Patent GB-148395-A (GB)
Title: Improvements relating to machines for cross-cutting paper, cardboard and the like
IPC: B26D5/22
Filed: 1920-07-09
Abstract: 148,395. Spiess, G. April 28, 1919, [Convention date]. Feeding webs.-Relates to a machine for severing paper, cardboard, &c., of the kind in which the device for feeding the web to the cross-cutter comprises pairs of rollers, in which the rotation of each pair is periodically reversed so that, during one cycle of operations, two cuts are effected at or about the position of reversal. According to the invention, the feed-paper is supplied to the feed-rollers by a pair of rollers B<1>, B<2>, Figs. 1 and 2, rotated at a constant speed so as to deliver the paper without tension to the feed-rollers, the loop in the paper strip formed during the initial and end movements of the feed-rollers being taken up when these members are rotating at a greater velocity. Means are also provided to adjust the rotational speed of the feed-rollers relatively to that of the draw off rollers when the machine is adjusted to vary the size of the cut off sheets. The paper strip A is unwound by rollers B<1>, B<2> driven from the shaft 10, and is fed from the longitudinal cutters C<1>, C<2>, to a reciprocating cross cutter W by feed-rollers D<1>, E<1> interconnected through gearing. The rollers are driven from a shaft F by a toothed segment L<2>, which gears with a pinion N on the axle of the roller D', and is oscillated by a rotary crank-disk G through adjustable connexions L<2>, K, H. I. The upper presser rollers D<2>, E<2>, are rotated with the lower feed-rollers D', E', and they are mounted so as to be alternately raised at the end of the feeding and return movement respectively. This is effected by mounting the presser-roller axles on bolts U, V, the lower ends of which rest on a roller chain T. In operation, as the knife-arm W descends, a pawl Q on the reciprocating cutter arm P engages the teeth of a ratchet-wheel S, the rotation of which moves the chain a sufficient distance at each stroke for the bolts U, V to engage alternately with a link of the chain or a space between the bolts. By this arrangement, each pair of rollers alternately feeds the web forward, its movement when reversing being inoperative by the subsequent lifting of its pressure roller. At or about each position of reversal the knife is brought down to sever the web, cams Y<1>, Y<2> on the crank disk G acting on the lever Z. This lever is connected with a link 2, which acts on a lever 3 attached to one end to the lower end of the cutter arm P. Springs 5, 6 return the cutter to the raised position. The stroke of the toothed segments 2 driving the feed-rollers D<1>, D<2> is adjusted by altering the position of the pin H on the crank disk G driven from the shaft 10 by a belt 13 and gearing, as shown. This driving-mechanism is provided with an adjustment for regulating the speed of the feed rollers and of the cross-cutters. By this arrangement, the size of the cut-off sheet can be raised and the output of the machine regulated to correspond to the feed of the rollers B<1>, B<2>. The coned driving-belt engages with a pair of coned pulleys 11, 12, which are mounted to rotate with and be adjustable on the shafts 13, 14 respectively. Each member of the coned disks is attached by links to cross bars 17, 18 mounted on pivots mid-way between the shafts. By means of a hand-operated shaft 15 formed with opposite screw threads engaging nuts pivoted to the cross bars 17, 18, the parts of the pulleys can be moved to or from each other to vary the speed of the shafts, the speed of the shaft 10 being maintained constant. The Specification as open to inspection under Sect. 91 (3) (a) also included modifications (a) in which the rollers B<2>, E<2> may be raised and lowered by cam disks on the lower rollers, (b) in which a single pair of feed rollers are used. In the arrangement employing a single pair of rollers only, as shown in Fig. 8 (Cancelled), the segment 12 oscillates a shaft 8 through a pinion 9. The shaft drives the lower roller D<1> through pinions 10, 11 and a friction ratchet 13, 14 in one direction, and by a similar device through an intermediate pinion 12 on the other. In place of two friction ratchets, the roller may be driven through a toothed ratchet. This subject-matter does not appear in the Specification as accepted.