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:
Feb. 16, 2010
Filed:
Mar. 29, 2007
Iwao Kunitomo, Nagoya, JP;
Yoshihiro Matsubara, Yokkaichi, JP;
Hironobu Mizutani, Aichi, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A spark plug including: a cylindrical insulator having an axial hole extending through the insulator in an axial direction; a center electrode inserted in the axial hole; a metal shell provided around an outer periphery of the insulator and having a leading end surface, from which a leading end surface of the insulator protrudes; a ground electrode having a base end bonded to the leading end surface of the metal shell; and a noble metal tip disposed on a distal end of the ground electrode, an end of the noble metal tip protruding toward the center electrode in a radial direction, wherein: the spark plug forming a spark discharge path upon application of a discharging voltage between the protruding end of the noble metal tip and an end of the center electrode, the spark discharge path including an aerial discharge gap between a part of the protruding end of the noble metal tip and a part of the end of the insulator and a surface-creeping discharge path beginning at a part of the end of the insulator and a part of the center electrode and extending along the end surface of the insulator; and the noble metal tip protruding from the leading end of the ground electrode by a protruding length of more than 0.2 mm.