15 will now operate in sequence and in the manner previously described in connection with the functioning of these relays when the other cord circuit was connected with the trunk circuit. W hile reeaaae energized when included in series with the high resistance coil 30 and when its left-- hand winding is short-circuited. Upon the insertion of the plug 37 in the jack 24 and when the holding key 38 is actuated, slow-tooperate relay 45 is energized and in turn causes the energization of the slow-to-operate relay 46. The operation of relay 46 includes low resistance coil 47 and lamp 48 in parallel with the high resistance coil 30. These relays 45 and 46 are purposely made slow in operating in order that the lamp 48 may not be included in parallel relation with the high resistance coil 30 until after the operation of relay 28 and the release of relay 26. Otherwise relay 26 would remain energized and cause the lighting of the lamp 48 which is undesirable at this time. WVith the holding cord connected with the trunk circuit and the holding key actuated, supervisory lamp 7 of the cord circuit B, lamp 21 of the trunk circuit A and lamp 48 of the holding cord circuit C are extinguished.

If the central ofiice operator should desire to signal the P. B. X. operator, while the cord circuits B and C are connected with the trunk circuit A and the holding key 38 is actuated this may be done by withdrawing the plug 5 from the jack 6 and reinserting it therein or merely by momentarily actuating the ringing key 9. The withdrawal of the plug or the actuation of the ringing key causes the release of relay 28. thereby removing the short circuit ofthe left-hand winding of relay 26 which is now included in series with the winding of relay 15. Relay 26 is thereupon energized, closing its contact, thereby connecting the low resistance right-hand winding of relay 26 in parallel with the high resistance left-hand winding of relay 25. The resistance of the sleeve circuit is thereby reduced to such an extent that the lamp 48 of the holding cord circuit C is lighted over a circuit from battery through low resistance coil 47, left-hand alternate contact of relay 46, lamp 48, right hand alternate contact of relay 46, lower alternate contact of holding key 38, sleeve contacts of the plug 37 and jack 24. righthand winding of relay 25, and the left-hand winding of relay 25 and the right-hand winding of relay26 in parallel to ground. The lighting of this lamp 48 serves as a signal to the P. B. X. operator. The reinsertion of the plug 5 into the jack 6 or the restoration of the ringing key 9 to normal position causes the: energization of supervisory relav 27 and relay 28. The reestablishment of the short circuit of the lefthand winding of the relay 26 by the closure of the contact of relay 28 does not cause the release of this relay 26 for the reason that the low resistance coil 47 and the lamp 48 are now in parallel relation with the high resistance coil. 30. whereby the righthand winding of relay 26 receives sufiicient current to maintain this relay energized.

The P. B. X. operator may respond to the signal manifested by the lighting of the lamp 48 by restoring the holding key 38 to normal position and actuating the listening key 49 to connect the operators telephone set with the trunk circuit. The restoration of the holding key 38 to normal position causes the release of relays 45 and 46, thereby extinguishing the lamp 48. The restoration of this key 38 to normal position also causes the release of relay 26 and the momentary release of relays 25, 28 and 27, but these are immediately reenergized upon the actuation of the listening key 49 through the closure of the middle alternate contact thereof.

