Method and apparatus for exchanging film rolls in a wrapping machine

In a machine for wrapping film around a product to be packaged including a rotatable wrapping crank, a film distribution sledge provided with tension rolls mounted on said wrapping crank, said film distribution sledge adapted to carry a roll of wrapping film which is wrapped around the product as said wrapping crank rotates, the improvement comprising apparatus for exchanging wrapping film rolls carried in said film distribution sledge, said film roll exchange apparatus comprising:

• a set of press rolls carried on a frame coupled to said film distribution sledge;
• means for moving said press roll-carrying frame between a closed position in which said press rolls are pressed against said tension rolls and an open position in which said press rolls are spaced from said tension rolls;
• and
• said press roll-carrying frame arranged to move to said open position prior to a film roll exchange operation so that a new film roll can be shifted into said film distribution sledge through the space between said press rolls and said tension rolls;
• further including
• means for grasping a leading end region of the film of said new film roll;
• transfer means for passing said leading end region of the film of said new film roll over said tension rolls to said grasping means;
• and
• said press roll-carrying frame arranged to move to said closed position after said new film roll is shifted into said film distribution sledge so that said press rolls and said tension rolls press the film between them for adjusting the tension of the film.

In a machine for wrapping film around a product to be packaged including a rotatable wrapping crank, a film distribution sledge provided with tension rolls mounted on said wrapping crank, said film distribution sledge adapted to carry a roll of wrapping film which is wrapped around the product as said wrapping crank rotates, the improvement comprising apparatus for exchanging film rolls carried in said film distribution sledge, said film roll exchange apparatus comprising:

• a set of press rolls carried on a frame coupled to said film distribution sledge;
• means for moving said press roll-carrying frame between a closed position in which said press rolls are pressed against said tension rolls and an open position in which said press rolls are spaced from said tension rolls;
• and
• means situated at a film roll exchange station for shifting a new film roll into said film distribution sledge through said space between said press rolls and said tension rolls when said press roll-carrying frame is in said open position.

A method for exchanging film rolls in a machine for wrapping film around a product to be packaged, said wrapping machine including a rotatable wrapping crank, a film distribution sledge provided with tension rolls mounted on said wrapping crank, said film distribution sledge adapted to carry a roll of wrapping film which is wrapped around the product as said wrapping crank rotates, comprising the steps of:

• moving a set of press rolls carried on a frame coupled to said film distribution sledge from a closed position in which said press rolls are pressed against said tension rolls to an open position in which said press rolls are spaced from said tension rolls;
• shifting a new film roll into said film distribution sledge through the space between the set of press rolls and the tension rolls;
• passing a leading end region of the film from the new film roll over the tension rolls to a grasping member in which said leading end region is locked;
• and
• moving said set of press rolls carried on said frame to said closed position so that the film remains between said tension rolls and said press rolls for adjusting the tension of the film.