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:
Jun. 03, 2014
Filed:
Aug. 08, 2011
Kazuhiro Kodama, Hekinan, JP;
Hiroaki Nasu, Gifu, JP;
Kazuhiro Kodama, Hekinan, JP;
Hiroaki Nasu, Gifu, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
An adhesion of a nickel plating layer to a metal shell is improved, and an effect of improving a corrosion resistance by providing the nickel plating layer is sufficiently exerted. A spark plugincludes a cylindrical metal shellthat extends in an axial CLdirection, and a nickel plating layerthat is made of metal containing nickel as a main component and covers an outer surface of the metal shell. In a monochrome image of 256 gradations where black is 0 and white is 255, which is obtained by observing a cross-section perpendicular to an outer surface of the nickel plating layer by a transmission electron microscope with an acceleration voltage of 200 kV, an average value in 256 gradations of the monochrome image is 170 or larger and 230 or smaller.