DE9018133U1 - Device for pulling at least one cable or an auxiliary cable into a cable protection tube by means of a medium flowing under pressure - Google Patents

Description

ABB Patents GmbH

Mannheim 20 September 1995

PAT 7-Mi/Ca

Description

Device for pulling at least one cable or an auxiliary rope into a cable protection pipe by means of a medium flowing under pressure

The invention relates to a device for pulling at least one cable or an auxiliary rope into a cable protection pipe by means of a medium flowing under pressure, whereby an inlet housing seals the cable protection pipe in a pressure-tight manner and is provided with a cable guide bushing for the sealing introduction of the cable or auxiliary rope to be laid and whereby the cable or auxiliary rope to be laid is connected to a pulling piston which slides sealingly within the cable protection pipe.

Such a device is known from DE 32 20 286 Al. There it is proposed to divide the laying section into several laying sections, whereby the cable is continuously pulled through several such sections. In addition to the pull plug attached to the beginning of the cable

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(tension plugs), at least one additional tension plug is installed as an intermediate plug in at least one further installation section and is also pressurized with compressed air.

In practice, it is often necessary to lay new cables in existing cable duct systems (cable protection pipe systems). The existing cables should not be pulled out, nor should the existing lines be switched off.

The invention is based on the object of specifying a device for pulling at least one cable or an auxiliary rope into a cable protection pipe by means of a medium flowing under pressure, which can also be used with cable protection pipes already equipped with at least one cable. Furthermore, a method for this is to be specified.

This object is achieved according to the invention with regard to the device in conjunction with the features of the preamble by the features specified in the characterizing part of claim 1.

The advantages that can be achieved with the invention are in particular that for the subsequent laying of cables or auxiliary ropes, the cables already present in the cable protection pipe do not have to be pulled out of the cable protection pipe. Rather, these existing cables can remain in the cable protection pipe and continue to be used even during the pulling-in process.

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The process and the device do not require any heavy physical work, are material-saving, require relatively little working time and are not very cost-intensive. Any length of cable or auxiliary rope can be pulled in, since for relatively long cable lengths, additional intermediate pits are provided along the entire route.

The seals on the pull piston and on the cable guide bushing of the entry housing are flexible and adapted to the cable protection tube and the cable in the cable protection tube in such a way that they hermetically seal the interior of the cable protection tube without, however, generating a large frictional resistance.

The invention is explained below using the embodiments shown in the drawing. Show:

Fig. 1, 2 Principle representations of pulling a cable into a cable protection pipe,

Fig. 3 an introduction housing in detail as a longitudinal section,

Fig. 4 a pair of pliers for the insertion housing, Fig. 5 the basic structure of the insertion housing in cross section,

Fig. 6 a pulling piston located inside the cable protection tube,
Fig. 7 a pull piston in detail.

Figures 1 and 2 show schematic diagrams of the pulling of a cable into a cable protection pipe. The task is to subsequently pull a cable 5 - preferably a fiber optic cable - into a cable protection pipe 1 laid in the ground, and the cable 5 should be pulled in from the

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Socket pit 19a (cable shaft) to socket pit 19b (cable shaft). For this purpose, the total distance between the two socket pits 19a, 19b is divided into two sections 20a, 20b, with the first section 20a running from an intermediate pit 18 to be dug to socket pit 19a and the second section 20b running from intermediate pit 18 to socket pit 19b.

The cable protection pipe 1 is cut open at the location of the intermediate pit 18 so that the sealing inlet housing 3 described in more detail in Figure 3 can be placed on the section of the cable protection pipe 1 leading to the socket pit 19a and firmly connected to it. Since at least one cable 2 that has already been laid is arranged in the cable protection pipe 1 itself, the inlet housing 3 is provided with a removable side strip (see number 22 in Figures 3 and 5) that allows the cable 2 that has already been laid to be inserted into the inlet housing without cutting open the cable. A two-part cable guide bushing 4 at the outlet of the inlet housing 3 serves to fix the cable 2 that has already been laid to the inlet housing and to guide the new cable 5 that is to be laid in a sealed manner.

