Method to attach the center electrode into a ceramic insulator body of spark plugs
US4097977A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 20, 1977 |
| Grant date | Jul 4, 1978 |
| Priority date | — |
| Expiry date | Jun 20, 1997 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/044
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
To permit simple manufacture and reliable attachment of the center electrode into a ceramic body, an elastic tubular press mold is located in a press body, the press mold being closed off by a movable plug having a needle-like extension with a gripping end formed thereon to receive the center electrode before the plug is inserted into the tubular mold. Ceramic material is then filled into the mold, the plug closing off one end thereof, the mold is closed with a second plug, and pressure in the order of from 250 to 400 bar applied to the outside of the elastic mold to compress the ceramic material and embed the center electrode tip therein. Upon release of pressure, the compressed ceramic, with the center electrode therein can be removed from the holding tip of the needle-like extension of the plug, for subsequent grinding to size, sintering, firing, and glazing, if desired.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.