GB2278176A

GB2278176A - Flexible hose

Info

Publication number: GB2278176A
Application number: GB9407348A
Authority: GB
Inventors: Janos Kertesz
Original assignee: Rasmussen GmbH
Current assignee: Norma Germany GmbH
Priority date: 1993-05-07
Filing date: 1994-04-14
Publication date: 1994-11-23
Anticipated expiration: 2014-04-14
Also published as: FR2704926B1; DE4315175A1; GB2278176B; GB9407348D0; FR2704926A1; JP2611658B2; JPH06331080A; DE4315175C2

Description

2278176 1 FLEXIBLE PIPELINE The invention relates to a flexible pipeline.

Such a pipeline may comprise a length of corrugated pipe made of plastics material with push-fit connector fittings fastened to end sections of the corrugated pipe.

With such a pipeline there is the risk that the corrugated pipe stretches because of the pressure of fluid conducted through it, particularly in its longitudinal direction, so that it takes up an excessive amount of space and/or the fluid pressure drops, which in many cases is undesirable.

It is known from Patent Specification US-Re 20 583 to surround a metal corrugated pipe with a metal weave. In order to fasten the metal weave to the end sections of the pipe, a ring of deformable material is fixed to each end section of the metal weave, and, by means of a cap nut pushed onto the ring, a flange of which lies against one end of the ring, is screwed onto a sleeve having an external thread, which lies against the other end of the ring. The ring is compressed axially as the cap unit is screwed on, so that it presses the metal weave radially against the corrugated pipe. A metal corrugated pipe is less flexible, less resistant to corrosion and requires more energy to manufacture than a corrugated pipe made of plastics material. Additionally, the method of fastening the woven cover to the corrugated pipe is complex.

A metal hose is known from Patent Specification DE 974 608, made of a helically wound metal strip with a heat-shrunk hose of thermoplastic material, such as PVC. At the end of the pipe formed in this way, between the metal and the plastics hose, a pipe connection piece is inserted, onto which the plastics hose is fastened by shrinking. In addition, the end section shrunk onto the pipe connection fitting of the plastics hose can be clamped by means of a beaded sleeve or hose clip. A metal hose of this type is also less resistant to corrosion, less flexible and more expensive to manufacture than a plastic hose. In order to recycle the pipeline made from metal and plastic hose, these must first be separated, in a costly manner.

This is also the case with the beaded sleeves or clips possibly used in addition.

According to the invention there is provided a flexible pipeline 2 comprising a length of corrugated pipe of plastics material and pushfit connection pieces fastened to end sections of the corrugated pipe, in which the corrugated pipe is surrounded by a cover of fibre weave, which is tension-resistant in the axial direction of the corrugated pipe, which cover, in the region of the end sections of the corrugated pipe is contact pressed by means of a respective clamping sleeve onto the end section concerned, and the clamping sleeves of thermoplastic material are formed by injection around the cover and the push-fit connector fittings.

Such a flexible pipeline can largely retain its shape regardless of internal pressure, and can be easily manufactured. Thus the cover ensures the maintenance of the shape of the corrugated pipe, even under very high internal pressure of up to 60 bar. Moreover, the pipeline remains flexible, in order to be able to adapt to spatial conditions. In addition, as the clamping sleeve is manufactured, a secure material connection is formed between the cover and the push-fit connector fittings.

It is preferably ensured that the push-fit connector fittings are inserted in the end sections of the corrugated pipe and the clamping sleeves press the end secions against the push-fit connector fittings.

This configuration leads to a particularly secure connection between the cover, corrugated pipe and push-fit connector fittings, as the clamping sleeves cool after injection around the cover, and therefore contract. 25 The thermoplastic material of the clamping sleeves can penetrate the fibre weave of the cover in its softened state during injection and at the same time enclose the push-fit connector fittings, so that the clamping sleeves materially connect the cover, the corrugated pipe and the push-fit connector fittings. 30 The corrugated pipe is preferably manufactured from a polyolefin. This material can easily be re-used. The corrugated pipe is preferably composed of a thermoplastic elastomer, so that it is particularly pliable. It is also convenient if the corrugated pipe is a multi-layered pipe, at least one layer of which is manufactured from a thermoplastic elastomer. Corrugated pipes of this kind can withstand particularly high pressures, and. with a suitable choice of materials, can withstand 3 chemically corrosive fluids and high temperatures.

It is particularly convenient if the corrugated pipe is manufactured from a fluoroplastic, particularly PVDF (polyvinylidene fluoride) or ETFE (an ethylene/ tetraf luoride ethylene copolymer). A material of this type is particularly suitable for recycling.

The corrugated pipe can also be a multi-layered pipe with one layer manufactured from polyamide. In this case too, the corrugated pipe withstands high pressures and, with a suitable choice of materials for the remaining layers, also corrosive fluids and high temperatures.

The corrugated pipe, the push-fit connector fittings, the cover and the clamping sleeves are preferably manufactured from the same material. When the materials from such a pipeline are re-used, it is then unnecessary to dismantle the pipeline and to sort the components according to their different materials.

