US98078A - Improved burglar-alarm - Google Patents

Description

M. LUNT.

Burglar Alarm.

Patented Dec. 21, 1869.

site MOSES LUNT, 0F CAMBRIDGEPORT, MASSACHUSETTS.

Letters Patent No. 98,078, dated December 21, 1869.

. IMPROVE!) BURG-LAR-ALARM.

The Schedule referred to in these Letters Patent and making part o the same To all whom it may concern Be it known that'I, MOSES LUNT, of Cambridgeport,in the c ouuty of Middlesex, and State of Massachusetts, have invented an Improved Burglar-Alarm,

.of which the following is a full, clear, and exact del seription, reference being had to the and inexpensive apparatus for instantly giving notice of any attempt to open a door from the outside; and

My invention consists in a frame, provided with one or more tappet-wheels, which are caused to revolve and act upon one or more springs by the descent of a weight, suspended by a hook from the inside of the door-handle, over which the apparatus is hung, the

handle, on heilig turned from the outside, causing the hook to drop oii and release the weight, which will then descend, and raise the alarm.

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it out. v

In the said drawings- A represents the inside knob or handle of a door, over which, by means of a strap, a, is bung a frame, B, consisting of two parallel strips, b, united at their bottoms by a cross-bar, c.

The upper ends ofthe strips of the frame are provided with enlargements, d, in bearings, in which a shaft, C, is revolved by operating a crank, I).

The portion of the shaft C within the space between the parallel strips b, is provided with a drum or pulley, E, and two tappet-wheels, G H, one on each side ci it.

This cord is led through a cross-piece, j, and is wound around the pulley by turning'the crank'D, thus drawing up the weight.

Within the interior of each of the. parallel strips b, is formed a groove, for the reception, and to allow of the sliding of a' thin bifurcated strip of wood, Ii, the portions g h of which act as springs, and bear upon the cross-piece f, while their upper extremities 3 4 extend up into the path of the tappet-wheels, so that when -t-heir cogs or projections t' are brought against the extremities 3 4, the springs q It yield thereto, and are pressed back thereby until the coge pass up and away from contact with the extremities 3 4, when the springs g h instantly regain their original position, re-

turning to their bearings upon the strip f so quickly i and forcibly as to produce a succession of' loud reports or noises.

L is a hook, by which the-weight I is supende'd from the inside knob ofthe door when the weight is wound up, as seen, in lig. 1.

I will now describe the manner of operating and ap-l plying iny alarm to the door of a house. y

The bifurcated strip K is' slid down in its grooves until the upper extremities 3 4 of the springs g h,v are below the path of revolution 'of the tappet-whcels Gr H, when the cord e is wound around the pulley E, and the weight I raised, by turning the crank I) in the direction ofthe arrow 5.

The bifurcated strip K is' now slid up within its grooves till one of theextrernities 3 or 4 of the springsg h is brought in contact with a cog, t', of one of the tappet-wheels G H.

The frame is now hung over the inside knob of the door, by means ofthe strap a, and the weight I is suspended therefrom, by catching the hook L over thc top of the knob A.

When a burglar or intruder applies his hand to the ont'side knob or handle, and revolves the/same for the purpose of entering, the hookL drops off the inside knob A, when the weight, being no longer supported, descends by its gravity, and causes the revolution ot' the tappet-wheels (iA H in the direction of the arrow 6, by which means the springs g h are thrown back from their bearing on the cross-piece f,.and on the passage of the cogs z' away from contact with them, the springs g h rapidly and forcibly strike the crosspiece f in returning to their original position, thusproducing a noise or alarm, which wakens or notifies the occupant ofthe room.

Instead ot' a weight, i, a coiled spring, applied to the pulley E o r shaftC, may be employed, the spring being released, so as to cause the revolution ofthe tappet-wheels G H, and produce the desired alarm.

What I claim asniy invention, and desire to secure by Letters-Patent, is

A burglar-alarm, consisting essentially of a frame,

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