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:
Jun. 29, 2021
Filed:
Mar. 31, 2020
Applicant:
Ngk Spark Plug Co., Ltd., Nagoya, JP;
Inventor:
Susumu Imai, Nagoya, JP;
Assignee:
NGK SPARK PLUG CO., LTD., Nagoya, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
H01T 13/08 (2006.01);
U.S. Cl.
CPC ...
H01T 13/08 (2013.01);
Abstract
A spark plug includes a tubular metallic shell having an attachment screw portion having an external thread, an insulator disposed inside the metallic shell and having an axial hole, and a center electrode disposed in the axial hole. The attachment screw portion has a pitch diameter local maximum portion at which the external thread has a locally maximum pitch diameter. The pitch diameter local maximum portion is located on the forward end side of a rear end of the center electrode in a direction along an axial line of the metallic shell.