Method and apparatus for die jam protection/anticipation and correction

摘要

A method and apparatus for protecting a die from damage due to material jams in material stamping equipment wherein feed material is stamped in a die and then advanced through the die by action of press feed rolls powered by a press feed roll drive motor. The position error of the press feed rolls or the torque of the press feed roll drive motor is monitored during the advance of the feed material through the die. The monitored position error of the press feed rolls or the monitored torque of the press feed roll drive motor is then compared to the expected position error of the press feed rolls or the expected torque of the press feed roll motor, respectively. The feed material is moved backwards to a previous position from which the feed material advanced, typically the position at which the feed material was last stamped, if the monitored position error of the press feed rolls or the monitored torque of the press feed roll drive motor deviates by more than a tolerance value from the expected position error of the press feed rolls or the expected torque of the press feed roll motor, respectively. Operation of the material stamping equipment may stopped after the feed material is moved back if desired.