Patent attributes
A gas generated by an inflator is supplied through a branching pipe to first and second air bags, which are deployed from a side of a seat to a space between an inner surface of a side of a vehicle compartment and an occupant. A one-way valve mounted in the branching pipe permits the gas to move from the second air bag to the first air bag and inhibits a back flow of the gas, whereby the internal pressure in the first air bag can be maintained higher than that in the second air bag, to thereby restrain the occupant's waist more strongly than the occupant's breast. Moreover, the gas generated by the single inflator is diverted by the branching pipe and supplied to the two air bags. Therefore, the two air bags can be deployed while minimizing the number of the inflator.