WO2007027089A2

WO2007027089A2 - Tube capable of being coupled

Info

Publication number: WO2007027089A2
Application number: PCT/NL2006/000442
Authority: WO
Inventors: Arno Van Mourik; Marcus Antonius Ivonne Kremers; Guido Michael Massaro
Original assignee: Airborne Development B.V.
Priority date: 2005-08-31
Filing date: 2006-08-31
Publication date: 2007-03-08
Also published as: WO2007027089A3; NL1029842C2

Abstract

A tube (1) capable of being coupled, comprising a tube part (2) having a synthetic circumferential wall (3) which is provided, adjacent at least one extremity of the tube part, with a synthetic thickening (5) integrated into the circumferential wall and extending radially outwards with a first clamping surface (6) , further comprising a coupling ring (7) provided at the location of the side of the thickening remote from the extremity so as to be axially slideable around the circumferential wall, which coupling ring is provided with a second clamping surface (8) for cooperation with the first clamping surface. The invention also relates to a method for manufacturing a tube capable of being coupled, wherein a coupling ring is slid around a synthetic circumferential wall of a tube part and wherein, then, on the outer circumference of the circumferential wall, a synthetic thickening is formed for cooperation with a coupling ring.

Description

Title: Tube capable of being coupled

The invention relates to a tube capable of being coupled, comprising a tube part having a synthetic circumferential wall.

Due to developments in material and production techniques, tube parts having a synthetic circumferential wall, such as composite tubes whose circumferential walls consist, at least partly, of fiber reinforced synthetic material, are more and more frequently employed in uses with relatively high pressures and/or relatively high mechanical loads.

A problem occurring with such tube parts is the coupling of the tube parts to each other or to other objects, such as tools or feed or discharge parts, without reducing the pressure resistance or the mechanical resistance of the configuration.

The object of the invention is a tube capable of being coupled, with which this drawback can be prevented. The object of the invention is in particular a tube capable of being coupled, whose parts effecting the coupling are of simple and reliable construction.

To that end, the invention provides a tube capable of being coupled, comprising a tube part having a synthetic circumferential wall which is of uninterrupted design in circumferential direction adjacent at least one extremity of the tube part, and which is provided with a synthetic thickening integrated into the circumferential wall and extending radially outwards with a first clamping surface, further comprising a coupling ring provided at the side of the thickening remote from the extremity so as to be axially slideable around the circumferential wall, which coupling ring is provided with a second clamping surface for direct cooperation with the first clamping surface. Through the provision of a thickening integrated into the circumferential wall and extending radially outwards, the coupling forces can be reliably transmitted via the coupling ring to the circumferential wall of the tube part. Via the clamping surfaces cooperating directly during use, i.e. being in contact during use, tensile forces and torque can be transmitted to the circumferential wall by means of the thickening through sliding. As the circumferential wall has an uninterrupted design in circumferential direction adjacent the extremity, it can absorb the clamping force without significantly bouncing inward in radial direction.

What is achieved through the use of a thickening integrated into the tube, for instance a thickening which is provided during the production process of the tube itself, is that the thickening can absorb as many forces as the tube itself. By designing the coupling ring and/or thickening in one piece in circumferential direction, the clamping force can be increased. Further, the sealing of the coupling can be designed to be highly reliable.

It is preferred that the clamping surfaces are uninterrupted in circumferential direction, and that they are designed as cooperating wedge faces.

In an elegant manner, the tube capable of being coupled is manufactured by sliding the coupling ring around the synthetic circumferential wall of the tube part and by then forming, on the outer circumference of the circumferential wall, a synthetic thickening for cooperation with the coupling ring.

In an advantageous manner, the tube capable of being coupled further comprises a locking ring for attachment to the coupling ring. By providing the locking ring with an auxiliary clamping surface for cooperation with an end face of the tube part, the transmission of forces and the sealing of the coupling can be further ensured. In particular, pressure forces can be transmitted to the circumferential wall via the auxiliary clamping surface.

The invention also relates to a method for manufacturing a tube capable of being coupled.

Further advantageous embodiments of the invention are represented in the subclaims. The invention will be further elucidated on the basis of an exemplary embodiment which is represented in a drawing.

In the drawing:

Fig. 1 shows a schematic cross-section of a tube part having a synthetic circumferential wall;

Fig. 2 shows the tube part of Fig. 1, while a coupling ring is provided so as to be axially slideable around the circumferential wall;

Fig. 3 shows the tube part of Fig. 2, while at an extremity of the tube part a synthetic thickening extending radially outwards is integrated into the circumferential wall of the base part;

Fig. 4 shows the tube part of Fig. 3, while the coupling ring is attached to a locking ring such that a first clamping surface on the thickening cooperates with a second clamping surface of the coupling ring and that an end face of the tube part cooperates with an auxiliary clamping surface of the locking ring; and

Figs. 5A-D show a number of schematic cross-sections of an alternative embodiment of the tube part of Fig. 4.

The Figures are only schematic representations of a preferred embodiment of the invention, which is given by way of non-limitative exemplary embodiment. In the Figures, identical or corresponding parts are represented with the same reference numerals.

