GB663957A - Improvements in and relating to lighting fixtures - Google Patents

Abstract

663,957. Ceiling lighting fittings. BRITISH THOMSON-HOUSTON CO., Ltd. May 18, 1949 [May 28, 1948], No. 13274/49. Class 75(iv) A circular tubular lamp 2 is supported by a spider 18 the arms 20 of which have their plane surfaces disposed at rightangles to the lamp envelope whereby the spider serves as a louvre. The spider comprises a central dished plate 19 with a fluted reflecting side wall 21 to which the arms 20 are rigidly secured by brackets 27 spot-welded to the ends of two prongs 25, 26 on each arm, one prong 25 extending through a slot in the fluted wall 21, the other being disposed just outside and projecting above the edge of the wall; flanges 29, 30 on the brackets rest on the wall 21 and may be welded thereto. The spider is clamped to a reflector plate 15 by a nut 34 on a pipe 7 extending downwardly through the centre of a conduit box 3 recessed into the ceiling, the reflector plate in turn being clamped by a nut 16 to a circular ballast casing 9 held on the pipe by a nut 10. A selected number of the arms 20 are lined with organic plastic material of low heat conductivity and preferably only these arms embrace the lamp envelope. The outer ends of the arms 20 have narrow tongues passed through slots in the reflector plate 15 to bear against a raised annular section 32 of a ceiling plate 4 secured to the conduit box 3. A lamp socket 13 and a starter switch 14 are mounted on the ceiling plate and extend through apertures in the reflector; the starter switch also extends through the fluted wall 21. A decorative cap 36 is secured to the lower end of the pipe 7.