US1065861A - Burglar-alarm. - Google Patents

Description

G. A. BREWSTER.

BURGLAR ALARM.

APPLIOATION FILED MAY 17, 1911.

1,065,861 Patented June 24,1913.

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GEORGE A. BREWSTER, OF NEW YORK, N. Y.

BURGLAR-ALARM.

To aZZ whom it may concern Be it known that I, GEORGE A. Bnnwsrnn, a citizen of the United States, and a resident of the city of New York, borough of Brooklyn, in the county of Kings and State of New York, have invented a new and Improved Burglar-rilarm, of which the following is a full, clear, and exact description.

Among the principal objects which the present invention has in view is to provide an alarm of the character mentioned adapt ed for temporary installation on the knob of doors and in conjunction with the keys for locking same.

ith this object in view the invention consists in providing an attachment quickly and readily installed upon a door knob or other rotary closure device employed for opening doors or windows.

One embodiment of the present invention is disclosed in the structure illustrated in the accompanying drawings, in which like characters of reference denote corresponding parts in all the views, and in which- Figure 1 is a detail view in front elevation of a door escutcheon plate showing in conjunction therewith a circuit closing attachment constructed and arranged in accordance with the present invention; Fig. 2 is a detail view, on an enlarged scale, of the construction shown in Fig. 1; Fig. 3 is a cross section taken on the line 4-4 in Fig. 3.

It is the principal purpose of the circuit closing attachment shown in Figs. 1, 2 and 3 of the drawings that the movement of the door knob necessary to open the door should close the contact and complete the electric circuit for actuating the bell 19. The attachment is provided with a clamp which is formed of two side pieces 24, these being bowed intermediate their ends and pivotally connected at 25 each to the other. To insulate the side pieces 24 from the shank 26 of the door knob 27 the same are covered at and adjacent the bowed portion with rubber tubing 28. Loosely passed through a perforation in one of the side pieces 24 and thread engaged with the other side piece 24 is a screw 29, by manipulating the knurled head 30 of which the side pieces 24, 24 are drawn together, the collar 31 rigidly formed on the screw 29 serving to move the free side 24 toward the engaged side. Intermediate the side pieces 24 and encircling the screw 29 is a spiral spring 32, the ofiice of which is to separate the side pieces 24.

Specification of letters Patent.

Application filed May 17,1911.

Patented June 24, 1913.

Serial No. 627,666.

Fixedly connected with one of the side pieces 24 is a suspension hanging frame 33. The frame 33 is provided with a binding post 34 under the screw whereof is inserted the end of one of the wire mains 20. Mounted at the end of the frame 33 is a bracket 36. The bracket 36 is shaped as shown in Fig. 3 to form an elliptical loop 37 to surround the pendant 38. The bracket 36 has an upturned extension adapted for disposition parallel with the frame 33 and attachable thereto by means of a screw stud 39, the binding screw 40 serving to hold the wire 21. Interposed between the stud 39 and the metallic parts connected therewith and the frame 33 is an insulating block 35.

The pendant 38 is weighted at the lower end to insure the vertical position of the said pendant, the same being hung on a pivot 41 which is set out from a short bracket 42 fixedly mounted on the frame 33.

iVhen installing the device the side pieces 24 are spread to pass the free ends over the shank of the door knob. The screw 29 is then manipulated to draw the side pieces together, the shank 26 resting between the bowed sections of the said pieces. The device is so adjusted that the pendant 38 hangs substantially at the center of the loop 37. It will be seen that if the switch 16 be now closed and the door knob be turned to open the door, the frame 33 and loop of the bracket 36 will swing about the center and the loop 37 be brought in contact with the pendant 38. The pendant 38 being electrically in contactwith the frame 33, and the frame 33 in electrical contact with the wire 20, the circuit for actuating the bell 19 is established when the pendant 38 touches the side of the loop 37, and this for the reason that the loop 37 is part of the circuit being electrically connected with the wire 21. The loop 37 being relatively small it will be seen that before the knob 27 is sufficiently turned to release the door the alarm has been sounded. In the operation of the device the alarm will cause the interloper to suspend operations, when the knob 27, resuming its normal position, the pendant 38 becomes disengaged from the loop 37. The above described action will reoccur should a second attempt be made, thus effecting by the employment of an alarm of this character a purpose different from that usually effected, where the alarm operates once and once only.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is In a burglar alarm, the combination of an elongated frame having at one end thereof aclamp, the jaws whereof are electrically in sulated; an operating screw for said jaws; an insulating block permanently mounted on said frame at the end thereof opposite said clamp; a closed metal ring bracket rigidly mounted 011 said block; a binding post mounted on said frame in electrical contact therewith; a second binding post mounted upon said block, having electrical contact with said bracket, said binding posts being adapted to receive the terminals of a metallic electric circuit; and a metallic endweighted pendulum pivotally mounted on said frame and extending through said bracket in the closed ring thereof, said pendulum being adapted to maintain its vertical arrangement when said frame is moved from its normal position, and to be engaged by said bracket when said frame is so moved, to thereby complete the electric circuit incorporating said binding posts.

In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.

GEORGE A. BREWSTER.

lVitnesses E. F. Mnnooon, J. P. DAVIS.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.

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