Patent ID: 7954844

Claim:
An air bag device comprising: a gas generator that produces a gas when operated; and an air bag that is expanded when receiving the gas through a gas inlet opening, the air bag being adapted to be mounted on and along a side portion of a passenger room of a motor vehicle when it is flat, wherein the air bag comprises: inside and outside base fabrics that are stitched to constitute an outer bag that is flat when receiving no gas, the outer bag being formed with the gas inlet opening; and inside and outside smaller fabrics that are stitched together to constitute an inner bag that defines a major expandable chamber, the inner bag being in the outer bag with a given space therebetween, wherein the inside smaller fabric is stitched to the inside base fabric to form a plurality of first narrow auxiliary chambers defined between the inside smaller fabric and the inside base fabric, wherein the outside smaller fabric is stitched to the outside base fabric to form a plurality of second narrow auxiliary chambers defined between the outside smaller fabric and the outside base fabric, and wherein the major expandable chamber defines a space extending from a front end of the inner bag to a rear end of the inner bag and between said plurality of first narrow auxiliary chambers and said plurality of second narrow auxiliary chambers.