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:
Jun. 24, 2003
Filed:
Nov. 22, 2000
Applicant:
Inventors:
Assignee:
Komatsu Industries Corporation, Komatsu, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B23K 1/000 ;
U.S. Cl.
CPC ...
B23K 1/000 ;
Abstract
The invention prolongs the electrode lifetime of plasma machining electrodes having a hafnium or zirconium insert. A hafnium or zirconium insert inserted into the tip of a copper holder protrudes from the tip of the copper holder . The protrusion length L is not larger than the diameter D of the insert, preferably not larger than 0.5 mm. The protruding portion of the insert has a rounded section without sharp angles. The rear surface of the insert is exposed to the flow of the cooling water inside the electrode. At least during the generation of the pilot arc, a plasma gas containing at least 5 mol % nitrogen is used.