KR100465116B1 - Metallic optical cable having circular structure using tight buffered optical fiber unit - Google Patents

Abstract

Disclosed is a circular metal structured optical cable in which a tight buffer optical fiber unit is twisted together with a metallic tensile wire and assembled on an outer periphery of the tensile tension wire. This circular structured metal optical cable includes: a tensile tension line made of metal extending in the longitudinal direction from the center of the optical cable; A tight buffer fiber optic unit and metallic tensile wire, which are twisted in the longitudinal direction substantially enclosing the outer circumference of the tensile tension line and together with the tensile tension line form a cable core assembly; And a cable sheath made of a plastic resin surrounding the outer circumference of the cable core assembly.

Such a metal optical cable can reduce the outer diameter of the cable while satisfying the tensile strength condition of the optical cable, and is particularly advantageous when the optical cable is processed and laid in a self-supporting type. This can reduce the time and cost of the optical cable manufacturing process.

Description

METALLIC OPTICAL CABLE HAVING CIRCULAR STRUCTURE USING TIGHT BUFFERED OPTICAL FIBER UNIT}

The present invention relates to a metallic optical cable, and more particularly, to a metallic optical cable having a circular structure in which a tight buffer optical fiber unit is twisted together with a metallic tensile wire and assembled on an outer periphery of the tensile tension wire.

Optical cables, also called fiber optic cables, are commonly used to convert electrical signals into light signals and pass them through optical fibers. Optical cables are classified in various ways according to their structure and environment. In particular, optical cables installed in the air are called overhead cables or overhead cables.

The overhead cable may be installed to hang using a hanger on a pre-installed support line, but in recent years, a cable and a support line are often integrated and manufactured, which is called a self supporting cable (SS cable). Call. In addition, the self-supporting cable is configured to connect the outer sheath of the cable and the outer sheath of the support line through the narrowed portion, and sometimes the above-described cable sheath and the supporting sheath sheath surrounds the lashing wire.

First, Figure 1 shows an example of a self-supporting optical cable according to the prior art. The optical cable shown in FIG. 1 applies a tight buffer optical fiber unit as described later.

Referring to FIG. 1, a conventional optical cable has a tensile tension line 41 at a center position, and the tensile tension line 41 extends in the longitudinal direction from the center of the cable. A plurality of optical fiber units 50 are disposed on the outer circumferential surface of the tensile tension line 41. The optical fiber unit 50 includes an optical fiber 42, a tight buffer 43, a tension member 44, and a sheath 45. This optical fiber unit 50 is hereinafter referred to as a tight buffer optical fiber unit. In the above-described tight buffer optical fiber unit 50, the number of core wires of the optical fiber 42 is one or two, and each optical fiber 42 is surrounded by the tight buffer 43. Tensile member 44 is generally made of aramid yarn (Aramid yarn). The plurality of optical fiber units 42 are arranged to be twisted by helical or SZ on the outer circumferential surface of the tensile tension line 41. On the optical fiber unit 42, an external tension member 47 made of a non-metallic material is provided in a transverse winding or in a vertical shape. On the outer tension member 47, a cable jacket 48 made of a plastic resin such as polyvinylchloride or polyethylene is provided. A gap in the cable sheath 48 may be filled with a separate filler.

In the optical cable of FIG. 1, it is essential to have a strict tension member 47 around the optical fiber unit 50 to protect the tight buffer type optical fiber unit 50. Therefore, the above-described optical cable has problems such as an increase in the outer diameter of the optical cable and an increase in the manufacturing process according to the use of the external tension member 47, and thus increase the manufacturing cost.

The self-supporting optical cable shown in FIG. 2 uses a tight buffer optical fiber unit 50 similar to that of FIG. 1, except that a separate support line is connected to the cable. That is, the support line in which a plurality of tension lines 48b twisted in the longitudinal direction are inserted into the outer shell 48a is coupled to the optical cable of FIG. 1.

As described above, the self-supporting optical cable of FIG. 2, in which the support line is connected to the cable, has the disadvantage of the optical cable of FIG. 1, and the overall configuration has an eight-character shape.

Therefore, the present invention was devised to solve the above problems, by using a central tensile tension wire as a metal material and replacing a part of the tight buffer optical fiber unit with a metallic tension wire material to use a separate external tension material or to integrate a support line. It is an object of the present invention to provide a metal optical cable having a circular structure capable of exerting sufficient tensile strength with a small outer diameter without being manufactured.

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to

1 is a cross-sectional view showing an example of a self-supporting optical cable in the form of a tight buffer according to the prior art.

2 is a cross-sectional view showing another example of a self-supporting optical cable in the form of a tight buffer according to the prior art;

3 is a cross-sectional view showing a metal optical cable according to the present invention.

