US1194723A - David g - Google Patents

Description

D. G. DEE.

FIRE- ALARM APPARATUS.

APPLICATION men JULY 25.1912.

1 1 Patented Aug. 15, 1916.

a n r entice,

DAVID DEE, OF ROCHESTER, NEW YORK, ASSIQNOR TO DENIO GENERAL ELECTRIC COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

FIRE-ALARM APPARATUS,

Application filed July 25, 1912.

To ultwhom it 1f; (43/ concern Be it known that I, I)A\ll) G. DEE, of Rochester, in the county of Monroe and State of New-York, have invented'certain new and useful Improx'ements in Fire- "Alarm Apparatus; and I do hereby declare the following to be a full,'clear, and exact description of the same, reference being had to the accompanying drawings, forming a part of this specification, and to the reference-numerals marked'thereon. Y

My present invention relates to fire alarm 'apparatus,particularly to systems to be used pointed out in the claims at the end of the specification.

In the drawings: Figure 1 is a' diagrammatic view illustrating a call mechanism showing one embodiment of my present invention, and Fig. 2 is a detail view showing a modification thereof.

The apparatus embodying my present in vention is adapted to use in municipalities provided with telephone exchange systems, the fire alarm signaling or calling instruments used in conjunctiontherewith being adapted when set into operation, to transmit to the exchange operator, in addition to the impulses of current indicating the code signal of the instrument, other impulses which vibrate the diaphragm of the operators telephone receiver, to audibly indicate that an alarm has been turned in. The distinguishing signal is such that it may be immedi ately recognized by the exchange operator and not misunderstood, as a possible line disturbance, such as an intermittent ground applied to the circuit, or other line trouble. The provision of means whereby the central.

office operator may be quickly informed of the character of the signal possesses the advantage that it is unnecessary to wait until the sign-allng apparatus has been 1n operation for a length of time sufficient to permit a full Specification of Letters Patent.

Patented Au -.15; 1916.

Serial No. 711,471.

Y signal or round of the box to be turned .in, which would otherwise be necessary to distinguish such signal from some other effect which might be produced on the telephone line from outside causes. The idea of quickly informing the telephone operator at the central exchange of the character of the call which is being received is important in that the calling circuit may be more quickly connected to the fire department headquarters and a direct connection established between the subscribers alarm or calling apparatus and the alarmsounding and recording devices of the fire department.

The present invention isapplicable to any form or type of signal box which may be employed for transmitting a series of current impulses, orsuch impulses arranged in groups, the transmission of which will inclicate an alarm for some particular purpose despatched over the telephone subscribers instrument circuit.

In illustrating my present invention, I have shown a telephone subscribers instrument circuit, comprising the line wires AB leading from the tip and sleeve contacts of the switch-board jack J; said subscribers circuit comprising the transmitter T and the receiver R, suspended on the usual receiver hook 1 1 The alarm mechanism indicated by M may be located at any convenient point and will preferably comprise a clock train signal mechanlsm having the frame m and A from the contact spring 29.

The central oiiice apparatus, or switchboard mechanism', may be of the usual or any preferred construction and in the illust'rations I have shown diagrammatically the answering and calling cord circuits indicated by-lv and 2 respectively, receiving current from the battery 3, in circuit with which is the operators set comprising the receiver 4 and the transmitter Associated with the to thefire' department headquarters, com-.

prising a plug S from the tip and sleeve contacts of which extend the line wires s-s. This private circuit is fedwith current from a battery or other source of current 8 for actuating an electro-magnet a controlling an armature s which is adapted to be moved into engagement with the contact 8 said armature and contact being in a local circuit at the fire alarm headquarters comprising the wires .9 ends connecting the battery s and the electro-magnets s", by means of which the punch or marker 8 is operated to record the fire alarm signal on a tape 8.

