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. 22, 2010
Filed:
Aug. 28, 2007
Applicants:
Kenichi Kumagai, Nagoya, JP;
Koji Mizoguchi, Nagoya, JP;
Inventors:
Kenichi Kumagai, Nagoya, JP;
Koji Mizoguchi, Nagoya, JP;
Assignee:
NGK Spark Plug Co., Ltd., Nagoya-shi, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01T 1/00 (2006.01);
U.S. Cl.
CPC ...
Abstract
A spark plug including a center electrode; an insulator; a metal shell; a ground electrode; and an annular packing, all as defined herein, wherein the packing has a hardness greater than or equal to a hardness of the stepped portion of the metal shell or has a Vickers hardness of not less than 300 Hv. Preferably, a difference between the hardness of the packing and the hardness of the stepped portion of the metal shell is from 120 Hv to 160 Hv, and the packing has a Vickers hardness of not more than 500 Hv.