WO1996033365A1

WO1996033365A1 - Cable sheath device

Info

Publication number: WO1996033365A1
Application number: PCT/FR1995/000524
Authority: WO
Inventors: Jean Lepers; André Bernard
Original assignee: Entrepose-Montalev
Priority date: 1995-04-21
Filing date: 1995-04-21
Publication date: 1996-10-24

Abstract

A sheath device for cables, particularly electrical or telecommunication cables, is disclosed. The sheath device includes an outer tube (10) with an axis, a first end (12) and a second end (14); a plurality of ducts (16) with first (18) and second (20) ends, said ducts having substantially the same length as the tube and being arranged therewithin; and a body of tube filling material (24) in which the ducts are embedded, whereby said ducts are maintained in positions that are substantially mutually parallel and parallel to the tube axis. The filling material does not fill the first and second ends of said ducts so that at least the first ends of duct and tube stick out of the first end surface of the filling material body.

Description

SHEATHING DEVICE FOR CABLES

The present invention relates to a sheath device for cables, in particular for electrical or telecommunication cables.

Underground cables, whether electrical, telecommunication or other, are generally laid in the ground, in a gutter, in a gallery, in a well or even in a sheath. Sheathing is generally recommended for road crossings to avoid intervening on the corresponding roadways while allowing cable replacement. Sheathing is also recommended to ensure better protection of cables in a particular site, for example in a nuclear power plant under construction. Finally, the sleeves are recommended to allow the laying of numerous cables in a reduced space. This arrangement is very often used for telecommunication cables. When a large number of cables have to be installed, multi-tubular sheaths (Duck-bank in English) are most often used which are interposed between junction chambers. These multi-tubulars are generally not reinforced when the ground is stable and free from troublesome groundwater. On the other hand, in the case of multi-tubulars in unstable ground or in the case where mechanical protection must be reinforced (importance of short-circuit currents or cables too close to the ground surface), the structure must be reinforced.

In the case of particularly hostile terrains, such as floodplains with aggressive water such as seawater, the durability of the cables is no longer ensured over time due to corrosion. The installation of cathodic corrosion protection is then very difficult and expensive to implement with unsafe results. The mechanical strength of such a linear structure is not ensured, which risks causing the deterioration of the sleeves with the consequence of the entry of water and in the medium or long term the deterioration of the cables.

To overcome these drawbacks, an object of the present invention is to provide a sheath device allowing the installation of a large number of cables which allows on the one hand easy mounting, and on the other hand good mechanical protection. greater than that that is obtained with conventional multitubular tubes and which also makes it possible to conveniently adapt cathodic protection.

To achieve this goal, the cable sheath device is characterized in that it comprises: an external tube having an axis, a first and a second end; a plurality of sleeves having a first and a second end and having a length substantially equal to that of the tube, said sleeves being arranged inside said tube; and a volume of filling material of the tube in which said sleeves are coated, whereby the sleeves are kept substantially parallel to each other and parallel to the axis of the tube, the filling material leaving open the first and second ends of said sleeves, at minus the first ends of said sleeves and said tube projecting from the first end face of the filling volume, whereby said sheath device has at its first end an area devoid of filling material extending inside the tube and around said sheath.

It is understood that, thanks to the provisions of the invention, the sleeves into which the cables are actually introduced are embedded in a mass of filling material such as cement or concrete poured inside the outer tube. This filling provides mechanical protection for the sleeves. The presence of the external tube makes it possible to gather in a single element a plurality of sleeves, which greatly facilitates installation. In addition, preferably, the outer tube is metallic and allows the installation of easy cathodic protection.

According to a preferred embodiment of the invention, the second ends of the tube and the sleeves are arranged substantially in the plane of the second end face of the filling volume and the first ends of the sleeves protrude from the first face of said tube.

Also preferably, the second ends of the sleeves have a portion of enlarged diameter to receive the first ends of the sleeves of the adjacent sheath device. The invention also relates to a method of assembling two sheath devices of the type defined above which is characterized in that it comprises the following steps: there is opposite the first end of one of the sheath devices and the second end of the other sheath device; causing mechanical cooperation of the first end of the tube and the sleeves of the first sheath device with the second end of the tube and the sleeves of the second sheath device; and filling with complementary filling material said zone of the first sheath device devoid of filling material.

Thanks to the method according to the invention, one thus realizes not only the mutual mechanical joining of the inner sleeves and the outer tube but also the continuity of the filling material at the level of the assembly of the tubes, which makes it possible to obtain mechanical protection. constant sheaths.

