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. 24, 2015
Filed:
Sep. 05, 2014
Ngk Spark Plug Co., Ltd., Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A spark plug includes an insulator, a terminal electrode, a center electrode, a resistor, and a glass seal layer. The terminal electrode has: a recess part opened to the front end side and having a depth in a center axis direction of the terminal electrode; and a flat part neighboring the recess part at its outer circumference side. The relationship 0.52≦B/A≦0.91 is satisfied, wherein A (mm) represents an area of a region surrounded by an outline of an outer circumference surface of the terminal electrode, and B (mm) which represents an area of a region of the terminal electrode surrounded by an outline of an inner surface of the recess part, in a cross section orthogonal to the center axis and located 0.1 mm away from a front end along the center axis to the rear end side.