The new cable 5 to be laid is unwound from a cable drum 6, whereby the unwinding speed of the cable drum 6 can be regulated by means of a brake drum stand. This, as well as the inlet valve on the blowing fitting 7, allows a uniform desired pulling-in speed (preferably 30 to 60 meters) of the cable 2 within the cable protection pipe 1 to be set. Between the cable drum 6 and the intermediate pit 18 there is a cable guide 8 with a dirt scraper as well as a traction recorder with a meter counter and tachometer for recording the tension during the pulling-in process.

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the tensile forces acting on the cable 5, the length of the cable being pulled in and the pulling-in speed. A cable oiler 10 is arranged directly in front of the pulling-in housing 3, which ensures low-friction pulling of the cable 5 through the sealing cable guide bushing 4 by releasing lubricant.

To pull in the cable 5, the inlet housing 3 is provided with a compressed air connection 11, to whose coupling 25 a compressed air hose 12 leading to a compressor 13 is connected. The compressor 13 generates compressed air with a maximum pressure of approximately 16 bar and a maximum delivery rate of approximately 10 m3/min. The pressure effective within the cable protection pipe 1 can be adjusted using an injection fitting 7 with inlet and outlet valve and pressure gauge. In particular, the injection pressure must be continuously increased as the length of the cable 5 being pulled in increases in order to compensate for the increasing frictional forces between the cable 5 and the inner jacket of the cable protection pipe 1 and to keep the pulling-in speed constant. Number 15 designates a welded or screwed sleeve which is used to close the separated cable protection pipe 1 after the cable pulling-in process has been completed.

The cable 5 itself is pulled in using a pulling piston 16 (injection piston) connected to the cable 5 and described in more detail in Figures 6 and 7. This pulling piston 16 slides sealingly inside the cable protection pipe 1 and is driven by the upper pressure produced in the cable protection pipe 1 by the compressor 13 from the intermediate pit 18 to the socket pit 19a. For safety reasons, a piston catcher 17a is located at the outlet of the cable protection pipe 1 into the socket pit 19a. This piston catcher 17a prevents an uncontrolled exit of the pulling piston 16 in the event of an

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cuell Break in the connection between pull piston 15 and cable 5.

When the cable 5 has been laid along the section 20a from the intermediate pit 18 to the socket pit 19a, the remaining cable section is unwound from the cable drum 6 and laid down to form a loop 9, as shown in Figure 2. The now free cable end of the cable 5 is ready for further laying in the section 20b. To do this, the pulling piston 16 is mounted on the cable 2 in the cable protection pipe 1 and connected to the free cable end of the cable 5 (see Figure 6). The pulling piston 16 is then pushed with the cable 5 into the cable protection pipe 1 leading to the socket pit 19b. This cable protection pipe is now closed with the introduction housing 3 previously removed from the cable protection pipe leading to the socket pit 19a. The subsequent retraction of the pulling piston 16 connected to the cable 5 takes place in the same way as described above for Figure 1, whereby a piston catcher 17b is located at the outlet of the cable protection tube 1 into the socket pit 19b.

After the cable has been laid along the second section 20b in the cable protection pipe 1, the entry housing 3 can be removed from the severed cable protection pipe 1. After the two severed sections of the cable protection pipe 1 have been connected using the welded or screwed sleeve 15, the intermediate pit 18 can be filled.

If the cable 5 is to be laid within a relatively short cable protection pipe 1, it can of course be pulled in directly from one socket pit 19a to the other socket pit 19b, without an additional intermediate pit 18 being necessary between the two socket pits 19a, 19b.

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In Figure 3, an inlet housing is shown in detail as a longitudinal section. The inlet housing 3 has an elongated, one-piece base body 21 with a central channel 32 in the longitudinal direction and a continuous side opening for the introduction of the already laid cable 2. This side opening can be closed using the already mentioned removable side strip 22. A handle 23 facilitates the assembly/disassembly of the strip 22. To hold the strip 22 and the two-part cable guide bushing 4 in the assembled state, the base body 21, strip 22 and cable guide bushing 4 are provided with holes 26 through which retaining bolts 27 are inserted after the strip has been assembled.

A temperature measuring device attached to the base body 21 and connected to the channel 32 can be provided for recording the current air temperature inside the entry housing 3 and thus inside the cable protection tube 1. If the temperature exceeds a predetermined limit value (eg 60 ⁰ C), suitable measures must be taken (eg cooling the cable protection tube or interrupting the pulling-in process) to prevent the cable 5 under tension from being exposed to inadmissible temperature influences.

