PROPORTIONAL ELECTROMAGNET Russian patent published in 1998 - IPC

FIELD: proportional direct-stroke cylindrical electromagnets primarily used for hydraulic control devices. SUBSTANCE: electromagnet has ferromagnetic body, ferromagnetic flange, cylindrical ferromagnetic sleeve with nonmagnetic gap, ferromagnetic armature moving within sleeve; one end of sleeve is inserted in body and its other end receives flange which in its turn in inserted in body with its wide part; electromagnet components are made as follows: effective end surface of armature has trapezoidal annular groove with angle of groove-section trapezium base of 60^°<α<80^° and groove depth 0.6 to 0.8 of armature working stroke; end surface of flange carries bead of appropriate shape; coil is wound on former built up if sleeve, flange, and washer. EFFECT: enlarged working stroke at high tractive force of electromagnet. 6 dwg