The object of my invention is to provide" in conjunction with the circuit and alarm indicating mechanism described, means arranged in the alarm circuit whereby a distinctive signal is simultaneously transmitted over the line circuit with the transmission of the impulses of the alarm code. In the ordinary operation of the alarm mechanism the pilot lamp j will flicker or flash, in response to the impulses of current transmitted over the line circuit by the signaling mechanism. These flashes occurring at regular predetermined intervals and indicating the number of the fire alarm box in operation, cannot be distinguished by the central operator, as the pilot light may be similarly operated from other disturbances .on the telephone line, as for instance, by

the opening and closing of the receiver hook contact of a telephone set; an intermittent ground applied to the line; or an occasional short circuit thereon. For these reasons it isimpossible for the central oiiice operator to determine' immediately between such causes of'trouble and the regular operation of the fire alarm box. This necessarily causes delay in transmitting the signal to the fire headquarters, because if the operator is to make sure that the signal received is a proper fire alarm signal, it is necessary to wait until, at least, one complete round of the signal box has been transmitted. This also retards the traiiic on the switchboard, as the operator during this time, is prevented from responding to other calls.

The distinctive signal which I propose to use. is an audible one received by the central oflice operator in the receiver 4, produced by superimposing an induced current of frequent alternations on the circuit, when it is closed through the signal box. One means of carrying out the invention consists in extending from theside B of the circuit .a branch B whichleads to the normally open contact spring 9. The subscribers instrument set is cut out when the numeral wheel a is rotating at the contacts 0 and 0. Provided in the branch B of the circuit is an electro-magnet, having the windings Y) and the pole pieces in proximity to the'f'rec endsof which is arranged an armature G. Relative movement between the armature and the pole pieces is effected by mounting one of these parts, as for instance, the armature, in such a manner that it maybe vibrated or agitated mechanically during theoperation of the alarm mechanism to vary the air gap between said armature and the pole pieces of the magnet, which causes a change in the magnetic flux' flowing therethrough and generates or induces in the winding of the magnet an alternating" current thus superlmposing on the line a current whlch produces a distinctive signal- It is preferable.

that the vibration of the armature C should be 'apid, and to this end it may be conveniently supported, as shown in Fig. 1, and agitated by a hammer or clapper m operated by the detent m which controls the speed of operation of the clock train.

In Fig. 2 I have shown a modified arrangement of the parts in which the wire 13, corresponding to the wire B, is provided with the winding Z2 of an electromagnet, having the core pieces I), which are rigidly supported on the casing M of the signal apparatus. In this form of the device the armature (3 is shown supported upon the extremity of a spiral spring C, the inner end of which is attached to a rigid post C extending outwardly from the rear wall of the case M, in such position that the spring may be struck by the vibrating hammer m This form of'apparatus may be employed where it is desiredto sound a warning signal in the alarm box for the benefit of persons who maybe in that vicinity as well as to provide the distinctive signal for the central office operator. i

In operation, the alarm mechanism,'having-been actuated or set into action in the usual well known manner, becomes bridged across the subscribers line circuit and each time said circuit is closed through the projections on the wheel 11. and wiper g the pilot light J attracts the central office operators attention. The latter then places the answering plug 1 in the jack J and during the periods the circuit is closed the operator distinguishes the peculiarity of the audible signal,whereupon the answering plug 1 is removed and the special plug S of the fire alarm circuit is inserted in the jack J. The intermittent impulses of current then flowing over the circuit s-s energizes the magline circuits leading therefrom and supplied .net 8 causing a corresponding operation of the armature s and the recording device wires 8, s 7 I claim as my invention:

1. The combination with a telephone system provided with an operators receiver and subscribers line circu ts leading from the exchange, and subscribers line signal, and a central battery current, of a fire alarm apparatus comprising a normally-open alarm circuit in COI1]L1IlCt1OI1 with the subscribers line circuit, an alarm mechanism adapted to close and open sai'dalarm circuit, means operatedthereby to operate the line signal, and means operated by the alarm mechanism for superimposing an alternating current on I said circuit when closed in addition to the battery current to produce an audible signal in the central operators rece ver.

