Patent ID: 6877717

Claim:
A control valve for controlling fluid flow in a hydraulic control unit, said control valve comprising: a valve body, said valve body comprising a first body portion and a second body portion adjacent said first body portion, said second body portion having a bore formed therein, wherein said first body portion comprises a valve seat, and said second body portion comprises a sleeve mounted on said valve seat, said sleeve having a first ferromagnetic portion adjacent said valve seat, a second ferromagnetic portion, and an annular region defining an area of increased magnetic reluctance between said first ferromagnetic portion and said second ferromagnetic portion of said sleeve, a stepped portion being formed on an inner surface of said sleeve; an armature slidably received in said bore of said second body portion, said armature comprising a first end, said first end of said armature providing a first generally radial flux flow path and at least one of a second generally radial flux flow path and a generally axial flux flow path, said first end of said armature comprising a stepped portion formed on an outer surface of said first end, said stepped portion of said first end of said armature being complementary to said stepped portion formed on said inner surface of said sleeve and comprising at least two steps, said stepped portion of said sleeve being adapted to receive said stepped portion of said armature, at least two steps of said stepped portion of said armature forming radial magnetic poles for the generally radial transmission of magnetic flux from each of said steps of said first end of said armature to respective associated steps of said stepped portion of said sleeve; and an electrical coil disposed about said valve body for selectively inducing a magnetic flux in said armature.