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:
May. 29, 2018
Filed:
Nov. 22, 2017
Ngk Spark Plug Co., Ltd., Nagoya, Aichi, JP;
Tomonori Kanemaru, Kasugai, JP;
NGK SPARK PLUG CO., LTD., Nagoya, JP;
Abstract
A cylindrical metal shell extending in an axis direction has a seat portion projecting radially outward, and an annular gasket is disposed so as to oppose a front end surface of the seat portion. A value G/S obtained by dividing an arithmetic average roughness G of a first surface, of the gasket, which comes into contact with the front end surface of the seat portion by an arithmetic average roughness S of the front end surface of the seat portion satisfies 0.5≤G/S≤2.0. The arithmetic average roughness G is not more than 0.16 μm, and an average of an area of a second surface on a back side of the first surface and an area of the first surface is not more than 280 mm.