Pressure relief for a passenger side air bag

Claim 1

An air bag system for a passenger seat, comprising: a housing having an open face to allow air bag deployment, and a rear wall at a side opposite to the open face; an air bag folded in said housing; a gas generator secured to the rear wall of the housing; first outlets formed in the gas generator to allow gas to flow into said air bag folded in the housing; second outlets formed in said gas generator to allow the gas to flow out of said housing; a passage defined in said housing to provide a communication between said second outlets and an outside of the housing; and relief means situated in the passage for allowing the gas to flow from said gas generator into the outside of the housing through the passage when a pressure of the gas flowing through said second outlets exceeds a predetermined level, said relief means including an O-ring disposed to close the passage, and an engagement portion situated in the passage for preventing outward movement of the O-ring from the housing, said O-ring being disengaged from the engagement portion under the pressure of the gas to open said pressure when the pressure of the gas from the gas generator exceeds the predetermined level.