Referring to the Figures, in particular Figure 4, a tube capable of being coupled 1 is shown therein. The tube capable of being coupled 1 comprises a tube part 2 having a synthetic circumferential wall 3. Adjacent the extremity, the circumferential wall is of continuous design in circumferential direction, i.e., is not interrupted.

Adjacent an extremity 4 of the tube part, the synthetic circumferential wall 3 is provided with a synthetic thickening-forming thickening 5, extending radially outwards. The thickening is uninterrupted in circumferential direction of the circumferential tube wall. The thickening 5 is integrated into the outside surface 14 of the circumferential wall 3. The synthetic thickening 5 is provided with a first clamping surface 6.

The tube capable of being coupled 1 further comprises a coupling ring 7 provided at the location of the side of the thickening 5 remote from the extremity 4 so as to be axially slideable around the circumferential wall 3. The coupling ring 7 is provided with a second clamping surface 8 for cooperation with the first clamping surface 6. In this exemplary embodiment, the coupling ring 7 is designed from metal, but can, naturally, also be manufactured from another material. In circumferential direction, the coupling ring 7 is designed in one piece.

The thickening 5 is integrally formed with the circumferential wall 3. As will be further elucidated hereinbelow, the thickening 5 comprises fiber material impregnated with synthetic resin, wound around the circumferential tube wall 3. In this exemplary embodiment, the thickening 5 is a thickening that is formed by winding a strip of fiber material impregnated with thermoplastic plastic, a so-called tape, around the circumferential tube wall while heating and pressing-on. The material of the tape is fused with the material of the circumferential wall 3. Naturally, also, a thermosetting material can be used. The first clamping surface 6 is of continuous design in circumferential direction. In this exemplary embodiment, the first clamping surface 6 has undergone a removing process with the aid of a removing machine for realizing good dimensional and shape tolerances.

The first clamping surface 6 is designed so as to be complementary to the second clamping surface 8, which is also uninterrupted in circumferential direction. The first clamping surface 6 is designed as a wedge face inclining upwards to the extremity 4 of the tube part 2. During use, the clamping surfaces 6, 8 cooperate directly. Here, the clamping surfaces directly contact each other. The tube capable of being coupled 1 further comprises a locking ring 9 for attachment to the coupling ring 7. The locking ring 9 is provided with an auxiliary clamping surface 10 for cooperation with an end face 11 of the tube part 2, preferably with at least a part of the end face of the circumferential wall 3 and, optionally, at least a part of the end face of the thickening of the tube part 2.

It is preferred that the locking ring 9 and the coupling ring 7 are detachably connected via a biased connection, for instance via the screw thread connection 12 shown, or by a bolt connection to a flange. Through the provision of a biased connection, clearance can be avoided and torque can be transmitted via friction. It is preferred that the auxiliary clamping surface 10 is also of continuous design in circumferential direction.

During use, the locking ring 9 can form the joining piece to the coupling ring 7 of a subsequent tube part 2 but can, naturally, also form part of another object to which the tube 1 is to be connected, such as a tool or an inlet or outlet piece. If desired, the locking ring 9 can further be provided with a counter tube part or support part (not shown) that supports the inner wall 13 of the tube part 2. It is preferred that such a support or counter tube part extends in axial direction from the extremity 4, axially inwards, along the inner wall 13 beyond the cooperating first and second clamping surfaces 6, 7. In this exemplary embodiment, the tube part 2 comprises a single synthetic circumferential wall 3 which is formed from fiber reinforced synthetic material such as a tube wound from fiber strips impregnated with thermoplastic plastic. Such a thermoplastic plastic is, for instance, PE, PP, PA, PEI, PPS, PEKK or PEEK.

The fiber material is, for instance, a mat woven from carbon fibers, aramid fibers or other types of fibers. Naturally, the fiber material can also be non-woven. Also, the fiber material needs not be impregnated in advance, but can also be impregnated during winding. Instead of thermoplastic material, also, a thermosetting material can be used, for instance polyester, vinylester or epoxy resin.

Within this context, a tube part 2 whose circumferential wall is provided with reinforcing fibers is called a composite tube. For the record, it is noted that the synthetic circumferential wall can be wound around an inner tube, for instance an inner tube from thermoplastic material. Naturally, it is also possible that the tube part is built up from several circumferential walls and/or that some circumferential walls are manufactured from other material than synthetic material, for instance when an inner circumferential wall is used. Also, braided or not-braided conductors, such as electricity cables or optic fibers can be included in the circumferential wall of the tube part 2, or in an inner tube.

For the record, it is further noted that it is also possible that the synthetic circumferential wall 3 is formed from non-fiber reinforced synthetic material, for instance when the tube has a single synthetic circumferential wall which has been extruded from thermoplastic material, for instance PE, PP₃ PA, PEI, PPS, PEKK or PEEK.

The thickening 5 is integrated into the synthetic circumferential wall 3. The synthetic material of the thickening 5 and that of the circumferential wall form a whole 3.

