GB741906A - Improvements relating to machines for making tubing from sheet material - Google Patents

Abstract

741,906. Machines for making paper &c. tubes. KELLER, T. W. Aug. 28, 1953 [June 4, 1953], No. 23762/53. Class 99(2). In a machine wherein a sheet 12 of material, e.g., paper or polyethylene, is wrapped around a former shoe 14, comprising superimposed, verticallyspaced rectangular plates 44, to form a tube 16, mechanical anti-friction means is provided to reduce drag between the shoe and the material, that means including an endless belt 54 of spring wire one flight 56 of which extends parallel to the direction of movement of the material, and that flight over which the material is folded moving with the material. As shown, journalled peripherally-grooved pulleys 46 arranged at the corners of and between the plates 44 carry belts 54 the outer flights 56 of which are parallel to and project beyond the lateral edges 48 of the plates, the sheet material 12 being folded about the flights 56 without being pulled tightly against the edges 48. Additional pulleys may be mounted between the plates 44 to prevent sagging or inward pushing of the flights 56 by lateral contraction of the material 12. A bracket 18 supports the shoe 14 and arms 32 depending from the bracket hold up the side edges 28 of the material to initiate a folding operation, adjustable downwardly and forwardly inclined fingers 36 having crossed lower ends 38 urging the edges into overlapping condition on top of the shoe to form a longitudinal seam 30 which is glued or heat-sealed. A pair of wheels 42 inclined to the direction of movement of the material and adjustably supported on a bracket 40 maintain the edges 28 in overlapped relation until secured together. In a modification, pulleys 82, Fig. 8, and belts 84 are arranged on laterally adjustable bars 74, the inner flights 86 of the belts pressing the material inwardly between the plates 68 of the shoe to form gussets 62 in the tube 60. The pulleys at the entering end of the shoe are smaller in diameter than the remaining pulleys so that the material is progressively urged between the plates 68, or the leading pulleys have axes of rotation spaced further laterally outward of the side edges of the plates 68.