GB1249902A - Apparatus for cutting and folding flexible sheet material - Google Patents

Abstract

1,249,902. Folding edges of sheet material. K. T. JENKINS. 16 Dec., 1969 [24 Dec., 1968 (2)], Nos. 61509/68 and 61510/68. Headings B4B and B5K. Flexible sheet material, e.g. textile fabric, in a continuous length resting on a work surface 1 in relaxed condition is cut and folded by gripping and holding transversely opposite portions of the longitudinal edges of the material at spaced positions adjacent to and on each side of a predetermined position where the material is to be cut transverse to its length, and, after cutting, a portion of material bordering a/or each 'cut edge is folded to form the trailing hem of a leading unit and/or the leading hem of the next following unit. A cutter assembly 23, Fig. 2, is mounted on rails 22 on a gantry 20, Figs. 1 and 2, and comprises a rotary knife 24 driven by an endless chain 26 driven by a reversible motor 27. The gripping means each comprise horizontal jaws 39, 40, Fig. 3a. A pivoted rocker 42 is mounted in a vertical slot 41 in the jaw 39 and one arm thereof has a plurality of pins 43 to extend into a slot 48 in the jaw 40 to grip the material and the other arm has an extension 44 to engage the upper surface of the jaw 40. The jaws 39 are urged closed by spring means 45 and are openable by a pneumatically-operated thruster 46 engaging rollers 47. A spring 49 retracts the pins 43 when the jaws are open. The jaw assemblies extend towards each other from eccentric seatings 70, Fig. 4, on gears 72 'fixed to coaxial stub shafts 73 mounted to rotate in crank arms 74 rotatable about coaxial spindles 75 rotatable in bearings 76 extending from subplatform members 30 mounted on platform units 29, Fig. 2, on the 'gantry 20. 'Gears 77 fixed on the spindles 75 mesh with the gears 72, the gears 72, 77 being of the same diameter. Gears 78 fixed to the spindles 75 mesh with pinions 79 rotatable by driving means 80. Gears 81 are -mounted on the 'arms 74 so as to rotate therewith and are rotatable by pinions 82 of driving means 83. To form a single fold, the means 80 rotate the spindles 75 'through 180 degrees to cause the jaws to gyrate and move along an arcuate path below the work surface and, to form a double fold, the means 83 rotate the arms 74 through 180 degrees to carry the shafts 73 along an arcuate path below the work surface, the gyratory motion of the gears 71 about the 'gears 77 causing 'the shafts 73 to rotate in unison to cause the jaws to gyrate. Fold controlling claments (50), (61), Figs. 5 and 6 (both not shown), each in the form of a slat of adjustable length are fed from magazines mounted transversely to the work surface 1 above and below the level thereof so that grooves (59) at the extremities thereof are engaged by pegs 60, Fig. 3a, on the jaws 39, 40 as the jaws move towards their closed position. The elements (50), (61), after completion of the folding operation and withdrawal of the jaws, remain in -attachment with the folded material unit until a permanent securing of the hem has been completed. The units 29 also carry opposed non-rotatable auxiliary grippers 12, Fig. 7, each comprising jaws -13, 14 on arms 15, 16 movable about a pivot 17 with a scissors-like action. The jaws 13, 14 are operable by a pneumatic thruster unit 19 acting against a spring 18. In use, the grippers 12 hold the material adjacent to the folding apparatus to prevent movement thereof during the cutting and folding operations. To prevent the fold controlling elements (50), (61) and the material held thereby from sagging during cutting and folding operations, displaceable support units 99, Fig. 8, are disposed below the positions where the rotatable gripping means effect folding and move with and support the elements (50), (61) during cutting, folding and securing. Each unit 99 comprises members 101 parallel to the path of the material, pivoted to the gantry 20 at one end and carrying at the other end spaced shafts 102 having freely rotatable rollers 103 mounted thereon. Narrow endless fabric belts 104 pass around the rollers 103. Prior to permanent securing of the hems, they are temporarily held in position by removable carrier units 110, Fig. 9, which are deposited on the folded hems prior to their release from the gripping means. Each unit 110 comprises parallel tubes 111 supported by adjustable stop blocks 112 and fixed blocks 113. Axially slidable members 114 are urged towards the blocks 113 by springs 115 and each member 114 has an extension 116 having downwardly projecting parallel pins 118 to engage a folded hem and the associated elements (50), (61). Each extension 116 has an arm 119 having a cam follower 120 engaged by a cam surface on the gantry 20 whereby the member 114 can be moved against the springs 115 to a predetermined position for engagement with the folded hem and the associated elements (50), (61). Extensions 121 releasably engage pick-up links on vertical chains 122, Fig. 1, which depose the unit 110 on a folded hem. An extension 123, Fig. 9, engages a pick-up link of horizontal chains 124, Fig. 1, by which the unit 110 and an attached secured hem are moved along the work surface for a subsequent operation. As shown in Fig. 1, the gantry 20 comprises two structures 7, 8, the downstream structure 7 providing support for means for folding and securing the trailing hem of a leading material unit and the upstream structure 8 providing support for means for folding and securing the leading hem of the next following material unit. An electrical circuit for the operation is described, Fig. 10 (not shown).