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:
May. 07, 1996
Filed:
Jun. 03, 1994
Kazumi Kawamura, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
In a spark plug for a gas engine including a ground electrode (4) whose front end is to be placed in a combustion chamber of a gas engine which is driven by gaseous fuel, a metallic shell (3) enclosing a center electrode (5) which has a noble metal tip (18) superior in spark-erosion resistance at a firing portion in which a spark discharge occurs against the ground electrode (4). A resistor (10) is provided within the spark plug or a spark plug cap so as to be included in a spark plug voltage circuit which applies a high voltage to the center electrode. It is preferable that the noble metal tip (18) has a diameter in a range of 0.5.about.1.5 mm, and that the resistor has an electrical resistance greater than or equal to 50 k.OMEGA..