Patent ID: 7600777

Claim:
A side airbag apparatus comprising: a gas generator; an airbag that is deployed and inflated in a space between a body side portion of a vehicle and an occupant seated on a seat in a passenger compartment by the pressure of gas injected from the as generator, the airbag having a thickness along a lateral direction of the vehicle when deployed and inflated; an expansion promoting mechanism provided in the airbag, wherein, when the airbag is deployed and inflated, the expansion promoting mechanism promotes the expansion of the thickness of the airbag, wherein the expansion promoting mechanism includes a belt-like tether that is located between opposite inner ends of the airbag and extends in a direction intersecting the lateral direction of the vehicle; an occupant size detector detecting the size of the occupant; and a promotion canceling mechanism that cancels the expansion promoting function of the expansion promoting mechanism when the size of the occupant detected by the occupant size detector is equal to or smaller than a reference size that is determined in advance such that, if the airbag is deployed and inflated, the thickness of the airbag when the size of the occupant is equal to or smaller than the reference size is less than the thickness when the size of the occupant is greater than the reference size.