GB2183000A

GB2183000A - Tube bundle

Info

Publication number: GB2183000A
Application number: GB08626987A
Authority: GB
Inventors: Horst Vogelsang
Original assignee: Ernst Vogelsang GmbH and Co KG
Current assignee: Ernst Vogelsang GmbH and Co KG
Priority date: 1985-11-16
Filing date: 1986-11-12
Publication date: 1987-05-28
Also published as: NO165737C; AT396533B; NO864543L; CH673914A5; DK163467C; NL8602907A; GB2183000B; FI82134B; SE8604897L; FR2590417A1; FI864643A0; FR2590417B1; CH673359A5; DK545186D0; NO864543D0; SE8604897D0; SE464936B; NO165737B; ATA285286A; BE905749A

Abstract

A tube system e.g. as cable conduit comprises a plurality of plastics tubes (1) joined together by integral spacers (2) formed as foil hinges so that the tube system can be wrapped about a centre-point (3) to form a bunch by elastically deforming the foil hinges, and the individual tubes (1) have integral core elements (4) which assemble into a stabilising core (5) in the wrapped bunch. The core elements (4) are preferably ridge-shaped in cross- section and hollow, so with the preferred four tubes (1) in the system the core elements (4) have a ridge angle of 90 DEG and their flanks (6) run tangentially into the associated tube walls (7). The core elements (4) may be slit or gapped transversely to facilitate bending. The core elements (4) may be bonded, welded or interlocked together e.g. by slits and headed members. An outer tape may be wrapped about the assembled tube system. The flanks (6) may be arcuate to accommodate a centre cable. <IMAGE>

Description

SPECIFICATION Integrated plastics conduit tubes This invention relates to a tube system of the type comprising a plurality of plastics tubes joined together by integral spacers formed as foil hinges so that the tube system can be wrapped about a centre-point to form a bunch by elastically deforming the foil hinges.

Tube systems of this type are used as cable conduits, such as those commonly adopted for radio, television and data transmission links. The tube systems are made in one piece by the extrusion of synthetic thermoplastic materials, and the latter are adapted so that the tube system can be both wrapped as just described and laid to form curved conduits. One common material is polyethylene.

Another can be polyvinyl chloride.

In a known product of this type (cf. the Vogelsang brochure entitled "The Vogelsang M4 Multi-purpose Conduit System", May 1985), the individual tubes have plain cylindrical surfaces making tube to tube contact towards the centre of the bunch. The resulting bunch is not immediately stable after wrapping. The known systems have proved sound, provided the bunch is drawn into a cable duct in the form of another plastics tube, for example, in which it is stabilised with the further aid of locating bands or shrunk-on end caps. The known product can of course also be laid in a trench, but it is then lacking in stability.

The object of the invention is to provide an improved tube system of the type initially defined so that the wrapped bunch is stable in shape, more particularly capable of retaining its shape when laid in a trench prepared by the virtually automatic mechanical method of plough trenching.

According to the present invention, the individual tubes have integral core elements which assemble into a stabilising core in the wrapped bunch. The core elements can be slit transversely to their length or provided with gaps to lower their resistance to bending.

Various possibilities for modification and shaping are within the scope of the invention.

For instance, the core elements can be formed as hollow profile sections integral with the tubes and adpated to face towards the centre of the bunch. Preferably, the core elements are ridge-shaped in cross-section, in which case the flanks of the ridges lie face to face in the core of the bunch.

The invention places no limitations on the number of tubes forming the tube system. In practice, three to six tubes usually suffice for the applications described above, and four tubes are preferred. The tubes can have equal or differing diameters. The normal external diameters for the individual tubes lie in the range 30 to 60 mm. The breadth of the spacers is adapted to the bunch geometry to be obtained by wrapping the tube system. Preferred embodiments of the invention utilise four tubes of the same cross-section, their axes forming a square in the bunch crosssection, the core elements having a ridge angle of 90', and the flanks of the ridges running tangentially into the associated tube walls.

The tubes in the tube system of the invention lie in a tight bunch, in contact directly and through the core elements. However, they are preferably clamped together. This can be effected in various ways, for example by banding or wrapping with plastics or metallic tapes. If banding is adopted, the distances between successive banding points can be several metres. It is within the scope of the invention to bond the flanks of the ridges to each other in the bunch, i.e., to apply an adhesive. One can use electric welding apparatus or compound masses and/or conventional adhesives. However, the flanks of the ridges can also carry a self-adhesive facing and be joined together thereby in the bunch. Alternatively or in addition, the flanks of the ridges may carry interlocking members by which the bunch is held together.

