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:
Apr. 16, 2013
Filed:
Sep. 16, 2010
Applicants:
Hiroaki Nasu, Gifu, JP;
Akito Sato, Obu, JP;
Kazuhiro Kodama, Hekinan, JP;
Inventors:
Assignee:
NGK Spark Plug Co., Ltd., Nagoya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01T 13/20 (2006.01);
U.S. Cl.
CPC ...
Abstract
Provided is a spark plug that is excellent not only in salt resistance but also in stress corrosion cracking resistance. The spark plug includes a metal shell covered by a composite layer including a nickel plating layer and a chromate layer formed on the nickel plating layer. The chromate layer has a film thickness of 2 to 45 nm and Cr element concentration of not more than 60 at % and contains Ni in addition to Cr.