Optical fiber or metallic conductor cable with grooved outer coating

Abstract

The invention relates to a grooved outer coating comprising an outer sheath (20) provided with an inner cavity (21) housing optical fibers (11) or metallic conductors (12) grouped into a core (10). The outer sheath (20) has a circular outer contour and is provided with at least two trapezoidal radial grooves (13), which are continuous and angularly spaced from each other, defining a detachable sheath portion (20a) in order to define a window (J) for access to the core (10), and a base that remains separated from the cavity (21) by a breakable circumferential arc-shaped bridge (14).

Description

"Fiber optic cable or metallic conductor cable with grooved outer sheath" Innovation field

[0001] The present innovation relates to fiber optic or metallic conductor cables used in aerial or ducted data transmission networks, said cables comprising a core of fiber optics or metallic conductors that is loosely or tightly enclosed by an outer sheath that defines the grooved outer coating. Background of innovation

[0002] The usual installation techniques, whether aerial or in ducts, for these optical or metallic cables, require installation teams to use a ripping cord or cutting tools (utility knife, scissors, roller) to open the outer sheath, so that the installer can access the cable core and thus its optical fibers or metallic conductors.

[0003] Cables with rectangular or oval cross-sections, usually equipped with opposing grooves to facilitate tearing the outer sheath, are still known in the market. However, they do not allow the outer sheath to be opened manually, i.e., without the use of cutting tools or a tearing cord, either at an extreme or tip region of the cable or in a median region of an aerial horizontal span between poles or a vertical span in an internal installation, for example, along the floors of an apartment building.

[0004] In addition to featuring a tear groove that serves only as a guide and to some extent facilitates the operation of opening the outer cover to its extreme or intermediate position, Requiring the use of cutting tools and / or ripping cords to complete the operation, these well-known polygonal cross-section cables are usually incompatible with the fittings of many installations where circular cross-section cables are required.

[0005] There are also known fiber optic cables or metallic conductors with a circular cross-section featuring a construction in which the outer sheath lacks grooves to guide and / or facilitate tearing, requiring operator care and special tools to access the cable core by removing detachable internal elements. Constructions with these characteristics can be observed in documents US8520992 B2, CN 101943782 A and CN 105445877 A. Innovation Summary

[0006]

[0006] Due to the limitations of known solutions, the present innovation aims to provide a cable of optical fibers or metallic conductors, with the fibers or conductors grouped in a core surrounded, with or without slack, by an outer sheath of circular cross-section, compatible with market accessories and provided with optional longitudinal tensile elements and also with radially angularly spaced grooves designed to allow a directed manual tearing, extreme or median, of a detachable sheath portion defined between two adjacent radial grooves and sufficient to ensure easy access to the cable core, without the need for a tear cord.

[0007] The grooved cable that is the subject of this innovation enables quick access to the fibers for fusion or Connectorization without the need to open conduits, in addition to allowing for operational cost reductions in the installation of fiber optic cables or metallic conductors, as it eliminates the need for special tools to reach the cable core, particularly when accessed from the ends. Brief description of the drawings

[0008] The innovation will be described below, with reference to the attached drawings, given as examples of possible cable configurations, in which:

[0009] Figure 1 represents a cross-sectional view of a cable constructed according to a first configuration in which the outer sheath is provided with only one pair of longitudinal radial grooves;

[0010] Figure 2 illustrates a cross-section of the cable from Figure 1, after a portion of the outer sheath has been torn; and

[0011] Figure 3 represents a cross-sectional view of a cable constructed according to a second configuration in which the outer sheath is provided with two pairs of longitudinal radial grooves. Description of the innovation

[0012] As already mentioned and illustrated in the drawings, the present invention provides a cable of optical fibers or metallic conductors comprising a core 10 defined by a plurality of optical fibers 11 or metallic conductors 12 which, in the examples illustrated in Figures 1 and 2, are grouped in a core 10 arranged, with radial clearance, inside a cavity 21 defined within an outer sheath 20 of circular outer contour and formed in a Suitable polymers, such as polyethylene, with characteristics of easy cleavage and the necessary resistance to mechanical and environmental agents, are needed to remain operational throughout their service life in outdoor installations or in pipelines.

[0013] Optical fibers 11 may have different diameters and have "tight" insulation and may also be arranged in a "ribbon" format, with the cavity 21 of the outer sheath 20 being able to house additional wires or water absorption elements (not shown), positioned next to the optical fibers 11.

[0014] The outer sheath 20, made of a suitable polymer, is applied over the core 10 by extrusion, with a circular cross-section contour for compatibility with market accessories, the outer sheath 20 protecting the optical fibers 11 and the metallic conductors 12 against damage inside the cavity 21.

[0015] In the illustrated construction, the outer sheath 20 also encloses tensile elements 30, metallic or dielectric of high tenacity, arranged longitudinally embedded in the outer sheath 20, in opposite positions and coplanar with the geometric axis of the grooved cable in question. It should be understood that the tensile elements 30 may also be positioned internally to the outer sheath 20, inside the cavity 21 and externally to the core 10.

[0016] The provision of traction elements 30 is particularly, but not exclusively, suitable for aerial network installations, where the slotted cable remains horizontally suspended between poles, in spans whose dimensions may require a structure that prevents the optical fibers 11 from being exposed to tensile forces. excessive.

[0017] According to the innovation in question, the outer sheath 20 is provided, along its longitudinal extension, with at least two radial grooves 13, continuous and angularly spaced apart from each other by a circumferential distance corresponding to a detachable sheath portion 20a which, when separated from the cable (figure 2), defines, in the outer sheath 20, a window J with circumferential extension for access to the core 10.

