Patent ID: 7490854

Claim:
An air bag system comprising: an inflator operable to release inflation fluid; an inflatable air bag, said air bag being inflatable upon release of inflation fluid from said inflator; an air bag housing substantially surrounding said air bag, said housing having a vent for venting inflation fluid released by said inflator; a vent-modifying mechanism operatively connected to said housing, said mechanism comprising: a vent blocker movable from a first position to a second position to adjust inflation fluid flow through said vent; and a retention member operable to retain said vent blocker in said first position; a movable member at least partially defining a pressurizable chamber; and an actuator operable to selectively release actuation fluid into said pressurizable chamber, thereby pressurizing said pressurizable chamber to move said movable member from an undeployed state to a deployed state; and a flexible sensing tether extending between said air bag and said retention member, said sensing tether operable to release said retention member to permit movement of said vent blocker from said first position to said second position.