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. 16, 2003
Filed:
Jan. 18, 2001
Applicant:
Inventors:
Keiji Kanao, Chita-gun, JP;
Seiki Nakagawa, Takahama, JP;
Assignee:
Denso Corporation, Kariya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01T 1/320 ;
U.S. Cl.
CPC ...
H01T 1/320 ;
Abstract
A spark plug having a tip composed of an iridium alloy essentially consisting of iridium is resistance welded through a relieving layer to a front end of a center electrode having an iron-based alloy and a facing portion of a ground electrode and wherein the material of the relieving layer has a coefficient of linear expansion between the iridium alloy and the iron-based alloy and has a Young's modulus of elasticity smaller than that of the two alloys.