Plasma arc torch interlock with disabling control arrangement system
US4929811A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 5, 1988 |
| Grant date | May 29, 1990 |
| Priority date | — |
| Expiry date | Dec 5, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH05H1/3473
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A plasma arc torch system includes a fault detect circuit for sensing a short between the electrode and the nozzle and disabling the power supply when the short is sensed. A sensing circuit within the torch cable is provided for actuating the fault detect circuit when the cable is severely punctured. The sensing circuit includes a foil embedded within the cable which circumscribes the main conductor to which a drain lead is connected. The drain lead senses a short between the foil and main conductor from a penetrating foreign object and actuates the fault detect circuit. Additionally, the fault detect circuit is effective in combination with a unique continuity interlock circuit disclosed to insure a safe torch. Further, a rectified control circuit is provided to maintain a stable arc preventing erosion of the nozzle and subsequent exposure of the electrode.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.