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:
Sep. 28, 2004
Filed:
Oct. 30, 2002
Yoshihisa Sugiyama, Gifu, JP;
Yoshitaka Sugiura, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
In a spark plug ( ), at least one side face of the ground electrode ( ) is made of an electrode base material comprising an Ni alloy containing 21-25% by mass of Cr, 1-2% by mass of Al, 7-20% by mass of Fe and 58-71% by mass of Ni. The noble metal wear resistant portion ( ) is joined to the electrode base material via a welding portion (W). When the linear expansion coefficients at 800 K of the noble metal constituting the noble metal wear resistant portion ( ) and the electrode base material are represented by &agr;1 and &agr;2, respectively, &Dgr;&agr;≡&agr;2−&agr;1 is adjusted to be 4.55×10 /K or less. The outer diameter of the noble material wear resistant portion ( ) is set from 0.6 mm to 1.5 mm.