| 摘要 |
Film edges 9, 9 of a film web 1 are sensed by means of sensing heads 4, 4. The sensing heads 4, 4 are motively displaceable transversely relative to the longitudinal direction of the film web 1. The displacement results in signals which are proportional to the displacement and which activate servovalves 8, 8. These servovalves are connected to actuating cylinders 10, 10 which are themselves connected to chain-conveyor deflecting heads 6, 6. The signals from the servovalves activate the actuating cylinders which then adjust the chain-conveyor deflecting heads and thus move these up to the film edges. As a result of the adjustment of the chain-conveyor deflecting heads, the conveyors of the clip chains 14, 14 are also adjusted, thus resulting in a variation in the gripping depths, that is to say in the film strip retained by the clips. This brings about an oscillating movement of the film web after entry into the transverse stretching frame 16. |
