Abstract: The pyrotechnics in an air cushion inflator are caused to function by the auto ignition device when the device is subjected to a high temperature environment, such as a bonfire, at a temperature of 350.degree. F. (177.degree. C.) in place of in the 650.degree. F. (343.degree. C.) range which would occur if there were no auto ignition device. This enables the use of aluminum for the inflator housing, thereby to minimize weight, the aluminum having sufficient high temperature properties to contain the internal auto ignition pressures at 350.degree. F. (177.degree. C.) but not at 650.degree. F. (343.degree. C.).

Abstract: A gas generator or inflator particularly for the inflation of inflatable protective bags that are used in vehicle safety systems includes first and second aluminum structural components. The first component, a diffuser shell having outlet ports, includes integrally formed concentric cylinders which define chambers containing ignition materials, a solid gas generant composition and filters and provide ports for the passage of generated gases from chamber to chamber and then through the outlet ports. The second component, a base shell, has an attachment flange, includes an initiator, and is provided with three concentric surfaces that mate with the ends of the concentric cylinders of the first component. The three concentric cylinders of the first component are simultaneously joined with the concentric mating surfaces of the second component by a single inertia welding operation.