DESC:

TECHNICAL FIELD
[0001] The present disclosure relates to the field of optical fiber ribbons and cables. More specifically, the present disclosure relates to a high density superbundled optical fiber cable and a method and a system for rebundling optical fiber ribbon bundles.

PRIORITY DETAILS
[0002] The present application claims the benefit of Provisional Application No. 20111002365, filed on 19/01/2021.

BACKGROUND
[0003] An optical fibre cable plays a pivotal role in today's networking infrastructure. The optical fiber cable carries data faster than conventional copper cables and has complex designs and intensive underground laying procedures. The demand for uninterrupted and high speed internet is consistently paving a way for new design of the optical fiber cable. Over decades, the consistent development in the optical fiber cable industry leads to innovative cable designs that can accommodate more optical fibers within the current limited duct space.

[0004] The optical fiber cable is designed to have maximum number of optical fibers, to be easy to access and to be easy to tear and cut whenever required. In one of the configurations, the optical fibers are placed longitudinally in groups (12 fibers, 24 fibers or the like) and bonded with a bonding material to form optical fiber ribbons. The optical fiber ribbons are grouped together to form optical fiber ribbon bundles.

[0005] In a high fiber count optical fiber cable like 6912F cable, a total of 24 bundles have 288 fibres each. Sheathing of the 24 bundles simultaneously becomes difficult since the optical fiber cable has ripcords, water swellable yarns, water blocking tape and strength members apart from the 24 bundles. Such sheathing process with a large number of moving parts becomes difficult to monitor and may cause damage. In addition, the bundling of the 24 bundles together in a core like structure to avoid using the 24 bundles individually causes fibre breaks due to the sheer weight of 6912 fibers.

[0006] There are a few patent applications which provide a high density superbundled optical fiber cable. In an example, the patent application DE10111274A1 discloses bundling of loose fibers and assembling of the bundles to form sub cables is provided. In another example, the patent application DE60030375T2 discloses grouping of fibers with colored water swellable binders and binding of all the groups with a water swellable material to avoid use of water blocking gel. In yet another example, the patent application EP1018662B1 discloses an optical cable having a cable core of multiple stranded elements and having an outer jacket enveloping the cable core. In yet another example, the patent application US2011110635A1 discloses an optical fiber ribbon having two-dimensionally disposed resin portions for bonding the adjacent 2-fiber mono-coated optical fibers in plural places.

[0007] In the light of the above stated discussion, there is a need to ameliorate one or more of the aforementioned disadvantages by providing a high density superbundled optical fiber cable and a method and a system for rebundling optical fiber ribbon bundles.

OBJECT OF THE DISCLOSURE
[0008] A primary object of the present disclosure is to provide a high density superbundled optical fiber cable.

[0009] Another object of the present disclosure is to eliminate optical fiber breaks which occur due to weight of the optical fibers bundle and high take-up tension.

[0010] Another object of the present disclosure is to provide an optical fiber cable comprising a plurality of superbundles, with each superbundle comprising a plurality of ribbon bundles, each ribbon bundle comprising rolled optical fiber ribbons.

SUMMARY
[0011] In an aspect, the present disclosure provides an optical fiber cable. The optical fiber cable includes a plurality of superbundles. In addition, the optical fiber cable includes a sheath enclosing the plurality of superbundles. Further, each superbundle of the plurality of superbundles has a plurality of bundles. Furthermore, each bundle has one or more optical fiber ribbons. Moreover, the one or more optical fiber ribbons are rolled.

