US1415874A - Automatic alarm - Google Patents

Description

S. HICKEY.

AUTOMATIC ALARM. APPLICATHJN HLED AUG.24, 19 20.,

Patented-May 16, 1922.

w a k m UNITED STATES PATENT AUTOMATIC ALARM.

Specification of Le tters Patent.

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Application filed August 24, 1920. Serial No. 405,653.

To all whom it may concern:

Be 1t known that 1, SIMON Hickey, a sub- 1ectof the King or Great Britain and Ireland,.residing at Arcadia, Harrington Street, lvlarri ckville, in the State of New South lVales, Commonwealth of Australia, have invented certain new and useful Improvements in Automatic Alarms, of which the following is a specification.

- The object of this invention is to provide a simple, effective and inexpensive device for calling attention to the surreptitious opening of a door or window or the unauthorized interference with a movable object and for similar purposes.

The essential :features of my device are a clockwork mechanism (of the nature hereinafter described) designed to operate an alarm of ordinary construction, a centrally pivoted detent lever controlling the movement of the hammer and releasable by the pulling of a flexible cord or chain connected thereto for the purpose herein set forth.

The clockwork mechanism resembling that of an ordinary clock, actuates a saw-toothed wheel geared to an escapement device the pallet of which is centrally mounted on an oscillating element which also carries the shank of the hammer.

As soon as the spring is wound up the mechanism rotates the toothed wheel which in turn actuates an escapement oscillating the pivot-pi11 and causing the hammer to strike the gong.

The detent lever carries on one end a retaining pin designed to engage with an arm.

(projecting from said pivot pin) in such a manner as to hold the same and prevent its oscillation thus controlling and preventing the gong from sounding.

But in order that the invention may be more clearly understood I will refer tothe accompanying drawings in which- Fig. 1 is a perspective View of my device enclosed in a convenient box or casing with the detent lever pulled off and the parts free to operate.

Fig. 2 is a front elevation showing the parts locked.

Fig. 3 is side elevation showing the easing in section and with the parts in the locked position.

The clockwork mechanism is of ordinary construction consisting of a winding stem A, spring A toothed wheel A pawl A and ratchet wheel At The toothed wheel gears with a pinion B on a pivot-pin 13 carryin a serrated wheel B which is engaged by thl; pallet C centrally fixed on the sleeve D oscillating about a standard D. Said sleeve also carries the shank E of hammer lll. l rom the opposite side of the sleeve D 61!- tends an arm E which may be a continuation oi? the hammer shank E. The detent lever F s centrally pivoted at G on the topplate H, and carries at one end the retaining pin F designed to engage with and hold the arm E as shown in Fig. 2. The mechamsm above described is mounted upon a base N The cords J and J are connected respectively to the ends of the detent lever and are so disposed that a pull. on either 01 them. will swing the end of the lever carrying the retaining pin clear of the arm IE and, releasing same, permit the clockwork mechanism to actuate the oscillating pin D.

The cord K is for the purpose of pulling the detent lever on (i. c. with the retain ing pin F engaging arm 13 when the device is placed in a position not easily accessible for manipulation but would not be required under other circumstances, similarly the weight L is provided for the purpose of being placed in a position where an unauthorized movement would cause it to drop and pull the detent lever ofi" causing the alarm to operate.

The operation of my invention is as follows The mechanism haviiig been wound up, the detent lever is brought into the holding position (i. e. that in which the retainingpin is in contact with the arm FF) and one or both oil the cords J. J so fastened to a door or other movable object the movement oil? which :it is desired to detect, that such movement will cause one of said cords to pull the said lever oil so that the retaining pin is withdrawn from contact with the arm E The mechanism being thus freed, oscillates the sleeve D and causes the hammer to come into striking contact with the gong M thus giving the required alarm.

What I claim and desire to secure by Letters Patent is 1. An alarm device, comprising in combination spring actuated mechanism, means for tensioning the spring, a serrated wheel actuated by said mechanism, a pallet centrally mounted on an oscillating sleeve and actuated by the serrated wheel, a hammershank projecting from said sleeve, a head on said shank, a stop arm for said shank, a gong associated with said head, a detent lever pivoted at a point between its ends, and having a member to engage said stop arm and restrain said hammer shank from operating when said detent lever is in one position and a cord connected to the detent lever and so directed that a pull thereon Will move said lever to the off position.

2. An alarm device, comprising in combination a base, a plate supported thereon, spring actuated mechanism located between said base and plate, means for tensioning the spring, a spindle having end bearings in said base and plate and rotated by said mechanism, a serrated Wheel on said spindle, an oscillating sleeve about a standard between said base and plate, a hammer shank extending in one direction and an arm extending in another direction from said sleeve, a head on said hammer shank, a gong associated with said head and mounted on the base, a pallet aflixed on said sleeve, said pallet engaging said serrated Wheel and being oscillated thereby to effect oscillation of said hammer-shank and arm, a detent lever pivoted on said plate, and having means engaging said arm to prevent oscillation thereof when the lever is in one extreme position, a cord connected to said lever and a Weight on the end of said cord, said Weight when hanging on said cord pulling said lever from said extreme position and releasing the mechanism to operate the hammer and sound the gong as herein set forth.

Signed at Sydney, N. S. V. this nineteenth day of July A. D. 1920.

SIMON HICKEY.

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