Coil body for miniature relays and the like

摘要

A coil body consists of a coil tube having flanges integrally formed onto the ends and having an axially through-extending opening. This core opening is formed by a successive arrangement of radial recesses which alternately extend through the coil tube wall from opposite sides. These radial recesses are formed by of reciprocally opposed projections of two cooperating mold halves of an injection molding tool. Such an arrangement permits manufacture of winding coil bodies with a simple two-part mold, eliminating a need for moveable components for forming the axial spindle core opening during the molding operation. The resulting coil body includes the continuous axial spindle opening defined by wall segments around its entire periphery and for easy attachment to a winding spindle for winding.