Patent · US Expired

Protective device for the welding circuit of welding power sources

US4507699A · kind A · utility

5Cited by
2References
4Claims
0Family size

Assignee

Inventor

Key dates

Filing dateDec 17, 1982
Grant dateMar 26, 1985
Priority date
Expiry dateDec 17, 2002

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB23K9/10
  • WIPO fieldMachine tools
  • WIPO sectorMechanical engineering

Abstract

A system to prevent a dangerous contact voltage in a welding apparatus by providing a protective device for cutting off the power for welding. The welding system has a power source including a primary circuit and a secondary circuit. An electrode receiving the power welds workpieces which are successively inserted and removed into electrical contact in the welding system. A protective ground is provided between the housing for the power source and ground. To prevent dangerous grounding during the welding operation, there is connected between the workpiece lead in the secondary and the housing a device which monitors both the current to the protective wire ground and the voltage between the workpiece lead and the housing. This monitor device controls a power cut-off switch. The current is monitored through a current sensor which is connected to the monitor device and the current sensor is also connected in series between the housing and the protective ground. In this way, it is possible to disconnect the power to the electrode when predetermined circuit and voltage limits are exceeded.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.