| 摘要 |
PCT No. PCT/SE87/00518 Sec. 371 Date Apr. 12, 1989 Sec. 102(e) Date Apr. 12, 1989 PCT Filed Nov. 5, 1987 PCT Pub. No. WO88/03474 PCT Pub. Date May 19, 1988.An arrangement in a bag-making machine for forming bag-defining lines of perforation and weld lines in an elongate web (7) comprises a driven roller nip including a nip roller (4) and a backup roller (5), by means of which the web (7) is fed through the machine (1), an elongate cutter (10) which is parallel to the rollers (4, 5) and rotatable about its longitudinal axis, and which when rotated is moved into engagement with the back-up roller (5) for making the lines of perforation, and two welding units (8) with sealing jaws (22) for making the weld lines. In order to allow optional adjustement of the spacing between consecutive lines of perforation and weld lines, the cutter (10) is separately connectible and disconnectible independently of the operation of the roller nip (4, 5) or of other drive means in the machine (1). The cutter (10) and the welding units (8) and driven by quick-acting step couplings for stepwise rotation of the cutter (10) through predetermined angles and for stepwise displacement of the sealing jaws (22). An angle sensor measuring the web length fed to the machine (1) controls the rotation of the cutter (10).
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