AU2004223290A1

AU2004223290A1 - Connecting line, especially car connecting line and method for producing such a connecting line

Info

Publication number: AU2004223290A1
Application number: AU2004223290A
Authority: AU
Inventors: Heinz Haas; Ulrich Jung
Original assignee: Huber and Suhner AG
Current assignee: Huber and Suhner AG
Priority date: 2003-03-28
Filing date: 2004-02-02
Publication date: 2004-10-07
Also published as: EP1609157A1; WO2004086418A1; KR20050113264A; JP2006525900A

Description

IN THE MATTER OF an Australian Application corresponding to PCT Application PCT/CH2004/000053 I, Jacqueline Michelle HARDY BA (Hons), translator to RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, do solemnly and sincerely declare that I am conversant with the English and German languages and am a competent translator thereof, and that to the best of my knowledge and belief the following is a true and correct translation of the PCT Application filed under No. PCT/CH2004/000053. Date: 1 September 2005 J. M. HARDY For and on behalf of RWS Group Ltd WO 2004/086418 PCT/CH2004/00005 3 DESCRIPTION CONNECTING LINE, IN PARTICULAR A RAILROAD CAR CONNECTING LINE, AND A METHOD FOR PRODUCING SUCH A 5 CONNECTING LINE TECHNICAL FIELD The present invention relates to the field of cable 10 technology. It relates to a connecting line in accordance with the precharacterizing clause of claim 1 and to a method for producing such a connecting line. PRIOR ART 15 The technology in modern rail vehicles is placing ever greater demands on the components installed. In particular at high speeds, high dynamic forces (vibrational loads, pulsating loads, impact loads) 20 occur in high-speed trains (ICE3/ICNT/TGV etc.). These loads which are unusual in mechanical terms need to be withstood by the products installed there, in particular the freely suspended railroad car connecting 25 lines which are only a few meters long, without their main function (transmission of electrical power, control signals, safety monitoring) being impaired in the process, in particular in the region of the railroad car connections between the individual 30 railroad cars of such high-speed trains. In a railroad car connecting line between the railroad cars - as is depicted, for example, in the figures in WO-Al-01/68433 - all relevant electrical powers and 35 signals need to be capable of being transported unimpeded between the connected railroad cars. Such lines and cables therefore also contain, in addition to the robust elements used for power transmission, highly WO 2004/086418 - 2 - PCT/CH2004/000053 sensitive elements such as RFCs (coaxial cables), OWs (optical waveguides, optical fibers and POFs (polyoptical fibers)), pressure hoses for diverse media etc. These sensitive elements need to be protected as 5 much as possible during travel owing to the permanently high and asymmetrically occurring mechanical loads. It has long been known to form a fiberoptic conductor cable which can be subjected to mechanic loads by a 10 plurality of individual fiberoptic conductors being guided, with play, in a tubular jacket made from a suitable plastic (DE-Al-25 56 861). Such flexible fiberoptic conductor cables which can be subjected to high loads can advantageously be used as trunk cables 15 for optical information transmission systems in which the cables are subjected to a wide variety of environmental influences. The tubular jacket is in this case produced (extruded) around the fiberoptic conductors in a continuous process without the 20 fiberoptic conductors and their surrounding thin plastic layers being damaged. It is further known (US-A-4,976,509) to arrange such multi-fiber fiberoptic conductor cables, which have 25 been twisted with other (electrical) conductors and cables, in a flexible control cable, as is required for container crane systems. Owing to the long cable lengths required in these applications, the individual elements of the cables are first produced such that 30 they are complete per se and are then twisted with one another together