Method and device for installing cables

The invention relates to a method of installing cables in pipes, for cables, by means of installation devices, provided for the purpose of exercising a driving force on the cables. In particular, the invention relates to a method of installing cables by means of installation devices provided with motor and drive wheels, for pushing cables into pipes. The invention also relates to devices for installing cables by using such a method. Such a method and device are known from European Patent EP 0129037.

In the aforementioned European patent, a method and a device for installing cables by means of a combination of propulsive forces are described, a first force being exerted by wheels driven by an engine, and a second force being exerted as a driving force of the motor. of a fluid. The aforementioned patent also mentions the use of several such devices for cable installation over long distances (so-called tandem use).

According to prior art techniques, such as those described in [1], each installation device is directly coupled to a source of pressurized fluid, such as a compressor. That is, as many compressors as necessary are installation devices, which is however disadvantageous for various reasons. First of all, installation devices are often used in places where the presence of the compressor poses some practical problems, for example in narrow streets or in small installation wells. Secondly, since it is often necessary to use several installation devices, for the installation of cables of considerable lengths, it appears the need to use the same number of compressors (or other sources of liquid under pressure), which substantially increases the cost of applying the method . Since each compressor usually needs an operator, the cost of labor can also be substantial in the case of installing cables over longer distances. Thirdly, moving a compressor to a new work location, for example when an additional compressor is required, is cumbersome, as compressors are generally heavy and difficult to relocate.

For example, the method described [1] may require four installation devices and, therefore, four compressors, to install a cable over a length of 2 km.

Other techniques included in the prior art, such as those described in documents [5] and [6], do not solve these problems.

Document [5] proposes relocating the compressor that injects air to another air inlet, belonging to the pipe as the cable installation progresses. Similarly, document [6] describes a method, in which the compressed air is introduced into a pipe through successive inlets. And here you need to move the compressor or use more compressors. In addition, these cited documents do not refer to the installation of cables with the use of two or more installation devices capable of exerting a mechanical force of pushing on the cable, for example by means of drive wheels.

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The invention aims to provide a method and a device for installing cables, which overcome the problems of the prior art, as well as others, and which ensure efficient installation of cables at low costs. The invention also aims to provide a method and device for installing cables, which will ensure efficient and versatile installation of cables even in places where a compressor or other source of pressure fluid (for example, a gas cylinder) cannot be used.

According to the invention, the method of installing a cable in a cable duct, by means of an installation device, operated with fluid, and comprising mechanical means for exerting a force of propulsion on the cable, said method comprising the steps of placing the device of a cable. installation at the end of the pipe, introducing a

EN 117486 Β1 of the fluid through the pipe starting from an inlet of the fluid distal to the installation device and inserting at least one cable through the pipe by means of the installation device, is characterized by actuating the installation device by the fluid which crosses the pipeline.

The invention is based on the fact that a means of propelling the cable, such as a pneumatic or hydraulic motor, can be operated remotely. The invention is further based on the fact that the pipes can be used not only to hold the cables, but also to transport fluid under pressure (such as gases and liquids). Of course, it is possible to use separate portable tubes or hoses that are installed along the compressors to operate them. Although this is a feasible solution, installing and then removing the separate drive tubes is an additional installation step, which increases costs. Therefore, it is less expensive and more practical to use tubes that are already in place when the cable installation actually begins.

The invention is also based on the observation that the problem of operating the remote installation devices, from different positions, exists and requires an efficient, less expensive solution. Due to the passage of the fluid through a pipe, in order to operate the installation devices, 65 it becomes possible to operate the installation devices remotely. It is also possible to operate several installation devices by a single distributed source of fluid.

The fluid inlet port for fluid supply to the pipe may be provided in another installation device. That is, another installation device can be used to insert the fluid into the pipe. According to another embodiment, the fluid inlet port 70 may be provided in the pipe. In the second case, an inlet of the fluid can be made in a section of the pipe.

