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:
Nov. 15, 2016
Filed:
Mar. 26, 2012
Jiro Kyuno, Kiyosu, JP;
Keiji Ozeki, Konan, JP;
Tomoaki Kato, Nagoya, JP;
NGK SPARK PLUG CO., LTD., Nagoya, JP;
Abstract
A method for manufacturing a spark plug includes an assembling step of assembling an insulator into a metallic shell by insertion of the insulator into the metallic shell from an axially rear end opening portion of the metallic shell. The assembling step includes a displacement restricting step of restricting a relative positional displacement between the metallic shell and the insulator in a radial direction intersecting with the axial direction so as to reduce eccentricity between the axis of the metallic shell and the axis of the insulator to a predetermined value or less, while allowing a relative positional displacement between the metallic shell and the insulator in the axial direction. In the assembling step, whether or not the insulator is cracked in the assembling step is judged by detecting acoustic emission from the insulator.