US1309248A

US1309248A - Automatic telephone system

Info

Publication number: US1309248A
Authority: US
Publication date: 1919-07-08
Anticipated expiration: 1936-07-08

Description

C. L. GOODRUM.

Patented J ully 8, 1919.

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AUTOMATIC TELEPHONE SYSTEM.

APPLICATION F'ILED JULY 28.1911.

Patented July 8, 1919. I

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CHARLES L. GOODRUM, OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

AUTOMATIC TELEPHONE SYSTEM.

Application filed July 28, 1917.

To all whom it may concern Be it known that I, CHARLES L. GOODRUM, a citizen of the United States, residing at New York, in the county of New York and lState of New York, 'have invented certain 'count of their knowing that it is impossible for the called party to nd out who is calling. It is, therefore, the object of this invention to provide means whereby a called subscriber can lock up the series of switches used to complete the connection from a calling line to his line, and also to cause an alarm to operate at the central oice to notify an attendant thereat t0l trace the connection and determine the line lupon which the call originated. p

In accordance ,with this object, a diii'erenti-al relay is provided in the battery supply circuit of the connector switches, and a push button is provided at each subscribers substation. When this ibutton is pressed at a called substation, one winding of the differential relay of the connector switch connected thereto, is shunted, thereby causing the relay to become energized and attract its armature which is mechanically locked up. The attraction of the armature permanently opens 'the release circuit of switches used in completing 'the connection, and thereby prevents the release of these `switches when either subscriber hangsV up 45-V hisreceiver. The attraction of the armature of the differential relay also causes an alarm to operate at the central office. This alarm notifies an attendant at the central office that a called lparty has locked up a series of switches and that he must trace out the connection and determine the line upon which the call originated.

It is believed that the invention will best be understood by tracing a call from a call- Specication of Letters Patent.

Patented July s, 1919.

Serial No. 183,295.

ing subscribe-r to a called subscriber, reference being had to the accompanying drawings, in which Figure 1 diagrammatically shows a calling substation, a line finder switch and a first selector switch; and Fig. 2 diagrammatically shows a connector switch and a called substation.

When the subscriber at substation A removes his receiver from the hook, a circuit is completed from grounded battery, left-hand winding of relay 1, outer armature and back contact of relay '2, telephone apparatus at substation A, sender S, back contact and inner armature of relay 2, right-hand winding of relay 1 to ground. Relay 1, 'by attracting its armature, completes a circuit from grounded battery, left-hand winding of relay 1, outer armature and back contact of relay 2, conductor 3, armature andv front Contact of relay 1, contact spring 70, back contact and left-hand armature of relay 4, winding of relay 5 to ground. Relay 5, by attracting its left-hand armature, completes a locking circuit for itself which is independent of the armature and back contact of relay 4. Relay 5, by attracting its right-hand armature, completes a circuit from grounded battery, winding of relay 6, right-hand armature and front contact of relay 5 to ground. Relay 6 at its right-hand armature and front contact, completes a circuit from grounded battery, winding of relay 4, right-hand armature and front Contact of relay 6 to ground. Relay 4 `becomes energized and by attracting its right-hand armature maintains the release circuit of the line finder open during the operation of the line finden Relay 6 at its left-hand armature and front contact, completes a circuit from grounded battery, winding of primary magnet 7, sideswitch arm 8, back contact and armatureof secondary magnet 9, armature and back contact of primary magnet 7, right-hand armature and back4 contact of release magnet 11,

` ing subscribers line. When the arm 14 engages tliis contact 15,`gr0und will be found thereon, which Completes the following cir1 v cuit-from grounded battery, winding of primaintained energized by the current flowing through this circult, thereby preventing further stepping of the switch. The escape magnet 10 is also energized by the current flowing through this circuit and upon its energization moves the side-switch arms into their Isecond position.

