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:
Sep. 21, 2004
Filed:
Jul. 03, 2002
Kazuhiko Tanaka, Kuwana, JP;
Denso Corporation, , JP;
Abstract
A fabrication method of a metal shell to be installed on a park plug is provided which is made up of a small-diameter portion, a large-diameter portion, and a wrapping portion. The wrapping portion is to be wrapped by staking about the spark plug to achieve installation of the metal shell on the spark plug. The method comprises pressing a workpiece with a punch to shape the wrapping portion of the metal shell in a first cold forging process and processing the workpiece to shape the small-diameter portion of the metal shell in a second cold forging process different from the first cold forging process. This produces the metal shell which is less susceptible to cracks when installed on the spark plug and has an increased service life.