GB2047379A

GB2047379A - Improvements relating to flexible tubes having mounting flanges

Info

Publication number: GB2047379A
Application number: GB7942554A
Authority: GB
Original assignee: VERSEIDAG
Current assignee: VERSEIDAG
Priority date: 1979-04-18
Filing date: 1979-12-10
Publication date: 1980-11-26
Also published as: DE2915525A1; GB2047379B

Abstract

A flexible tube (1) of textile material for conveying air or gas, is provided with a longitudinal mounting flange (2) formed of a single layer of woven material formed by the weave of the weft thread (7) of the material which forms the wall of the tube, the flange (2) serving to receive mounting elements and being integral with both of the portions of the wall of the tube from which it extends, and wherein the average number of warp threads (3) per unit length in the mounting flange (2) is greater than the average number of warp threads (3) per unit length in the wall of the tube (1), and /or the yarn used for the warp threads (3) of the mounting flange (2) has a greater tensile strength than the yarn used for the warp threads (3) of the wall of the tube (1), and/or the region of the intersection (5) of the mounting flange (2) and the wall of the tube (1) is woven with a firmer weave than the remainder of the tube, the said mounting flange (2) thereby having an improved resistance to mechanical stresses. <IMAGE>

Description

SPECIFICATION Improvements relating to flexible tubes having mounting flanges The present invention relates to flexible tubes of textile material, provided with mounting flanges.

Our British Patent Application No.

5489/78 Serial No. 1577274 discloses a flexible tube of woven textile material for carrying air or gas, provided with a longitudinal mounting flange formed of a single layer of woven material which is formed by the weave of the weft thread of the material which forms the wall of the tube, the flange serving to receive mounting elements, and being integral with both of the portions of the wall of the tube from which it extends.

Such tubes of textile material, which may be coated or uncoated, are useful for conveying air or gas.

We have now found that for certain uses the mounting flange of the flexible tube should be capable of withstanding higher stresses than those which the construction of our earlier patent can withstand. We have also found that the zone of the flexible tube where the mounting flange meets the main body of the tube can be pulled apart by the spreading action of the tube wall under high internal pressure. This results in leakages. Furthermore, an increase in the electrical conductivity of the material of the tube is very desirable in order to prevent a build-up of electrostatic charge, particularly when the tube is to be used underground; this prevents sparking.

It is therefore an aim of the present invention to provide a flexible tube of textile material having a mounting flange which is capable of withstanding higher mechanical stresses imparted to the flange by mounting elements.

Accordingly, the present invention provides a flexible tube of textile material for conveying air or gas, provided with a longitudinal mounting flange formed of a single layer of woven material which is formed by the weave of the weft thread of the material which forms the wall of the tube, the flange serving to receive mounting elements and being integral with both of the portions of the wall of the tube from which it extends, and wherein the average number of warp threads per unit length in the mounting flange is greater than the average number of warp threads per unit length in the wall of the tube, and/or the yarn used for the warp threads of the mounting flange has a greater diameter than the yarn used for the warp threads of the wall of the tube, and/or the yarn used for the warp threads of the mounting flange has a greater tensile strength than the yarn used for the warp threads of the wall of the tube, and/or the region of the intersection of the mounting flange and the wall of the tube is woven with a firmer weave than the remainder of the tube, the said mounting flange thereby having an improved resistance to mechanical stresses.

Thus for example by increasing the number of warp threads in the flange and/or by using warp threads having a larger diameter to form the mounting flange, and/or by using a yarn having higher tensile strength, the strength of the mounting flange i.e. its capacity to withstand mechanical stresses, more particularly those imposed by the mounting elements held by the flange, can be considerably increased.

Examples of such yarns having a higher tensile strength are more particularly types of yarns made of aromatic polyamides, also known as aramides.

Improved electrical conductivity can be achieved by the use of yarns consisting totally or partly of metal, carbon or boron. Said yarns may be, for example, multiple ply yarns having different types of fibres, e.g., aramides and carbon fibres, or mixed yarns. In the case of the said mixed yarns the conductive fibres are mixed among the other textile fibres as staple.

An increase in resistance to pulling apart of the intersection of tube wall and the mounting flange can also be achieved by a firmer weave, more particularly a leno wave or binding warp as shown in Fig. 3 or by an increase in the number of threads in the region of the intersection as shown in Fig. 4. Regions containing such an increased number of threads can extend, for example, at least 5 cm, e.g. 2 cm, into both the tube wall and the mounting flange. The increase in the number of threads can be made independently of the basic number of threads in the tube wall and in the mounting flange.

Depending on the forces to which the tube is likely to be subjected, the average number of warp threads per unit length in the mounting flange can be 20 to 30%, 30 to 50%, or at least 50%, greater than the average number of warp threads in the wall of the tube.

Similarly, the diameter of the warp threads used in the mounting flange can be 20 to 30%, 30 to 50%, or at least 50%, greater than the diameter of the warp threads used in the wall of tube.

The proposals according to the invention can also be extended to the entire tube wall in order to obtain the desired improved properties. However, since the tube wall itself, particularly in the coated state, does not generally necessitate such an improvement in its physical properties, such measures would generally involve an undesirable increase in the production costs and the weight of the tube.