In position 2primary magnet 7 and the escape magnet 10 are maintained energized over the following circuit, from `grounded battery, winding of primary magnet 7 Winding of escape magnet 10, side-switch arm 13, vside-switch arm 12. left-hand armature and front contact of relay6, right-hand armature andfront contact of relay 5 to ground. 3A stepping circuit is now closed for the secondary magnet 9 from grounded battery, winding of secondary magnet 9, side-switch arm 8, back contact and armature of secondary magnet 9,.righthand armature and front contact of escape magnet 10, right-hand armature and back contact of release magnet 11, side-switch arm 12, lefthand armature and front contact of relay 6, right-hand armature and front contact of relay 5 to round. This steppingcircuit for the secondary magnet 9 is maintained until the brushes 16, 17'and 18 of the line finder engage the

terminals

19, 20 and 21; of the calling line, at which timev a circuit 1 s completed from grounded battery, winding of the cut-olf relay 2, terminal 19, brush 1.6, contact sprin 23, left-hand armature and front contact o escape magnet 10, resistance 22, side-switch arm 12, left-hand varmature and front contact of relay 6, right-hand armature and front contact of relay 5 -to ground. ,Rela hoylding circuit of relay 5,. Relay 5 becomes denergized and opens the circuit of escapey magnet 10, which denerg'izes and moves the side-switch arms into their third jposition'. Relay 2 is still maintained energized in position 3y over a circuitffrom grounded battery, winding of relay 2, lterminal 19, brush 16, contact spring 23, make-before-break contact 7 left-hand armature and back' contact of releasev magnet 11- to ground. As soon as the side-switch arms 24 and 25 move into their third position, the circuit is completed for line relay 26 of the first selector switch from grounded battery, left-hand winding of relay 26, side-switch arms 27 and 25, brush 17 terminal 20, telephone apparatus at substation A, sender S, terminal 21, brush 18, side-switch arms 24 and 23, righthand winding of relay 26 to ground. Line relay 26 by attracting its armature, completes a circuit from grounded battery, winding of relay 29, front contact'and armal2 by attracting its armatures, opens they series of impulses. In response to each impulse transmitted,l the line relay 26 is mo- @mentar'ily denergized, thereby closing the circuit from grounded battery, Winding ofl prlmary magnet 31, secondary ofi-normal contact 32, front contact and'armature of relay 29, back contact and armature of relay 26 yto ground. A circuit is also completed in parallel with primary magnet 31 from l grounded battery, winding of relay 30, front contact and armature of relay 29, armature and back contact of relay 26 to ground. The energization of relay' 30 completes the circuit 'rom grounded battery, winding of escape magnet 33, side-switch arm 36, armature and front contact of relay 30 to ground. Relays 29 and 30 are arranged to maintain their armatures attracted during the transmission of the impulses. At the end ofthe first series of impulses the line relay -26 remains energized for a suficient length of time to cause the denergization of relay 30,

which in turn causes the denergization of escape magnet 33` t0 move the side-switch arms into their second position.

In -position 2 a stepping circuit isclosed for the secondary magnet 34 from grounded battery winding'of secondary magnet 34,

armature and back contactof this magnet, side-switch arm 35, front contact and armature of relay 26 to ground. Each energization of the secondary magnet 34 moves the brushes 38, 39 and 40 of the selector switch .into engagement with the terminals of a trunk in the selected group. As long as busy trunks are engaged by the brush 38, no

potential will be found upon the terminal 41,

but as soon as the terminals of an idle trunk.

are engaged, ground will be found upon the test terminal 41, thereby completing a circuit from grounded battery, winding of escape magnet 33, side-switch arm 36, brush 38, terminal 41 to ground at the idle connectorswitch. Escape magnet 33 becomes energized and moves the sideswitch arms into their third position.-

Side-switch arms 27 and 28by 'movingv into l'their third position extend the calling line through to the connector switch. A circuit is then completed from grounded battery, right-hand winding of line rel-ay '44,

terminal 42, brush 39, side-'switch yarms 27' and 25, brush 17 terminal 20, telephone apparatus at substation'A, sender S, terminal 2l, brush 18, side-.switch

arms

24 and 28,

brush 40, terminal 43, left-hand winding of line relay 44 to ground. The energization of relay 44 completes ai circuit from grounded battery, winding of relay 45, armature and front contact of relay 44. back contact and armature of diiierential relay 62 to ground. The apparatus .is now in condition for the second series of impulses.

In response to each impulse of this series the line relay 44 is momentarily denernet 47, side-switch arm 48, front contact andA right-hand armature of relay 45, back contact and armature of relay 44, back contact and armature of differential relay 62 to ground. A circuit is also completed for relay 46 in parallel with primary magnet 4.7. Relays 45 and 46 are arranged to maintain their armatures attracted during the transmission of the impulses. The energization of relay 46 completes a circuit from ground-y ed battery, front contact and right-hand armature of relay 46, winding of escape magnet 49, back contact and armature of relayl `to ground. At the end of the sec- ;"bnd series of impulses, line relay 44 is maintained energized, thereby causing the deenergization of relay 46. Relay 46-by retracting its right-hand armature opens the circuit of escape magnet 49 which denergizes and moves the side-switch arms into their second position.

