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. 06, 2011
Filed:
Mar. 19, 2007
Kazuyoshi Torii, Aichi, JP;
Kazumasa Yoshida, Nagoya, JP;
Wataru Matsutani, Nagoya, JP;
NGK Spark Plug Co., Ltd., , JP;
Abstract
A spark plugcomprised of a metal shell, an insulator, a center electrodeand a ground electrode. A rear-end face of the ground electrodeis welded to a front-end face of the metal shell, and a bent portionlocated at the intermediated position in the longitudinal direction is bent toward the center of the spark plug. The ground electrodeassumes a circular-shape with a diameter of 2 mm or less whereby an inflow of an air-fuel mixture is not disturbed even when the air-fuel mixture directly flows into a back face of the ground electrode. The ground electrodeis comprised of an outer layerA made of a nickel alloy and an inner layerB made of pure copper with an excellent thermal conductivity, in which a ratio of a cross-sectional area of the inner layerB to the entire cross-sectional area of the ground electrodeis 10% or more to 35% or less. Thus, the spark plugwhich is excellent in heat sinking ability and can prevent a spring back phenomenon due to a difference in a coefficient of thermal expansion.