Method and apparatus for forming a can end

Claim 1

Apparatus for forming a container end closure having a curled flange adapted to be double seamed to a container body, said apparatus comprising an upper die assembly and a lower die assembly mounted for reciprocable movement between an open and closed position, said upper die assembly having an axial punch, said lower die assembly having an axial anvil, an annular punch on said upper die assembly and a coacting cutting ring on said second die assembly for severing a disk blank from a sheet metal strip, said punch and anvil having complementary center opposing profiles including means for grasping and forming a center portion of the blank therebetween during the closing portion operation of said means, an upper drawing ring disposed between said annular punch and said axial punch, and a lower drawing ring disposed between said cutting ring and said anvil, groove means on said cutting ring coacting with said lower drawing ring for forming a peripheral flange on said disk blank when said die assemblies move to said closed position, said upper drawing ring having a circumferential groove including an inwardly contoured surface at the upper end thereof for curling said flange inwardly when said die assemblies move to said open position to form a curl about the periphery of said disk accompanied by simultaneous separating movement of said means to an open position and releasing said center portion whereby during curling said blank is grasped solely about its periphery by said lower drawing ring and said axial punch.

Claim 5

The method of forming an end closure which comprises severing a blank from a strip of sheet metal between a pair of die assemblies, clamping the center portion of said blank by die members and clamping the peripheral portion of the blank by a die element and one of said die members of said assemblies and forming a Semi-curled peripheral flange on said blank between said one of the die members and element as they move to a closed position, and releasing said center portion from between the die members and while holding said blank between said one die member and element only at said peripheral portion turning the edge of the semi-curled flange by engaging another die element therewith to form an inwardly directed curl as said die assemblies move to an open position.

Claim 6

The method of forming an end closure which comprises severing a blank from a strip of sheet metal between a pair of die assemblies, clamping the center portion of said blank by die members and clamping the peripheral portion of the blank by a die element and one of said die members of said assemblies and forming a Semi-curled peripheral flange on said blank between said one of the die members and element as they move to a closed position, and releasing said center portion from between the die members and while holding said blank between said one die member and element only at said peripheral portion turning the edge of the semi-curled flange by engaging another die element therewith to form an inwardly directed curl as said die assemblies move to an open position.