Patent ID: 8448980

Claim:
An active bolster for protecting a person in a passenger seating area in an automotive vehicle during a crash event, comprising: an expandable back wall for mounting against a rigid structure of the vehicle; an expandable front wall overlying the back wall and forming an interior trim component of the vehicle, wherein the front wall has a generally planar first surface facing the passenger seating area and a second surface facing the back wall, wherein the front wall and back wall have outer peripheral edges sealed together to provide a bladder chamber therebetween, and wherein the unexpanded first surface is skewed with respect to the passenger seating area defining a close quadrant and a distant quadrant on opposite ends of the first surface; and a gas source for supplying an expansion gas to inflate the bladder chamber during the crash event; wherein the back wall has a substantially stationary central mounting section for attaching to the rigid structure and a pleated section between the central mounting section and the peripheral edge, wherein the pleated section comprises a plurality of generally-circumferential pleats that unfold during inflation, wherein the pleats provide a transverse curve length that is radially variable, wherein a smallest transverse curve length in the distant quadrant is greater than a largest transverse curve length in the close quadrant so that the expansion of the bladder chamber is biased toward the distant quadrant.