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:
Oct. 14, 2003
Filed:
May. 17, 2001
Hiroaki Kawamura, Yamaguchi-ken, JP;
Hiroaki Okamoto, Yamaguchi-ken, JP;
Kinji Saijyo, Yamaguchi-ken, JP;
Toyo Kohan Co., Ltd., Tokyo, JP;
Abstract
A safety device for a closed battery capable positively preventing a rupture due to a rapid internal pressure rise at over-packing and short-circuiting and being produced inexpensively, a positive electrode lid ( ) attached to one end of an outer covering can ( ) comprises a pressure receiving plate ( ) forming the innermost lid and connected to positive electrode ( ) of an electrode unit ( ) via positive electrode lead ( ), a shielding plate ( ) forming a middle lid and electrically connected to the pressure receiving plate ( ) via a center contact ( ), and a sealing plate ( ) forming the outermost lid and electrically connected to the shielding plate ( ). The center contact ( ) is formed of a projection ( ) having a first flat contact surface ( ) of the pressure receiving plate ( ) and a second flat contact surface ( ) of the shielding plate ( ), and a plurality of annular grooves ( ) are alternately provided around the second flat contact surface ( ) so as to face each other at 180° intervals, the annular grooves ( ) being covered with a metal foil ( ) to form valve membranes ( ).