Unreeling assembly, particularly for labeling devices

Abstract

The present invention relates to an unreeling assembly, particularly for labeling devices, comprising a supporting frame for at least two reels of continuous film which are supported by a respective reel support, which can be actuated to rotate about an unreeling axis of the reel by a respective servomotor, and a motorized traction drum, which is designed to unreel the continuous film from one of the at least two reels of continuous film, between the reel of film being unreeled and the traction drum there being at least one element for tensioning the continuous film, the tensioning element being movable, with respect to the supporting frame, along a respective movement path, characterized in that it comprises control elements which operate on the servomotor and are adapted to control the position of the tensioning element along the respective movement path.

1 - 9 . (canceled) 
     
     
         10 . An unreeling assembly, particularly for labeling devices, comprising a supporting frame for at least two reels of continuous film which are supported by a respective reel support, which can be actuated to rotate about an unreeling axis of the reel by a respective servomotor, and a motorized traction drum, which is designed to unreel said continuous film from one of said at least two reels of continuous film, between the reel of film being unreeled and said traction drum there being at least one element for tensioning said continuous film, said tensioning element being movable, with respect to said supporting frame, along a respective movement path, further comprising control means which operate on said servomotor and are adapted to control the position of said tensioning element along the respective movement path. 
     
     
         11 . The unreeling assembly according to  claim 10 , wherein said control means are adapted to move on command said tensioning element between at least one first working position, in which said tensioning element is adapted to apply a preset tension to said continuous film being unreeled, and at least one second accumulation position for increasing the length of the continuous film that lies between said reel being unreeled and said traction drum with respect to the length of said continuous film, between said reel being unreeled and said traction drum, with said tensioning element in said first working condition. 
     
     
         12 . The unreeling assembly according to  claim 10 , wherein said control means are adapted to actuate said servomotors to move in a preset and gradual manner said tensioning element along the respective movement path according to a rule of motion which can be preset. 
     
     
         13 . The unreeling assembly according to  claim 11 , wherein said control means are adapted to move said tensioning element from said first working position to said second accumulation position by means of a variation of the angular velocity of said servomotor associated with the reel support that supports said reel being unreeled. 
     
     
         14 . The unreeling assembly according to  claim 11 , wherein said first working position of said tensioning element substantially corresponds to a minimum tension position, so as to allow the processing of continuous films with low grammage and/or with limited height. 
     
     
         15 . The unreeling assembly according to  claim 10 , further comprising, downstream of said traction drum, an applicator of labels obtained from said continuous film onto containers to be labeled. 
     
     
         16 . The unreeling assembly according to  claim 10 , further comprising a plurality of guiding cylinders between the reel of film being unreeled and said traction drum. 
     
     
         17 . The unreeling assembly according to  claim 10 , further comprising, between said at least two reels and said tensioning element, a joining station designed to provide a connection between an end portion of the continuous film being unreeled from the reel about to be depleted and an end portion of the film supported by the other reel. 
     
     
         18 . The unreeling assembly according to  claim 10 , wherein said tensioning element comprises a tensioning dandy roll, which is supported by said supporting frame so that it can rotate about a respective pivoting axis.