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:
Oct. 20, 2015
Filed:
Sep. 03, 2013
Ngk Spark Plug Co., Ltd., Nagoya, JP;
Jiro Kyuno, Kiyosu, JP;
NGK SPARK PLUG CO., LTD., Nagoya, JP;
Abstract
A spark plug includes a tubular insulator and a tubular metal shell secured to an outer peripheral surface of the insulator by crimping. The tubular metal shell includes: an inner peripheral surface where powder for sealing is filled between the outer peripheral surface and the inner peripheral surface; a tool engagement portion overhanging in a polygonal shape; and a crimped lid disposed at an end portion of the metal shell coupled to the tool engagement portion, the end portion being bent toward the outer peripheral surface of the insulator by crimping. A relationship between a length L and a thickness t satisfies 2.50≦L/t≦3.10, the length L being a length along a shape of the crimped lid from the tool engagement portion to the insulator in a planar surface that passes through the axis, the thickness t being a thickness at an intermediate portion of the crimped lid.