| 摘要 |
707,166. Street lighting fittings. GENERAL ELECTRIC CO., Ltd., and FERGUSON, H. M. July 7, 1952 [July 11, 1951], No. 16446/51. Class 75 (4) In a directional street lighting fitting having a horizontally disposed linear light source enclosed by a troughlike bowl which has plane light-transmitting side walls 1 disposed parallel to the axis of the light source with their planes within 30 degrees of the vertical when in use, a refractor panel 2 is located adjacent each side wall 1 by means whereby the panel 2 can occupy any one of a number of positions displaced vertically relative to the light source, with its plane parallel to that of the adjacent side wall, thereby providing for adjustment of the vertical beam angle according to the slope of the road on each side of the fitting. As shown each panel 2 is vertically adjustable in flanged guides 6 secured to the inner face of the adjacent side wall 1 and having a screw bolt 5 to engage in one of a number of holes 7 in the guided edges of the panel 2. Each panel 2 has horizontal refracting prisms 3 and may have additional prisms for controlling light distribution in other than vertical planes. The two panels 2 of a fitting may be mechanically connected so that adjustment of one panel effects an opposite adjustment of the other panel. In alternative arrangements, each panel 2 may be formed with pegs or other formations along its edges to engage holes or mating formations on the end walls of the bowl which may be of synthetic resinous material to allow flexing of the end walls for the changing of panel position. |
