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:
Sep. 11, 2012
Filed:
Aug. 23, 2010
Nobuaki Sakayanagi, Toyohashi, JP;
Katsutoshi Nakayama, Toyohashi, JP;
Nobuaki Sakayanagi, Toyohashi, JP;
Katsutoshi Nakayama, Toyohashi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
Peeling resistance of a noble metal chip is improved by reducing a difference in the thermal stress generated between the noble metal chip and a ground electrode. A spark plugincludes an insulator, a center electrode, a metal shell, and a ground electrode, wherein a spark discharge gapis formed between the center electrodeand the noble metal chipbonded to the ground electrode. The ground electrodeis provided with a concave hole portion, and 70% or more of the noble metal chipis bonded to the hole portionof the ground electrodethrough a fusion portionformed by fusing the noble metal chip and the ground electrodeto each other by emitting a laser beam or the like from the side surface of the noble metal chip. A gapis formed between the noble metal chipand at least a part of an inner wall surfaceS of the hole portionso as to be more than 0 mm and equal to or less than 1.0 mm in the direction perpendicular to the central axis CLof the noble metal chip