| 摘要 |
An unwinding apparatus for a self-propelled wrapping machine (100) mobile around a load for wrapping the latter with a plastic material film (50), comprises frame means (2) for supporting a reel (60) of film (50); roller means (11, 12, 13, 14, 15) for unwinding and pre-stretching the film (50); at least one folding element (3) mobile along a narrowing trajectory (R) for abutting a first longitudinal edge (50a) of the film (50) and pushing the latter towards a second longitudinal edge (50b) of the film (50) so as to reduce a strip width (L) of film (50) exiting the apparatus (1); driving means (10) for moving the folding element (3) and comprising moving means (4; 104) supporting the folding element (3) and mobile along the narrowing trajectory (R); electric actuator means (5) connected to, and driving, the moving means (4; 104); a control unit (20) connected to the driving means (10) for adjusting a displacement and/or a moving direction of the moving means (4; 104); the wrapping apparatus (1) also comprises first sensor means (30; 130) coupled to the moving means (4; 104) for continuously detecting and measuring at least a displacement of the moving means and sending a related signal to the control unit (20) so as to control and adjust during wrapping the load a position of folding element (3) along the narrowing trajectory (R) and thus the strip width (L) of film (50). |