with further packing and reinforcing elements and provided with an outer protective casing. As has already been mentioned initially, broadband 35 signal transmission elements in the form of coaxial cables, which are integrated in the railroad car connecting lines and are twisted with the remaining power supply cables and signal cables, are also used in WO 2004/086418 - 3 - PCT/CH2004/000053 the railroad car connecting lines of modern high-speed trains. In practice, it has now been shown that in particular the coaxial cables can be deformed locally or changed in another way by the extreme mechanical 5 loads acting on the railroad car connecting lines which are freely suspended between the railroad car bodies. This is noticeable from the decrease in the signal transmission quality over time which can impair reliable and faultfree operation of the high-speed 10 train. Other sensitive connecting elements can likewise be affected by the negative effects of the loads occurring during operation. SUMMARY OF THE INVENTION 15 The object of the invention is therefore to create a connecting line which is composed of individual cables which have been twisted with one another and whose sensitive elements are protected in a simple manner 20 more effectively against the effects of extreme mechanical loads, and to specify a method for its production. The object is achieved by the combined features of 25 claims 1 and 13. The essence of the invention consists in providing a dimensionally stable channel, which runs with the twisting and in which one of the cables which have been twisted with one another has been or is inserted with radial play, when producing the 30 connecting line. In contrast to the case of the known hybrid cables in which optical waveguides guided with play in a protective tube are twisted directly with the other cables, in accordance with the invention an empty tube or an empty channel is first arranged or provided 35 in the cable, and the connecting element to be protected is then inserted in this channel. This means that it is no longer necessary for a special, protected cable (with a protective tube) to first be produced. It WO 2004/086418 - 4 - PCT/CH2004/000 0 5 3 also ensures that the cable inserted in the channel can easily be withdrawn and possibly replaced. Finally, in the case of an empty channel being provided, different types of cables can be used, depending on the 5 requirement and application, without the cable design otherwise having to be changed. In the case of an empty channel being provided, it is thus optionally possible for a coaxial cable or a bundle of optical waveguides or other conductors to be inserted. The cable inserted 10 in the at least one channel is preferably a coaxial cable. In accordance with a first preferred embodiment of the invention, the at least one channel is formed by the 15 interior of a protective tube which has been twisted with the remaining cables. The shape, dimensions and material of the protective tube can in the process easily be optimized as regards protection (dimensional stability etc.) and workability (twisting ability). In 20 particular, the protective tube is made from a material with good sliding properties, preferably from a plastic. This ensures that the cable can be inserted in the empty protective tube- without any problems and easily, even in the case of a line length of several 25 meters. The protective tube is made in particular from a polyamide alloy and has a wall thickness of at least 0.8 mm. The protective tube preferably has a circular 30 cross section, and the inner diameter of the protective tube is at least 0.5 mm and no more than 2 mm larger than the outer diameter of the cable inserted in the protective tube. It is furthermore advantageous if the length of lay of the twisting is between 9 times and 12 35 times the bundle diameter of the twisted cables. With such a design, the cable in the protective tube has the necessary freedom of movement for it to be reliably protected against the external mechanical influences.

