| 摘要 |
1491677 Battery emergency lighting system R B W LOWNDES 16 Oct 1974 [18 July 1973] 34328/73 Heading F4R In an emergency lighting system which is proof against fire and internal explosion and which comprises an electric battery and at least one light unit 14 contained within a cabinet having a transparent cover 10 secured to a housing 12 by a screw thread, the threaded engagement between the cover and housing comprises at least five full threads and there is a gap between the mating threads of 0À002 inch to permit the gradual, and safe, escape of gases to the atmosphere in the event of an internal explosion. The light unit 14 is adjustably mounted on a universal joint 15 and the housing 12 locates a rechargeable battery unit and battery charger. |
