WO2004049533A1 - Installation element for a telecommunication element, method for the production of such an installation element, and method for installing a telecommunication element - Google Patents

Abstract

The invention relates to an installation element for a telecommunication element comprising an elongate metallic pipe (1) for guiding the telecommunication element (5). In order to produce said installation element, an inner wall (4) of the guiding pipe, which faces the interior (9) thereof, is provided with plastic (8) such that the inner wall of the guiding pipe is smoothly sealed with plastic. According to the inventive installation method, a telecommunication element (5) is later inserted into the interior of such a guiding pipe by means of a longitudinal movement, whereby an installation element is created which has good rigidity and a low friction coefficient relative to a telecommunication element that is to be inserted.

Description

description

Installation element for one. Message transmission element, method for producing such a laying element and method for laying a message transmission element

The present invention relates to a laying element for a message transmission element with an elongated metallic guide tube for guiding the message transmission element and a method for producing such a laying element. The invention further relates to a method for laying a message transmission element within an elongated metallic guide tube.

For certain applications, it is common to incorporate a message transmission element, for example in the form of an optical cable, or corresponding cable arrangements for laying in a channel or in a fixed laying ground. When laying, there is generally a choice between several variants. In a first variant, the message transmission element is introduced directly into the channel or into the laying reason during the laying process. In a second variant, an empty pipe or guide pipe is first laid in the relevant channel or installation reason. The message transmission element is then inserted into the guide tube in question. Here, the transmission element is subsequently installed in the interior of the guide tube by longitudinal movement, for example by blowing in, flushing in or drawing in, in the longitudinal direction.

Plastic tubes made of polyethylene (PE tubes) are currently usually used as empty tubes or guide tubes. However, these have the disadvantage that they do not have too high a lateral pressure stability and tend to kink. This could occur during installation and later use Earthworks are easily damaged or compressed to such an extent that a cable can no longer be inserted. Furthermore, due to their limited temperature resistance, PE pipes are only suitable to a limited extent for installation processes in which the PE pipes are exposed to a higher temperature (e.g. 170 - 200 ° C). In contrast, metallic guide tubes have the advantage of increased stability in the transverse direction of the guide tube, but have a comparatively high coefficient of friction compared to a message transmission element to be introduced in the longitudinal direction, so that a comparatively high frictional force must be overcome during the subsequent installation of the transmission element.

The present invention has for its object to provide a laying element that has good strength and a comparatively low coefficient of friction compared to a message transmission element to be introduced.

Furthermore, it is an object of the present invention to provide a corresponding method for producing such a laying element and a corresponding method for laying a message transmission element.

This object is achieved by a laying element according to claim 1, by a method for producing a laying element according to claim 7 and by a method for laying a message transmission element according to claim 18.

According to the invention, a laying element for a message transmission element is provided with an elongated metallic guide tube for guiding the message transmission element, an inner wall of the guide tube facing the interior of the guide tube being coated with plastic, which seals the inner wall smoothly. The plastic coating on the inside wall of the me- metallic guide tube, the coefficient of friction of the laying element with respect to a subsequent transmission element to be introduced is significantly reduced. At the same time, the laying element according to the invention has high transverse pressure stability and strength due to the use of a metallic guide tube. The invention has the further advantage that additional corrosion protection is provided on the inside of the metallic guide tube and the condensation of the moisture is reduced by the plastic. Bumps such as joints or welds are covered by the plastic coating, so that the friction at these points is additionally reduced.

An abrasion-resistant plastic material, such as a thermoset, thermoplastic or a resin mixture, is preferably used to produce the plastic coating.

To further reduce the coefficient of friction, the plastic advantageously has cavities which are filled with a friction-reducing substance, in particular with oil, wax or fat. When the message transmission element is pulled in, these lubricants are preferably released by friction and temperature and additionally prevent the friction between the pipe wall and the message transmission element.

The invention describes several ways of applying the plastic coating to the inner wall of the guide tube.

In a first embodiment, a plastic-coated metal band with a surface that is smoothly sealed with plastic is formed into an elongated tube for shaping the guide tube, the smoothly sealed surface facing the interior of the guide tube after the shaping. For example, one is placed on a surface beforehand plastic-coated sheet welded into a tube. However, it is disadvantageous that the seam at which the tape ends are welded together is without a plastic coating.

In a further embodiment of the invention, the inner wall of the guide tube is coated with plastic after it has been formed, so that the inner wall of the guide tube is sealed smoothly with the plastic. According to this embodiment, the inner wall of the guide tube is subsequently lined with the plastic.

In an embodiment which is advantageous in this regard, the plastic is applied by powder coating the inner wall of the shaped guide tube, in particular using a vortex sintering method. Due to the process, an orange peel effect is achieved by the powder coating process, so that the static friction is reduced and the good sliding of the message transmission element is supported when it is subsequently introduced into the guide tube. When using a sintering process, the cavities mentioned above are created, which can be filled with oil, wax or fat. By using a sintering process, the plastic coating adheres firmly to the pipe wall. Furthermore, the plastic layer is self-contained and thus contributes to a further stabilization of the plastic coating on the metal pipe.

