Patent ID: 8443839

Claim:
A hydraulic control valve comprising: a valve body; a selectively energizable coil; an armature positioned adjacent the coil; the coil being energizable to generate a magnetic force that moves the armature from a first position to a second position; a pole piece positioned to establish a gap between the pole piece and the armature and having a cavity that forms an opening at the gap; a piston extending from the armature into the cavity of the pole piece and movable with the armature; wherein the valve body, the armature, and the piston are configured so that the armature is biased to seat at a first valve seat in the first position by pressurized fluid; wherein the magnetic force required to move the armature away from the first valve seat is a function of the difference between an area of the piston and an area defined by contact of the armature at the first valve seat; a valve stem extending from the armature opposite the piston and movable with the armature; wherein the armature and the valve stem include a first poppet and a second poppet; wherein the valve body defines a supply chamber with the first seat, a second seat, and a control chamber between the first and second seats; wherein the first poppet is configured to sit at the first seat and the second poppet is configured to be spaced from the second seat in the first position to substantially prevent pressurized fluid flow past the first seat and to exhaust fluid from the control chamber past the second seat; and wherein the first poppet is configured to be spaced from the first seat and the second poppet is configured to sit at the second seat in the second position to permit flow of pressurized fluid from the supply chamber to the control chamber and prevent flow from the control chamber to an exhaust port.