Spark plug and a method of producing the same
US6831397B2 · kind B2 · utility
13Cited by
15References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jan 30, 2002 |
| Grant date | Dec 14, 2004 |
| Priority date | — |
| Expiry date | Mar 29, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/39
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A noble metal chip of which one end is welded to an earth electrode by laser has a sectional area of not less than 0.12 mm2 and not more than 1.15 mm2 at the other end. A length from the surface of the earth electrode to the top surface of the noble metal chip is not less than 0.3 mm and not more than 1.5 mm. An outer surface of the fused junction layer obtained by laser welding between the noble metal chip and the earth electrode has a concave surface, wherein the slope on the plane including the axis of the noble metal chip is curved with a radius R.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.