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:
Jan. 09, 2001
Filed:
May. 14, 1999
Toru Moriya, Kasugai, JP;
NGK Spark Plug Co., Ltd., Nagoya, JP;
Abstract
A spark plug (,) has an outer tube member (,) that covers the outer peripheral surface of the projecting part (,) of an insulator (,) beyond a metallic shell (,), with its front end being coupled to the metallic shell (,). A hexagonal tool engaging portion (,) is formed in the rear end portion of the outer tube member (,). No tool engaging hexagonal portion is formed in the metallic shell (,). Accordingly, even if a plug hole (PH) of a smaller diameter is formed, the outside diameter of the insulator (,) need not be reduced accordingly since the heretofore required hexagonal portion is eliminated. As a result, the mechanical strength and withstand voltage of the insulator (,) can be ensured at adequately high levels.