The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 02, 2003
Filed:
Nov. 19, 2001
Ichiro Katayama, Nagaoka, JP;
Hideo Wakui, Tokyo, JP;
Union Tool Company, Tokyo, JP;
Abstract
A method of joining a sintered hard alloy member such as a cylindrical rod-shaped twist drill bit blank made of material whose main component is tungsten carbide to a softer metal member such as a stainless steel shank includes the steps of connecting the hard alloy member and the metal member to separate electrodes and applying a longitudinally directed force couple to the hard alloy member and metal member to press end faces of the members together to form an electrically conductive contact region, and passing a pulse of current through electrodes and of sufficient energy to melt the two end face regions of the members, thereby welding them together. Preferably, the end face of the metal member has a convex conical shape.