[0001] The present invention relates to the field of optical communication technology and, in particular, relates to a ribbed and grooved cable. The present application is based on, and claims priority from an Indian Application Number 202011031302 filed on 22nd July, 2020, the disclosure of which is incorporated herein.

BACKGROUND
[0002] With the advancement of science and technology, various modern technologies are being employed for communication purposes. One of the most important modern communication technologies is optical fiber communication technology using a variety of optical fiber cables. The optical fiber cables are widely used for communication to meet increasing bandwidth and data transmission demands. Further, installation of the optical fiber cables at a rapid pace becomes essential. Furthermore, the optical fiber cables for telecommunication application are installed in ducts. Moreover, the installation of the optical fiber cables in the ducts is mostly performed using a blowing method. Also, the blowing method to install the optical fiber cables in the ducts is dependent on a plurality of factors. The plurality of factors includes mass of the optical fiber cable, friction, stiffness, and the like. Also, the blowing method enables installation of the optical fiber cable using pressurized air combined with additional mechanical pushing force that is called as “blowing”. Also, the blowing method is the process of installation of the optical fiber cable into a pre-installed duct. The blowing is performed by injecting pressurized air in inlet of the pre-installed duct before the optical fiber cable is pushed into the pre-installed duct. The pressurized air flows at high speed through the pre-installed duct and along the optical fiber cable. Also, pushing force is applied near the optical fiber cable inlet by a pushing device. The optical fiber cable includes uni-tube, multi-tube, unarmoured, armoured, micro duct cable, and the like. However, conventional structure of optical fiber cable makes it inefficient to allow pressurized air to blow the optical fiber cable in the pre-installed duct. In addition, the conventional optical fiber cable resists the pushing force due to higher coefficient of friction. Further, the conventional optical fiber cable has higher number of contact points with the pre-installed duct. Furthermore, the conventional optical fiber cable has heavy weight.
[0003] In light of the above-stated discussion, there exists a need for an optical fiber cable that overcomes the above cited drawbacks of the conventional optical fiber cable.

OBJECT OF THE DISCLOSURE
[0004] A primary object of the present disclosure is to provide a ribbed and grooved cable.
[0005] Another object of the present disclosure is to provide the cable with corrugated sheath.
[0006] Another object of the present disclosure is to provide the cable with high/optimized blowing performance.

SUMMARY
[0007] Accordingly, the present disclosure provides an optical fiber cable with high blowing performance. The optical fiber cable is a ribbed and grooved cable. The optical fiber cable includes a plurality of optical fiber ribbon bundles, a plurality of water swellable yarns, water blocking tape, sheath, a plurality of strength members and one or more ripcords. The sheath is a corrugated sheath having a plurality of ribs and a plurality of grooves on an outer surface of the corrugated sheath, where the plurality of ribs is longitudinal protrusions on the outer surface of the corrugated sheath and is parallel to an axis of the optical fiber cable and the plurality of strength members embedded in the corrugated sheath such that the plurality of strength members is placed under the plurality of ribs. The plurality of ribs has at least two different heights. The plurality of ribs on the corrugated sheath can be continuous or discontinuous. The plurality of strength members embedded in the corrugated sheath has a diameter less than a width of the plurality of ribs at bottom of the plurality of ribs. The plurality of strength members embedded in the corrugated sheath such that the plurality of strength members is radially equidistant from a geometric center of the optical fiber cable. The plurality of strength members embedded in the corrugated sheath such that each of the plurality of strength members is spaced apart at equal angular distance in the corrugated sheath. The plurality of strength members embedded in the corrugated sheath can be equal or less than number of the plurality of ribs. The plurality of strength members is positioned below the plurality of ribs or may partially overlap the plurality of ribs.
[0008] These and other aspects herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawing. It should be understood, however, that the following descriptions are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the invention herein without departing from the spirit thereof.