The fluid and the cable may be passed through separate pipes or sections of pipes. Thus, a pipe parallel to the pipe or section of pipe in which the cable is installed can be used to transport the actuating fluid. This solution offers the advantage of 75 to allow a larger amount of fluid to be transported. However, the fluid and the cable may also be passed through the same pipe or section of pipe, for example, if only one pipe is present.

The installation devices are preferably located between sections of the pipeline and at the beginning of the pipeline. Depending on the length of the pipe sections, it is sometimes possible to insert the cable through two or more pipe sections using a single installation device.

The fluid used is preferably compressed air. However, other gases (such as nitrogen) or liquids (water, oil) can be used.

According to the method proposed in the invention, it is also possible to install at least two cables simultaneously, by simultaneously supplying an installation device with the group of cables or by arranging in parallel two installation devices. In the description, the term cable or cables will be used to refer to a group of cables, consisting of one or more copper cables, fiber optic cables, reinforced fiber bundles and the like. 90

In order to facilitate the advancement of the cable, when the direction of insertion of the cable coincides with the direction of transport of the fluid, the cable may be provided with a shuttle or drive plug. Such a shuttle, such as that described in [4], provides additional push force. Both semi-open shuttles (as in document [4] and closed shuttles can be used. 95

A device for installing cables comprising a receiving part for receiving a cable, a driving part provided with mechanical means for exerting a propulsive force on the cable and an insert part for introducing a cable.

RO 117486 Β1 cable in a pipe, said mechanical means being adapted for operation by means of a pressure fluid passed through the device, preferably comprises, according to the invention, means for actuating the mechanical means mentioned by means of a pressure fluid, provided to the device by a pipe section. Thus, the installation device according to the invention is adapted for operation by means of a fluid supplied through the pipe.

Following is an example of an embodiment of the invention, with reference also to FIG. 1 * 6, which represents:

FIG. 1 is a schematic illustration of a first method of applying the method according to the invention;

FIG. 2 is a schematic illustration of a second method of applying the method according to the invention;

FIG. 3 is a diagram of a first variant of an installation device according to the invention, having a separate drive part;

FIG. 4 is a diagram of a second variant of an installation device according to the invention, having an integrated drive part;

5 is a cross-section through a third embodiment of an installation device according to the invention, comprising a derivation for the passage of fluid from one pipe section to the next;

FIG. 6 is a cross-section through a fourth embodiment of an installation device according to the invention, particularly suitable for use with a shuttle.

The system, shown schematically and with an example role in FIG. 1, comprises installation devices 1a, 1b and 1c a cable 2, a cable drum 3, a compressor 4 and a pressure tube 5. The system is used to install cable 2 in a pipe consisting of pipe sections 6a, 6b and 6c.

As shown in Fig. 1, cable 2 is installed using the installation devices 1a, 1b and 1c, disposed at the beginning of the pipe sections 6a, 6b and 6c respectively. The first installation device 1a may be a device of the type described in the document [1]. The second installation device 1b and the third installation device 1c will be presented in more detail, with reference to Figs. 3 ... 6.

The cable 2 is detached from the cable drum 3 and inserted into the first installation device 1a. The direction of insertion of the cable (to the right in fig. 1) is indicated by a double arrow, while the direction of flow of the fluid (air) is indicated by a single arrow. The first installation device 1a is actuated by the fluid provided by the compressor 4 of the installation device 1a through the tube 5. The first installation device 1a is thus directly driven by the compressor 4 through the tube 5.

Preferably, the pressure fluid used is air, but other gases or even liquids, such as water, may be used. The compressor can be replaced by other suitable means, such as a pressurized container, a water pump and the like.

The first installation device 1a is placed at one end, that is at the end of the cable insertion, of the first pipe section 6a. Preferably, the installation device 1a will be located directly next to the pipe section 6a and will be connected to the pipe section 6a, tightly, to prevent fluid leakage. On the other hand, if the installation device is distanced from the pipe section, an adequate sealing must be provided, in order to close the pipe section, except for openings for cable insertion and fluid supply.

From the first installation device 1a, both the cable 2 and the pressure fluid are transported to the second and third installation devices 1b and respectively

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1c through the pipe sections 6a and 6b. For the purpose of a clearer illustration, the pipe sections 6a, 6b and 6c are shown in FIG. 1 considerably shortened.

