US782323A - Telephone system. - Google Patents

Description

PATENTED PEB. 14, 1905. D. W. CAMPBELL. ...K

TELEPHONE SYSTEM.

APPLIOATION FILED JUNE'ZI, 1904.

zy! fttorn ey .5.

No. 782,323. PATENTED PEB. 14, 1905.

D. W. CAMPBELL.

l TELEPHONE SYSTEM.

APPLIUATION FILED JUNE 21, 1904 2 SHEETS- SHEET a.

UNITED STATES Patented February 14, 1905.

PATENT OEEICE.

W. CAMPBELL, OF LA CROSSE, `VVISCON SIN, ASSIGNOR TO THE VOUGHT-BERGER COMPANY, A CORPORATION OF WISCONSIN.

TELEPHONE SYSTEM.

SPECIFICATION forming part of Letters Patent No. 782,323, dated February 14, 1905.

i Application filed J une 21,A 1904. Serial No. 213,446.4

To all whom, t may concern:

4 that class commonly known as multiple central-energy telephone apparatus.

One of the objects of this invention is to provide a telephone system having., circuits which allow transmission of speech over solid conductors without the interference of relaywindings or relay-contacts. Another object is to provide a telephonecircuit When both stations are plugged up which permits the speech-waves to have a clear passage over both connecting-plug cords without detrimental impedance or high resistance.

To these ends my invention consistsof'the features of construction and combination of parts hereinafter described and claimed.

In the accompanying drawings, Figure l is a diagrammatic view of my improved centralenergy telephone system, which illustrates a complete central station and a pair of telephone instruments connected therewith,- the parts being shown in normal position-viz.,

the receiver at the subscribers station hung up and the plug at central out of connection with the jack. Fig. 2 is a detail diagrammatic view showing the connection when the answering-plug is inserted in the jack at the central station and the receiver at the subscribers telephone instrument is down, and Fig. 3 is another detail diagrammatic view showing the connections when the receiver is hung up while the plug remains in said jack.

A and B represent two telephone instruments, C their respective lines, D their switchboard-jacks and switchboard apparatus, and E the voperators connecting-cord circuit for working the same.

The following description applies equally t0 both sides of the system, they being numbered in accordance with the specifications herein given.

The telephones A and B, of ordinary construction` have a switch-arm 3 connected with the side 4 of the instrument line-circuit C and the primary winding 14 of induction-coil I4a and condenser 3b connected with the other side. The primary coil is also connected with the transmitter 15, which in turn is connected with the upper contact-point 17 ofvthe'switch. The lower contact-point 3c is connected with the callbell 3, which in turn is connected with the condenser 3b. The receiver 2 is connected with the secondary winding 3d of the induction-coil.

The central switchboard apparatus consists as follows: A battery F, the current of which is fed to the apparatus at thelcentral exchange and tothe telephone instruments, has a pair of main feedwires 6 and 7 'leading therefrom. The wire 4 of the instrument-circuit` is connected with the impedance-coil 5, which in turn is connected with the wire 6. The wire 4 is also connected with the spring side 35 of the jack D. The wires 4 6, with their impedance-coil, constitute what I have chosen to term the impedance-coil side .of the instrument and battery circuit. The Wire 12 of the instrument-circuit is connected with the relay 10, which in turn is connected in series with the impedance-coil l8, leading from the wire 7 of the battery-circuit. The Wire 12 is also connected with the spring 23 or sleeve' sideof the jack D. The thimbles 24, which receive the sleeve side of the operators plugs,

`is connected with the wire 9 between the jacklay 10 is energized by removing the receiverl 2 from the switch-hook 3, the signal-lamp 20.

is illuminated.

The answering-plug G is of ordinaryconstruction and has its sleeve 27 connected by the wire 26 Awith the relay 25, which in turn is connected with the main wire 7, leading from the battery, by means of the wires 25 and 31. The tip 34 of the answering-plug G is connected, through, the wire 33, switch 42, contact-point 43, wire 32, relay 29, contactpoint 30, armature 28, wires 44 and 31, with the wire 7 of the main battery-circuit. The armature 37 is permanently connected by the wire 31 with the wire 7 of the battery-circuit and by the local circuit-wire 40, containing the lamp 39 and the contact-point 38, with the wire 6 of the battery-circuit when the relay 2,9 is energized and the armature drawn down. The plug-circuits have connected therewith a local telephone instrument H and amagneto-generator I in the ordinary manner.

