Patent GB-821316-A (GB)
Title: Improvements in or relating to tube manufacturing machines
IPC: B31B155/00
Filed: 1955-10-14
Abstract: 821,316. Making paper bags. WINDMOLLER, A., and GENNERICH, M. [trading as WINDMOLLER & HOLSCHER]. Oct. 14, 1955 [Nov. 2, 1954], No. 29293/55. Class 94(2). [Also in Group XVI] A machine for manufacturing multi-wall stepped end bag tubes of the kind having a plurality of perforating devices for perforating continuous webs transversely at intervals, adhesive applying devices, means for advancing the webs through the machine, a web combining roller, and a tube forming device, is characterized by the perforation and adhesive applying devices being formed as units placed one behind the other, and by a photoelectric device for scanning printed matter on an outer web, the device being connected to an automatic regulating device which on operation of the photoelectric device corrects errors in the stepping distances of the lines of perforations in the unprinted webs. As shown, webs 7, 8 ... 12 are fed at the same speed in transversely stepped relation from supply rolls, not shown. The webs 7 to 12 are transversely perforated at intervals by perforating units 1, 2 ... 6 and then pass through adhesive applying devices 13, 14... 17 which apply adhesive strips to the webs on either side of the perforations. The perforating units and adhesive applying devices are driven at a constant speed, thus producing constant lengths of web to form the plies of the bag, the perforations in successive webs being longitudinally staggered in order to produce plies having relatively stepped ends. The webs pass over guide rollers 18, 19 ... 23 from which they pass in superimposed and transversely stepped relation to a web combining roller 24, a gluing device 25 which applies gluing strips along the longitudinal stepped edges, and then to a tube forming device 26 which folds and shapes the webs into a multiwall tube for production of a multi-wall bag, e.g., as described in Specification 763,730. The web paths between the various adhesive applying devices and the web combining roller vary in length. Should printing on the web 7 become out of register with respect to the perforations of that web, the lack of register is detected, preferably, by a photoelectric controlling device, not shown, as described in Specification 742,273 [Group XXXV] to either speed up or slow down the web. In order to preserve register of the web 7 with the other non-printed webs 8 to 12 and thus the correct stepping of ends of the bag lengths it is necessary to apply greater corrections to the webs 8 to 12 due to the greater lengths of these webs between the adhesive applying devices 14 to 17 and the web combining roller. The corrections are thus applied in proportion to these distances, e.g., by web engaging rollers 18 ... 23 carried by pairs of levers actuated by worm drives 30 ... 34 of varying drive ratios. The worms are mounted on a spindle 29 driven by a reversible electric motor 27 through a variable speed gear. The electric motor 27 may be controlled by the photoelectric control device. Alternatively, the spindle 29 may be driven by a pair of electro-magnetic clutches driven in opposite directions and controlled by the photoelectric device.