| 摘要 |
<p>1. Apparatus for longitudinally stretching plastics film, which is usable more particularly inpacking equipment, of the type comprising a stretching roller (16) on which the film is wound, more particularly about 180 degrees, the roller (16) comprising a plurality of generatives (22) disposed along a cylindrical envelope with the axis XX, means for driving the generatives (22) in rotation about the axis XX, and means for adjusting the angular speed of the generatives (22) relative to the axis XX during their rotation about the axis XX by means of the driving means, which enables the speeds of the generatives (22) in rotation at the entry points S and exit points E for the film to be in a ratio corresponding to the stretching ratio of the film, characterized in that the generatives (22) are secured rigidly to one of the ends of approximately radial arms (24, 26) and at a uniform distance R from the axis XX of a shaft (20), the shaft (20) comprising collars (32, 34) or the like on which the arms (24, 26) are mounted at their other end so as to pivot in a plane perpendicular to the shaft (20) by means of pivots (28, 30) ; and in that the means for driving the generatives (22) in rotation and for adjusting their angular speed comprise a drive shaft (38) with the axis YY rotating, by means of pinions (66, 68, 70, 72), the collars (62, 64) having the axis ZZ offset at a distance d from the rotational axis XX of the generatives (22), the collars (62, 64), at a distance r from the axis ZZ, supporting bushes (80, 82) in which the arms (24, 25) are mounted so as to slide, the shaft (20) being rotated at a speed equal to that of the collars (62, 64) by means of pinions (84, 86) or the like.</p> |
