Method for manufacturing a center electrode for a spark plug
US4725254A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1986 |
| Grant date | Feb 16, 1988 |
| Priority date | — |
| Expiry date | Nov 24, 2006 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01T21/02
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A method of manufacturing an electrode (20) for a spark plug (32) wherein a platinum cup member or (54) cap is attached to a tip (12) that extends from an extruded inconel body (10). The inconel body (10) is sequentially extruded from a cylindrical blank to produce a tip (12) on a first end (12) and a cup shaped (16) opening that extends from a second end (14) toward the first end (12). A copper core (18) is inserted into the cup (16) and the cylindrical blank (10) thereafter extruded to a substantially final length for the resulting center wire (20). In order to assure a uniform thickness, a source of platinum (38) is roller into a thin strip and a (44) disc is punched therefrom. The disc (44) is formed into a cap member (54) which has the shape of a cup . The resulting cap member (54) and center wire (20) are placed in a fixture and the cap member (54) is moved toward the center wire (20) until the cap member surrounds the tip (12). Thereafter electrical current is passed through the cylindrical body (20) and cap member (54). The electrical current is terminated when the thermal energy heats the inconel adjacent the junction to its melting point. A compressive force is maintained…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.