GB193988A - Improvements in and relating to electric lamp fittings - Google Patents

Abstract

193,988. British Thomson - Houston Co., Ltd., (General Electric Co.). Dec. 6, 1921. Projectors; lens holders special to Lanterns.-A spot-light fitting, such as are used for advertising purposes, or for searchlights, and like projection apparatus, is adapted to be detachably secured to an ordinary standard electric - lamp fitting, and consists of an electric incandescent lamp or lamps, a shade member, a two-part reflecting- chamber mounted within the shade member, and a preferably telescopic member for directing the light on to a desired object. The shade 1 is secured to the bayonetjoint or screw-cap fitting of the lamp-bulb 7, and the reflecting-chamber 2, which is pivotally mounted on the shade and is provided with means 4 for locking it in any desired position, is constructed of two hinged portions 5, 6, which form an approximately spherical chamber enclosing a portion of the lampbulb 7. In the upper portion 5, a clearance hole 5a is provided for the passage of the lamp 7 with an extension 5b to permit of angular adjustment of the chamber 2. A light-emitting aperture 8 is provided in the portion of the reflecting-chamber 2 opposite the hole 5a through which the neck of the bulb passes. Surrounding this aperture 8 is a tube 9 secured to the outer side of the reflectsing-chamber and which may have a diffusing or colour screen 10 secured to its inner end. The outer end of the tube 9 is telescopically secured to a second tube 11, which carries a lens 12 at its outer end, adapted to focus the beam of light and to throw it on any particular spot, the area illuminated being made to vary considerably by telescoping the lens-carrying tube 11 over the tube 9 fixed to the reflecting-chamber 2 so as to vary the distance between the opening 8 and the lens 12. The tubes 9, 11 may be locked in any desired position by a screw 13.