Method and apparatus for forming a can shell

摘要

A sheet of metal is blanked by an annular die to form a disk, and a peripheral portion of the disk is gripped between the blank die and a lower pressure sleeve. The peripheral portion is shifted downwardly relative to a center portion of the disk engaged by a center panel punch to form a center panel portion and a panel wall portion connected by a generally frusto-conical inverted chuck wall portion to the peripheral wall portion. The center panel portion and the panel wall portion are engaged by a die center having a projecting lip with a small countersink radius. An inner part of the peripheral wall portion is gripped between a die core ring and an upper pressure sleeve to define a crown portion, and an outer part of the peripheral portion of the disk is formed by the blank die and the die core ring into a depending lip portion. The center panel portion is shifted downwardly by the die center and panel punch in a direction to reverse form the inverted chuck wall portion into a chuck wall portion and a countersink portion by laying the metal around the countersink radius on the die center. After an overstroke operation, the completed shell is removed with the use of air jets within the panel punch and a vent passage within the center die.