Patent · US Expired

Spark plug with specific metal shell coating

US6236148A · kind A · utility

10Cited by
1References
8Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 25, 2000
Grant dateMay 22, 2001
Priority date
Expiry dateFeb 25, 2020

Classification

  • Technology area (CPC F)Mechanical Engineering; Lighting; Heating
  • CPC primaryF23Q2007/004
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

In a glow plug and a spark plug, the surface of a main metal shell is coated with a chromate film in which the quantity of trivalent chrome is 95 wt % or more of the contained chrome components and which has a thickness of 0.2 .mu.m to 0.5 .mu.m.

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