The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 03, 1992
Filed:
Jul. 21, 1989
BERU Ruprecht GmbH & Co. KG, both of, DE;
Vacuumschmelze GmbH, both of, DE;
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.