WO 2004/086418 - 5 - PCT/CH2004/000053 As an alternative to this, however, the at least one channel may also be formed by a cavity in an integral cable body. 5 One preferred embodiment of the method according to the invention is characterized by the fact that at least one protective tube is twisted with further protective tubes and/or cables in the first step, and the cable is 10 inserted in the at least one protective tube in the second step. As an alternative to this, an integral cable body having at least one channel extending in helical fashion in the longitudinal direction can be produced in the first step, and the cable can be 15 inserted in the at least one channel in the second step. Further embodiments are described in the dependent claims. 20 BRIEF EXPLANATION OF THE FIGURES The invention will be explained in more detail below with reference to exemplary embodiments in connection 25 with the drawing, in which: figure 1 shows a very simplified, perspective illustration of a section of an integral cable body having two empty channels which 30 have been "twisted" with one another for the purpose of inserting cables in accordance with a first preferred exemplary embodiment of the invention; 35 figure 2 shows an illustration, which is comparable to that in figure 1, of a section of a connecting line having two empty protective tubes which have been twisted therein for the WO 2004/086418 - 6 - PCT/CH2004/000053 purpose of inserting cables in accordance with a second preferred exemplary embodiment of the invention; 5 figure 3 shows the cable body shown in figure 1 having a coaxial cable inserted in one channel; figure 4 shows the connecting line shown in figure 2 having a coaxial cable inserted in one 10 protective tube; and figure 5 shows the cross section through an exemplary railroad car connecting line of a high-speed train having two protected coaxial cables 15 according to the invention. APPROACHES TO IMPLEMENTING THE INVENTION The present invention provides for sensitive elements 20 of the connecting line to be mechanically decoupled in the line. This means that a sufficiently large channel like cavity is formed within the connecting line or the connecting cable, this cavity extending in the longitudinal direction of the cable, and it being 25 possible for the individual elements or pretwisted elements to move freely axially and radially up to a certain degree in this cavity. This generally takes place by means of a protective tube which is installed in the connecting line and is made from a material with 30 good sliding properties (preferably plastic). The elements to be protected are then inserted in the protective tube. Possibly occurring forces on these elements can therefore be suppressed immediately. The number of protected or "normal" elements installed is 35 in principle arbitrary. The elements are worked together to form a twisted bundle; i.e. the elements are "twisted". As a result, the critical elements have an excess length which makes extension possible without WO 2004/086418 - 7 - PCT/CH2004/000053 significant mechanical load being placed on the element. In place of the elements which have been twisted in the form of a cable in the protective tubes, an extruded chamber system is also conceivable in which 5 the individual chambers or channels (round, honeycombed etc.) are arranged in spiral fashion and are fitted with individual elements or twisted elements. Figure 1 shows a simplified exemplary embodiment of 10 such an extruded chamber system. The starting point is an extruded (cylindrical) cable body 10 in which two channels 11, 12 having a circular cross section are arranged in a spiral ("twisted") arrangement. Of course, the channels 11, 12 may also have other cross 15 sectional shapes (rectangular, square, trapezoidal, the shape of a circle sector etc.) instead of the circular cross-sectional shape. More than two channels or else only one channel may likewise be provided. The cable body 10, of which only one short section is shown in 20 figure 1, is first extruded over a length which is expedient both in terms of cost and in terms of production engineering and then cut to length, as is required for the complete connecting line or railroad car connecting line. The "twisting" of the channels 11, 25 12 in the process ensures that there is sufficient cable length available in the complete line for the cables inserted in the channels 11, 12 not to be subjected to mechanical loads in the event of the line being stretched axially. 30 The inner diameter of the channels 11, 12 is selected such that the inserted cables are at a sufficient distance from the inner wall of the channels 11, 12 on all sides and are thus mechanically decoupled from the 35 cable body 10 without too much additional space being taken up in the process. In order to achieve this, the difference in diameter between the inner diameter of the channels 11, 12 and the outer diameter of the WO 2004/086418 - 8 - PCT/CH2004/000053 inserted cables should be in the range between 0.5 mm and 2 mm. Suitable materials for the cable body 10 are primarily plastics and plastic mixtures ("blends") which, on the one hand, can be worked easily and, on 5 the other hand, are at the same time flexible and dimensionally stable, and have good sliding properties on the surface such that the cables can be inserted in the channels 11, 12 without any difficulties even over a cable length of several meters. 