Description:TECHNICAL FIELD
The present disclosure relates to the field of optical fiber cables and, in particular, relates to an optical fiber cable with metal armoring.

BACKGROUND
Optical fibers are widely used to transmit information or data in form of light from one place to another. The optical fibers are disposed within the optical fiber cable. The optical fiber cables are widely known in the prior art. Specifically, there are various optical fiber cables that are known in the prior art, which are provided with metal armours. The metallic armour layer in conventional optical fiber cables is supported or wrapped around a sheath or an inner tube, which encloses the optical fibers. In conventional fiber cable, putting a conventional metal armour tape directly over the fibers may collapse the circularity of the optical fiber cable, which causes increased attenuation and macro bending of the optical fiber cable. Further, having an inner sheath/tube below the metallic armour may increase the diameter and weight of the cable. For example, the reference CN209640553U discloses use of spiral armour around a ribbon stack. It has a TPE based hard pressed bale layer over stack to support the armour. Another reference CN210051943U discloses use of spiral armour around cable core with optical fiber ribbons. It has a PVC/TPU based protective inner layer around the ribbons and then a reinforcing layer of aramids to support the armour. Another reference CN203385911U discloses use of metal braid applied around an inner sheath enclosing optical fibers. Another reference CN217425788U discloses use of non-metallic (Aramid) braiding the core of optical fiber cable, including peelable microtubes with ribbons.
In light of the above stated discussion, there is a need for an optical fiber cable with an optimal placement of armor layer to overcome the above stated disadvantages of the conventional optical fiber cables.

SUMMARY
In an aspect of the present disclosure, an optical fiber cable is disclosed. The optical fiber cable includes a plurality of optical fibers, an armor layer, and a sheath. The armor layer surrounds the plurality of optical fibers such that an empty space is formed between the armor layer and the plurality of optical fibers. The empty space is free from any material having stiffness greater than 60 Newton per meter (N/m). The sheath surrounds the armor layer.

BRIEF DESCRIPTION OF DRAWINGS
Having thus described the disclosure in general terms, reference will now be made to the accompanying figures, wherein:
FIG. 1A illustrates a cross sectional view of an optical fiber cable.
FIG. 1B illustrates a side view of the optical fiber cable of FIG. 1A.
FIG. 2A illustrates a cross sectional view of another optical fiber cable.
FIG. 2B illustrates a perspective view of the optical fiber cable of FIG. 2A.
It should be noted that the accompanying figures are intended to present illustrations of exemplary embodiments of the present disclosure. These figures are not intended to limit the scope of the present disclosure. It should also be noted that accompanying figures are not necessarily drawn to scale.

DEFINITIONS
The term “optical fiber” as used herein refers to a light guide that provides high-speed data transmission. The optical fiber includes one or more glass core regions and a glass cladding region. The light moving through the glass core regions of the optical fiber relies upon the principle of total internal reflection, where the glass core regions have a higher refractive index (n1) than the refractive index (n2) of the glass cladding region of the optical fiber.
The term “optical fiber cable” as used herein refers to a cable that encloses a plurality of optical fibers.
The term “intermittently bonded ribbon (IBR)” as used herein refers to an optical fiber ribbon having a plurality of optical fibers such that the plurality of optical fibers is intermittently bonded to each other by a plurality of bonded portions that are placed along the length of the plurality of optical fibers. The plurality of bonded portions is separated by a plurality of unbonded portions.
The term “armor filling coefficient” as used herein refers to a ratio of cross-sectional area of the plurality of optical fibers to cross-sectional area of an armor layer with respect to an outer surface of the armor layer. In other words, the armor filling coefficient refers to a packing density of optical fibers inside the armor layer.

