Patent ID: 7198289

Claim:
A head portion protecting air bag apparatus for use with a roof side rail and a vehicle compartment side wall, the apparatus comprising: an inflator that supplies a gas; an air bag housed along the roof side rail that is inflated and deployed in a curtain shape along the vehicle compartment side wall by the gas supplied from the inflator provided outside of the air bag so as to protect a head portion of an occupant, the air bag including a front seat inflating portion, a rear seat inflating portion, a non-expanding portion provided between the front seat inflating portion and the rear seat inflating portion, and a gas passage communicated with one or more inflating chambers of each of the inflating portions; a single gas supply port provided with the air bag so that the single gas supply port opens into the gas passage from upward; and an auxiliary inflating chamber provided with the air bag so that the auxiliary inflating chamber is communicated with the gas passage downward of the gas supply port, and the auxiliary inflating chamber opens toward the gas supply port, gas from the inflator being supplied only to the gas supply port; wherein the gas passage is accommodated in a folded manner, for quickly expanding in a vertical direction when said air bag is inflated, wherein the inflowing gas firstly flows into the auxiliary inflating chamber to be further supplied to the front seat inflating portion and to the rear seat inflating portion via the gas passage.