Method of forming spark plug bodies
US4352283A · kind A · utility
40Cited by
8References
4Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Mar 6, 1981 |
| Grant date | Oct 5, 1982 |
| Priority date | — |
| Expiry date | Mar 6, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T21/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of manufacturing a hollow spark plug body having a cylindrical central portion (28), a first end portion (10) of smaller circular radial cross-section and a second end portion of non-circular radial cross-section, e.g. hexagonal, and of smaller maximum diameter than the central portion by cold extruding the both end portions. The second end portion is extruded in two stages, the first involving the formation of a recess in one end of a cylindrical blank, the second involving extrusion the blank between a die (19) and a mandrel (21) which moves with the blank during extrusion.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.