Power and / or control cable for mobile applications

Abstract

The present disclosure relates to a flexible cable (1) for mobile applications comprising: one or more insulated core wires (2, 3); a filler layer (4) surrounding the one or more insulated core wires (2, 3) having an outer surface (6) defining a filler layer outer perimeter (7) which substantially forms a closed convex polygonal chain having a plurality of line segments connecting consecutive vertices; and an outer jacket (8) surrounding and directly applied on the filler layer (4) having an outer surface (10) defining an outer jacket outer perimeter (11) which forms a continuous closed curve.

Description

Technical Field

[0001] This disclosure relates to a flexible power and / or control cable for mobile applications. In particular, this disclosure relates to cables suitable for, for example, three-phase AC and / or single-phase AC and / or DC facilities and / or cables including, for example, optical fibers, for transmitting signals or data. The cable of this disclosure is a flexible cable, for example, used for connecting movable parts of machine tools or any material handling equipment associated with high mechanical stress, frequent bending or torsional operations, or rapid motion with high acceleration. Background Technology

[0002] Flexible cables used in the above applications include, for example, an electrically insulating inner sheath made of rubber, which encloses multiple core wires, including, for example, phase conductors and / or optical fibers, and other possible components such as a grounding conductor, depending on the cable type. An outer sheath encloses the inner sheath. In cross-section, the outer surface of the inner sheath and the inner surface of the outer sheath have circular circumferences, thus the outer sheath tends to torsionally slide relative to the inner sheath under torsional stress. To avoid this slippage and possible separation of the outer sheath from the inner sheath, known flexible cables include anti-sway protection elements, such as composite wire embedded at the interface between the outer and inner sheaths.

[0003] US 2,583,026A discloses a cable comprising two stranded conductors, conductor insulation surrounding each conductor, and an outer sheath enclosing the entire cable. The conductor insulation is formed such that its outer surface is corrugated to include alternating ribs separated by grooves. The ribbed insulation is made of a rubber insulating compound, i.e., an elastomer. However, the combination of elastomers with a corrugated outer surface is problematic from a manufacturing point of view because it is difficult to fill the grooves, potentially resulting in poor mechanical properties. Furthermore, the corrugated shape with alternating ribs and grooves requires an appropriate width to avoid possible rubber breakage.

[0004] Other special cables not used for mobile applications may have an outer sheath surrounding a non-circular layer, as shown in some of the examples listed below.

[0005] CN 110491590A discloses a halogen-free low-smoke flame-retardant cable with three conductors, wherein the cross-section of the first insulating sleeve surrounding the conductors is annular, the cross-section of the second insulating sleeve is a special annular shape with a square outer surface and a circular inner surface, and the cross-section of the flame-retardant outer sleeve is a hexagonal annular shape.

[0006] CN 206075924U discloses a high-strength flame-retardant and fire-resistant cable, which includes an insulation layer with a cross-section of an octagon, and eight cable cores disposed within the cross-section are an octagonal polyester skeleton, wherein the insulation wire of the cable core has a cross-section of an octagon, and the eight cable cores are arranged in an appropriate order.

[0007] EP 3 637 164A1 discloses a bulletproof gun-type fiber optic loose tube cable, which includes a non-metallic central strength element, an outer sheath made of PE, an inner sheath, a water-swellable yarn, and a protective strength element comprising flat fiber-reinforced plastic elements arranged in a polygonal manner. Summary of the Invention

[0008] Therefore, the applicant aims to provide a flexible cable with improved torsional resistance for use in movable parts.

[0009] This objective is achieved by a flexible cable having a filler layer that accommodates one or more insulated cores and has a polygonal outer profile, and an outer sheath with an outer circular profile that is directly applied to the outer polygonal profile of the filler layer.

[0010] Experimental tests show that, under the same torsional stress conditions, the torsional movement of the outer sheath relative to the inner filler layer is significantly lower than the torsional movement of the outer sheath relative to the inner sheath in comparable flexible cables according to the prior art. Like the flexible cables according to the prior art, the flexible cable according to this disclosure has rounded corners, particularly circular ones. Therefore, the flexible cables of the prior art can be easily replaced by the flexible cable of this disclosure, which has higher torsional strength.