Other characteristics and advantages of the present invention will appear better on reading the following description of an embodiment of the invention given by way of non-limiting example. The description refers to the appended figures in which:

- Figure 1 is a longitudinal sectional view of the sheath device according to the invention;

- Figure 2 is a section of the sheath device along line II— II of Figure 1;

- Figures 3 to 8 are longitudinal sections of two adjacent sheath devices showing the different stages of the joining of two sheath devices; and

- Figure 9 is a vertical sectional view showing an example of a method of manufacturing the sheath device according to the invention.

Referring first to Figures 1 and 2, we will describe a preferred embodiment of the sheath device. This comprises an external tube 10 which has a first and a second end, respectively referenced 12 and 14. The tube 10 preferably has a length of the order of 10 to 12 meters and depending on the applications its diameter can range from 400 to 1200 mm. The tube 10 is preferably cylindrical and it has an axis XX '. Preferably, this tube is made of steel insulated with a coating of pitch, polyethylene, expoxy, etc. Inside the tube 10 there are internal sleeves 16. In the particular case of FIG. 2, there are four internal sleeves referenced 16a, 16b, 16c and 16d. The number of sleeves of course depends on the amount of cables that must be passed through the sheath devices. Preferably, these sleeves are made of PVC. They have a diameter which can range from 60 to 200 mm. Each sleeve 16 has a first end 18 which protrudes from the end 12 of the tube 10 by a length 11 and a second end 20 which is arranged substantially in the same plane as the second end 14 of the tube 10.

As best shown in Figure 1, the sleeves 16 have a generally cylindrical shape whose axes xx 'are parallel to the axis XX ¹ of the tube 10. The second end 20 of each sleeve has an area 22 of enlarged diameter which is understood that it allows the engagement of the first end 18 of the sheath of the sheath device to be assembled to that which is represented in FIG. 1. The space surrounding the sheaths 16 and disposed inside the tube 10 is filled with a filling material 24 in which the sleeves 16 are thus embedded and immobilized.

As shown in FIG. 2, preferably, the sleeves 16 are regularly distributed inside the tube 10. As shown in FIG. 1, the volume of filling material 24 which consists of lean concrete, cement grout or bentonite or other equivalent materials has a first face 26 which is set back relative to the end 12 of the outer tube, and therefore relative to the ends 18 of the sleeves and a second end face 28 which is substantially in the same plane as the end 14 of the tube 10 and the ends 20 of the sleeves. The end face 26 of the filling volume 24 therefore leaves an empty zone 30 at the first end of the tube 10 inside the tube 10 which surrounds the first ends 18 of the sleeves 16. It can also be seen that the first end 12 of the tube 10 is preferably provided with two guide elements 32 and 34 which make protrusion out of the tube 10 of a length 12 which is greater than the length 11 whose sleeves protrude out of the tube 10. The guide elements 32 and 34 can penetrate as will be explained later in reserved areas 36 and 38 provided at the second end 14 of the tube 10 inside the filling material 24.

FIG. 1 also shows that the tube 10 is provided with a cylindrical ferrule 40 which can slide on the external face 10a of the tube 10. At rest, the ferrule 40 is near the first end 12 of the tube 10. This ferrule 40 preferably comprises two diametrically opposite orifices 42 and 44 whose function will be explained later.

Referring now to Figures 3 to 8, we will describe a preferred method of assembling two sheath devices respectively bearing the references A and B. As shown in Figure 3, firstly, we put the second end 14 of the sheath device B and the first end 12 of the tube of the second sheath device A. The guide elements 32 and 34 of the device A are opposite the reserved zones 36 and 38 of the sheath B. By construction, the second ends 20 of the sleeves 16 of the sheath B are opposite the first ends 18 of the sleeves 16 of the sheath A.

In the next step, the ends of the sheaths A and B are brought together, the approximation being guided by the cooperation of the guide elements 32, 34 and the reserved zones 36, 38. This approximation is carried out until the ends 18 of the sheaths of the sheath A are fully engaged in the enlarged portions 22 of the ends of the sheaths 16 of the sheath B.

As shown in FIG. 5, in this position, there remains a clearance e between the ends of the tubes 10, respectively of the sheath A and of the sheath B. As shown in FIG. 6, the ferrule 40 then slides. until the latter covers the ends of the tubes 10 of the sheaths A and B and the orifices 42 and 44 formed in this ferrule are facing the clearance existing between the ends of the tubes 10. In this position of the ferrule, the ferrule 40 is welded at 46 and 48 to immobilize the latter relative to the tubes. In the next step shown in FIG. 7, the filling 42 is injected with the orifice 42 to fill the zone 30 which was initially devoid of filling material. The second orifice 44 provided in the ferrule serves as a vent during the filling of the zone 30. When this filling is finished, a continuous coating of the sleeves 16 of the sheaths A and B is thus obtained with the filling material without there being any discontinuity between the two sheath devices.

