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. 02, 2013
Filed:
Dec. 21, 2011
Kenji Nunome, Nagoya, JP;
Kenji Nunome, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A spark plug includes a tubular metallic shell; a tubular insulator in the tubular metallic shell located at a front end of the metallic shell and having an axial hole extending in the axial direction; and a center electrode inserted into the axial hole. The center electrode has a space-forming portion which forms, in cooperation with a wall surface of the axial hole, an annular space open frontward in the axial direction, and a main body portion extending rearward from the rear end of the space-forming portion. The thickness of the insulator is 0.6 mm or less as measured on a cross section and contains the front end of the metallic shell. The axial distance between the boundary portion and the front end of the metallic shell is 0.4 mm or greater, where the boundary portion is formed between the space-forming portion and the main body portion.