In a further embodiment of a production method according to the invention, the plastic is applied by introducing a plastic emulsion into the shaped guide tube. In particular, for this purpose the guide tube is stored on a storage drum, the storage drum being rotated during or after the plastic emulsion has been introduced. Here, the emulsion is conveyed through the entire reeled-up guide tube. This manufacturing process is mainly used when the metallic guide tube is through a drawing process was produced and is therefore available in comparatively long pipe lengths. In this case, it is currently not technically possible, as in the case of a method in which a metal strip is formed into a metal tube and longitudinally welded, to apply the plastic by a vortex sintering method.

In a further embodiment, the plastic is applied as a self-contained ring structure and is self-supporting as a "tube in tube".

Further advantageous developments and developments of the invention are specified in the subclaims.

The invention is explained in more detail below with reference to the figures shown in the drawing, which illustrate exemplary embodiments of the present invention. Show it:

FIG. 1 shows a cross section of a laying element with a metallic guide tube according to the invention,

FIG. 2 shows a schematic representation of a production line for producing a laying element according to the invention in a longitudinal section,

FIG. 3 shows schematic representations of a device for producing a laying element according to the invention,

FIG. 4 shows a schematic illustration of a further device for producing a laying element according to the invention,

Figure 5 is a schematic representation of a production line for forming a laying element according to the invention.

FIG. 1 schematically shows a cross section of a laying element with an elongated metallic guide tube. measure of the invention shown. The metallic part of the guide tube 1 is advantageously formed from copper, aluminum or sheet steel, copper being comparatively ductile and nevertheless stable in transverse pressure. A message transmission element 5 is arranged in the interior 9 of the guide tube 1, for example in the form of an optical cable or an optical fiber. The inner wall 4 of the guide tube 1 facing the interior 9 is provided with a plastic coating 8 which seals the inner wall 4 smoothly.

The guide tube 1 according to FIG. 1 is formed from a metal band, the band ends being connected to one another at a longitudinal weld 6. For example, the guide tube 1 is bent from a longitudinally running copper sheet and its sides are then continuously welded to one another. 1 shows that the longitudinal seam 6 at the joint 7 was intentionally not completely welded through. The remaining small gap to the inside of the pipe secures a rootless weld in the inside of the pipe, so that roughness due to the formation of a weld root is avoided. By sealing the inner wall 4 by means of the plastic coating 8, the coefficient of friction of the laying element with respect to the message transmission element 5 to be introduced is reduced. The message transmission element 5 can thus be subsequently introduced into the interior 9 of the guide tube 1 with comparatively low friction by longitudinal movement.

FIG. 2 shows a schematic representation of a production line 11 for producing a laying element according to the invention in a longitudinal section. The guide tube 1 is formed from a metal strip, the strip edges being longitudinally welded to one another. The elongated guide tube is produced by means of several bending stages connected in series, the strip edges then being welded to one another. The welding is carried out by a welding device 14. Layering 8 of the inner wall 4 of the guide tube 1 is applied by powder coating, in particular by a vortex sintering process. The emerging plastic granulate 13 is applied by means of a hollow needle 17 arranged in the interior 9, which has an opening 15 in the direction of withdrawal 23 of the guide tube after the welding point in the form of a mouthpiece for the exit of the plastic granulate. A plastic covering 10 is initially formed by the emerging plastic granulate 13 and solidifies into the plastic coating 8.

The application of the plastic granulate 13, which emerges at the mouthpiece 15, is advantageously supported by an electrostatic field 20, which is caused by charging the plastic granulate 13 and the inner wall 4 with opposite polarity. As a result, provisional adhesion and even distribution of the plastic powder on the inner wall is achieved. In the present exemplary embodiment, the plastic granulate 13, which is deposited on the inside of the tube, is negatively charged by means of the electrical connection 18, and the metal tube 1 is contacted with ground by the grounding device 12. The electrically charged plastic granulate is initially collected in the container 19. A subsequent heating process by means of the heating stages 22 allows the separated plastic granulate to be sintered with the inner wall of the tube in accordance with the principle of vortex sintering. Here, the metal tube is heated from the outside to about 200 ° C.

FIG. 3 shows schematic representations of a device for producing a laying element according to the invention that is different from FIG. The device shown can be used particularly advantageously when the guide tube is produced by a drawing process and not by a welding process as described above. Usual pipe lengths are 1 to 2 km, the pipe being wound on a storage drum. In Figure 3 Such a device 26 is shown, in which the guide tube 1 is drummed on a storage drum, not shown. A pipe start 27 and a pipe end 28 are accessible from the outside. A plastic emulsion 33 is filled in via a metering container 31 at the start of the tube 27, so that an initial level 32 is formed. An external wetting of the plastic can begin to wet the tube wall. In the lower part of FIG. 3 it is shown how the emulsion 33 is conveyed through the turns 29 of the tube 1 by rotating the drum and how the inner tube wall is completely wetted. The excess emulsion 34 is flushed out at the pipe end 28 (reference number 35). The drum is rotated in the direction of rotation 36. The external heat supply is carried out in the lower part of the figure in FIG. 3 by a heater 41.

