US54383A - Improvement in locks - Google Patents

Description

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UNITED STATES PATENT OFFICE.

W. C. MCGILL, OF CINCINNATI, OHIO.'

IMPROVEMENT IN LOCKS.

Specification forming part of Letters Patent No. 54,383, dated May 1, 1866.

To all whom it may concern:

Beit known that I, W. O. IVIGGILL, of Oincinnati, Hamilton county, and State of Ohio, have invented a new and useful Improvement in Locks, of Vwhich thefollowing is a full and clear description thereof, reference being had to the accompanying drawings, making part of this speciication.-

My invention relates to a simple device, coin posed of a plate and tube, which completely covers the key-hole of the lock when the key is in it, preventing it being opened from the out side.

Figure l represents a perspective view of my improved lock, the back plate being removed, showing the arrangement of the interior parts. Fig. 2 is a transverse vertical sect-ion taken through the key-hole of the lock.

Ais the body of the lock. a is the back plate, which is secured to the body ofthe lock A by screws.

B is the bolt, secured either open or shut by means of lock-bar G, look-barO being operated upon by the key previous to the throwing of bolt B.

Within the lock is the the metal plate D, large enough to cover the key-hole e, over which it is located.

At opposite extremities are springs d, secured to plate D. These springs bear upon the back plate, a, which causes plate D to remain in contact with the lbody of the lock A.

b are guide-pins for plate D, and are secured to the body ofthe lock A.

The plate D is perforated opposite the keyhole e, and a freely-sliding tube, E, inserted.

Operation: In lockingthe door on the inside, the key having been inserted in the keyhole, a slight pressure is sufficient to press plate D against back plate, a, tube E passing out and filling a larger part4 of key-hole e. The bolt is then thrown and the door locked, the key being in the lock. The plate D is retained in contact with the back plate, a, eii'ectually covering key-hole e, and preventing the picking of the lock from the outside.

Having described my invention, the use and operation of its various parts, I make the followingclaims, which I desire to secure by Letters Patentl. The plate D and springs d, operating and constructed as and for the purpose heretofore described.

2. The plate D, springs d, and tube E, conl structed and operating substantially as above described and for the purpose set forth.

W. G. MGGILL. Attest:

A. J. GIBSON, f WM. DOEGEN.

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