Two-stage, two-fluid, uni-directional control valve

Claim 1

A UNI-DIRECTIONAL FLOW CONTROL VALVE, COMPRISING A VALVE BODY HAVING AN ELONGATED BORE THEREIN, SAID BORE INCLUDING, IN AXIALLY ALIGNED RELATIONSHIP, A PAIR OF CYLINDRICAL, SPACED CONTROL CHAMBERS CLOSED AT THEIR RESPECTIVE OUTER ENDS, AN INLET CHAMBER POSITIONED BETWEEN SAID PAIR OF CONTROL CHAMBERS AND IMMEDIATELY ADJACENT ONE THEREOF, AN OUTLET CHAMBER ALSO POSITIONED BETWEEN SAID PAIR OF CONTROL CHAMBERS AND IMMEDIATELY ADJACENT THE OTHER THEREOF, AND A CYLINDRICAL VALVE SEAT HAVING A DIAMETER SMALLER THAN THOSE OF SAID INLET AND OUTLET CHAMBERS AND EXTENDING THEREBETWEEN, SAID INLET AND OUTLET CHAMBERS BEING IN COMMUNICATION WITH THE EXTERIOR OF SAID BODY, A SPOOL AXIALLY SHIFTABLE WITHIN SAID BORE AND HAVING A LENGTH LESS THAN THE LENGTH OF SAID BORE BUT GREATER THAN THE DISTANCE BETWEEN SAID CONTROL CHAMBERS, SAID SPOOL INCLUDING A PAIR OF SPACED CONTROL SECTIONS EACH OF A UNIFORM DIAMETER THROUGHOUT, EACH CONTROL SECTION BEING IN SEALED ENGAGEMENT WITH THE WALL OF ONE OF SAID CONTROL CHAMBERS, A PRESSURIZED FLUID IN SAID CONTROL CHAMBERS AND ACTIVATING SAID CONTROL SECTIONS, A CYLINDRICAL VALVE CORE SECTION IN SEALED ENGAGEMENT WITH SAID SEAT AND BEING DISPOSED BETWEEN SAID CONTROL SECTIONS AND CONNECTED TO ONE THEREOF, SAID ONE CONTROL SECTION AND SAID CORE SECTION HAVING A UNIFORM DIAMETER THROUGHOUT THE COMBINED LENGTHS THEREOF, AND A REDUCED-IN-DIAMETER SHAFT CONNECTING SAID CORE SECTION AND THE OTHER OF SAID CONTROL SECTIONS AND EXTENDING THEREBETWEEN AND ACROSS SAID INLET CHAMBER, SAID CORE SECTION HAVING PASSAGEWAY MEANS THEREIN, SAID PASSAGEWAY MEANS INCLUDING AN AXIALLY EXTENDING ANNULAR FLOW RECESS DISPOSED WITHIN SAID CORE AND OPENING AT ONE END INTO SAID INLET CHAMBER ABOUT SAID SHAFT, THE OTHER END OF SAID RECESS BEING CLOSED, AND A PLURALITY OF AXIALLY EXTENDING, IDENTICAL-IN-LENGTH, RECTANGULAR FLOW SLOTS SPACED ABOUT THE CIRCUMFERENCE OF SAID CORE SECTION AND EXTENDING INWARDLY FROM THE INLET CHAMBER END THEREOF, SAID FLOW SLOTS COMMUNICATING SAID RECESS WITH THE EXTERIOR OF SAID CORE AND BEING SHORTER IN LENGTH THAN SAID RECESS, WHEREBY AS SAID SPOOL IS AXIALLY SHIFTED TOWARD SAID OUTLET CHAMBER THE SLOTS ARE PROGRESSIVELY EXPOSED THEREWITHIN TO THEREBY ESTABLISH A FLUID FLOW PASSAGEWAY BETWEEN SAID CHAMBER AND SAID INLET CHAMBER, AND STOP MEMBERS, EACH FORMED WITH A FRUSTO-CONICAL PORTION SUBSTANTIALLY FILLING SAID CONTROL CHAMBERS TO DIMINISH THE VOLUME OF ACTIVATING FLUID AND TO RENDER A RAPID RESPONSE OF THE CONTROL SECTIONS TO CHANGES OF PRESSURE IN SAID ACTIVATING FLUID, SAID STOP MEMBERS LIMITING THE AXIAL SHIFTING MOVEMENT OF SAID SPOOL SO THAT SAID CONTROL SECTIONS REMAIN CONSTANTLY IN SEALED ENGAGEMENT WITH THEIR RESPECTIVE CONTROL CHAMBERS WHEREBY PRESSURIZED FLUID CONTAINED WITHIN THE INLET AND THE OUTLET CHAMBERS OF THE VALVE IS SEALED FROM SAID CONTROL CHAMBERS.