GB193439A - Improvements in, or relating to lamps, searchlights and the like - Google Patents

Abstract

193,439. Smith, J. G. Aug. 30, 1921. Search-lights; vehicle lamps.-In a vehicle head-light, search-light, &c. the rays of light from a source of light 3 and a reflector 2 are intercepted by a coaxial conical reflector 4 and directed on to an annular reflector 9 which reflects them forwardly to produce the beam desired to prevent glare. The reflector 4 is secured to the front glass 5 by a bolt and nut 6, and the annular base of the reflector 9 or the cross-section of the beam passing through the glass 5 is of larger area than the opening of the reflector 2. The sides of the conical and annular reflectors are at an angle of 90‹ to each other and they may be curved slightly. In a modification, one or more annular reflectors similar to the reflector 9 may be inserted between the reflector 4 and that reflector. In a second modification, the position of the reflector 2 is reversed and the base of the reflector 9 is oppositely disposed to that of the reflector 4. In a third modification, Fig. 5, the reflector 4 is formed as the central portion of an annular parabolic reflector, this portion being within a cylindrical surface passing through the foci of the lines generating that reflector, the reflector 9 being constituted by that portion of the reflector without the cylindrical surface. To cut out any rays radiating directly from the light source 3, Fig. 1, a small hood may be fitted on the flanged ring 10 of the glass 5 or a short cylindrical portion may be provided between the reflector 2 and the annular reflector 9. The reflector 4 may be displaceable by means of Bowden wire or like mechanism, and certain portions of the reflectors 4, 9 may not be of truly circular sections to cut out undesirable rays.