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:
Feb. 02, 1999
Filed:
Aug. 20, 1997
Junichi Kagawa, Nagoya, JP;
Wataru Matsutani, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A spark plug is provided having a center electrode disposed in a metallic shell through an insulator so that the front end of the center electrode forms a spark gap with an outer electrode. A platinum tip is secured to the outer electrode positioned to oppose the front end of the center electrode. The outer electrode is provided with a heat-conductive core metal cladded with a matrix metal which is made of a nickel-based alloy containing 10-20 wt. % chromium. The platinum tip is welded to the outer electrode to form a welded portion between the platinum tip and the outer electrode and the platinum tip is positioned to terminate slightly short of the core metal so that the distance between a circumferential edge of the welded portion and a front end of the core metal is in the range 0.0 mm-2.0 mm measured lengthwise along direction the outer electrode.