US474906A - Keyhole-guard - Google Patents

Description

(No Model.) v

O. L. GOODRIDGE.

KBYHOLE GUARD.

No. 474,906. Patented May 17,1892.

Invert/1307:

Witnesses UNTTED STATES FATENT @rrrcn.

CHARLES L. GOODRIDGE, OF PORTLAND, MAINE.

KEYHOLE-GUARD.

SPECIFICATION forming part of Letters Patent No. 474,906, dated May 17, 1892.

Application filed October 5, 1891. Serial No. 407,761. (No model.)

To all whom it may concern:

Be it known that I, CHARLES L. GOODRIDGE, a citizen of the United States, residing at- Portland, in the county of Cumberland and State of Maine, haveinvented certain new and useful Improvements in Devices for Closing or Locking Keyholes; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

My invention relates to that class of keyhole-guards wherein a sliding plate is used to cover the keyhole, said plate being operated by the key when inserted from the side of the lock opposite to that where the sliding plate is mounted. In these keyhole-guards it is desirable to provide a support for the inner end of the key and to prevent the ward of the key from interfering with the operation of the plate. In my device I mount the sliding plate on the inner surface of the lock, and around the inside of the keyhole I place a boss, which forms a guide for the sliding plate and which also forms a bearing for the spindle of the key and offsets the ward of the key in such a way that it cannot interfere with the slide.

In the accompanying drawings I have illustrated a lock to which my invention has been applied.

In the drawings, Figure 1 represents myattachment in elevation on the inside of a plate of the lock, one side of thelock being removed. Fig. 2 is a transverse section on line y y of Fig. i. Fig. 3 isa transverse section, the same as Fig. 2, showing my attachment on both sides of a lock; and Fig. 4 is a view of the end of the key.

A represents the casin g of a tumbler-lock of any ordinary construction. The two sides of the look I shall hereinafterterm the plates of the lock.

B represents the main bolt of the lock,and C is the key. The key 0 has a ward which contains on the edge next the end of the key a projection 0, extending out from the end of the ward. The opposite edge 0', I prefer to make plain, for the'reasons hereinafter shown. A sliding plate D is arranged to slide longitudinally, so that it may cover the keyhole a. I here show the plate D as held in guides against the inside of the plate of the lock andarranged so that it may slide to bring its inner end across the keyhole. The lower edge of the plate D is held -by a flange d and the upper edge by a boss E, which is secured on the inner surface of the plate of the lock and surrounds the keyhole. The lower portion of the boss is offset, leaving a space in which the end of the plate D slides. The particular-use of this boss will appear later on in the description.

Directly above the boss E is a sliding bolt F and tumbler G, similar in construction, as here shown, to the locking bolt and tumbler of an ordinary tumbler-lock. The tumbler is operated by a spring II in the usual way.

I make no claim on the particular form of bolt and tumbler here shown, nor do I wish to limit myself thereto. The bolt F and tumbler G' are constructed so that they will extend out from the plate of the look aless dis tance than the surface of vthe boss. This is done in order that the inner ward of the key will clear them when the key is turned. If the inner edge of the ward is not straight, they must set in sufliciently so that the ward will clear them. The bolt F is pushed back and forth by the projection c on the end of the ward, which follows around the edge of the boss E, as shown in Fig. 2. The plate D is attached to the bolt F and moves back and forth with it.

It will now be clear how my device operates. Assuming that the key is inserted from the inside of the door in Fig. 2, the keyhole-locking device will be outside. The projection c on the key extends down by the edge of the boss, but not sufficiently far to touch the plate D. As the key turns to throw the main bolt forward the projection c on the ward also throws the bolt F forward and slides the plate D over the'keyhole, looking it in place there as the bolt F is locked by the tumbler. The key may now be withdrawn and the outer keyhole will be closed and locked until the door is unlocked from the opposite side, when the plate D will be pushed back in the same manner that it was pushed forward.

In Fig. 3-1 show how my device may be applied to both keyholes of a look. It is necessary to have the inside edge of the ward straight, or so formed that it will swing free from the bolt and tumbler next to the keyhole in which the key is inserted, as is seen in dotted lines in Fig. 3. It will be seen that the boss E has two functionsname1y, on one attached to said bolt for closing the keyhole, and a boss around the inside of said keyhole for offsetting the ward of the key, combined with the key having a projection on its ward for throwing the bolt and lifting the tumbler, substantially as described.

In testimony whereof I affix my signature in 20 presence of two witnesses.

CHARLES L. GOODRIDGE. Witnesses:

S. V. BATEs, B. S. HAYWARD.

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