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. 25, 2017
Filed:
May. 31, 2016
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Naofumi Yamamura, Nagoya, JP;
Kuniyuki Ishii, Gifu, JP;
Naoya Onoda, Komaki, JP;
Hiroyuki Odo, Kounan, JP;
NGK SPARK PLUG CO., LTD., Nagoya-shi, JP;
Abstract
A spark plug includes a metal shell, an insulator, a center electrode, and a ground electrode. At least one of the center electrode and the ground electrode includes a projection having a columnar shape. The projection projects toward the other of the center electrode and the ground electrode and forms the discharge gap. A portion of a side surface of the projection has a recess. A melted portion is formed by melting the noble metal tip and an electrode base material. The recess is formed in the melted portion. When D is a depth of the recess from a side surface of the noble metal tip and R is a diameter of the noble metal tip, 0.05 mm≦D≦0.3×R is satisfied.