US296646A - tallman - Google Patents

Description

(N0 Model.)

' G. W. TALLMAN.

BURGLAR ALARM.

N0. 296,646. Patented Apr. 8, 1884.

tin rrni'a tiT Parent @rrrca GEORGE W. TALLMAN, on new YORK, 1v. Y.

BURGLAR-ALARM.

' SPECIFICATION forming part of Letters Patent No. 296,646, dated April 8, 1884.

Application filed January 16, 1884. (No model.)

'and useful Improvements in Burglar-Alarms,

of which the following is a specification, ref

erence being had therein to the accompanying drawings.

My invention relates to improvements in burglar-alarms, the object of which is to pro vide a cheap and simple device which can be readily attached to the shank or stem of the ordinary door-knob.

My invention consists of a plate or bar adapted to be readily attached to or detached from the shank or spindle of the ordinary doorknob, to which is pivoted a gravitating pendent or swinging extension, in which the spring and spring-actuated rod or hammer for striking the blow on the percussion-cap or other fulrninate to produce the alarm are located, said rod or hammer being released and caused to strike the blow by the, turning of the door-knob, as will more fully appear.

Figure l is a front view of my device in position ready for giving the alarm. Fig. 2

is a side view, partlyin section, of my device as attached to the shank of the door-knob. Fig. 3 is a front view of the upper'portion of my device, in which a spring is used instead of a thumbscrew for attaching my device to the shank of the door-knob.

A is a metal plate, the upper end of which is cut away to form a recess to embrace the shank of the doorknob, and having hinged thereto a jaw, 13, which is also cut away to re ceive the shank of the door-knob. The jaw B may be kept in place and in contact with the shank of the door knob by means of thumb-screw G, or by means of a fiat spring, D, as shown in Fig. 3. By either of these appliances the device is readily attached to or detached from the shank of the door-knob.

E is a gravitating pendant loosely pivoted to the plates at a by means of the screwbolt F, and the lower portion of the pendant E is made heavier, so that the pendant will at all times hang in a vertical line. The pendant E is provided with a central hole, E, in

which is placed the rod or hammer G. The lower end of the rod G is provided with a shoulder, 2), against which one end of the spiral spring G rests or impinges, the other end Of the spiral spring being held in the central hole and around the rod G by means of the -screw-nut H, which is secured in the top of the pendant, so that by raising the rod or hammer the spring will be contracted, and on suddenly releasing said rod it will be thrust downward by the expansive force of the spring.

I is a button loosely secured to the top of the rod or hammer G, which, when the rod is raised, is turned into the aperture K, formed in the plate A, and by which means the rod or hammer is held in an elevated position.

L is a cavity formed in the lower end of the pendant E, and joins the central aperture or hole, E, at a right angle. The object of this cavity is to receive or hold the ordinary paper fulminate, as shown at c, Fig. 1, or through which a percussion-cap can be placedon the lower end of the rod or hammer G.

The operation of my device is as follows: The plate A having been secured to the shank of the door-knob, the hammer is raised and the button turned into the aperture K, and the fulminate c placed in the cavity L, so as to be struck by the lower end of the rod or hammer G.

As before stated, the tendency of the pendant E is to hang in a vertical line, so that when the doorknob is turned the plate A is turned at an angle. This releases the button I from the opening K, and the spring forces the rod down onto the cap a, which explodes it and causes an alarm.

The advantages of my device are numerous and obvious. It is. cheap and light, can be carried by travelers without inconvenience, is composed of but: few parts, and not liable to get out of order. It can be attached to the shank or stem of any ordinary door-knob, is

not dangerous, and is an article which will.

recommend itself to the traveling public.

I am awarethat a cylinder containing a spring-operated piston for striking a blow on a percussion-cap is not new, said piston being held by a catch which is released by a cord attached thereto, said cord being passed over roo a pin at the upper portion of the door, the cord being pushed off of the pin by the opening of the door, and thejar of the falling device on the cord serving to pull back the catch and release the piston.

I am also aware that it is not new to attach a gong or series of gongs to a door-knob by means of an arm,so that the turning of the door-knob will release a clock mechanism which operates the hammer for sounding the gong, and such I do not claim.

Having thus described my invention, what I claim, and desire to secure by Letters Patent, 1s

1. A burglar-alarm consisting of a plate adapted to be attached to the shank of the door-knob, a gravitating pendant enlarged at its lower end, as described, and provided with a spring-actuated hammer, said pendant being pivoted to said plate, as set forth.

2. A burglar-alarm consisting of a graviin the arm, by which the device is secured to the shank of the door-knob, as described,

whereby the partial rotation of the door-knob will release the button, and the rod or hammer will be forced downward on the cap or other fulrninate, as set forth.

3. In a burglar-alarm, a plate, A, adapted to be secured to the shank of a door-knob, and furnished with an opening, K, in combination with the gravitating pendant E, spring G, rod G, nut H, and button I, asset forth.

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

GEORGE W. 'IALLMAN.

WVitnesses:

R0131. AULn, WM. MOBURNIE.

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