[0018] The grooved cable may be provided with tensile elements 30 embedded in the outer sheath 20, in which case the detachable sheath portion 20a, defined by the angular spacing between two adjacent radial grooves 13, embeds within it a respective metallic or dielectric tensile element 30.

[0019] In the construction illustrated in Figures 1 and 2, the two radial slots 13 are positioned in radial directions offset by 90°, giving the slotted cable a "fish" shape. However, it should be understood that the phase angle between two adjacent slots 13 may vary, plus or minus, depending on the diameter of the slotted cable, the polymeric material forming the outer sheath 20, and the construction of the core 10 in relation to the inner contour of the outer sheath 20, to allow the detachable sheath portion 20a to correspond to a window J sufficient for operator access to the optical fibers 11 or the metallic conductors 12 of the core 10, particularly when access to a median region of a slotted cable span is required, in horizontal installations between poles or vertical installations between floors of a building.

[0020] Each groove 13 has a trapezoidal shape, open and widened to the outer circular contour of the outer cover 20 and having its opposite sides forming an angle of 20° to 70°, generally 45°, to facilitate grip by the operator's fingers during the tearing operation, for radial separation of the detachable cover portion 20a, as illustrated in figure 2.

[0021] Thus, the bottom of each groove 13, which defines the smaller base of the trapezoidal shape, remains separated from the cavity 21, housing the core 10, by a breakable circumferential arc-shaped bridge 14, having a radial thickness "A" dimensioned to provide adequate resistance to the outer shell 20, while at the same time facilitating its breakage by the operator during a tearing operation.

[0022] The minimum radial thickness "A" of each bridge 14 is determined according to the properties of the cable material, generally having a nominal value of 0.4 mm, with a tolerance of ± 0.3 mm. This value can be adjusted according to the hardness of the material used, being reduced for more rigid materials and increased for less rigid materials, thus ensuring the structural and functional integrity of the cable. The radial thickness "A" of the bridges 14 may correspond to their circumferential extent "B" at the bottom of each groove 13, with the same tolerances.

[0023] Figure 3 illustrates a constructive variation according to which the outer sheath 20 is provided with four grooves 13 offset from each other by 90°, defining two pairs of grooves 13, each pair forming between them a detachable sheath portion 20a that surrounds a respective traction element 30. This constructive variant, which gives the cable a cross-section in the shape of The term "Maltese cross" indicates that the number of slots 13 can vary depending on the diameter of the slotted cable and even the number of tensile elements 30, provided that two adjacent slots define a detachable sheath portion 20a that can define, in the outer sheath 20, a window J of sufficient circumferential dimension and suitable for access to the optical fibers 11 or the metallic conductors 12 of the core 10, either at one end of the latter or in a median region in a horizontal span between poles or in a vertical span between the floors of a building.

[0024] The grooved cable in question allows the operator, working on the telecommunications network, to easily tear the outer sheath 20 at either end of the cable or, especially, in a median region of a span, simply by applying manual tearing force to two adjacent grooves 13, with the operator pulling radially outwards and together with a respective traction element 30 if present, the respective detachable sheath portion 20a (figure 2), to open a window J in the outer sheath and thus easily, quickly and safely access the core 10 and perform the "splicing" of the optical fibers 11 or metallic conductors 12 for subdivision (splicing) with other optical fiber cables or metallic conductors 12 for installation inside each floor of a building, as occurs with FTTA networks.

[0025] The grooved cable in question enables cost reductions and increased operational safety in the installation of fiber optic cables 11 or metallic conductors 12 in data transmission networks, as it allows the outer sheath 20 to be opened manually, without the need for special tools or a rip cord, using only a pair of radial grooves 13 to direct the rip and expose the optical fibers 11 or metallic conductors 12 to the operator.

[0026] The cable of the present invention has the advantage of maintaining a circular contour and eliminating the need for ripping cords to open the ends, as well as special tools for tearing portions of the sheath in areas between horizontal or vertical gaps. This allows the optical fibers 11 to be ready for fusion or connectorization once the core is accessed through the J-window, without the need to open a "Loose" tube.

Claims

CLAIMS 1. Fiber optic or metallic conductor cable with grooved outer sheath comprising an outer sheath (20) provided with an inner cavity (21) housing optical fibers (11) or metallic conductors (12) grouped in a core (10), the cable being characterized in that the outer sheath (20) has a circular outer contour, being provided with at least two continuous radial slots (13) angularly spaced apart from each other and defining a detachable sheath portion (20a) which, when separated from the cable, defines, in the outer sheath (20), a window (J) for access to the core (10), each radial slot (13) having a trapezoidal shape, open and widened to the circular outer contour of the outer sheath (20), each radial slot (13) having a bottom that remains separated from the cavity (21), housing the core (10), by a breakable circumferential arc-shaped bridge (14).

2. Cable, according to claim 1, characterized in that it further comprises at least two tensile elements (30), metallic or dielectric, arranged longitudinally embedded in the outer sheath (20), in opposite positions and coplanar with the geometric axis of the cable, each tensile element (30) being embedded in a respective detachable sheath portion (20a).

3. Cable, according to claim 1, characterized in that the minimum radial thickness "A" of each bridge (14) and the circumferential extension "B" at the bottom of each groove (13) have, individually, a nominal value of 0.4 mm, with a tolerance of ± 0.3 mm.

4. Cable, according to claim 1, characterized in that each groove (13) has opposite sides of its trapezoidal shape forming an angle of 20° to 70°.

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