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. 12, 2011
Filed:
Dec. 04, 2009
Mai Nakamura, Inazawa, JP;
Akira Suzuki, Nagoya, JP;
Mai Nakamura, Inazawa, JP;
Akira Suzuki, Nagoya, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A spark plug including an insulator and a metallic shell having an outer surface and an inner surface. The outer surface has a taper portion which comes into contact with a peripheral region around a mounting hole of an internal combustion engine, a tool engagement portion, and a trunk portion formed between the tool engagement portion and the taper portion. The inner surface has an annular step portion projecting toward the insulator and an internal trunk portion extending from the base of the step portion toward the rear end of the metallic shell. When the insulator and the metallic shell are fixed to each other by one of either cold and hot crimping, the projected area of the taper portion is at least two times or at least 1.5 times that of the step portion, respectively.