In response to the third series of impulses the line relay 44 will be momentarily denergized in the same manner as above, causing the following circuit to be completed from grounded battery, winding of secondary magnet 50, side-switch arm 48, front contact and right-hand armature of relay 45, back Contact and armature of relay 44, back contact and armature of differential relay 62 to ground. A circuit is also completed for relay 46 in parallel with the secondary magnet 50. Relay 46 by attracting its righthand armature again completes vthe energizing circuit of escape magnet 49 in the manner above described. At the end of the third series of impulses the line relay 44 is maintained energized, thereby causing the deenergization of relay 46. In response to the second series of impulses, brushes 55, 56 vand 57 are moved into operative relation with the terminals of the group of lines containing the called subscriber. In response to the third series of impulses the

brushes

55, 56 and 57 are moved into engagement with the terminals of the line extending to the called substation. We will first assume that the called line is busy and, therefore. ground will be found upon the test terminal 58. If this line is busy as a called line, this ground will be connected through side-switch arm 52 and brush 55 of the connector switch connected thereto, or if busy as a calling line, ground will be connected through the lefthand armature and back contact of release magnet. 11. malte-before-break contact 71, contact spring 23 and brush 16 of the line finder connected thereto. Therefore, when relay 46 denergizes after the third series of impulses. a circuit will be completed for release magnet 68. provided thc called line is busy, this circuit being traced from grounded battery, winding of release magnet 68, right-hand armature and back contact of relay 61, off-normal contact 67, lefthand armature and back Contact of relay 46, side-switch arm 52, brush l55, terminal 58 to ground. Release magnet completes a .locking circuit for itself from grounded battery, winding of release magnet 68, lefthand armature and front contact of this magnet, off-normal contact 81 to ground. Since the escape magnet 49 is made slow to retract its armatures, the circuit for the release magnet 68 will be closed before the side-switch armatures move into their third position. The energization of the release magnet 68 removes the holding pawls of the connector switch in the well known manner, thereby causing the switch to return to its normal position. The release magnet 68 at its right-hand armature and front con tact connects the busy tone apparatus 8O to the lower line conductor, thereby notifying the calling subscriber that the called line is busy. The release magnet 68 at its lefthandarmature and front contact completes the circuit of the release magnet 1'1 of the lme finder switch from grounded battery, winding of the release magnet 11, primary off-normal contact 74, right-hand armature and back Contact of relay 4, side-switch arm 87, brush 33, terminal 41, conductor 76, lefthand armature and front contact of relay 45, front contact and left-hand armature of release magnet 68, oii"normal contact, 81 to ground. A circuit is also completed in parallel with magnet l1 from grounded battery, winding of the 4release magnet 72 of the first selector switch and primary offnormal contact 73, The release magnets 11 and 72 become energized and return the line finder and the first selector respectively to their normal positions in the well-known manner.

,lf the called line had been idle at the time the brush 55 engaged the terminal 58, no ground would have been found thereon, so that the denergization of relay 46 would have caused the denergization of escape magnet 49 and the side-switch arms would have been moved into position 3.

In position 3 a. circuit is 'completed from grounded battery, Winding of relay 46, side- 'switch arm 48, front contact and armature of relay 44, back contact and armature of differential relay 62 to ground. Relay 46 becomes energized and again completes the energizing circuit of escape magnet 49. Escape magnet 49 by attracting its armature completes a circuit from ringing generator (not shown), front contact. and armature of escape magnet 49, winding of marginal relay 51, side-switch arm 53, brush 56, terminal 59, telephone apparatus at substation B, sender S. terminal 60, brush 57,"s1de-switch arm 54, front contact and armature of relay 44 to ground. The current flowing through this circuit is no-t suflicient to operate marginal relayfl at this time, but as soon as the subscriber at substation B removes his receiver from the hook, thereby shunting the -ringer at his substation, sufficient current Hows through the marginal-relay 51 to cause it tol,rattract its armature and open the circuit of the escape magnet 49. Theescape magnet 49 -denergizes and moves lthe sideswitch arms into their fourth position.

