Tube spinning device

Abstract

Tube spinning device having a rotatable base plate (11) arranged perpendicularly adjacent to a mandrel (12) and thread applicators (13) connected to the base plate (11) with at least one thread applicator (13) being connected to an actuator (15). The actuator is arranged to move the tip (13a) of the thread applicator (13) back-and-forth in relation to the base plate (11). Furthermore, the actuator rod (16) is oriented at an angle to the mandrel axis (x), causing the tip (13a) to move towards and away from the mandrel axis (x) in the conical region (b) of the tube (21) under build-up.

Description

[0001] Tube spinning device

[0002] The present invention concerns a device able to manufacture tube shaped products from threads in a manner commonly referred to as "spinning". More concretely, the present invention concerns a device according to the preamble of claim 1.

[0003] Background

[0004] Tubes are produced in a high variety of manners. Tubes of synthetic polymer materials may be produced in several ways, and one particularly useful way is by spinning polymer threads onto a mandrel while continuously pulling the tube of the mandrel with the velocity at which the tube is produced, thereby producing continuous, joint-free tubes at any desired length.

[0005] Traditionally, tubes built up in this manner typically constitute three-dimensional webs from their inner to their outer diameter. An inherent disadvantage of such layered products is the risk of delamination between layers.

[0006] There are several examples of manufacturing tubes continuously as they are being deployed. Examples of this are shown in GB patent 1489186, US patent 2605202, US patent 2718684, US patent 4558971 and EP 3141787 Bl.

[0007] US 4558971 describes continuous manufacturing of plastic tubes. According to this method a band is wound around an internal stem by several spools with bands in a resin matrix circulate around the stem. The spools wind the band in opposite directions, whereby a pattern of crossing bands is achieved.

[0008] EP 3141787 Bl teaches a method for the manufacture of a tube from threads or bands that are spun onto a core element, the spinning taking place along a conical surface obtained by moving the core element back and forth during manufacture. This method avoids the risk of delamination between different layers of the tube, since the tube virtually is layer-free.

[0009] Objective

[0010] It is an object of the present invention to provide a device for cost-effective manufacture of synthetic continuous tubes in a manner eliminating the risk of delamination between layers.

[0011] The present invention

[0012] The above objective is fulfilled with the device according to claim 1 which constitutes the present invention.

[0013] Preferred, non-mandatory, embodiments of the invention are disclosed by the dependent claims. The objective of the present invention is fulfilled in that the present device produces tubes of a kind more generally described by the prior art publication EP 3141787 Bl. The device as such is not anticipated by or indicated by said publication, which teaches the use of a back-and-and-forth movement rather than the versatile use of thread applicators described herein.

[0014] While achieving said advantage in a new and inventive manner, the present invention furthermore allows, if so desired, to apply threads of a separate material, e.g. to influence physical or chemical properties of the product, using one or a few thread applicators for this purpose while using other thread applicators to supply threads of the main tube material. Such properties may be, but are not restricted to, flexural strength, tensile strength, acid resistivity, etc.

[0015] The device according to the present invention is generally useful for tubes of large diameter as well as small diameter, using actuators to direct the movement of the thread applicators allows programming of each actuator separately from the other actuators to obtain special effects when required, such as producing a certain length of the tube with a lower flexural strength than the other parts thereof, which may be beneficial at a point where the tube is expected to pass a bend.

[0016] Below, the invention is described in further detail in the form of non-limiting exemplary embodiments illustrated by accompanying drawings.

[0017] Figure 1 is a schematic simplified front view of an embodiment of the present invention.

[0018] Figure 2A is a schematic simplified side view of the embodiment of Figure 1.

[0019] Figure 2B is a schematic simplified side view of the embodiment of Figure 2A in a slightly different position.

[0020] Figure 2C is a schematic simplified side view of an embodiment similar to Figure 2B, also showing in part a tube under production.

[0021] Figure 3A is a schematic simplified side view of an embodiment of the present invention which is slightly different to the embodiment of Figures 1 and 2.

[0022] Figure 3B is a schematic simplified side view of a variant of the embodiment of Figure 3A.

[0023] The drawings are schematic and simplified which means that their actual design in practice may be significantly different from the simple design shown and that parts that typically will be present in a real-life embodiment may be omitted for the purpose of simplification and amplification of the features for which protection is sought.

