Patent ID: 7878538

Claim:
An airbag comprising: an airbag panel having a front panel and a rear panel, a single open-and-close venthole, the venthole being located in the rear panel; first and second hanging straps interconnecting the front and rear panels, the first and second hanging straps extending essentially parallel to one another when the airbag is inflated; a constant-open vent hole in the rear panel adjacent to the open-and-close venthole, the constant-open venthole being smaller than the open-and-close venthole; a tether having a first end and a second end, the first end being connected with the first hanging strap at a location between the front and rear panels, the tether extending from the first hanging strap out of the airbag through the constant-open vent hole so that the second end is located outside of the airbag; and a limiting member for limiting a discharge of a gas from the open-and-close venthole, the limiting member closing the open-and-close venthole when an object does not contact an outer surface of the airbag, and opening the open-and-close venthole so that the gas is discharged outside the airbag from the open-and-close venthole when the object contacts the outer surface of the expanded airbag to retreat the outer surface toward an inside of the airbag during expansion of the airbag panel, wherein the limiting member is configured such that a total amount of the gas discharged from the open-and-close venthole becomes largest when the object contacts a center portion, in a left and right direction, of an occupant-facing surface of the front panel of the expanded airbag, and wherein the limiting member comprises a sector-shaped lid body which is configured to close the open-and-close venthole, the sector-shaped lid body having an angled corner integral with the second end of the tether.