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Publication numberUS602561 A
Publication typeGrant
Publication dateApr 19, 1898
Filing dateNov 2, 1897
Publication numberUS 602561 A, US 602561A, US-A-602561, US602561 A, US602561A
InventorsBoardman J. Loomis
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Boardman j
US 602561 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

(No Model.)

'B. LOOMISQ KEY. N0. 602,561. Patented Apr. 19,1898.



SPECIFICATION forming part Of Letters Patent No. 602,561, dated April 19, 1898.

Application filed November 2, 1897. Serial No. 657,181. (No niodel.)

To all whom, it may concern.-

Be it known that I, BOARDMAN'J. Looms, a citizen of the United States, residing in the city and county of Los Angeles, State of California, have invented a new and useful Improvement in Safety DoorKeys, of which the following is a specification.

My invention relates to keys for door-locks.

The objects of my invention are to provide a key which, when inserted in the lock and the lock locked, can be so manipulated by the person inserting it, who is on the inside, by dividing the web thereof, and turning one half up and the other half down,so that the key cannot be removed from the lock, or the lock unlocked, until it is returned to its normal position, rendering it impossible for one on the outside to tamper with the lock or unlock the door. I accomplish these objects by mechanism illustrated in the accompanying drawings, in which- Figure 1 is a plan view of a key embodying my invention. Fig. 2 is a sectional view of the same, showing the web of the key divided, one-half above and one-half below, in which position it will be placed when it is desired to prevent the doorfrom being unlocked or the key removed from the look from the opposite or out side.

A is the thumb-piece.

Bis the shank of the key, and E is that part of web integral with the stem B. H is a sleeve surrounding the stem or shank B, and D is the other half of the web, which is integral with the sleeve H.

F is a cylindrical projection on the thumbpiece A.

J is a spiral spring housed within the cylindrical projection F and is coiled around the stem B and presses against the sleeve H.

L is a screw which holds in place the shank B on the thumb-piece A.

72. is a catch or projection on the sleeve H, adapted to enter a recess in on the end of the stem. This catch is preferably made square at the end. A like catch is provided on the other side of this sleeve, and a like recess is made on the opposite side of the stem.

The operation of myimproved key is as follows: The normal position of the key is as shown in Fig. 1, in which position it is inserted in the lock, and the lock is then looked. Then the sleeve 11 is pressed outwardly from the web, dividing the web into two parts, and at the same time the catches h h have passed out of the recesses 17 Z) on the stem, permitting the sleeve to rotate on the stem. The sleeve is then rotated on e-half way around and released from the pressure. The impact of the spring will cause the notches to enter the recesses on the stem, (the catches changing places in the recesses,) and that part D of the web will assume the position shown in Fig. 2. The key is now fast in the lock, and the lock cannot be unlocked until the key is placed in its normal position. It can only be removed by one who is on the inside and can get at the key and put the key in its normal position again, after which the lock can be unlocked and the key removed.

I am aware that it is not new to provide a key having a divided web, one part of the web being integral with a sleeve surrounding a stem and the other part integral with the stem and the two parts of the web held into engagement with each other by means of a spring encircling the stem and bearing against the sleeve surrounding the same, and I do not claim the same; but

lVha-t I do claim is In a key, the stem, B, having web, E, projecting therefrom and being integral there-

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5109685 *Apr 15, 1991May 5, 1992Pundra Industries LimitedControl key for extension adapter
US6196036 *Aug 10, 1999Mar 6, 2001Lucent Technologies Inc.Torque-limited key
Cooperative ClassificationE05B19/04