Spark plug with tapered fired-in suppressor seal
US7443089B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jun 16, 2006 |
| Grant date | Oct 28, 2008 |
| Priority date | — |
| Expiry date | May 2, 2027 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/41
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A spark plug (10) for a spark ignited internal combustion engine includes a suppressor seal pack (54) interposed between an upper terminal stud (46) and a lower center electrode (60). The suppressor seal pack (54) includes a top layer of conductive glass (52) surrounding the bottom end (50) of the terminal stud (46) and a lower glass seal layer (58) surrounding a head (62) of the center electrode (60). A resistor layer (56) fills the space between the conductive glass layers (52, 58). The resistor layer (56) has a larger first cross-sectional area (76) at its upper end and a smaller second cross-sectional area (78) at its lower end. A reducing taper (80) establishes a progressive transition between the greater and lesser cross-sectional areas (76, 78). The reducing taper (80) is located in a large shoulder region (LS) which is defined as the longitudinal dimension between the theoretical reference point (70) at the filleted transition (26) and the theoretical reference point (68) at the upper seat (17). The suppressor seal pack (54) is of the fired-in variety in which each layer (54, 56, 58) is separately filled as a granular material, tamped and then cold pressed using the termina…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.