Self-centering butterfly valve

Claim 1

A BUTTERFLY VALVE COMPRISING A DISC-LIKE BUTTERFLY MEMBER, A SEALING MEMBER ATTACHED ADJACENT TO THE PERIPHERY OF SAID MEMBER, A VALVE BODY SURROUNDING SAID MEMBER HAVING A LONGITUDINAL AXIS, MEANS FOR PIVOTALLY MOUNTING SAID BUTTERFLY MEMBER WITHIN SAID VALVE BODY INCLUDING A PIVOT PIN ATTACHED TO SAID BUTTERFLY MEMBER EXTENDING GENERALLY PERPENDICULAR TO SAID AXIS, A MOUNTING ARM EXTENDING GENERALLY PERPENDICULAR TO SAID PIN HAVING ONE END RECEIVING SAID PIN FOR ROTATION OF SAID PIN THEREIN, A MOUNTING STUD ATTACHED TO THE OPPOSITE END OF SAID ARM, SAID STUD BEING RIGIDLY AFFIXED TO SAID VALVE BODY, A VALVE SEAT FORMED IN SAID BODY ADAPTED TO ENGAGE THE SEALING MEMBER WHEN SAID BUTTERFLY VALVE IS IN A POSITION TRANSVERSE TO THE LONGITUDINAL AXIS OF THE VALVE BODY, THE CONNECTION OF THE PIVOT PIN AND MOUNTING ARM BEING SUCH TO PERMIT THE BUTTERFLY MEMBER TO BE MOVED BY THE PRESSURE OF A FLUID PASSING THROUGH THE VALVE BODY BETWEEN SAID BODY AND PERIPHERAL EDGE PORTIONS OF THE BUTTERFLY MEMBER TO REDUCE CLEARANCE BETWEEN THE PERIPHERY OF THE SEALING MEMBER AND THE VALVE SEAT, AND ACTUATING MEANS FOR CONTACTING AND ROTATING SAID BUTTERFLY MEMBER TO OPEN OR CLOSE POSITIONS RESPECTIVE OF FLUID FLOW THROUGH THE VALVE BODY.