GB1070542A - Continuous folding of paper or other foldable material - Google Patents

Abstract

1,070,542 Corrugating webs. UNITED FIG. 4. STATES GYPSUM CO. Sept. 15, 1964 [Oct. 15, 1963], No. 37650/64. Heading D1S. Apparatus for forming longitudinal contours in a web 14 of foldable material comprises a convex surface 16 to receive the web 14 and change the longitudinal direction thereof; a supporting surface 18 to receive the web 14 from the surface 16 and comprising a plurality of longitudinally movable sections 46 converging in the direction away from the surface 16; a gripping surface 20 facing the surface 18 and comprising a plurality of longitudinally movable sections 126 in register with those of the surface 18, the sections 126 having slip resistant surfaces to contact the web 14 on the surface 18 to prevent relative movement between the web 14 and the sections 126; means for driving the sections 46, 126 in the direction of the convergence thereof so as to accumulate portions of the web 14 between the sections 126; means 164. 166 disposed between the sections 126 to longitudinally contour such accumulated web portions; and means for maintaining longitudinal tension in the contoured web 14 delivered from the exit end of the surfaces 18, 20 so as to preserve the longitudinal contours therein. The web 14 may be longitudinally creased prior to passing into the apparatus by one or more creasing rolls, e.g. steel cylinders with circumferential upraised portions, and opposed hard rubber back-up rolls. The web 14, Fig. 3, of paper or other foldable material passes from a source 12 over the convex surface 16 comprising a number of steel cylinders 34, Fig. 4, rotatably mounted on a curved shaft 36 rotatably mounted by shaft extensions 38a, 38b in the machine frame. The effective curvature of the surface 16 in accordance with the convergence of the surfaces 18, 20 is adjusted by rotating the surface about the extensions 38a, 38b and tightening locking bolts 44a, 44b (the latter not shown). The surface 18 comprises fifteen continuous "flat-top" chains 46 to which a series of synthetic resin platelets 48 are secured to form a continuous, but segmented, surface. At the web entry extremity the chains 46 rotate about sprockets 50 mounted on a shaft 52 curved to approximate to the curvature of the web 14 as at leaves the surface 16. The spacing of the sprockets 50, and thus the chains 46, is controlled by a "scissors" assembly, Fig. 6. This assembly comprises sections 70 a - b, 72 a - b, 74 a - b, 76 a - b,.. centrally pivoted on pins 78, 80, 82 (not shown), 84,.. which pass through a central circular aperture 64 and progressively larger slots 66a, 66b. 66c, in a plate 62. The pins are threaded into blocks 86, 88, 90, 92,.. which slide in a groove 68 along the length of the plate 62. Pivot pins 94, 96, 98, 100, 102,.. are provided at the extremities of the scissor sections and the upper faces of the sections are undercut below the pivot pins to form recesses into which extensions 106a of chain supporting strips 106 are fitted. The strips 106 are thus fanned or moved in and out in an arc-like fashion as the assembly is retracted or extended by handwheels 21a, 21b which rotate a shaft 118 engaging blocks 120, Fig. 6, 122, Fig. 7 (not shown), secured to the blocks 86, 88, 90, 92,.. the sprockets 50 are similarly moved in and out on the shaft 52 and are mounted on the blocks 86, 88, 90, 92,.. by roller bearings 114a, 114b, Fig. 8 (not shown). The strips 106 are "crowned" to conform to the web 14 leaving the surface 16, Fig. 12 (not shown), and progressively dissipate to a flat surface as the web 14 leaves the apparatus. The surface 20, Fig. 3, comprises six continuous "flat-top" chains 126 to which are secured platelets 128 having surfaces with a high coefficient of friction formed by cementing grit, sand paper or emery paper thereto. The chains 126 pass around sprockets 130 rotatably mounted in supports 132 each adjustably secured to a shaft 134 by set collars 136a, 136b, Fig. 2 (not shown), so that the convergence of the chains 126 can be altered. Bars 140, 142 guide the chains 126 and are secured at one end to the supports 132 and at the other end have notches therein loosely interfitted over notches in a plate 146, Fig. 22, which latter notches are aligned with sprockets 150 on a shaft 152. The web 14 is contoured by profile bars 164, Fig. 9, and a series of interfitting web guides comprising straddling rollers 166 rotatably mounted on holders 168 suspended from fixtures 22 on bars 24, see also Fig. 1. The bars 164 are continuously contoured and are initially rectangular in cross-section gradually increasing in height to a maximum height at the mid-point and from the mid-point to the downstream end the width narrows slightly and the edges are relieved to allow the pleat to fold under its own flat top, Figs. 14-20 (not shown). Rolling discs 170, rollers or bars may be provided to prevent the web material on top of the bars 164 from bowing upwardly. Hard rubber flattener rollers 172, Fig. 21 (not shown), may be provided at the web-exit extremity. The contoured web passes over a concave surface 30 to eliminate convergent tendencies therein. The surface 30 is a bowed roller similar to the roller 16 except that the web passes over the concave portion thereof. The web is then wound onto a take-up roll 32. The longitudinal tension in the web 14 is detected by the influence of its vertical component on load detection cells 188a. 188b, Fig. 21 (not shown), on which brackets 178a, 178b carrying the axes 176a, 176b of the roller 30 rest. The signal from the cells 188a, 188b is used to control the speed of the take-up roll 32 and /or the speed of the surfaces 18, 20. The drive for the surfaces 18, 20 is illustrated in Fig. 23 (not shown). In a modification (not shown), the downstream portion of the surface 18 has a concave profile complementary to that of the concave roller 30. In another modification (also not shown), the curvature of the shaft 52 and the surface 18 can be adjusted to match the curvature of the web 14 whenever the convexity of the roller 16 is changed.