Abstract: A pyrotechnic gas generator for inflating safety cushions in vehicles, including a device for regulating the operating pressure and/or limiting the maximum gas pressure in the generator, comprises a combustion chamber defined in a cup-shaped member having its open end releasably held against a casing part and movable away from the casing part, by the gas pressure in the combustion chamber, to open up an injection orifice of variable through flow area which connects the combustion chamber with a cooling chamber containing solid coolant.

Abstract: A gas generator for generating a large volume of gases at moderate temperature in an extremely short time comprises a central combustion chamber containing a solid pyrotechnic charge and an ignition device therefor. The combustion chamber is laterally surrounded by a cooling chamber with which it communicates by means of apertures. In the cooling chamber combustion gases formed on ignition of the pyrotechnic charge are cooled by contact with at least one solid coolant material. The cooled combustion gases are discharged from the generator through apertures in the side wall of the generator which are disposed symmetrically with respect to the axis of the generator, so that when the combustion gases leave the generator they exert substantially no propulsive force on the generator.