Gas mixtures for plasma arc torch cutting and marking systems
US5773788A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 3, 1996 |
| Grant date | Jun 30, 1998 |
| Priority date | — |
| Expiry date | Sep 3, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K35/0211
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of operating a plasma arc torch for marking a metallic workpiece spaced a stand-off distance from the torch utilizes a torch that includes a body, an electrode, and a nozzle mounted in the body so as to define a plasma chamber. The nozzle has a central passage and an exit orifice through which the transferred arc passes to the workpiece. The method also utilizes a plasma gas flow through the body to form a pilot arc in the plasma chamber and then to form a transferred arc between the electrode and the workpiece. The method includes forming the plasma gas flow with a selected mixture of hydrogen and an inert gas. The percentage of hydrogen in the selected mixture is between 0% and 35%. The percentage of inert gas in the selected mixture is between 100% and 65%. The inert gas may be argon.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.