Control valve having an actuating drive and method therefor

A valve apparatus for controlling fluid flow, comprising:

• (a) a valve, including a substantially cylindrical valve casing having an inlet port and an outlet port for fluid and a shut-off piston slidable within said valve casing;
• (b) a cylindrical elongated armature capsule arranged in coaxial and in fluid-tight relation with said valve casing;
• (c) an electromagnetic drive element having an annular magnet coil surrounding said armature capsule in coaxial relation thereto;
• (d) an armature coaxially located on said magnet coils and axially slidable wig said armature capsule;
• (e) a controller element having an annular sensing coil coaxially arranged on said armature capsule adjacent said magnet coil, and an armature insert coaxially located in said sensing coil and being axially displaceable within said capsule relative to said sensing coil, to generate a signal therein dependent on the relative axial position of said armature insert;
• (f) a tappet slideably supported in said armature capsule and extending into said valve casing for cooperation with said shut-off piston, said magnet armature, said armature insert and said tappet being rigidly interconnected with each other, to slideably drive said shut-off piston via said drive element and to correspondingly displace said armature insert,
• whereby a signal for the position of said slidable shut-off piston is obtained by said controller element via a coaxial displacement of said armature insert with respect to the shut-off piston.