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:
Jul. 01, 2003
Filed:
Oct. 28, 2002
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A battery case ( ) is formed such that a thickness (t ) of a side wall ( ) with respect to a thickness (t ) of a bottom wall ( ) satisfies t =&agr;t (&agr;=0.2 to 0.7) undergoing an ironing step using ironing dies ( , and ) aligned in multiple stages, and that an inside face of the side wall is made to have a rough surface having average surface roughness of 0.2 &mgr;m to 2.0 &mgr;m by undergoing a drawing step after the ironing step. A manufacturing method of the battery case includes a first step of manufacturing a battery case element ( ) by applying the DI processing to a cup-shaped intermediate product ( ), and a second step of manufacturing a battery case by reducing an outside diameter to a predetermined outside diameter (r) without changing a thickness of a side wall by applying drawing processing to the battery case element by drawing dies ( and ) aligned in multiple stages.