| 摘要 |
474,482. Street lamps. HOLOPHANE, Ltd., and ENGLISH, S. July 31, 1936, No. 21257. [Classes 75 (ii) and 75 (iv)] A street-lighting fitting designed so as to give no indication of its existence or location to aircraft comprises a lantern having a'shallow transparent dish 2 with refracting or diffusing prisms on its sides and base, and a reflector 3 surrounding the light source 1 and arranged to reflect light on to the sides of the dish and an outer opaque shield or reflector 8 giving an absolute cut-off along or below the horizontal plane. The run 9 of the shield should be level with or below the lowest point of the dish 2 which for this reason is made shallow. The interior surface of the sides of the dish may carry diffusing prisms or refracting prisms for directing the light into prefered directions. In order to prevent the illumination of buildings, the outer surface of the dish mav be formed with a group of horizontal refracting prisms on the side facing the road, and with a group of reflecting prisms on the other side. Either the bulb or the dish may be coloured blue. |