10 As shown in figure 3, after extrusion of the cable body 10, for example a coaxial cable 19 is inserted in the channel 12, this coaxial cable 19 responding in a sensitive manner to mechanical loads and substantially 15 comprising a central inner conductor 22 and a concentric outer conductor (shield) 21 which is spaced apart from said inner conductor 22, the interspace between the two conductors being filled with a dielectric 23. Owing to the loose and spiral 20 arrangement of the coaxial cable 19 in the channel 12 of the connecting line 20, the coaxial cable 19 is almost completely mechanically decoupled from the cable body 10 in the event of the cable body 10 being strecthed, bent, subjected to torsion or impact loads 25 or the like. Local deformation of the concentric conductor arrangement 21, 22, 23 and its degrading influence on the cable properties are thus reliably avoided even under difficult conditions. It goes without saying that, in place of the coaxial cable 19, 30 other mechanically sensitive cables, conductors or lines, for example optical waveguides, can also be inserted in the channels 11, 12 and protected thereby. One particularly preferred exemplary embodiment of a 35 connecting line according to the invention is illustrated in figures 2 and 4. Figure 2 shows a very simplified illustration of the section of a connecting line in which two protective tubes 15, 16 which have WO 2004/086418 - 9 - PCT/CH2004/000053 been "twisted" with one another are arranged in an interior 14 surrounded by a jacket 13. The interiors 17, 18 of the protective tubes 15, 16 form the channels in which mechanically sensitive elements such as a 5 coaxial line 19 can be inserted in order to complete the connecting line 24, as shown in figure 4 and in an analogous manner to figure 3. The hollow-cylindrical protective tubes 15, 16 are made from a plastic mixture with good sliding properties, in particular a 10 thermoplastic PA/PE mixture. The protective tubes 15, 16 have a wall thickness of at least 0.8 mm. Their inner diameter is selected such that the free diameter space of the coaxial cable 19 in the protective tube 16, i.e. the difference between the inner diameter of 15 the protective tube 16 and the outer diameter of the coaxial cable 19, is between 0.5 mm and 2 mm. The protective tubes 15, 16 which are relatively rigid per se attain a certain degree of flexibility when twisted without losing their protective mechanical properties. 20 For reasons of simplicity, further conventional individual or pretwisted cables, which have been twisted with the protective tubes 15, 16 and thus form a bundle of cables with and without a protective tube 25 (cf. also figure 5), are not shown in figures 2 and 4. The length of lay, i.e. the twisting pitch per turn, is in this case preferably in a range between 9 times and 12 times the bundle diameter of the cable bundle. 30 The cross section through a hybrid railroad car connection cable for a high-speed train, as is used in practice, is depicted in figure 5. The connecting line or railroad car connecting line 30 in figure 5 is surrounded on the outside by a hollow-cylindrical 35 protective casing 32 made from a resistant TPE material. The outer diameter of the exemplary cable is approximately 30 mm. An electrically conductive EMC shield 26 is arranged on the inside of the protective WO 2004/086418 - 10 - PCT/CH2004/000053 casing 32. On the inside, the shield 26 is covered with a mechanically reinforcing intermediate layer 28. Six conventional, multi-core cables 25, 31, 33, 34, 35, 5 38 having two protective tubes 36 are twisted in the interior of the connecting line 30. A coaxial cable 37 is inserted in the protective tubes 36 in each case with radial play. The space between the twisted cables is partially filled with fillers 29 in the form of 10 tear-resistant threads or the like. The cables 31, 34 and 38 are designed in the same way. They each have 4 cores or conductors and are used as bus lines for the train. The cable 25 is a two-core bus line. The two coaxial cables 37 are conventional 75 Q cables having a 15 Cu braided wire as the inner conductor, a foamed dielectric and a shield made from Cu braiding. In this example, the coaxial cables 37 have an outer diameter of 3.8 mm. The inner diameter of the protective tubes 36 is considerably greater, as can clearly be seen in 20 figure 5. A connecting line according to the invention is distinguished from conventional solutions, in which all of the cables of the line are twisted fixedly with one 25 another, by having higher functional reliability and a longer life. In particular, it is flexible and has high fatigue strength under reversed bending stress. It is therefore particularly well suited as a moving connecting cable in railroad car connections in high 30 speed trains.

