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. 18, 2014
Filed:
Aug. 18, 2011
Mai Nakamura, Inazawa, JP;
Jiro Kyuno, Kiyosu, JP;
Tomoaki Kato, Nagoya, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A spark plug includes a ceramic insulator having a tapered rear end stepped portion whose diameter decreases from front to rear and a metal shell having a crimp portion which crimps the rear end stepped portion from the rear end. An area defined by an outer edge of the rear end stepped portion and an inner edge of the crimp portion is 5-25 mmwhen the spark plug is projected on a plane perpendicular to an axial line. An angle formed by a tapered surface of the rear end stepped portion and a plane perpendicular to the axial line is 20-60 degrees. A distance along the axial line from a front end of a proximal portion of the crimp portion to a frontmost position of a contact portion between an inner surface of the crimp and the rear end stepped portion is 0.4-1.8 mm.