Patent ID: 7766042

Claim:
A cartridge valve assembly comprising: a body having a central bore, a first port, a second port, and a third port fluidly connected to the central bore; a main spool having a first end and a second end positioned within the central bore between a first stop member and a second stop member, the main spool movable between at least a first position and a second position, wherein the main spool forms, within the central bore, a first chamber between the first end and the first stop member, a second chamber between the second end and the second stop member, and a control chamber between the first and second ends; a balance spring positioned in the first chamber and adapted to apply a force at the first end of the main spool; a first passage fluidly coupling the first chamber to the second chamber; an actuator adapted to apply a force to the first end of the main spool; a feedback spool positioned in the second chamber, the feedback spool having a distal end section slidably positioned in a central bore of the second stop member to form a feedback chamber; a feedback spring positioned in the second chamber around a section of the feedback spool and the second stop member, and adapted to apply a force at the second end of the main spool and urge the main spool from the second position to the first position; and a second passage fluidly communicating the control chamber with the feedback chamber.