Patent ID: 7520530

Claim:
A gas generator for an air bag comprising: a housing having a gas discharge port; a plurality of combustion chambers separated by a partitioning member into a first combustion chamber and a second combustion chamber and each combustion chamber charged with a gas generating agent, provided in the housing; a single ignition device chamber accommodating a single ignition device, provided in the housing, the single ignition device chamber communicating directly with each of the plurality of combustion chambers via communication holes, respectively; a combustion product generated by the activation of the single ignition device, passing through the communication holes, flowing into the respective combustion chambers to ignite and burn the gas generating agent charged into each combustion chamber; the amounts of combustion products flowing through the communication holes into the combustion chambers, respectively, being controlled, at least at the beginning of the activation, such that the amounts may be different from one another; the partitioning member maintaining combustion in the first combustion chamber in a completely partitioned state so that gas discharge is secured to the gas discharge port, and during combustion in the second combustion chamber a gas discharge path is secured from the second combustion chamber to the first combustion chamber to the gas discharge port.