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:
Mar. 26, 1996
Filed:
Aug. 16, 1994
Akio Katoh, Nishio, JP;
Kozo Takamura, Nagoya, JP;
Nippondenso Co., Ltd., Kariya, JP;
Abstract
According to the present invention, a spark plug for an internal combustion engine includes a center electrode, a ground electrode so as to form a spark gap with the center electrode, and a tip electrode composed of a material having a superior consumable resistance as compared to the center electrode and disposed on an end face of the center electrode so as to form a spark gap with the ground electrode. An axial length of the discharge portion of the ground electrode where spark discharge occurs is substantially larger than an axial length of the tip electrode where spark discharge occurs. When used for an internal combustion engine, a spark discharge is mainly generated between the peripheral surface of the center electrode and the ground electrode during early operation. Consequently, as the center electrode has been consumed, the spark discharge is mainly generated between the tip electrode and the ground electrode. Therefore, the frequency of the spark discharge with the center electrode is lowered, and a low required voltage is maintained.