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:
Jun. 23, 2009
Filed:
Mar. 04, 2005
Osamu Yoshimoto, Aichi, JP;
Wataru Matsutani, Aichi, JP;
Osamu Yoshimoto, Aichi, JP;
Wataru Matsutani, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A noble-metal chip () joined to at least either a center electrode or a ground electrode, the center and ground electrodes forming a spark discharge gap, and having a circumferential edge of its facing end surface () removed so as to form an edge-removed portion (). The edge-removal length is 0.01 mm or more and a ratio of the edge-removal length to a radius of the noble-metal chip is less than 0.3. The noble-metal chip is made of iridium or an alloy that contains iridium man amount of 70% by weight or more, and crystal grains constituting the noble-metal chip () extends in the axial direction. Also disclosed is a method for manufacturing the spark plug.