GB991743A - Improvements in or relating to strip severing machines - Google Patents

Abstract

991,743. Severing by tearing. LAMSON PARAGON Ltd. Jan. 15, 1964 [Jan. 21, 1963], No. 1742/64. Heading B4B. A machine for severing a strip into sheets comprises at least one pair of co-operating strip feeding and restraining rolls 17 ... 20, Fig. 1, a plurality of pairs of co-operating pull rolls P disposed serially on the frame beyond the rolls 17 ... 20 and driven at a higher speed than the latter and arranged so that the bite of a selected one of certain pairs of pull rolls is adjustable to positively grip the leading, end portion of the strip and sever it at a point between the said pair of pull rolls and the slower-operating feeding and restraining rolls, while the rolls of the remaining pairs of pull rolls are slightly separated to afford support and guidance to the intervening portions of the strip without exerting any effective pull thereon. As described, the strip S is guided over a curved guide member 71 between the feed and restraining rolls 17 ... 20 which are spring-tensioned and adjustable by hand wheels 27 and include gripping surfaces. The strip S then passes the transverse breaker blade 67 which is adjustable longitudinally of the direction of movement of the strip and bristle-brush guides 82 deflecting the forward ends of the strips downwardly. The pull rolls P are secured in a sub-frame 40 mounted for sliding adjustment along ledges 41, the support for the sub-frame also including racks 45 and a pinion shaft 46 extending across the frame 40 and bearing pinions 47, 48, Fig. 4, which mesh with the racks and are controlled by a handwheel 49 for fine adjustment of the position of the pull rolls. Each pull roll pair a . . - g comprises lower and upper rolls 53 and 54 having knurled rollers 70, 71 mounted in bearings 65, 66, the upper rolls being vertically adjustable in slots 75, Fig. 3. The upper bearings 66 are urged downwardly by coil springs 77 seated between the bearing blocks 66 and a shoulder 78 on a vertical adjusting shaft 79, the upper end of which is adjustably threaded as at 80 into a similarly threaded opening in the bottom flanges of the upper framing. Adjacent each end of the roll shafts are thin plate-like lifting elements 85, Fig. 5, the lower portions of which have squared openings to receive the upper bearing blocks 66. The upper portions have openings 87 through which the eccentric lift rock shaft 90 extends. The upper margin of the opening 87 in the lifter element 85 is aligned with a notch 92, Fig. 6, and rests in the notch, when the upper roller 71 is in contact with the corresponding lower roller 70. The rock shaft 90 has fixed collars 95, 96, Fig. 4, positioned just inside the lifting plates 85, with a handle 98 fixed to the collar 95 so that the shaft may be moved from its operative position to one where the upper surface of the opening 87 in the lifting plate 85 rests upon the fully cylindrical portion of the shaft 90, and thus the bearing, roll shaft and upper roll is raised from gripping contact with the lower roll to the extent of the depth of the notch 92. The web passing through the roller bank P is maintained in proper alignment by lower guide strips 100 and upper strips 101 having bent lead-in and delivery ends 102, 103. The rolls are driven by the chain 60, a sprocket 110 and gearing 112, 113. The severed sheets are delivered on to a tape conveyer 120, 121. To facilitate severing the sheets from the web double coned crown roller may be mounted immediately beyond the second set of feed rollers F, the web being brought into contact with the crown roller by the appropriate set of pull rolls P, so that the tear is started by the ridge formed at the junction of the bases of the two conical sections of the roller. One or more such rollers may be provided. Specification 669,353 and U.S.A. Specification 2,778,424 are referred to.