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:
Apr. 10, 2001
Filed:
Dec. 09, 1998
Applicant:
Inventors:
Nobuo Abe, Yokkaichi, JP;
Yasushi Kawashima, Inabe-gun, JP;
Assignee:
Denso Corporation, , JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
H01T 1/320 ; H01T 1/322 ; H01T 1/334 ; H01T 1/336 ; H01T 2/102 ;
U.S. Cl.
CPC ...
H01T 1/320 ; H01T 1/322 ; H01T 1/334 ; H01T 1/336 ; H01T 2/102 ;
Abstract
A spark plug defines a spark gap G in a range of 0.2 mm≦G<0.4 mm, between a noble metal chip disposed on a central electrode and an earth electrode. The noble metal chip has a groove portion facing the earth electrode so that a space, which is larger than a sphere having a diameter equal to or larger than 0.4 mm, is provided in the spark gap G. As a result, a flame core having a diameter equal to or larger than 0.4 mm can be held in the space not to be quenched, resulting in high ignition property of the spark plug.