Inflatable gas bag for restraining systems in vehicles

Claim 1

An inflatable gas bag for restraining systems in a vehicle having an interior enclosed by a wall, said wall comprising a jacket portion and two side portions sewn thereto, a gas inlet in said jacket portion, said jacket portion including a lower section extending in a generally flat condition from said gas inlet, a generally straight section extending upwardly from said gas inlet, and an arched section extending from said upwardly extending section to said lower section when said gas bag is in a completely inflated state, a fold only in one of said side portions comprising two superimposed wall portions held together in engagement with each other along a separating line separating the interior of said gas bag from a volume defined by said fold, said superimposed wall portions being held together by a holding means and said holding means being so dimensioned in strength that on reaching a predetermined value of gas bag internal pressure said holding means releases said fold, said wall having an asymmetrical form in the completely inflated state, and said fold being disposed in said one side portion in a position and orientation to control the direction of expansion of said gas bag such that said gas bag tends to be unfolded upon inflation in a first direction centrally towards a vehicle occupant while the internal pressure of said gas bag is below the predetermined value and expanding in a second direction transverse to the first direction when the gas bag internal pressure exceeds the predetermined value and said holding means releases said fold.