GB672924A - Improvements in luminairs - Google Patents

Abstract

672,924. Lighting fittings. HOLOPHANE, Ltd., ENGLISH, S., and HOLMES, J. G. May 19, 1950 [May 20, 1949], No. 13550/49. Classes 75(ii) and 75(iv) A luminair has an elongated light source 1 arranged between two opposed beamforming trough-shaped reflectors 2, 3, each extending on both sides of the principal planes of the two reflected beams and having an elongated beam-forming refractor 12 or 13 respectively within its angular aperture. The reflectors 2, 3 may be of metal, glass or plastic material shaped parabolic in cross-section and may abut on a chord of truncation which passes through the light source 1, the latter being coincident with the focal lines of the two reflectors. The refractors 12, 13 may be of glass, plastic or other transparent material and formed the same depth as, and positioned equidistant from, the chord of truncation of the reflectors, their section being such as to provide either parallel beams whose axes may be coincident with those of the reflector beams, or non-parallel beams. The reflectors 2, 3, may be arranged to include an angle of 180 degrees, or slightly less than 180 degrees as shown to give downwardly inclined beams. To intercept rays not incident on the reflector or refractor systems, an absorbing or reflecting surface 15 may be provided within the reflector mouth. The reflector openings may be closed by a plain or light-diffusing cover which may be mounted in front of the refractors 12, 13 or may be formed as extensions thereof.