| 摘要 |
<p>A packaging machine and method for simultaneously loading, sealing and severing bags. A first stepper motor, having an output, is coupled to a nip roll assembly. After a bag is loaded, a sealing mechanism is actuated to seal the loaded bag or bags. A sensor monitors movement in a pressure bar and terminates the sealing cycle if a jam is detected before the pressure bar engages a seal bar having a heater for sealing the bag. The stepper motor (32) is used to retract bags and sever a leadmost bag that is clamped between the seal bar by the pressure bar. A second stepper motor (30) withdraws the web from a supply (22) at a controlled rate to maintain tension in the web between the first and second stepper motors. A dancer roll assembly (42) includes an orientation sensor for controlling the second stepper motor to speed up, slow down or stop. <IMAGE></p> |
