초록 ▼

The disclosure relates to a novel shell such as used in the manufacture of can ends, and to a method and tools for making such a shell. A non-circular blank having rounded corners is cut from thin metal. The blank is oblong in a direction transverse to the grain of the metal. A first set of tools se

The disclosure relates to a novel shell such as used in the manufacture of can ends, and to a method and tools for making such a shell. A non-circular blank having rounded corners is cut from thin metal. The blank is oblong in a direction transverse to the grain of the metal. A first set of tools separates the blanks and forms a substantially flat central panel and an upward-extending chuck wall about the edge of the panel to produce a partially formed shell. The junction area between the panel and the chuck wall has a relatively large radius of curvature at this time. A second set of tools forms in the blank a lip extending outward from the upper end of the chuck wall and generally parallel to the panel; then the panel and the chuck wall are separately gripped, followed by relative movement between the panel and the chuck wall while wrapping the junction area around a forming punch to form a panel wall in the junction area extending upward from the inner part of the chuck wall. Then the lip is formed into a curl edge section which ends in an inner curl diameter that is round and concentric with the chuck wall, and has progressively lesser radii of curvature from upper end of the chuck wall to the inner curl diameter. The resulting shell is characterized by a curl diameter being round and concentric with the chuck wall and essentially uniformly spaced therefrom, and by having an essentially constant thickness throughout the central panel, the panel wall and chuck wall and the curved section therebetween.

대표청구항 ▼

A method of forming a container end panel from a blank of material comprising the steps of: (a) engaging a central section of the blank between a pressure pad and a punch center and wiping a radially outboard section of the blank over said punch center by moving a die form ring and a concentrically

A method of forming a container end panel from a blank of material comprising the steps of: (a) engaging a central section of the blank between a pressure pad and a punch center and wiping a radially outboard section of the blank over said punch center by moving a die form ring and a concentrically disposed draw ring relative to the punch center, thereby forming a cupshaped member having a formed bottom panel and an annular peripheral section; and (b) holding a portion of said peripheral section and forming a countersink radius adjacent said bottom panel by pulling material from said peripheral section.