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. 23, 1993
Filed:
Feb. 27, 1991
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
In a multi-gap type spark plug for an internal combustion engine, the spark plug has a cylindrical metallic shell into which a tubular ceramic insulator is enclosed. The insulator has a tapered front leg portion, a front end of which extends beyond that of the metallic shell. A center electrode is enclosed into the insulator, having at a front end thereof, a filing tip extending beyond that of the insulator. A plurality of L-shaped outer electrodes each having a vertical piece and lateral piece, the vertical piece depending from the front end of the metallic shell to surround the front end of the insulator, while the lateral piece having an inner surface arranged in parallel with a front end surface of the insulator, and having an end tip terminated to oppose an outer surface of the firing tip through a spark gap established therebetween. A vertical distance between the front end surface of the insulator and the inner surface of the lateral piece of each outer electrode is determined to be within a dimension ranging from 0.3 mm to 1.2 mm.