| 摘要 |
327,033. Davis & Son, Derby, Ltd., J., and Grafton, W. April 22, 1929. Battery lamps.-A device for short-circuiting the filament of the bulb c of a miner's lamp and for blowing a fuse i connected with the circuit thereof when the protecting glass casing b is broken comprises a push-rod a which is fitted at one end into a recess b<1> of the casing and depresses a spring-contact strip d. The central contact h of the bulb is connected through a metal piece o to a metal strip g, which is secured between fibre pieces k and is conected through the fuse i to a battery terminal. The screwed thread of the bulb is connected to the other battery terminal through the holder e. |
