MXPA06014613A - Double shielded cable against humidity to be aerially or underground installed, including fiber optic for providing voice, video and data services - Google Patents

Abstract

Described is a double shielded cable against humidity to be aerially or underground installed, including fiber optic for providing voice, video and data services, which is based in a thermoplastic external cover with additives that is ultraviolet beam-resistant, the cable being characterised in that it comprises an optic core based on a slacked tube as a first protection against compression and impacts, a second protection against mechanical stress originated by compressing being located in the fastening and tension points using four dielectric mechanisms, the invention further comprising a double shield against humidity.

Description

CABLE OF DOUBLE PROTECTION AGAINST MOISTURE FOR AERIAL OR SOUND INSTALLATION WITH OPTICAL FIBERS TO PROVIDE SERVICES VOICE VIDEO AND DATA BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a cable for aerial or underground installation for the transmission of information by means of optical fibers that allows to provide high speed communications services including voice, video and data transport from the public telephony network to the point of connection to the end user, increasing the transmission capacity, with respect to a conventional connection cable whose transport medium is based on copper conductors, this new design comprising an information transport capacity up to 10 GHz in distances of up to 500 m. This is achieved through the inclusion of communication-grade optical fibers, which are the core of this binding medium, which is supported by reinforcement elements that can be metallic, aramid fibers, or glass fibers, which provide it to the cable the self-supporting feature when installed in aerial form. The structure of the cable consists of three fundamental elements: A central element or core that contains the optical fibers protected against moisture, protection that is achieved based on gel or absorbing threads or powders that prevent their penetration, whether this moisture comes from rain when installed in air or flood when it is installed in underground form.

An external cover whose design minimizes the compressive stresses on the central core that contains the optical fibers, which could be transmitted as a consequence of the use of the available hardware for its support, in the cable attachment points. Reinforcement elements that can be metallic, based on aramid fibers or fiberglass that give the cable the self-sustaining characteristic.

Description of the Prior Art The connection to the telephony network is normally made with cables that include copper elements which present some limitations or disadvantages with respect to the proposed cable improvements such as: High transmission speed and total noise elimination electromagnetic induction since the optical fiber is totally immune to these effects.

Different designs of cables with copper elements have been offered to improve their information transport capacity until they reach the intrinsic limitation of their materials; In general, copper cable connection designs have limitations in terms of transmission speed and designs based on coaxial cables have disadvantages in terms of signal quality due to the problem of susceptibility to electromagnetic induction, as is the case with following developments: In the patent US 6064,008 describes a communication cable that has two pairs of electrical conductors braided and isolated with fluorinated polymer. In US Pat. No. 5,180,890 a rectangular-type cable with two tension members is indicated, one arranged at each end and two copper conductors separated from each other and aligned horizontally in parallel.

The one described by US Pat. No. 4,467,138 which describes "a plural communication conductor cable" that uses two or more pairs of wires isolated with polyolefin material twisted over the entire length of the cable, grouped together by these twisted pairs and arranged in parallel with a wire of conductive steel New connections to the telephone network include cables whose design includes optical fibers to counteract the limitations and / or advantages mentioned above; however, its design and construction is made for very particular conditions of operation, such is the case of the following: Patent US2004022505 describes a connection cable with optical fibers to carry the signal from the area of the sidewalk to the interior of buildings. The design structure uses reinforcements in the form of lateral slats secured to each other and wrapping the central core consisting of a group of optical fibers arranged in the center of the cable. In this patent, the manufacturing method and a protection system known as the cushioned type for optical fibers are described, however, in this patent the cable fixing hardware required during its installation and operation is not established, these hardware would not be standard, they should be To be very specialized to avoid during its application to damage the center of the cable that is where the optical fibers are, assuring its fixation only of the end battens.

