Claims:Claims
What is claimed is:

1. An optical fiber cable (100) comprising:

a plurality of tight buffered fibers lying substantially along a longitudinal axis of the optical fiber cable (100), wherein each of the plurality of tight buffered fibers has a tight buffer coating of nylon;

a first layer (106) surrounding the plurality of tight buffered fibers, wherein the first layer (106) comprises one or more yarns, wherein the one or more yarns is an aramid yarn and wherein the first layer (106) acts as a strengthening member for the plurality of tight buffered fibers; and

a second layer (108) surrounding the first layer, wherein the second layer (108) is a low smoke zero halogen layer,

wherein the optical fiber cable (100) has a cable diameter of about 3.7 millimeters and wherein the optical fiber cable (100) has an aerial span length in a range of 30 meters to 35 meters.

2. The optical fiber cable (100) as recited in claim 1, further comprising a plurality of water swellable yarns extending along the longitudinal axis of the optical fiber cable, wherein the plurality of water swellable yarns prevent ingression of water inside a core of the optical fiber cable.

3. The optical fiber cable (100) as recited in claim 1, further comprising a plurality of ripcords placed inside the core and extending along the longitudinal axis of the optical fiber cable, wherein the plurality of ripcords facilitates access to the plurality of tight buffered fibers.

4. The optical fiber cable (100) as recited in claim 1, wherein the second layer (108) is ultraviolet proof and provides protection to the optical fiber cable (100).

5. The optical fiber cable (100) as recited in claim 1, wherein the one or more yarns provide tensile strength to the optical fiber cable (100) and wherein the tensile strength of the optical fiber cable is about 500 Newton.

6. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable has a crush resistance of about 500 Newton.

7. The optical fiber cable as recited in claim 1, wherein each of the plurality of tight buffered fibers has an inner diameter of about 0.25 millimeter and an outer diameter of about 0.60 millimeter.

8. The optical fiber cable as recited in claim 1, wherein the second layer (108) is an outer jacket of the optical fiber cable (100).

9. The optical fiber cable (100) as recited in claim 1, wherein the first layer (106) has a thickness of about 0.40 millimeter.

10. The optical fiber cable (100) as recited in claim 1, wherein the second layer (108) has a thickness of about 0.85 millimeter.

11. The optical fiber cable (100) as recited in claim 1, wherein the optical fiber cable (100) is compatible with Field mountable connectors (FMC).
Dated: 28th Day of March, 2016 Signature
Arun Kishore Narasani Patent Agent

, Description:TECHNICAL FIELD
[0001] The present disclosure relates to the field of optical fiber cable and, in particular, relates to an optical fiber drop cable for indoor - outdoor installation.

BACKGROUND
[0002] Over the last few years, there has been a rapid growth in the use of optical fiber cables for numerous applications. One such type of optical fiber cable is fiber optic drop cables used for broadband applications, communication applications and the like. These fiber optic drop cables are utilized for aerial installations, underground installations, direct burial installation, indoor installation and the like. The fiber optic drop cables have a small diameter which makes these cables suitable for drop installations. Traditionally, the structure of these fiber optic drop cables includes one or more tight buffered fibers. In general, no gel is present in the tight buffered fibers. Conventionally, these tight buffered fibers are coated. In addition, the one or more tight buffered fibers are surrounded by binding heads (or yarn layer) and an outer sheathing layer. The outer sheathing layer protects the drop cable from harsh environment conditions.

[0003] The conventional structures of the fiber optic drop cables have certain drawbacks. The conventional fiber optic drop cables have a large tight buffer coating. The large tight buffer coating increases the diameter of the optical fiber cable. This makes the fiber optic cable unsuitable for installation. In addition, the packing density of the optical fibers in the fiber optic drop cables is low. Moreover, the conventional fiber optic drop cables have a small aerial span length. The conventional fiber optic cables are not compatible with standard Field Mountable Connectors (FMC). These fiber optic cables do not fit properly inside these connectors due to the diameter of these cables being too small or too large. Further, the conventional fiber optic drop cables do not provide optimal protection against signal attenuation. Furthermore, the minimum bending radius of the conventional fiber optic drop cables is high. Also, the installation of the conventional fiber optic drop cables is not economical.