[0011] Therefore, this disclosure relates to a flexible cable for mobile applications, comprising:

[0012] - One or more insulated core wires;

[0013] - A filler layer surrounding one or more insulated core wires, having an outer surface defining the outer perimeter of the filler layer, the outer perimeter of the filler layer substantially forming a closed convex polygon chain with multiple line segments connecting continuous vertices; and

[0014] - An outer sheath, which surrounds the packing layer and is applied directly to the packing layer, has an outer surface that defines the outer perimeter of the outer sheath, the outer perimeter of the outer sheath forming a continuous simple closed curve.

[0015] In one embodiment, the outer sheath has an inner surface that is radially opposite to the outer surface of the outer sheath, wherein the inner surface of the outer sheath is in direct contact with and coincides with the outer surface of the filler layer.

[0016] In one embodiment, the flexible cable includes an anti-sway device at the interface between the inner surface of the outer sheath and the outer surface of the filler layer.

[0017] In one embodiment, the anti-sway device includes one or more embedded lines.

[0018] In one embodiment, the line segment of the outer perimeter of the packing layer is a straight line segment or a curved segment.

[0019] In one embodiment, the curved segment at the outer perimeter of the filler layer is convex.

[0020] In one embodiment, the vertex of the outer perimeter of the filler layer is shaped as the point where two continuous line segments intersect.

[0021] In one embodiment, the apex of the outer perimeter of the filler layer is rounded.

[0022] In one embodiment, the number of vertices of the outer perimeter of the filler layer is at least four, preferably in the range of six to twelve, wherein six and twelve are included in this range.

[0023] In one embodiment, the outer perimeter of the filler layer is substantially octagonal.

[0024] In one embodiment, the filler layer is formed by extrusion around one or more insulated core wires.

[0025] In one embodiment, the outer perimeter of the outer sheath is substantially circular.

[0026] In one embodiment, one or more insulated core wires include at least an electrical conductor.

[0027] In one embodiment, the outer sheath is applied to the filler layer by extrusion. In one embodiment, the filler layer and the outer sheath are made of polymers selected from the group consisting of:

[0028] - Crosslinked elastomers, including any of synthetic rubber, polychloroprene, chlorosulfonated polyethylene, and halogen-free crosslinked elastomers;

[0029] - Thermoplastic polymers, including any of polyethylene, cross-linked polyethylene, polypropylene, polyvinyl chloride, polyurethane, polyester, and halogen-free thermoplastic polymers.

[0030] - and any combination thereof.

[0031] In one embodiment, both the filler layer and the outer sheath are made of cross-linked elastomer. Attached Figure Description

[0032] Other features and advantages will become more apparent from the following description of some embodiments given by way of example with reference to the accompanying drawings, in which:

[0033] Figure 1 A cross-sectional view of a flexible cable according to an embodiment of the present disclosure is shown;

[0034] Figure 2 A cross-sectional view of a flexible cable according to another embodiment of the present disclosure is shown. Detailed Implementation

[0035] In the following description, the same reference numerals are used for similar typical elements when they are drawn in different figures.

[0036] For the purposes of this specification and the appended claims, the word "a" or "an" should be understood to include one or more, and the singular includes the plural, unless it is obvious that it has a different meaning. This is done merely for convenience and to give the general meaning of this disclosure.

[0037] This disclosure can be implemented in at least one of the foregoing aspects by alternatively combining one or more of the following embodiments.

[0038] Reference Appendix Figures 1-2 The flexible cable is indicated by reference numeral 1 in the accompanying drawings. The flexible cable 1 comprises one or more cores, which can be of different types. For example, the one or more cores may include a three-phase AC conductor and / or a single-phase AC conductor and / or a DC conductor and / or a data transmission device such as an optical fiber. Depending on the type, each core may include additional layers such as shielding and electrical insulation, as will be apparent to those skilled in the art. However, most embodiments of the invention include at least one electrically insulated core comprising a power conductor having a diameter of at least 25 mm. 2 The conductor cross-section. In Figure 1-2 In the embodiment shown, by way of example only, cable 1 includes three insulated AC conductors 2 arranged in a triangle and three insulated grounding conductors 3 arranged in a triangle.

[0039] The flexible cable 1 includes a filler layer 4 encapsulating one or more insulated core wires. The filler layer 4 includes an annular body extending longitudinally along the length of the cable, accommodating one or more core wires in its hollow portion, and the annular body having an inner surface 5 facing the core wires and an outer surface 6 radially opposite to the inner surface 5.

[0040] In a cross-section on a plane orthogonal to the longitudinal axis of cable 1 (corresponding to the longitudinal axis of the annular filler layer 4), the outer surface 6 defines the outer perimeter 7 of the filler layer, which substantially forms a closed polygonal chain having multiple line segments connecting consecutive vertices. The closed polygonal chain is convex, i.e., the exterior angle α at all vertices is greater than 180° (see [reference]). Figure 1 This construction improves the mechanical properties of the cable without creating protrusions or grooves in the filler layer 4.

