Abstract: The preferred field assembly includes a field shell of generally T-shaped radial cross-section and molded of powdered metal, a plastic bobbin for supporting a multiple turn winding, and a plastic bobbin ring which covers part of the field shell and which helps hold the bobbin in assembled relation with the field shell. The bobbin is formed with a terminal block for supporting electrical leads which extend along grooves in the outboard face of one flange of the bobbin and which, together with the end portions of the winding, extend into potting cavities in the outboard face of the bobbin flange. The bobbin ring includes a cap which interfits with the terminal block to retain the leads. Various embodiments of field shells, bobbins and bobbin rings are disclosed.

Abstract: An armature of an electromagnetic clutch is connected to a mounting plate which is coupled to the toothed driven hub of the clutch through the intermediary of an elastomeric spider. If the spider is melted by heat, the mounting plate wedges against the tips of the teeth of the hub and is prevented from flying axially off of the forward end of the hub.