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:
Dec. 30, 1986
Filed:
May. 30, 1985
Morihiro Atsumi, Okazaki, JP;
Hitoshi Yoshida, Okazaki, JP;
Novuei Ito, Nukata, JP;
Kinya Atumi, Toyohashi, JP;
Nippondenso Co., Ltd., Kariya, JP;
Nippon Soken, Inc., Nishio, JP;
Abstract
A sintered ceramic heater, particularly a heater for a glow plug of a diesel engine, includes a sintered ceramic heater, which generates heat upon receiving an electric current, supported by an electrically insulating sintered ceramic body. The heater element includes a U-shaped cross-section outer portion integrally sintered with and covering a central portion. Each portion is formed of a sintered ceramic body of a mixture of electrically conductive ceramic powder having an average diameter of not more than 2 .mu.m and selected from the group consisting of MoSi.sub.2, WSi.sub.2, TiB.sub.2 and TiC, and 35-75 mol % of electrically insulating ceramic powder, e.g., Si.sub.3 N.sub.4. The central and outer portions have the same composition. However, in the central portion the average particle diameter of the conductive ceramic powder is equal to or larger than that of the insulating ceramic powder, whereas in the outer portion the average particle diameter of the conductive ceramic powder is not more than half that of the insulating ceramic powder. The specific resistance of the central portion is not less than 1.7 times as large as that of the outer portion so that the heat is generated by current flow through the outer portion of the ceramic heater.