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:
Mar. 08, 2005
Filed:
Jul. 16, 2003
Masahiro Ishikawa, Aichi, JP;
Masahiro Ishikawa, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A front end portion of a center electrodeis a circular cylindrical center-electrode noble-metal ablation resistance portionwhose radius r mm and length l mm are determined so as to satisfy 5≦l/r<20. An ignition-performance-improving ground electrodeis configured such that a distal end portion thereof is bent in a direction toward the center electrode; and a rear end-edgeof a distal end surfaceis located frontward in relation to a front end surfaceof the center-electrode noble-metal ablation resistance portion. In orthogonal projection on a projection plane P perpendicularly intersecting an axis O of the center electrode, the rear end-edgeis located outward in relation to the front end surfaceof the center-electrode noble-metal ablation resistance portion. A portion of the ignition-performance-improving ground electrodewhich includes at least the rear end-edgeis a ground-electrode noble-metal ablation resistance portion