Flow-through heat-enhanced hybrid inflator

A heat-enhanced inflator for a vehicle airbag, the inflator comprising:

• A) a housing having a cylindrical sidewall, a first end wall, and an open end;
• B) a generally cylindrical heating cup mounted in the open end of the housing, the heating cup including a cylindrical outer wall closely received in the cylindrical sidewall of the housing, a bottom wall and an inner wall extending from the bottom wall concentric with the outer wall;
• C) a second end wall extending across the open end of the housing between the concentric outer and inner walls of the heating cup, and defining an outlet opening circumscribed by the inner wall of the heating cup;
• D) a rupturable diaphragm sealing the outlet opening defined by the second end wall;
• E) a storage chamber defined by the cylindrical sidewall and end wall of the housing and the bottom wall of the heating cup;
• F) an outlet plenum defined by the bottom and inner wall of the heating cup and by the rupturable diaphragm;
• G) an annular heating chamber defined between the inner and outer sidewalls of the heating cup, the bottom wall of the heating cup defining a plurality of inlet openings to the heating chamber and the inner wall of the heating cup defining a plurality of exit orifices from the heating chamber to the outlet plenum;
• H) a diffuser secured to the inflator housing over the outlet opening, the diffuser defining a plurality of outlet ports;
• I) a gas delivery passage extending from the gas storage chamber through the inlet openings to the annular booster chamber, through the heating chamber and the exit orifices therefrom to the outlet plenum, from the outlet plenum through the outlet opening to the diffuser, and out the outlet ports of the diffuser, the gas delivery passage blocked by the rupturable diaphragm until operation of the inflator;
• J) heat-producing material in the portion of the gas delivery chamber formed by the annular heating chamber;
• K) an inert gas stored under pressure within the storage chamber of the cylindrical housing, the annular booster chamber and the outlet plenum, the gas sealed therein by the rupturable diaphragm until operation of the inflator;
• and
• L) means for initiating heat production by the heat-producing material;
• wherein after initiation of the heat-producing material, the diaphragm ruptures to permit an initial flow of inflation gasses from the outlet plenum and a flow of inflation gasses along the gas delivery passage, the gasses being heated and expanded by the heat-producing material in the annular heating chamber.

A heat-enhanced inflator for a vehicle airbag, the inflator comprising:

• A) a housing;
• B) a heating cup mounted to the housing, the housing and heating cup together defining a storage chamber containing compressed inflation gas;
• C) the heating cup defining an outlet orifice from the gas storage chamber covered by a rupturable diaphragm and the heating cup containing an essentially non gas-producing heating composition positioned in a gas delivery passage of stored gas through the heating cup;
• and
• D) initiator means including a squib and a pyrotechnic material, the initiator adapted to apply the pyrotechnic material, upon ignition thereof by the squib, to the heating composition for initiating a heat-producing reaction thereof;
• wherein, after operation of the squib, the diaphragm ruptures to permit a flow of inflation gas through the heating cup and the reacting heating composition therein, and the gas delivery passage and heating cup are configured to permit the heating composition to react to depletion, thereby delivering heat-expanded inflation gas for inflating the vehicle airbag.