Fabricated lifting magnet assembly

Abstract

A lifting magnet assembly is disclosed which has a permeable magnetic case with a central core and an outer peripheral wall. Electrical winding means surrounds the coil and is inside the outer wall. A composite magnetically permeable case top is provided in the magnet assembly, the composite case top including a cast steel member and a uniform thickness top plate welded together. The composite case top is welded to the core and to the outer peripheral wall, and the cast steel member is generally in the form of a spider with a plurality of arms extending from a central annular portion. This cast steel member performs the triple function of stiffening the steel top plate, providing the connector means to the lifting chain, and providing a flux path supplemental to the top plate for the magnet flux. A single size of cast steel member may be used for a plurality of sizes of magnet assemblies. A central pole piece is secured to the outer end of the core, and transverse forces on the edge of the central pole piece are transmitted to the core by a steel cylinder recessed into apertures in both the core and the pole piece. The foregoing abstract is merely a resume of one general application, is not a complete discussion of all principles of operation or applications, and is not to be construed as a limitation on the scope of the claimed subject matter.