| 摘要 |
<p>The apparatus for selecting and feeding web material (F1, F2, F3) from a plurality of supply bobbins (B1, B2, B3) of web material having different characteristics, comprises a selecting and dispensing device arranged on a slide (7) horizontally movable to and fro with respect to the means (T) which finally feed the film to the packaging station (P) of the packaging machine. On said slide there are mounted indexing means (13, 18) adapted to selectively bring into operative alignment with the feeding means (T) one draw-and-guide unit (A1, A2, A3) which draws the selected film and delivers it to the feeding means (T). The operative engagement between the draw-and-guide units (A1, A2, A3) is obtained by opening the feeding means (T) which consist of a superposed belts conveyor (101, 201) and pinch rollers (R1, R2) and inserting therebetween the forward portion (118, 218, 318) of the draw-and-guide unit. The opening of the feeding means is promoted by the movement of the draw-and-guide unit which carries a roller or opening pin (37) which acts on a suitable shaped plate (3) carrying the upper run (101) of the belt conveyor. Upon engagement of the draw-and-guide unit (A1, A2, A3) with the feeding means (T) there takes place also the operative engagement of a driving wheel (38) arranged on the feeding means (T) with a driven wheel (31) arranged on the draw-and-guide unit, which transmits the drive to the draw wheels (21, 121-22, 122) of the draw-and-guide unit.</p> |
