US819873A - Burglar-alarm. - Google Patents

Description

PATENTED MAY 8 W. N. FAWGETT.

BURGLAR ALARM.

APPLICATION FILED MAY19,1905.

UNITED STATES PATENT OFFICE.

WVILLIAM N. FAVVOETT, OF NE YORK, N. Y., ASSIGNOR OF ONE-THIRD TO MORRIS BERNHARD AND ONE-THIRD TO MARCUS BURCKHEIMER,

OF NEW YORK, N. Y.

BU RGLAR-ALARIVI.

Specification of Letters Patent.

ratented May 8, 1906.

To all whom it may concern:

Be it known that I, WILLIAM N. FAWCETT, a citizen of the United States, residing at the city of New York, in the borough of Brooklyn, county of Kings, State of New York, have invented certain new and useful Improvements in Burglar-Alarms, of which the following is a specification.

The object of my invention is to provide a new and improved burglar-alarm which is simple in construction, reliable and eiiective, and permits cutting out any closure without rendering the entire system inoperative and by means of which the break in the line can readily be discovered.

In the accompanying drawing my improved burglar-alarm is shown diagrammatically.

I have illustrated my burglar-alarm as applied on three doors A, A and A but it may as well be applied on more or less or on other closures or in walls, 620. I have also shown two sets of wiring, one in full lines and the other in broken lines, although only one set may be used, two, however, being pre ferred for reasons that will appear later on. A gravity-battery B is used for the closed circuits, and an ordinary battery C, such as a Le Clanche or dry cell, is provided for the open circuit.

The battery C is connected with an electric bell D, and its terminals are connected by the wires a and b with the two spring-contacts E, a switch F being interposed in the wire or conductor a. The electromagnet F is in the circuit of the closed-circuit line and is fixed on an inclined support G. Its pivoted armature H can thus drop away by gravity, and when this armature drops or swings down the weighted projecting arm J on the armature snaps in between the two spring-contacts E in the manner of a knife-switch, thus closing the circuit of the open-circuit line C D b E F 0. Thus when the switch F is closed and the circuit of the closed-circuit line is broken and the magnet F releases its armature the weighted arm J swings down and closes the circuit of the local or bell battery and the bell D is sounded.

In each door A A A there are four springcontacts K, L, M, and N, from which the wires cl and e extend over the door-that is, within the paneling the ends of the wire (1 being connected with the spring-contacts K and M and the ends of the wire a with the contacts L and N. The fixed contacts K are connected with one pole of the magnet F by a wire f, and the fixed contacts L are connected by a wire 9 with the other pole of the magnet F. The fixed contacts M and N are connected by the wires h and m, respectively, with the poles of the battery B. As long as the circuit through the wires d c in the door, the spring-contacts K L M N, and the wires f g h m, and the battery B remain unbroken the armature H remains attracted, and the circuit of the local or bell battery remains open, and consequently the bell D is not sounded; but as soon as the circuit through the wires in the door, the contacts, the battery B, and the magnet F is broken the armature I-I drops and the local or bell battery circuit is closed, and the bell D is sounded.

