Solenoid valve

Claim 1

A solenoid valve comprising: a molded one-piece valve body, said body including a relatively large diameter cup-shaped housing having an annular side wall, a back wall, and an open inlet mouth for admitting liquid into the housing interior, said body also including a relatively small diameter elongated tubular extension formed integrally with and projecting outwardly from the housing back wall on the housing axis for receiving liquid from the housing interior, said body also including a single annular valve seat formed within the tubular extension as an integral part thereof, said valve seat being formed as an inwardly radiating flange adjacent the end of the tubular extension remote from the cup-shaped housing; a movable valve element cooperable with said valve seat to control liquid flow through the tubular extension, said valve element comprising an elongated armature plunger slidably positioned within the tubular extension in the space between the cup-shaped housing and the valve seat, said armature plunger being cross-sectioned to permit liquid to pass from the housing through the valve seat when the armature is axially spaced from the valve seat; a solenoid coil magnetic frame assembly telescoped onto the tubular extension in the area thereof between the housing and the valve seat, said frame comprising a U-frame member having a web wall paralleling the tubular extension and two flanges lying against the ends of the coil, said frame further comprising magnetically permeable sleeves extending axially from the frame member flanges into the coil in surrounding relation to the tubular extension, said sleeves terminating short of one another to define a centering gap to be bridged by the armature when the coil is energized, said armature being dimensioned so that movement thereof to a position bridging the magnetic gap causes said armature to open the flow path through the valve seat; and a resilient deformable flow rate control member disposed within the cup-shaped housing to regulate the liquid flow therethrough; wherein the improvement comprises: a molded plastic insert disposed within the cup-shaped housing, the insert having a cup-shaped portion and a tubular extension, the cup-shaped portion adapted to contain the flow rate control member and the tubular extension of said insert extending into the tubular extension of said valve body a sufficient distance to limit the travel of said armature plunger so that said plunger does not pass said centering gap when the coil is energized.