[0024] Figure 1 is a front view of an annular, rotatable base plate 11 and a blank holder or mandrel 12 on which tube-shaped products may be manufactured with the present device. In the shown embodiment four thread applicators 13 are included, each one attached to the base plate 11 via a rod 16 and a bolt 17. Means to supply thread to the thread applicator is omitted from the drawing as is also means to rotate the base plate 11.

[0025] It is worth noticing that each one of the thread applicators 13 has a tip end 13a that is positioned outside of the perimeter surface of, and fairly close to, the blank holder 12. The tip end of the applicator(s) is the end from which the thread is passed onto the tube being manufactured. Preferably, the tip end 13a of the thread applicator 13 is less than 2 cm from the outer perimeter surface of the blank holder 12 it is at its turning point close to the base plate 11, i.e. when the actuator 15 is at a retracted turning point.

[0026] While other geometries may be used for specific purposes the outer perimeter surface of the blank holder 12 is typically a cylindrical surface.

[0027] While four thread applicators 13 are shown, the number of thread applicators may vary significantly and may be fewer or more e.g. a number of from 2 to 12, in other embodiments even more. For tubes of large diameter, the number of applicators could be much higher, even in a range between 50 and 100.

[0028] It should be noted that under operation, while thread is continuously supplied to the thread applicator, the blank holder, and thereby the tube under production, the base plate and all equipment attached thereto, is continuously rotated while the tube under production is slowly pulled off the blank holder with a speed adapted to the build-up of tube on the blank holder. The thread is typically made of a resin material or coated with a resin material that sets to a self- supporting tube in a time frame of no more than minutes.

[0029] Figure 2A is a side view of the device of Figure 1, showing a mounting plate 14 to which an actuator 15 is mounted as well as the bolt 17. While one end of the rod 16 is attached to the thread applicator 13 the other end is attached to the actuator 15. The actuator 15 is arranged to move the rod 16 back and forth like a piston between a retracted position and an extended position. As seen from Figure 2A, the mounting plate 14 is not parallel with the base plate 11, thus there is an angle between the length axis of the rod 16 and the centre axis X of the blank holder 12. Preferably, this angle is adjustable by an angle adjustment mechanism 18. While the angle adjustment mechanism 18 may be automatically or manually operated, it is typically only operated between manufacturing runs, not during such runs.

[0030] The angle of the rod 16 in relation to the blank holder axis X is within a range from 5 to 45 degrees and more preferred in the range from 10 to 30 degrees. The rod 16 typically is perpendicular to the mounting plate 14 while the bolt 17 is parallel with the rod 16. It should be noted that while the mounting plate 14 represents a convenient member for attachment of the actuator 15, any means suitable for holding the actuator 15 in a suitable position and angle is within the scope of the present invention.

[0031] It is emphasized that the orientation of the actuator and thereby the trajectory of the tip end movement of the thread applicator 13 may be obtained by other means than a mounting plate and that other means for positioning the actuator 15 with a desired orientation are within the scope of the present invention.

[0032] Now, referring to Figure 2B, in this view the actuator 15 has moved the rod 16 to an extended position at which the tip end 13a of the thread applicator 13 is further away from the base plate 11.

[0033] Figure 2C is a view similar to that of Figure 2B, though also showing part of a tube 21 under production with the present device. The thread applicator moves back and forth in the conical region "b" of the tube under build-up, said tube being pulled with a constant velocity adapted to the rotational velocity of the base plate and the thickness of the thread applied.

[0034] While the blank holder 12 is shown as penetrating the base plate 11 in the drawings, the blank holder and the base plate may also be arranged side by side, still co-axially arranged with one another, in which case there is no need for the base plate to be annular.

[0035] Figure 3A shows an embodiment of the present invention that is slightly different from the embodiments shown in Figures 1 and 2. In this version, production of the tube takes place upstream (to the left) of the base plate 11. The actuators have a somewhat different configuration but serve the same purpose of moving the thread applicators back and forth along the slope surface of the tube being built. In Fig. 3A, the actuator 15 is illustrated as attached directly to the base plate 11 with a fixed angle thereto.

[0036] In practice, the actuator will in most cases be supported by and / or attached to a mounting plate 14 as shown in Figure 3B, to provide a more rigid and reliable attachment to the base plate. The mounting plate 14 may have a non-adjustable position in relation to the base plate 11. An advantage of the configuration of Fig. 3A and in particular the configuration of Fig. 3B is that it is simple and robust, a disadvantage being that change of the angle between the actuator and the axis of the tube is more complicated or not even possible, depending on the attachment elements between the actuator and the base plate. The design and configuration of Fig. 3B allows the buildup of tubes with a diameter of at least 2 metres. Since the build-up of the tube is made in this manner, there are no discrete layers in the tube at which delamination can occur. This is consistent with the principle and the method laid out in EP 3141787 Bl.

