US286888A

US286888A - Alvah wiswall

Info

Publication number: US286888A
Authority: US
Publication date: 1883-10-16
Anticipated expiration: 1900-10-16

Description

A. WISWALL.

ELECTRO MAGNETIC ALARM.

(No Mqdel.)

Patented Oct. 16, 1883.l

. Erin-IV #WWW/ UNITED STATES PATENT OEEICE.

ALV AH VISVALL, OF CINCINNATI, OHIO, ASSIGNOR, BY DIRECT AND MESNE ASSIGNMENTS, TO FREDERICK VOELCKEL, OF SAME PLACE.

ELECTRO-MAGNETIC ALARM.

SPECIFICATION forming part of Letters Patent No. 286,888, dated October 16, 1883.

(No model.)

.To all whom t may concern:

Be it known that I, ALvAII VIswALL, of Cincinnati, Hamilton county, Ohio, have invented a new and useful Improvement in Electro-Magnetic Alarms, of which the following is a specification.'

My invention relates to the class of devices in which the act of alighting or walking across a particular spot is made known at a dist-ant station by an electro-magnetic alarm.

Using any of the well-known electro-mag netic alarms and the ordinary means of electrical comiminication, my invention is direct ed to a novel mechanical device whereby the I 5. pressure of the passers foot is made effective to close or to open the circuit, according to whether a normally-open or normally-closed circuit is employed. This mechanical device consists, essentially, of an india-rubber tube, 2O at one or both ends of which is an expansible sac or bladder, whose inflation by the air driven into it by the pressure of the intruders foot causes contact of the wire terminals, so as to complete the circuit, and by so doing bring 2 5 into activity the alarm by any of the familiar modes.

In thc accompanying drawings, Figure l is a ground plan of a premises provided with my improvement. Figs. 2 and 3 are longitudinal 3o sections of the circuit-maker in its open and closed conditions, respectively. Figs. 4 and 5 are end views of the device shown in Figs. 2 and 3, respectively. Figs. 6 and 7 are longitudinal and transverse sections, respectively,

g, 5 of a modification of my circuit-maker.

A may represent an apartment protected by my device. B B B represent india-rubber tubing, preferably closed at one end. The other end of the tubing enters a sac or bladder, C,

4o of india-rubber, oil-silk, or any other suitable flexible impervious material. Likewise secured to said tube end -is a metallic sheath, D,

whichis in electrical communication with one of the battery-wires E. Also secured to tube B, but insulated from vthe sheath D, is a metallic spring, F, whose resilience (except when said spring is pressed forcibly outward) maintains it out of contact with the sheath D. Compression npon the tubing B (such as would be made by the foot of a person passing over it) 5o forces air into the sac C, which, expanding the latter, causes it to force the spring F outward, so as to bring it in contact with the sheath D, and by thus completing the circuit to sound the distant alarm.

Various forms of circuit-closers may, obviously, be combined with such tubing and sac. For example, a form may be given to the spring such as shown in Figs. 6 and 7, which show such a form in its closed condition.

The tubing E may be made to assume the undulating form shown or a coiled or other arrangement by a fastening of twine or netting, canvas, or other flexible fabric, or it may remain unattached and be simply laid underneath a carpet or rug or other floor-covering.

vWhen employed in connection with a closed circuit, all the systems of tubing may, if desired, be united in one series, so as to save wire. l

' I claim as new and of my inventionw In an electric burglar-alarm, the flexible airtube B, forming a mat, in combination with an expansible sacconnected thereto, and a eircuit closer or opener having contact-pieces, the 75 sac to act on one of the contact-pieces, as set forth.

In testimony of which invention I hereunto set my hand. Y

ALVA H VISWALL.

Attest:

GEO. H. KNIGHT, SAME. S. CARPENTER.