US51621A - Key-guard for locks - Google Patents

Description

NITED STATES PATENT OFFICE.

J. M. RIX, BOSTON, MASSACHUSETTS.

KEY-GUARD FOR LOCKS.

Specification forming part of Letters Patent No. 51,621, dated December 19, 1865.

To all whom it may concern:

Be it known that I, J. M. RIX, of Boston, in

' the county of Suffolk and State of Massachutaken in the line 00 m, Fig. 3; Fig. 3, an endview of the same.

Similar letters of reference indicate correspondin g. parts.

This invention relates to a new and improved device to prevent locks being illegitimately opened by operating from the outside of the door upon a key inserted in the look at the inner side of the door--a means frequently resorted to by burglars and thieves to effect an entrance into a house or into an apartment thereof.

A represents a bar having at one end of it a face-plate, B, at right angles with an elongation or bar, 0, projecting from it in aline parallel with A. The upper edge of the bar A is notched or toothed to form a rack, a, and the face-plate B has a slot, 12, made in it. (See Figs. 1 and 2.)

D represents a case of rectangular form, which is fitted on the bar A and allowed to slide freely thereon. This case has its sides projecting above the sides of the bar A, and it is open at its top to receive a support, 0. This case D is wide enough to receive a slide, E, at one side of bar A, and at one side of the case there is a pin, (1, which passes into a slot, e, in the slide E and serves asa guide for the same, and admits of the slide E moving a certain distance back and forth.

The outer end of the slide E is provided with a head, f, which, when the slide E is fully shoved into the case D, comes in contact with the end of the case. p

In the upper part of the case D, above the bar A, there is placed a pawl, F, which is held down into the rack a by means of a spring, g, which, besides performing this function, serves as a support for the sides of the case.

At each side of the caseD there is attached, by a pivot, h, a metal strip, G, of T shape. The upper prongs of these strips are of hook shape, as shown at i, the pivot h serving as a center for the strips G to turn upon, and admitting of the prongs 21 being raised and lowered at will. These strips G are connected at the under side of the case D by a narrow strip, j, which, when the strips G are fully raised,

comes in contact with the bottom of D.

The inner end of the slide E .is beveled at its upper edge, and when said slide is fully shoved into the case D it throws the pawl F up free from the rack a, to admit of the barA being moved'in the case D; and asmall pin, k, projects down from the bar A to prevent the case D slipping off from it.

The device is used or applied as follows: Suppose the slide E to be into the case D and the latter pressed forward against the face-plate B, this being the most compact manner in which to carry the device, place the thumb of the right hand upon the hooks i of the strips G, with the forefinger on the under side of the case D, and press the hooks down even with the top of D. The key of the lock is then turned so as to throw its bolt into the socket, or, in other words, the lock is locked, and the bowa of the key will bein a horizontal position, or nearly so. The face-plate B is now hooked upon the shank of the key and the bar or projection O shoved into the keyhole until the-face plate B comes in contact with the door or lock-case. The hooks c i are then raised and the case D drawn back until the hooks "L i slip over the inner side of the bow a of the key. The slide E is then drawn back, and the pawl F falls into the rack a of the bar A, and the key is firmly secured in the lock with its bit b in a horizontal position. The keytherefore cannot be punched or forced out from the lock or turned when in the look by any implement; neither can any one look into the apartment through the keyhole, as the latter is closed, and the key is prevented from being turned in consequence of the hooks M catching over the bow of the key.

In order to release the key, the slide E is shoved into the case D and the pawl F there by raised from the rack a, so that the case D may be shoved forward and thehooks ii moved off from the bow to".

The device may be carried in the pocket without any inconvenience, as it may be constructed in a very compact manner.

Having thus described my invention, I claim as new and desire to secure by Letters Patent The rack-bar A, provided with the face-plate B and projecting bar (Lin connection with the case D, provided with the pawl F and strips G G, with hooks i '5 and the slide E, all arranged to operate in the manner substantially as and for the purpose set forth.

J. M. RIX.

Witnesses J. E. POOR, WM. L. HoDsDoN.

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