Abstract: A normally closed, electrical solenoid actuated, pressure compensated, proportional, hydraulic flow control valve (4) includes a fluid flow control poppet valve (5), a pilot operator (6), a solenoid operator (7) and a pressure compensator (8). The poppet valve (5) includes a poppet (31) and a seat (32). The pilot operator (6) includes a pilot (36) and a pilot seat (37). The solenoid operator (7) includes a solenoid tube (42) and an armature (44). The pressure compensator (8) Includes a pressure balanced pressure compensator spool (58), a smaller diameter differential pressure compensator control piston (64), and springs (61) that balance the forces on the compensator control piston (64). The compensator control piston (64) moves the compensator spool (58) to maintain a substantially constant pressure differential across the poppet valve (5). The valve (4) may be used in a variety of hydraulic systems. A similar normally opened valve (104) is also disclosed.

Abstract: A three position solenoid operated cartridge valve comprises an elongate cylindrical cartridge valve housing having an axial through bore defining an interior chamber. A port end of the chamber comprises an end port and a plurality of axially spaced side openings define first, second and third side ports. An axial opposite end comprises a sleeve end receivable in a solenoid, in use, and a spring chamber intermediate the port end and the sleeve end. A valve member is movable in the chamber at the port end between a neutral position and opposite first and second actuated positions for selectively controlling fluid flow between the end port and the side ports. A solenoid plunger is movable in the sleeve end of the interior chamber. A rod operatively connects the valve member to the solenoid plunger for positioning the valve member responsive to movement of the solenoid plunger using a pull force or a push force.

Abstract: A fluid flow control valve having a block defining a spool valve chamber and ports communicating with the chamber. A spool valve assembly for selectively controlling flow through the valve includes a spool body having an annular end provided with at least one axially outwardly opening notch. A spool end on the spool body defines a first frustoconical, axially outwardly narrowing outer surface concentrically within the annular end of the spool body, and a second, frustoconical, axially outwardly widening radially outer surface extending axially outwardly from the axial outer end of the first frustoconical surface and axially outwardly of the spool outer end.