Patent ID: 7793973

Claim:
A side airbag apparatus used in a vehicle, comprising: a single airbag accommodated in a backrest of a seat located in a passenger compartment of the vehicle in a folded state; an inflator, wherein the inflator supplies gas to the airbag, thereby deploying the airbag between a body side portion of the vehicle and the seat, wherein the airbag is configured to include an upper portion, a lower portion, and an intermediate portion provided in the airbag and respectively opposed to a shoulder, a lumbar region and a thorax of an occupant sitting on the seat in a lateral direction of the vehicle when the airbag is deployed, wherein the upper, lower and intermediate portions are configured as structurally separate portions along at least an occupant impact side of the airbag, and have respective deployed thickness dimensions in a horizontal direction between the occupant and the body side portion, wherein a portion of the upper portion that has a maximum deployed thickness is located at a position that corresponds to the shoulder, a portion of the lower portion that has a maximum deployed thickness is located at a position that corresponds to the lumbar region, and the intermediate portion is located at a position that corresponds to the thorax and extends from a front end to a rear end of the airbag, and wherein, over the entire area of the airbag, in a front and rear direction of the vehicle, the deployed thickness of the intermediate portion is less than the maximum deployed thickness of the upper and lower portions.