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:
Apr. 11, 2017
Filed:
Oct. 10, 2014
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
Tsutomu Kobayashi, Inazawa, JP;
Keiji Ozeki, Konan, JP;
NGK SPARK PLUG CO., LTD., Aichi, JP;
Abstract
A packing between an insulator and a metal shell of a spark plug. A length between a first position of a contact portion of the packing and the insulator and a second position of a contact portion of the packing and the insulator parallel to an axial line direction is set as a first length. In the case where a load perpendicular to the axial line direction is applied to the second position, a ratio of stress at a surface position that is a position on a surface of the insulator to stress at the first position is set as a stress ratio. In a range of the surface position where the stress ratio is 0.8 or more to 1.15 or less, a length in a continuous range from the first position toward a front end side parallel to the axial line direction is set as a second length. A ratio of the second length to the first length is 0.7 or more.