Driven layon roller apparatus for film or sheet winders

Abstract

A driven layon roller apparatus for a plastic film or sheet winder is driven in rotation by a magnetic coupling. The magnetic coupling allows for torque to be transmitted to the layon roller of the apparatus to rotate the layon roller while adding little or no inertia and imposing little or no radial force to the layon roller as the layon roller moves position relative to the winder.

1 . A driven layon roller apparatus for winders, the apparatus comprising:
 a frame;   a central shaft supported on the frame;   a layon roller mounted for rotation on the central shaft;   a magnetic first coupling piece adjacent the layon roller, the first coupling piece being rotatable relative to the frame; and,   a magnetic second coupling piece mounted stationary on the layon roller, the second coupling piece being adjacent the first coupling piece wherein magnetic flux between the first coupling piece and the second coupling piece causes the second coupling piece and the layon roller to rotate in response to rotation of the first coupling piece.   
     
     
         2 . The apparatus of  claim 1 , further comprising:
 the layon roller having an axis of rotation; and,   the first coupling piece being rotatable around the layon roller axis of rotation.   
     
     
         3 . The apparatus of  claim 1 , further comprising:
 an empty space between the first coupling piece and the second coupling piece, the empty space preventing the first coupling piece and the second coupling piece from contacting.   
     
     
         4 . The apparatus of  claim 1 , further comprising:
 the first coupling piece having a flat surface;   the second coupling piece having a flat surface; and,   the first coupling piece flat surface and the second coupling piece flat surface being parallel and opposing each other.   
     
     
         5 . The apparatus of  claim 4 , further comprising:
 an empty space between the first coupling piece flat surface and the second coupling piece flat surface.   
     
     
         6 . The apparatus of  claim 1 , further comprising:
 the first coupling piece being a permanent magnet.   
     
     
         7 . The apparatus of  claim 1 , further comprising:
 the second coupling piece being a permanent magnet.   
     
     
         8 . The apparatus of  claim 1 , further comprising:
 a roll of film adjacent the layon roller.   
     
     
         9 . The apparatus of  claim 8 , further comprising:
 the layon roller being movable toward and away from the roll of film.   
     
     
         10 . The apparatus of  claim 1 , further comprising:
 the layon roller having a cylindrical exterior surface and a cylindrical interior surface, the cylindrical interior surface of the layon roller surrounding a hollow interior volume of the layon roller, and;   the second coupling piece being inside the layon roller hollow interior volume.   
     
     
         11 . The apparatus of  claim 10 , further comprising:
 the first coupling piece being inside the layon roller hollow interior volume.   
     
     
         12 . The apparatus of  claim 1 , further comprising:
 a drive transmission operatively connected to the first coupling piece, the drive transmission being selectively operable to rotate the first coupling piece.   
     
     
         13 . A driven layon roller apparatus for winders, the apparatus comprising:
 a frame;   a central shaft mounted on the frame and supported by the frame;   a layon roller mounted for rotation on the central shaft, the layon roller having an axis of rotation that defines mutually perpendicular axial and radial directions relative to the layon roller;   a magnetic first coupling piece mounted on the frame for rotation of the first coupling piece relative to the frame and around the layon roller axis of rotation;   a drive transmission operatively connected to the first coupling piece for rotating the first coupling piece; and,   a magnetic second coupling piece connected to the layon roller for rotation of the second coupling piece with the layon roller around the layon roller axis of rotation, the second coupling piece being adjacent the first coupling piece wherein magnetic flux between the first coupling piece and the second coupling piece causes the second coupling piece and the layon roller to rotate in response to rotation of the first coupling piece.   
     
     
         14 . The apparatus of  claim 13 , further comprising:
 the first coupling piece and the second coupling piece being separated axially by an empty space between the first coupling piece and the second coupling piece.   
     
     
         15 . The apparatus of  claim 12 , further comprising:
 the first coupling piece having a flat annular surface that extends around the layon roller axis of rotation;   the second coupling piece having a flat annular surface that extends around the layon roller axis of rotation; and,   the first coupling piece flat annular surface and the second coupling piece flat annular surface being parallel and axially spaced from each other.   
     
     
         16 . The apparatus of  claim 15 , further comprising:
 the first coupling piece flat annular surface and the second coupling piece flat annular surface being axially separated by an empty space.   
     
     
         17 . The apparatus of  claim 13 , further comprising:
 the first coupling piece and the second coupling piece being permanent magnets.   
     
     
         18 . The apparatus of  claim 13 , further comprising:
 a roll of film adjacent the layon roller.   
     
     
         19 . The apparatus  claim 18 , further comprising:
 the layon roller being movable toward and away from the roll of film.   
     
     
         20 . The apparatus of  claim 13 , further comprising:
 the layon roller having a cylindrical exterior surface and a cylindrical interior surface, the cylindrical interior surface surrounding a hollow interior volume of the layon roller; and,   the second coupling piece being inside the layon roller hollow interior volume.   
     
     
         21 . The apparatus of  claim 20 , further comprising:
 the first coupling piece being inside the layon roller hollow interior volume.