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:
Dec. 03, 2002
Filed:
Mar. 20, 2000
Hideki Teramura, Mie, JP;
Wataru Matsutani, Nagoya, JP;
NGK Spark Plug Co., Ltd., Aichi, JP;
Abstract
A gasket for a threaded element such as a spark plug to be screwed into a threaded hole of a support such as a cylinder head is provided. The threaded element has a threaded portion and an annular seat portion. The gasket is installed on the threaded element and compressed between the seat portion and an outer surface of the support around a threaded hole, when the threaded element is screwed into the threaded hole, to provide a seal between the threaded portion and the threaded hole. The gasket is formed from an annular sheet metal and in the form of an annular strip of a cross section including a plurality of bent portions. The cross section is made by a plane including a center axis of the gasket and of a such a bent shape as to enable an imaginary reference line which is located on the above described plane and parallel with the center axis, to cross at least three portions of the cross section. The initial axial size of the gasket, i.e., the height of the gasket before the gasket is compressed, is at least 2.5 mm. When pressure within a proper pressure range is applied to the gasket, i.e., within a proper pressure range from 6 to 12 kgf/mm , a variation &Dgr;&agr; of compressive deformation &agr; of the gasket corresponding to advance or axial movement of the threaded element by at least 0.5 pitch of the thread, i.e., corresponding to movement of the threaded element resulting from at least 0.5 turn is retained.