Patent ID: 7052037

Claim:
An inflator for an air bag, comprising: a cylindrical inflator housing charged with a pressurized medium inside and formed with an opening portion at an axial end portion thereof; a diffuser portion installed at the opening portion of the inflator housing, provided with a gas discharging port, and having an inner space extending from the opening portion to the gas discharging port as a gas flow passage; a rupturable plate provided in the gas flow passage inside the diffuser portion to seal outflow of the pressurized medium; ignition means accommodated inside the diffuser portion and adapted to rupture the rupturable plate upon activation; and a gas discharging duct extending from the gas discharging port and having a distal end branched in opposite two directions, wherein an orifice portion for regulating a gas flow amount is formed in the gas flow passage inside the diffuser portion while distal ends of the branched portions in the gas discharging duct are formed with a plurality of openings, and the plurality of openings provided at the distal end of the branched portion in the gas discharging duct are formed such that the total opening area thereof is larger than the opening area of the orifice portion.