The compressed air connection 11 mentioned above is arranged on the side of the base body 21 and is directly connected to the channel 32. The compressed air connection 11 has a coupling 25 for connecting the compressed air hose 12.

The above-mentioned separate cable guide bushing 4, arranged at the outlet of the inlet housing 3, is constructed in two parts from two symmetrical halves and

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z at least one hole 28 for receiving and fixing a cable that has already been laid and at least one hole 29 for receiving and guiding the new cable to be laid. The division of the cable guide bushing 4 runs centrally through these holes. At least the hole 29, but preferably also the hole 28, have annular recesses for receiving sealing rings 31 and 30, which ensure that the pressurized channel 32 of the entry housing 3 is sealed against the outside atmosphere. The sealing rings 30, 31 are slotted so that they can be placed over the cables 2, 5. Furthermore, the sealing rings 30, 31 are flexible in order to be able to compensate for deviations in the cable outer diameter from the nominal value. If several cables are already laid inside the cable protection pipe 1 and if several cables are to be subsequently pulled into the cable protection pipe 1, additional holes must be provided in the cable guide bushing 4, as already indicated above.

For the sealing connection of the inlet housing 3 with the cable protection tube 1, a collar 33 is provided on the base body 21 or on the strip 22, the outer diameter of which is adapted to the inner diameter of the cable protection tube 1, so that the cable protection tube can be pushed onto this collar. A pair of pliers 34 is used to hold the pushed-on cable protection tube 1, the two jaws 35 of which enclose the cable protection tube 1, as shown in Figure 4. The jaws 35 are attached to lever arms 37 connected to one another via a joint 36. These lever arms 37 are pressed against one another by a screw connection 38 with an adjustable, predeterminable pressure. In addition, a positive connection of the jaws 35 themselves with the inlet housing 3 is made by pins 39 attached to the jaws 35, which are in corresponding

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corresponding holes 40 of the entry housing 3. This additional connection creates a better clamping of the entry housing with the cable protection tube.

Figure 5 shows the basic structure of the introduction housing in cross section with base body 21, side bar 22 with handle 23, holes 26 in the base body and in the side bar, retaining bolt 27 and central channel 32.

Figure 6 shows a pull piston located inside the cable protection tube, while Figure 7 shows a pull piston in detail.

The pull piston 16 has a one-piece, elongated piston body 41 with a central channel 42 in the longitudinal direction. At both ends of the piston body 41 there are projections 43a, 43b that are circular in cross section, with a half-shell 44 additionally arranged on the projection 43a. The piston body 41 is open on one side and the projections 43a, 43b have corresponding lateral recesses so that the central channel 42 is open over its entire length and the cable 2 that has already been laid can be easily inserted.

Both projections 43a, 43b are each provided with three threaded bolts 45a, 45b, the central axes of which run parallel to the central channel 42. The threaded bolts 45a, 45b are arranged at equal intervals along the circumference of the projections 43a, 43b. Preferably, two threaded bolts 45a are located directly on the projection 43a, while one threaded bolt 45a runs through the half-shell 44.

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After the already laid cable 2 has been guided into the central channel 42, a separate half-shell 46 is inserted into the projection 43a in such a way that a hollow cylinder is formed that encloses the cable 2 and consists of the half-shells 44 and 46. The half-shell 46 is provided with corresponding holes for the threaded bolts 45a to pass through.

An elastic seal 48a can then be pushed onto the hollow cylinder formed by the half-shells 44, 46 in such a way that an inner ring-shaped sealing lip 49a of this seal engages in the hollow cylinder itself, while an outer sealing lip 50a of this seal envelops the outer casing of the hollow cylinder. The inner sealing lip 49a seals against the cable 2 and the outer sealing lip 50a ensures the seal against the cable protection pipe 1. While the inner diameter of the inner sealing lip 49a corresponds relatively exactly to the outer diameter of the cable 2, the outer diameter of the outer sealing lip 50a is slightly larger than the nominal inner diameter of the cable protection pipe 1. This ensures that even if the inner diameter of the cable protection tube 1 deviates from the nominal inner diameter, there is sufficient sealing between the seal 48a and the cable protection tube 1, since the outer sealing lip 50a compensates for such deviations. In addition, the outer sealing lip 50a does not lie directly on the outer casing of the hollow cylinder, but is located at a certain distance A from the outer casing, so that the sealing lip 50a can adapt to the changing inner diameter of the cable protection tube 1 within certain limits. This is important if, for example, the cable protection tube 1 has an oval rather than a circular cross-section in sections.

