Device and method for changing automatically the size of packs in a conveyor, in particular for an automatic packaging machine

A conveyor device, in particular for an automatic packaging machine for paper rolls, comprising:

• a plane of advance,
• at least one pair of motorised flexible transmission members extending along a closed loop and bearing a plurality of transverse bars fastened to said at least one pair of motorised flexible transmission members,
• a plurality of thruster elements attached to said transverse bars, and
• a stationary adjustment station having at least one adjustment assembly configured to selectively receive the thruster element and adjust the position of the thruster element, wherein the adjustment assembly includes a shoe having at least two grip elements extending from the shoe, whereby as the shoe moves along a guide, at least one of the grip elements engages and moves the thruster element along the transverse bar between a first position and a second position.

A method for automatically adjusting the size of packs in a conveyor device, the conveyor device having at least one pair of flexible transmission members extending along a closed loop and bearing a plurality of transverse bars having a plurality of thruster elements, the method comprising:

• a) positioning a first transverse bar at an adjustment station, wherein said adjustment station includes at least one shoe and at least one actuator for moving said shoe and wherein said shoe is provided with at least two grip elements configured to selectively engage said thruster elements;
• b) selectively engaging the thruster elements supported by said first transverse bar by means of at least one grip element;
• c) selectively transversely positioning said engaged thruster elements by moving said grip elements and said shoe along a guide;
• d) moving said first transverse bar out of said adjustment station once the thruster elements supported by said first transverse bar have been transversely positioned along the transverse bar;
• e) positioning a second transverse bar at said adjustment station;
• and
• f) repeating steps (b) through (d) for said second transverse bar.