STATEMENT OF THE DISCLOSURE
[0009] The present disclosure provides an optical fiber cable with high blowing performance. The optical fiber cable is a ribbed and grooved cable. The optical fiber cable includes a plurality of optical fiber ribbon bundles, a plurality of water swellable yarns, a water blocking tape, a sheath with a plurality of ribs and a plurality of grooves, a plurality of strength members and one or more ripcords. The plurality of ribs and the plurality of grooves are formed on outer surface of the sheath. The plurality of ribs includes a first type of ribs and a second type of ribs. The first type of ribs and the second type of ribs are arranged alternately to each other. The first type of ribs has a height larger than the second type of ribs. The varying height of the plurality of ribs enables reduction in coefficient of friction between the sheath and a duct. The plurality of ribs and the plurality of grooves reduce weight of the optical fiber cable. Also, each of the plurality of strength members is embedded in the sheath. The plurality of strength members enhances blowing performance of the optical fiber cable by increasing stiffness of the optical fiber cable. The plurality of strength members also provides tensile strength to the optical fiber cable. The plurality of strength members is positioned below the plurality of ribs. In addition, the plurality of strength members is coated with EAA (Ethylene acrylic acid).

BRIEF DESCRIPTION OF THE FIGURES
[0010] The invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the figure. The invention herein will be better understood from the following description with reference to the drawings, in which:
[0011] FIG. 1 and FIG. 1a illustrate a first design of a sheath of an optical fiber cable.
[0012] FIG. 2 illustrates a second design of the sheath of the optical fiber cable having a plurality of strength members embedded under the larger ribs only.
[0013] FIG. 3 illustrates a third design of the sheath of the optical fiber cable having a plurality of strength members embedded under the smaller ribs only.
[0014] FIG. 4 illustrates a fourth design of the sheath showing a plurality of ribs in a discontinuous configuration for the optical fiber cable.
[0015] FIG. 5 illustrates a fifth design of the sheath having a plurality of strength members embedded partially inside the plurality of ribs.

