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. 20, 2001
Filed:
Feb. 10, 1999
Toru Moriya, Aichi, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A distributorless ignition system is provided which includes an ignition coil for firing a pair of first and second spark plugs at the same time. The ignition system includes a changeover switch which, when assuming one operating position, causes the first spark plug to produce negative polarity spark and the second spark plug to produce positive polarity spark and, when assuming another operating position, causes the first spark plug to produce positive polarity spark and the second spark plug to produce negative polarity spark. The operating position of changeover switch is changed every time the number of sparks produced by each of the first and second spark plugs becomes two. By this, the number of negative polarity sparks and the number of positive polarity sparks produced by each of the first and second spark plugs on compression stroke at its corresponding cylinder over a long period of time are the same. This enables the center electrode and ground electrode of each of the first and second spark plugs to wear away equally. An ignition method is also provided.