Patent ID: 7686039

Claim:
A cartridge valve assembly comprising: a body having a pilot port, a first port, a second port, and a third port fluidly connected to a central bore; a spool positioned within the central bore and being movable between at least a first position and a second position, the spool including: a first chamber at a first end surface of the spool in fluid communication with the pilot port; a second chamber at a second end surface of the spool; a control chamber; and a slug bore extending from the second end surface of the spool to a bottom of the spool, the second chamber being formed within the slug bore of the spool; wherein the area of the first end surface is greater than the area of the second end surface; a passage fluidly communicating the control chamber with the second chamber; a slug member slidably received within the slug bore of the spool, the slug member including a bore forming the second chamber with the second end surface; and a lower stop member disposed between the slug and the body, wherein, in the second position, an upper portion of the lower stop member is received in the slug bore of the spool; and wherein, in the first position, the first port and the second port of the body fluidly communicate with the control chamber, and, in the second position, the second port and the third port fluidly communicate with the control chamber.