Control-valve assembly

Claim 1

A CONTROL-VALVE ASSEMBLY COMPRISING A HOUSING FORMED WITH AT LEAST TWO CYLINDRICAL BORES; AT LEAST TWO GENERALLY CYLINDRICAL INTEGRAL SLEEVE RESPECTIVELY RECEIVED IN SAID BORES AND FORMING THEREWITH A RESPECTIVE ANNULAR FLUID PASSAGE SURROUNDING SAID SLEEVES, SAID HOUSING BEING PROVIDED WITH FLUID PORTS COMMUNICATING WITH SAID PASSAGES RESPECTIVELY; A PAIR OF RECIPROCABLE VALVE MEMBERS SLIDABLE RESPECTIVELY WITHIN SAID SLEEVES, SAID VALVE MEMBERS EACH BEING PROVIDED WITH AT LEAST ONE ANNULAR GROOVE RECEIVING A RESPECTIVE FIRST SEALING RING SURROUNDING THE VALVE MEMBER AND PROJECTING OUTWARDLY THEREBEYOND, EACH OF SAID SLEEVE HAVING AT LEAST TWO OPPOSITELY CONVERGING FRUCTOCONICAL ANNULAR SEALING SURFACES ENGAGEABLE WITH THE RESPECTIVE FIRST RINGS IN EXTREME AXIAL POSITIONS OF THE CORRESPONDING VALVE MEMBER FOR CON TROLLING THE FLOW OF FLUID BETWEEN THE PASSAGES OF THE RESPECTIVE SLEEVE, EACH OF SAID SLEEVES BEING FORMED WITH AT LEAST ONE OPENING AXIALLY ADJACENT BEING FORMED WITH AT SURFACE AND COMMUNICATING BETWEEN THE INTERIOR OF EACH SLEEVE AND THE RESPECTIVE PASSAGE, SAID SLEEVES AND VALVE MEMBERS BEING INTERCHANGEABLY DISPOSED IN SAID BORES, EACH OF SAID SLEEVES BEING PROVIDED WITH A PAIR OF OUTWARDLY OPEN AXIALLY SPACED CIRCUMFERENTIAL CHANNELS FLANKING THE RESPECTIVE OPENING; AND A FURTHER SEALING RING IN EACH OF SAID CHANNELS BEARING UPON THE WALL OF THE RESPECTIVE BORE FOR DEFINING SAID PASSAGES, SAID SLEEVES BEING OF AXIALLY STEPPED INTERNAL DIAMETERS, EACH HAVING A RELATIVELY LARGE INTERNAL DIAMETER IN THE REGION OF THE RESPECTIVE OPENINGS AND A RELATIVELY SMALL INTERNAL DIAMETER IN RESPECTIVE REGIONS SEPARATED FROM SAID OPENINGS BY SAID FRUCTOCONICAL SEALING SURFACES, SAID FIRST RINGS HAVING AN EXTERNAL DIAMETER GREATER THAN SAID RELATIVELY SMALL INTERNAL DIAMETER.