Pressure vent for air bag cushion

Abstract

An air bag cushion having improved frangible vent coverings. The cushion includes one or more vent openings which will permit the inflation gas to exit the cushion and provide the proper pressure reduction for preventing injury to the passenger. Each of the vent openings includes a frangible covering associated therewith. The coverings include a main body have a peripheral shape and size to extend beyond the edge of the vent opening. the main body overlies and completely covers the vent opening. The periphery of the covering is frangibly secured to the cushion, such as by a tear seam. The covering also includes a tab extending outward from the main body, and also overlying the cushion. The tab is permanently secured to the cushion, such as by a permanent seam. The tear seam is designed to release when the pressure in the cushion, acting upon the portion of the covering overlying the vent, exceeds a predetermined pressure which is known to be associated with compression of the cushion by the passenger. When the tear seam fails, the vent is uncovered, and the desired venting occurs. The covering, however is retained to the cushion by the tab and permanent seam.