GB1158373A - Oscillating Shearing Apparatus - Google Patents

Abstract

1,158,373. Shearing fabrics. RIGGS & LOMBARD, Inc. 7 March, 1968, No. 11028/68. Heading D1S. Apparatus for shearing fibres 36 on the surface of a moving web 38 comprises a rest 40 to support the web, first and second cutting elements extending transversely of the web oppositely the rest 40 and oscillating drive means to move at least one of the elements into and out of shearing engagement with the other element to shear the fibres 36. In one embodiment, Figs. 1 and 3, a shearing head 10 comprises a cylindrical torque tube 12 mounted on a torsion bar 14 and carrying spaced steel cutting blades 16 preferably extending in a slight spiral configuration. The bar 14 is rotatably supported by bearings 18, 20 and is maintained spaced from the tube 12 by a bearing 22 and a fixed flange 24. An inertia element 26 with weights 28 at each end is fixed to the bar 14 and is oscillated by an eccentric 34 through a rod 32 so that when when the element 26 is moving counter-clockwise the tube 12 is moving clockwise and vice versa. A counterweight 30 may be added to the tube 12 diametrically opposite the blades 16. Ledger knives 42, 44, adjustable in position, extend into the gap between the rest 40 and the blades 16. In a modification (not shown), the oscillating drive system is similar to that described in U.S.A. Specification No. 2,939,223. In a further modification, Fig. 2 (not shown), the ledger knife 42 is omitted. In another embodiment, Fig. 4, a torsion bar 46 carries a pair of arms 48, 50 each carrying a shearing head 52 having spiral cutters 54 mounted thereon. The heads 52 are oscillated by an eccentric 34<SP>1</SP> through a rod 32<SP>1</SP>. The web 58 is guided by rollers 62, 64 so as to be sheared once on each side. In a further embodiment, Fig. 5, two arms 66, 68 are mounted above a rest 70 and each is fixed to a torsion bar 72, balanced by a counterweight 76 and oscillated by a drive 74 as shown in U.S.A. Specification No. 2,939,223. In yet another embodiment, Fig. 8, spiral cutting strips 80 are mounted on a core 82 of skeleton or openwork construction mounted on a torsion bar 84 for oscillation about its axis. A hood 86 encloses the core 82 and is connected by a duct 88 to a vacuum scorce to raise the fibres to be shorn. In a modification (not shown), a slit tube connected to a vacuum source is mounted in the core below the torsion, bar but above the cutting strips. Alternatively or additionally, compressed air may be directed through the web to raise the fibres, e.g. by a slit tube 90 mounted in the rest.