Patent GB-502606-A (GB)
Title: Improved method of manufacture of hollow tubular articles
IPC: B31C11/02
Filed: 1937-06-18
Abstract: 502,606. Making paper tubes; cutting cylinders etc.; lathes. HOSKING, H. G. W. June 18, 1937, No. 17071. [Class 99 (ii)] [Also in Groups VIII and XXII] A hollow tubular article of non-uniform cross-section, such as a chair leg, lamp-stand, flower pot, or a light fitting, is made by applying adhesive to one side of a web of compressed paper or cardboard of uniform width, winding the paper on a mandrel to produce a tubular blank, drying the blank, and shaping it externally by turning. In the machine shown in Figs. 1 and 2, paper drawn from a roll 15 is supplied with adhesive as it passes over a fluted roller 10, by a fluted roller 11 which dips into a bath 62 in which adhesive is maintained at a constant level by a pump 59 and overflow pipe 63. The pasted paper passes over a roller 155 and is wrapped around a collapsable mandrel 17 which is rotated through gearing 32, 33 from a shaft 20, which is connected by a clutch 22, 23 to a pulley 8 driven by an electric motor 2. After a number of layers of paper have been wound around the mandrel, the feed of the paper is stopped automatically by disengagement of the clutch. This is effected by a half-nut 36 carried on a screw-threaded portion 26 of the shaft 20 and mounted in a slide 30. As the shaft 20 rotates, the half-nut moves the slide downwards until it engages a stop on a rod 27, which by means of a fork 28 opens the clutch. The mandrel is made in two parts, the upper 42 being connected to the lower by an inclined groove so that when the upper section 42 is moved outwards by an arm 45 the mandrel collapses and, after a fork 49 which supports the end of the mandrel has been swung outwards, the blank is removed and dried. To re-start rotation of the shaft 20, the half-nut is held out of engagement with the screw-threaded portion 26 of the shaft by a cam while the slide is moved vertically by a counterweight 39, and then a locking-device. 35 is released to enable a spring 21 to effect engagement of the clutch. At starting, the paper may be fed positively to the mandrel by passing it between rotating rollers 16, 155, the roller 16 being mounted in a manually-operable fork 67. The blank is cut into two smaller blanks by placing it on a rotating shaft provided with an annular groove opposite a disc knife which is moved against the blank. The end of each blank is then grooved while the blank 188, Fig. 5, is held in the jaws 97 of a chuck mounted in a slide 98 which can be moved along a worktable by a rack-and-pinion gear 102, 101. The end of the blank is supported by a disc 104 projecting from a rotatable shaft 91 which carries knives 95, 96 to trim the end of the blank and produce an internal groove to facilitate connection of the blank to some other article. Shavings are drawn away through a suction hood 110. One end of the blank is then placed upon a chuck 116, Fig. 7, on a rapidly rotating shaft 112 and the other end is supported by a rotatable chuck 117 while a slide 121 is moved along the length of the blank by a rack-and-pinion gear 124, 125 to enable knives 129 guided by a fixed cam 133 to shape the external surface of the blank, A head 140, left at the end of the blank adjacent the chuck 117, is severed by a cutter 135 carried by a hand-lever 136, before the blank ' is removed from the chucks. Shavings are drawn away through a suction hood 141. The shaped blanks may be sand-papered, waterproofed, fireproofed, or metallized. A sheet of aluminium or steel may be incorporated between the layers in the blank. Specifications 20148 /89, [Class 96], and 20920/11, [Class 99 (ii)], are referred to. The Provisional Specification also states that the grooving and shaping operations may take place during the winding on the mandrel.