Patent ID: 7891704

Claim:
A side airbag device, which is provided at a seat back of a seat for a vehicle, comprising: an airbag including a chest-abdomen protection portion operative to inflate so as to protect a chest and an abdomen of an occupant seated in the seat and a waist protection portion operative to inflate so as to protect a waist of the occupant seated; and an inflator operative to supply gas to the airbag for an inflation of the airbag at a vehicle side crash or a vehicle turnover, wherein the chest-abdomen protection portion and the waist protection portion of said airbag are partitioned by a partition portion that extends substantially rearward from a front edge of the airbag so that the chest-abdomen protection portion and the waist protection portion are connected to each other via the partition portion, respective insides of the chest-abdomen protection portion and the waist protection portion are interconnected via an connection area that is formed at a rear portion of the airbag, a gas inlet portion of the airbag, through which the gas supplied from said inflator is supplied, is positioned near a rear end portion of the partition portion so that inflation of the chest-abdomen protection portion and the waist protection portion can be started substantially at the same time, a recess is provided at an upper portion of the chest-abdomen protection portion of the airbag so as to retreat rearward from a front edge portion of the chest-abdomen protection portion, and an upper vent hole and a lower vent hole are provided at the chest-abdomen protection portion of the airbag, the upper vent hole being positioned above said recess, the lower vent hole being positioned below said recess.