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. 14, 2004
Filed:
May. 31, 2001
Applicant:
Inventor:
Kenichi Nishikawa, Bisai, JP;
Assignee:
NGK Spark Plug Co., Ltd., Nagoya, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01T 1/300 ; H01T 1/352 ;
U.S. Cl.
CPC ...
H01T 1/300 ; H01T 1/352 ;
Abstract
A spark plug 100 has a glaze layer formed on a surface of an alumina based insulator contains 1 mol % or less of a Pb component in terms of PbO. The glaze layer comprises 35 to 55 mol % of a Si component in terms of SiO ; 15 to 35 mol % of a B component in terms of B O ; 5 to 20 mol % of a Zn component in terms of ZnO; 0.5 to 20 mol % of a Ba component in terms of BaO; and 10 to 15 mol % in total of at least one alkaline metal component of Na, K and Li, in terms of Na O, K O and Li O, respectively.