[0004] In light of the foregoing discussion, there exists a need for an optical fiber cable which overcomes the above cited drawbacks of conventionally known optical fiber cables.

OBJECT OF THE DISCLOSURE
[0005] A primary object of the disclosure is to provide an optical fiber cable for an ease in installation for indoor - outdoor applications.

[0006] Another object of the present disclosure is to provide the optical fiber cable having a small diameter.

[0007] Yet another object of the present disclosure is to provide the optical fiber cable with a large aerial span length.

[0008] Yet another object of the present disclosure is to provide the optical fiber cable having low signal attenuation.

[0009] Yet another object of the present disclosure is to provide bend insensitive optical fiber cable.

[0010] Yet another object of the present disclosure is to provide the optical fiber cable compatible with Field Programmable Mezzanine Card (FMC) connectors.

SUMMARY
[0011] In an aspect, the present disclosure provides an optical fiber cable. The optical fiber cable includes a plurality of tight buffered fibers. The plurality of tight buffered fibers lies substantially along a longitudinal axis of the optical fiber cable. In addition, the optical fiber cable includes a first layer. The first layer surrounds the plurality of tight buffered fibers. Moreover, the optical fiber cable includes a second layer. The second layer surrounds the first layer. Further, each of the plurality of tight buffered fibers has a tight buffer coating of nylon. In addition, the first layer includes one or more yarns. The one or more yarns are an aramid yarn. Moreover, the first layer acts as a strengthening member for the plurality of tight buffered fibers. The second layer is a low smoke zero halogen layer. Further, the optical fiber cable has a cable diameter of about 3.7 millimeters. Furthermore, the optical fiber cable has an aerial span length in a range of 30 meters to 35 meters.

[0012] In an embodiment of the present disclosure, the optical fiber cable further includes a plurality of water swellable yarns. The plurality of water swellable yarns extends along the longitudinal axis of the optical fiber cable. The plurality of water swellable yarns prevents ingression of water inside a core of the optical fiber cable.

[0013] In an embodiment of the present disclosure, the optical fiber cable further includes a plurality of ripcords. The plurality of ripcords is placed inside the core and extends along the longitudinal axis of the optical fiber cable. The plurality of ripcords facilitates access to the plurality of tight buffered fibers.

[0014] In an embodiment of the present disclosure, the second layer is ultraviolet proof and provides protection to the optical fiber cable.

[0015] In an embodiment of the present disclosure, the one or more yarns provide tensile strength to the optical fiber cable. The tensile strength of the optical fiber cable is about 500 Newton.

[0016] In an embodiment of the present disclosure, the optical fiber cable has a crush resistance of about 500 Newton.

[0017] In an embodiment of the present disclosure, each of the plurality of tight buffered fibers has an inner diameter of about 0.25 millimeter and an outer diameter of about 0.60 millimeter.

[0018] In an embodiment of the present disclosure, the second layer is an outer jacket of the optical fiber cable.

[0019] In an embodiment of the present disclosure, the first layer has a thickness of about 0.40 millimeter.

[0020] In an embodiment of the present disclosure, the second layer has a thickness of about 0.85 millimeter.

[0021] In an embodiment of the present disclosure, the optical fiber cable is compatible with Field mountable connectors (FMC).

STATEMENT OF THE DISCLOSURE
[0022] The present disclosure relates to an optical fiber cable. The optical fiber cable includes a plurality of tight buffered fibers. The plurality of tight buffered fibers lies substantially along a longitudinal axis of the optical fiber cable. In addition, the optical fiber cable includes a first layer. The first layer surrounds the plurality of tight buffered fibers. Moreover, the optical fiber cable includes a second layer. The second layer surrounds the first layer. Further, each of the plurality of tight buffered fibers has a tight buffer coating of nylon. In addition, the first layer includes one or more yarns. The one or more yarns are an aramid yarn. Moreover, the first layer acts as a strengthening member for the plurality of tight buffered fibers. The second layer is a low smoke zero halogen layer. Further, the optical fiber cable has a cable diameter of about 3.7 millimeters. Furthermore, the optical fiber cable has an aerial span length in a range of 30 meters to 35 meters.

