| 摘要 |
There is disclosed a food tray film wrapping machine having an improved film feeding mechanism particularly adapted to feeding pre-printed film from a continuous roll and assuring proper registration of the printing on the film-wrapped tray, including a receiving position for a large film roll provided with a pair of rollers for cradling the film roll, a film feed motor separate from the main wrapping machine motor, an automatic motor control responsive to optical sensors for sensing an index mark on the film sheet and for sensing the presence of a food tray at the machine wrapping station to stop and start the film feed motor, a perforating knife positioned adjacent the index mark sensor for perforating the film on a line across the film without separating it, and an arrangement of a filmfolding arm with gripping means for the film whereby the film sheet is separated at the perforation line as the folding arm tucks the trailing edge of the film sheet at the wrapping station under the food tray. The film feed mechanism also includes means for accommodating different spacing between printed patterns including a movable roller between the index mark sensor and the wrapping station which is operable to adjust the path length of the film between those two points allowing the pattern on the film to be registered in the desired position on the trays.
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