Patent ID: 8342570

Claim:
An air bag system for a vehicle comprising an air bag body formed by stitching base fabric material, an inflator that charges the air bag body with gas, and a vent hole that is a through hole provided in the air bag body so as to communicate the inside with the outside of the air bag body, wherein the vent hole of the air bag body is formed to be slit-like and longer in a longitudinal direction thereof, and the air bag body comprises: two base fabric pieces joined together at a joining seam that is spaced apart from outer perimeter edges of the base fabric pieces such that overlapping side ends are disposed between the outer perimeter edges and the joining seam; and a tensile-force applying mechanism that applies tensile-force in the longitudinal direction of the vent hole, including a pair of V-shaped stitched lines formed on the side ends of the two base fabric pieces with a predetermined distance therebetween such that the V-shaped stitched lines define the vent hole as an unstitched slit formed by a discontinuity in the joining seam; wherein the side ends of the base fabric pieces are disposed in the interior of the airbag body; wherein at least one segment of each of the V-shaped stitched lines extends into the airbag body; and wherein portions of the side ends disposed between the pair of V-shaped stitched lines define a pair of faces and form a flow-passage restriction membrane.