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:
Jul. 18, 2017
Filed:
Mar. 16, 2016
Ngk Spark Plug Co., Ltd., Nagoya-shi, Aichi, JP;
NGK SPARK PLUG CO., LTD., Nagoya-shi, Aichi, JP;
Abstract
A spark plug having a resistor disposed within a through hole of an insulator and between a center electrode and a metal terminal so as to be spaced apart from the center electrode in a direction of an axial line; and a conductive glass seal layer provided between the resistor and the center electrode and electrically connecting the resistor and the center electrode to each other, the conductive glass seal layer has a diameter of 3.9 mm or less, and a joined surface of the conductive glass seal layer and the resistor has a convex shape toward the center electrode side. A length α from a rear end to a front end of the joined surface and a maximum length β of the conductive glass seal layer in the direction of the axial line meets a relation of α/β≧0.4.