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:
Dec. 25, 2012
Filed:
Jul. 31, 2008
Ken Hanashi, Handa, JP;
Satoru Kadowaki, Mie-ken, JP;
Tsunenobu Hori, Kariya, JP;
Kenka Tsubota, Chiryu, JP;
Hirotaka Aida, Toyota, JP;
Hiroya Ishiguro, Kariya, JP;
Ken Hanashi, Handa, JP;
Satoru Kadowaki, Mie-ken, JP;
Tsunenobu Hori, Kariya, JP;
Kenka Tsubota, Chiryu, JP;
Hirotaka Aida, Toyota, JP;
Hiroya Ishiguro, Kariya, JP;
Denso Corporation, Kariya, JP;
Abstract
A spark plug for an internal-combustion engine comprises an attachment fitting, an insulator, a center electrodeand an earth electrode. While fixed to the attachment fitting, the earth electrodehas a convex partformed by projecting toward the center electrodea part of the opposed surface, which faces the center electrode, of the earth electrode and a concave partformed toward the opposed surfacefrom the earth electrode's back surfacewhich is the reverse side of the opposed surfaceof the earth electrode. The convex partis disposed so that the extension of a shaft center of the convex partmay pass through the area in which the concave partis formed. A relation of S>=s is realized when an area of an opening of the concave partis set to Sand an average cross-section area of a cross section of the convex partperpendicular to an axial direction of the spark plug is set to s.