US23215A - Burglar-alarm - Google Patents

Description

R. M. CAMPBELL.

Burglar Alarm.

`Patented March 8, 1859.

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UNITED STATES PATENT OFFICE.

ROBERT M. CAMPBELL, OF EAST CAMBRIDGE, MASSACHUSETTS, ASSIGNOR TO \VILLIAM G. CROMBIE, OF BOSTON, MASSACHUSETTS.

BURGLAR-ALARM.

Specification of Letters Patent No. 23,215, dated March 8, 1859.

To all whom it may concern:

Be it known that I, ROBERT M. CAMPBELL, of East Cambridge, in the county of Middlesex and State of Massachusetts, have in vented an Improved Burglar-Alarm; and I do hereby declare that the same is fully described and represented in the following specification and the accompanying' drawings, of which- Figure l, denotes a top view, Fig. 2, a front elevation; Fig. 3, a rear elevation; Fig. A, a vertical and transverse section; and Fig. 5, a front end elevation of the same.

My invention is intended to be applied to a door and its casing and so as to operate, when an attempt is made to open the door, as to cause the explosion of a percussion cap and thereby sound an alarm by which a person within an apartment provided with such door may be informed of an attempt being made to enter the said apartment or to open its door.

In the drawings, A, denotes a circular box or case, of what may be termed a percussion lock. vWithin the said case there is a percussion ,hammer or striker, B, and a nipple or percussion cap receiver', C, the hammer being forced toward the same by means of a spring, D.

A spring catch or trigger E is arranged within the case, and in front of the forward end of the hammer and is made to project a short distance rearward through the case, its upper end being furnished with a knob, a. This spring catch or trigger is constructed with a notch or recess, Z), to receive a stud, c, projecting from the front end of th-e hammer, the reception taking place, when the hammer is cocked or after being raised to full cock, and such parts serving to maintain the striker at cock.

A sliding fastener, G, is applied to the percussion alarm lock in such manner not only to be capable of being slid or moved fronrthe circumference toward the side of the case, A, and vice versa, but of being folded down flatwise upon the case, as well as of being opened at right angles thereto. To this end, the fastener G is applied to a bar or plate, H, affixed to the rear side of the case A, or arranged thereon, as shown .in the drawings, such bar being made to extend through an opening (I, made through the fastener Gr. such fastener being secured in the plate H, by ahinge pin, c,

which passes downward through the fastener and in rear of the part H, and so as to enable the fastener not only to be slid or moved on the said part H, but of being either turned down parallel to the case A, or at right angles thereto as before mentioned.

The fastener, G, consists of two spring plates f, g, arranged with respect to one another as shown in the drawings, or it may be a rigid plate having a spring applied to it and in such manner that when the two are within the joint or space between the edge of a door and its casing, the spring by resting or pressing against-the door shall force the plate in close Contact with the door casin g, that side of the fastener which is in contact with the casing being furnished with teeth or spurs L, L, to enter the same. The rear of the case A, is furnished with a small turning catch or button, z', applied in such manner as to be capable of being turned over upon the fastener, G, so as to hold it in place, when it is laid down flatwise upon its case.

In the application of the above described alarm apparatus to a door and its casing, after the nipple C, has been provided with a percussion cap, and the hammer B, has been cocked, the sliding fastener G, is to be moved outward to the outer edge of the case A, and arranged to project at, or about atV a right angle thereto. In this position of the fastener, Gr, its inner surface or its spring should be placed against the inner edge of the door casing and the door should be afterward closed upon the fastener so as to secure .it firmly within the joint between the edge of the door and its casing. This having been accomplished, the case, A, should be moved forward in such manner as to carry the fastener toward the middle of the case, and cause the case to lap over both door and case, and in such manner that the knob, a, shall come directly in front of the door. Under this state of the parts, should an attempt be made to open the door, it will press against the knob a, and in consequence of the case A being firmly held in position by the fastener, G, and the door casing, the trigger catch E, will be moved so as to discharge the hammer or striker and permit its spring to throw it down upon the percussion cap and effect the explosion of the same, the noise of which will produce the necessary alarm. Furthermore the case and sliderserve as a look to prevent the door from being opened until the Case may be moved laterally.

5 I do not claim a percussion alarm, a gimlet or any such means of fastening the same to a door casing; but

hat I do claim is- The application of the spring Jfastener G,

to the alarm or its ease so as to be capable 10 of sliding,` and turning With reference to the same substantially in manner as specified.

In testimony whereof, I have hereunto set my signature.

R. M. CAMPBELL.4 '1i Witnesses:

R. H. EDDY, F. P. HALE, Jr.

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