An Improved Guard for the Locking Bolts of Miners' Safety Lamps.

摘要

23,086. Best, J. C. Oct. 19. Miners' safety lamps.-A guard for protecting the locking-bolt of a miner's lamp is constructed of a sliding sleeve which allows the electro-magnet that unlocks the lamp to be applied directly to the head of the bolt, thus obviating the disadvantages which arise when the electro-magnet has to act through the guard. As shown in Fig. 1, a spring- controlled bolt 2 is formed with a head 3 which moves in an annular recess 4. The guard 6 is tubular and is formed with a flange 6a at its upper end, upon which bears a spring 7 to keep the guard in contact with the head 3. The spring 7 is kept in place by a ring 8 fixed to the lamp bottom. In a modification, the top of the head 3 normally bears against an iron ring fixed at the top of the recess 4, and this ring offers resistance to the withdrawal of the bolt 2, so that a high-power magnet is required to unlock the lamp.