Patent · US Expired

Spark plug with a surface discharge section

US4939409A · kind A · utility

15Cited by

2References

5Claims

0Family size

Assignee

Robert Bosch GmbH · DE

Inventors

Karl-Hermann Friese · Leonberg, DE
Werner Grunwald · Gerlingen, DE
Kurt Schmid · Ditzingen, DE

Key dates

Filing date	Dec 7, 1988
Grant date	Jul 3, 1990
Priority date	—
Expiry date	Dec 7, 2008

Classification

Technology area (CPC H)Electricity
CPC primaryH01T13/52
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A spark plug with a surface discharge section for internal combustion engines comprising an insulation body having an inner cavity for receiving a mass of an electrically conductive material, and a bore extending from the inner cavity and through which extends a central electrode which is formed integral with the surface discharge surface, is made of an electrically non-conductive material, and has on an outer surface thereof in the area of the mass and the bore an electrically conductive film, and, in the area defining the surface discharge section a film having no intrinsic conductivity after sintering.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.