As shown in Fig. 1, the flow direction of the fluid coincides with the direction of cable insertion. In this case, fluid flow can exert an auxiliary propelling force (fluid driving force 150) if the fluid speed is high relative to the cable speed. This will happen especially when the last pipe section (ie section 6c in Fig. 1) has a free outlet, ie when end 7 of pipe section 6c is open in the atmosphere. However, in some cases, it may be necessary to partially or totally close the outlet 7 of the pipe section 6c, in order to maintain sufficient pressure for installation devices 1b and 1c.

The system schematically illustrated in FIG. 2 also comprises installation devices 1a, 1b and 1c, a cable 2, a cable drum 3, a compressor 4 and a pressure tube 5. The system is used to install cable 2 in a pipeline also comprised of pipeline sections 6a, 6b and 6c. As in the system of Fig. 1, the cable 2 is 160 developed from the drum 3 and inserted into the first installation device 1a. Contrary to the system of FIG. 1, the pressure fluid is supplied by the compressor 4, through the tube 5 of the second installation device 1b, the fluid is transmitted through the pipe section 6a to the left, upstream from the cable, to the first device. installation 1a (located on the left end). The fluid is also transmitted, through the pipe section 6b) and to the 165 right side, between the cable downstream, to the third installation device (located at the right end). In the configuration shown in fig.2, the fluid flows through a pipe section (ie pipe section 6a) in the opposite direction of the cable insertion, and in another pipe section (ie the section represented by arrows in fig.2).

Since the fluid velocity will be kept low, the fluid driving force, which flows in the opposite direction to the cable insertion direction, is negligible. The fluid velocity in the pipe section 6a can be maintained at low values ​​by closing the outlet of the installation device 1a, at least partially.

As mentioned above, according to the invention, pipes or pipe sections 6a, 6b and 6c are used as means of transport for the actuating energy 175 of the installation device 1a, 1b and 1c. Preferably, said energy is contained in pressurized fluids, such as air, gases in general, water or other liquids, such as oil. As stated above, said compressor can be replaced, for example with a pressurized gas container or a hydraulic pump. Further to this description, the term air will be used to define specific examples, but this will not exclude the use of other fluids, both liquid and gaseous.

The method according to the invention may also be used in the case of a single installation device, which may be disposed at the upstream end of a pipe in relation to the direction of insertion of the cable, while the compressor may be disposed at the downstream end (which should be be properly closed to prevent fluid leakage, but 185 allowing cable passage). The fluid and cable travel in opposite directions if they flow through the same pipe. This configuration also ensures that the installation device is remotely operated via a pipe.

The installation device 1, shown as a block diagram and with an example role in FIG. 3, comprises a receiving part 10 for receiving a cable, for example from a section of 190 pipes, a driving part 11 for exercising a driving force. on a cable 2 and an insert part 12 for inserting the cable 2 into a pipe section. Said parts are connected to each other by means of tubes 15, 16, 17 and 18, preferably comprising valves 25, 26, 27 and 28. The tube 16 has a port of

RO 117486 Blow outlet 19, which can preferably be closed by valve 26. During use, the air passes from the receiving part 10, through the tubes 15, 16 and 17, to the insertion side.

12. If the air fluid is in the opposite direction of the cable insertion, the air goes in the opposite direction.

Drive part 11 comprises a pneumatic motor, which is moved (actuated) by means of the pressurized air passing through the pipe 18. The drive wheels 20, which are driven by the motor and which propel the cable 2, can be pressed to the cable. 2 by pneumatic means or by means of reports (not shown in fig. 3). The drive wheels 20 can be replaced with rails, if better contact with cable 2 is required. Since the drive part 11 is separated from the receiving part 10 and the insert part 12, the drive part must not be under pressure.