Then, the cover can be surrounded by a thermoplastic covering layer, which forms additional mechanical protection against impact stress or corrosive fluids.

The invention is diagrammatically illustrated by way of example in the accompanying drawing which shows a side view of a flexible pipeline according to the.invention, partially in section.

The pipeline consists of a corrugated pipe 1, shown partly in section and cut away, made from a thermoplastic elastomer, preferably fluoroplastics, particularly PVDF or ETFE or polyamide, a cover 2 surrounding the corrugated pipe 1 and in the form of a weave with high tensile strength, particularly axially, two clamping sleeves 3 and push- fit connector fittings 4, inserted into the end sections, which are initially smooth, of the corrugated pipe 1. In each of the pushfit connection pieces 4 a ring 5 with radially elastically spreadable spring arms 6 and sealing rings 7 are fastened. The parts 4 to 7 form, on each end of the pipeline, a push-fit connection into which a pipe connection fitting 8 or the like with an annular bulge can be tightly inserted into the snap f itting and in this way can be coupled. The end sections of the push-fit connector fittings 4 introduced into the end sections of the corrugated pipe 1 are provided with ribs 9 for axial securing.

Alternatively, the corrugated pipe 1 can be manufactured from a polyamide.

4 The clamping sleeves 3 are also composed of a thermoplastic material. Advantageously the corrugated pipe 1, the cover 2, the clamping sleeves 3 and the push-fit connector fittings 4 are manufactured from the same thermoplastic material. The clamping sleeves 3 are formed by simultaneous injection around the cover 2 and the push-fit connector fittings 4 and also penetrate the weave of the cover 2 as far as the corrugated pipe 1. In this way, this results on the one hand in a material connection between the clamping sleeves 3 and the corrugated pipe 1 and on the other hand a material connection between the materials of all four parts 1, 2. 3 and 4. This connection is not only particularly secure, but also extremely tight. When the pipeline is used as a fuel pipe, the known permeation problems precisely at the most critical connection area can thereby be reduced to a minimum. Also when the pipeline is used as a cooling water hose, the connection is clearly more reliable than currently known types of connection.

Altogether, the pipeline can withstand high internal pressure of up to 60 bar, without the corrugated pipe 1 lengthening or widening. When the same materials are used for all the parts 1 to 4, particularly polyamide, the pipeline can be recycled without the parts thereof having to first be separated and sorted according to their different materials.

Otherwise than in the embodiment shown, the cover can be surrounded by a thermoplastic covering layer. In this case, the clamping sleeves 3 can be composed of a cohesion-modified plastics material, which. when injected, performs a weld connection of the materials of the corrugated pipe 1 and the push-fit connector fittings 4 if the corrugated pipe 1 and the push-fit connector fittings 4 are composed of different plastics materials, for example, on the one hand of PA and on the other of PE.

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Claims

1. A flexible pipeline comprising a length of corrugated pipe of plastics material and push-fit connection pieces fastened to end sections of the corrugated pipe, in which the corrugated pipe is surrounded by a cover of fibre weave, which is tension- resistant in the axial direction of the corrugated pipe, which cover, in the region of the end sections of the corrugated pipe is contact pressed by means of a respective clamping sleeve onto the end section concerned, and the clamping sleeves of thermoplastic material are formed by injection around the cover and the push-fit connector fittings.

2. A flexible pipeline according to claim 1, in which the push-fit connector fittings are inserted into the end sections of the corrugated pipe and the clamping sleeves press the end sections against the pushfit connector fittings.

3. A flexible pipeline according to claim 1 or claim 2, in which the clamping sleeves materially connect the cover, the corrugated pipe and the push-fit connector fittings.

4. A flexible pipeline according to any one of claims 1 to 3, in which the corrugated pipe is manufactured from a polyolefin.

5. A flexible pipeline according to any one of claims 1 to 4, in which the corrugated pipe is manufactured from a thermoplastic elastomer.

6. A flexible pipeline according to any one of claims 1 to 5. in which the corrugated pipe is a multi-layered pipe, at least one layer of which is manufactured from a thermoplastic elastomer.

7. A flexible pipeline according to any one of claims 1 to 5, in which the corrugated pipe is manufactured from a fluoroplastics material, particularly PUF or EFTE.

8. A flexible pipeline according to claim 7, in which the 6 fluoroplastics material is PVDF.

9. A flexible pipeline according to claim 7. in which the fluoroplastics material is EFTE.

10. A flexible pipeline according to any one of claims 1 to 6, in which the pipeline is a multi-layered pipe, at least one layer of which is manufactured from a fluorothermoplastics material.

11. A flexible pipeline according to any one of claims 1 to 5, in which the corrugated pipe is a multi-layered pipe, at least one layer of which is manufactured from polyamide.

12. A flexible pipeline according to any one of claims 1 to 11, in which the corrugated pipe, the push-fit connector fittings, the cover and the clamping sleeves are manufactured from the same material.

13. A flexible pipeline according to any one of claims 1 to 12, in which the cover is surrounded by a thermoplastic covering layer.

14. A flexible pipeline substantially as hereinbefore described and illustrated with reference to the accompanying drawings.

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