Patent ID: 7527289

Claim:
A gas generator for an air bag, comprising: a cylinder member having a gas discharge port; an ignition means chamber provided inside the cylinder member and including ignition means; a combustion chamber provided inside the cylinder member and adjacent to the ignition means chamber, and accommodating therein a gas generating agent ignited and burned by the ignition means; and a retainer provided inside the cylinder member and separating the ignition means chamber and the combustion chamber, wherein an inner wall surface of the cylinder member and the retainer defines a gas inflow space, in the combustion chamber, having a width smaller than the gas generating agent, the ignition means chamber and the combustion chamber are in communication only through at least one communication hole, defined by the retainer, that directs the ignition energy into the gas inflow space, the communication hole faces the gas inflow space, and an ignition energy generated by an activation of the ignition means inside the ignition means chamber flows into the gas inflow space via the communication hole, changes its flow direction by colliding against the inner wall surface, and causes the gas generating agent inside the combustion chamber to ignite and burn.