Breathing apparatus with an automatic firing mechanism

Claim 1

The combination with an open-bottom breathing apparatus receptacle provided with a downwardly depending projection near one side thereof and in the immediate proximity of said open bottom, of a chemical canister insertable upwardly into the receptacle, a candle inside the lower part of the canister for producing oxygen when ignited, a firing mechanism housing secured to the bottom of the canister, a primer for igniting the candle projecting down through the bottom of the canister, an opening in the top of the housing exposing the primer, a hammer in the housing having one end connected to the housing on a transverse axis at one side of the primer, a spring urging the free end of the hammer into contact with the primer, said free end being movable away from the primer to a cocked position, a trigger pivotally mounted in the housing on a transverse axis below the hammer and having one end engaging the bottom of the free end of the hammer in its cocked position to hold it cocked, the opposite end of the trigger being positioned to be engaged by said receptacle projection when the canister is moved up into the receptacle, whereby to depress said opposite end of the trigger to disengage it from the hammer so as to release the hammer and thereby ignite the primer.