Another preferred embodiment of the invention is characterised in that the stabilising core has a circular-section hollow space at its centre, formed by the core elements having corresponding arcuate recesses. An extra cable can be drawn into the central holow space or inserted during plough trenching.

The accruing advantages are to be seen in that in the tube system of the invention the tubes are assembled into a bunch of stable shape with the aid of the core elements. The shape of the bunch is automatically stabilised, even when laid in a trench by plough trenching or like means. Nevertheless, the tube system in its bunched shape can still be drawn into a cable duct as before. Manufacture is straightforward and involves simple extrusion.

However, the shape of the bunch can also be fixed. As already mentioned, this can be effected by simple banding with a banding strip, which can be tensioned. According to another aspect of the invention, however, the end tubes in the tube system have closure webs which come together in the bunch and are joined to each other, which closure webs may be continuations of the outer flanks of ridges on the end tubes of the tube system. The closure webs can be elastically deformable, thus facilitating closure. The closure webs on one side may have slit-shaped openings while those on the other side have mushroomshaped locking members which fit therein.

A number of embodiments of the invention will now be described, purely by way of example, with reference to the accompanying drawings, in which: Figure 1 is a cross-section through a tube system in accordance with the invention; Figure 2 shows the system of Figure 1 wrapped to form a bunch; Figure 3 is a perspective view of part of the tube system of Figure 1; Figure 4 corresponds to Figure 2, but shows another embodiment of the invention; Figure 5 corresponds to Figure 2, but shows means to hold the wrapped tube system together; Figure 6 is a perspective view, corresponding to part of the tube system of Figure 5; Figure 7 corresponds to Figures 2 and 4, but shows yet another embodiment of a tube system in accordance with the invention; Figure 8 shows the tube system of Figure 7, opened out flat and seen on a smaller scale than Figure 7;; Figure 9 is a corresponding view to Figure 8 of yet another embodiment; Figure 10 shows a modification of the tube system of Figure 4; and Figure 11 shows a modification of the tube system of Figure 5.

Each of the tube systems shown in the drawings consists of a plurality of plastics tubes 1 joined together by integral spacers 2 formed as foil hinges 2. Consequently, the tube system can be wrapped about a centrepoint 3 to form a bunch by elastically deforming the foil hinges 2. This is made clear by comparing Figures 1 and 2, for example. The tube systems are used as cable conduits.

In accordance with the invention, the individual tubes 1 have integral core elements 4 which assemble into a stabilising core 5 in the wrapped bunch. In the preferred embodiments the core elements 4 are formed as hollow profile sections integral with the tubes 1 and are ridge-shaped in cross-section, the flanks 6 of the ridges lying face to face in the stabilising core 5 of the bunch.

In the embodiments shown, each tube system has four tubes 1 of equal crosssection, their axes forming a square in the bunch cross-section. Accordingly, the preferred core elements 4 have a ridge angle a of 90 , and the flanks 6 of the ridges run tangentially into the associated tube walls 7 (see also Figure 3).

For the sake of clarity in Figure 2 there are gaps between the adjacent core elements 4, but it will be evident that in practice these elements fit closely together. It will be appreciated from Figure 2 that the flanks 6 of the ridges in the bunch can be bonded together adhesively. They could have a self-adhesive facing for this purpose, but this is not shown.

Figure 4 shows an embodiment in which the stabilising core 5 has a circular section hollow space 8 at its centre formed by the core elements 4 having corresponding arcuate recesses 9. An extra cable can be inserted into the hollow space 8.

One can also provide means to hold the wrapped tube system together, which can take the form shown in Figures 5 and 6. It will be seen in Figure 5 that the bunch of tubes contains a stabilising core 5 which supports the tubes 1 in the bunch. In this respect, the arrangement conforms to that in Figures 1 to 4. However, it will also be seen that the end tubes 1 in the tube system have closure webs 10, which come together in the bunch and are joined to each other, being elastically deformable. Figure 6 more particularly shows that the closure webs 10 on one side have slit-shaped openings 11, and those on the other side have mushroom-shaped locking members 12 which fit therein.

It will also be evident that the closure webs 10 could be joined together by welding and/or adhesive bonding. Thus, the opposing faces of the closure webs 10 could carry selfadhesive facings.

