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. 11, 2007
Filed:
Mar. 21, 2007
Katsunori Hagiwara, Mie, JP;
Satoshi Nagasawa, Nagoya, JP;
Wataru Matutani, Nagoya, JP;
Toru Nakamura, Nagoya, JP;
Tomoaki Kato, Nagoya, JP;
Yuichi Yamada, Aichi, JP;
Katsunori Hagiwara, Mie, JP;
Satoshi Nagasawa, Nagoya, JP;
Wataru Matutani, Nagoya, JP;
Toru Nakamura, Nagoya, JP;
Tomoaki Kato, Nagoya, JP;
Yuichi Yamada, Aichi, 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 arranged on a front end of the electrical insulator. The ground electrode has an opening defining portion defining an opening for communication between the cavity and the outside of the spark plug. The opening defining portion is located radially inside of or in contact with a first imaginary circular conical surface where the first imaginary circular conical surface has an axis coinciding with an axis of the spark plug and a vertex angle of 120° opening toward a front end of the spark plug and passing through a front edge of the insulator axial hole.