| 摘要 |
631,304. Electric lighting fittings. BRITISH THOMSON - HOUSTON CO., Ltd., LOWSON, J. C., and BELLCHAMBERS, H. K Dec. 16, 1947, No. 33151. '[Class 15(iv)] [Also in Group XXXVIII] An electric lighting fitting 1 illuminating a vertical surface 4, and a horizontal surface 6, as of a switchboard 5, comprises a linear light source 2a, 2b arranged above, behind, and close to the said surfaces so that no direct light flux can fall upon them, a diffusing reflecting surface 10 being arranged to direct a portion of the light source flux in a downward direction through louvres 11a, 11b, 11c, to produce an even distribution of light upon the surfaces 4, 6. Additionally the switchboard 5 is illuminated from the ceiling plane 8, 8<SP>1</SP> and the upper walls 9, 9<SP>1</SP> through a reflector 7 disposed behind the lamps 2a, 2b to reflect light upon those surfaces. To enable the indicator lamps 13 of the switchboard to give a clearly visible signal when switched on, under a high level of board illumination, an angularly set cover 14 (Fig. 2) is provided for each lamp, the cover having a window 15 of translucent diffusing material which efficiently transmits light from an indicator lamp bulb 16 but which has a poor reflecting characteristic with regard to light received from any external source. |
