Patent ID: 6164047
Filing Date: 2000-12-26
Classification: B65B

Abstract:
A device for cutting a plastic film (1) with width (L), used to wrap groups of palletized products in machines comprising:a platform (3) rotating about a first vertical axis (Z) in a direction of wrapping (A) and supporting on a surface thereof a group of products to be wrapped to form a pack (2), by said rotation of the platform (3), with the film (1), wherein a free edge of the film is attached to the platform (3);a reel (4) supported for rotation about a second vertical axis (Z1), said reel holding film that can be unwound therefrom and being supported by a frame (8) located adjacent the platform (3) and allowing the reel (4) to be moved vertically up and down, during said wrapping, between two end positions, one of said end positions being the lowest, in which the reel (4) is adjacent the platform (3), and the other of said end positions being the highest, in which the reel (4) is distanced from the platform (3) at a height (H1) approximately the same as the height (H) of the pack (2);means (5) for reducing the width (L) of a section of film (1) extending from the reel (4) to the pack (2), thereby defining a band (C) of the section adjacent the surface of the platform (3); and,a gripper and cutting unit (6) for the band shaped section (C), said gripper and cutting unit attached to the platform (3) and intercepting and cutting the band (C) when the platform (3) performs a wrapping rotation, wherein the means (5) for reducing the width of the band (C) of film (1) are attached to the frame (8), between the reel (4) and platform (3), and movable along a third vertical axis (Z2) parallel with the second vertical axis (Z1) of the reel (4) and partially synchronized with the reel, said width reduction means (5) comprising:a rod (9), pivoting at one end on the frame (8) and including an idle roller (9r) for contact with the film (1) and extending transversely relative to the section of film (1), said rod (9) being controlled by a guide pin (10), the latter being vertically mobile by means of a motor-powered chain (11) also acting upon the reel (4), said pin (10) angling the rod (9) between two end positions, one being a raised, non-operating position, in which the rod (9) is distanced from the film (1), and the other being a lowered, operating position, in which the rod (9) is horizontal and at a height lower than the height of the reel (4) in its lowered position, allowing the roller (9r) to reduce the width of the band (C).