Miners' Cap Lamp

Progress, Volume X, Issue 1, 1 September 1914, Page 31

Miners' Cap Lamp

The electric lighting outfit for miners is intended to take the place of the present oil lamp, which burns with open flame and is carried in the hand or is fastened to the cap, or of the present safety oil lamp the wick of which is enclosed in a tube of wire gauze. The electric outfit consists of the reflector, inside of which a small tungsten lamp is placed, and of the battery, which is connected to the tungsten lamp by means of an insulated double wire. The wire is protected at both ends by steel flexible springs so as to prevent its breaking. The cap lamp is to be fastened to the miner cap just like an ordinary oil lamp, no change of the cap for this purpose being necessary. The battery is carried on the back of the miner on a belt. Care is taken that the miner is not able to open the reflector, unscrew the tungsten lamp and cause a spark, nor to lift the cover from the battery, in which case he would again be in a position to produce sparks by short-circuiting the poles of the battery. For this purpose, the reflector is provided with a flange through which eight holes are drilled, the counter-flange of the ring which holds the lens in place showing one

hole which meets one after the other the eight holes of the flange of the reflector. A steel wire with a lead seal, drawn through the holes, prevents the ring from turning unless the seal is broken. On the other hand the plug, which fits in the cover of the battery container, is mechanically locked inside the cover by a moveable steel rod which is automatically

pushed through a protruding steel tongue of the plug. The latter can be pushed into the cover but cannot be taken out unless the cover is unlocked and lifted. As the miner gets the container in a locked condition, he cannot reach the battery unless he breaks or opens the lock by force. The Edison Battery is intended to feed the tungsten lamp for ten hours after a normal charge, but will give, in case of emergency, current for as long as fifteen hours. Normal discharge rate Amperes ...... 0.45 Total weight of battery in ounces ...... 42.5 No. of cells per lamp ...... .;..., ...... 2. Capacity Ampere hour ; 4.5 Normal charging rate Amperes 1. Length of charge, hour ...... 8, Weight of —ounces . 15. Bated candle power of bulb 7/10 Eefleeted candle-power 3. No. of hours lamp will burn on one charge ..:... . 15.