US959818A - Locking device for incandescent lamps. - Google Patents

Description

G. J. TIMM &: J. A. BARNHARDT. LOCKING DEVICE FOR INGANDESGENT LAMPS.

APPLIOATION FILED APR. 27, 1909.

959,818. Patented May 31,1910.

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CLARENCE J. TIMIVI AND JAMES A. BARNHARDT, OF DULUTH, MINNESOTA.

LOCKING DEVICE FOR INCANDESCENT LAMPS.

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'11) all whom it may concern:

Be .it known that we, CLARENUE J. Turn and James A. BAKNIIARD'L, citizens of the United States, residin at Duluth, in the county of St. Louis and State of Minnesota, have invented certain new and useful Improvements in Locking Devices for Incandescent Lamps, of which the following is a specification.

This invention comprehends means for preventing the unauthorized and surreptitious removal of incandescent lamp bulbs from their sockets, by the provision of looking means which will be simple in construction and durable, and which will ell'ectually prevent the lamp from being removed eX- cept by breaking the globe.

To this end the invention consists essentially in an incandescent lamp which is provided at its base with a catch, designed, when the base is screwed into the casing or key socket to spring into locking engagement with a keeper formed in the socket, thereby preventing the detachment of the lamp from the socket without first breaking the globe of the lamp. And the invention also consists in certain arrangements and combinations of the parts that we shall hereinafter 1 describe and claim.

For a full understanding of the invention and the merits thereof, reference is to be had to the following description and accompanying drawings, in which;

incandescent lamp embodying the improvements of our inventlon. Fig. 2 1s a hOIlzontal sectional View thereof, on an enlarged scale, being taken approximately on the line 22 of Fig. 1. Fig. 3 is a perspective view of the base end of the lamp. Fig. 4 is a detail perspective view of the spring catch. Fig. 5 is an enlarged fragmentary section of the base of the lamp showing the groove formed therein to receive the spring catch.

Corresponding and like parts are referred to in the following description, and indicated in all the views of the drawings by the same reference characters.

Referring to the drawings, the numeral 1 designates a key socket for an incandescent lamp, and 2 designates the lamp, each of these parts being of any desired design and construction, except as hereinafter noted.

3 designates the base of the lamp 2 which is formed Withthe usual screw threads by Specification of Letters Patent.

Application filed April 27, 1909.

@inner wall of the socket 1.

Patented May 31, 1910.

Serial No. 492,497.

which it may be screwed into the correspondingly threaded inner vall of the socket 1.

The base 3 of the lamp carries a spring catch 4 which is so arranged that it will be held in restrained or retracted position during the operation of screwing the base into the socket, and which will, when the base is fully screwed in and is moved rearwardly in any attempt to detach the lamp, spring into a keeper or opening 5, formed in the The spring catch 4 may be formed in any desired way or he of any desired design and the keeper 5 may be formed in any manner, as we do not wish our invention to be limited in these respects, for various changes in the construction, relative arrangement and proportion or design of the parts may be made, without departing from the scope of the invention as described in the appended claims.

In the present embodiment of the invention, the spring catch 4 is formed of a single piece of spring wire, and it embodies a shank (3, inserted in a longitudinal groove 7 that is formed in the base 3. The catch 4 is formed at one end of the shank 6 with an angularly disposed extremity 8 formed into a hook 9 with an outwardly projecting bill as shown, and in the present instance the keeper 5 is formed by cutting or otherwise making an opening in the metal inner portion of the v i socket, where the threads are formed for en- I lgure 1 1s a sectional side elevation of an i gagement with the threaded base 3. The catch is provided at the other end of the shank G with a coiled portion of loop 10, which partially or completely encircles the lamp at the juncture of the globe with the base, said loop serving as a retaining means for detachably holding the catch in position on the lamp before the same is connected to the socket.

From the foregoing description in connection with the accompanying drawing, it is obvious that upon the screwing of the base 3 into the socket 1, the hook 9 of the catch will finally register with the keeper 5 and spring into locking engagement therewith, should any attempt be made to subsequently unscrew the lamp from its socket.

As the spring catch 4 is preferably only detachably connected tothe lamp, by having its shank 6 seated in the groove 7, for example, it is manifest that a lamp base formed for our invention is not limited to use with the locking device such as We have described, but is applicable for any ordinary lamp socket of the type herein disclosed, the formation of the groove 6 in nowise detracting from the general efiiciency of the device.

Having thus described the invention, What is claimed as new, is:

1. The combination with a lamp socket of the type described, formed in its inner Wall with a keeper, and a lam adapted to work into said socket, of a spring catch having a loop atone end and adapted to encircle the base of the lamp and a hook at its inner end adapted to engage said keeper.

2. The combination with a lamp socket of the type described and formed in its inner wall with a keeper, and a lamp adapted to be worked into said keeper by a rotary movement thereof, a catch having an intermediate portion extending longitudinally of the base of the lamp, and a hook at one end with an outwardly turned bill adapted to engage the keeper.

3. The combination with a lamp socket of the type described, formed in its inner wall with a keeper, of a lamp provided with a base formed with a longitudinal groove, and a spring catch having a shank seated 1n sald groove and a hOOK designed to engage said keeper.

4. The combination with a lamp socket of the type described, formed in its inner wall Wit-l1 a keeper, of a lamp provided with a base formed with a longitudinal groove and a spring catch having a shank seated in said groove, a hook at one end of said shank, designed to engage said keeper, and a loop at the other end of said shank encircling the lamp.

5. The combination with a lamp socket of the type described, formed in its inner wall with a keeper, and a lamp provided with a base. adapted to work into the socket by a rotary movement, of a catch having an intermediate portion extending longitudimilly of the base, a loop at one end adapted to encircle the base, and a hook at the other end with an outturned bill adapted to engage the keeper upon a reverse movement of the lamp and socket.

In testimony whereof we allix our signatures in presence of two witnesses.

, CLARENCE J. TIMM.

JAMES A. BARNHARDT. \Vitnesses:

E. G. KREIDLER, J. C. RIESLAND.

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