Apparatus and method for removing a film of a package of objects
An apparatus ( 1 ) for removing a film ( 2 ) of a package ( 3 ) of objects having an elongated shape along a longitudinal axis comprises two pairs of rollers ( 7 and 12 ) suitable for pressing on the film ( 2 ) externally to hold the package ( 3 ) in place in a removal station ( 8 ); the two pairs of rollers are operatively connected to respective motor drives so as to apply a mechanical stretching to portions ( 13 and 14 ) of the film ( 2 ) in order to tear them, thus enabling the first pair ( 7 ) of rollers to remove the film ( 2 ) and free the objects from the package. Known film removal apparatus require a device for cutting the packaging film longitudinally, so that the speed of the apparatus is limited according to the length of the package and there is a risk of objects being damaged during cutting.
1. Apparatus for removing a film from a package of objects having a shape elongated along a longitudinal axis, having:
a first and a second roller defining a first pair of rollers each rotatable about a respective roller axis, for supporting the package in a configuration with the longitudinal axis extending parallel to the roller axes in a station for the removal of the film, the rollers connected to a first motor drive serving to rotate them around said roller axes;
a third and a fourth roller defining a second pair of rollers, movable between a raised position of non-interference with the package disposed in the removal station and a lowered position, in which the third and fourth rollers bear down upon the package, pressing it against said first and second roller;
means for tearing the film of the package disposed in the removal station so as to allow the removal thereof by the first pair of rollers,
wherein the means for tearing the film comprise a second motor drive, which is connected to the second pair of rollers and rotates them around their longitudinal axes, in such a way as to stretch portions of the film disposed between surfaces of the film that are in contact with said first and second pair of rollers, thereby causing the film to tear, and wherein the means for tearing the film further have:
means for reversing the direction of rotation of the third and fourth roller cooperating with said second motor drive;
and control means connected to said first and second motor drives and to said reversing means for enabling selective alternate stretching of: said portions of the film disposed between the surfaces of the film that are in contact with the first and second pairs of rollers, and a portion of the film disposed between surfaces of the film that are in contact with said third and fourth rollers.
2. Apparatus according to claim 1 , wherein the first motor drive is operatively connected to the first and second roller in order to rotate them in opposite directions, in such a way that surfaces of the first and second rollers contacting with the film of the package disposed in the removal station instantly move closer to each other.
3. Apparatus according to claim 1 , wherein the second motor drive is operatively connected to the third roller and to the fourth roller in order to rotate them in opposite directions, in such a way that surfaces of the third and fourth rollers contacting with the film of the package disposed in the removal station instantly move closer to each other.
4. Apparatus according to claim 1 , having means for cutting the film, operatively active on the portion of the film of the package disposed in the removal station which lies between the surfaces of the film in contact with the third and the fourth rollers, said cutting means interacting with the second motor drive so as to make cuts in the film when said portion between the surfaces of the film in contact with the third and fourth rollers is lifted away from the objects of the package by virtue of rotation of the second pair of rollers.
5. Apparatus according to claim 4 , having a carriage movable between a lowered position and a raised one, the second pair of rollers and the means for cutting being associated with said carriage.
6. Apparatus according to claim 1 , wherein said rollers have rough lateral surfaces in order to provide friction across the contact surfaces between the rollers and the film of the package disposed in the removal station.
7. Apparatus according to claim 6 , wherein said lateral surfaces are provided with a helical profile.
8. Apparatus according to claim 1 , wherein said rollers each have a lateral layer of predetermined hardness in order to provide friction across the contact surfaces between the rollers and the film of the package disposed in the removal station.
9. Apparatus according to claim 1 , wherein pick-up means are associated with a platform which moves along a predefined path in order to pick up a bundle made up of the objects of the package free of the film and transfer the bundle from the removal station to an exit station defined by the apparatus.