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Even with such a deformation of the cable protection pipe 1, a secure seal between seal 48a and cable protection pipe 1 is still guaranteed.

The seal 48a is preferably made of leather and has holes on its end faces 52a connecting the sealing lips 49a, 50a, whereby these holes are placed and dimensioned according to the position and dimensions of the threaded bolts 45. Furthermore, the seal 48a is provided with a slot 47 in order to be able to easily attach it to the cable 2 (see slot 47 of the seal 48b).

After the seal 48a has been pushed on, a plastic disk 53a with corresponding holes is placed on the threaded bolts 45a. This plastic disk 53a is preferably made of Teflon and is provided with a slot so that it can be placed on the cable (see slot 51 of the plastic disk 53b).

A support disk 55 - preferably made of metal - with corresponding holes can then be placed on the threaded bolts 45a. The support disk 55 has a recess so that it can be easily placed on the cable 2. Nuts 58a are then screwed onto the threaded bolts 45a and tightened with a predefined torque. As a result, the front surface 52a of the seal 48a is pressed against the front surface of the hollow cylinder via the support disk 55 and the plastic disk 53a, which is advantageous for the secure fixation of the seal 48a.

First, a plastic disk 53b, then a seal 48b and finally a separate half-shell 59 and a slotted bushing 60 with half-shell are placed on the threaded bolts 45b of the further projection 43b.

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le, whereupon nuts 58b are tightened, wherein all components are provided with corresponding holes adapted to the position of the threaded bolts 45b. The bushing 60 has two side slots 61 for passing through and fixing a traction and buffer cable 62. Half-shells 59 and bushing 60 form - in the same way as described above for half-shells 44, 46 - a hollow cylinder for sliding on the seal 48b with inner sealing lip 49b and outer sealing lip 50b.

The front surface 52b of the seal 48b is supported against the projection 43b via the plastic disk 53b.

The traction and buffer cable 62 is preferably connected to the cable pulling eye 65 of the cable 5 to be laid via a quick-release chain fastener 63 and a swivel 64. The cable pulling eye 65 is preferably designed in accordance with DE-Gbm 90 11 044.7. Since the traction and buffer cable 62 is attached symmetrically to the slotted bushing 60, tilting of the traction piston 16 during the pulling-in process as a result of asymmetrical tensile loading is prevented:

Since the piston body 41 of the pulling piston 16 is completely open on one side, the center of gravity is shifted outside the central axis. This eccentric center of gravity advantageously prevents the pulling piston from twisting inside the cable protection tube 1 during the pulling-in process.

If several cables are already laid inside the cable protection tube 1, additional inner sealing lips 49a, 49b must be provided for the seals 48a, 48b. Furthermore, the central channel 42 of the piston body 41 and the projections 43a, 43b as well as the

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supporting components, such as half shells 44, 46, 59 and bushing 60 and the fixing components, such as plastic disks 53, 53b and support disk 55, must be adjusted accordingly.

In the exemplary embodiment, compressed air is provided as a medium flowing under pressure. However, water can also be used as a medium. In the exemplary embodiment, the laying of a cable, in particular a fiber optic cable, is described. However, it is equally possible to pull in an auxiliary rope instead of a cable. This auxiliary rope can then be used to pull one or more cables, pipes, lines or other components into the cable protection pipe.

Claims (18)

