Annular sealing ring control valve

Claim 1

A VALVE COMPRISING A BODY DEFINING THE WALL OF A FLUID FLOW PASSAGE, A PLUG HAVING TWO AXIAL FACES SEPARATED BY A PERIPHERAL WALL CORRESPONDING TO THE SAID WALL OF THE FLUID FLOW PASSAGE, SAID PLUG ARRANGED INSIDE SAID FLUID FLOW PASSAGE WITH SAID PERIPHERAL WALL IN SEALING ENGAGEMENT WITH SAID WALL OF THE FLUID FLOW PASSAGE, SAID PLUG FORMED WITH AN ANNULAR FLOW PASSAGE IN ONE OF SAID AXIAL FACES, SAID ANNULAR FLOW PASSAGE DEFINED BY AN OUTER WALL AND BY AN INNER WALL WHOSE SURFACE DIVERGES RADIALLY FROM SAID ONE AXIAL FACE TOWARDS THE OTHER SAID AXIAL FACE SUCH THAT THE CROSS-SECTION OF SAID ANNULAR FLOW PASSAGE DIMINISHES PROGRESSIVELY TO A POINT INTERMEDIATE THE SAID TWO AXIAL FACES WHERE THE SAID INNER WALL JOINS THE SAID OUTER WALL, SAID PLUG FORMED WITH A PORT IN SAID OTHER AXIAL FACE, SAID PORT COMMUNICATING WITH SAID ANNULAR FLOW PASSAGE REMOTE FROM SAID ONE AXIAL FACE, A TORODIAL ANNULAR SEALING RING WHICH IS RESILIENTLY EXPANSIBLE CIRCUMFERENTIALLY AND IS SUPPORTED BY THE SAID INNER WALL, SAID ANNULAR SEALING RING ADAPTED TO ENGAGE SAID INNER WALL IN A POSITION ADJACENT THE SAID ONE AXIAL FACE, THE RADIAL THICKNESS OF THE SAID ANNULAR SEALING RING LESS THAN THE RADIAL SPACING BETWEEN THE SAID INNER WALL AND THE SAID OUTER WALL AT SAID POSITION SO THAT FLUID CAN FLOW IN EITHER DIRECTION BETWEEN THE SAID ANNULAR SEALING RING AND THE SAID OUTER WALL, AND SAID ANNULAR SEALING RING ADAPTED TO MOVE AXIALLY FROM SAID POSITION TOWARDS SAID POINT IN RESPONSE TO A PRESSURE DIFFERENCE GENERATED ON THE AXIAL FACES OF THE SAID ANNULAR SEALING RING WHEN FLUID FLOWS IN THE DIRECTION FROM SAID ANNULAR FLOW PASSAGE THROUGH SAID PORT, WHEREBY SAID ANNULAR SEALING RING WILL MOVE AXIALLY WITH CONSEQUENT CIRCUMFERENTIAL EXPANSION TOWARDS SAID OUTER WALL DUE TO THE INTERACTION BETWEEN SAID INNER WALL AND SAID ANNULAR SEALING RING AND WILL REDUCE THE DISTANCE BETWEEN SAID ANNULAR SEALING RING AND SAID OUTER WALL TO REGULATE THE FLOW OF FLUID IN THE SAISD DIRECTION.