Spark plug for internal combustion engine
US5962957A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 24, 1997 |
| Grant date | Oct 5, 1999 |
| Priority date | — |
| Expiry date | Mar 24, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/34
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
By heating a glass sealing material, a center electrode is sealed and fixed within an axial bore of an insulator. Formation of a groove in a head portion of the center electrode makes it possible to protect the head portion of the center electrode from deformation under a pressure which is applied upon filling the glass sealing material in a powder form in the axial bore. The glass sealing material is therefore assured to flow to a peripheral side wall of a flange portion of the center electrode, thereby enhancing mechanical engagement between the center electrode and the insulator, that is, uniting strength for them. A spark plug is hence obtained with improved impact resistance and accordingly, with sufficient durability.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.