2. The combination with a telephone system comprising an exchange and subscribers with battery when closed, each subscribers line circuit being provided with a line sig- .nal, of a fire alarm apparatus comprising a normally open alarm circuit in conjunction with the subscribers line circuit, an electromagnet in said alarm circuit, an alarm mechanlsm adapted to cause current m-said circult to flow by impulses for operating the line signal aforesaid, and means for varying the magnet flux in the core of said magnet,

during the transmission of such impulses, said flux variations producing an induced current in the winding of the magnet which is impressed upon the line circuit when the alarm circuit is closed- 3. The combination with a centralenergy telephone system comprising subscribers line circuits which are normally open and are supplied with battery current from a central source when closed, each subscribers line circuit being provided with a central ofiice line signal, of a fire alarm mechanism adapted to cause said current to flow by impulses over a subscribers line circuit and thereby operate. the line slgnal thereof, and means actuated by said mechanism for imposing an alternat- 111g current on said circuit during the transmission of the impulses,

i. A fire alarm system for telephone lines comprising a normally open circuit leading from the said line and adapted when closed to close the line circuit and to beiener-gized by the current supplied to said line from the usual source, of. an electro-magnet arranged with its coil in said circuit and means 00- operating with the pole pieces of said mag-' net for varying the magnetic flux flowing through the core of the magnet and means for closing and opening the alarm circuit.

5. A fire alarm system for telephone lines comprising a normally open circuit leading from the said line and adapted When closed I to close the line circuit and to be energized polepieceslocated adjacent and arranged with its coils in said circuit, of an armature cooperating with said pole pieces, 'means for effecting a relative movement between the pole pieces and armature to vary the air gap between them and means for closing and opening said alarm circuit.

6. Thecombination with a subscribers telephone circuit-and a central oilice equipment comprising an operators receiver and an alarm mechanism associated with the circu'it for transmitting current impulses thcreon by opening and closing said circuit, of a magnet. winding interposed in the circuit, and an armature therefore, arranged to be yibrated by the operation of the alarm mechanism to induce an alternating current in the magnet which is superposed on the circuit to produce a distinctive audible signal in the operators receiver.

7. The combination with a telephone system comprisingan exchange having an op-- erators receiver and subscribers line circuits and provided with current from a cen tral source, of a fire alarm apparatus comprising a normally open alarm circuit, an alarm mechanism adapted to open and close saidalarm circuit and subscribers line circuit for transmitting an alarm signal over said alarm and subscribers line circuits, means controlled thereby to operate a line signal, and means operating upon the subscribers line andalarm circuits forgenerating and superimposing an alternating current upon said circuits when said alarmcircuit is closed', in addition to the alarm signal impulses, to produce an audible and distinctive signal in'the operators receiver.

8. The combination with a telephone system comprising an operators receiver and subscribers line circuitsand provided with battery current from a central source, of an alarm apparatus.associated with the subscribers line circuit comprising a normally open alarm circuit and an alarm mechanism adapted to open andclose both the alarm circuit and the subscribers line circuit, thereby transmitting alarm signal im pulses over said circuits from the central source of battery current, means controlled thereby to operate the line signal, and means operable by the alarm mechanism for superimposing an alternating current on said alarm circuit and said subscribers line cirimpulses aforesaid to produce an audible distinctive signal in the operators receiver.

9. The combination with the telephone system comprising an exchange provided with an operators receiver and subscribers line circuits and a line signal, of an alarm apparatus comprising a normally open ciriae cuit associated with the subscribers line circuit, an alarm mechanism adapted to open and close said alarm circuit and said subscribers line circuit, thereby sending alarm signal impulses over said circuit which 0p erate the line signal, and means associated with the alarm circuit for superimposing an alternating current on said alarm circuit and said subscribers line circuit upon the closing G. WILLARD RICH, RUSSELL B. GRIFFITH.

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