Method for starting and stopping a plasma arc torch
US9000322B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 21, 2011 |
| Grant date | Apr 7, 2015 |
| Priority date | — |
| Expiry date | Aug 14, 2033 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/3457
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A method of starting a plasma arc torch is provided that includes directing a pre-flow gas and a start shield gas through the plasma arc torch during generation and transfer of a plasma arc, and switching from the pre-flow gas to a plasma gas, and switching from the start shield gas to a primary shield gas after transfer of the plasma arc to a workpiece. A method of stopping a plasma arc torch is also provided that includes directing a plasma gas and a primary shield gas through the plasma arc torch during steady-state operation, and switching from the primary shield gas to a stop shield gas during ramp down of an operating current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.