Igniter electrode life control
US4713574A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 7, 1985 |
| Grant date | Dec 15, 1987 |
| Priority date | — |
| Expiry date | Oct 7, 2005 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T13/32
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The prevention of electrode material erosion by undercutting in the outer electrode shell of igniter electrodes of jet engine ignition systems is prevented by the application of an electrical insulation coating. The coating is applied to the surface of the outer electrode shell which faces the ceramic insulation around the center electrode where erosion patterns are known to occur. The insulation material is selected from electrical insulation substances such as oxides of aluminum, tungsten, magnesium, beryllium or zirconium by choosing a non-porous electrical insulating substance with thermal expansion characteristics approximately equalling those of the outer electrode shell. Since a typical outer electrode shell is composed of 446 stainless steel, an optimum choice for the electrical insulation coating is AL.sub.2 O.sup.3 deposited with a coating thickness of between 5 and 10 mils.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.