| 摘要 |
PCT No. PCT/IT87/00016 Sec. 371 Date Oct. 6, 1987 Sec. 102(e) Date Oct. 6, 1987 PCT Filed Feb. 18, 1987 PCT Pub. No. WO87/04998 PCT Pub. Date Aug. 27, 1987.A continuous paper band folding apparatus to form paper sheet piles is disclosed, which apparatus allows the formed folds to be squeezed and the paper band to be exactly cut in order to achieve separate piles of paper sheets. The apparatus comprises two rotating shafts carrying blades which engage the paper band and provide to form a fold therein by the particular radial and longitudinal arrangement of the blades forming a cusp symmetric with respect to the point of engagement with the paper band. Blades are rotated synchronously with the feed of paper band so that initially a natural loop is allowed to be formed in the paper band when the blades do not interfere therewith. Then the vertex of the cusp formed by the blades engages the paper band, thus causing it to be folded back. Afterwards, due to the radially offset arrangement of the blades along the shaft, the folding back of the paper band carries on progressively on either side of the central cusp, thus avoiding the undesired crumpling of the paper sheets. The apparatus is also provided with a retractable device which is synchronized with the rotation of the blade carrier shaft and guides the paper band to keep on the natural fold. |
