Method of ensuring the maintenance of constant quality of spot welds
US4329561A · kind A · utility
85Cited by
7References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Feb 14, 1979 |
| Grant date | May 11, 1982 |
| Priority date | — |
| Expiry date | Feb 14, 1999 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB23K11/25
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of improving the reproducibility of the welds in an electric spot welding machine comprises prior to the initiation of a welding operation passing a preheating current of lower magnitude than the welding current through the parts to be welded. When either the total electrical workpiece resistance of the parts to be welded has fallen below a given limit or when its rate of decrease is slower than a predetermined limit the changeover from preheating current to welding current is effected.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.