US256145A

US256145A - Burglar-alarm

Info

Publication number: US256145A
Authority: US
Publication date: 1882-04-11
Anticipated expiration: 1899-04-11

Description

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, gaged with pinion e.

UNITED STATES JOSEPH V. KNIGHT, OF

PATENT OFFICE.-

LYNN, MASSACHUSETTS.

SPECIFICATION forming part of Letters Patent No. 256,145, dated April 11, 1882,

` Application filed January 524, 1882. (No model.)

To all whom it may concern:

Be it known that I, JOS. V. KNIGHT, of Lynn, county of Essex, and Commonwealth of Massachusetts, have invented certain new and useful Improvements in Burglar-Alarms; and I do hereby declarethat the followingis a full, clear, and exact description of the same.

The object of this invention is to obtain a simple, cheap, and reliable automatic alarmbell for use in stores, offices, and houses, for application to doors, shutters, and other swin ging devices in such manner that when the door or shutter, as the case may be, is opened the movingof the same will release a hammer and cause the bell to sound and give the desired alarm. f

The invention consists in matters of construction hereinafter fully described and claimed.

In the accompanying drawings, Figure l shows a side elevation ot' myimproved burglaralarm. Fig. 2 is the same as Fig. l with the face-plate removed to show the inside mechanism. Fig. 3 shows the alarm in combination with a door.

The case A is provided with three cross-bars, B, O, and D,designed to support the operative mechanism. The pinion e is pivoted to the cross-bari), and is revolved by the cross-sprin g d, arranged about its axle, as shown in Fig. 2. Said pinion eengageswith and turnsthe smaller pinion a, thereby giving motion to the escapewheelf,whieh in'turn operates the escapement h so as to reciprocate the hammer fn. and sound the bell E, all in an obvious manner. A pawl has its end pivoted to the ear 2 and engages with the pinion e, so as to lock the pinion when desired, as referred to hereinafter. The lever-ratchet 3 is centrally pivoted to the cross-bar O. Said ratchet engages at one end with the pinion e and at its opposite end with the button 4, and is disengaged from the pinion e by operation of the spring 5. Fig. 2 shows the mechanism set ready foran alarm, in which condition the ratchet 3 appears en-V The spring 5, being depressed by the ratchet, is prevented from acting so long as the end of the ratchet is held down by the button 4.

The parts are protected from dust or injury by a face-plate, which is perforated, as shown in Fig. l, being thereby better-adapted to the transmission of sou'nd.

The alarm is. attached to the door or other swing device by screws, as shown in Fig. 3. It is set for operation through suitable holes, 6, 7, and 8, made in plate H. By reason of a key fitted in an obvious manner the spring d is first wound up. lhe ratchet 3 is then depressed till its inner end engages with the pinion c, whereupon the door is closed with the outer end of the ratchet 3 under the button 4. It will now be' understood that should the door be opened sufficiently to move the end of ratchet operate to release the pinion e, and the alarm would be given. i

It' it is desired to open the door without giving an alarm, it is only necessary to insert the key in hole 6 and throw the ratchet into engagement with the pinion e, whereupon the door may be opened,and althoughA the ratchet 3 is disengaged from the pinion c,'tl1e pinion is still locked bythe ratchet 1, so that no alarm will be sounded.

From the foregoing it will appear that by this my invention I am enabled to make a compact, simple, and reliable alarm-bell suitable for application to doors or other swinging devices where it is desired that an alarm should be given upon the opening of the Same.

Having thus described my invention, what I claim is 1. In a burglaralarm, the combination of a clock-spring, gearing e af, an escapement, h, a hammer, and a bell with a pivoted springpawl, 3, and a stop or button, 4, all constructed and adapted to be operated substantially as described.

the pinion e, the spring, gearing c af, escapement h, hammer, and bell with the Spring-pawl 3, the button 4, and the locking-pawl 1, substantially as described.

In testimony whereof I have signed this specifieationin presence of two witnesses.

JOS. V. KNIGHT.

Witnesses: l

C. V. TUTTLE,

R. M. JOHNSON.

3 away from the button 4 the spring 5 would 2. In a burglar-alarm, the combination of 9o