US Patent 9464559 Passive exhaust valve assembly and forming method

A passive valve assembly for an engine exhaust system includes an exhaust conduit for transferring exhaust gases from the engine and a valve plate that is operably disposed within the exhaust conduit. A pivot rod has an internal section that is coupled with the valve plate, such that the valve plate may pivot between an open position and a closed position. The pivot rod also has an external section that protrudes from the exhaust conduit. A stop feature is disposed at or near an exterior surface of the exhaust conduit in a location arranged to contact the external section of the pivot rod and prevent the valve plate from pivoting beyond one of the open position and the closed position.