A combined low pressure switch, squib and liquid-fueled gas generator device

摘要

A combined low pressure switch, initiator and gas generator device (122) for a vehicle air bag hybrid inflator (120) includes a hybrid squib (192) in a hermetically sealed chamber (144) defined between two conductive apertured support rings (156, 158) separated by a cylindrical ceramic spacer (160). When external overpressure experienced by the chamber falls below a threshold value electrically conductive diaphragms (146, 148) sealed over the support ring apertures move apart breaking an electrical circuit normally completed by a pressure monitoring resistor (154) extending between the diaphragms (146, 148). A pyrotechnic squib (192) in the chamber ignites liquid fuel and an oxidant in the chamber (144) upon initiation. Some or all of the liquid fuel may be incorporated in a hybrid squib in which a pyrotechnic charge is sealed from a supply of liquid fuel.