Hybrid (augmented) gas generator

Abstract

A hybrid gas generator includes a chamber for storing inert gas under high pressure, a chamber for storing pyrotechnic material used to heat the stored gas, a diffuser which contains gas orifices for dispensing gas uniformly into an air bag assembly, a thin metal diaphragm to provide a pressure seal between the storage chamber and the diffuser, and a metal disk that is scored with a circular groove to seal the pyrotechnic material from the stored gas. Upon receiving an electrical signal an initiator fires and ignites the pyrotechnic charge. As pressure in the combustion chamber rises and exceeds the pressure in the storage chamber the metal disk that is scored with a circular groove ruptures and allows hot gas and burning pyrotechnic material to heat the gas and cause a rapid pressure rise in the gas storage chamber. When the pressure in the gas storage chamber exceeds the rupture pressure of the thin metal diaphragm between the storage chamber and the diffuser, it ruptures and allows the heated gas to vent through the diffuser orifices into the air bag assembly. Other features include the use of metal stampings for many of the parts instead of machined or forged parts, an end plug made in one piece with the storage chamber which reduces the number of bulkhead welds, a dimpled or pronged orifice plate which prevents the exiting orifice from being plugged, and a perforated diffuser with small holes which prevent fragments from escaping the inflator without the use of screens or meshes.