Finally, as shown in FIG. 8, when the filling is completed, the orifices 42 and 44 are closed off by any suitable means.

FIG. 9 illustrates a method of manufacturing the sheath device represented in FIGS. 1 and 2. A horizontal base plate 60 is used, the upper face 60a of which has lugs 62 capable of penetrating the reserves 36, 38 of the end of the outer tube 10. The plate 60 also includes four sleeves 64 protruding from this face and having the spatial arrangement desired by the sleeves 16. These sleeves have a diameter which is conjugated with that of the enlarged ends 22 of the sleeves 16. It is thus possible to put in place the second ends of the sleeves 16 and of the outer tube 10. Then jigs 66 are put in place at different levels to hold the sleeves 16 inside their outer tube in place over their entire length. then fills, using the filling material, the space external to the sleeves 16 and internal to the tube 10 until it reaches the desired level 68. It then suffices to let the filling material set. Next, the base plate 60 is separated from the sheath device thus obtained.

Alternatively, it is possible to provide that the first ends of the outer tube 10 and the sleeves 16 are substantially arranged in the same plane. In this case, it is necessary to provide in the first end of the tube 10 two notches coinciding with the orifices 42 and 44 of the ferrule 40 when the latter is brought into its final position. It should be added that one or more sleeves can be used to circulate a coolant, especially when the power carried in the cables contained in the other sleeves is important.

Claims

1. Cable sheath device, characterized in that it comprises: an external tube (10) having an axis, a first (12) and a second end (14); a plurality of sleeves (16) having a first (18) and a second (20) end and having a length substantially equal to that of the tube, said sleeves being arranged inside said tube; and a volume of filling material (24) of the tube in which said sleeves are coated, whereby the sleeves are held substantially parallel to each other and parallel to the axis of the tube, the filling material leaving open the first and second ends of said sleeves, at least the first ends of said sleeves and said tube projecting from the first end face of the filling volume, whereby said sheath device has at its first end an area devoid of filling material extending to the inside the tube and around said sheath.

2. Sheath device according to claim 1, characterized in that the second ends of the tube (14, 20) and of the sleeves are arranged substantially in the plane of the second end face (28) of the filling volume and in that that the first ends (18) of the sleeves protrude from the first end (12) of said tube.

3. Sheath device according to claim 2, characterized in that said second ends (22) of the sleeves (16) have a portion of enlarged diameter (22) for receiving the first ends (18) of the sleeves of the adjacent sheath device.

4. Sheath device according to any one of the claims

2 and 3, characterized in that said first end of the tube (12) is provided with at least one positioning element (32, 34) projecting from the first end (12) of the tube (16) and able to cooperate with a recess (36, 38) formed at the second end (14) of the tube of the adjacent sheath device, said positioning element protruding from the first end of said tube of length 11 greater than the length 12, the first ends of the sheaths projecting from the first end of the tube.

5. Sheath device according to any one of claims 1 to 4, characterized in that it further comprises a ferrule (40) slidably mounted on the first end of the external face (10a) of the tube, said ferrule being suitable , after sliding, to cover the first end of said adjacent sheath device.

6. Sheath device according to claim 5, characterized in that said ferrule (40) is provided with at least one orifice (42, 44) which, after assembly of two adjacent sheath devices and sliding of said ferrule, opens into the area (30) not occupied by said volume of filling material (24), whereby filling material can be introduced into said area through said orifice.

7. Sheath device according to any one of claims 1 to 6, characterized in that said external tube (10) is made of steel and in that said sleeves (16) are made of plastic material, and in that said filling material (24) is chosen from the group comprising concrete, cement and bentonite.

8. Sheath device according to any one of claims 1 to 7, characterized in that said external tube (10) has a length between 10 and 12 m and a diameter between 400 and 1200 mm.

9. Sheath device according to any one of claims 1 to 8, characterized in that said sleeves (16) are made of PVC.

10. A method of assembling two sheath devices according to any one of claims 1 to 9, characterized in that it comprises the following steps: one has opposite the first end of one of the sheath devices the second end of the other sheath device; causing mechanical cooperation of the first end of the tube and the sleeves of the first sheath device with the second end of the tube and the sleeves of the second sheath device; and filling with complementary filling material said zone of the first sheath device devoid of filling material.