| 摘要 |
An apparatus for stretching a continuous plastics film in a packaging machine (11), in which products (12) fed one after the other are wrapped and sealed within said continuous film, comprising a first conveyor belt (13), a transverse welding apparatus (14) and a second conveyor belt (18), in which the transverse welding apparatus consists of a horizontally traversing carriage (15) which supports a pair of superposed welding bars (16,17) and a pressing belt (46) facing the second conveyor belt. The conveyor belts are driven by a speed variator (21) via a pair of transmissions, the first of which drives an end roller of the first conveyor belt and the second drives an end roller of the second conveyor belt by way of a linkage which varies the speed of the two conveyor belts, there being also provided upstream of said transverse welding apparatus, both above the first conveyor belt and operationally linked to the vertical movement of the upper welding bar (16), elements for clamping (51) the film onto the products (12) wrapped in it. <IMAGE> |