STATEMENT OF THE DISCLOSURE
[0012] The present disclosure provides an optical fiber cable. The optical fiber cable includes a plurality of superbundles. In addition, the optical fiber cable includes a sheath enclosing the plurality of superbundles. Further, each superbundle of the plurality of superbundles has a plurality of bundles. Furthermore, each bundle has one or more optical fiber ribbons. Moreover, the one or more optical fiber ribbons are rolled

BRIEF DESCRIPTION OF THE FIGURES
[0013] Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
[0014] FIG. 1 illustrates a cross-sectional view of an optical fiber cable with a plurality of superbundles, in accordance with various aspects of the present disclosure;
[0015] FIG. 2 illustrates a cross-sectional view of a superbundle of the plurality of superbundles, in accordance with an aspect of the present disclosure;
[0016] FIG. 3 illustrates a system for forming the plurality of superbundles, in accordance with an aspect of the present disclosure; and
[0017] FIG. 4 illustrates a flow diagram of a method for forming the plurality of superbundles, in accordance with an aspect of the present disclosure.
[0018] It should be noted that the accompanying figures are intended to present illustrations of exemplary depictions 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
[0019] Reference in this specification to “one aspect” means that a particular feature, structure, or characteristic described in connection with the aspects included in at least one aspect of the present technology. The appearance of the phrase “in one aspect” in various places in the specification are not necessarily all referring to the same aspect, nor are separate or alternative aspects mutually exclusive of other apects. Moreover, various features are described which may be exhibited by some aspects and not by others. Similarly, various requirements are described which may be requirements for some aspects but no other aspects.
[0020] Reference will now be made in detail to selected aspects of the present disclosure in conjunction with accompanying figures. The aspects described herein are not intended to limit the scope of the disclosure, and the present disclosure should not be construed as limited to the aspects 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 aspects 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.
[0021] 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.
[0022] 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.

[0023] FIG. 1 illustrates a cross-sectional view of an optical fiber cable 100 with a plurality of superbundles 102-112, in accordance with various aspects of the present disclosure. FIG. 2 illustrates a cross-sectional view of a superbundle 102 of the plurality of superbundles 102-112, in accordance with an aspect of the present disclosure. In general, an optical fiber cable includes a plurality of fibers and carries information in the form of data between two places using light technology. In an aspect of the present disclosure, the optical fiber cable 100 has a total of six superbundles. In another aspect of the present disclosure, the optical fiber cable 100 may have any other number of superbundles. In addition, the optical fiber cable 100 has a filling coefficient of at least 35%. In general, the filling coefficient is the ratio of total cross sectional area of all fibers to the inner cross sectional area of sheath.

[0024] The optical fiber cable 100 includes a sheath 114. The sheath 114 encloses the plurality of superbundles 102-112. Each superbundle of the plurality of superbundles 102-112 includes a plurality of bundles 116, one or more binders 118 and one or more water swellable yarns 120. In addition, each bundle in the plurality of superbundles 102-112 is held together by at least one of the one or more binders 118, water blocking tape, an aramid yarn(s), a glass roving yarn(s) and a metal tape. Further, each bundle of the plurality of bundles 116 has one or more optical fiber ribbons. Furthermore, the one or more optical fiber ribbons are rolled.

[0025] The plurality of bundles 116 is formed by bundling the one or more optical fiber ribbons. In an aspect of the present disclosure, the one or more optical fiber ribbons are rolled and bundled using the one or more binders 118. In an example, the one or more binders 118 include binder yarns where the rolled ribbons (or optical fiber ribbons) may be bent in a near-circular shape. In another aspect of the present disclosure, the one or more optical fiber ribbons may be bundled using any other suitable means. The binder yarns may be coloured binder yarns. The binder yarns may be of same or of different colour. In addition, the binder yarns may be made of any suitable material.

[0026] The one or more optical fiber ribbons include a plurality of optical fibers. The plurality of optical fibers are intermittently bonded and form one or more intermittently bonded ribbons. The one or more optical fiber ribbons may be any of the intermittently bonded ribbons, flat ribbon and rollable ribbons. In addition, the plurality of optical fibers is placed in parallel and adjacent optical fibers are bonded with special material intermittently along a longitudinal length and width. Further, the bonding with special material converts the plurality of optical fibers into intermittently bonded ribbons. The flexible matrix material between adjacent optical fibers may take a corrugated shape, concave shape, convex shape, flat shape or any other suitable shape. Furthermore, the joining of the plurality of optical fibers with a special material imparts rollable capability to the one or more optical fiber ribbons. The one or more optical fiber ribbons may be rolled and packed efficiently. The packed bundles of the one or more optical fiber ribbons are easy to handle and are used to further make an efficiently packed superbundle.

