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. 01, 2016
Filed:
Aug. 08, 2014
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Haruki Yoshida, Tajimi, JP;
Takamitsu Mizuno, Hashima, JP;
Masaaki Kumagai, Aichi, JP;
Jumpei Kita, Nagoya, JP;
Yoshitomo Iwasaki, Komaki, JP;
Toshitaka Honda, Nagoya, JP;
NGK SPARK PLUG CO., LTD., Aichi, JP;
Abstract
A spark plug includes an insulator having an axial hole, a center electrode inserted into a forward portion of the axial hole, a terminal electrode inserted into a rear portion of the axial hole, and an interelectrode insert which contains glass and electrically conductive carbon and is disposed in the axial hole between the center electrode and the terminal electrode. The interelectrode insert has a resistance of 1.0 kΩ to 3.0 kΩ, and the interelectrode insert has a carbon content of 1.5% by mass to 4.0% by mass at a forward portion located forward of a center point between the rear end of the center electrode and the forward end of the terminal electrode. Furthermore, the forward portion is lower in resistance than a rear portion of the interelectrode insert located rearward of the center point.