The patent US2003012529 describes a connection cable whose design comprises of an asymmetric assembly with an element with optical fibers in the center of the main body of the cable, two dielectric reinforcements lateral to the fibers and another portion with a third additional reinforcement. This type of cable entails difficulties in the cable manufacturing process as it does not have a symmetrical cross section, requiring the provision of reinforcements in specific places and using a plurality of support materials; Like, during the installation and operation process, since its fixation and splicing must be done in a very complicated way, with special accessories and specific for this design. Even in the cited document itself, the authors describe the problems for handling and arranging the fibers in the junction boxes.

The patent US6493491 also describes a drop cable with at least one optical fiber in the center of the cable and a pair of reinforcing members of a high modulus material such as polybenzoxazole. In this case the optical core is protected in the central part of the cable by a depression in the cover but the reinforcement elements are larger than the central cavity where the fibers are and the reinforcement material indicated is of special dimensions. such that it affects the cost of the cable. Another differential aspect with respect to the design of this document is the inclusion of a cavity to loosely accommodate the fibers instead of a tube. This is handled as an advantage in the aforementioned document, rather it consists of an aspect of complication of the design, since its manufacture requires sophisticated tooling to be able to apply the external cover and to maintain the slack inside the cavity without it being collapse and affect the performance of optical fibers, becoming a highly vulnerable point and difficult to control during the manufacturing process.

The patent US4892382 (1990) integrates a dielectric connection cable with flame-resistant optical fibers according to the VW-1 standard, the design consists of a central tube for housing the optical fibers flooded with a grease, a mechanical protection formed by two layers, a first layer of fiberglass-based material completely surrounding the central tube and a second layer of fiberglass elements impregnated with a resin surrounding the first, a second tube which is of flame retardant material surrounding the second layer. This cable is classified within the family of cables for connection, however, neither by the design nor by the document, it is mentioned that it can be installed in aerial form, nor does it speak of the fastening method for its installation if that were the case , so it is considered that the product only covers one aspect of use and not the complete solution of the application.

The patent JP2002341203 describes a connection cable with optical fibers to reach the house, composed of a central tube that includes the optical fibers and two lateral tension elements. The conformation of the cable is circular so it constitutes a different construction.

Patent JP2004093694 and JP2004101625 also describe connection cables including optical fibers inside a central optical unit and tension elements applied laterally with respect to the central tube that support the cable.

In the patent JP2004101624 a connection cable similar to those described in JP2004093694 and JP2004101625 is mentioned, with the variant which in this case is a core comprising a plurality of ribbon-shaped optical fibers and the cross section of the cable It is rectangular.

Patent JP2003232971 discloses an aerial connection cable with a support part separated from the optical part and two reinforcements applied laterally of the optical fibers. Three supporting elements are required that do not distribute forces symmetrically in the body of the cable. It is a figure 8 type cable that differs from the one proposed in this document in the way that it can be handled in the fastening points when it comes to aerial installations.

The patent JP2002341203 describes a connection cable with optical fibers for deriving optical fibers from trunk cables installed in drainage ducts. The application of this cable is specific for aggressive environments not for aerial installation and the distribution of the reinforcements is lateral to the optical fibers.

The patent WO0133276 (also published as US6256438) describes another connection cable with a reinforcement layer inside which are optical fibers protected against humidity and on the outside a protective cover. This design, although cataloged as a service cable, its use is limited to installations that are not carried out in aerial form since it does not contain elements that support its weight. Additionally, the use of a metallic reinforcement to contain the optical fibers must contain an internal moisture blocking layer which, due to the function it performs, constitutes an element that contributes significantly to the total weight of the cable.

In summary, from the reviewed documents of the prior art it is concluded that the proposed cable design differs from those described in the following points: • The application of the present invention is for both aerial and underground installations or in duct.

• The structure includes four reinforcing dielectric elements, distributing in a homogeneous way the tension generated by the weight of the cable when it is installed in aerial form.

• The fibers lodge loosely, protected for cases of expansion or contraction of the cable due to extreme climatic conditions or by longitudinal tension applied on the cable, either during its installation or during the operation thereof.

