A DOUBLE UNWINDING UNIT FOR ROLLS OF ROLLED MATERIAL WHICH IS EQUIPPED WITH A DEVICE FOR WELDING THE TRACKS TO BE UNWINDED

摘要

Unwinder unit for rolls (B1, B2) of sheet-like material (M), comprising a pair of unwinder shafts (1, 2) for respective rolls, arranged on opposite sides of a plane of symmetry (X) and suitable for feeding the material onto said plane and beyond it to an equipment downstream. The unit comprises a device (8) for splicing the tail end of a roll being unwound from one of said shafts to the leading end of a new, full roll installed on the other shaft, the device in turn having a configuration symmetrical to the plane of symmetry (S) and comprising a pair of splicing cylinders (11, 12), arranged on either side of the plane of symmetry (X), revolving around their respective axes and capable of moving closer together and further away from each other, the position in which they come closest coinciding with a condition of mutual contact; groups of suction holes (113) formed in lines along generatrices of the splicing cylinders (11, 12), for withholding the material against the cylinders and deviating it away from the plane of symmetry (X); first cutting means (13) for cooperating with the cylinders downstream of the area of mutual contact to cut the material withheld against the cylinder along a generatrix, second cutting means (24), arranged upstream; and means for controlling the cylinders, capable of synchronizing their rotation with the speed at which the material (M) is unwound.