Device for producing film rolls

1. A device for producing coreless film rolls, comprising:

a winding mandrel onto which a film sheet is adapted to be wound for producing a coreless film roll,

a transport arrangement comprising a rotatable member configured to be rotatable about an essentially vertical axis and configure to support the winding mandrel in a manner wherein an axis of the mandrel is essentially parallel to the essentially vertical axis about which the rotatable member is rotatable;

wherein the winding mandrel comprises a plurality of displaceable holding elements arranged in a longitudinal direction of the winding mandrel, the holding elements being operative for changing outer dimensions of the winding mandrel and having surfaces which are configured to directly engage the film sheet when it is wound onto the winding mandrel and to be retracted away and out of engagement with the coreless film roll when winding of the coreless film roll is to be separated from winding mandrel, and

a delivery station for separating the coreless wound-up film roll from the winding mandrel, the delivery station comprising a displacement device for displacing the coreless wound up film roll with respect to the mandrel when the mandrel assumes a delivery position so that the coreless wound up film roll is collected on a transport belt which has an essentially horizontal surface.

2. A device according to claim 1 , wherein the displacement device comprises a release device for allowing the holding elements to move inwardly to the release positions and away from the coreless film roll and receiving positions to which the holding elements are biased to engage with the coreless film roll during the winding of the coreless film roll.

3. A device according to claim 2 , wherein the holding elements are biased into the receiving positions and wherein a release device relieves the bias and induces the holding elements to move out of contact with the coreless film roll and into the release positions by reducing the bias in the delivery position.

4. A device according to claim 3 , wherein the bias is produce using one of hydraulic and pneumatic pressure and wherein the winding mandrel comprises a valve adapted to be opened for pressure reduction and the movement of the holding elements from the receiving positions to the release positions.

5. A device according to claim 1 , wherein the displacement device comprises a pull-off device for moving the film roll off the winding mandrel.

6. Device according to claim 5 , wherein the pull-off device comprises a ram adapted to be displaced in a longitudinal direction of the winding mandrel.

7. A device according to claim 1 , wherein the transport arrangement transports the winding mandrel from a wind-up station where the film sheet is wound onto the winding mandrel, to the delivery station.

8. A device according to claim 7 , wherein the transport arrangement comprises a plurality of winding mandrel holders each supported on the rotatable member for moving the winding mandrels from the wind-up station to the delivery station.

9. A device according to claim 8 , wherein the winding mandrel holders are configured such that the winding mandrel is adapted to be removably hung thereon.

10. A device according to claim 8 , wherein a transfer station transfers the winding mandrel from the wind-up station to the rotatable member.

11. A device according to claim 7 , wherein the transport arrangement is configured as an endless transport arrangement.

12. A device according to claim 1 , wherein an expanding station is located downstream of the delivery station and is operative for conditioning the winding mandrel so that the holding elements are biased into their receiving positions.

13. A device for producing coreless film rolls, comprising:

a plurality of winding mandrels onto each of which a selected amount of film sheet is adapted to be wound, said winding mandrels each comprising a plurality of operatively connected, displaceable holding element means for selectively varying outer dimensions of the winding mandrel and for providing surfaces which directly engage the film sheet when it is wound onto the winding mandrel, the holding element means being configured for retraction away and out of engagement with the coreless film roll for post winding separation of the coreless film rolls from the respective mandrel, and

transport means which comprises a rotating element that is rotatable about an essentially vertical axis and that carries the coreless film rolls respectively wound at a winding station, to a delivery station whereat each coreless film roll is separated vertically downward from the mandrel on which it is supported and whereafter each mandrel is subsequently expanded at an expansion station located downstream of the delivery station so as to assume a condition ready to have further film wound thereon at the winding station.

14. A device according to claim 13 , wherein the holding element means are constantly connected with the winding mandrels and form an operative part thereof.

15. A device according to claim 13 , wherein the delivery station is configured to displace the coreless film rolls vertically downward from the mandrels on which they are carried, onto a transport belt.