Cold deployment pyrotechnic inflator for air bag systems

摘要

A passenger air bag inflator using pressurized inert gas upon initial deployment to provide cool gas to the folded air bag. After the bag has started to unfold, the remaining gas is provided by pyrotechnic gas generant. Pyrotechnic gas expands against a piston. The piston compresses the inert gas and forces it to exhaust from the inflator. Upon expulsion of the inert gas, the piston then becomes a filter for the pyrotechnic. The system provides a reduction in air bag stresses from fast hot gas deployments.