Patent · US Expired

Glow plug having cobalt/iron alloy regulating filament

US5093555A · kind A · utility

9Cited by

4References

10Claims

0Family size

Assignees

Beru Ruprecht GmbH & Co. KG · DE
Vacuumschmelze GmbH & Co. KG · DE

Inventors

Bertram Dupuis · Ludwigsburg, DE
Max Endler · Ludwigsburg, DE
Paul Bauer · Steinheim an der Murr, DE

Key dates

Filing date	Jul 21, 1989
Grant date	Mar 3, 1992
Priority date	—
Expiry date	Jul 21, 2009

Classification

Technology area (CPC H)Electricity
CPC primaryH01C7/02
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

A sheathed-element glow plug has a front resistance heating filament connected in series with a rear resistance regulating filament having a higher positive temperature coefficient (PTC) than the front filament. The rear filament is made of cobalt/iron alloy consisting of 44-80% by weight cobalt, 20-35% by weight iron, up to 1% miscellaneous components and nickel, if present, in an amount of 0 to less than 15% by weight. The alloy has a resistance ratio (20.degree.-1000.degree. C.) which is no more than approximately 7.5 in the range from about 100.degree. C. to between about 400.degree. C. to about 600.degree. C., and which ratio rises sharply to values from 7.5 to greater thin 12 in the range from 400.degree. C. to 600.degree. C. to about 900.degree. C.

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