Patent ID: 8714588

Claim:
A side airbag apparatus comprising: a gas generating source, which supplies inflation gas in response to an impact applied from a side of a seat of a vehicle; and an airbag having an inflatable portion, which is deployed and inflated forward by the inflation gas on a side of an occupant seated in the seat to restrain the occupant, and a partitioning member, which divides the inflatable portion into an upstream section into which the inflation gas is supplied from the gas generating source and a downstream section located in front of and adjacent to the upstream section, wherein the partitioning member includes a valve capable of selectively allowing and restricting flow of the inflation gas from the upstream section to the downstream section, the partitioning member having an opening and a pair of valve body elements, in an initial stage of a gas feeding period during which the inflation gas is supplied, the pair of valve body elements are pushed to remain in contact with each other by the inflation gas fed into the upstream section to restrict the flow of the inflation gas from the upstream section to the downstream section through the opening, in a state in which the upstream section has inflated and restrained the occupant, the pair of valve body elements are separated from each other to allow the flow of the inflation gas through the opening in the partitioning member when the partitioning member is caused to warp by an external force exerted from the occupant as a result of restraining the occupant, and the upstream section has a shoulder-protecting portion, which is deployed and inflated on a side of a region of the occupant including at least a rear end part and a middle part of a shoulder of the occupant, in the initial stage of the gas feeding period, internal pressure by the inflation gas keeps the valve body elements in tight contact with each other over an entire surface area so that the valve body elements together create a self-seating state.