[0041] The line segment can be a straight line segment or a curved segment (i.e., an arc), such as a convex curve segment.

[0042] The term "vertex" can be interpreted according to a strict geometric definition: the point where two consecutive straight lines or curves intersect. According to this interpretation, at least macroscopically, a vertex does not have a finite radius of curvature. Alternatively, vertices are rounded, meaning they contain an arc connecting two consecutive line segments. In embodiments that include both curved segments and rounded vertices, the radius of curvature of a rounded vertex is smaller than that of a curved segment.

[0043] From the definitions of "line segment" and "vertex" given above, it can be concluded that the outer perimeter 7 of the filler layer does not necessarily form a geometrically ideal closed polygonal chain, but the outer perimeter 7 of the filler layer can approximate a geometrically ideal closed polygonal chain (the above "basically forming a closed polygonal chain" should be interpreted in this sense).

[0044] exist Figure 1 and Figure 2 In the example, the vertex is the point of a continuous straight line segment connecting the outer perimeter 7 of the filler layer.

[0045] The number of vertices depends on the number, diameter, and arrangement of the core wires. In one embodiment, the number of vertices is at least four, preferably in the range of six to twelve (where six and twelve are considered to be included in the range of six to twelve). Figure 1 and Figure 2 In a typical implementation, the outer perimeter 7 of the filler layer essentially defines a regular octagon with 8 vertices.

[0046] The filler layer 4 is deformable and can be formed by extrusion around the core wire.

[0047] The flexible cable 1 also includes an outer sheath 8 that encapsulates the filler layer 4 and is applied directly to the filler layer 4. The outer sheath 8 can be formed, for example, by extruding around the filler layer 4 in a step after extruding the filler layer 4.

[0048] The outer sheath 8 includes an annular body extending longitudinally along the cable length and accommodating the filler layer 4 in its hollow portion. The outer sheath 8 has an inner surface 9 facing the outer surface 6 of the filler layer 4 and an outer surface 10 radially opposite to the inner surface 9. In a cross-section on a plane orthogonal to the longitudinal axis of the cable 1 (corresponding to the longitudinal axis of the outer sheath 8), the outer surface 10 defines an outer sheath perimeter 11 forming a continuous closed curve. In one embodiment, the outer sheath perimeter 11 corresponds to the cable perimeter. Unlike the outer perimeter 7 of the filler layer 4, the outer sheath perimeter 11 has no apex. In one embodiment, the outer sheath perimeter 11 is substantially circular, where "substantially" means similar to what has been discussed with respect to the outer perimeter 7 of the filler layer, i.e., the outer sheath perimeter 11 can be a regular circle or can be approximately a regular circle.

[0049] Due to the process of applying the outer sheath 8 to the filler layer 4 (particularly through extrusion), once the cable 1 is formed, the inner surface 10 of the outer sheath 8 substantially coincides with the outer surface 6 of the filler layer, particularly with the outer perimeter 7 of the filler layer. In other words, the inner surface 10 of the outer sheath 8 defines the inner perimeter of the outer sheath, which substantially forms the same closed polygonal chain formed by the outer perimeter 7 of the filler layer. Therefore, the vertices of the outer perimeter 7 of the filler layer act as anchor points for the outer sheath 8, thus the outer sheath 8 is torsionally locked to the filler layer 4.

[0050] The filler layer 4 and / or the outer sheath 8 may be made of a polymer, preferably selected from the group consisting of crosslinked elastomers (such as synthetic rubber, polychloroprene, chlorosulfonated polyethylene, halogen-free crosslinked elastomers) and thermoplastic polymers (such as polyethylene, crosslinked polyethylene, polypropylene, polyvinyl chloride, polyurethane, polyester, halogen-free thermoplastic polymers). Even without explicit reference, the filler layer 4 and the outer sheath 8 may be made of any combination of the above materials. Possible combinations include:

[0051] - The filler layer 4 is made of synthetic rubber and the outer sheath 8 is made of halogen-free cross-linked elastomer;

[0052] - The filler layer 4 is made of synthetic rubber and the outer sheath 8 is made of polychloroprene rubber;

[0053] - The filler layer 4 is made of polyvinyl chloride and the outer sheath 8 is made of polyurethane;

[0054] - The filler layer 4 is made of polyurethane and the outer sheath 8 is made of polyurethane;

[0055] - Both the filler layer 4 and the outer sheath 8 are made of cross-linked elastomer.

