Patent ID: 7458395

Claim:
A pressure control valve comprising: a housing; a supply port at a first end of said housing; a control port at a first end of said housing; an exhaust port at a second end of said housing; a primary poppet and a primary seat, which provide control pressure feedback acting to open said primary poppet, wherein said primary poppet has a larger diameter and is operably associated with said exhaust port; a secondary poppet and a secondary seat operably associated with said supply port and said control port, wherein said secondary poppet has a smaller diameter which partially offsets the control feedback pressure of said primary poppet; a hollow valve shaft including both poppets, slidably disposed between said primary seat and said secondary seat, wherein said hollow valve shaft allows flow and pressure communication between said primary poppet and said secondary poppet and provides viscous dampening of said valve; a solenoid actuator having an armature fixed to said valve shaft allowing for the positioning of said valve shaft between said primary seat and said secondary seat to achieve variable pressure control proportional to the current applied to said actuator to regulate pressure to said control port; a lower bearing supporting said valve shaft having an inner diameter sized approximately the same as the secondary poppet diameter and located at the supply port such that said bearing acts as a pressure boundary minimizing the area of the movable valve shaft on which supply port pressure acts; and an upper bearing located adjacent to the larger primary poppet supporting said valve shaft and minimizing the transfer of ferrous contamination for controlled fluid to working air gaps of said actuator.