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:
Aug. 22, 2017
Filed:
Aug. 20, 2014
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Shinya Mitsuda, Inuyama, JP;
Yuichi Yamada, Aichi, JP;
NGK SPARK PLUG CO., LTD., Nagoya-shi, Aichi, JP;
Abstract
A spark plug includes an insulator having a through hole formed in the direction of an axis, a rod-shaped center electrode inserted in the through hole and extending in the direction of the axis, a metal shell disposed around an outer circumference of the insulator, and a ground electrode electrically conducted with the metal shell and adapted to define a gap between the ground electrode and the center electrode. A front end part of the insulator has a front end surface, an outer circumferential surface and a curved surface region formed between the front end surface and the outer circumferential surface. In a cross section including the axis, a front end of an inner circumferential surface of the metal shell faces the curved surface region in a direction perpendicular to the axis. The curved surface region has a curvature radius of 0.2 mm to 0.8 mm.