[0037] However, while EP 3141787 Bl indicates the build-up to be conducted using a back and forth movement between a thread spool and a core element comparable with the blank holder. While EP 314787 Bl does not specific any device for its purpose, the present invention is all about a device suitable for production of this type of tube-shaped products, using specific measures never indicated before along with a somewhat amended method.

[0038] While at least some of, and typically most of, the thread applicators to be used in accordance with the present invention will be of the kind described above, the device also allows simultaneous use of at least one thread applicator of stationary type, arranged to build up an inner layer that could be of a different material, to influence the property of the completed tube, e.g. with regard to tensional force, flexural strength, temperature resistance or chemical resistance.

[0039] The present device allows versatile production of tube-shaped products, cylindrical as well as with other geometries, applying the general concept of a conical build-up while at the same time holding open the possibility of property-influencing layers in the tube wall. This is inherent in the ability to allow different thread applicators operate in different manners. If desired, different threads may cross one another during build-up, thus making a braided pattern more or less similar to a magpie nest.

[0040] Figure elements

[0041] 11 base plate

[0042] 12 blank holder

[0043] 13 thread applicator(s)

[0044] 13a tip end of thread applicator(s)

[0045] 14 mounting plate

[0046] 15 actuator

[0047] 16 rod

[0048] 17 bolt

[0049] 18 angle adjustment mechanism

[0050] 21 tube

Claims

Claims1. Tube spinning device comprising a rotatable base plate (11) arranged adjacent to a blank holder (12) with a blank holder axis (x) perpendicular to the base plate (11), a plurality of thread applicators (13) connected to the base plate (11), at least one of said thread applicators (13) being connected to an actuator (15) arranged to move the rod (16) in a back-and-forth movement, to cause the tip end (13a) of the thread applicator (13) to move back-and-forth in relation to the base plate (11) and the blank holder (12), while the actuator (15) is arranged with the rod (16) oriented at an angle different from the blank holder axis (x), to cause the tip end (13a) of the thread applicator (13) to move away from the blank holder axis (x) when moving away from the base plate(11) and vice versa.

2. Tube spinning device according to claim 1, wherein the at least one thread applicator (13) connected to an actuator (15) is pivotally connected to a rod (16) that is connected to said actuator (15).

3. Tube spinning device according to claim 2, wherein the angle of the rod (16) in relation to the blank holder axis (x) is within a range from 5 to 45 degrees, more preferred in the range from 10 to 30 degrees.

4. Tube spinning device according to claim 2 or 3, wherein the angle of the rod (16) in relation to the blank holder axis (x) is adjustable.

5. Tube spinning device according to any one of the preceding claims, wherein the tip end (13a) of the thread applicator (13) is less than 2 cm from the outer perimeter surface of the blank holder(12) when the actuator (15) is at its retracted turning point.

6. Tube spinning device according to any one of the preceding claims, wherein the thread applicator is pivotally attached to a bolt (17) as well as to the rod (16).

7. Tube spinning device according to any one of the preceding claims, wherein the actuator (15) is attached to a mounting plate (14) with the rod (16) perpendicular thereto, while the bolt (17) is also attached to said mounting plate (14) with an orientation parallel with the rod (16).

8. Tube spinning device according to claim 6, wherein the mounting plate (14) is attached to the base plate (11) via an angle adjustment mechanism (18).

9. Tube spinning device according to any one of the preceding claims, wherein the rod (16) is arranged through the base plate (11), the actuator (15) being attached to the rod (16) at the other side of the base plate (11) than the thread applicator (13).

10. Tube spinning device according to claim 1, wherein the at least one thread applicator (13) is connected directly to an actuator (15).

11. Tube spinning device according to claim 10, wherein the at least one thread applicator (13) is slidingly connected directly to the actuator (15).

12. Tube spinning device according to claim 10 or 11, wherein the actuator is attached to the base plate (11) via a mounting plate (14).

13. Tube spinning device as claimed in any one of the preceding claims, wherein at least one thread applicator is arranged stationary in relation to the blank holder.

14. Tube spinning device as claimed in any one of the preceding claims, wherein the blank holder (12) has a cylindrical outer surface.

15. Tube spinning device as claimed in any one of the preceding claims, wherein the base plate (11) is annular and that part of the blank holder (12) is arranged through the annulus thereof.

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