US Patent 7621107 Wrapping cart machine and method of wrapping

To palletize packages, a wrapping vehicle includes a vertically mounted drive screw having a plurality of ball nuts mounted at wrapping-effective distances from each other on the vertically mounted drive screw. Each ball-nut has a corresponding cantilever mounted to the ball nut to support a roll of wrapping material. A tension adjustment mechanism is mounted to adjust the resistance to motion of each roll of wrapping material and thus the tension on the wrapping material. The ball nuts are each connected to side support guide plates positioned to slide against the sides of mast housing the drive screw wherein said ball nuts are supported against tilting movement.