US535100A - Burglar-alarm for glass doors - Google Patents

Description

Unirse Sterns JAMES B. GILL, OF SAN FRANCISCO, CALIFORNIA.

BURGLAR-ALARIVI FOR GLASS DOORS.

SPECIFICATION forming part of Letters Patent No. 535,100, dated March 5, 1 895. Application tiled February 27, 1893.A Serial No. 463,800. (No model.)

To all whom t may concern.-

Be it known that I, JAMES B. GILL, a citi- Zen of the United States, residing in the city and county of San Francisco, State of California, have invented a new and useful Burglar- Alarm for Glass Doors, Windows, &c.,of which the following is a specification.

The object of my invention is to provide a means for immediate announcement of attempted burglaries through glass-doors, plateglass and other windows, sky-lights, transoms, duc. I attain this object by the means illustrated in the accompanying drawings which form part of this specification, and in which- Figure l represents an inside view of a large plate-glass window embodying my invention and showing a thin strip of metal around the border of the plate with connecting Wires and parts. Fig. 2 is a view in perspective of a pad by which the Wires are secured to the border.

A represents a thin narrow strip or film of silver or other conductor of electricity connected to the face of the glass by some adhesive substance which extends all around the glass near the frame in an unbroken line save at one corner preferably the upper corner.

To e'ech end'of the film or strip of conducting metal I connect a pad B, B, (best shown in Fig. 2) which is composed of a narrow strip of blotting paper interiorly lined With a film or strip of the same substance as the film or strip around the glass pane is composed of, and of the same width as that of the blotting pad. The pads are held in position and in contact with the film by means of springs B fastenedto the Window-frame. These pads B,B, are connected by means of the .wires C, CX with a closed battery circuit of a burglaralarm appliance (not shown) which causes an alarm to sound when the circuit is broken would naturally congregate at such a place as a store front at the sound of broken glass. In such an attempt to gain entrance to a building by cracking or breakingthe pane of glass provided with the safeguard above described it is quite evident that in breaking the glass the lm will also be broken or ruptured and the electric circuit connecting the wires With the burglar alarm will be broken at once.

The film may be of gold, silverquicksilver or other conducting substance and may be made to adhere to the glass in straight border lines as shown in the drawings or be applied in curved lines forming ornamental borders, but under such conditions as that, the border should be continuous and unbroken save and except at one corner as above set forth.

Having thus described my invention, What I claim, and desire to secure by Letters Patent, is-

In a burglar alarm a thin strip or film of metal applied tothe inner face of glass-doors, windows, dac., the continuity of Which is broken and the ends provided With conductive pads composed of -a thin strip of conductive metal inclosed by bibulous paper, connecting with the wires of a battery, as described.

In testimony that I claim the foregoing I have hereunto set my hand and seal.

JAMES B. GILL. [Ls]

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