If the direction of insertion of the cable (indicated by the double arrow) coincides with the direction of air flow, the pressurized air can be sent to the next installation device through the (not shown) pipe section opposite the insertion part 12. In this case, the receiving part 10 it can receive pressurized air from the previous pipe section. It is also possible to reverse the flow of air under pressure. In this case, the insert part 12 receives air from a pipe section, and the receiving part 10 transmits the air to the next pipe section.

Valves 25, 26, 27 and 28 have the role of controlling the flow of air in the desired directions. These valves can be operated manually or automatically, preferably pneumatically. In the latter case, a pneumatic switch 21, operated by cable 2, which is installed, can be used for control purposes. Valves 22 and 23 (rendered as a rotary valve and a sliding valve respectively) serve to maintain air pressure when the tubes and the installation device are pressurized before inserting the cable. Valve 22 may also be provided as a passive valve, ie operated by cable 2, closing the receiving part 10, when the air is released into the atmosphere. In this case, the role of the switch 21 can be assumed by the valve 22.

In principle, the device 1 can be used without the mentioned valves and switches. In this case, the pipe connections are made manually, when necessary.

Parts 10, 11 and 12 can be divided longitudinally so that device 1 can be opened and arranged around cable 2. In this way, device 1 can be used to continue the installation of a cable that has already been partially installed.

Fig. 4 illustrates another embodiment of an installation device, according to the invention, largely identical to that shown in fig. 3. · The installation device 1, of fig. 4, represents the driving part 11 and the insertion 12 integrated in one part

13. This solution has the advantage that the cable is pulled rather than pushed into the pressurized insert part. On the other hand, a separate drive part normally leaves more space, for example for a track instead of the drive wheels 20. Also, a separate drive part does not need to be pressurized and thus allows a easy access to drive wheels 20 or equivalent means.

Fig.5 shows a cross-section through an installation device 1 according to the invention. This embodiment of the invention represents an adaptation of the device described in EP 0292037 and US 4850569. The device of FIG. 5 comprises a receiving part 10, a driving part 11 and an insertion part 12, connected together by a tube. integrated 16 (corresponding to the tubes 15,16 and 17 of fig. 3). The drive part 11 contains a pneumatic motor 30 intended for the propulsion of the cable 2 by means of the drive wheels 20.

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The drive part 11 also contains a pressure cylinder 31, intended for pressing the drive wheels 20 on the cable 2. The support wheels 29 do not have their own drive.

A tube 18 makes the pneumatic connection of the pneumatic motor 30 and of the pressure cylinder 31 with the receiving part 10, the motor 30 and the cylinder 31 are actuated.

The tube 16, which makes the pneumatic connection between the receiving part 10 and the insertion part 12, allows the air to pass through these parts to a subsequent pipe section. Thus, in the device 1 of FIG. 5, the air bypasses the driving part 11 through the tube 16 and reaches the next section of pipe (not shown) through the tube 37 or the tube 38, depending on the direction of transport of the fluid. Both the tube 16 and the tube 18 can optionally be provided with suitable valves for regulating the flow of air.

In a field test, the device of FIG. 5 was used to install a cable with a diameter of 13 mm in a pipe with a length of 100 m and an inside diameter of 27 mm. At the beginning of the pipe, a device of the type described in the document [1] was used, while the device shown in FIG. 5 was placed 650 m from the beginning of the pipe. The cable was successfully installed, although the pressure at the beginning of the pipe was only 4.5 bar, in this test no shuttle was used.

Fig. 6 shows a cross-section through another embodiment of the installation device 1 according to the invention, particularly suitable for the installation of cables by means of a so-called shutters (drive plug), in which the air does not bypass the part drive 11, but is inserted directly through the device.

The installation device of Fig. 6 is largely similar to the device 1 of Fig. 5, so that, partially similar, they were noted with the same reference signs. The device of FIG. 6, however, does not have a separate receiving part. The drive receiving part 11 and the insert part 12 are integrated into a housing 35.

The housing 35 can be divided longitudinally into two sections to allow the device 1 to be disposed around a cable. As in the case illustrated in FIG. 5, the receiving and insertion tubes 37 and 38, respectively, are secured by means of clips 36 so as to immobilize the tubes 37 and 38 relative to the housing 35, when under pressure. The tubes 37 and 38, respectively receiving and inserting, not only serve to receive and insert a cable, but also to transport the fluid in device 1 from an adjacent (not shown) pipe section and from device 1 to the next adjacent pipe section.