BRIEF DESCRIPTION OF FIGURES
[0023] Having thus described the disclosure in general terms, reference will now be made to the accompanying figures, wherein:

[0024] FIG. 1A illustrates a cross sectional view of an optical fiber cable, in accordance with an embodiment of the present disclosure; and

[0025] FIG. 1B illustrates a perspective view of the optical fiber cable of FIG. 1A, in accordance with an embodiment of the present disclosure.

[0026] 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.

DETAILED DESCRIPTION
[0027] Reference will now be made in detail to selected embodiments of the present disclosure in conjunction with accompanying figures. The embodiments described herein are not intended to limit the scope of the disclosure, and the present disclosure should not be construed as limited to the embodiments described. This disclosure may be embodied in different forms without departing from the scope and spirit of the disclosure. It should be understood that the accompanying figures are intended and provided to illustrate embodiments of the disclosure described below and are not necessarily drawn to scale. In the drawings, like numbers refer to like elements throughout, and thicknesses and dimensions of some components may be exaggerated for providing better clarity and ease of understanding.

[0028] It should be noted that the terms "first", "second", and the like, herein do not denote any order, ranking, quantity, or importance, but rather are used to distinguish one element from another. Further, the terms "a" and "an" herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item.

[0029] FIG. 1A illustrates a cross sectional view of an optical fiber cable 100, in accordance with various embodiments of the present disclosure. The optical fiber cable 100 is a drop optical fiber cable. The optical fiber cable 100 is used for drop installation. In addition, the optical fiber cable 100 is used for riser and plenum applications. Further, the optical fiber cable 100 is used for aerial installations, underground installations, indoor installations and the like. Also, the optical fiber cable 100 is used for broadband applications, communication applications and the like. In an embodiment of the present disclosure, the optical fiber cable 100 is a dual fiber cable. In addition, the dual fiber cable corresponds to two optical fibers. The optical fiber cable 100 is a rugged drop optical fiber cable. Further, the optical fiber cable 100 has a small diameter which makes the optical fiber cable 100 rugged and suitable for drop installation.

[0030] As shown in the FIG. 1A, the optical fiber cable 100 includes a plurality of tight buffered fibers, a first layer 106 and a second layer 108 (as seen in FIG. 1A in conjunction with the perspective view of the optical fiber cable 100 provided in FIG. 1B). In addition, the optical fiber cable 100 includes a plurality of water swellable yarns 110a-110bc and a plurality of ripcords 112a-112b. The optical fiber cable 100 is used to transmit optical signals (which may carry sensor data or communication data).

[0031] Further, the optical fiber cable 100 includes the plurality of tight buffered fibers. The plurality of tight buffered fibers lies substantially along a longitudinal axis of the optical fiber cable 100. Each of the plurality of tight buffered fibers has a tight buffer coating of nylon. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers has coating made of polyamides. In general, nylon is a tough, light weight, elastic synthetic polymer with a protein like chemical structure. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers has a tight nylon layer. Further, the nylon coating is used for making the optical fiber cable 100 rugged. In addition, the tight buffer nylon coating avoids the need for filling a gel. In an embodiment of the present disclosure, nylon is used due to hardness and low temperature performance. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers may be coated with thermoplastic elastomers. In an embodiment of the present disclosure, the coefficient of thermal expansion of the thermoplastic materials is around 1×10−4/K and 2×10−4/K.

[0032] In an embodiment of the present disclosure, the optical fiber cable 100 is a tight buffered fiber cable. In addition, the tight buffered fiber cable corresponds to a cable in which a single optical fiber is surrounded by a coating. In general, the tight buffered fiber cables are used as jumper cables which connect outside plant cables to terminal equipment. Also, the tight buffered fiber cables are used for linking various devices in a premises network. In addition, the tight buffered fiber cable has a rugged cable structure to protect the optical fiber during handling, routing and the like.