When more than one door or closure is to be included in the line, the wiring in each door is the same as described; but the outer or fixed contact of one end of the wiring of one door is connected with the opposite end of the wiring in the next door, as represented by the wires (1 e d e", and the battery B connects with the outer ends of the wiring in the last door, as shown. For the purpose of discovering which door gives the alarm I provide six switches, (marked, respectively, 0 O P P R R the contact-button of each switch being connected with the lever of the adjacent one, as represented by the wires 0 0 p 12 the contact buttons of the last switches being connected with the terminals of the battery B, and the lever of each switch being connected with the corresponding wiring of one door, respectively, as represented by the wires i If s s and w 10 respectively. The switches O O P I R are normally open, and the circuit through any doorfor example, A will be as follows: from one terminal of the battery B through the wire m through the wiring e of the door A the wire 6 to the wiring e of the door A the wire a, the wiring e of the door A, the wire 9, the magnet F, the wire f, the wiring (Z of the door A, the wire d, the wiring d of the door A the wire (1 the wiring (Z of the door A and the wire it to the other terminal of the battery B, and in like manner for any more doors or closures. If the door A for example, is opened or a panel cut, this circuit, as described above, is broken, and the bell D is sounded, as described above. It now remains to discover at which door or by which door the circuit was broken. If now the switches O O P P R R are all closed and the armature H is raised, it will be held in place as the circuit of the battery B remains closed as follows: from one teiminal of the battery B through the wire m, the wiring e in the door A which is intact, the wire w closed switches R P 0 the wire t g, the magnet F, the wire f, the wire t, the closed switches O P R back to the battery. If the switches R R areopened, this will not break this circuit, as it remains closed from the battery B, the wire 'm, the wiring e of the door A which is intact, the wire W, the closed switches P 0 the wires t g, the magnet F, the wires f t, the closed switches P O, the wire w, the wiring d of the door A back to the battery. If the switches R R remain open and the switches O O are also opened, the circuit remains unbroken as follows: from the battery B, wire m, the wiring of the door A which is intact, the wire W, the closed switch P, the wire 8 the wiring e of the door A, which is intact, the wire 9, magnet F, wire f, the wiring d of the door A, the wire 8, the closed switch P, the wire w, the wiring (Z of the door A which is intact, and the wire it back to the battery. If now the switches P or P are opened, the circuit is broken and the bell is sounded, as the ar mature I-I drops as soon as either switch P P is opened, thus indicating that the break is in the door connected with the switches P P, so that whenever an alarm is sounded it is only necessary to close all the switches O O P P R R and then open them successively, and as soon as a switch connected with the door at which the circuit is broken is opened the alarm will be sounded. If the wirings d and e are brought in contact in tampering withany door, the circuit will also be broken, as thereby a short circuit is formed which cuts out the connection with the magnet F, and the armature of the latter drops. To discover any tampering with a door, &c., by short-circuiting, the two wirings d e are required; but for giving by a signal by mere breaking of the closed-circuit line the wire (1 or the wiring 6 will suffice, of

course,'with its corresponding set of switches O P R or O P R If the wiring 6 only is used, the switches O P R can be dispensed with, and the battery B is connected, as

shown by the dotted line S, and the connection r is omitted. If, on the other hand, the wiringd only is used, the connection S (shown in dotted lines) is made and the connection 9" is dispensed with, as are also the switches O P R The circuits and the efiiects of the opening and closing switches remain practically the same as previously described. If the circuit in any door or other closure is broken, this door can be readily cut out by means of its switch or switches without interfering in any way with the balance of the line, which remains operative.

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

1. In a burglar alarm, the combination with a battery and electromagnet, and a circuit including the battery and the magnet, of separate wiring for one or more separate closures included within said circuit, and a separate switch for each closure, which switches serve for closing or opening the circuits of said closures, and means operated by said ma net for closing a local battery,.substantialIy as set forth.

2. In a burglaralarm, the combination with a battery and an electromagnet, and a circuit, in which circuit the battery and electromagnet are included, of two separate wirings'for a closure, which separate wirings are included in said circuit, and a separate switch for each wiring of each closure, which switches serve for closing or opening the circuits of said closure and means operated by said magnet for closing a local circuit, substantially as set forth.

3. In a burglaralarm, the combination with a battery and an electromagnet, and a circuit in which the battery and magnet are included, two separate wirings for a closure, which separate wirings are both in said circuit, and a separate switch for each wiring of said closure, which switches serve for closing or opening the circuits of said closure, and means operated by said magnet for closing a local battery, substantially as set forth.

4. In a burglaralarm, the combination with a battery and electromagnet, and a circuit including the battery and the magnet, of two independent wirings for each of a series of closures, two switches for each closure, one switch of each pair being connected with one wiring of the closure, and the other switch of the pair being connected with the other wiring of the closure, and the circuit of both wirings of the closures being within the circuit of the aforesaid battery, and means operated by said electromagnet for closing a local circuit, substantially as set forth. 7

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

WILLIAM N. FAWOETT.

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