Abstract: A solenoid-operated control valve has a primary piston and a secondary piston located within a sleeve, and a solenoid coil disposed about the sleeve to effect movement of the primary piston. The primary and secondary pistons are independently movable along the sleeve. The secondary piston defines a pilot orifice connected with a center passage. The primary piston has a seal pin that extends into the pilot orifice of the secondary piston to block and unblock the center passage with movement of the primary piston in relation to the secondary piston. A spiral cut scarf ring disposed about the secondary piston is in contact with both the secondary piston and the sleeve to allow controlled leakage of a fluid through the valve via space between the secondary piston and the sleeve. The leaked fluid is permitted to collect in a cavity between the primary and secondary pistons.

Abstract: A solenoid-actuated four-way fluid control valve assembly has a body assembly mounting a pair of solenoids and defining two valve chambers each containing an axially elongated generally L-shaped plunger assembly and a pair of valve seats. Each plunger is spring biased to closing engagement with one of the valve seats and is shiftable axially to another position to open the one valve seat and close the other in response to energization of an associated one of the solenoids. A transfer plate mounted on the valve body determines flow paths through the valve assembly and carries needle valves for selectively regulating flow in each of the latter paths. The two plunger assemblies, the biasing springs therefor, and a cartridge which provides a closure for the two valve chambers comprise a cartridge assembly which may be removed from the valve body as a unit to facilitate repair or replacement of operational parts of the valve assembly.

Abstract: A solenoid-operated fluid control valve has an armature assembly which includes a reciprocally moveable impact plunger and a seal pin reciprocally mounted in the plunger and projecting therefrom. A valve insert defines a valve seat and has an integral a guide portion which includes a bore slidably receiving an associated projecting portion of the seal pin therein to guide it into seating engagement with the valve seat and to maintain it in alignment with the valve seat at all times.

Abstract: A solenoid-actuated four-way fluid control valve assembly has a body assembly mounting a pair of solenoids and defining two valve chambers each containing an axially elongated generally L-shaped plunger assembly and a pair of valve seats. Each plunger assembly is spring biased to closing engagement with one of the valve seats and is shiftable axially to another position to open the one valve seat and close the other in response to energization of an associated one of the solenoids. A transfer plate mounted on the valve body determines flow paths through the valve assembly and carries needle valves for selectively regulating flow in each of the latter paths. The two plunger assemblies, the biasing springs therefor, and a cartridge which provides a closure for the two valve chambers comprise a cartridge assembly which may be removed from the valve body as a unit to facilitate repair or replacement of operational parts of the valve assembly.