Method and apparatus for forming container end shells

Apparatus for forming an end panel having a peripheral curl in a press having inner and outer rams comprising:

• a punch core and a punch shell reciprocally movably carried by the inner ram;
• a blank and draw die carried by a base and defining a first level;
• a die core carried by the base in opposed relationship to the punch core and defining a second level;
• inner and outer die core rings reciprocally movably mounted on the base in concentric relationship with said die core, said outer die core ring being in opposed relationship to the punch shell and having an outer curl groove formed therein;
• said punch shell being movable through the blank and draw die to form a cup-shaped blank and to releasably clamp an outer portion of said cup-shaped blank in the curl groove of the outer die ring to form an end shell having an elongated chuckwall by movement of said punch shell and outer die core ring beyond the second level;
• and
• said inner die core ring being adapted to clamp a portion of the chuckwall as the outer die core ring and punch shell draws the peripheral curl in the end shell upon reversing the direction of movement of said punch shell and outer die ring.

A method of forming an end shell having a peripheral curl for use on a container at a single station in a press from sheet material including the step of:

• cutting a blank from the sheet material at a first level;
• forming a chuckwall against inner and outer die core rings by drawing an outer portion of the blank over a die core at a second level by advancing a punch shell;
• applying a curl to a peripheral edge of the chuckwall prior to removal of the blank from the press by withdrawing the punch shell while simultaneously advancing the outer die core ring to move an outer peripheral portion of the chuckwall about a curl groove formed in an end of the outer die core ring;
• and
• discharging the end shell from the press at said second level.

A method of forming an end shell having an annular reinforcing rib for use on a container from sheet material including the step of:

• cutting a flat blank from the sheet material against a cut edge at a first level;
• forming a cup-shaped blank having a bottom panel and a sidewall by drawing the flat blank through a blank and draw die;
• clamping the bottom panel between a punch core and a die core at a second level;
• providing the punch core with a female die component defining an annular reinforcement groove;
• providing inner and outer concentric die core rings about the die core;
• trapping an outer portion of the cup-shaped blank between the outer die core ring and a punch shell;
• forming an end shell blank having an elongated chuckwall from the cup-shaped blank by advancing the punch shell and inner and outer die core rings below the second level;
• and
• reversing the direction of movement of the inner and outer die core rings and punch shell to push a portion of the end shell blank into the female die component free of any mating male die component to form the annular reinforcing rib on said end shell as the bottom panel remains clamped between the punch core and die core.