• The protection of the optical fibers of the central element is loose type, includes optical fibers that are protected by elements that can be dry (threads or dust blocking the entry of moisture) or based on a fat or hydrophobic gel to prevent transmission of water along the optical unit.

• The shape of the cable and the dimensions of the outer casing defined can be the same of cable with standard copper pairs for which standard fastening hardware can be used, so it does not require special fittings or different fastening mechanisms for cables. rush.

DESCRIPTION OF THE INVENTION The invention is described below according to the drawings of figures 1 and 2 Fig. 1. Corresponds to a cross-section upper sectional view (A, B) of the connection cable with double protection against air or underground humidity with optical fiber core for video and data voice.

Fig. 2 Corresponds to a cross-sectional perspective view showing the construction of the cable of fig. 1 The invention comprises a connection cable Fig. 1 and 2, for aerial installation, in duct or underground that allows the transmission of voice, video and data at high speeds that exceeds the increasing demand for information transport capacity by users final.

The drop cable of the present invention 10, comprises a design that can be applicable to connection cables of conventional copper pairs and preferably to optical fiber cores, which is the object of the invention, therefore the design is integrated by the following components: A section of cover 13, external thermoplastic with semi-rectangular geometry of polymeric material with additives that make it resistant to ultraviolet (UV) rays and resistant to the propagation of fire, said section of cover has four dielectric elements 16, located equidistantly each at one end of the cable geometry, respectively and in symmetry to provide self-supporting capability for aerial connections, characterized by including at the center of the covered section 13 of the cable an optical core 12 of polymeric material as the first protection in the form of loose tube, in which the optical fibers 11 are loosely accommodated which can be one or even spans at the same time, (singlemode or multimode) said fibers are also protected in turn from the compression and impact efforts (second protection) by the contour of the outer cover 13. The optical core 12 is protected against mechanical stresses by compression at the fastening points, and tension to include reinforcement elements 16 that provide self-support of the cable 10, said reinforcements are elements based on aramid, fiber of Glass or material based on carbon fiber. Also, because the application of the cable object of the invention can be aerial and in spaces outside buildings, it includes a double protection against the penetration of moisture where said protection can be: First as a super absorbent inflatable powder layer 17, which is applied uniformly by electrostatic means or other methods on the surface of the loose tube, said powder is a product based on sodium polyacrylate.

Second, there is provided a blocking against moisture that prevents the penetration of this along the loose tube, said blocking can be done inside the tube either by introducing a hydrocarbon-based gel 15 and with hydrophobic characteristic, or by the inclusion of moisture absorbing threads 14 within the cavity of the loose tube 12.

Advantages of the Invention: The following advantages of the present invention are detailed with respect to the prior art analyzed: Due to the structure of the reinforcement components and the dimensional configuration of the cover, this cable allows the connection of optical fibers to the home in different ways including: Outdoor aerial installation. Because the cover is resistant to UV rays and weathering; the four reinforcements adequately support the weight of the cable for connections up to 60m.

Underground installation. For the design of the specific contour of the roof over the core and for its resistance to deformation that allow it to reach a minimum compressive strength of 440 N / cm., (Characteristics achieved by the rigidity of the material and by the inclusion of the four dielectric reinforcement elements embedded in the cover).

Interior installation Due to its flame retardant characteristic, this cable can also be installed in the interior of buildings between different levels (Riser grade) or stairs of common electrical installations in buildings.

| Installation in doubt. This cable, having no metallic elements and due to its reduced dimensions, is very light, a feature that allows it to be installed in small diameter pipelines, by pulling or by the blowing technique.

• The fastening at the ends is very simple, being made with fittings available in the market are handled in a common way in the installation operations.

The use of dielectric materials in the conformation of the cable gives it a flexibility that facilitates its manipulation so that both the installation and the connectorization in the junction boxes are made in a faster and more reliable way.

