GB370873A - Improvements in or relating to incandescent lamps - Google Patents

Abstract

370,873. Automatic cut-outs for electric lamps. SIEMENS-SCHUCKERTWERKE AKT.-GES., Siemensstadt, Berlin. Oct. 8, 1930, No. 30142. Convention date, Dec. 18, 1929. Void [Published under Sect. 91 of the Acts]. [Classes 39 (ii) and 75 (iv).] In an incandescent electric lamp protected against firedamp by means of a switch which automatically cuts off the current when the lamp is damaged, the bulb, or a glass shade surrounding it, is movably mounted and any movement resulting from an external force is utilized for operating the switch. In the form shown a switch 2 is arranged within a metal body 1 which is closed by a plate 3 carrying an outer glass shade 4 and a removable member 5 which carries a part 6 of a ball-and-socket joint, the other part 7, 8 being formed integrally with a plate 9 which carries an inner glass shade 12 and the holder 10 of the bulb 11. The switch carries a spring-pressed bridge 13 passing through a cover 16 on the member 5, a spring is arranged between the cover 16 and an abutment 17, and between the latter and a second abutment 15 on the ball-and-socket joint is arranged a breakable rod 18. The switch 2 may cut off the current directly or it may short-circuit the current and cause the melting of a suitably located fuse, and the operation of the switch may be controlled by means of a catch which is adapted to be withdrawn by the movement of the bulb or of the glass shade. The outer shade, or both shades, may be movably mounted, and the bulb may be immovable.