FIG. 4 shows a schematic illustration of a further device in the form of a heating furnace 37 for producing a laying element according to the invention. The inside of the pipe is completely wetted by a plastic emulsion. For drying, the interior of the tube 1 is flowed through by a dried, tempered gas, in particular compressed air 40, in order to harden the plastic. The plastic particles are sintered by tempering via the heater 41. The compressed air 40 is fed in by a compressor 39 at the start of the tube 27. The process shown in FIGS. 3 and 4 can be repeated several times in order to increase a layer thickness of the plastic coating.

FIG. 5 shows a schematic representation of a production line 16, in which an already plastic-coated metal strip is formed into an elongated guide tube. The metal strip 3 here has a surface which is smoothly sealed by a plastic coating 8. This plastic-coated metal strip 3 is formed in a molding device 42 into the tube 1, so that the smooth sealed surface with the plastic coating 8 facing the interior 9 of the tube 1.

Claims

claims 1. laying element for a message transmission element with an elongated metallic guide tube (1) for guiding the message transmission element (5), an inner wall (4) of the guide tube facing the interior (9) of the guide tube being coated with plastic (8), which smoothly seals the inner wall. 2. Installation element according to claim 1, d a d u r c h g e k e n n z e i c h n e t that the plastic (8) is formed by a thermoset, thermoplastic or a resin mixture. 3. Laying element according to claim 1 or 2, that the metal part of the guide tube (1) is formed from copper, aluminum or sheet steel. 4. Installation element according to one of claims 1 to 3, d a d u r c h g e k e n n e e c h n e t that the plastic (8) has cavities which are filled with a friction-reducing material, in particular with oil, wax or fat. 5. laying element according to claim 4, d a d u r c h g e k e n n z e i c h n e t that the friction-reducing substance is introduced such that it is released when the transmission element is introduced. 6. Laying element according to one of claims 1 to 5, characterized in that the guide tube (1) is formed from a metal strip, the strip edges of the formed metal strip in such a manner are welded so that no root formation of welds (6) protrudes into the interior (9) of the guide tube. 7. A method for producing a laying element for a communication transmission element with an elongated metallic guide tube (1), in which an inner wall (9) of the guide tube facing inner wall (4) of the guide tube is provided with plastic (8), so that the inner wall of the guide tube is sealed with plastic. 8. The method according to claim 7, characterized in that for the formation of the guide tube (1) a plastic-coated metal strip (3) with a surface sealed by plastic (8) is formed into a tube (1), the smoothly sealed surface of the interior ( 9) facing the guide tube. 9. The method according to claim 7, d a d u r c h g e k e n n z e i c h n e t that the inner wall (4) of the guide tube after its formation with plastic (8, 10) is coated, so that the inner wall of the guide tube is smoothly sealed with plastic. 10. The method according to claim 9, so that the plastic is applied by powder coating (13, 15, 17, 19) to the inner wall of the shaped guide tube, in particular by a vortex sintering process. 11. The method according to claim 10, characterized in that the application of a plastic granulate (13) inside the tube is supported by an electrostatic field (12, 18, 20), in particular the plastic granulate (13) and the inner wall (4) being charged with opposite polarity to one another , 12. The method according to claim 10 or 11, characterized in that a plastic granulate (13) is applied with a hollow needle (17) arranged in the interior (9), which in the withdrawal direction (23) of the guide tube after a welding point (14) of the guide tube has an opening (15) for the exit of the plastic granules. 13. The method of claim 9, d a d u r c h g e k e n n z e i c h n e t that the plastic is applied by introducing a plastic emulsion (33) in the shaped guide tube (1). 14. The method according to claim 13, so that the guide tube (1) is stored on a drum, and during or after the introduction of the plastic emulsion (33) the drum is rotated. 15. The method according to claim 14, d a d u r c h g e k e n n z e i c h n e t that the guide tube (1) is tempered while rotating the drum. 16. The method according to any one of claims 13 to 15, so that the interior of the guide tube (1) is flowed through by a tempered gas (40), in particular dried air, in order to cure the plastic. 17. The method of claim 7, d a d u r c h g e k e n n z e i c h n e t that the plastic is applied as a self-contained ring structure and is self-supporting as a tube in a tube. 18. Method for laying a message transmission element within an elongated metallic guide tube (1), in which an inner wall (4) of the guide tube, which faces the interior (9) of the guide tube, is provided with plastic (8) so that the inner wall of the guide tube is smoothly sealed with plastic, and a message transmission element (5) is subsequently introduced into the interior of the guide tube by longitudinal movement.