[0033] Furthermore, nylon exhibits efficient mechanical property. In an embodiment of the present disclosure, the tight buffered fiber provides mechanical protection and environmental protection for optical fiber. In addition, nylon is used due to a high Young’s modulus and a low thermal expansion coefficient. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers acts as a protective coating over the optical fiber.

[0034] Further, the plurality of tight buffered fibers includes a first tight buffered fiber and a second tight buffered fiber. In an embodiment of the present disclosure, a number of the plurality of tight buffered fibers is 2. In another embodiment of the present disclosure, the number of the plurality of tight buffered fibers is more or less than 2. The cross section of each of the plurality of tight buffered fibers is circular in shape. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers has a uniform structure and dimensions.

[0035] Each of the plurality of tight buffered fibers encloses the single optical fiber (as stated above in the patent application). The plurality of tight buffered fibers provides support and protection to the single optical fiber against crush, bend and stretch. In addition, the plurality of tight buffered fibers protects the single optical fiber and prevents ingression of water inside the core of the optical fiber cable 100. Further, the plurality of tight buffered fibers provides mechanical isolation, physical damage protection and identification of the optical fiber.

[0036] The first tight buffered fiber includes a first optical fiber 102 and a first tight buffered coating 102a. Accordingly, the first tight buffered coating 102a encloses the first optical fiber 102 and a second tight buffer coating 104a encloses the second optical fiber. In an embodiment of the present disclosure, the first tight buffered coating 102a tightly surrounds the first optical fiber 102. The second tight buffered fiber includes a second optical fiber 104 and a second tight buffer coating 104a. The second tight buffer coating 104a encloses the second optical fiber 104. In an embodiment of the present disclosure, the second tight buffered coating 104a tightly surrounds the second optical fiber 104. In an embodiment of the present disclosure, the first optical fiber 102 and the second optical fiber 104 are axially disposed. In an embodiment of the present disclosure, the tight buffer nylon coating is directly applied over the first optical fiber 102 and the second optical fiber 104. In an embodiment of the present disclosure, the tight buffer nylon coating is of about 600 micron. In addition, the thickness of the tight buffer nylon coating enables a reduction in overall diameter of the optical fiber cable 100.

[0037] Furthermore, each of the plurality of tight buffered fibers has an inner diameter and an outer diameter. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers has the inner diameter of about 0.25 millimeter. In another embodiment of the present disclosure, each of the plurality of tight buffered fibers has the inner diameter in a range of 250 micron ± 3 micron. In yet another embodiment of the present disclosure, the inner diameter of each of the plurality of tight buffered fibers may vary. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers has the outer diameter of about 0.60 millimeter. In another embodiment of the present disclosure, each of the plurality of tight buffered fibers has the outer diameter in a range of 600 micron ± 20 micron. In yet another embodiment of the present disclosure, the outer diameter of each of the plurality of tight buffered fibers may vary.

[0038] Further, the optical fiber is a fiber used for transmitting information as light pulses from one end to another. In addition, the optical fiber is a thin strand of glass or plastic capable of transmitting optical signals. Also, the optical fiber is configured to transmit large amounts of information over long distances with relatively low attenuation. Further, the optical fiber includes a core region and a cladding region. The core region is an inner part of an optical fiber and the cladding region is an outer part of the optical fiber.

[0039] The core region is defined by a central longitudinal axis of the optical fiber. In addition, the cladding region surrounds the core region. In an embodiment of the present disclosure, the radius of the optical fiber is maintained under a pre-defined value set as per the ITU-T standards. In addition, the optical signals to be transmitted travel through the core region of the optical fiber.

[0040] In an embodiment of the present disclosure, each of the optical fiber has a diameter of about 250 microns. In yet another embodiment of the present disclosure, the diameter of the optical fiber may vary. In an embodiment of the present disclosure, each of the optical fiber is a standard ITU-T G.652D silica optical fiber. In an embodiment of the present disclosure, the optical fiber is a single mode fiber. In another embodiment of the present disclosure, the optical fiber is a multimode fiber.