<Explanation of symbols for the main parts of the drawings>

51..Tension tension wire 58 .. Cable sheath

60. Optical fiber unit 70. Metallic tensile wire

Metal-type optical cable according to the present invention for achieving the above object is a tensile tension line of a metal material extending in the longitudinal direction from the center of the optical cable; An optical fiber unit and a metallic tensile wire material including one or more tight buffer optical fibers, which are twisted in a length direction while substantially enclosing the outer circumference of the tensile tension wire, and together with the tensile tension wire, form a cable core assembly; And a cable sheath made of plastic resin surrounding the outer circumference of the cable core assembly.

Preferably, the cable core assembly further includes an inclusion.

Also preferably, the number of metallic tensile wires may be determined in consideration of the tensile force of the optical cable, and an inclusion made of plastic resin may be further disposed on an outer circumferential surface of the tensile wire in which the optical fiber unit and the metallic tensile wire are not disposed.

In this case, the number of the metallic tensile wire is preferably two or more.

In addition, it is preferable that the cable core assembly is substantially in contact with the inner surface of the cable sheath, and it is also preferable that the optical fiber unit and the metallic tensile wire have the same diameter.

In the above-described configuration, the metallic tensile wire is preferably having an outer diameter of 0.6 ~ 6.0 mm, the metallic tensile wire is any one selected from the group consisting of galvanized steel wire, copper wire, iron wire, steel wire and aluminum coated steel wire Is made of a combination of

In addition, the cable jacket preferably has a thickness of 0.6 ~ 1.5 mm, the cable jacket is polyvinyl chloride, halogen-free flame retardant thermoplastic, polyethylene (polyethylene) and polyurethane ( Polyurethane) is selected from the group consisting of.

Preferably, the gap in the cable sheath may include hygroscopic fillers or absorbent fibers.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

3 is a cross-sectional view showing the configuration of a metal optical cable according to the present invention.

Referring to Figure 3, the metal optical cable of the present invention has a tensile tension line 51 extending in the longitudinal direction of the optical cable in the center position. The tensile tension line 51 is made of a metal material, and minimizes the effect caused on the optical fiber mounted on the optical cable by the tensile stress caused during the drum winding or installation of the optical cable.

On the outer circumferential surface of the tensile tension line 51, an optical fiber unit 60 including one or more tight buffer optical fibers, which are twisted helically or SZ in the longitudinal direction and centered on the tensile tension line 51, is disposed. The optical fiber unit 60 is composed of an optical fiber 52, a tight buffering 53, a tension member 54 and a sheath 55. Although the number of core wires of the optical fiber 52 in the tight buffer optical fiber unit 60 is shown as one in the figure, two core wires may be used as necessary. When there are two core wires of the optical fiber 52 used, each optical fiber 52 is surrounded by a separate tight buffering 53. In addition, the optical fiber unit 60 may be used in place of an optical fiber unit including a ribbon of two or more ribbons. Tension member 54 is generally made of aramid yarn (Aramid yarn). This optical fiber unit 60 has an outer diameter of approximately 0.9 to 3.0 mm as a whole.

The optical cable according to the present invention has one or more optical fiber units 60. However, not all of the periphery of the tensile tension line 51 is surrounded by the optical fiber unit 60, and the tensile wire material 70 made of a metal material is disposed in place of the optical fiber unit 60 instead of the optical fiber unit 60. .

The metallic tensile wire 70 may be any one selected from the group consisting of galvanized steel wire, copper wire steel wire, iron wire, steel wire and aluminum coated steel wire, or a combination thereof. The metallic tensile wire 70 replaces a part of the optical fiber unit of the conventional self-supporting optical cable shown in FIGS. 1 and 2. Accordingly, the metallic tensile wire 70 used in the optical cable of the present invention maintains the cross section of the optical cable in a circular shape and protects the optical fiber unit by preventing deformation of the cable sheath from external impact, and exhibits a unique tensile force of the metal. This further enhances the tensile strength of the optical cable itself. Therefore, in the related art, an external tension member made of a non-metallic material is required to reinforce the tensile force of the optical cable. However, in the present invention, the metallic tension wire 70 replaces the role of the external tension member and thus does not require an external tension member.

Two or more metallic tensile wires 70 are preferably used. That is, at least two or more metallic tensile wires 70 are disposed on the outer circumferential surface of the tensile tension line 51 together with the one or more optical fiber units 60. The outer diameter of the metallic tensile wire 70 is determined in the range of 0.6 ~ 6.0 mm. If the outer diameter of the metallic tensile wire 70 is 0.6 mm or less, it is not possible to guarantee an appropriate level of tensile force, and if the outer diameter of 6.0 mm or more causes an increase in the outer diameter of the optical cable, reducing the cable outer diameter by introducing the metallic tensile wire 70. It is hard to expect.

Since the metallic tensile wire 70 is resistant to external impact or side pressure, it is very advantageous to protect the optical fiber unit 60 disposed at the periphery. In addition, since the metallic tensile wire 70 has a low thermal expansion rate of the metal material used and thus is hardly affected by external temperature change, the metallic tensile wire 70 is helpful in improving low / high temperature characteristics of the optical cable.

