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:
Jul. 08, 2003
Filed:
May. 31, 2001
Applicant:
Inventors:
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 glaze layer of the spark plug has the composition comprising 1 mol % or less of a Pb component in terms of PbO; 25 to 45 mol % of a Si component in terms of SiO ; 20 to 40 mol % of a B component in terms of B O ; 5 to 25 mol % of a Zn component in terms of ZnO; 0.5 to 15 mol % of Ba and/or Sr components in terms of BaO or SrO; 5 to 10 mol % in total of at least one alkaline metal component of of Na, K and Li in terms of Na O, K O, and Li , respectively, where K is essential; and further, 0.5 to 5 mol % in total of one or two kinds or more of Mo, W, Ni, Co, Fe and Mn in terms of MoO , WO , Ni O , Co O , Fe O , and MnO , respectively.