[0027] In an aspect, the plurality of optical fibers may have a diameter of 250±10µm. In another aspect, the plurality of optical fibers may have a diameter of 200±10µm. In yet another aspect, the plurality of optical fibers may have a diameter of 160±10µm. Alternatively, the plurality of optical fibers may have other suitable diameter. In general, an optical fiber refers to a medium associated with signal transmission over long distances in the form of light pulses. The optical fiber uses light to transmit voice and data communications over long distances when encapsulated in a jacket. The plurality of optical fibers may be single-mode optical fibers or multi- mode optical fibers. The plurality of optical fibers may be of ITU.T G.657A2 category. Alternatively, the plurality of optical fibers may be of ITU.T G.657A1 or G.657B3 or G.652D or other category. The plurality of optical fibers may be coloured fibers. The one or more optical fiber ribbons may have a pitch of 250µm. Alternatively, the pitch may vary. The one or more optical fiber ribbons may use colour coded ribbon matrix, band stripe printing or the like for ribbon identification.

[0028] The one or more water swellable yarns 120 act as a water blocking element. The one or more water swellable yarns 120 prevent water ingression in the plurality of bundles 116. In an aspect, the one or more water swellable yarns 120 may be placed inside at least one of the plurality of superbundles 102-112, inside at least one of the plurality of bundles 116 and in-between bundle of the plurality of superbundles 102-112. In another aspect of the present disclosure, the one or more water swellable yarns 120 may be located in a core of an optical fiber cable 100. In another aspect of the present disclosure, the one or more water swellable yarns 120 may be placed inside one or more of the plurality of bundles 116. In addition, the one or more water swellable yarns 120 may be placed inside the plurality of superbundles 102-112. In an implementation, there may be three water swellable yarns 120. In another implementation, the number of the water swellable yarns 120 may vary. Further, the one or more water swellable yarns 120 may have a weight as 9000 denier. Alternatively, the one or more water swellable yarns 120 may have other suitable weight. In an implementation, the plurality of superbundles 102-112 may be formed without the one or more water swellable yarns 120.

