Automatic stepper for resistance welding
US4885451A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 1988 |
| Grant date | Dec 5, 1989 |
| Priority date | — |
| Expiry date | May 9, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K11/252
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method is disclosed for controlling the magnitude of current delivered through welding electrodes to a workpiece to be welded using resistance welding techniques, in order to prevent weld expulsion and concomitant diminishment of weld quality. Weld expulsion is detected by determining changes in resistance during formation of the weld, by periodically determining the power factor, and the primary circuit of the welding transformer. The power factor is determined by determining the relative timing between the commencement of the applied voltage, the zero crossover point of the applied voltage, and the ensuing zero point of the applied current.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.