Should the P. B. X. operator desire to hold the trunk circuit A so that an outgoing call thereover may be made at some later time, but not to tie up the trunk circuit so that incoming calls may not be received thereover, the plug 37 may be inserted into the jack 24 with the holding and listening keys 38 and 49 in normal. position. Upon the insertion of the plug 37 into the jack 24 relay 23 of the trunk circuit operates over the hereinbefore-traced circuit. The operation of relay 23 causes the operation of the busy signals 16 and 17 over a circuit from battery through contact 52 of relay 23, contact 41 of relay 15, the windings of busy signals 17 and 16 and resistance 53 to ground. If the central office operator should now insert the plug 5 into the jack 6 and actuate the ringing key 9, relay 10 would be energized and locked up in the manner hereinbefore described, but the lamp 21 would not be lighted. The lamp 48 of the holding cord circuit, however, would be lighted over a circuit from battery through contact 20 of relay 15, contacts of relay 10. contact 50 of relay 23, resistance 51, ring contacts of the jack 24 and the plug 37, lower normal contact of listening key 49, left-hand normal contact of relay 46, lamp 48 and the righthand normal. contact of relay 46 to ground. The lamp 48 now serves as a line signal to the P. B. operator. Observing the lighted condition.v of the lamp 48, the P. B. X. operator may actuate listening key 49 to connect the telephone set with the trunk circunt. The actuation of this key 49 causes. the release of relay 23 and the operationv of relays: 25.26. 28. 27 and 15 followed by the release of relays 26 and 10. The energizing circuit for relay 25 now includes the middle alternate contact of the listening key 49 instead of the lower contact of the holding key 38. The lamp 48 is also extinguished.

If. while both the central office cord circuit B and the P. B. X. cord circuit C are connected with the trunk circuit A, the P. R. X. operator desires to signal the.

tral ofliceoperator, this may be done by in-- termittently actuating key 55. lfhe intermittent actuation of this key causes the intermittent energization of relay-23 which intermittently opens and closes the bridge across the talking conductors of the trunk circuit. Supervisory relay 27 is deenergized upon each opening of the bridge whereby the supervisory lamp 7 is intermittently lighted during the intermittent actuation of the key 55.

What is claimed is:

1. A telephone exchange system comprising a trunk circuit, a relay connected with the trunk circuit, a signaling device therein, a relay cooperating with the trunk relay to control the operation of the trunk circuit signaling device, a link circuit, and a direct current signaling device therein operated over a circuit including a contact of the second relay when the link circuit is subsequently connected with thetrunk circuit.

2. A telephone exchange system comprising a trunk circuit, a relay connected there with, a signaling device in the trunk circuit, a secondrelay, an operating circuit for the signaling device completed through a contact of the second relay upon the energization of the first relay, a link circuit subsequently connected with the trunk circuit causing the operation of the second relay, and a direct current signaling device in the link circuit operating over a circuit controlled by the energized relays.

3. A telephone exchange system comprising a trunk circuit, a relay responsive to ringing current connected therewith, a signaling device in the trunk circuit, an operating circuit for said signaling device completed through a contact of said relay, a link circuit, a signaling device therein, and a normally deenergized relay cooperating with the first relay when the first relay is energized to cause the operation of the trunk circuit signaling device and when energized by the connection of the link circuit with the trunk circuit cooperating with the energized first relay to cause the operation of the link circuit signalingdevice.

4. A telephone exchange system comprising a trunk circuit, a relay therein responsive to ringing current, another relay in the trunk circuit responslve to dlrect current, a link circult connected with the trunk circuit, a two-position switching device in the link circuit and a signaling device in the link circuit controlled by the first mentioned relay when the switching device is in one position and by the second mentioned relay when the switching device is in its other position.

5. A telephone exchange system comprising a trunk circuit, a relay in the trunk cir cuit responsive to ringing current, anotherrelay in the trunk circuit responsive to direct current, a link circuit connected with the trunk circuit, a two-position switching device in the link circuit, a signaling device in the link circuit, a third relay in the trunk circuit cooperating with the ringing response relay when the switching device is in one position for controlling-the signaling device, and a fourth relay in the trunk circuit cooperating with-the direct current response relay whenthe switching device is in its other position to control the signal: ing device.

6. In a telephone exchange system, in combination, a trunk circuit comprising talking conductors, a ringing response relay normally connected with the talking conductors, a direct current response relay normally disconnected from the talking conductors, a link circuit connected with the trunk circuit, a two-position switching device in the link circuit, a signaling device in the link circuit controlled by the ringing response relay when the switching device is in one position, and means in the trunk circuit effective when the switching device is moved into its other position to'disconnect the ringing response relay from the talking conductors and to connect the direct current response relay thereto whereby the direct current response relay cooperates with said means for controlling said signaling device.

