| 摘要 |
Apparatus for folding a flexible tubing to form sack bottoms (60) (Figure 2) and for welding the bottom seams comprises a deck (1) Figure 1 having a central slot means (50, 51) for longitudinally transporting the tubing through the slot over a distance which is sufficient to permit the bottom to be formed, an arm or stirrup (70, 71) which is pivoted to the deck and drive, means (69, 78, 79) provided for pivotally moving said arm or stirrup through about 180 DEG between the mutually opposite sides of the deck, so that suckers provided on the mutually opposite opening-defining edges of the flexible tubing at locations which are centrally disposed between the side folds of the tubing section open the flexible tubing which protrudes beyond the slot to form a complete square bottom (60) and a strip-shaped tubing portion, which is formed in the tubing section as a continuation of the inner edges of the infolded triangular portions. Stretching pins (82, 90) See Figure 11 are provided, which serve to stretch the square bottom and to flatten the strip-shaped tubing portion and cooperate with those portions of the deck and of the pivoted stirrup in which the suckers are disposed. Welding bars 40, 41 Figure 2 are provided which seam the strip-shaped tubing portions together. <IMAGE> |
