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:
Dec. 29, 2015
Filed:
Jul. 16, 2013
Ngk Spark Plug Co., Ltd., Nagoya, JP;
Masahiro Nishida, Konan, JP;
Tomoaki Kato, Nagoya, JP;
Keiji Ozeki, Konan, JP;
Naoyuki Mukouyama, Nisshin, JP;
Tsutomu Kobayashi, Inazawa, JP;
NGK SPARK PLUG CO., LTD., Nagoya, JP;
Abstract
A spark plug includes an insulator including an axial hole and having an outer periphery with a tapered outer face; a metal shell having a thread portion and a tapered inner face; and a circular packing sandwiched between the tapered outer face of the insulator and the tapered inner face of the metal shell. On at least one cross section including the axis, (A/B)≧3.1, B≧0.25, and (A+B)≦2.0 are satisfied, where A represents a length of (a difference between an effective diameter of the thread portion and an inner diameter at a rear end of the tapered inner face)/2, and B represents a length of (a difference between the inner diameter at the rear end of the tapered inner face and an inner diameter at a front end of the tapered inner face)/2.