When a subscriber takes down a receiver 2 from the switch-hook 3, a circuit is established as follows: hook 3, (at telephone instrument A,) wire 4, impedance-coil 5, Wire 6, and positive battery, from negative battery over wire 7, impedance-coil 8, wire 9, relaywinding 10, wires 11, 12, 13, primary winding 14 of induction-coil, transmitter 15, wire 16, contact-point 17, and back to hook 3. The establishment of this circuit energizes relay 10, causing it to pull up armature 18 and cornplete a circuit from battery through wire 7, armature 18, wire 19, lamp 20, and wire 6 back to positive battery. This gives the switchboard operator the signal, whereupon the answering-plug G is inserted in jack D. This action short-circuits wire 22, relay 10, wire 11, jack-spring 23, and jack-thimble 24. This denergizes relay 10, thereby releasing armature 18 and cutting out lamp 20. At the same time a clear talking-circuit is completed from negative battery, as shown in Fig. 2, through the relay 25, wire 26, plugsleeve 27, jack-sleeve spring 23, wires 12 and 13, induction-coil 14, transmitter 15, wire 16, hook-switch contact 17, hook-switch 3, wire 4, impedance-coil 5, and wire 6 back to positive battery. The l energizing of relay 25 causes its armature 28 to pull up, cutting out the relay 29. When the subscriberis through talking, he will then hang the receiver 2 on the hook 3, which opens the instrument-circuit. This cuts the battery oif of the sleeve side of the jack and causes the relay 25 to release its armature 28. This armature will then resty against the relay-contact 30, and the current iows, as shown in Fig. 3, from negative battery through wire 31, armature 28, contact-point 30, relay-winding 29wire 32, wire 33 to thetip 34 of the plug Gr, jackspring 35, wire 36, impedance-coil 5, and Wire 6 to positive battery. This causes the armature 37 ofthe relay-winding29 to swing down and make contact with the contact-point 38.

A The current then iows from negative battery through wire 31, armature 37, contact-point 38, disconnect-lamp 39, wires 40 and 6 to the positive battery and notifies the operator that the instrument is not in use. As soon as the plug G is pulled out of the jack all of the relay-armatu res fall into normal position and cut the lamp 39 out, as shown in Fig. 1.

Current is fed from the battery F to the telephone instrument when connected to the central apparatus through the impedance-coil 5 on one side of the line. On the other side of the line the current is fed through the relay 10, impedance-'coil 8, and relay 25 in multiple. The relay 10, impedance coil 8 in series, and relay 25 in multiple with these two have a combined resistance equal to that of impedance-coil 5 for the purpose of distrihuting the current equally without what is commonly known as impedance effect or high resistance when the talking-circuit is completed.

Having described my invention, what I claim as new, and desire to protect by Letters Patent, is-

1. A telephone-line, a telephone-switch at the station thereoi` Jfor changing the circuit of the line in the use of the telephone, a springjack for the line, a call-signal at the switchboard, a plug, a plug-circuit for making connection with said jack, a call-signal relay on the line-circuitat the switchboard, an impedance-coil in series with said relay, a disconnect-lamp circuit at the switchboard, a relay in theplug-circuit to open said disconnectlamp circuit when the telephone is in use, and a main impedance-coil in theline-circuit equal in resistance tol that of the combined resistance of the call-signal relay and the call-signal impedance-coil in series and the disconi is made with said jack and the telephoneout of use, and a main impedance-coil in the'linecircuit equal in resistance to that of the combined resistance of the call-signal relay and the call-signal impedance-coil in series and the disconnect-lamp relay in multiple with these two.

3. A telephone-line, a telephone-switch at the station thereof for changing the circuit of the line in the use of the telephone, a springjack for the line, a plug, a plug-circuit for IOO IIO

, the telephone, a jack for the line, a call-signal making connection with said jack, call and disconnect signaling means at the switchboard, a system of impedance and relay coils connected with said circuit for controlling the operation of said signaling means, and arnain impedance-coil connected with said line and equal in resistance to the combined resistance of said system oi' impedance and relay coils, for the purposes specified.

4. In combination with a telephoneline, a telephone-switch at the station thereof for changing the circuit of the line inthe use of at the switchboard, a plug-circuit for making connection with said jack, a call-signal relay 10 at the switchboard, an impedance-coil 8in series with said relay, a relay 25 in said plugcircuit, an auxiliary relay 29 also in said plugcircuit, a disconnect-lamp and circuit opened and closed by said auxiliary relay, said relay 25 adapted to control the operation of said auxiliary relay, and a main impedance-coil 5 in the line-circuit equal in resistance to the combined resistance of the relay 25and the resistance of the relay l() and impedance-coil 8 in series.

5. A telephone-line` a telephone-switch at the station thereof for changing the circuit of the line in the use of the telephone', a jack for the line, a call-signal at the switchboard, a plug, a plug-circuit for making connection with said jack, a disconnect-lamp, a disconnect-lamp circuit at the switchboard, a main impedance-coil in the line-circuit, and a system of relays and impedance-coils at the switchboard `connecteol with said circuits having a combined resistance equal to that of said main impedance-coil.

In testimony Whereofl have signed my name to this specification in the presence of two subscribing Witnesses.

DANIEL W. CAMPBELL.

Witnesses: i

A. M. PRIDEAnx, MILLS TOURTELLOTTE.

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