Fuse element termination for current-limiting fuse

Abstract

A current-limiting fuse comprises a hollow insulating housing; metallic end cap assemblies at opposite ends of the housing; a multi-ribbed dielectric spider assembly having metallic terminator plates connected at opposite ends disposed within the housing with each terminator plate electrically and mechanically connected to an associated end cap assembly; a plurality of fusible elements helically wound on the spider assembly with their ends electrically and mechanically secured to the terminate plate; a visual indicator pin mounted on one end of the spider assembly and movable by a biasing spring from a retracted position wherein it is secured by a fusible wire to a tripped (fuse-blown) position wherein it projects through aligned holes in an associated terminator plate and end cap assembly; and granular dielectric material filling the housing. Each terminator plate comprises axially inwardly extending relatively massive arcing electrodes (one for each fusible element) around which end portions of the fusible elements are wound. Each end portion of an element extends either through a hole in the arcing electrode to which it is spot-welded or through a hole in the terminator plate to which it is welded. The fusible wire has one end mechanically secured to the pin, is helically wound through axially spaced apart holes formed in the ribs of the spider assembly, and has its other end mechanically anchored to a rib in the spider assembly.