With reference to Figs. 2 and 3, the tube capable of being coupled 1 is manufactured by sliding a coupling ring 7 around the synthetic circumferential wall 3 of the tube part 2 and to then form, on the outer circumference 14 of the circumferential wall 3, a synthetic thickening 5 for cooperation with the coupling ring. Here, the thickening 5 can preferably be formed by winding a fiber material impregnated with resin around the circumferential tube wall 3. If desired, the clamping surface of the thickening which cooperates with the coupling ring can be finished by means of, for instance, reduction. Apart from the above-described winding, a thickening can also be integrated into the circumferential wall by, for instance, casting the thickening onto the circumferential wall, by butting the synthetic material of the circumferential wall 3 or by welding or melting the thickening 5 onto the outer surface 14 of the circumferential wall 3.

In Figs. 5 A-D, in a number of schematic cross-sections, an alternative embodiment of the tube capable of being coupled 1 is represented. In this embodiment, both the tube part 2 and the locking ring 9 are provided with a conductor 15, 16, for instance an electric conductor or an optic fiber. During provision of the locking ring 9, first, the conductors 15, 16 are coupled to form the situation as shown in Fig. 5B. Then, the connected electric conductors 15, 16 are wound together as is represented in, for instance, Fig. 5C. As an alternative, conductors 15, 16 can be connected via a connector or a clamping tube. Thereupon, as is represented in Fig. 5D, a spacer 17 is placed so that a cavity 18 is defined in which the electric conductors 15, 15 can be accommodated in a protected manner. The remaining steps of the manufacture of a tube capable of being coupled 1 can be identical. In Fig. 5 this is illustrated through the representation of the coupling ring 7 in already attached condition. It will be clear that the invention is not limited to the exemplary embodiment described here, but that many variants are possible. Further, if desired, sealing rings may be provided adjacent the clamping surfaces and the auxiliary clamping surfaces. Further, the cooperating clamping surfaces can have a different shape, for instance a multi-stage shape. The clamping surfaces can also be interrupted in circumferential direction.

Such variants will be clear to the skilled person and are understood to lie within the range of the invention as set forth in the following claims.

Claims

1. A tube capable of being coupled, comprising a tube part having a synthetic circumferential wall which, adjacent at least one extremity of the tube part, is designed to be uninterrupted in circumferential direction, and which is provided with a synthetic thickening integrated into the circumferential wall and extending radially outwards with a first clamping surface, further comprising a coupling ring provided at the location of the side of the thickening remote from the extremity so as to be axially slideable around the circumferential wall, which coupling ring is provided with a second clamping surface which, during use, cooperates directly with the first clamping surface.

2. A tube capable of being coupled according to claim 1, wherein the first clamping surface is uninterrupted in circumferential direction.

3. A tube capable of being coupled according to claim 1 or 2, wherein the thickening is designed in one piece in circumferential direction.

4. A tube capable of being coupled according to any one of claims 1 — 3, wherein the coupling ring is designed in one piece in circumferential direction.

5. A tube capable of being coupled according to any one of the preceding claims, wherein the thickening comprises fiber material impregnated with synthetic resin wound around the circumferential tube wall.

6. A tube capable of being coupled according to any one of the preceding claims, wherein the first clamping surface is finished by means of a reducing operation.

7. A tube capable of being coupled according to any one of the preceding claims, wherein the contact surfaces are formed so as to be complementary.

8. A tube capable of being coupled according to any one of the preceding claims, wherein the first clamping surface is designed as a wedge face inclining upwards to the extremity of the tube part.

9. A tube capable of being coupled according to any one of the preceding claims, further comprising a locking ring for attachment to the coupling ring.

10. A tube capable of being coupled according to claim 9, wherein the locking ring is provided with an auxiliary clamping surface for cooperation with an end face of the tube part.

11. A tube capable of being coupled according to claim 9 or 10, wherein locking ring and coupling ring are detachably connected, preferably via a screw thread connection.

12. A tube capable of being coupled according to any one of the preceding claims, wherein locking ring and coupling ring are connected under a bias.

13. A tube capable of being coupled according to any one of the preceding claims, wherein, between thickening and locking ring, a spacer is provided for forming a cavity.

14. A tube capable of being coupled according to claim 13, wherein, in the cavity, a conductor is accommodated.

15. A tube capable of being coupled according to any one of the preceding claims, wherein the circumferential wall is manufactured from fiber reinforced synthetic material.

16. A tube capable of being coupled according to any one of the preceding claims, wherein the bearing parts of the tube part are manufactured from synthetic material or fiber-reinforced synthetic material.

17. A method for manufacturing a tube capable of being coupled, wherein a coupling ring is provided around a synthetic circumferential wall of a tube part so as to be slideable, and wherein, then, on the outer circumference of the circumferential wall, a synthetic thickening is formed for cooperation with a coupling ring.

18. A method according to claim 17, wherein the coupling ring is slid in axial direction around the circumferential wall.

19. A method according to claim 17 or 18, wherein the thickening is formed by winding fiber material impregnated with resin around the tube circumferential wall.

20. A method according to any one of claims 17 - 19, wherein, by means of a reducing operation, the thickening is provided with a clamping surface.