7 In a telephone exchange system, in combination, a trunk circuit comprising a pair of talking conductors, a relay for the trunk circuit connected with the talking conductors and responsive to ringing current, another relay in the trunk circuit normally disconnected from the talking conductors'and responsive to direct current, a link circuit, a two-position switching device in the link circuit, a third relay in the trunk circuit energized upon the connection of the link circuit with the trunk circuit when the switching device is in one position, a signaling device in the link circuit, an operating circuit for the signaling device includinga portion of one of the talking conductors and contacts of the third relay when the ringing response relay is energized, a fourth relay in the trunk circuit energized when the switching device is moved into its other position and cooperating with the third relay to connect the direct current response relay with the talking conductors, and an operating circuit for the signaling device controlled by the fourth relay and including a contact of the switching device when in its said other position.

8. A telephone exchange system comprising an incoming circuit, an extension circuit connected therewith, a two-positioned neoted incoming and "extension circuits when the switching device is in one position to control the signaling device, and a second relay in the incoming circuit operating independentl of the first relay to control the signaling device when the switching device is in its other position.

9. In a telephone exchange system, a first exchange, a second exchange, a trunk circuit extending between said exchanges, means at said first exchange for signaling over said trunk circuit, asignaling device associated with said trunk circuit at said second exchange, a relay at said second exchange responsive to said signaling means when a call is initiated over said trunk circuit to actuate said trunk circuit signaling device, an operators link circuit at said second exchange, a signaling device therefor, and a second relay at said second exchange controlled from said second exchange and cooperating with said first mentioned relay when said link circuit is connected to said trunk circuit to actuate said signaling device of said operators link circuit.

10. In a telephone exchange system comprising an incoming circuit, a link circuit associated therewith, a signaling device associated with said incoming circuit, a signaling device associated with said link circuit, energizing circuits. for each of said devices, a relay in said incoming circuit, a second relay associated therewith, said relay serving to open the operating circuit of the signaling device in said incoming circuit and to close the operating circuit of the signaling device in said link circuit while said first relay is energized.

11. In a telephone exchange system, a first exchange, a source of current thereat, a trunk circuit, a source of current associated therewith, a second exchange and a source of current thereat, a signaling device in said second exchange, a relay in said trunk circuit at said second exchange, said relay being provided with a low resistance and a high resistance winding, a second relay associated with the first relay, said relay being responsive to current from the source of the trunk circuit and current from the source at said second exchange and servin when energized to short circuit the higli resistance winding of the first relay, and

means responsive to current from the source at said first exchange cooperating with said relays to control the signal device associated with said second exchange.

12. A telephone exchange system comprising an exchange, a source of current, a trunk circuit, a relay connected with said circuit, a signaling device in said trunk circuit, a link circuit, a source of current in said link circuit, a relay cooperating with the first relay to control said signaling device, a double wound relay in said trunk circuit, energized by the said source of current associated with said link circuit, a second double wound relay, a source of current in said trunk circuit for energizing one of the windings of said relay and thereby shunting one of the windings of said first mentioned double wound relay by the other winding of said second mentioned double wound relay to control the operation of the signaling device in said link circuit, and means responsive to current from the first mentioned source for also controlling the second double wound relay.

13. In a telephone exchange system, a first exchange having a source of current therein, a trunk circuit, a source of current and a signaling device in said trunk circuit, a second exchange, a signaling device, a source of current and a two position switching device in said second exchange, a relay in said trunk circuit energized by current from the source at the first exchange, a second relay in the trunk circuit energized by current from the source in the trunk circuit and cooperating with the first relay to control the signaling device in the trunk circuit and to control the signaling device in said second exchange when the switching device is in one position, a third relay energized by current from the source in the second exchange and a fourth relay responsive to current from the sources in said trunk circuit and in the second exchange and cooperating with the third relay to control the operation of the signaling device in the second exchange when the switching device is in its other position.

In Witness whereof, I hereunto subscribe my name this 18th day of October, A. D.

ROY D. CONWAY.

Images