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. 19, 2006
Filed:
Dec. 10, 2003
Hitoshi Morita, Aichi-ken, JP;
Shinichi Okabe, Aichi-ken, JP;
Masamichi Shibata, Toyota, JP;
Tsunenobu Hori, Kariya, JP;
Hitoshi Morita, Aichi-ken, JP;
Shinichi Okabe, Aichi-ken, JP;
Masamichi Shibata, Toyota, JP;
Tsunenobu Hori, Kariya, JP;
Denso Corporation, , JP;
Nippon Soken, Inc., , JP;
Abstract
A spark plug is composed of a main metal fitting having a cylindrical structure, an insulator disposed inside the cylindrical main metal fitting, a center electrode fitted in the insulator in a manner that a front end portion of the center electrode projects outward over one end of the insulator, and a grounding electrode mounted to the main metal fitting and having one end portion opposing to the front end portion of the center electrode through a discharge gap therebetween. The front end portion of the center electrode includes a conical portion having a tapered surface having a taper angle of less than 80°, and a columnar portion formed to a top end portion of the conical portion so as to have a diameter in a range of 0.4 mm to 0.8 mm.