[0041] Accordingly, a total number of the optical fibers in the optical fiber cable 100 are 2 (1*2). In an embodiment of the present disclosure, the total number of the optical fibers may be more or less than 2 depending upon the number of tight buffered fibers and the optical fibers in each tight buffered fiber.

[0042] In an embodiment of the present disclosure, the optical fiber is a colored optical fiber. In another embodiment of the present disclosure, the optical fiber is not a colored optical fiber. In an embodiment of the present disclosure, each of the plurality of tight buffered fibers is colored. In an embodiment of the present disclosure, the first tight buffered fiber is blue in color. In another embodiment of the present disclosure, the first tight buffered fiber may have any other color. In an embodiment of the present disclosure, the second tight buffered fiber is yellow in color. In another embodiment of the present disclosure, the second tight buffered fiber may have any other color.

[0043] Going further, the optical fiber cable 100 includes the first layer 106. The first layer 106 surrounds the plurality of tight buffered fibers. In an embodiment of the present disclosure, the first layer 106 surrounds the first tight buffered fiber and the second tight buffered fibers. In addition, the first layer 106 includes one or more yarns. The one or more yarns are an aramid yarn. In an embodiment of the present disclosure, the one or more yarns may be of any other type. In an embodiment of the present disclosure, the first layer 106 acts as a binding element for the plurality of tight buffered fibers.

[0044] In an embodiment of the present disclosure, each of the one or more yarns is a binder yarn. Each of the one or more yarns is a yarn thread. Moreover, the first layer 106 acts as a strengthening member for the plurality of tight buffered fibers. In an embodiment of the present disclosure, the one or more yarns provide tensile strength to the optical fiber cable 100. In general, the tensile strength corresponds to a resistance shown by the optical fiber cable 100 against breaking when tension is applied. In an embodiment of the present disclosure, the tensile strength of the optical fiber cable 100 is about 500 Newton. In an embodiment of the present disclosure, the optical fiber cable 100 has a crush resistance of about 500 Newton.

[0045] In an embodiment of the present disclosure, the binder yarn facilitates absorption of water and moisture. In addition, each of the one or more yarns prevents ingression of the water inside the optical fiber cable 100. In an embodiment of the present disclosure, the number of the aramid yarn is 8. In an embodiment of the present disclosure, the optical fiber cable 100 may have any number of aramid yarns. In an embodiment of the present disclosure, the aramid yarn has a linear density of 1610 decitex. In addition, 1610 decitex corresponds to 1.61 kilograms of aramid yarn per 10,000 meter length of the aramid yarn. In addition, the first layer 106 binds the plurality of tight buffered fibers. In an embodiment of the present disclosure, the first layer 106 acts as a strengthening element for the plurality of tight buffered fibers.

[0046] The first layer 106 is characterized by a thickness. In an embodiment of the present disclosure, the first layer 106 has a thickness of about 0.40 millimeter. In yet another embodiment of the present disclosure, the thickness of the first layer 108 may vary. In an embodiment of the present disclosure, the first layer 106 is yellow in color. In another embodiment of the present disclosure, the first layer 106 may be of any color.

[0047] Further, the optical fiber cable 100 includes the second layer 108. The second layer 108 surrounds the first layer 106. In addition, the second layer 108 is a low smoke zero halogen layer. In an embodiment of the present disclosure, the second layer 108 is made of low smoke zero halogen. In an embodiment of the present disclosure, the second layer 108 is a low smoke zero halogen outer jacket for ultraviolet protection for indoor - outdoor purposes. In an embodiment of the present disclosure, the second layer 108 is an outer jacket of the optical fiber cable 100. In an embodiment of the present disclosure, the second layer 108 is made of any other suitable material. The suitable material includes thermoplastic polyurethane, polyethylene based flame retardant material and the like. In addition, the low smoke zero halogen is a flame retardant material which keeps the optical fiber cable 100 from catching fire. In an embodiment of the present disclosure, the second layer 108 is ultraviolet proof and provides protection to the optical fiber cable 100. The low smoke zero halogen reduces an amount of toxic and corrosive gas emitted during combustion.

