DATA CABLE AND STRANDED CONDUCTOR

Abstract

A data cable has a specially formed stranded conductor, as a result of which the transmission properties of the data cable are significantly improved. The stranded conductor is surrounded by insulation and has an unpressed assembly composed of a plurality of individual wires which are of a same type and being embodied as external wires and being disposed around a center. The external wires are embodied with a non-round cross section, with a result that when viewed in cross section an extent of the external wires increases radially outward from the center.

Claims

1. A data cable, comprising: a data conductor having a stranded conductor surrounded by insulation, said stranded conductor having an unpressed assembly composed of a plurality of individual wires which are of a same type and being embodied as external wires and being disposed around a center, said external wires each being embodied with a non-round cross section, with a result that when viewed in cross section an extent of said external wires increases radially outward from the center.

2. The data cable according to claim 1, further comprising a shield surrounding said data conductor.

3. The data cable according to claim 2, wherein said data cable is a coaxial cable in which said stranded conductor and said shield are disposed concentrically.

4. The data cable according to claim 1, wherein said data conductor is one of two data conductors forming a wire pair.

5. The data cable according to claim 1, wherein said stranded conductor is free of a central conductor.

6. The data cable according to claim 1, further comprising a functional element disposed in the center of said stranded conductor.

7. The data cable according to claim 6, wherein said functional element is a strain relief element.

8. The data cable according to claim 6, wherein said functional element is a latent heat accumulator.

9. The data cable according claim 1, wherein said external wires each have a triangular cross-sectional shape.

10. The data cable according to claim 1, wherein said external wires have a cross-sectional shape with rounded corners.

11. The data cable according to claim 1, wherein said external wires have a cross-sectional shape with outwardly bent sides.

12. The data cable according to claim 1, wherein in each case two adjacent ones of said external wires touch one another in a punctiform fashion.

13. The data cable according to claim 1, wherein in each case two adjacent ones of said external wires touch one another over a surface.

14. A stranded conductor comprising: an unpressed assembly composed of a plurality of individual wires which are of a same type and are embodied as external wires and are disposed around a center which is free of a central conductor, said external wires are each embodied with a non-round cross section, with a result that when viewed in cross section an extent of said external wires increases radially toward an outside from the center.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

[0045] FIG. 1 is a diagrammatic, sectional view of a stranded conductor with an internal wire and with a plurality of external wires according to the invention;

[0046] FIG. 2 is an enlarged cross-sectional illustration of one of the external wires;

[0047] FIG. 3 is a sectional view of a data cable; and

[0048] FIG. 4 is a sectional view of a variant of the data cable.

DETAILED DESCRIPTION OF THE INVENTION

[0049] Referring now to the figures of the drawings in detail and first, particularly to FIG. 1 thereof, there is shown a data conductor 1 which is described by way of example below has a stranded conductor 2 which is constructed from seven individual wires in the exemplary embodiment, wherein six individual wires are arranged as external wires 4 around a center Z in which a central conductor, here an internal wire 6, is arranged. The internal wire 6 has here a circular cross section, and the external wires 4 are positioned evenly distributed around this internal wire 6. In one preferred non-illustrated variant, the internal wire 6 is dispensed with, i.e. the center Z is then free of an internal wire.

[0050] The external wires 4 are identical, i.e. configured identically and have a cross-sectional shape which corresponds in a good approximation to the shape of a Reuleaux triangle with rounded corners. This cross-sectional shape is illustrated in an enlarged form in FIG. 2, and is depicted together with an equilateral triangle with a side length L for purposes of comparison. In this way it is apparent that the cross-sectional shape of the external wires 4 has rounded corners based on a triangular shape. In addition, the sides are arched outward. In other words, the cross-sectional shape of the external wires 4 is constructed from two different circular-segment shapes, wherein the corners of the Reuleaux triangular shape are each formed by a circular segment shape with a radius RE, and wherein the sides of the Reuleaux triangular shape are each formed by a circular segment shape with a radius RS.

