Directional control valve

Abstract

Abstract A DIRECTIONAL CONTROL VALVE FOR A HYDRAULIC FUNCTION INCLUDES A PAIR OF SLEEVE-LINED BORES THAT HAVE CONSECUTIVE FIRST, SECOND AND THIRD AXIALLY-SPACED GROOVES BETWEEN A CLOSED END AND AN END WHICH OPENS INTO A FLUID RESERVOIR. THE FIRST, SECOND AND THIRD GROOVES OF ONE BORE ARE, ON THE ONE HAND, RESPECTIVELY CONNECTED TO A SOURCE OF FLUID PRESSURE, ONE FUNCTION CONTROL PORT AND THE OTHER FUNCTION CONTROL PORT AND ARE, ON THE OTHER HAND, RESPECTIVELY CONNECTED TO THE FIRST, THIRD AND SECOND GROOVES OF THE OTHER BORE. VALVE PISTON ARE AXIALLY SHIFTABLE IN THE BORE AND HAVE FIRST AND SECOND VALVE SURFACES NORMALLY BIASED AGAINST FIRST AND SECOND VALVE SEATS IN THE BORE TO ESTABLISH A NEUTRAL CONDITION WHEREIN FLUID PRESSURE IS BLOCKED IN AND FROM THE FUNCTION CONTROL PORTS. THE VALVE PISTONS HAVE HEADS, BETWEEN THE FIRST GROOVES AND CLOSED ENDS OF THE BORES, ACROSS WHICH PRESSURE DROPS ARE SELECTIVELY INDEPENDENTLY OR SIMULTANEOUSLY CREATED FOR SHIFTING THE VALVE PISTON TO RESPECTIVELY ESTABLISH FIRST AND SECOND ACTIVE CONDITION OR A FLAT CONDITION WHEREIN ONE OR THE OTHER OF THE CYLINDER CONTROL PORTS IS CONNECTED TO THE FLUID PRESSURE WHILE THE REMAINING CONTROL PORT IS CONNECTED TO THE RESERVOIR OR WHEREIN BOTH CONTROL PORTS ARE CONNECTED TO THE RESERVOIR. THE PRESSURE DROPS ARE SELECTIVELY CREATED BY PERMITTING FLOW FROM THE FIRST GROOVES OF THE BORES TO THE RESERVOIR VIA ORIFICES IN THE HEADS OF AND NORMALLY CLOSED AXIAL PASSAGES THROUGH THE VALVE PISTONS. IN ONE EMBODIMENT, A MECHANICAL CONTROL OPENS THE AXIAL PASSAGES TO PERMIT FLOW AND IN A SECOND EMBODIMENT, AN ELECTRICAL CONTROL OPENS THE AXIAL PASSAGES TO PERMIT FLOW.

Inventors

• 👤 Paul Edmund Hanser

Bibliographic Details