Mp.-NR. 90/639 1 .5·. \.' *2tf. .tfeptembet? 1995 Protection claims 1. Device for pulling at least one cable or an auxiliary cable into a cable protection pipe by means of a medium flowing under pressure, wherein a guide housing (3) seals the cable protection pipe (1) in a pressure-tight manner and is provided with a cable guide bushing (4) for the sealing introduction of the cable (5) or auxiliary cable to be laid, and wherein the cable (5) or auxiliary cable to be laid is connected to a pulling piston (16) which slides sealingly within the cable protection pipe, characterized in that the introduction housing (3), the cable guide bushing {4} and the pulling piston (16) can be opened in such a way that at least one cable (2) already laid within the cable protection pipe (1) can be received without being separated, that the cable guide bushing (4) has, in addition to the bore (29) for the new cable (5) or auxiliary cable to be laid, at least one further, openable, sealing bore (28) for the at least one cable (2) already laid and that the pulling piston (16) is additionally provided with at least one seal (49a, 49b) which slides sealingly along the cable (2) already laid. 2. Device according to claim 1, characterized in that the introduction housing (3) consists of a base body (21) with a central channel (32) and a removable side strip (22). Mp.-No. 90/639 2 -'V*/ :"3$ ^V :SepE«Elr 1995 3. Device according to claim 2, characterized in that the base body (21), the side strip (22) and the cable guide bushing (4) are provided with bores (26) through which retaining bolts (27) engage to lock the mounted strip (22) and cable guide bushing (4). 4. Device according to at least one of the claims 1 to 3, characterized in that the bore (29) in the cable guide bushing (4) for the new cable (5) or auxiliary cable to be laid is provided with a flexible, preferably slotted sealing ring (31). 5. Device according to at least one of the claims 1 to 4, characterized in that the bore (28) in the cable guide bushing (4) for the already laid cable is provided with a slotted, flexible sealing ring (30). 6. Device according to at least one of claims 1 to 5, characterized in that the cable guide bushing (4) consists of two symmetrical halves, the separation plane running through both bores (28, 29). 7. Device according to at least one of claims 1 to 6, characterized in that the introduction housing (3) has a collar (33) whose outer diameter corresponds to the inner diameter of the cable protection tube (1) and which is suitable for insertion into the cable protection tube (1). 8. Device according to claim 7, characterized in that, for fastening the cable protection pipe (1) pushed onto the collar (33), the jaws (35) of a pair of pliers (34) are clamped around the pushed-on cable protection pipe Mp. No. 90/639 '<' * ' ^: '^ ·' ^{MDi:aiBUB1 1995} (1), the jaws (35) being connected to lever arms (37) which are connected to one another via a joint (36) and can be pressed against one another via a screw connection (38). 9. Device according to claim 8, characterized in that the jaws (35) are additionally connected to the base body (21) of the insertion housing (3) via fastening means (39, 40). 10. Device according to at least one of claims 1 to 9, characterized in that the pulling piston (16) has a piston body (41) open on one side with a freely accessible central channel (43). 11. Device according to claim 10, characterized in that at least one hollow cylinder is formed at least at one end of the piston body (41) by means of two half-shells (44, 46, 59, 60) that can be joined together, over the outer casing of which a flexible, slotted seal (48a, 48b) engages with its outer sealing lip (50a, 50-b) and into which the same seal engages with its inner sealing lip (49a, 49b), the inner diameter of the inner sealing lip being adapted to the outer diameter of the cable (2) already laid and the outer diameter of the outer sealing lip being adapted to the inner diameter of the cable protection pipe (1). 12. Device according to claim 11, characterized in that the seal (48a, 48b) consists of leather. 13. Device according to claim 11 and/or 12, characterized in that the outer diameter of the outer sealing lip (50a, 50b) is slightly larger than the nominal inner diameter of the cable protection pipe (1) and there is a predetermined distance (A) between the outer sealing lip (50a, 50b) and the outer casing of the hollow cylinder. Mp.-No. 90/639 4 .".···: ,··#)·.·, September 1995 14. Device according to at least one of claims 11 to 13, characterized in that the end face (52a, 52b) of the seal (48a, 48b) connecting the inner (49a, 49b) with the outer sealing lip (50a, 50b) is pressed against the end face of the hollow cylinder. 15. Device according to claim 14, characterized in that the pressing takes place via a slotted plastic disk (53a, 53b) and optionally via an additional metallic protective disk (55) with a recess adapted to the outer diameter of the laid cable. 16. Device according to claim 15, characterized in that the piston body (41) is provided with several threaded bolts (45a, 45b), through which both the half shells (44, 46, 59, 60) and the seal (48a, 48b), the plastic disk (53a, 53b) and optionally the support disk (55) can be plugged on via corresponding holes and pressed against one another by means of nuts (58a, 58b). 17. Device according to at least one of claims 10 to 16, characterized in that a bushing (60) with side slots (61) for fixing a traction and buffer cable (62) connected to the cable (5) or auxiliary cable to be newly laid is attached to the piston body (41). 18. Device according to claim 17, characterized in that the traction and buffer cable (62) is connected to the cable (5) or auxiliary cable to be laid via a chain quick release (63) and a swivel (64).