Patent ID: 8720940

Claim:
A side airbag apparatus comprising: a gas generating source, which generates inflation gas in response to an impact applied from a side of a seat of a vehicle; an airbag, which is deployed and inflated forward by the inflation gas on a side of an occupant seated in the seat; and an accommodating portion, which is located in the vicinity of a side of the occupant and accommodates the airbag folded into an accommodation state, wherein the airbag in the accommodation state is formed by folding the airbag deployed but not inflated first by a first folding operation, in which an upper portion of the airbag is folded downward, and subsequently by a second folding operation, in which the airbag is folded rearward from front, the airbag includes an inflatable portion, which is inflated by the inflation gas, and a partitioning member, which divides the inflatable portion into an upstream section, to which inflation gas is supplied, and a downstream section located in front of the upstream section and adjacent to the upstream section, the partitioning member includes a valve for selectively allowing and restricting flow of the inflation gas from the upstream section to the downstream section in accordance with a state in whish the upstream section receives an external force by restraining an occupant or in accordance with an internal pressure of the upstream section, and the upstream section and the downstream section are folded by the first folding operation.