GB1006017A - Reflecting device and lighting fittings incorporating the same - Google Patents

Abstract

1,006,017. Reflecters for lighting fittings. L'ECLAIRAGE TECHNIQUE. Jan. 17, 1963 [Jan. 17, 1962], No. 2205/63. Heading F4R. A reflecter for exterior lighting fittings comprises in combination a dome 3 of parabolic form in the upper part for redirecting the light from the source into a zone close to the vertical, a principal surface 4 on the lower periphery of the reflecter formed by paraboloids arranged symmetrically of the longitudinal axis of the reflecter for redirecting the light into the most distant zone between the fittings and an intermediate zone 5 connecting the dome and the principal surface. The dome is bounded at the rear by a vertical surface 8, the light source being mounted so that the non light-emissive parts are outside the reflecting surface. The dome 3 intersects the vertical plane in a parabola the axis of which is inclined to the vertical at an angle between 15 degrees and 35 degrees, the surface of the dome being generated by a family of parabolas lying in planes at right angles to the line M-N with their vortices on this parabola and the loci of their focal points on a straight horizontal line D. The principal surface 5 is fined by two paraboloids of revolution symmetrically arranged with respect to the vertical plane, the plane at the upper edge of the principal surface being inclined at between 55 degrees and 80 degrees to the vertical and passing through the centre of the circle which is the projecter of the light source 7 on the plane. The intermediate zones are constituted by two paraboloids symmetrical to the vertical plane and having parameters the values of which are between those of the parabola of the dome and the paraboloids of the principal surface. The axes of these paraboloids make angles between 6 degrees and 15 degrees with the centre line of the street.