Control valves

Claim 1

A CONTROL VALVE COMPRISING A HOUSING HAVING AN INLET FORMED BY A FIRST PORT AND AN OUTLET FORMED BY A SECOND PORT, A DISPLACEABLE VALVE MEMBER HAVING ONE SIDE WHICH CONSTITUTES A VALVE CONTROL SURFACE, SAID DISPLACEABLE VALVE MEMBER BEING DESIGNED SUFFICIENTLY RIGID TO ENSURE THAT, IN OPERATION OF THE VALVE FOR A GIVEN RANGE OF PRESSURES, SAID VALVE MEMBER DEFORMS AN AMOUNT PROPORTIONAL TO THE PRESSURE DIFFERENTIAL ACROSS THE VALVE MEMBER, THE ENDS OF SAID VALVE MEMBER BEING SEALED RELATIVE TO SAID HOUSING AND MOVEABLE RELATIVE TO SAID HOUSING, SAID VALVE MEMBER BEING MOVEABLE AS A WHOLE, A VALVE PART HAVING A PLURALITY OF FIRST PASSAGEWAYS WHICH PLACE ONE OF SAID PORTS IN COMMUNICATION WITH SAID ONE SIDE OF THE VALVE MEMBER, SAID VALVE PART ALSO HAVING A PLURALITY OF SECOND PASSAGEWAYS WHICH PLACE SAID ONE SIDE OF THE VALVE MEMBER IN COMMUNICATION WITH THE OTHER PORT, EACH FIRST PASSAGEWAY INCLUDING A FIRST OPENING ADJACENT ONE SIDE OF THE VALVE MEMBER AND EACH SECOND PASSAGEWAY INCLUDING A SECOND OPENING ADJACENT SAID ONE SIDE OF THE VALVE MEMBER, THE FIRST OPENINGS BEING AT LEAST PARTLY INTERSPERSED BETWEEN THE SECOND OPENINGS, MEANS TO PRECLUDE FLOW FROM THE INLET TO THE OUTLET EXCEPT THROUGH SAID PASSAGEWAYS, AND MEANS FOR APPLYING A FLUID OF CONTROLLED PRESSURE TO THE OPPOSITE SIDE OF SAID VALVE MEMBER TO CONTROL THE EXTENT OF DISPLACEMENT OF SAID MEMBER FROM SAID PART, THEREBY TO CONTROL FLOW FROM THE INLET TO THE OUTLET VIA THE PASSAGEWAYS AND BETWEEN THE VALVE MEMBER AND SAID PART.