US235592A - Alarm for door-knobs - Google Patents

Description

' UNITED STATES PATENT OFFI E.

MICHAEL TRUBY, OF ELKHART, INDIANA.

ALARM FOR DOOR-KNOBS.

SPECIFICATION formingpart of Letters Patent No. 235,592, dated December 14, 1880.

Application filed May 1, 1880. (ModeL) To all whom it may concern:

Be it known that I, MICHAEL TRUBY, of Elkhart, in the county of Elkhart and State of Indiana, have invented a new and valuable Improvement in Alarms for Door-Knobs; and I do hereby declare that the following is a full, clear, and exact description of the construction and operation of the same, reference being had to the annexed drawings, making a part of this specification, and to the letters and figures of reference marked thereon.

Figure 1 of the drawings is a representation of a top View of my improved alarm, and Figs. 2, 3, and 4 are details.

This invention has relation to improvements in alarms for door knobs and latches, which are sounded as often as the knob is turned in the act of retracting the bolt for the purpose of opening the door.

The nature of the invention consists in certain novel combinations of parts, as will be hereinafter more fully set forth.

In the annexed drawings, the letter A designates an ordinary door-knob, by the rotation of which the latch B is retracted. Upon the shank o of this knob is passed a metallic ring, I), which is fixed thereto by means of a screw or otherwise, and which is provided with a projecting'flange, 1), arranged at right angles to the axis of the said ring, and extending about onehalf around the same. At each end of this flange, at its outer edge, is erected a post, 0, upon which is passed a tubular bearing-sleeve, cl, projecting from the end of the cam-plates G, which thus have free vibration on said posts.

d indicate coil-springs on the sleeve (1, and secured at one end to the flange b, and at the other to the canrplates aforesaid, the object of which will be hereinafter set forth. These cam-plates bear at their free ends upon the flange b, and are widest at this part. Nearer their point of vibration they are cut away, as indicated at e.

D indicates alever-hammerpivoted to apost,

I), on the door, and actuated to strike the hell 1) by means of a spring, S, arranged between the post and the power end of the lever in a tubular box, f. The end of the hammer is provided at its end next the knob with an anti-friction roller, g, that bears against the flange 1), between the free ends of the camplates, when the knob is not in use. The knob being turned, however, the roller ascends the incline of one of the cam-plates and causes the spring S to be compressed. Upon reaching the cut-away point e of said plate it passes ott' therefrom, suddenly releases the hammer, and sounds the alarm violently. The knob, being released after opening the door, returns to its normal position through the medium ofa suitable spring. During this return movement of the knob the cam-plates are drawn past the anti-friction roller, which, being stationary and bearing against the edge of said plate, causes it to swing upon its pivot and allow the said roller to return to its proper normal position between the ends of the said plates. These latter being released by the roller are swung back and reset by the reaction of the spring (1 in readiness for a subsequent movement of the knob. These plates, at their hearing on the flange, are made thin or wedging.

In practice, when not convenient, the collarring need not be secured to the knob, but may be applied on a supplemental bearing on any part of the door, and may be actuated by suitable connections from the knob.

What I claim as new, and desire to secure by Letters Patent, is-- In a door-alarm, the combination, with a spring-actuated hammer, D, having an antifriotion roller, g, in its power end, and a bell, D", of a ring, I), secured to the door-knob and having the flange I), the inclined cam-plates O, pivoted to posts erected at the ends of said flange and bearing on said flange at their ends, and the coil spring d returning the said plates to their places, substantially as specified.

In testimony that I claim the above I have hereunto subscribed my name in the presence of two witnesses.

MICHAEL TBUBY.

Witnesses:

JOHN TRUBY, HENRY V. (loans.

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