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:
Feb. 12, 2008
Filed:
Mar. 21, 2007
Katsunori Hagiwara, Mie, JP;
Satoshi Nagasawa, Nagoya, JP;
Wataru Matutani, Nagoya, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A plasma-jet spark plug includes a metal shell, an electrical insulator retained in the metal shell, a center electrode held in an axial hole of the electrical insulator to define a cavity by a front end face of the center electrode and an inner circumferential surface of the insulator axial hole and a ground electrode fitted to a front end face of the electrical insulator and formed with an opening for communication between the cavity and the outside of the spark plug and satisfies the following dimensional relationships:d≦D≦3d;0.5 mm≦d≦1.5 mm;L1≦1.5 mm;2d≦L2≦3.5 mm; and2+{()/2}≦3.5 mmwhere D is a diameter of the ground electrode opening; L1 is a thickness of the ground electrode; d is a diameter of the cavity; and L2 is a depth of the cavity.