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. 21, 1989
Filed:
Sep. 11, 1987
NGK Spark Plug Co. Ltd., Nagoya, JP;
Abstract
In a center electrode structure for spark plug including a tubular insulator, the inner side of which has a stepped shoulder to provide a diameter-reduced bore therein; a center electrode having a flange, and concentrically placed into the insulator with the flange engaging against the shoulder, and with one end being axially through the bore so as to be exposed to outside of the insulator; the center electrode having a highly heat conductive core of copper or copper-based alloy which is encased into an enclosure made of oxidation and heat resistant nickel-based alloy; and the core providing its overall outer surface with a thin oxidation layer, so that the core is clad with the enclosure through the oxidation layer by means of extrusion.