ELECTROMAGNET WITH EXTERNAL VALVE-TYPE PULL-IN ARMATURE Russian patent published in 1995 - IPC

FIELD: electrical engineering. SUBSTANCE: core of electromagnet with external valve-type pull-in armature is hollow structure with heightwise variable internal diameter; variable thickness of wall formed by external and internal surfaces meets following relation; , where hm, e, q is wall thickness; d₁ is external diameter of core top portion; d₂ is external diameter of core base; Φ is magnetic flux in core; external and internal surfaces of coil follow external surface of core. Internal surface of core may be made in the form of elliptic paraboloid or truncated cone. EFFECT: improved design. 3 cl, 3 dwg