Patent ID: 7380822

Claim:
An airbag capable of being expanded by gas discharged from a gas generator, comprising: a front panel disposed at an occupant side; a rear panel disposed at a side opposite to the occupant side and having a rear panel opening for the gas generator at a center thereof, the front panel and the rear panel being combined at each of peripheral edge portions thereof; an inner panel partitioning an internal part of the airbag into a first chamber and a second chamber surrounding the first chamber, and having an opening to enable the first chamber to communicate with the second chamber, the inner panel comprising a first inner panel at a front panel side, and a second inner panel at a rear panel side, with a substantially center portion of the first inner panel being combined with the front panel, and each of the first inner panel and the second inner panel comprising overhanging portions respectively overhanging from an outer periphery thereof; and a combination device for combining a peripheral edge portion of the first inner panel with a peripheral edge portion of the second inner panel, the combination device comprising a first combination device for combining each of the peripheral edge portions of the first inner panel and the second inner panel in a low strength combination, and a second combination device for combining each of the overhanging portions of the first inner panel and the second inner panel in a high strength combination, the first combination device being capable of releasing the low strength combination when an internal gas pressure of the first chamber reaches a predetermined pressure.