Patent GB-818149-A (GB)
Title: Improvements in or relating to continuous elements of reinforced plastic material and methods and machines for the production thereof
IPC: B29C53/80
Filed: 1956-05-07
Abstract: 818,149. Tube-making machines. BLANCHI, S., and LACOUR, R. May 7, 1956 [May 10, 1955; Feb. 23, 1956; March 15, 1956], No. 14027/56. Class 99(2). [Also in Groups X, XXVI and XXXIII] In a machine including means for feeding continuously thereinto juxtaposed wires coated with a plastic material in a fluid condition to produce a tubular element, there is means for distributing the wires in the form of a tube and comprising a number of reels 34 arranged on a circle, a mandrel 4 located inside a tubular sheath 2, and means for causing the mandrel and/or the sheath to vibrate at least in the radial direction, these two components being, one relatively to the other, free in the radial direction. As shown, a stationary crown 1 of reels 34 are distributed around the vertical axis of a framework 7 upon which is mounted a stationary, external sheath 2, a reservoir 5 containing a plastic material 39, a funnel 6, and a bowlshaped roller 3 and a mandrel 4 both suspended from a bar 8 carried by a disc 9 adjustable in a horizontal direction by screws 10 to permit centering of the roller and mandrel relatively to the sheath 2. Externally, the mandrel is partly cylindrical and partly frustro-conical in form. The bar 8 bears by a screw-and-nut height-adjusting assembly and an elastic suspension member 12 on a support 13 secured to a motor 14. Attached to the lower part of the support 13 is a tubular rod 15 which carries the mandrel 4. Alternatively, the mandrel is stationary and the sheath is suspended resiliently, or the sheath and mandrel are both suspended resiliently. Mounted on a radial series of spring blades 16 also carried by the rod 15, is a sleeve 17 over which the roller 3 is assembled, the centre of the part-spherical zone 3a of the roller being coincident with the point from which the blades 16 radiate so that by deformation of the latter that zone oscillates around the centre thereof; the roller rests on a shoulder 17a of the sleeve. The lower part of the convergent funnel 6 is formed by a truncated, rubber washer 18 and the funnel rests on a series of balls 19 so as to be movable freely in a radial direction. Interiorly of the rod 15 is a flat blade 22 connecting the vertical driving spindle of the motor 14 and a shaft 23 carried by the mandrel 4 and to which is keyed radial arms 25 mouting rollers 27; a ring 28 provided with axial grooves 28a bears against the inner wall of the mandrel. As the motor rotates the rollers 27, thrown outwards by centrifugal force, successively strike against each of the grooves to produce radial and tangential vibrations. Each reel 34, Fig. 3, on to which a single wire 35 or a layer of wires is or are wound with an intervening band of paper 36 is received on a drift 30, and a driven roller 32 withdraws the wires and the band, the wires being directed between the funnel 6 and roller 3 as shown in Figs. 1 and 2, and the band being wound on to a bobbin 31 connected to the roller 32 driven by belts 37. For hardening of the plastic material the sheath 2 is provided with tubular coils 40 through which is circulated a hot fluid and tubular coils 41 carrying a cold fluid, or other devices which operate by high frequency electric heating or gamma radiation ; also, the sheath has a resilient wall portion 42 which defines a chamber 43 containing a fluid subjected to lowfrequency pulsations for the purpose of facilitating the sliding of the plastic-coated wires between the sheath and the mandrel 4. Below the sheath 2 and suspended from the mandrel 4 is a sheath 2a, reservoir 5a and a crown 1a of reels 34a, the sheath 2a being optionally provided with a mandrel 4a. The crown of reels 34a which rotate about the vertical axis of the machine are mounted by means of supports 44 of adjustable inclination on a plate 45 resting on rollers the spindles of which are secured to a stationary member 46; the plate 45 is rotated by a motor 47 and a friction roller 48. The roller 32a of each reel 34a and which correspond to the rollers 32 of the reels 34, is driven by a friction roller 49 contacting an inclined track 50, axial movement of the roller 49 on the track allowing adjustment in the speed of withdrawal of the wires from the reels 34a relatively to the speed of rotation of the plate 45; a roller 52 in frictional contact with a track supported by the plate 45 is connected by a mechanical transmission 53 to the spindle of each roller 32, the roller 52 being axially adjustable to allow exact