System for production of metal tear tabs

摘要

This relates to the handling of thin soft temper material during the feeding thereof and in formation of such material into individual components in a punch press. Most particularly, a pull tab formed of a plastics material-aluminum foil laminate is being formed. In order to control the movement of the stock through the punch press, the stock is longitudinally stiffened by the formation of longitudinal ribs therein. The ribs are preferably formed by the stock feeding mechanism. The work product is blanked and formed substantially in its entirety in regions of the stock outside of the stiffening rib areas and prior to the final severing of the work product from the stock, the stiffening ribs are flattened. In the separation of the work product from the stock, there is material removal in a punching operation along the areas previously containing the stiffening ribs. Feeding of the stock is accomplished by a rotary cam which permits feeding of the stock at all times while the punch elements are disengaged from the stock, thus providing for a longer feed time. The feed may be selectively less than that provided by the cam by utilizing pivotally mounted feed dogs and a stop which effects pivoting of the dogs and the releasing of the stock while the feed mechanism is still advancing.