rIhe subscribers are now connected for conversation, current being supplied to the -called subscribers line from grounded battery, left-hand winding of relay 61, lefthand winding of dierential relay l62, sideswitch arm 53, brush 56 terminal 59, tele-` phone apparatus at substation B, sender SQ v.terminal 60, brush 57, side-switch arm 54,4

.tion of relay 44 causes in turn the ,denergization/ of relay 45. Ground is then conf nected to the release conductor 76 through p over this conductor.

armature and back contact Aof differential relay 62, amature and back contact of relay 44, right-hand armature and back contact of relay 45 and left-hand armature and back contact of relay 61. Circuits are then completed for release magnets 11, 72 and 68 It will be seen that after connecti-o-n is once established the release of the switches used in completing the connection is'controlled at the armature and back contact of the differential relay 62. If,

however, the called party wishes to find out who is talking to him, he presses the key K1 before the calling party hangs up. The pressing of this key connects ground directly to the left-hand winding of the differentia-l relay 62. This shunts the righthand winding of the relay and causes it to attract its armature. Thearmature is mechanically locked up in its attracted position by the catch 63. The engagement of the arma.- ture of relay 62 with the catch 63 completes a circuit from grounded battery, winding of the relay 65, lamp 64, catch 63, armature of relay 62 to ground. The current flowing through the circuit energizes the relay 65 and lights the lamp 64. Relay 65 by attracting its armature completes acircuit for the Ibuzzer 66 fro-m grounded battery, winding and armature and back contact of buzzer 66, armature and front contact of relay 65 to ground.` The attendant at the central office hearing this buzzer, is informed that a certain series of switches has been locked.

up, and seeing the light 64 which is indi-m vidual to a particular connector, knows that that particular connector and the switches connectedthereto are the ones that should be traced to find out upon what line the call originated. The attraction ofthe armature ofrelay 62 remo-ves ground from the release conductor 7 6 and thereby prevents the release of any of the switches when the called and calling parties hang up their receivers.

-What is claimed is: V

1. In -a telephonesystem, a calling subscribers line, a called su'bscribers line, autof matic switches, means for operating said switches to complete a connectionv between said subscribers lines, releasing means for said switches normally under'the control of said subscribers, and means under the control of the called subscriber for removing the control of said releasing means from both of said subscribers.

2. In a telephone system, a calling subscribers line, a called subscribers line, automatic switches, means for operating said switches to complete a connection between said subscribers/lines, a release magnet for each switch,Y circuits for` saidrelease magnets normally under the control of said subscribers, and means under the control of the called subscriber forpermanently opening said release circuitsto remove the control of said circuits from both'of said subscribers..

3. In a telephone system, a calling subscribers line, a called subscribers line, automatic switches including a connector switch, means for operating said switches to complete a connection between saidsubscribers lines, a differential relay at said connector switch,` a vrelease magnet for each of said switches, circuits for said release magnets controlled by said differential relay, and means under the control of the called subscriber for operating said relay to prevent theoperation of any of said release magnets by either of said subscribers.

controlled by said differential relay, and" means under the control of said called sub1 scriber for shunting one winding of said relay to cause ther operation thereof to prevent the operation of any of said release magnets by either of said subscribers.

5. AIna telephone system, a calling subscribers line, a called subscribers line, automatic switches including a connector switch, means for operating said switches tocomplete a connection between said subscribers lines, a differential relay at said connector switch, a release magnet for each of said switches, circuits forsaid release magnets controlled by said differential relay. a mamially operable device at the called subscribers substation, and means operated in response to the operation of said device by the called subscriber for shunting one winding of said relay to cause the operation thereof to prevent the release of any of said switches of either of said subscribers.

6. In a telephone system, a calling sub,- scribers line, a called subscribers line, a central office, automatic switches thereat.` means for operating said switches to complete a connectionbetween said'. subscribers lines, a releasing means for said switches normally under the control of said subscribers, an attendants position at said central office, a signal at said position, and means under the control of the -called subscriber for removing said releasing means from under the control of said-subscri'bers, and for operating said signal at said position to notify the attendant t0 ascertain the calling s-u'bscribers line, for the called subscriber.

