| 摘要 |
<p>A web of sheet material (3) is unrolled continously from roll (1) of sheet material by drive roller (16) against which the sheet is pressed by pressure roller (18), said sheet (3) being passed through guide channel (13, 15) and fed passed a perforating device (21, 22, 23) and a cutting device (24, 25) so that the sheet is provided with perforation lines and pieces of equal lengths are cut from the web. When material roll (1) is unrolled, following a signal by photo-electric cell (28), the roller (23) of the perforating device is raised and immediately after a piece is cut off by cutting device (24, 25) the direction of rotation of drive rollers (16, 17) is reversed (B min , C min ) so that the web (3) is withdrawn. As soon a the free end of said withdrawn web has passed the photo-electric cell (26), roller (23) is lowered again and the direction of rotation of drive rollers (16, 18) are brought back to directions (B, C) and pressure roller (18) is swung to a position in which it presses web (8) against drive roller (17) so that web (8) unrolled from the waiting roll (2) standing ready with its front end (8 min ) lying against retractable stop member (20) shoots forward and through between the perforating device (23, 21) to the cutting device (24, 25) where the front end (8 min ) arrives just after the cutter (24) has passed anvil (25).</p> |
