US2091782A - Lamp focusing device for electric fixtures - Google Patents

Description

Aug. 31, 1937. w, KNAPP 2,091,782

LAMP FOCUSING DEVICE FOR ELECTRIC FIXTURES Filed Feb. 1, 1937 INVENTOR.

W/Y/AQM lfx7 BY ATTO NEY.

Patented Aug. 31, 1937 UNITED STATES PATENT OFFICE LAMP FOCUSING DEVICE FOR ELECTRIC FIXTURES 1 Claim.

This invention relates to electric lamp focusing or controlling devices, and has for one of its objects the provision of a light diffusing bowl or shade-holder which may be readily raised or lowered upon its stem or support relatively to the lamp so as to permit its use in connection with a variety of sizes of lamps.

Another object of the invention is to provide such a holder which is open at the top so as to permit the heat generated by the lamp to be dissipated and thus eliminate a fire hazard by preventing the wiring from becoming overheated as is the case with the closed shade holders now commonly used.

A further object of the invention is the provision of a device of the character described which may be operated without the use of tools, and one in which the use of socket extensions is avoided.

Another object is to produce a device of the character described in which the maximum simplicity of construction and operation is secured. 7 Other objects and advantages will appear as the nature of the improvements is better understood, the invention consisting substantially in the novel arrangement and co-relation of parts herein fully described and illustrated in the accompanying drawing, wherein similar reference characters are used to describe corresponding parts throughout the several views, and then finally pointed out and specifically defined and indicated in the appended claim.

The disclosure made the basis of exemplifying the present inventive concept suggests a practical embodiment thereof, but the invention is not be restricted to the exact details of this disclosure, and the latter, therefore, is to be understood from an illustrative, rather than a restrictive standpoint.

The inventive idea involved is capable of re- 40 ceiving a variety of mechanical expressions, one

of which, for the purpose of illustration, is shown in the accompanying drawing, in which- Figure 1 is a view in side elevation of an electric lighting fixture showing my improved holder as 45 applied thereto;

Figure 2 is a sectional view at an enlarged scale of my improved holder and the clamping means therefor;

Figure 3 is a top plan view thereof looking from 50 the top of Fig. 2;

55 and Fig. 7 is a top plan view thereof.

Referring now to the drawing in detail I0 indicates an electric lighting fixture, comprising a tube or stem I I through which passes the electric wiring I2 which is suitably connected to the electric socket I3 which in turn is secured to the lower end of the stem I I by means of a set screw I4.

Mounted on the stem or pipe I I is a bushing I5 provided at its lower end with an enlarged portion or boss I Ii having a plurality of threaded holes or openings II. The upper portion of the bushing I5 comprises a reduced cylindrical screw threaded portion I8 tapered and unthreaded at its free end I9 and has cross slots which extend approximately to the top of the enlarged portion I6. A nut 2|, having a threaded opening 22 terminating in an unthreaded tapered portion 23, provides means for clamping the bushing I5 to the stem II in desired position.

A cylindrical shell or holder 24 open at both ends and made of any suitable material such as for instance metal, glass, etc. is secured to the bushing I5 by means of screws 25 which pass through the said shell and are threaded into the threaded openings I! in the boss I6. The holder 24 is provided near the bottom thereof with a plurality of anchoring openings 26 in which chains or other suspension means 21 may be anchored for supporting a reflector or light difiusing bowl 28. g

In Fig. 2 of the drawing I have shown an electric bulb 30 provided with a substantially long neck 3I used in connection with my device. In order that I may employ a small lamp with a much shorter neck the nut 2| is slightly loosened and. the holder may be moved up to the dot and dash position shown in said Fig. 2 or to any other desirable position, the nut may then be tightened again and a smaller lamp inserted into the socket I3. It will also be seen that due to the opening 32 at the top of the holder 24 any heat generated by the lamp 30 will be dissipated therethrough and the wiring I2 will be prevented from becoming overheated, thus eliminating the possibility of short circuiting or break-down of the wire insulation.

From the foregoing it will be seen that I have provided a simple and efiicient means for adjustably securing a globe or light diffusing bowl holder to a support or stem, so that the said globe or holder may be moved up or down with respect to the electric light bulb for properly focusing the light, and to dissipate any excess heat generated by the lamp.

Having described my invention, What I claim as new and desire to secure by Letters Patent is:

A holder for securing a light difiusing device to a fixture stem, comprising a holder shell open at the top and bottom and provided with radially spaced apart openings near the top thereof, a bushing having a central bore for the reception of the stem, a boss on the bushing having radially spaced apart threaded openings, screws passing through the threaded openings in the holder shell and boss, and exteriorly threaded longitudinally split shank on the bushing above the boss, a tapered unthreaded end on the shank, and a nut having a threaded opening terminating in a tapered unthreaded portion for releasably clamping the bushing to the stem.

WILLIAM KNAPP.

Images