• The inclusion of a loose tube in the center of the cable for secondary protection of the optical fibers allows the manipulation with a standard tool to remove the outer cover quickly and reliably, minimizing the risk of damage to the optical fibers during the preparation maneuver from the ends at the connection points.

The characteristics of the cable object of the invention are described below in Table 1: TABLE 1 The dimensions of the cable in its sections A and B are indicated below: Section B of the cable of fig. 1 is approximately 6 mm Section A of the cable of FIG. 1 is approximately 4.2 mm The outer diameter of the loose tube 12 is 2 mm.

The water blocking (Binder) is a ribbon which is impregnated with moisture absorbing dust. It reapplies in the wiring of the buffer tubes and has double function; The first consists of not allowing the passage of water through the cable, swelling the flat wire (Binder) when in contact with it, in such a way that it blocks and stops the passage of water in an optical cable. The second function is to hold the buffer tubes after they have been wired around the dielectric (pultruded) central reinforcement.

-The binder flat wire should be able to withstand the process speeds in the wiring up to 4000 rpm, ensuring that there are no breaks when working at these speeds.

-The material must comply with the characteristics of the table (2) as shown below: TABLE 2 Having described the invention this is considered a novelty and therefore the content of the following claims is claimed:

Claims (1)

1. R E I V I N D I C A C I O N S Cable with double protection against humidity for aerial or underground installation with optical fibers to provide voice, video and data services which comprises a thermoplastic external cover section with additives resistant to ultraviolet rays of semirectangular geometry, where said section has four dielectric elements located equidistantly each respectively at a corner end of the cover section, characterized by including at the center of the cover section an optical core, wherein said core is composed of a loose tube of polymeric material as the first protection of the optical fibers against the compression and impact forces, being housed in said tube one or several pairs of optical fibers simultaneously transporting optical signals in monomodal or multimodal form, likewise with a second protection to said fibers the core is protected against mechanical efforts by compression in the clamping and tension points by means of the inclusion of the four dielectric elements that act as reinforcements that provide the self-support of the cable, when said cable is aerial also comprises double protection against the penetration of moisture by means of a first layer of inflatable dust disposed around the cable. the outer periphery of the loose tube, and a second layer inside the loose tube of gel filling, said cable being very light due to the lack of metallic elements and does not require special fittings for its installation. The cable with double protection against humidity for aerial installation or buried with optical fibers of clause 1, characterized in that the outer cover section of polymeric material contains additives that make resistant to ultraviolet rays and resistant to the propagation of fire. The cable with double protection against humidity for aerial installation or buried with optical fibers of clause 1, characterized in that the cover has four reinforcing dielectric elements arranged in symmetry to provide self-supporting capacity for air connections of up to 60 meters of extension where said reinforcing elements are fibers based on aramid fiberglass or material based on carbon fibers and when the connection is buried due to its resistance to deformation allow it to achieve a minimum compressive strength of 440 N / cm. The cable with double protection against humidity for aerial installation or buried with optical fibers of clause 1, characterized in that the inflatable powder layer is super absorbent material and is applied uniformly or by electrostatic means and said product is a polyacrylate compound of sodium. The cable with double protection against humidity for aerial installation or buried with optical fibers of clause 1, characterized in that the blocking material inside the loose tube that avoids the total humidity is a hydrocarbon-based filling gel and hydrophobic characteristic. The cable with double protection against moisture for aerial installation or buried with optical fibers of clause 5, characterized in that the inner lock of the loose tube can also be by the inclusion of moisture absorbing threads, where said thread is an impregnated tape of moisture absorbing powder whose main function is to block the passage of moisture in the cable by swelling in contact with water, as well as to hold the buffer tubes after they have been wired around the central dielectric reinforcement. The cable with double protection against humidity for aerial installation or buried with optical fibers of clause 6, characterized in that said wire shall be able to withstand the process speeds in the wiring up to 4000 rpm.