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:
Nov. 24, 2015
Filed:
May. 19, 2015
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Norihide Kachikawa, Seto, JP;
NGK SPARK PLUG CO., LTD., Aichi, JP;
Abstract
A spark plug includes a portion from a position at a distance of 0.1 mm from a base end to a distal end that is categorizable into a high hardness portion and a low hardness portion using a hardness distribution of a ground electrode, the high hardness portion being a portion from the position at a distance of 0.1 mm from a base end to a position at a distance of 0.1×n (mm) from a base end, the low hardness portion being a portion from a position at a distance of 0.1×(n+1) (mm) from the base end to the distal end, where 'n' is a natural number. The low hardness portion includes a portion that has a largest curvature in the ground electrode. A highest hardness of the low hardness portion is lower than a lowest hardness of the high hardness portion.