Centrally located in the housing 35, there is a cylindrical channel, consisting of a guide tube (partially perforated) 40, through which both the cable 2 and the air under pressure can pass. The guide tube 40 is provided with opposing openings 41, which allow the drive wheels 20 and the support wheels 29 to reach the cable 2. In the drive part 11, the guide tube 40 is also provided with the perforations 42, and in the insertion part 12, the guide tube 40 is provided with the perforations 43 and 44. These perforations 42, 43 and 44 serve to pass air through the tube. guide 40 to the driving part 11 and to the insertion part 12 respectively, as will be explained below.

The cable 2 shown in Fig. 6 is provided with a shuttle 50 which has flaps 51. Such a shuttle effectively closes the guide tube 40, although a half-open shuttle can be used, which causes a lower pressure gradient. During operation, the shuttle 50 passes through the openings 41 of the guide tube 40 in front of the cable (the direction of insertion of the cable is again indicated by the double arrow). As this process occurs, drive part 11 will quickly fill with pressurized air. In order to prevent the deformation of the flaps 51 of the shuttle 50, due to the prediction gradient, the guide tube 40 is preferably provided with the perforations 42 located to the left of said openings 41.

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Once the shuttle 50 has passed through the perforations 43 of the guide tube 40, more and more air will gradually flow into the insertion part 12. This air will initially flow out through the perforations 44 and leave the installation device 1 through the tube 38 The maximum pressure will be formed in the enclosure 12 only when the shuttle 50 reaches the last perforations 44. This pressure can be used to move the pneumatic motor 30 and the pressure cylinder 31 through the tube 17, the valve 28 and the tube 18. For this, the holes 43 and 44 in the guide tube 40 should be large enough to allow sufficient air flow to the motor 30 and cylinder 31. On the other hand, the perforations 43 and 44 should be sufficiently large. small to maintain the pressure required to propel the shuttle. Through these perforations, a gradual actuation of the installation device can be achieved.

Instead of the aforementioned perforations, a single slot or orifice (not shown) may be provided to allow the passage of air to the enclosure of the insert part 12. In practice, the shuttle may be longer than the section of the guide tube 40, which is provided with the perforations 43. and 44. In this case, the air is not allowed to leak near the shuttle, ie from inside the guide tube 40 through the holes 43 and 44 to the tube 38. A longer shuttle can be used to reduce or even effectively prevent this leak. In order for a longer shuttle to be able to surpass the possible bends of the pipe, it can be made of two parts joined by a flexible rod or cord, or it can have an elongated, flexible body.

The valve 28 can be used to stop the engine 30. The cylinder 31 presses the drive wheels 20, which are preferably provided with grooves to increase the friction force, to the cable 2. The support wheels 29, disposed on the opposite side, may be passive, that is, without their own actuation, and may remain in a fixed position, that is, without being fitted with a pressing cylinder. The pressure relief valve 26 can be used to release the excess pressure.

In the device shown in FIG. 5, the air required to start the motor 30 is taken from the receiving part 10, while in the device shown in FIG. 6, the motor 30 is moved by the air taken from the receiving part 10. insertion 12.

In summary, the invention proposes a method for installing cables in pipes (preferably previously installed), using installation devices that propel the cables inside the pipes. The propelling force is preferably exerted by drive wheels or other similar elements, but may also be represented by the fluid driving force. The installation devices are operated by means of a pressure fluid, such as air transported through pipes. For the transport of the fluid under pressure, the pipe in which the cable and / or one or more parallel pipes can be used can be used. The direction of insertion of the cable may coincide with the direction of transport of the fluid or it may be opposite.

It should be understood by those skilled in the art that the embodiments of the invention, described above, have been presented by way of example only, so that they can be made numerous additions and modifications without departing from the concept of the invention. For example, the method and devices described above can also be used to remove cables from pipes.

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