GB359323A - Improvements in and relating to indirect lighting luminairs - Google Patents

Abstract

359,323. Overhead lamps. HOLOPHANE, Ltd., Holophane House, Elverton Street, Vincent Square, London.- (Dorey, W. A.; of Holophane Glass Co., Newark, Ohio, U.S.A.) Jan. 14, 1931, No. 1311. [Classes 75 (ii) and 75 (iv).] An overhead lamp for indirect lighting, adapted to be secured to or suspended from a ceiling or carried by a pedestal, consists of a light source, preferably an upright or inverted incandescent electric lamp bulb, surrounded by a transmitting refractor adapted to direct a wide spread of light on to the ceiling, the refractor being surrounded by one or more screens adapted to intercept rays of light emitted below the. horizontal. A reflector is preferably arranged below the light source to reflect light into the refractor. The screens and reflector may be made of metal, or the reflector may be of prismatic glass and the screens of diffusing glass which may be coloured and ornamented. The refractor may be made in one or more parts with the prisms or other refracting means on the inside, the outside, or both the inside and the outside. In the form shown in Figs. 1 and 4, the refractor is made in two. parts 3, 4 having smooth outer surfaces and prismatic inner surfaces, and is held in position between a flange 54 on a cast metal lamp socket cover 52 and a supporting ring 65 by means of thin wire tension members 58 disposed within the refractor. The upper ends of the wires 58 are engaged in inclined holes in the lower edge of the cover 52 whilst their lower ends pass through inwardly extending lugs 66 on the ring 65 and are threaded to receive adjusting nuts 61. The reflector 5 is slotted to pass over the wires 58 and lugs 66 and is offset at 69 to engage slidable supporting clips 70 which are locked in position by thumb nuts 71 on screws 72 passing down through the ring 65. The inwardly-directed portion of the main screen 10 is apertured to pass over the screws 72, and a supplementary screen 11 is supported by straps 75 riveted or otherwise secured to the screen 10. The lower part of the screen 10 is covered by a plate 77 which is mounted on a bolt 76 extending downwardly from the reflector 5. The paths of typical light rays are indicated and are described in detail in the Specification. In the form shown in Fig. 7, the wires 58 are replaced by rods 58b made of straps of flat metal twisted to present their narrow faces towards the light rays. The lower ends of the rods 58b are riveted to the supporting ring whilst their upper ends are formed as hooks 92 adapted to be locked over a bead 95 on the lower end of a lamp socket cover 52b by means of a cylindrical retaining ring 94 screwed on to the cover.