correspondence between the speeds of withdrawal of the wires from the reels 34 and 34a. Over the entire internal periphery of the sheath 2 and at the lower part thereof is at least one groove 54, Fig. 2, which permits the injection of a plastic material, different from or similar to that contained in the reservoir 5, on to the tube 60 previously formed by the wires 35 drawn from the reels 34 and to facilitate the adhesion thereto of the wires 35a drawn from the reels 34a. For drawing the tube 61 through the machine there is located a short distance from the internal wall of the sheath 2a, Fig. 5, and mounted on a support 56 connected to a non-rotary element such as the mandrel 4, a series of belts 55 driven through bevel gears connected by a blade 57 to the shaft 23 ; alternatively, belts 55a, Fig. 1, are located at the outer wall of the mandrel 4a, or two series of belts arranged face-to-face and located one on each side of the tube 61 are used. The belts may be replaced or augmented by means for actuating the mandrel 4 in an alternating axial movement and by a rubber covering formed with teeth which grip the tube 60 during the downstroke of the mandrel but which during the upstroke of the mandrel release the tube; also, there may be a series of nozzles 62, Fig. 1,, for projecting on to the tube jets of fluid to facilitate extraction of the tube from the machine, and the fluid is so selected as to deposit on the tube a coating, which may be permanent, with lubricating properties to assist introduction of the tube into a subsequent group of tube-fabricating devices. In operation, the support 13 is raised by slings 59, Fig. 1, to introduce the wires 35 between the funnel 6 and roller 3 and the motor 14 is started to produce radial and tangential vibrations for the purpose of distributing the plastic-coated wires uniformly over the periphery of the zone 3a and during passage thereof between that zone and the lower lip of the washer 18. Air and other gas bubbles carried by the coated wires are liberated in the space between the sheath 2, the bottom of the zone 3a, and the mandrel 4, and such liberation is completed by the lowfrequency oscillations of the wall 42. The process of hardening the plastic material is performed by the heating coils 40, the hardening being slowed down by the cooling coils 41. After coating of the primary tube 60 comprising longitudinally disposed wires, has been carried out at the groove 54 in the sheath 2, the wires 35a are wound helically thereon and the completed tube 61 emerges from the sheath 2a. In a modification, the sheath has a resilient and flexible wall held by a ring which is subjected to radial and axial vibrations by vibrators ; the bath of plastic material also is subjected to the action of a vibrator. In other modifications, (a) the reservoir 72, Fig. 8, is supported by the sheath 70 and an electromagnetic connection is provided between the sheath and the mandrel 71; the latter carries a ring 78 of ferromagnetic material and an electromagnet 76 is provided on the sheath whereby a variation in the electrical current enables longitudinal adjustment of the mandrel in the sheath and permits the mandrel to oscillate in the longitudinal direction, (b) a number of electromagnets associated with rheostats are arranged around the sheath where the sheath is disposed horizontally, or where the tube is brought from the vertical orientation of manufacture to a horizontal disposition, or if a tube of non-uniform thickness is to be made, (c) electromagnetic means are provided to cause the mandrel and/or the sheath to vibrate or to cause the mandrel to ratate, (d) the sheath 70, Fig. 10, carries a coil 76b and the mandrel 71 which is caused to vibrate radially has a spindle 80 on which is slidingly mounted a spring-urged mass 81 of ferro-magnetic material, and (e) the mandrel is provided with a magnetic bar, and a series of coils are distributed around the sheath. In further modification the mandrel 71, Fig. 12, is caused to rotate about its axis under the influence of a magnetic field created by coils 76c and a winding 86, the mandrel being hollow and serving as a reservoir for the plastic material 73 fed in by a pipe 90 and which is dispensed through openings 89 in the wall of the mandrel. The latter is carried on a tube 88 and mounted on a thrust ball-bearing 87. In a still further modification, the mandrel is constituted by a series of magnetic plates embedded in an elastic mass having a toothed profile. The machine may be modified and adapted to form a pipe-line in situ. The term "wires" includes continuous elements of cotton, jute, wool, hair, glass, or natural or artificial rubber.