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:
Jul. 10, 2012
Filed:
Sep. 10, 2008
Reimon Fukuzawa, Aichi, JP;
Tomoaki Kato, Nagoya, JP;
Akira Suzuki, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A spark plug includes: a metal shell having a mounting thread formed with a nominal diameter of M12 or smaller; a ground electrode consisting of a first structural member and at least one ith structural member (i=2, 3, 4, 5) laminated to cover an outer surface thereof, the length of protrusion of the ground electrode from a front end face of the metal shell being 4.5 mm or larger, the ground electrode having a bent portion with a curvature radius of 2.3 mm or smaller; and an electrode tip joined thereto at a position facing the front end of the center electrode and having a protrusion length of 0.5 mm or larger and a cross sectional area of 0.20 to 1.13 mm. The ground electrode has a total thermal conductivity of 35 W/(m·K) or higher at 20° C.