Active bolster with internal tear ribs for a contoured inflation shape

摘要

An active bolster for protecting an occupant during a crash event of a motor vehicle includes a back wall and a front wall forming an inflatable bladder. Frangible tear ribs are provided in a central region to limit expansion so a surrounding region expands by a greater distance toward the occupant prior to tearing of the tear ribs providing a contoured shape during inflation deflecting a portion of an impacting occupant toward the central region. The tear ribs separate after a predetermined amount of inflation to provide a cushion in the central region.