Insulator strength by seat geometry
US8643263B2 · kind B2 · utility
4Cited by
12References
21Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Dec 10, 2012 |
| Grant date | Feb 4, 2014 |
| Priority date | — |
| Expiry date | Dec 10, 2032 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T21/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug (20) includes an insulator seat angle (αi) of 35° to 50° and an increased insulator thickness (ti) in selected areas around the insulator seat (28). The insulator seat angle (αi) is greater than or equal to a boundary value provided by the equation: 90°−a cos [1−(R1−R2)÷(R4+R5)], and preferably not greater than 150% of the boundary value. The radii (R1, R2, R3, R4, R5) can be adjusted to maximize R4 while maintaining an acceptable R2. A gasket is compressed between the insulator (22) and shell (58), and the inner gasket thickness (tg2) is greater than or equal to 70% of the outer gasket thickness (tg1).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.