Apparatus for Maintaining Tension in a Vertically Positioned Horizontally Traversing Plastic Film Web

摘要

In an automated machine that forms a vertically positioned and horizontally traversing web of plastic film into bags and fills the bags with material, the apparatus maintains tension in the plastic film web and supports and maintains the web horizontally aligned as it traverses through the machine. The apparatus includes upstream and downstream guide rollers. The upstream roller is mounted on an arm which is rotatably biased about a vertical axis and is thereby moveable. The upstream roller has an outer concave perimeter surface and the downstream roller has an outer convex perimeter surface. A longitudinal edge portion of the web extends horizontally from an upstream location, around the upstream roller, to and around the downstream roller and to a downstream location. The web extends vertically below the longitudinal edge portion. A rotational sensor coupled to the arm provides an output signal representative of the location of the arm.

主权项

1. A apparatus for maintaining tension in a vertically positioned web of plastic film traversing horizontally from an upstream location to a downstream location, said apparatus comprising:
an upstream guide roller rotatable about a vertical axis; a downstream guide roller rotatable about a vertical axis; wherein a longitudinal edge portion of said plastic film web extends horizontally from said upstream location, around said upstream guide roller, to and around said downstream guide roller and to said downstream location; wherein said plastic film web extends vertically below said longitudinal edge portion; and, wherein at least one of said upstream guide roller or downstream guide roller are moveable relative to said upstream and downstream locations, whereby tension is maintained in said web longitudinal edge portion and said web is supported and maintained horizontally aligned.