Patent ID: 7347035

Claim:
An assembly for unrolling stretch film from a spool and pre-stretching the film as the film is fed from the assembly towards goods/products to be wrapped, the assembly comprising a first member for controlling forward movement of the film downstream of the spool in a direction in which the film leaves the assembly, a cutter for lacerating the film, arranged downstream of the control member,and a second member, arranged generally downstream of the cutter, for preventing return of the film in a direction opposite to that in which the film leaves the assembly; wherein the cutter comprises an arm hinged at an intermediate hinge position so as to enable angular displacement in a plane crossing the plane in which the film lies while leaving the assembly, a blade projecting transversely from one end of the arm, the arm being movable angularly between an operative position, in which the blade perforates the film, and a stowed position in which the blade does not interfere with the film, and an actuator for controlling angular displacement of the arm, and wherein the actuator has linear electromagnetic actuators acting on, respectively, an end of the arm opposite that which bears the blade and a point intermediate between the blade and the hinge position of the arm, such that the operative stowed positions are determined by appropriately opposite forward/backward configurations of the linear electromagnetic actuators.