Abstract: A test system is provided for simulating pre-tensioner systems that use pyrotechnic gas generators. In a preferred form, the test system includes a pneumatic cylinder energized by pressurized air from an accumulator and passing through a fast acting ball valve. A substantially linear relationship is established between accumulator pressure and the time rate of change of acceleration of a piston in the pneumatic cylinder. Use of the test system allows improved evaluation of seat belt systems employing pre-tensioners with pyrotechnic gas generators.

Abstract: A device (60) for inflating an air bag (36) adapted within a steering wheel comprising: a pressure vessel (66; 166; 210) formed of a length of narrow tubing for storing a quantity of inert gas under pressure and a rupturable disk (80) for enclosing a first end of the tubing; an activator or initiator such as a squib (120) responsive to a control signal indicative of a vehicular crash situation for opening the seal means to permit the pressurized gas to inflate the air bag and a manifold (50) for communicating released gas to an air bag.