GB292167A - - Google Patents

Abstract

292,167. British Thomson-Houston Co., Ltd., (Assignees of Falge, R. N., and Brown, W. C.). June 16, 1927, [Convention date]. Void [Published underSect. 91 of the Acts]. Vehicle lamps.-A vehicle lamp is fitted with two sources of light, one in the focus for distant illumination and one above the focus of the reflector for near illumination, and the upper and lower portions of the reflector, or of the front glass, or of both, are so constructed as to depress the upper and lower portions of the beam, the amount of the depression, which is practically unaffected by the position of the light source, being equal to or greater than, that of the central beam. An electric lamp bulb 13 may have one filament 14 in the focus, and another filament 15 above the focus of a reflector 10 having a parabolic central zone. The upper and lower zones 11, 12 of the reflector may be bent or rotated slightly downwards, as shown in Fig. 5, the front glass 16 may have upper and lower prismatic portions 17, 18, as shown in Fig. 6, or a combination of these, two arrangements may be employed. In any of these arrangements, the front glass may be provided with three sections of laterally-spreading prisms 22, 23, 24, as shown in Fig. 4, the spreading power of the prisms 22. 24 preferably being greater than that of the prisms 23. Alternatively, the lateral spreading may be obtained by suitably modifying the shape of the reflector. A circular or other area 25 at the centre of the front glass may be made opaque, diffusing, or prismatic, so as to prevent the central portion of the reflector projecting stray rays above the main beam.