US154410A - Improvement in key-hole guards - Google Patents

Description

I `.U1\T-Irr.n f STATES PATENT OFFICE.

ELIJAH M ()AT, 0F WATERTOWN, MASSACHUSETTS.

lMPRCVEM-EiNT IN KEY-HOLE GUARDS.

Specification forming part of Letters Patent No. 154,410, dated August 25, 18.7111; application filed June 27, 1874.

To all whom t may concern:

Be it known that I, ELIJAH MoAtr, of Watertown, in the county of Middlesex and State of Massachusetts, have invented( a new and Improved Lock, of which the following is a specification:

In the accompanying drawings, Figure 1 represents a side elevation of my improved lock; Fig. 2, a vertical transverse section of the same on the line c c, Fig. 1 Fig. 3, a side view of the lock, with guard-plates thrown over the key hole around the key;` Fig. 4, a

' detail view of n the main tumbler for working manner that the action of the key carries theguardplates over the key -hole not occupied by the stem, previous to the throwing of the bolt, so as.to prevent effectually the opening of the lock with any other key, and to exclude the introductionof implements for assisting the movement of the bolt, and of an additionally protecting latch-tumbler.

My invention consists of a pivoted springtumbler, connected with double-pivoted guardplates, the bolt and latch-tumbler in such a manner that the throwing of the bolt-is' rendered impossible without a key fitting the parts moving the guard-plate, bolt, and additional guard-tumbler.

In the drawings, A represents the bolt of my improved safety 1ock, which is guided in the usual manner and thrown by a key, B, with slotted bit a, engaging in a recess, a', at the rear part of the same. The bolt A is connected by pins or lugs d, projecting at both sides, with the pivoted main tumbler C swinging at one side, and the additional pivoted latchI-ftumbler D at the opposite side of bolt A. The pins d engage in double T- shaped slots d" ofthe tumblers C and D, both tumblers being acted upon by band-springs C and Dl which serve to throw the tumblers in opposite directions and lock over the stop-pins d of the bolt. The main tumbler C is provided above its Vslot d with a slotted recess, e, which embraces a pin, e', of double guard-plates or wards E, which are pivoted above the bolt and swing at both sides of the same, immediately under the outer side plates-of the lockcase. The guard-plates E are securely braced by lateral bars, and provided with slots fat the points at which they pass over the stem of the key B, when the same is placed into the key-hole. The main tumbler G is also recessed to fit over the stem of the key and provided around this,reccss g with a raised and inclined cam, g, for the purpose of .being acted upon by the spurs or projections g2, formed by recessing the bit of the key back of its slotted portion. The turning of the key causes, first, the catching of the spurs over the cam g1, thereby the carrying down of the main tumblerso as to release the stop-pin d from its slot, and throw the guard plates E around the key-stem, closing the key-holes completely thereby. The bit engages next the bolt-recess, and raises also the latch-tum bler D from the opposite stop pin d, so that the bolt is free to be thrown completely for closing or opening the lock. The spring action on` the main and latch tumbler carries them instantly, on the completion of the boltmovement, back over the stoppins, 4 and throws the guard-plates sidewise from the key-holes, producing thereby the rigid and secure position of the bolt and the opening of the key holes for the key. No key which is not constructed to correspond exactly with the threefold functions it has to perform-viz., the throwing of the main tumbler and guard plates, bolt, and latch-tumbler-can, therefore, succeed in forcing the lock, especially as the closing of the key-holes bythe guard plates, previous to the motions of the other parts, prevents the introduction of any implements or devices for throwing the bolt and releasing the tumblers. The action of the key on the parts of the lock, in either direction, is the same, so that-no intermeddling, feeling, or tampering with the open lock is possible.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. -The combination of pivoted main tumbler C, having slots d and e, with main bolt A, and pivotcd double guard-plates E for of key on raised. cam, and releasing' stlpi completion "of `key -actiohy 'subs'tntially 's for throwing the bolt, substantially as and. for specified.

the purpose set forth. l

2. The combination of pivoted main tumbler ELIJAH MOAT'- G,having spring C', swinging glmrd-plzit'es,E,A Witnesses: l bolt A, and pivoted latch tumbler D, with ROBERT E. MOAT, spring D' for throwing bolt-after closing of ABLEL ABBOTT,

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