US1101999A - Burglar-alarm. - Google Patents

Description

UNITED STATES PATENT orrroa.

' WILLIAM E. CLARK, orsamac LAKE, NEW yoax.

Specification of Letters Patent.

Patented June 30, 1914.

Application tlled August 18. 1912. Serial N 0. 715,447.

To all whom it may concern:

Be itknown that I, WILLIAM citizen of the United States, anac Lake, in the county of Franklin and State of New York, have invented certain new and useful Improvements in. Burglar- Alarms, of which the following is a. specification.

-My invention relates to new and useful improvements in burglar alarms and more reven-ting safe breaking in post-offices, st res and other like places.

E. CLARK,

. The invention, is hereinafter described with reference to the accompanying draw- 1 ln the drawing: Figure 1 is a longitudinal sectional View, showing my alarm in position, the wiring being shown diagrammatically; Fig. ,2 is a fragmentary detail sectional view, showing the construction of one of the circuit closers; Figs, 3 and 4 are top lan views, showi'ngthe movable board or p atform which closes the circuits when depressed by the weight of a person'stepping or standing upon thesame; Fig. 5 is a diagrammatic view of the wiring of the alarm,

Corresponding and like parts are referred to in the following description and indicated in all the views of the drawing by the same reference characters.

The preferred embodiment of my invention primarily includes a movable board or platform, designated as a Whole by the numeral 10 and replacing one or more boards in the floor immediately in front of the safe or other property to be protected, an electrically operated alarm device such as a bell 11, circuit closers 12 so positioned as to be operated by. the depression of the board or platform 10, and a plurality of circuits 13 connected between the circuit closers and alarm.

More specifically, one of the boards of the floor 14: 1s removed and adjacent floor timbers 15 are provided in their upper faces with recesses 16 below the opening in the floor thus. formed and the circuit closers 12 are seated in these recesses with their upper faces substantially flush with the upper face of the floor timbers. The opening in the fioor is then closed by means of the board 10 which is provided at either end with a downwardly projecting pin 17 which engages the movable members of the circuit closers, the boardbein residing at Sar-' thereby supported a slight distance above t .e level of the floor.

Each circuit closer includes an insulating I base 18 carrying a fixed contact 19 and a movable contact 20, the latter consisting of a spring arm which spaced relation above the contact 19.- The base member 18 carries a casing 21 and mounted through an opening formed in the top of this casing, is a plunger 22, the inner end of which engages against the upper face of the contact member 20, while the outer end extends substantially flush with the top of the casing which is depressed centrally as "shown. I

The pin 17, previously mentioned, is preferably as shown at 23 and has its outer end provided with a screw driver receiving slot '24 by means of which it may be threaded into the lower face of the board. Because of this, the pin may be readily adjusted to space its free end in any desired distance below in such a manner that w en the board is depressed it will act upon the plunger 22 to move t e contact 20 into engagement with the contact 19 at exactly the same time that the board seats upon the floor timbers at either side of the recess. By careful adjustment of the various parts, the circuit closer and its operating pin 1? ma be so arranged that the board 10 need on y move through a small fraction of an inch to close the circuit, thereby permitting the board to lie almost flush with the surface of the floor and therefore be unnoticeable. The circuit closers are arranged one beneath each end of the board in order to insure the closing of a circuit by the depression of the board, even though the weight applied upon the same is wholly at one end. In Fig. 3 of the drawing, 1 have illust-rated a slightly modified form of construc-.

tion in which several boards are removed from the floor 14 and replaced by a platform composed of a plurality of boards 25 which may be of difi'erent lengths to conform to the manner in which the floor boards are laid and which are secured adjacent their ends to transversely extending cleats or braces 26. In this case, the circuit closers are positioned one under each end of each of these cleats and the pins are of course carried by the cleats and so positioned as to en.- gage'with the circuit closers.

normally extends in The wiring of my improved alarm is very simple. An electric bell or other suitable signaling device 11 is positioned at any suitable point such as in the janitors room, or even in the police station and one terminal of thisbell is connected by a wire 27 with one terminal of a battery 28. A plu-' rality of wires 29 connect the opposite terminal of the battery with the contact members 19 of the circuit closers. Positioned in a convenient place near the bell 11 is a switch including a switch blade 30 swingingly mounted by one end upon a contact member 31 and adapted to be moved in and out of engagement with a second contact 32. A wire 33 connects the free terminal of the bell 11 with-the contact 31, while wires 34 connect the contact 32 with the movable contacts 20 of the circuit closers.

From the foregoing description, the operation of my alarm will be readil understood. In the daytime or at any 0t er time when the alarm is not in use, the switch blade 30 may be swung to open all circuits to the bell but at other times this switch will be closed. The board or platform 10 is preferably positioned immediately in front of the safe in such a manner that any one tampering with the safe will be sure to step upon it and depress it to close one or more of the circuit closers to give the alarm. As. clearly shown in the drawing I have provided an entirely separate and distinct cir-' cuit between each or the circuit closers and the bell and in practice the wires of these 1,10 ace circuits are preferably run through difierentparts of the building so that even though a safe breaker discovers and cuts certain of the wires, the remaining circuits will remain operative.

It will of course be understood that I do not wish in any way to limit myself to the.

application of this alarm as a protection for safes or any other particular ropert-y as it may be employed as a general burglar alarm in houses, the movable board or platform bein positioned at any suitable point as in the all or one of the steps of a flight of stairs.

Having thus described the invention, what is claimed as new is: i

A burglar alarm including a movable floor section, a plurality of pins carried by the floor section and adjustable therein, a plurality of circuit closers carried by thefiloor timbers and each including an operating plunger, the circuit closers being so arranged that each of the pins carried by the floor section engages one of the plungers, an electric signaling device, a plurality of energized circuits connecting the circuit closers and signaling device, and a switch arranged to open and close all of said circuits.

In testimony whereof I afiix my signature in presence of two witnesses.

WILLIAM E. CLARK.

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