WO 2004/086418 - 11 - PCT/CH2004/000053 LIST OF REFERENCES 10 Cable body 11, 12 Channel (twisted) 5 13 Jacket 14 Interior 15, 16 Protective tube 17, 18 Interior (channel) 19 Coaxial cable 10 20, 24, 30 Connecting line (railroad car connecting line) 21 Shield (outer conductor) 22 Inner conductor 23 Dielectric 15 25, 31, 33 Cable 26 Shield 27, 28 Intermediate layer 29 Filler (e.g. thread) 32 Protective casing 20 34, 35, 38 Cable 36 Protective tube 37 Coaxial cable

Claims

1. A connecting line (20, 24, 30), in particular a railroad car connecting line for the power supply 5 and/or signal connection between the railroad cars of a train, which connecting line (20, 24, 30) comprises a plurality of cables (19, 25, 31, 33, 34, 35, 37, 38) which have been twisted with one another, characterized in that at least one dimensionally stable channel (11, 10 12; 17, 18), which runs with the twisting and in which one (19, 37) of the cables (19, 25, 31, 33, 34, 35, 37, 38) which have been twisted with one another has been inserted with radial play, is provided within the connecting line (20, 24, 30). 15

2. The connecting line as claimed in claim 1, characterized in that the cable inserted in the at least one channel (11, 12; 17, 18) is a coaxial cable (19, 37). 20

3. The connecting line as claimed in either of claims 1 and 2, characterized in that the at least one channel is formed by the interior (17, 18) of a protective tube (15, 16, 36) which has been twisted with the remaining 25 cables (25, 31, 33, 34, 35, 37, 38).

4. The connecting line as claimed in claim 3, characterized in that the protective tube (15, 16, 36) is made from a material with good sliding properties, 30 preferably from a plastic.

5. The connecting line as claimed in claim 4, characterized in that the protective tube (15, 16, 36) is made from a polyamide alloy. 35

6. The connecting line as claimed in claim 5, characterized in that the protective tube (15, 16, 36) has a wall thickness of at least 0.8 mm. WO 2004/086418 - 13 - PCT/CH2004/000053

7. The connecting line as claimed in one of claims 3 to 6, characterized in that the protective tube (15, 16, 36) has a circular cross section, and in that the 5 inner diameter of the protective tube (15, 16, 36) is at least 0.5 mm and no more than 2 mm larger than the outer diameter of the cable (19, 37) inserted in the protective tube (15, 16, 36). 10

8. The connecting line as claimed in one of claims 1 to 7, characterized in that the length of lay of the twisting is between 9 times and 12 times the bundle diameter of the twisted cables (19, 25, 31, 33, 34, 35, 37, 38). 15

9. The connecting line as claimed in either of claims 1 and 2, characterized in that the at least one channel (11, 12) is formed by a cavity in an integral cable body (10). 20

10. The connecting line as claimed in claim 9, characterized in that the cable body is made from a material with good sliding properties, preferably from a plastic. 25

11. The connecting line as claimed in claim 10, characterized in that the cable body (10) is made from a polyamide alloy. 30

12. The connecting line as claimed in one of claims 9 to 11, characterized in that the channel (11, 12) has a circular cross section, and in that the inner diameter of the channel (11, 12) is at least 0.5 mm and no more than 2 mm larger than the outer diameter of the cable 35 (19) inserted in the channel (11, 12).

13. A method for producing a connecting line as claimed in one of claims 1 to 12, characterized in WO 2004/086418

- 14 - PCT/CH2004/000053 that, in a first step, a line section of a predetermined length is produced which has at least one dimensionally stable, empty channel (11, 12; 17, 18), which extends in spiral fashion as a type of twisting 5 in the longitudinal direction of the line, for the purpose of accommodating a cable (19, 37), and in that, in a second step, a cable (19, 37) is inserted in the at least one empty channel (11, 12; 17, 18). 10 14. The method as claimed in claim 13, characterized in that a coaxial cable (19, 37) is inserted as the cable.

15. The method as claimed in either of claims 13 and 14, characterized in that at least one protective tube 15 (15, 16, 36) is twisted with further protective tubes and/or cables (25, 31, 33, 34, 35, 38) in the first step, and in that the cable (19, 37) is inserted in the at least one protective tube (15, 16, 36) in the second step. 20

16. The method as claimed in either of claims 13 and 14, characterized in that an integral cable body (10) having at least one channel (11, 12) extending in helical fashion in the longitudinal direction is 25 produced in the first step, and in that the cable (19) is inserted in the at least one channel (11, 12) in the second step.