Patent ID: 6230538
Filing Date: 2001-05-15
Classification: B21D

Abstract:
A method of drawing a workpiece into a battery case having relatively lone side walls and a relatively small diameter, the method comprising the steps of:a. providing a plurality of drawing turrets for continuously partly drawing the battery cases, and transfer turrets positioned to pass workpieces or partly formed battery cases to subsequent drawing turrets, each of the drawing turrets comprising a continuously rotating support plate carrying a plurality of tool sets each including a punch and die and a centering mechanism, the plurality of tool sets of a first of the drawing turrets being of a larger diameter than the other pluralities of tool sets, and the plurality of tool sets of each successive drawing turret being of progressively smaller diameter;b. loading the workpiece onto the continuously rotating support plate of a first drawing turret;c. centering the workpiece over one of the dies with the centering mechanism;d. drawing the workpiece with the punch associated with said one of the dies as the first drawing turret rotates, the punch operable between a retracted position, in which the punch is spaced from the die, and an extended position, in which the punch extends at least partially through the die, the punch operating from the retracted position by rotation of the first drawing turret to the extended position to draw the workpiece into the battery case;e. removing the case from the die after drawing;f. depositing the case onto a transfer turret for transfer to a successive drawing turret to ultimately reduce the diameter and increase the length of the case to battery size; andg. repeating the loading, centering, drawing, removing and depositing steps with a new workpiece for each tool set as the first drawing turret rotates.