DETAILED DESCRIPTION
The detailed description of the appended drawings is intended as a description of the currently preferred aspects of the present disclosure, and is not intended to represent the only form in which the present disclosure may be practiced. It is to be understood that the same or equivalent functions may be accomplished by different aspects that are intended to be encompassed within the spirit and scope of the present disclosure.
Moreover, although the following description contains many specifics for the purposes of illustration, anyone skilled in the art will appreciate that many variations and/or alterations to said details are within the scope of the present technology. Similarly, although many of the features of the present technology are described in terms of each other, or in conjunction with each other, one skilled in the art will appreciate that many of these features can be provided independently of other features. Accordingly, this description of the present technology is set forth without any loss of generality to, and without imposing limitations upon, the present technology.
FIG. 1A illustrates a cross sectional view of an optical fiber cable 100. The optical fiber cable 100 may be installed through various aerial overhead poles or laid inside various ducts that may be used in different applications.
The optical fiber cable 100 may have a plurality of optical fibers 102a -102n (hereinafter collectively referred to and designated as “the optical fibers 102”), an armor layer 104, one or more deformable layers 106a-106n (hereinafter collectively referred to and designated as “the deformable layers 106”), one or more layers 108a-108n (hereinafter collectively referred to and designated as “the layers 108”), and a sheath 110.
The optical fibers 102 may be disposed within the optical fiber cable 100.
In some aspects of the present disclosure, the optical fibers 102 may be in the form of one of, but not limited to, loose fibers, stacks of ribbons, bundles of ribbons, and intermittently bonded ribbon (IBR) bundles. Aspects of the present disclosure are intended to include and/or otherwise cover the optical fibers 102 in any form, without deviating from the scope of the present disclosure.
In some aspects of the present disclosure, the optical fibers 102 may be in form of a plurality of ribbons 112a-112n (hereinafter collectively referred to and designated as “the ribbons 112”).
In some aspects of the present disclosure, each ribbon of the ribbons 112 may be an intermittently bonded ribbon (IBR). The IBR may have a set of optical fibers of the optical fibers 102 such that the set of optical fibers are disposed parallel to each other. The set of optical fibers of the optical fibers 102 may be intermittently bonded by a plurality of bonded portions that may be separated by a plurality of unbonded portions.
In some aspects of the present disclosure, each optical fiber of the optical fibers 102 may be one of, a single mode fiber, a multi-mode fiber, a single core fiber, and a multi-core fiber.
The armor layer 104 may be adapted to surround the optical fibers 102 such that an empty space 114 is formed between the armor layer 104 and the optical fibers 102. The empty space 114 may be free from any material having stiffness greater than 60 Newton per meter (N/m).
In some aspects of the present disclosure, the armor layer 104 may be made up of a material including, but not limited to, steel and electrolytic chrome-coated steel (ECCS). Aspects of the present disclosure are intended to include and/or otherwise cover any type of known and later developed material for the armor layer 104.
In some aspects of the present disclosure, the armor layer 104 may have an armor filling coefficient that may be greater than 0.3. The armor filling coefficient being less than 0.3, may increase a diameter of the armor layer 104, which may eventually increase a diameter of the optical fiber cable 100.
In some aspects of the present disclosure, the empty space 114 may be at least partially filled with the deformable layers 106. Each layer of the deformable layers 106 may have a stiffness that may be less than or equal to 60 N/m. The optical fiber cable 100 advantageously avoids usage of any hard material to be disposed in between the optical fibers 102 and the armor layer 104. Specifically, the optical fiber cable 100 advantageously avoids usage of any layer having a stiffness greater than 60 N/m, as the material with stiffness greater than 60 N/m may create more empty space in a core of the optical fiber cable 100, which may increase the diameter of the optical fiber cable 100.
In some aspects of the present disclosure, one or more layers of the deformable layers 106 may be one of, a water blocking tape, a water swellable yarn, an aramid yarn, a mica tape, and a glass roving yarn. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the deformable layers 106, without deviating from the scope of the present disclosure.
In some aspects of the present disclosure, each layer of the deformable layers 106 may be deformable by a force (i.e., deformable force) of less than 0.5 N. The deformable force being greater than 0.5 N may categorize each layer of the deformable layers 106 in a hard material category.
The sheath 110 may surround the armor layer 104.In some aspects of the present disclosure, material of the sheath 110 may be one of, polyethylene, low-smoke zero-halogen (LSZH), polyvinyl chloride (PVC), thermoplastic polyurethane (TPU), and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of known and later developed materials, without deviating from the scope of the present disclosure.
In some aspects of the present disclosure, the layers 108 may be disposed between the armor layer 104 and the sheath 110.
In some aspects of the present disclosure, each layer of the layers 108 may be one of, but not limited to, a water blocking tape, a water swellable yarn, an aramid yarn, a mica tape, and a glass roving yarn. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the layers 108, without deviating from the scope of the present disclosure.
FIG. 1B illustrates a side view of the optical fiber cable 100 of FIG. 1A. As discussed, the optical fiber cable 100 may have the optical fibers 102, the armor layer 104, and the sheath 110. As illustrated in FIG. 1B, the armor layer 104 may be in the form of a spring and/or a spiral shaped metal layer. Specifically, the spiral shaped metal layer may enable maintaining a circular shape without need of any inner tube or sheath layer underneath the armor layer 104. Thus, the spiral shaped metal layer may eliminate the inner tube or the sheath, which may advantageously reduce a diameter of the optical fiber cable 100.
FIG. 2A illustrates a cross sectional view of another optical fiber cable 200. The optical fiber cable 200 may be substantially similar to the optical fiber cable 100, in terms of structural and functional aspects and the like elements of the optical fiber cable 100 are referenced with like numerals in the optical fiber cable 200. However, the optical fiber cable 200 is provided with the deformable layers 106 such that one or more deformable layers of the deformable layers 106 may be, but not limited to, a mica tape, a water blocking tape, a fire retardant tape, water swellable yarns, and the like. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the deformable layers 106 that has one or more properties similar to one of, a mica tape, a water blocking tape, a fire retardant tape, water swellable yarns, without deviating from the scope of the present disclosure. Further, in the optical fiber cable 200, the armor layer 104 may be the braided layer that may be formed by a plurality of metal wires.
In some aspects of the present disclosure, the layers 108 may be disposed between the armor layer 104 and the sheath 110 of optical fiber cable 200.
In some aspects of the present disclosure, each layer of the layers 108 may be one of, but not limited to, a water blocking tape, a water swellable yarn, an aramid yarn, a mica tape, and a glass roving yarn. Aspects of the present disclosure are intended to include and/or otherwise cover any type of the layers 108, without deviating from the scope of the present disclosure.
FIG. 2B illustrates a perspective view of the optical fiber cable 200. For sake of illustrative purposes, FIG. 2B shows only one deformable layer 106a (i.e., the mica tape) of the deformable layers 106 and only one ribbon 112a of the ribbons 112. Specifically, the ribbon 112a may be surrounded by the deformable layer 106a. The deformable layer 106a may be surrounded by the armor layer 104 (i.e., the braided layer formed by a plurality of metal wires). The armor layer 104 may be surrounded by the sheath 110. The armor layer 104 (i.e., the braided layer formed by a plurality of metal wires) may enable maintaining a circular shape without need of any inner tube or sheath layer underneath the armor layer 104.
Thus, the optical fiber cables 100 and 200 may advantageously have a reduced diameter. Since, the inner sheath or tube that may be disposed underneath the armor layer 106 is eliminated, therefore, the diameter of the optical fiber cables 100 and 200 is reduced. Further, the optical fiber cables 100 and 200 may require lesser number of layers, which again reduces the diameter of the optical fiber cables 100 and 200. The empty space 114 may be free from any solid or hard material, which may reduce weight of the optical fiber cables 100 and 200.
The foregoing descriptions of specific embodiments of the present technology have been presented for purpose of illustration and description. They are not intended to be exhaustive or to limit the present technology to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present technology and its practical application, to thereby enable others skilled in the art to best utilize the present technology and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present technology.
While several possible embodiments of the invention have been described above and illustrated in some cases, it should be interpreted and understood as to have been presented only by way of illustration and example, but not by limitation. Thus, the breadth and scope of a preferred embodiment should not be limited by any of the above-described exemplary embodiments.
, Claims:We Claim(s):
1. An optical fiber cable (100) comprising:
a plurality of optical fibers (102a-102n);
an armor layer (104) that surrounds the plurality of optical fibers (102a-102n) such that an empty space (114) is formed between the armor layer (104) and the plurality of optical fibers (102a-102n), where the empty space (114) is free from any material having stiffness greater than 60 Newton per meter (N/m); and
a sheath (110) that surrounds the armor layer (104).

