Apparatus and method for changing unwinding units in a wrapping machine, and unwinding apparatus

Abstract

An apparatus associated with a wrapping machine includes at least one unwinding unit for the wrapping machine for wrapping a load with a film, and shuttles that are movable along a path and suitable for receiving and supporting an unwinding unit to be replaced and to be dismantled from the wrapping machine, or a new unwinding unit to be mounted on the wrapping machine. The shuttles operate along a substantially horizontal operating direction to dismantle and receive from the wrapping machine an unwinding unit to be replaced or to transfer and mount on the wrapping machine a new unwinding unit. The apparatus includes a supporting unit fixed to the wrapping machine and arranged to be coupled to, and supported by, the unwinding unit, the unwinding unit including a first coupling device, and the supporting unit including a second coupling device, the first coupling device and the second coupling device being mutually coupled or uncoupled along the operating direction.

1 - 32 . (canceled) 
     
     
         33 . Unwinding apparatus for an wrapping machine, comprising
 (a) a support unit connected with the wrapping machine;   (b) an unwinding unit removably connected with said support unit, said unwinding unit including a reel of film and a plurality of rollers for unwinding said filth froth said reel and winding it around a load, said rollers including first and second pre-stretching rollers for unwinding and pre-stretching said film; and   (c) a driving assembly connected with said support unit for rotating said pre- stretching rollers.   
     
     
         34 . Apparatus as defined in  claim 33 , wherein said driving assembly includes at least one motor and first and second transmissions, said first transmission being driven by said motor and said second transmission being driven by said first transmission for rotating said pre-stretching rollers. 
     
     
         35 . Apparatus as defined in  claim 34 , wherein said first transmission includes a pair of flexible elements driven by said at least one motor and said second transmission includes a pair wheels connected with respective pre-stretching rollers, each flexible element engaging and rotating a respective wheel. 
     
     
         36 . Apparatus as defined in  claim 34 , wherein said first transmission includes a pair of movable members rotated by said at least one motor and said second transmission a pair of followers Connected with respective pre-stretching rollers, each movable member engaging and rotating a respective follower. 
     
     
         37 . Apparatus as defined in  claim 34 , wherein said motors are mounted on said support unit and connected with said first transmission. 
     
     
         38 . Apparatus as defined in  claim 34 , and wherein said wrapping machine includes a frame, said motors being connected with said frame and said driving assembly includes a third transmission connecting said first transmission with said at least one motor. 
     
     
         39 . Apparatus as defined in  claim 33 , and further comprising movement means connected with the wrapping machine for moving said support unit and said unwinding unit coupled therewith with respect to the load. 
     
     
         40 . Apparatus as defined in  claim 33 , wherein said rollers include at least one guide roller for guiding said film from said reel to said pre-stretching rollers and from said pre-stretching rollers toward said load to define a wrapping angle of said film greater than 180°. 
     
     
         41 . Apparatus as defined in  claim 33 , wherein said pre-stretching rollers are adjustably connected with a frame of the wrapping machine to vary the axes between said pre-stretching rollers. 
     
     
         42 . Apparatus as defined in  claim 33 , wherein said unwinding unit includes a first coupling device and said support unit includes a second coupling device, said first and second coupling devices operating in a horizontal operating direction. 
     
     
         43 . Apparatus as defined in  claim 42 , wherein said first coupling means comprises a set of rails and said second coupling means comprises a seat for receiving said set of rails in a coupling position in which said unwinding unit is engaged with and supported by said support unit. 
     
     
         44 . A wrapping machine for wrapping a load with a film, comprising movement means for supporting and moving an unwinding apparatus as defined in  claim 33  relative to the load. 
     
     
         45 . A wrapping machine as defined in  claim 44 , and further comprising a replacement apparatus for dismantling and receiving from said support unit an unwinding unit to be replaced and for transferring and mounting on said support unit a replacement unwinding unit, said support unit being connected with said movement means.