Fully sealed, pressure operated metering valve

Claim 1

A PRESSURE SIGNAL CONTROLLED METERING VALVE, COMPRISING; (A) A HOUSING MEMBER FORMING FIRST AND SECOND AXIALLY ALIGNED, GENERALLY CYLINDRICAL CAVITIES CONSISTING OF A CONTROL PISTON CAVITY AND A VALVE ELEMENT CAVITY, SAID CAVITIES HAVING THEIR ADJACENT ENDS SEPARATED BY A TRANSVERSE BARRIER WALL FORMING THE INNER END WALLS OF SAID FIRST AND SECOND CAVITIES, SAID BARRIER WALL HAVING A FIRST OPENING EXTENDING THERETHROUGH FORMING A CONNECTOR ROD GUIDE BORE ALIGNED ALONG THE AXIS OF THE CAVITIES, SAID FIRST AND SECOND CAVITIES EACH BEING CLOSED AT THEIR RESPECTIVE OUTER ENDS BY AN END WALL, (B) A CONNECTOR ROD OF PREDETERMINED LENGTH DISPOSED IN SAID CONNECTOR ROD GUIDE BORE IN SLIDING ENGAGEMENT THEREWITH, ONE END OF THE CONNECTOR ROD PROJECTING INTO THE FIRST CAVITY AND THE OTHER END PROJECTING INTO THE SECOND CAVITY, (C) A FIRST CONTROL PRESSURE PORT FORMED IN SAID HOUSING MEMBER FOR RECEIVING A VALVE CONTROL PRESSURE SIGNAL, SAID FIRST PORT OPENING INTO THE LATERAL WALL OF SAID FIRST CAVITY AND COMMUNICATING WITH THE INTERIOR THEREOF AT A ZONE THEREOF ADJACENT ITS OUTER END, (D) A PISTON DISPOSED IN SAID FIRST CAVITY AND IN SLIDING ENGAGEMENT WITH THE LATERAL WALL THEREOF, SAID PISTON HAVING FIRST AND SECOND FACES CONFRONTING THE INNER AND OUTER END WALLS OF THE FIRST CAVITY, RESPECTIVELY, SAID PISTON HAVING AN AXIALLY ALIGNED SPACER ROD PROJECTING FROM ITS SECOND FACE, SAID SPACER ROD HAVING A PREDETERMINED LENGTH TO COOPERATE WITH THE OUTER END WALL OF THE FIRST CAVITY TO DEFINE A PISTON LIMIT POSITION IN WHICH THE PISTON IS AXIALLY CLEAR OF THE FIRST PORT, SAID PISTON HAVING A FIRST BLIND GUIDE HOLE FOR SLIDEABLY RECEIVING THE END OF THE CONNECTOR ROD, (E) SECOND AND THIRD VALVE PORTS FORMED IN SAID HOUSING MEMBER AND OPENING INTO THE LATERAL WALL OF SAID SECOND CAVITY AND COMMUNICATING WITH THE INTERIOR THEREOF, (F) A CYLINDRICAL VALVE ELEMENT DISPOSED IN SAID SECOND CAVITY AND IN SLIDING ENGAGEMENT WITH THE LATERAL WALL THEREOF, SAID VALVE ELEMENT HAVING FIRST AND SECOND ENDS CONFRONTING THE INNER AND OUTER END WALLS OF THE FIRST CAVITY, RESPECTIVELY, SAID VALVE ELEMENT HAVING A SECOND BLIND GUIDE HOLE FOR SLIDEABLY RECEIVING THE END OF THE CONNECTOR ROD, SAID SECOND GUIDE HOLE BEING FORMED IN THE FIRST END OF THE VALVE ELEMENT, THE CONSTRUCTION AND ARRANGEMENT OF THE VALVE ELEMENT AND THE HOUSING MEMBER BEING SUCH THAT THE VALVE ELEMENT HAS A PREDETERMINED AXIAL LIMIT POSITION IN THE DIRECTION TOWARD THE INNER END OF THE SECOND CAVITY IN WHICH IS BLOCKS COMMUNICATION BETWEEN THE SECOND AND THIRD PORTS. (G) A HELICAL COMPRESSION SPRING DISPOSED IN SAID SECOND CHAMBER BETWEEN THE OUTER END WALL AND THE SECOND END OF THE VALVE ELEMENT TO RESILIENTLY BIAS SAME TOWARD SAID LIMIT POSITION.