Electrode for high current density plasma arc torch

US5310988A · kind A · utility

Assignee

• Hypertherm, Inc. · US

Inventors

• Richard W. Couch, Jr. · Hanover, US
• Nichols A. Sanders · Hartford, US
• Lifeng Luo · Shaoyang City, CN
• Zhipeng Lu · Hanover, US
• Patrik Backander · carrer de Sertori, SE
• John Sobr · Lebanon, US

Key dates

• Filing date: May 20, 1992
• Grant date: May 10, 1994
• Expiry date: May 20, 2012

Classification

• Technology area (CPC H): Electricity
• CPC primary: H05H1/3452
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

The diameter of a hafnium insert press fit into the bottom end of a copper electrode varies as a function of the level of current carried by the electrode. The diameter is the minimum necessary to support emission at that current level while also protecting the copper body against attack by the arc. The insert is generally circular and preferably extends completely through the bottom wall to a circulating flow of cooling water at a hollow interior of the electrode. The bottom wall includes an annular recess in a portion of the copper wall surrounding the insert. A coolant inlet tube extends into the recess in a spaced relationship to provide a high flow velocity of the coolant over the interior rear surface of the electrode.