[0048] The second layer 108 is characterized by a thickness. In an embodiment of the present disclosure, the second layer 108 has a thickness of about 0.85 millimeter. In yet another embodiment of the present disclosure, the thickness of the second layer 108 may vary. In an embodiment of the present disclosure, the second layer 108 is black in color. In another embodiment of the present disclosure, the second layer 108 may be of any color. The second layer 108 layer interacts directly with ambient environment. In addition, the second layer 108 is a sheathing layer. The second layer 108 protects the optical fiber cable 100 against the crush, the bend and tensile stress along the length of the optical fiber cable 100.

[0049] Going further, the optical fiber cable 100 includes the plurality of water swellable yarns 110a-110b. The plurality of water swellable yarns 110a-110b extends along the longitudinal axis of the optical fiber cable 100. In an embodiment of the present disclosure, the plurality of water swellable yarns 110a-110b is positioned adjacent to the plurality of tight buffered fibers. The plurality of water swellable yarns 110a-110b prevents ingression of water inside a core of the optical fiber cable 100. In an embodiment of the present disclosure, the number of the plurality of water swellable yarns 110a-110b is 2. In another embodiment of the present disclosure, the number of the plurality of water swellable yarns 110a-110b may vary.

[0050] Further, the optical fiber cable 100 includes the plurality of ripcords 112a-112b. In an embodiment of the present disclosure, the plurality of ripcords 114a-114b is placed inside the core of the optical fiber cable 100. The plurality of ripcords 112a-112b extends along the longitudinal axis of the optical fiber cable 100. The plurality of ripcords 112a-112b facilitates access to the one or more optical fibers. In an embodiment of the present disclosure, the plurality of ripcords 112a-112b lies substantially along the longitudinal axis of the optical fiber cable 100.

[0051] In an embodiment of the present disclosure, the plurality of ripcords 112a-112b is made of at least one of a polyester material and aramid. In another embodiment of the present disclosure, the plurality of ripcords 112a-112b is made of any suitable material. In an embodiment of the present disclosure, each of the plurality of ripcords 112a-114b has a circular cross-section. In an embodiment of the present disclosure, a number of the plurality of ripcords 112a-112b is 2. In another embodiment of the present disclosure, the number of the plurality of ripcords 112a-112b may vary.

[0052] In addition, the optical fiber cable 100 has a cable diameter of about 3.7 millimeters. In an embodiment of the present disclosure, the optical fiber cable 100 has the cable diameter in a range of 3.7 millimeters ± 0.2 millimeter. In an embodiment of the present disclosure, the cable diameter is reduced due to the 600 micron nylon coating. In an embodiment of the present disclosure, the optical fiber cable has a core diameter of about 2 millimeters. In addition, the optical fiber cable 100 has an aerial span length in a range of 30 meters to 35 meters. The aerial span length corresponds to a length of the optical fiber cable 100 between two poles. In an embodiment of the present disclosure, the optical fiber cable 100 is compatible with Field mountable connectors. The reduced diameter allows the optical fiber cable 100 to fit properly inside the Field mountable connectors.

[0053] It may be noted that in FIG. 1A and FIG. 1B, the optical fiber cable 100 includes two tight buffered fibers; however, those skilled in the art would appreciate that more or less number of tight buffered fibers are included in the optical fiber cable 100.

[0054] The optical fiber cable has numerous advantages over the prior art. The optical fiber cable is used for indoor - outdoor installation. In addition, the optical fiber cable has a small diameter due to the 600 micron tight buffer nylon coating. In addition, the optical fiber cable has a large aerial span length. Moreover, the optical fiber is compatible with the Field mountable connectors (FMC). The small diameter allows the optical fiber cable to fit properly inside the Field mountable connectors (FMC). Further, the optical fiber cable provides low signal attenuation. Furthermore, the optical fiber cable is insensitive to bends.

[0055] The foregoing descriptions of pre-defined embodiments of the present technology have been presented for purposes 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.