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. 26, 2007
Filed:
Aug. 30, 2005
Nobuo Abe, Yokkaichi, JP;
Yasushi Kawashima, Mie-ken, JP;
Tsunetoshi Goto, Handa, JP;
DENSO Corporation, , JP;
Abstract
A spark plug is provided which is designed to be compact without sacrificing a mechanical strength of a porcelain insulator. The spark plug includes a metal shell having a base end and a top end. The porcelain insulator is made of a hollow cylinder which includes a body and an insulator head. The body is retained within the metal shell. The insulator head extends from the base end of the metal shell in a lengthwise direction of the porcelain insulator and has a length made up of a major body leading to the body of the porcelain insulator and an end portion lying far away from the body. The major body has an outer diameter D, an inner diameter D, and a section modulus Z at a smallest-outer diameter portion thereof which meet relations of 7.1 mm≦D≦8.8 mm, D≧2.8 mm, and Z≧33 mm.