公开(公告)号：US3741141A

公开(公告)日：1973-06-26

申请号：US3741141D

申请日：1971-09-20

Applicant: ALUMINUM CO OF AMERICA

Inventor： DIEKHOFF H ,  SCHRECKER H

IPC: B21D39/03 ,  B21D51/38 ,  B21D51/26

CPC classification number: B21D51/383 ,  B65D17/28

Abstract: Apparatus for fabricating a tab element having an opening for joinder to a container wall including a female die having an elongated recess and an outwardly disposed annular tab engaging surface. A male die having an upwardly directed boss and a surrounding annular tab supporting surface. The male die having a concave transverse wall connecting the die boss with the annular tab supporting surface. Aligning the tab opening with the die elements and establishing relative closing movement between the dies produces compressive reforming of the opening defining portion of the tab element to provide a convexly curved portion corresponding in curvature to the male die concave transverse wall. A method of reforming an opening defining wall in a tab element to provide a continuous wall which diverges from the upper tab surface to the lower tab surface by compressively reforming the continuous wall. A container wall having a removable sector with a tab element secured thereto by means of an integral rivet including a wall panel having a hollow integral rivet provided with a transverse end wall and a peripheral wall. A tab element having an attachment opening defined by a continuous wall and the rivet extending through the tab element with the continuous opening defining wall in contact with the peripheral rivet wall. The opening defining wall having a lower inwardly convexly curved portion in surface to surface contact with a portion of the peripheral rivet wall having an outwardly concave configuration.