[0029] The plurality of bundles 116 and the one or more water swellable yarns 120 are placed longitudinally and bundled using the one or more superbinders 122. In an aspect of the present disclosure, the one or more superbinders 122 may be the binder yarns. In another aspect of the present disclosure, the one or more superbinders 122 may be any other suitable means. In an aspect, the plurality of bundles 116 and the one or more water swellable yarns 120 are SZ stranded to form a superbundle of the plurality of superbundles 102-112. In general, the SZ stranding includes two turns of 4 bundles of the plurality of bundles in clockwise direction. The plurality of bundles 116 have a defined lay-length followed by two turns in anti-clockwise direction with same lay-length, where the process is repeated. In general, lay length is the longitudinal distance required to complete one revolution of the strand either in S or Z direction. The number of bundles and turns may vary. Further, in an aspect of the present disclosure, each bundle of the plurality of superbundle 102-112 has a filling coefficient of at least 70%. In an aspect of the present disclosure, the filling coefficient is the ratio of total cross sectional area of all the fibers to the cross sectional area of an imaginary circle with minimum diameter enclosing all the fibers.
[0030] In an aspect of the present disclosure, a plurality of smaller ribbon bundles (such as 24 ribbons*12F) are made using rollable ribbons. The rollable ribbons are rolled in a near-circular fashion and grouped together using the one or more binders 118. The ribbon bundles with rollable ribbons allow to achieve a compact superbundle with less optical attenuation of the fibers during the binding process. In general, the optical attenuation refers to the loss of power of any signal over a range of distance. The ribbon bundles made of rollable ribbons are capable of adjusting shape according to the stress experienced. Further, the plurality of smaller ribbon bundles are circular in shape to allow easy handling. Furthermore, the circular shape allows application of SZ stranding process similar to buffer tubes to obtain the plurality of superbundles 102-112.
[0031] In an aspect, the plurality of superbundles 102-112 may be grouped by one or more superbinders 122. In an aspect, the one or more superbinders 122 are equivalent to two binders and the two binders are applied contra helically. In an aspect, the one or more superbinders 122 may be colored. In an aspect, the one or more superbinders 122 may be coated with one of a water swellable material and a retardant material. In an aspect, the one or more superbinders 122 are wound at a lay length of 30 to 60 millimetres. In an aspect, the application of single binder to the plurality of superbundle 102-112may experience increase in lay length during handling process which causes the superbundle to open up or bulge out.. The use of contra-helical binding keeps the binder positions intact as compared to a single binder.
[0032] In an aspect, the plurality of superbundles 102-112 may be placed longitudinally in the optical fiber cable 100 during manufacturing of the optical fiber cable 100. Each superbundle of the plurality of superbundles 102-112 includes the plurali]ty of bundles 116. In addition, each bundle of the plurality of bundles 116 has the one or more optical fiber ribbons placed in rolled manner and bundled using the one or more binders 118 as described above. The plurality of superbundles 102-112 may be further enclosed by at least one of a water blocking tape, aramid yarn(s), glass roving yarn(s), and metal tape.
[0033] In an example, for a high fiber count optical fiber cable 100, a total number of optical fibers may be 6912 but not limited to the mentioned number. The 6912 fibers may be arranged and bundled into 6 superbundles, where each superbundle may have 4 ribbon bundles, each ribbon bundle may have 24 ribbons and each ribbon may have 12 fibers. In an aspect, the above mentioned arrangement of the optical fiber cable 100 helps elimination of fiber breaks that occur due to weight of the optical fibers and high take-up tensions. In another aspect, other arrangements of the opt ical fiber cable 100 are also possible.
[0034] Further, each bundle in the high fiber count optical fiber cable having 6912F has 288 fibers (24 ribbons * 12 F). Furthermore, the plurality of superbundles 102-112 reduces the number of moving parts from 24 bundles (24*12F) to 6 superbundles (1152F). Moreover, the superbundling requires a less number of color combinations of binders for identification. Each superbundle 102-112 has a different identification color and the plurality of bundles 116 inside each superbundle of the plurality of superbundles 102-112 may have same identification colors.
[0035] In addition, the sheer weight of 6912 fiber tends to break fiber ribbons during the pulling process upon simultaneously using the 24 bundles individually and bundling in a core like structure. In an aspect, the plurality of superbundles 102-112 (4 bundles * 24 ribbons * 12 fibers) minimizes the above mentioned problems. The number of moving parts gets reduced (6 superbundles instead of 24 bundles) during the sheathing process. Further, the reduction in total weight (1152F) to less than 6912F avoids breaking of ribbons during bundling. Furthermore, the super bundling also helps in the easier handling of large number of optical fibers during the installation.

[0036] The sheath 114 surrounds the plurality of superbundles 102-112. In an aspect, the sheath 114 is a high density polyethylene (HDPE) jacket. In another aspect, the sheath 114 may be made of any other suitable material. The outer sheath 114 is characterized by a thickness of 2-3.5 mm. In an aspect, the thickness of the outer sheath 114 may vary. In an aspect, the outer sheath 114 is black in color. In another aspect, the outer sheath 114 may be of any color. In an aspect, the outer sheath 114 may be embedded with strength members. The outer sheath 114 layer interacts directly with ambient environment. In addition, the outer sheath 114 is a jacketing layer. The sheath 114 protects the optical fiber cable 100 against crush, bend and tensile stress along the length of the optical fiber cable 100.

[0037] FIG. 3 illustrates a system 200 for forming the plurality of superbundles 102-112, in accordance with an aspect of the present disclosure. The system 200 includes a payoff unit 202, a cop unit 204, an oscillator 206, a binder unit 208 and a take-up unit 210. The payoff unit 202 pays off the plurality of bundles 116 to the oscillator 206. Simultaneously, the cop unit 204 provides the one or more water swellable yarns 120 to the oscillator 206. The oscillator 206 gives SZ stranding and lay length to the plurality of bundles 116 and combines the plurality of bundles 116 with the one or more water swellable yarns 120. In an example, there may be four ribbon bundles and three water swellable yarns as depicted in FIG. 2. Other combinations are also possible. Further, the lay length may range between 1000mm to 2500mm. Alternatively, the plurality of superbundles 102-112 may be formed without the one or more water swellable yarns 120.