To facilitate laying of the wrapped tube system round bends, the slit-shaped openings 11 are substantially longer than the ridge-shaped locking members 12. It is within the scope of the invention to serve the same purpose by slitting the core elements 4 transversely to their length or by providing longer openings in the core elements, both being illustrated in Figure 6. These features lower the resistance to bending. The same purpose is served when wrapping the tube system round a drum. It will be evident that these features can also be confined to specified areas, i.e., where it is required to lay down a bend.

As Figures 7 and 8 or Figure 9 indicate, the core elements 4 could alternatively be attached to the foil hinges 2. The core elements again assemble in the bunch to form a stabilising core 5, i.e., which stabilise the bunch of tubes, particularly when it is clamped together.

Clamping can be effected by the banding 14 shown in Figure 7 and/or by means of the closure webs 10, openings 11 and locking members 12 previously described.

Each of the core elements 4 shown in Figures 7 and 8 has a unitary connection web 13 attached to the spacer 2. In the embodiment shown in Figures 7 and 8, the core elements 4 are formed as hollow sections which fit together at interfaces 15. It will be seen that these stabilising members 4 are generally square in cross-section but convexly curved to face the tubes. It will be evident that the interfaces 15 in the bunch of tubes can be bonded together adhesively.

When the tube system of Figure 9 is wrapped to form a bunch, it produces a sta bilising core 5 having a circular section hollow space 8 about its centre 3. The core elements 4 are in fact correspondingly provided with an arcuate cross-section.

Any one of the embodiments shown can be further stabilised. This is illustrated in Figure 10, which shows a modification of Figure 4, and in which additional stabilising elements 16 have been provided between adjacent pairs of tubes 1 and are connected together by the foil hinges 2.

In the embodiment shown in Figure 11, one set of flanks 6 of the core elements 4 have interlocking closure members 17 which pass through slots in the other set of flanks.

Claims

1. A tube system comprising a plurality of plastics tubes joined together by integral spacers formed as foil hinges so that the tube system can be wrapped about a centre-point to form a bunch by elastically deforming the foil hinges, and wherein the individual tubes have integral core elements which assemble into a stabilising core in the wrapped bunch.

2. A tube system as in Claim 1, wherein the core elements are formed as hollow profile sections integral with the tubes and adapted to face towards the centre of the bunch.

3. A tube system as in either of Claims 1 and 2, wherein the core elements are ridgeshaped in cross-section and the flanks of the ridges lie face to face in the core of the bunch.

4. A tube system as in Claim 3, having four tubes of the same cross-section, their axes forming a square in the bunch cross-section, and wherein the core elements have a ridge angle of 900 and the flanks of the ridges run tangentially into the associated tube walls.

5. A tube system as in either of Claims 3 or 4, wherein the flanks of the ridges in the bunch are adhesively bonded to each other.

6. A tube system as in any one of Claims 3 to 5, wherein the flanks of the ridges carrying a self-adhesive facing.

7. A tube system as in any one of Claims 3 to 6, wherein the flanks of the ridges carry interlocking members by which the bunch is held together.

8. A tube system as in either of Claims 1 or 2, characterised in that the stabilising core has a circular section hollow space at its centre formed by the core elements having corresponding arcuate recesses.

9. A tube system as in any one of Claims 1 to 8, wherein the end tubes in the tube system have closure webs which come together in the bunch and are joined to each other.

10. A tube system as in Claim 9, wherein the closure webs are elastically deformable.

11. A tube system as in either of Claims 9 or 10, wherein the closure webs on one side have slit-shaped openings and those on the other side have mushroom-shaped locking members which fit therein.

12. A tube system as in Claim 1, wherein each of the core elements has a unitary connection web attached to the spacer.

13. A tube system as in Claim 12, wherein the core elements are formed as hollow sections which fit together at interfaces.

14. A tube system as in Claim 13, wherein the core elements are convexly curved to face the tubes.

15. A tube system as in any one of Claims 12 to 14, wherein the interfaces in the wrapped bunch of tubes are bonded together adhesively.

16. A tube system as in any one of Claims 12 to 15, wherein the stabilising core has a circular section hollow space at its centre formed by the stabilising members being provided with an arcuate cross-section.

17. A tube system substantially as hereinbefore described with reference to Figures 1 to 3, Figure 4, Figures 5 and 6, Figures 7 and 8 Figure 9 Figure 10, or Figure 11 of the accompanying drawings.