GB980446A - Method of and apparatus for producing tubes of non-circular cross section - Google Patents

Abstract

980,446. Making non-circular tubes. J. M. MACCHIONE. Sept. 20, 1962 [Sept. 28, 1961], No. 35833/62. Heading F2P. [Also in Division B4] Apparatus with means for winding a number of tapes on to a former to form a non-circular tube in such a manner that some portions of the surface of the tube engage the former with a greater pressure than others, the surface of the tube intermediate such portions being non- planar, has means for causing said intermediate surfaces to move towards a planar configuration thus reducing pressure between the tube and the former to allow relative movement of the former and the tube for withdrawal of the former (Figs. 18 and 19). An arbor 35 is rotatably mounted in prolongation of a piston rod 31 of an air cylinder controlled by a solenoid air valve 81 for to-and-fro motion along a frame F together with the interconnected crossheads 32, 32<SP>1</SP>. An electric motor 80 is linked thereto by a worm-gear and toothed wheel (Fig. 6, not shown) which engages in a rack 103 to control the outward movement of the arbor. A " freewheel" clutch device allows a rapid return stroke. Tapes 61 of paper or the like are gummed at 60 and after winding on are laid by rollers 125R to 128R mounted at 63 in an annulus 110 (Fig. 12). The annulus 110 is driven through belts and gears 64 at a selected speed whereby the pitched winding of the tape may be regulated. The rollers 125R to 128R are adjustable in two co-ordinates in the plane of the annulus 110 on bolts 120<SP>1</SP> to 123<SP>1</SP> and 125<SP>11</SP> to 128<SP>11</SP>. The rollers also serve to rotate the arbor. Beyond the rollers the tube bulges as in Fig. 18 and the means for causing the sides of the tube to become planar comprises pairs of gripping jaws 131, 132 and 1311, 132<SP>1</SP>, seen edge on and in side-view in Figs. 14 and 16. Parallel rods 150 extend through bores 136 in the jaw assemblies 130 and 130<SP>1</SP> and through slots 144 in cam-plates 143 mounted on a square frame 140 which is carried on the rotated annulus 110 (Figs. 2 and 13). Springs 151 connect the ends of the rods 151 so that when the arbor and carriage retract they aid the converging cam slots to cause the jaw assemblies 130, 130<SP>1</SP> to converge and apply pressure to the bulged sides of the tube as in Fig. 19. A second tube gripping means (Figs. 10 and 11, not shown) is mounted free to rotate with the arbor in a crosshead 68 keyed to the connecting rods 32 of the other crossheads. In this a pair of serrated jaws are mounted on spring-loaded arms extending slightly forward from the transverse direction on vertical pivot rods 17 carried in brackets on a sleeve rotatable in the crosshead. The jaws engage opposite sides of the tube on the arbor to prevent rearward movement between the two but, by flattening the tube sides, allows easy withdrawal of the mandrel from the tube. A cut-off mechanism 70 (see Division B4) is pneumatically operated to sever the forward end of the tube at the same time as the carriage is ready to move from its fully retracted position. In the cycle of operations, after the solenoid valve 81 has operated to supply air to the cylinder 30 to drive the arbor 35 which is being turned by the motor 80 to wind on the tapes to form the tube the forward movement continues until a projection 85 on the crosshead 32 meets an adjustable member 86 on a longitudinally movable bar 87. Movement of this bar actuates a lever 88 to switch off the motor but the carriage carries on under its own momentum until it meets a cam surface 87<SP>11</SP> which depresses a lever 88<SP>1</SP> causing the solenoid valve 81 to admit air to the other side of the piston in the cylinder 30 to retract the arbor ready for a new cycle of operations.