MASCHINE ZUM BEARBEITEN, VORZUGSZWEISE SCHWEISSEN UND TRENNEN EINER DOPPELTEN BAHN, INSBESONDERE BEIM HERSTELLEN VON SAECKEN

摘要

1315233 Making bags MASCHINENFABRIK WINDMOLLER & HOLSCHER 19 April 1971 [16 Feb 1970] 21935/71 Headings B5D and B5K In a bag making machine a web 5 is clamped between pairs of carrier members 15 which are guided along endless tracks 7 and 8 located on either side of a vertical web path 6. The members are moved along the web conveying portions 11, 111 of the tracks by a pair of belts 19 also clamped by the members. The members are lifted up the return track portions 12, 121 by projections 32 on chains 28, 281 engaging hooks 35 on the members. Forked catch members 36 mounted on chain drive shafts 25, 26 feed the carrier members into the start of the web conveying portions. The belts 19 are driven at a speed adjustably faster than the chains. Adjacent projections 32 and similarly hooks 35 on adjacent members 15 extend in opposite lateral directions so that a carrier member can overtake the next projection 32 on a chain in the web conveying portions 11 and 111. The web which may be a tube, or a longitudinally folded web, may be supplied directly from an extruder to pass underneath a floating roller 65 arranged to adjust the speed of the machine to keep the web tension substantially constant. Alternatively the web may pass to a feed roll 62, or 63 from a supply roll 71, or 72, photo-electric device 93-96 automatically causing the drive to be transferred from one feed roll to the other when a supply roll is exhausted. The carrier members are faced with resilient pressure strips containing an electric resistance wire to weld the web transversely when current is picked up from a contact rail in the web conveying portions 11, 111. A knife may be mounted in each carrier member of one group and arranged to move in a carriage across the web by a drive including knurled wheels rotated by rubber strips located in the web conveying and return portions. Alternatively a spring mounted roller may be mounted in each carriage with a perforating cutter member located in each carrier member of the other group.