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:
Jan. 15, 2013
Filed:
Jul. 12, 2010
Nobuaki Sakayanagi, Toyohashi, JP;
Katsutoshi Nakayama, Nagoya, JP;
Nobuaki Sakayanagi, Toyohashi, JP;
Katsutoshi Nakayama, Nagoya, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
Separation of a noble metal tip is prevented and wear resistance is enhanced, while the increase in manufacturing cost is suppressed. A spark plugincludes a center electrodeand a noble metal tip. The center electrodeand the noble metal tipare joined to each other through a molten portion. An area of an interface between the noble metal tipand the center electrodeis set to be 5% or less with respect to a cross-sectional area of the noble metal tipwhich is perpendicular to an axial line CLat a portion of an outer surface of the noble metal tipwhich is nearest to the molten portion. In the cross section including the axial line CL, supposing that a length of the portion of the molten portionin the axial line CLwhich is exposed to the outer surface is A (mm), and a width of the noble metal tipis B (mm), B/A≦6 is satisfied. The portion of the molten portion, of which a length along the axial line CLis A/1.5, is located further outwards radially than a position which comes in by as much as B/4 from the outer circumference of the noble metal tip