GB771615A - Improvements in or relating to the production of helically wound continuous tubing from strip material - Google Patents

Abstract

771,615. Paper &c. tubes. GEE MANUFACTURING CO., Ltd. Dec. 12, 1955 [Sept. 15 1954], No. 26707/54. Class 99(2) In a machine for making paper &c. tubes by winding strip material 11 helically on a mandrel 10 by means of an endless belt 12 looped around the mandrel and driven from rollers 13, 14 and cutting the tubing thus formed, the diameter of the tubing is adapted to be varied during production thereof while maintaining constant the length of tube severed, so as to compensate for variations in the characteristics of the strip material and in the performance of the machine. The outer cover of the tube may bear a unitary pattern in which case the variation may enable the point of severance to be located accurately relative to the pattern. As described, the mandrel 10 has a slight taper (1 in 1000) and is adjusted axially; alternatively, the mandrel may be inflatable and may be in the form of a distensible helix or it may be composed of segments with internal wedging means, whereby the diameter may be varied. The mandrel 10 in the Figure is fitted with a sleeve 10a slidable in a,bearing comprising a body 21 and a cap 21a and supporting a screw rotation of which traverses a nut 23 having an extension engaging a slot in the sleeve 10a. In a modification, the mandrel 10 slides in a head mounted in an arcuate guideway, and a bevelled pinion on the mandrel engages an arcuate rack whereby axial movement of the mandrel is accompanied by angular displacement thereof to compensate for lateral displacement of points on adjacent convolutions of the strip; cutting is effected by a rotary cutter operation of which is controlled by a target, by a measuring roller riding on the tubing and actuating a switch, or by synchronizing the tube winding mechanism drive with the cutter mechanism. According to the Provisional Specification, the mandrel has a taper of 1 in 4000.