Hybrid gas generator for air bag inflatable restraint systems

A hybrid inflator for an air bag comprising,

• a storage chamber for storing inflation gas under high pressure, said storage chamber being formed by a hollow cylindrical sleeve that is closed at one end and open at an opposite end, wherein said hollow cylindrical sleeve is closed at sad one end by a fill plug means,
• a pyrotechnic heater closing said opposite end of said sleeve, said pyrotechnic heater being recessed into said sleeve and including a combustion chamber having a pyrotechnic charge therein, a nozzle orifice, a solid plug means abutting a shoulder adjacent said nozzle orifice, and a first diaphragm,
• wherein said fill plug means is welded in sealing relation to said one end of said sleeve and said pyrotechnic heater is welded to the other end of said sleeve in sealing relation,
• a diffuser having a plurality of orifices for dispensing inflation gas from said storage chamber uniformly into an air bag, and
• a second diaphragm,
• said storage chamber being sealed from said diffuser by said second diaphragm and being further sealed from said combustion chamber by said first diaphragm backed up by said solid plug means against the high pressure of the inflation gas stored in said storage chamber,
• wherein said diffuser includes a cylindrical housing having a first end closed off by a plate that is welded in sealing relation thereto and having a second end welded to a portion of said sleeve intermediate the ends thereof with said second diaphragm positioned between said sleeve and the second end of said diffuser housing,
• whereby as the pressure in the combustion chamber rises and exceeds the pressure of the stored inflation gas in said storage chamber upon ignition of said pyrotechnic charge, said solid plug is unseated with said first diaphragm subsequently rupturing since it s unsupported when the pressure in said combustion chamber exceeds the pressure in the storage chamber, and hot gas from the burning pyrotechnic charge heats the stored inflation gas in said storage chamber causing a rapid pressure rise therein so that when the pressure in said storage chamber excess the structural capability of said second diaphragm rupture of the latter occurs allowing the heated gas to vent through said diffuser orifices into an air bag.

A hybrid inflator for an air bag comprising,

• a storage chamber for storing inflation gas under high pressure, said storage chamber being formed by a hollow cylindrical sleeve that is closed at one end and open at an opposite end,
• a pyrotechnic heater closing said opposite end of said sleeve, said pyrotechnic heater being recessed into said sleeve and including a combustion chamber having a pyrotechnic charge therein, a nozzle orifice, a solid plug means abutting a shoulder adjacent said nozzle orifice, and a first diaphragm,
• a diffuser having a plurality of orifices for dispensing inflation gas from said storage chamber uniformly into an air bag, and
• a second diaphragm,
• said storage chamber being sealed from said diffuser by said second diaphragm and being further sealed from said combustion chamber by said first diaphragm backed up by said solid plug means against the high pressure of the inflation gas stored in said storage chamber,
• wherein said diffuser includes a cylindrical housing that is closed at one end and is so attached in sealing relation, at the other end thereof, to a portion of said sleeve intermediate the ends thereof as to extend from said sleeve at substantially a 90.degree. angle,
• whereby as the pressure in the combustion chamber rises and exceeds the pressure of the stored inflation gas in said storage chamber upon ignition of said pyrotechnic charge, said solid plug is unseated with said first diaphragm subsequently rupturing since it is unsupported when the pressure in said combustion chamber exceeds the pressure in the storage chamber, and hot gas from the burning pyrotechnic charge heats the stored inflation gas in said storage chamber causing a rapid pressure rise therein so that when the pressure in said storage chamber exceeds the structural capability of said second diaphragm rupture of the latter occurs allowing the heated gas to vent through said diffuser orifices into an air bag.