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:
Aug. 18, 1981
Filed:
Aug. 13, 1979
Kashiwa Murayama, Fujisawa, JP;
Japan Crown Cork Co., Ltd., Tokyo, JP;
Abstract
A method of producing an easily openable container closure which has (1) a shell of with unitary structure including a top and cylindrical skirt, the top having an annular top surface portion leading to the upper end of the skirt and a pull ring connected to a part of the inner peripheral edge of the annular top surface portion by a linking piece, and the annular top surface portion and the skirt having a pair of breaking weakened lines extending from both side edges of the linking piece. A set of lance slits is formed in a metal blank, and a pair of weakening lines is formed spaced from each other at a predetermined distance in the circumferential direction and extending over a predetermined distance from near the lance slits toward the center of a circular portion located inwardly of the lance slits. An opening is punched out of the circular portion and the circular portion located inwardly of the lance slits is drawn to form a shell having a circular top with said opening therein and a substantially cylindrical skirt continuous therewith. A slit is formed along said opening spaced a predetermined distance outwardly from the opening. The portion between the opening and the slit is then bent to form a pull ring, and the thus formed shell is separated from the metal blank.