2. The optical fiber cable (100) of claim 1, where the armor layer (104) is made up of one of, steel and electrolytic chrome-coated steel (ECCS).

3. The optical fiber cable (100) of claim 1, where the armor layer (104) is in form of one of, a spring shaped metal layer and braided layer that is formed by a plurality of metal wires.

4. The optical fiber cable (100) of claim 1, where the plurality of optical fibers (102a-102n) is in form of a plurality of ribbons (112a-112n).

5. The optical fiber cable (100) of claim 4, where each ribbon of the plurality of ribbons (112a-112n) is an intermittently bonded ribbon (IBR).

6. The optical fiber cable (100) of claim 1, further comprising one or more deformable layers (106a-106n) such that the empty space (114) is partially filled with the one or more deformable layers (106a-106n) where each deformable layer of the one of more deformable layers (106a-106n) has a stiffness that is less than or equal to 60 N/m.

7. The optical fiber cable (100) of claim 6, where each deformable layer of the one or more deformable layers (106a-106n) is one of, a water blocking tape, a water swellable yarn, an aramid yarn, a mica tape, a glass roving yarn.

8. The optical fiber cable (100) of claim 6, where each deformable layer of the one or more deformable layers (106a-106n) is deformable by a force of less than 0.5 N.

9. The optical fiber cable (100) of claim 1, where the armor layer (104) has an armor filling coefficient that is greater than 0.3.

10. The optical fiber cable (100) of claim 1, further comprising one or more layers (108a-108n) disposed between the armor layer (104) and the sheath (110).

11. The optical fiber cable (100) of claim 10, where each layer of the one or more layers (108a-108n) is one of, a water blocking tape, a water swellable yarn, an aramid yarn, a mica tape, a glass roving yarn.