Patent ID: 7883110

Claim:
An airbag, comprising: an open-and-close type vent; and a gas discharge limitation member configured to limit a gas discharged from the vent, the airbag being constructed in such a way that when the airbag is expanded the gas discharge limitation member closes the vent or opens the vent by a small amount when an occupant is not in contact with an occupant-facing surface of the airbag and when the occupant is brought into contact with the occupant-facing surface of the expanded airbag, thereby the occupant-facing surface retreats in an opposite-to-occupant direction, the gas discharge limitation member opening the vent by at least a large amount and discharging the gas from the airbag through the vent, the gas discharge limitation member comprising: at least one invertible portion provided in a surface on a side opposite to the occupant-facing surface of the airbag or a side surface of the airbag when the airbag is expanded and capable of being everted toward the outside of the airbag; an interlocking member for interlocking a moving operation of the occupant-facing surface in an occupant direction and an opposite-to-occupant direction and for interlocking a moving operation of the invertible portion inwardly of the airbag and outwardly of the airbag when the airbag is expanded; and a lid member covering the vent and capable of being pulled by the invertible portion when the invertible portion is everted towards the outside of the airbag, wherein the lid member is constructed to close the vent or open the vent by a small amount until the lid member is pulled by the invertible portion and is constructed to open the vent by at least a large amount by pulling the lid member with the invertible portion, and wherein in a state that an approximately entire invertible portion is everted outside the airbag, a length in an everting direction of the invertible portion is formed to be larger than a moving distance where the lid member moves from a position at which the lid member closes the vent or opens the vent by a small amount to a position at which the lid member opens by at least a large amount.