Specific embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 shows a diagrammatic, partial, transverse cross-section through one embodiment of a flexible tube in accordance with the present invention, Figures 2 to 4 show cross-sections, similar to that of Fig. 1, of further embodiments of a flexible tube in accordance with the present invention, and Figure 5 shows a diagrammatic cross-section of a flexible tube in accordance with the invention showing the relative location on the tube of two mounting flanges.

In the drawings, like reference numerals refer to like parts.

Referring to the drawings there is shown a flexible tube 1, having a flange 2 on one side thereof, as shown for example in Fig. 1, or with flanges 2 on both sides as illustrated in Fig. 5. The tubes of Figs. 1 to 5 are produced by a weaving process which produces a seamless tube having a mounting flange on at least one side of the tube, the flange being obtained by the manner in which the weaving of the weft thread is performed. As can be seen in Figs. 1 to 4, in the course of the weaving process the weft thread 7 passes not only the warp threads 3 which form the wall of the tube 1 but also through the warp threads 3 which form the mounting flange 2. The mounting flange 2 is thereby firmly joined to the rest of the tube 1. This technique can be applied on any weaving loom irrespective of the weave and thickness of the yarn.

The flexible tube of textile material of Fig. 1 has a mounting flange 2 which has a greater average number of warp threads 3 per unit length than the wall of tube 1. The tube illustrated in Fig. 2 is one in which the yarn used as the warp threads in the mounting flange has a greater diameter than the yarn used to form the wall of the tube. In the tube of Fig. 3, a firmer weave has been used, such as a leno weave or binding warp weave. In the tube of Fig. 4 the increased number of warp threads per unit length is shown extending both into the mounting flange 2 and the tube wall on each side of the mounting flange.

In each case, the flexible tube obtained has an improved resistance to stresses imposed upon it by the material conveyed through the tube or by the mounting elements subsequently attached to the mounting flange.

Claims

1. A flexible tube of textile material for conveying air or gas, provided with a longitu dinal mounting flange formed of a single layer of woven material which is formed by the weave of the weft thread of the material which forms the wall of the tube, the flange serving to receive mounting elements and being integral with both of the portions of the wall of the tube from which it extends, and wherein the average number of warp threads per unit length in the mounting flange is greater than the average number of warp threads per unit length in the wall of the tube, and/or the yarn used for the warp threads of the mounting flange has a greater diameter than the yarn used for the warp threads of the wall of the tube, and/or the yarn used for the warp threads of the mounting flange has a greater tensile strength than the yarn used for the warp threads of the wall of the tube, and/or the region of the intersection of the mounting flange and the wall of the tube is woven with a firmer weave than the remainder of the tube, the said mounting flange thereby having an improved resistance to mechanical stresses.

2. A flexible tube according to Claim 1, wherein the number of warp threads in the mounting flange is 20-30% greater than the number of warp threads in the wall of the tube.

3. A flexible tube according to Claim 1, wherein the number of warp threads in the mounting flange is 30-50% greater than the number of warp threads in the wall of the tube.

4. A flexible tube according to Claim 1, wherein the number of warp threads in the mounting flange is at least 50% greater than the number of warp threads in the wall of the tube.

5. A flexible tube according to any one of the preceding claims, wherein the diameter of the warp threads used in the mounting flange is 20-30% greater than the diameter of the warp threads used in the wall of the tube.

6. A flexible tube according to any one of Claims 1 to 4, wherein the diameter of the warp threads used in the mounting flange is 30-50% greater than the diameter of the warp threads used in the wall of the tube.

7. A flexible tube according to any one of Claims 1 to 4, wherein the diameter of the warp threads used in the mounting flange is at least 50% greater than the diameter of the warp threads used in the wall of the hose.

8. A flexible tube according to any one of the preceding claims, wherein the yarn of greater tensile strength is an aramide.

9. A flexible tube according to any one of Claims 1 to 8, wherein the yarn of greater tensile strength is a glass-fibre.

10. A flexible tube according to any one of the preceding claims, in which the mounting flange further includes yarns having good electrical conductivity.

11. A flexible tube according to Claim 10, wherein the electrically conductive yarn comprises metal fibres.

12. A flexible tube according to Claim 10, wherein the electrically conductive yarn comprises carbon fibres.

13. A flexible tube according to Claim 10, wherein the electrically conductive yarn comprises boron fibres.

14. A flexible tube according to any of Claims 10 to 13, wherein the electrically conductive yarn also comprises textile fibres.

15. A flexible tube according to any one of the preceding claims, wherein both the mounting flange and regions of the tube wall in the vicinity of the intersection of the tube wall with the mounting flange have an average number of warp threads per unit length which is greater than the average number of warp threads in the remainder of the tube wall.

16. A flexible tube according to Claim 16, wherein the said regions having an increased number of threads extend at least 5 cm into each of the tube wall and the mounting flange.

17. A flexible tube according to Claim 16, wherein the said regions extend 2 cm into each of the tube wall and the mounting flange.

18. A flexible tube according to any one of the preceding claims, wherein the firmer weave is a leno weave or a binding warp weave.

19. A flexible tube according to Claim 18, wherein the firmer weaver is a semi-looping weave.

20. A flexible tube according to Claim 1, substantially as hereinbefore described with reference to, and as illustrated in, the accompanying drawings.