7. In a. telephone system, a calling subscribers line, a called subseribers line, a central ofiice, automatic switches tliereat, means for operating said switches to complete a connection between said subscribers lilies, a release magnet for each switch, circuits for said release magnets normally under the cont'rol of said subscribers, an attendants position at said central office, a signal at said position, and means under the control of the called subscriber for permanently opening said release circuits to remove said release magnets from under the control of said subscribers, and for closing a circuit for said signal to notify the attendant to ascertain the calling subscribers line for the called subscriber.

8. .In a telephone system, a calling line, a

called line, a central office, automatic switches including a connector switch at said office, means for operating said switches to complete a connection between said lines, a differential relay at said connector switch, releasing means forsaid switches cont-rolled by said relay, an attendants position at said office, a signal at said position, and manually operable means at the called partys substation for causing said relay to operate to prevent the operation of said releasing means by either of said parties and to cause said signal to operate to notify the attendant to ascertain the calling line for the called Party;

9. In a telephone exchange system, a central oflice, a signal thereat, calling and called subscribers lines terminating at said central ofiice. automatic switches for interconnecting said lines, means under thel control of the called subscriber for locking said switches in an actuated condition to mainl1. In a telephone exchange system, calling and called subscribers lines, automatic switches for interconnecting said lines, meansfor releasing said automatic switches, and electromagnetic means under the exclusive control of the called subscriber for preventing the operation of said releasing means.

12. In a telephone exchange system, calling and called subscribers lines, automatic switches forv interconnecting said lines, means for releasing said automatic switches, and means operable at will by the called subscriber exclusively for preventing the operation of said releasing means.

13. In a telephone exchange system, subscribers lines, automatic switches for interconnecting said lines, means for releasing said automatic switches, a differential relay for controlling said releasing means, and means under the exclusive control ofthe called subscriber for causing said differential relay to prevent the operation of said releasing means.

7114.- In a telephone exchange system, subscribers lines, automatic switches for. inter .connecting said lines, means for releasing said automatic switches, a differential relay for controlling said releasing means, and means operable at will by the called subscriber exclusively for causing-the differential relay to Vprevent the operation of said releasing means.

15. In a telephone exchange system, subscribers lines, automatic switches for interconnecting said lines, a differential relay, a circuit for releasing said switches including the armature of said differential relay when both of its coils are energized, and means operable at will for shunting one winding of said differential relay and thereby breaking the circuit for releasing the automatic switches.

16.111 a telephone exchange system, subscribers lines, automatic switches for interconnecting said lines, a differential relay, a circuit for releasing said switches including the armature of said differential relay when both of its coils are energized, and means under control of the called subscriber for shunting one winding of said differential relay thereby breaking the circuit for releaslay, and means under the control of the called subscriber for operating said relay to preventthe operation of any of .said release magnets by either of said subscribers.

18. In a telephone system, a calling line, a called lline, a central oiice, automatic 'switches at said office, means for operating said switches to complete a connection between said l1nes, a dilerential relay, releasing means for said switches controlled bysaid relay, an attendants position at said oiice, a si al at said position, and manuallyv opera le means at the called partys substation for causing said relay to operate' to prevent the operation of 'said releasing I v means by either of said parties to cause said signal to notify` the attendant to ascertain the calling line for the called party.

191 In a telephone exchange'system, subscribers lines, automatic switches for interconnecting said lines, a differential relay, a'

circuit for releasing said switches including the armature ofsaid dii'erential-relaywhen both of its coils arev energized', and means operable by the called 'subscriber for 'shunting-one. winding of said differential relay and causing said relay to attract its armature and thereby breaking the circuit for re. I

leasing the automatic switches, and*- means for latching the armature ofsaid 'relay in its attracted osition. 20. In a te ephone exchange "system, "sub: scribers lines, automatic Iswitches'forinterconnecting said lines, a central oilice, a'sig-'f nal thereat, a differential relay, av circuit for the called subscriber .for shunting one winding' of said differential relay and thereby vreleasing said switches including the arma- `ture of said diiferential relay when vboth of. its coils are energized, means operable by*r causing said relay to attract its armature for breaking the circuit .for releasing the automatic switches, a latch for retaining the armature loi the differential relay in its attracted position, and a circuit established throughsaid armature and latch for ,operating saidy signal at the central ofiice.

In witness whereof I hereuntosubscribe my name this 21st day of July, A. D. 1917.

, CHARLES L. GOODRUM.