[0056] In one embodiment, the inner surface 9 of the outer sheath 8 is in direct contact with the outer surface 6 of the filler layer 4. Figure 1 ).

[0057] In one embodiment, the cable 1 includes an anti-sway device at the interface between the inner surface 9 of the outer sheath 8 and the outer surface 6 of the filler layer 4. Figure 2 Preferably, the anti-sway device includes one or more embedded lines 12, which act as friction devices between the inner surface 9 of the outer sheath 8 and the outer surface 6 of the filler layer 4.

Claims

1. A flexible cable (1) for mobile applications involving torsional stress, comprising: -One or more insulated core wires (2, 3); - An extruded polymer filler layer (4) surrounds the one or more insulating core wires (2, 3) and has an outer surface (6) defining an outer perimeter (7) of the filler layer, the outer perimeter (7) of the filler layer substantially forming a closed convex polygonal chain with multiple line segments having connected vertices. and - An outer sheath (8) that surrounds the filler layer (4) and is applied directly to the filler layer (4) has an outer surface (10) that defines a substantially circular outer perimeter (11) of the outer sheath. The filler layer (4) also has an inner surface (5) that is radially opposite to the outer surface (6) of the filler layer (4), wherein in a cross section on a plane orthogonal to the longitudinal axis of the flexible cable (1), the outer surface (6) of the filler layer (4) is polygonal in shape, and the inner surface (5) of the filler layer (4) is in direct contact with the outer surface of the one or more insulated core wires (2, 3).

2. The flexible cable (1) according to claim 1, wherein, The outer sheath (8) has an inner surface (9) that is radially opposite to the outer surface (10) of the outer sheath (8), wherein the inner surface (9) of the outer sheath (8) is in direct contact with and consistent with the outer surface (6) of the filler layer (4).

3. The flexible cable (1) according to claim 1, wherein, The outer sheath (8) has an inner surface (9) that is radially opposite to the outer surface (10) of the outer sheath (8), and the flexible cable (1) further includes an anti-sway device at the interface between the inner surface (9) of the outer sheath (8) and the outer surface (6) of the filler layer (4).

4. The flexible cable (1) according to claim 3, wherein, The anti-sway device includes one or more embedded lines (12).

5. The flexible cable (1) according to any one of claims 1-4, wherein, The line segment of the outer perimeter (7) of the filler layer is a straight line segment or a curved segment.

6. The flexible cable (1) according to claim 5, wherein, The curved segment of the outer perimeter (7) of the filler layer is convex.

7. The flexible cable (1) according to any one of claims 1-4, wherein, The vertex of the outer perimeter (7) of the filler layer is formed as the point where two continuous line segments intersect.

8. The flexible cable (1) according to any one of claims 1 to 4, wherein, The vertex of the outer perimeter (7) of the filler layer is rounded.

9. The flexible cable (1) according to any one of claims 1-4, wherein, The number of vertices of the outer perimeter (7) of the filler layer is at least 4.

10. The flexible cable (1) according to any one of claims 1-4, wherein, The outer perimeter (7) of the filler layer is basically formed as an octagon.

11. The flexible cable (1) according to any one of claims 1-4, wherein, The outer sheath (8) is applied to the filler layer (4) by extrusion.

12. The flexible cable (1) according to any one of claims 1-4, wherein, The filler layer (4) and the outer sheath (8) are made of polymers selected from the group consisting of crosslinked elastomers, thermoplastic polymers, and any combination thereof.

13. The flexible cable (1) according to claim 12, wherein, The crosslinked elastomer includes synthetic rubber.

14. The flexible cable (1) according to claim 12, wherein, The crosslinked elastomer includes any of polychloroprene, chlorosulfonated polyethylene, and halogen-free crosslinked elastomers.

15. The flexible cable (1) according to claim 12, wherein, The thermoplastic polymer includes any of polyethylene, polypropylene, polyvinyl chloride, polyurethane, and polyester.

16. The flexible cable (1) according to claim 12, wherein, The thermoplastic polymer includes cross-linked polyethylene.

17. The flexible cable (1) according to claim 12, wherein, The thermoplastic polymer includes halogen-free thermoplastic polymers.

18. The flexible cable (1) according to any one of claims 1-4, wherein, Both the filler layer (4) and the outer sheath (8) are made of cross-linked elastomer.

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