US259285A - Telephone signaling-circuit - Google Patents

Description

7 (No Model.)

G. H. BLISS.

TELEPHONE SIGNALING CIRCUIT. No. 259,285. Patented June 13,131 882 H. PETERS, mwmwznw Wa-IMngin u. a

GEORGE H. BLISS, OF PITTSFIELD, MASSACHUSETTS.

TELEPHONE SIGNALING-CIRCUIT.

SPECIFICATION forming part of Letters Patent No. 259,285, dated June 13, 1882.

Application filed October 20, 1881.

To all whom it may concern:

Be it known that I, GEORGE H. BLIss, of Pittsfield, county of Berkshire, State of Massachusetts, have invented an Improvementin Telephone Signaling-Circuits, of which the following description, in connection with the accompanying drawings, is a specification.

My invention relates to the means employed for signaling in telephone-exchange systems, and has for its object to simplify the said means, and thus reduce both the first cost and cost of maintenance of the apparatus of the exchange.

The invention consists in the combination, with a series of subscribers circuits passing through a switch-board to the ground, each being provided with the usual indicating-instruments or annunciator-drops, of 'a battery having one pole connected with the ground and the other provided with a metallic conductor extended in branches to every subscribers station in the exchange, the said branches being normally open at each station, but adapted to be connected there with the subscribers line. By this arrangement, when one of the subscribers Wires is connected with the said battery-wire a current is passed through the indicating-instrument, giving a signal at the central office. The same battery may be employed for calling up the subscribers. In some instances, where certain groups of subscribers are remote from the main body of subscribers connected with an exchange,a local battery may be employed having one pole grounded and the other extended into all the stations of the said group.

Figure l is a diagram illustrating my invention, the battery-circuit bein g indicated by a heavier line than those employed to indicate the subscribers circuit. Fig. 2 is a similar diagram, showing the apparatus at the subscribers station and central office needed to put this invention in practice.

The subscribers circuits 1, 2, 3, &c., each passing through one or more subscribers stations, a, are connected with the usual switchboard, I), at the central office, each passing through an indicating-instrument, 0, (shown in Fig. 2,) to the ground. The said subscribers circuits are also grounded at the terminals remote from the central office in the usual manner, to enable signals to be sent from the cen- (No model.)

tral office. A signaling-battery, B, at the central oflice has one pole connected with the ground or common terminal of the subscribers circuits, and the other pole connected with the wire d, which is ramified so as to have a branch passing to each of the subscribers stations to, where it is normally open. At each subscribers station a suitable switch or key is employed, which may be of the form illustrated in Fig. 2, the subscribers wire 2, entering the station from the central ofice, being connected with a spring switch or key, 6, which normally remains in contact with a stop, f, from which the circuit is continued to the other stations on that circuit and ultimately grounded for the purpose of enabling signals to be sent from the central office. The battery-wire d is connected at each office with an anvil'piece, g, for the key 6, so that when the said -key is depressed that portion of the subscribers wire 2 between it and the central office is connected with the battery-wire and the circuit completed through the indicating-instrument c and battery B, as will be understood on referring to Fig. 2, while at the same time that portion of the subscribers line and the ground on the side away from the central office is disconnected from the said central office.

The battery B may also be connected by a wire, it, with a strip of the switch-board b, that can be connected by the central-office operator with any one of the subscribers circuits, and the current controlled by the key t'to operate a signal on the said connected subscribers circuit in any usual manner.

Where a group of subscribers circuits are remote from the main body of those forming an exchange, as shown at A, Fig. 1, the said subscriber being upon the circuits 10 12, leading to the switch-board b, a local signalingbattery, 13, may be employed, having one pole grounded and the other extended into all the subscribers stations of the said group. In this case, if one of the subscribers circuits,10 or 12, is connected at any station with the branch from the battery B and the ground at the end of the said circuit removed, the circuit of the battery B will be completed from the ground over the said subscribers wires 10 or 12, and through the indicating-instruments c therein at the central office to the ground, and thus operating the said indicating-instrument. In

this case the battery B will be employed for operating a signal from the central office to the stations on the subscribers circuits 10 12.

I do not broadly claim a battery at the central office having one pole connected with the subscribers wires and adapted to have its circuit completed from the subscribers station through the centraloffice indicating-instrument;

1 claim 1. In an exchange system, a series of subscribers circuits all entering a common central oflice, and each passing through a signalinginstrument, and a battery having one pole normally connected through the said signaling-instruments with the said subscribers wires, combined with a battery wire leading in branches from the other pole of the said battery into all the stations on the said subscribers circuits, and a device at each station for connecting the said subscribers wire with the said branch entering the station, substantially as and for the purpose described.

2. In an exchange system, a group of subscribers stations rem ote from others connected with the same central office, upon circuits entering the said otfice and passing through indicating-instruments to the ground, in combination with a battery located in the said group, and having one pole grounded and the other extended by normally-open branches into all the said stations, and means to connect the said branches at any station with the subscribers wire, substantially as and for the purpose described.

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

GEORGE H. BLISS.

Witnesses:

JAMES HARDING, JOHN F. VAN DEUs'EN.

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