[0038] The binder unit 208 binds a combination of the plurality of bundles 116 and the one or more water swellable yarns 120. The binding is done using the one or more superbinders 122and transferred to the take up unit 210. In addition, the take-up unit 210 winds one superbundle of the plurality of superbundles 102-112 on a drum.

[0039] FIG. 4 is a flow chart 300 illustrating a method for forming the plurality of superbundles 102-112, in accordance with an aspect of the present disclosure. The steps 302 to 310 are performed by the system 200.

[0040] At step 302, the method includes paying off the plurality of bundles 116 from the payoff unit 202 to the oscillator 206. Simultaneously, at step 304, the method includes providing the one or more water swellable yarns 120 from the cop unit 204 to the oscillator 206. At step 306, the method includes providing the SZ stranding and the lay length to the plurality of bundles 116. In addition, the step 306 includes combining the plurality of bundles 116 with the one or more water swellable yarns 120 by the oscillator 206. At step 308, the method includes binding the combined plurality of bundles 116 and the one or more water swellable yarns 120 by the binder unit 208 and forming the plurality of superbundles 102-112. At step 310, the method includes winding the plurality of superbundles 102-112 by the take-up unit 210 on the drum.

[0041] The foregoing descriptions of pre-defined aspects 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 aspects 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 aspects 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.

CLAIMS:CLAIMS

We claim:
1. An optical fiber cable (100) comprising:

a plurality of superbundles (102-112), wherein each superbundle of the plurality of superbundles (102-112) has a plurality of bundles (116), wherein each bundle has one or more optical fiber ribbons, wherein the one or more optical fiber ribbons are rolled; and

a sheath (114) enclosing the plurality of superbundles (102-112).

2. The optical fiber cable (100) as recited in claim 1, wherein the one or more rolled optical fiber ribbons are bundled using one or more bundle binders (118).

3. The optical fiber cable (100) as recited in claim 1, wherein the plurality of bundles (116) are SZ stranded to form a superbundle of the plurality of superbundles (102-112).

4. The optical fiber cable (100) as recited in claim 1, wherein each bundle in the plurality of superbundles (102-112) is held together by at least one of one or more binders (118), a water blocking tape, an aramid yarn(s) and a glass roving yarn(s)..

5. The optical fiber cable (100) as recited in claim 1, wherein each of the plurality of superbundles (102-112) is held together by at least one of one or more superbinders (122), a water blocking tape, an aramid yarn(s), a glass roving yarn(s) and a metal tape.

6. The optical fiber cable (100) as recited in claim 5, wherein the one or more superbinders (122) are equivalent to two binders and wherein the two binders are applied contra helically.

7. The optical fiber cable (100) as recited in claim 1, further comprising one or more water swellable yarns (120), wherein the one or more water swellable yarns (120) are placed inside at least one of the plurality of superbundles (102-112), inside at least one of the plurality of bundles (116) and in-between bundle of the plurality of superbundles (102-112).

8. The optical fiber cable (100) as recited in claim 5, wherein the one or more superbinders (122) are colored.

9. The optical fiber cable (100) as recited in claim 5, wherein the one or more superbinders (122) are coated with one of a water swellable material and a fire retardant material.

10. The optical fiber cable (100) as recited in claim 1, wherein each bundle (116) of the plurality of superbundles (102-112) has a filling coefficient of at least 70%.

11. The optical fiber cable (100) as recited in claim 5, wherein the one or more superbinders (122) are wound at a lay length of 30 to 60 millimetres.

12. The optical fiber cable (100) as recited in claim 1, wherein the plurality of bundles (116) are SZ stranded at a lay length in a range of 250 millimetres to 350 millimetres to make a superbundle of the plurality of superbundles (102-112).