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:
Oct. 07, 2014
Filed:
Jun. 14, 2011
Hiroyuki Kameda, Nagakute, JP;
Daisuke Nakano, Kiyosu, JP;
Naofumi Yamamura, Nagoya, JP;
Daisuke Kasahara, Toyoake, JP;
Yoshikuni Sato, Nagoya, JP;
Hiroyuki Kameda, Nagakute, JP;
Daisuke Nakano, Kiyosu, JP;
Naofumi Yamamura, Nagoya, JP;
Daisuke Kasahara, Toyoake, JP;
Yoshikuni Sato, Nagoya, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
An ignition plug providing excellent ignition performance that can be maintained over a long period of time by restraining channeling. The ignition plug includes a ceramic insulator having an axial bore, a center electrode inserted into the axial bore, a metallic shell, and a ground electrode fixed to the metallic shell, and has a cavity defined by an inner circumferential surface of the axial bore and the forward end surface of the center electrode. The axial bore includes a first straight portion and a diameter-reducing portion. As viewed on a section which contains an axis (CL) of the ignition plug, a relational expression α≧10 is satisfied, where α (°) is an acute angle formed by a straight line orthogonal to the axis (CL) and the outline of the diameter-reducing portion.