Patent ID: 7938445

Claim:
An airbag module comprising: an inflatable frontal airbag cushion comprising a cushion membrane which defines an interior of the inflatable airbag cushion, wherein the cushion membrane has a front region configured to be directed toward an occupant in a vehicle when the cushion is deployed, wherein the front region has an upper portion and a lower portion, wherein the cushion membrane has a top region above the upper portion of the front region, wherein the cushion membrane has a bottom region below the lower portion of the front region; and a partition that divides the interior of the inflatable airbag cushion into a back chamber and a front chamber; wherein the back chamber is positioned to receive inflation gas directly from an inflator while the front chamber receives inflation gas through the partition from the back chamber; wherein the back chamber is sized to be inflated to a substantially larger volume than the front chamber; wherein the front chamber is at least partially defined by the upper portion of the front region and is positioned such that, when inflated, the front chamber cushions an occupant's head while the back chamber cushions an occupant's chest; at least one closeable safety vent that is initially open to vent gas from the front chamber; and a tether coupled to the closeable safety vent and to the front region of the cushion membrane, wherein the tether has a length that permits the closeable safety vent to remain open when the tether is slack and to be adaptively closed as the tether becomes taut; whereby the front chamber inflates less rapidly than the back chamber for cushioning the head of an occupant in a vehicle with less force than the chest of an occupant is cushioned by the back chamber and the closeable safety vent adaptively vents inflation gas based on the obstruction encountered by the front region to control the inflation of front chamber.