ELECTRICAL CABLE HAVING A SURFACE FACILITATING THEIR INSTALLATION

Abstract

A lubricated cable includes at least one elongated electrical conductor, at least one outer layer surrounding said elongated electrical conductor, and at least one lubrication layer surrounding said outer layer. The lubrication layer is obtained from a lubrication composition having naphtha petroleum.

Claims

1. A lubricated cable comprising: at least one elongated electrical conductor, at least one outer layer surrounding said elongated electrical conductor and at least one lubrication layer surrounding said outer layer, said lubrication layer being obtained from a lubrication composition comprising naphtha petroleum.

2. The lubricated cable according to claim 1, wherein the lubrication composition comprises at least 50% by weight of naphtha petroleum relative to the total weight of the lubrication composition.

3. The lubricated cable according to claim 1, wherein the lubrication composition possesses a kinematic viscosity, at 25° C., lower than 30 mm.sup.2/s.

4. The lubricated cable according to claim 1, wherein the lubrication composition has a specific gravity, at 20° C., in the range of 0.72 to 0.82.

5. The lubricated cable according to claim 1, wherein the lubrication layer has a thickness in the range of 1 to 50 μm.

6. The lubricated cable according to claim 1, wherein the outer layer is an outer protective sheath.

7. The lubricated cable according to claim 1, wherein the outer layer, notably the outer protective sheath, is a thermoplastic layer.

8. The lubricated cable according to claim 7, wherein the outer layer, notably the outer protective sheath, is based on polyamide.

9. The lubricated cable according to claim 1, wherein the outer layer, notably the outer protective sheath, has a thickness in the range of 0.05 to 0.50 mm.

10. The lubricated cable according to claim 1, wherein the lubrication layer is the outermost layer of the lubricated cable.

11. The lubricated cable according to claim 1, wherein the lubrication layer is in direct contact with the outer layer, notably the outer protective sheath.

12. The lubricated cable according to claim 1, wherein said lubricated cable comprises at least one insulating layer surrounding the elongated electrical conductor, the outer layer, notably the outer protective sheath, surrounding said insulating layer.

13. The lubricated cable according to claim 12, wherein the insulating layer is a thermoplastic layer.

14. The lubricated cable according to claim 13, wherein the insulating layer is based on polyvinyl chloride.

15. The lubricated cable according to claim 12, wherein the insulating layer has a thickness in the range of 0.20 to 1.50 mm.

16. A process for manufacturing a lubricated cable according to claim 1, wherein said process comprises a step of applying, notably by spraying, the lubrication composition at the surface of the outer layer, notably at the surface of the outer protective sheath.

17. The process according to claim 16, wherein said process further comprises a step of drying the lubrication composition once applied at the surface of the outer layer, notably at the surface of the outer protective sheath, to form the lubrication layer.

Description

DETAILED DESCRIPTION

Examples

[0094] The present invention is described in further detail in the following examples which are not in any way intended to limit the scope of the present invention as claimed. In addition, it will appear to a person skilled in the art that various modifications may be made to the disclosed embodiments, and that such modifications are intended to be within the scope of the present invention.

Example 1

[0095] In the example 1, a cable A comprises an elongated electrical conductor made of copper and having a diameter of 1.610 mm, said conductor being surrounded by an insulating layer made of PVC and having a thickness of 0.38 mm, said insulating layer being surrounded by a polyamide outer protective sheath having a thickness of 0.10 mm.

[0096] The cable A is coated by a lubrication composition commercialized by RichardsApex under the reference “V-4B CPD” to form a lubrication layer having a thickness of 5 μm, said lubrication layer surrounding the outer protective sheath.

[0097] The “V-4B CPD” lubrication composition comprises at least 50% by weight of naphtha petroleum, relative to the total weight of the lubrication composition; and possesses a kinematic viscosity, at 25° C., equal to 2.8 mm.sup.2/s (measured according to ASTM standard D445) and a specific gravity, at 20° C., equal to 0.77 (measured according to ASTM standard 891B).

Example 2

[0098] In the example 2, a cable B comprises an elongated electrical conductor made of copper and having a diameter of 2.033 mm, said conductor being surrounded by an insulating layer made of PVC and having a thickness of 0.38 mm, said insulating layer being surrounded by a polyamide outer protective sheath having a thickness of 0.10 mm.

[0099] The cable is coated by a lubrication composition commercialized by RichardsApex under the reference “V-4B CPD” to form a lubrication layer having a thickness of 5 μm, said lubrication layer surrounding the outer protective sheath.

Example 3

[0100] In the example 3, a cable C comprises an elongated electrical conductor made of copper and having a diameter of 2.558 mm, said conductor being surrounded by an insulating layer made of PVC and having a thickness of 0.51 mm, said insulating layer being surrounded by a polyamide outer protective sheath having a thickness of 0.10 mm.

[0101] The cable is coated by a lubrication composition commercialized by RichardsApex under the reference “V-4B CPD” to form a lubrication layer having a thickness of 5 μm, said lubrication layer surrounding the outer protective sheath.

Comparative Example 1

[0102] In the comparative example 1, a cable D comprises an elongated electrical conductor made of copper and having a diameter of 1.610 mm, said conductor being surrounded by an insulating layer made of PVC and having a thickness of 0.38 mm, said insulating layer being surrounded by a polyamide outer protective sheath having a thickness of 0.10 mm.

Comparative Example 2

[0103] In the comparative example 2, a cable E comprises an elongated electrical conductor made of copper and having a diameter of 2.558 mm, said conductor being surrounded by an insulating layer made of PVC and having a thickness of 0.51 mm, said insulating layer being surrounded by a polyamide outer protective sheath having a thickness of 0.10 mm.

[0104] Tests

[0105] To compare the friction coefficient of the cables coated with a lubrication composition (i.e. examples 1 to 3 according to the present invention) with the friction coefficient of the cables which are not coated with a lubrication composition (i.e. comparative examples 1 and 2), a pulling test was performed by pulling cables in a PVC pipe.

[0106] To perform this test, cables A to E having a length of 9 m are pulled from a PVC pipe. The maximum and minimum forces applied (force max and force min, respectively) are measured by a dynamometer.

[0107] The results are reported in Table 1.

TABLE-US-00001 TABLE 1 Lubrication composition Force max Force min Cable A Yes 5.8 kgf 4.6 kgf Cable B Yes 6.7 kgf 5.7 kgf Cable C Yes 17.4 kgf 5.8 kgf Cable D No 9.2 kgf 7.4 kgf Cable E No 25.2 kgf —

[0108] These results show that a reduction of the pulling force applied is comprised between 20% and 40% when the cables possess a lubrication layer according to the present invention. Said lubrication layer therefore improves the friction coefficient of the cable.