Patent ID: RE40265

Claim:
A process for forming a resistance welding electrode comprising the steps of: providing a billet formed from a high conductivity metal, said billet including a first portion having a first inner cavity therein; inserting a dispersion strengthened copper insert into said first inner cavity of said billet thereby forming an insert-containing billet; and deforming said insert-containing billet so as to mechanically lock said insert in place in said billet, said deformed insert-containing billet comprising a resistance welding electrode , said deforming step comprising: placing said insert - containing billet into a first inner cavity of a first insert - containing billet forming die, said first inner cavity having a first generally rounded lower portion; applying pressure with a first forming punch to a second portion of said insert - containing billet such that said insert - containing billet is initially deformed so as to have a first shape; placing said insert - containing billet having said first shape into a second inner cavity of a second insert - containing billet forming die, said second inner cavity having a second generally rounded lower portion; applying pressure with a second forming punch to said second portion of said initially deformed insert - containing billet such that said initially deformed insert - containing billet is further deformed so as to have a second shape; placing said insert - containing billet having said second shape into a third inner cavity of a third insert - containing billet forming die; and configuring a third forming punch to include on a billet - engaging surface thereof a reduced contact area; applying pressure with said third forming punch to said second portion of said further deformed insert - containing billet such that said further deformed insert - containing billet is additionally deformed so as to have a third shape, said insert of said additionally deformed insert - containing billet having a substantially hourglass shape such that said insert is mechanically locked in place within said billet .