In addition, in the present invention, the tensile force of the optical cable itself may be adjusted by controlling the number of metallic tensile wires 70. That is, the number of metallic tensile wires 70 used is determined in consideration of the tensile force required for the optical cable. Of course, the number of uses of the metallic tensile wire 70 is limited by the number of optical fiber units 60 required. In the figure, as an example, two optical fiber units 60 and four metallic tensile wires 70 are disposed on the outer circumferential surface of the tensile tension line 51. In addition, a portion of the above-described metallic tension wire 70 may be replaced by the inclusions used in the prior art. The use of inclusions is useful to reduce unnecessary tension.

The optical fiber unit 60 and the metallic tensile wire 70 are arranged to form one circumference around the tensile tension line 51. For this purpose, it is preferable that the optical fiber unit 60 and the metallic tensile wire 70 have the same diameter. In addition, the optical fiber unit 60 and the metallic tensile wire 70 are gathered in the longitudinal direction at the outer circumference of the tensile tension line 51 to be twisted helical or SZ.

The tensile tension line 51, the optical fiber unit 60 and the metallic tension wire 70 collected therein constitute a cable core assembly. Of course, when the inclusions are further gathered on the outer periphery of the tensile tension line 51, the cable core assembly further includes the inclusions.

The cable core assembly is longitudinally wrapped by cable sheath 58. Accordingly, in the present invention, the optical fiber unit 60 and the metallic tensile wire 70 are in substantial contact with the inner surface of the cable sheath 58.

The cable sheath 58 is made of plastic resin, and preferred plastic resins that may be used include polyvinylchloride, halogen free flame retardant thermoplastic, polyethylene or polyurethane. It may be mentioned, but the present invention is not limited thereto.

The cable sheath 58 is formed by coating a plastic resin, and has a thickness of 0.1 to 3.0 mm. If the thickness of the outer shell 58 is 0.1 mm or less, there is a disadvantage in that the function of the outer shell is not properly exhibited and workability is reduced. In addition, when the thickness of the outer jacket 58 is 3.0 mm or more, the radius of curvature of the cable increases, which may cause problems in laying work.

Gaps in the cable sheath 58 may be filled with hygroscopic fillers or absorbent fibers to prevent moisture from penetrating into the optical cable. As the hygroscopic filler, jelly compound or silicone oil may be used, but the present invention is not limited thereto.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims to be described.

The metal optical cable according to the present invention does not require a conventional external tension material by the use of a metallic tension wire, and because it retains sufficient tensile strength by the metallic tension wire, it is not necessary to separately provide a support line like a conventional optical cable. Therefore, the optical cable of the present invention has a smaller cable outer diameter than the conventional optical cable, and is particularly advantageous when the optical cable is processed and laid in a self supporting type.

In addition, the optical cable of the present invention is simplified because the process of covering the external tension material is omitted, thereby making it possible to reduce the manufacturing cost.

Claims (11)

In the metal optical cable, Tensile tension lines made of metal extending in the longitudinal direction from the center of the optical cable; An optical fiber unit and a metallic tensile wire material including one or more tight buffer optical fibers, which are twisted in a length direction while substantially enclosing the outer circumference of the tensile tension wire, and together with the tensile tension wire, form a cable core assembly; And Metal-type optical cable comprising a cable shell made of a plastic resin surrounding the outer periphery of the cable core assembly. The method of claim 1, The cable core assembly further comprises an inclusion type metal optical cable. The method of claim 1, The number of metallic tensile wires is determined in consideration of the tensile force of the optical cable, The optical fiber unit and the metallic optical cable, characterized in that the inclusion portion made of a plastic resin is further disposed on the outer circumferential surface of the tensile wire is not disposed. The method of claim 1, Metal type optical cable, characterized in that the number of the metallic tensile wires two or more. The method according to any one of claims 1 to 4, And said cable core assembly is substantially in contact with an inner surface of said cable sheath. The method according to any one of claims 1 to 4, And the optical fiber unit and the metallic tensile wire have the same diameter. The method according to any one of claims 1 to 4, The metallic tensile wire is a metal optical cable, characterized in that having an outer diameter of 0.6 ~ 6.0 mm. The method according to any one of claims 1 to 4, The metallic tensile wire is any one or a combination thereof selected from the group consisting of galvanized steel wire, copper wire steel wire, iron wire, steel wire and aluminum coated steel wire. The method according to any one of claims 1 to 4, The cable sheath is a metal optical cable, characterized in that having a thickness of 0.1 ~ 3.0 mm. The method according to any one of claims 1 to 4, The outer sheath of the cable is made of polyvinylchloride, a halogen-free flame retardant thermoplastic, a metal optical cable, characterized in that made of any one selected from the group consisting of polyethylene, polyethylene, and polyurethane. . The method according to any one of claims 1 to 4, The gap in the cable jacket includes a hygroscopic filler or absorbent fiber.