US511592A - Keyhole-guard - Google Patents

Description

(No Model.)

0. J.D'A-'VIDSON. KEYHOLE GUARD.

No. 511,592. Patented Dec. 26, 1893' v INVENTOH WITNESSES:

- ATTORNEYS.

ml unouu. umoeummq COMPANY. vuunmarou. n.

" NITED STATES PATENT OFFICE.

OSCAR J. DAVIDSON, OF KINGSBURG, CALIFORNIA.

KEYHOLE-GUARD.

SPECIFICATION forming part of Letters Patent No. 511,592, dated December 26, 1893.

V Application filed Pelmiary 25, 1893 Serial No. 463,670. (lll'o model.)

hole guard which is simple and durable in.

construction, and arranged to close the keyhole whenever the bolt is shot out.

The invention consists of certain parts and details, and combinations of the same, as will be hereinafter described and then pointed out in the claims.

Reference is to be had to the accompanying drawings, forming a part of this specification, in which similar letters of reference indicate corresponding parts in all the figures.

Figure l is a sectional side elevation of the improvement as applied on an ordinarydoor lock, the section being taken on the line 11 of Fig. 3. Fig. 2 is a front view of the same. Fig. 3 is a sectional plan view of the same on the line 33 of Fig. 1. Fig.4 is a transverse section of the same on the line 4-4 of Fig. 1; and Fig. 5 is a perspective View of the same.

The look A, on which the improvement is applied, is provided with the usual casing B, containing the bolt 0, adapted to be shot out or moved in, in the usual manner, by the key D inserted into thelock casing through either of the keyholes in the back plate B, or the cover B of the casing B. In the back plate B and cover B are arranged longitudinallyextending guideways B and B respectively, in which are fitted toslide longitudinally, the keyhole plates E and E respectively each provided with a keyhole E adapted to register with the corresponding keyhole in the respective back plate B or cover B The keyhole plates E and E are provided with forwardly-extending spring extensions E and E respectively, each curved inwardly to engage opposite sides of the bolt 0, the extensions being provided near their free ends on top with notches E and E adapted to be engaged by lugs O and C respectively, projecting from opposite sides of the bolt 0.

In order to hold either or both of the two extensions E or E out of contact with the respective side of the bolt C and the correspondinglug O or 0 ,1 provide a cam F secured on a longitudinally-extending rod G mounted to turn at its inner end in a bearing I-I secured to the casing B, the outer end of the said rod being journaledin thefront plate B of the lock casingB. On the front end of therod G is arranged a handle G for convenientlyturning the rod G so as to move the cam F in contact with either or both of the spring extensions E and E to press the same outward out of engagement with the corresponding lug C or C of the bolt 0. The handle end G ofthe rod G is arranged in a recess B formed in the front plate of the door lock casing so as to present no obstruction on the said front plate B When the handle Gis in the position as shown in the drawings, then the cam F presses the extension E to hold the notch E thereof out of engagement with the lug O of the bolt C. The other spring extension E is disengaged by the can] F and has its notch E in engagement with the lug O, as will be readily .understood by reference to Fig. 3. In this case, the keyhole plate E is inactive and its keyhole registers with the keyhole in the cover B while the other keyhole plate E is active whenever the bolt (He shot out or in, as the extension E of the said plate E is engaged by the lug O.

Now, it will be seen that'when the bolt 0 is in an innermost position, the keyhole E of the guard plate E registers with the keyhole in the back plate B, and when the key D is inserted through the keyhole in the cover B and the bolt 0 is shot out by the key D, then the guard plate E moves withthe bolt 0, thus moving its keyhole E out of register with the keyhole in the back plate B, thus closing the latter and preventing the insertion of a key from that side of the lock. When the bolt 0 is moved inward by the keyD, then the guard plate E moves with it, to again bring its aperture E to register with the keyhole in the back plate B. Now, when it is desired to close the keyhole in the cover plate B then the operator turns the handle G into the position shown in dotted lines in Fig. 2, whereby the rod G is turned, and the cam F moves out of contact with the spring extension E and in contact with the spring exten sion E thus pressing the latter out of engagement with the bolt 0, and permitting the other extension E to engage with its notch E, the lug O of the bolt. WVhen the key D is inserted through the keyhole in the back plate B to move the bolt 0 outward, then the guard plate E moves with the bolt, thus closing the keyhole in the cover B Thus, it will pering with the handle when the door is closed. Having thus fully described my invention,

I claimas new and desire to secure by Letters Patent-- 1. A key holeguard, comprising two plates fitted to slide in the lock and engaging oppositesides of the bolt so as to be moved thereby, and means for disengaging one or both of the plates from the bolt, substantially as described.

2. A keyhole guard comprising a guard plate fitted to slide in the door lock casing and provided with a spring extension adapted to be engaged by the lock bolt and means for The recess B is preferably a half circle having the edges of the front plate full so that there can be no possible tam-.

disengaging the spring extension from the bolt, substantially as shown and described.

3. In a keyhole guard, the combination with a lock having its bolt provided with projecting lugs, of plates fitted to slide in the lock case and each having a spring extension provided with a notch adapted to engage the lugs of the bolt, and means for disengaging one or both of the plates from the bolt,substantially as described.

at. The combination with a door lock bolt provided with lugs, of keyhole guard plates fitted to slide in the door lock casing and provided with spring extensions having notches adapted to be engaged by the said bolt lugs, and a cam for holding one or'both of the said spring extensions out of contact with theilug, and permitting the other extension to move in engagement with its lug, substantially as shown and described.

5. The combination with a door lock bolt provided with lugs, of keyhole guardplates fitted to slide in the door lock casing and provided with springextensions having notches adapted to be engaged by the said bolt lugs,

a cam for holding one of the said spring extensions out ofcontact with the lug, andpermitting the other extensionto move in engagement with its lug, and a rod mounted to turn in the casing and carryingthe said-cam, substantially as shown and described.

OSCAR J. DAVIDSON. Vitnesses:

F. D. RosENDAM, E. A. DAVIDSON.

Images