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:
Feb. 04, 2014
Filed:
Dec. 25, 2008
Hiroyuki Kameda, Aichi, JP;
Katsutoshi Nakayama, Nagoya, JP;
Kaori Kishimoto, Nagoya, JP;
Tomoaki Kato, Nagoya, JP;
Hiroyuki Kameda, Aichi, JP;
Katsutoshi Nakayama, Nagoya, JP;
Kaori Kishimoto, Nagoya, JP;
Tomoaki Kato, Nagoya, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A spark plug includes a center electrode extending along an axial line, a ground electrode, and a noble metal tip. A center axis of the noble metal tip is displaced from a center axis of the ground electrode toward a base-end side in the axial line. The ground electrode includes an outer layer and an inner layer, and a distal end of the inner layer is closer to the axial line than a base end of the ground electrode. An overlap area between the inner layer and the noble metal tip occupies a ratio of 25% or more in a projective plane defined by projecting, along the center axis, a plane of the ground electrode viewed from a distal-end face on a cross section of the ground electrode in which a maximum cross-sectional area of the inner layer is achieved, among cross sections orthogonal to the center axis.