In many instances, particularly in mining underground, sudden gas outbursts (of methane, CO2) make it necessary for workers to have recourse to respiratory protection within seconds. Taking for granted that under such circumstances protective helmets are worn too, it is provided to combine a helmet with a protective breathing hood. At standby, the hood is carried in folded state in a closed space formed at a bent-out rim portion of the helmet. The hood is connected to a breathing gas supply. Upon opening the supply, the breathing gas flows into double-walled portions of the hood and causes unfolding or unrolling, i.e. stretching of the hood, thus dropping from the helmet around the user's head downwardly. The breathing gas continues to flow into the interior of the hood.
展开▼
