Electro-pneumatic valve

Claim 1

An electrovalve comprising: a. a core plunger disposed within the bore of a nonmagnetic tubular member for movement between a pair of end stops, said bore having passage means connected thereto, in which the flow of fluid pressure is controlled by the cooperative relationship of said core plunger with a respective one of said end stops; b. an induction coil to which a source of electric current is connected, said coil being carried by said tubular member in surrounding relationship with a portion of said core and a portion of a magnetic plug mounted at one end of the tubular member where said plug forms a first one of said end stops; c. a magnetic member formed of a material having good magnetic permeability and disposed about the periphery of said coil in generally conforming alignment with the periphery of said tubular member, said magnetic member including an annular pole piece adjacent each end of said coil, said magnetic member, said plug and said core plunger providing a magnetic flux circuit for said coil whereby said pole pieces magnetically connect said magnetic member across said tubular member with said plug and said core plunger when said coil is energized to effect movement of said core plunger; and d. a pair of external collars concentric with the bore of said tubular member, each of said collars separating said induction coil and a respective one of said annular pole pieces to provide in cooperation with said tubular member the supporting structure for said coil, said tubular member further including a pair of shoulders concentric with said bore, each spaced apart from a respective one of said collars to form in cooperation therewith means forming the support structure for said magnetic member.