[0051] In the case of a stranded conductor 2 for ultrathin vehicle lines, the side length L is, for example, in the range from 0.25 mm-0.6 mm, in particular is approximately 0.4 mm. The radius RS is approximately ten times the radius RE and is, for example, 0.6 mm to 1 mm, in particular is 0.8 mm.

[0052] The assembly composed of external wires 4 and the internal wire 6 is configured in such a way that when considered in cross section one corner of each external wire 4 bears in a punctiform fashion on the internal wire 6, and in that a punctiform support, that is to say punctiform contact, is also provided between adjacent external wires 4.

[0053] The external wires 4 together form a closed outer layer 8 by which the center Z is completely enclosed. The outer layer 8 also has when viewed in cross section a circumferential contour which is circular in a good approximation, but a remaining interstice 10 is formed in each case in the intermediate region between two external wires 4 on the circumferential side. These interstices 10 are, however, relatively small compared to a stranded conductor according to the prior art in which external wires with a circular cross section are arranged around an internal wire which also has a circular cross section.

[0054] The data conductor 1 also has insulation 12 which surrounds the outer layer and which is usually applied by extrusion to the stranded conductor 2. By virtue of the selected cross-sectional shape of the external wires 4 and the resulting relatively small size of the interstices 10, the wall thickness 14 of the insulation 12 is, in a good approximation, constant when considered in the circumferential direction 16 and can, in particular, be made very thin.

[0055] In addition, it becomes clear from FIGS. 1 and 2 that the stranded conductor 2 has overall a particularly round circumferential contour. As a result, the stranded conductor 2 is particularly well suited for use in a data cable 18. Variants of such a data cable 18 are illustrated in FIGS. 3 and 4. In this context, the specific shape and arrangement of the external wires 4 result in particularly homogenous distributions of current and voltage which are conducted by means of the stranded conductor 2. The risk of partial discharges is significantly reduced and likewise the resistance of the current, resulting in overall relatively low losses.

[0056] The data cable 18 shown in FIG. 3 is embodied as a coaxial cable and has a stranded conductor 2, with a plurality of external wires 4 as in FIG. 1. However, there is no internal wire 6 arranged in the center Z but instead a functional element 20. The latter is embodied, for example, as a strain relief element and then as an aramide fiber or a steel cable. Alternatively, the functional element 20 is a latent heat accumulator. For this purpose, for example a thermal polymer-based buffer is used.

[0057] The stranded conductor 2 is in turn surrounded by the insulation 12 which is at the same time a dielectric 22 of the data cable 18 here. The stranded conductor 2 and the dielectric form the data conductor 1. A shield 24, e.g. a shielding film, a braid or a tape is arranged around the dielectric 22. The shield 24 is in turn surrounded by an external sheath 26. As a result of the particularly round circumferential contour of the stranded conductor 2, the distance between the external wires 4 and the shield 24 is particularly homogenous in the circumferential direction, that is to say it has a particularly low variance, as a result of which the transmission properties of the data cable 18 are significantly improved.

[0058] FIG. 4 shows a further data cable 18 which is embodied here with two wires, i.e. with two stranded conductors 2. In the case of these stranded conductors 2, both an internal wire 6 and a functional element 20 are dispensed with, with the result that an empty space is present in the center Z. The external wires 4 are each surrounded by insulation 12, with the result that overall two wires 28 are formed. These are combined in a common external sheath 26. In one non-illustrated variant, the two wires 28 are each additionally shielded or alternatively or additionally both wires 26 are surrounded by a common shield, in order to form a shielded wire pair. In addition, the two wires 28 are either twisted with one another to form a “twisted pair” or led parallel to one another as an “untwisted pair”.

[0059] The omission of the internal wire in the center Z has the advantage particularly during preparation that a crimp which is attached to a respective wire 28 divides the stranded conductor 2 symmetrically, i.e. the even number of external wires 4 is distributed uniformly onto the two partial chambers of the crimp during the squeezing process. As a result, a particularly uniform mechanical load is produced. At the same time, the data cable 18 is overall lighter in weight and requires less material for fabrication.