Patent ID: 7168734

Claim:
An inflator for an air bag, comprising: a tubular inflator housing provided at both end portions thereof with opening portions; diffuser portions mounted at said both end portions and provided with a gas discharging port for discharging pressurized medium flowing out from the opening portions into an air bag; rupturable plates which close either one of the opening portions or the gas discharging port to seal off the pressurized medium inside; and igniters provided to rupture each of the rupturable plates, wherein narrow paths for regulating respective flow amounts of the pressurized medium are provided at said both end portions of the inflator housing, and a first gas flow path sectional area of one of the narrow paths and a second gas flow path sectional area of the other of the narrow paths are different from each other, wherein one of the two diffuser portions mounted at the both end portions of the inflator housing is connected to an air bag or air bag portion existing in the vicinity of an upper lateral part of a passenger, and the other diffuser portion is connected to another air bag or another air bag portion existing in the vicinity of a lower lateral part of the passenger, and the first gas flow path sectional area of the narrow path formed at the diffuser portion connected to the air bag or the air bag portion existing in the vicinity of the upper lateral part of the passenger is formed to be smaller than the second gas flow path sectional area of the narrow path formed at the diffuser portion connected to the air bag or the air bag portion existing in the vicinity of the lower lateral part of the passenger.