DETAILED DESCRIPTION
[0016] In the following detailed description of the invention, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, it will be obvious to a person skilled in the art that the invention may be practiced with or without these specific details. In other instances, well known methods, procedures and components have not been described in details so as not to unnecessarily obscure aspects of the invention.
[0017] Furthermore, it will be clear that the invention is not limited to these alternatives only. Numerous modifications, changes, variations, substitutions and equivalents will be apparent to those skilled in the art, without parting from the scope of the invention.
[0018] The accompanying drawings are used to help easily understand various technical features and it should be understood that the alternatives presented herein are not limited by the accompanying drawings. As such, the present disclosure should be construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are generally only used to distinguish one element from another.
[0019] Referring now to the drawings, and more particularly to FIGS. 1 through 5.
[0020] FIG. 1 and FIG. 1a illustrates a first design of a sheath of an optical fiber cable 100. FIG. 2 illustrates a second design of a sheath of another optical fiber cable 100 having a plurality of strength members embedded under the larger ribs only. FIG. 3 illustrates a third design of the sheath of another optical fiber cable 100 having a plurality of strength members embedded under the smaller ribs only. FIG. 4 illustrates a fourth design of the sheath showing a plurality of ribs in a discontinuous configuration for the optical fiber cable 100. FIG. 5 illustrates a fifth design of the sheath having a plurality of strength members embedded partially inside the plurality of ribs. The optical fiber cable 100 is a ribbed and grooved cable. The optical fiber cable 100 has high blowing performance. The optical fiber cable 100 can be easily and quickly installed for desired application. The optical fiber cable 100 includes a plurality of optical fiber ribbon bundles 102, a plurality of water swellable yarns 108, a water blocking tape 110, the sheath 112 with a plurality of ribs 114 and a plurality of grooves 116, a plurality of strength members 118 and one or more ripcords 120.
[0021] The plurality of optical fiber ribbon bundles 102 are positioned inside a core of the optical fiber cable 100. The core is an inner part of the optical fiber cable 100 which is enclosed by a sheath and containing all the optical transmission elements or optical fibers. Each of the plurality of optical fiber ribbon bundles 102 includes a plurality of optical fiber ribbons 104 bundled with colored binders 106. Alternatively, the core of the optical fiber cable 100 may include a plurality of optical fiber bundles, a plurality of loose tubes bundles, a plurality of tight-buffered optical fibers bundles or bundles of any other suitable elements carrying optical fibers. The plurality of optical fiber ribbons 104 increase optical fiber density of an optical fiber cable 100. Each of the plurality of optical fiber ribbons 104 includes a number of optical fibers bonded together with a matrix material. In addition, optical fiber ribbons are used in optical fiber cables that require high fiber counts within less installation space. In general, optical fiber cables are used to transfer digital data signals in the form of light up to distances of hundreds of miles with higher throughput rates than those achievable via electrical communication cables. The optical fiber ribbons enable mass fusion splicing.
[0022] Each of the plurality of optical fiber ribbons 104 includes a plurality of optical fibers. Each of the plurality of optical fibers is used to transmit information as light pulses from one end to another. In addition, each of the plurality of optical fibers is a thin strand of glass or plastic capable for transmitting optical signals. Further, each of the plurality of optical fibers is configured to transmit large amounts of information over long distances with relatively low attenuation. Furthermore, each of the plurality of optical fibers includes a core region and a cladding region. The core region is an inner part of the optical fiber and the cladding section is an outer part of the optical fiber. Moreover, the core region is defined by a central longitudinal axis of each of the plurality of optical fibers. Also, the cladding region surrounds the core region. The core region and the cladding region are formed along the central longitudinal axis of each of the plurality of optical fibers. In addition, the core region and the cladding region are formed during the manufacturing stage of each of the plurality of optical fibers. The core region has a refractive index that is greater than a refractive index of the cladding region.
[0023] Each of the plurality of optical fiber ribbons 104 may be a flexible optical fiber ribbon. In addition, each of the plurality of optical fiber ribbons 104 may be a rollable ribbon, such as intermittently bonded optical fiber ribbon. Typically, the plurality of optical fibers is placed in parallel and bonded with a bonding material intermittently along a longitudinal length and width to convert the plurality of optical fibers into the intermittently bonded optical fiber ribbon. Moreover, each of the plurality of optical fiber ribbons 104 may be a bendable optical fiber ribbon. In general, bendable optical fiber ribbon refers to a ribbon that can easily bend along preferential as well as non-preferential axis. A number of the plurality of optical fibers in each of the plurality of optical fiber ribbons 104 may be 12. A number of the plurality of optical fibers in each of the plurality of optical fiber ribbons 104 may be more or less than 12. Alternatively, the number of the plurality of optical fibers in each of the plurality of optical fiber ribbons 104 may be 6-24 or may vary. Each of the plurality of optical fibers in each of the plurality of optical fiber ribbons 104 may have a diameter in a range of 150-250 micrometres. Each of the plurality of optical fiber ribbons 104 may have a pitch in a range of 150-250 micrometres. Typically, the pitch refers to a distance between centres of adjacent fibers in an optical fiber ribbon. Each of the plurality of optical fibers may be a single-core fiber. Alternatively, each of the plurality of optical fibers may be multicore fiber having different dimensions from the one stated above.
[0024] The plurality of optical fiber ribbons 104 is bundled together with colored binders 106 to form a single ribbon bundle. Binder can be a thread binder or polyester tape type binder. Multiple optical fiber ribbons 104 are bundled together to form a single ribbon bundle. The bundling is done with the help of the colored binders 106. There may be two or more than two colored binders to bind and form the single ribbon bundle. There may be a single colored binder to bind and form the single ribbon bundle. There are multiple number of bundles placed in the core of the optical fiber cable 100. In an example, a number of the plurality of optical fiber ribbon bundles 102 inside the core of the optical fiber cable 100 is 6 (as shown in FIG. 1). There may be more or less than 6 ribbon bundles in the optical fiber cable 100 depending on the requirement.
[0025] The colored binders 106 in each of the plurality of optical fiber ribbon bundles 102 are helically wrapped around the plurality of optical fiber ribbons 104. The colored binders 106 enable easy identification of each of the plurality of optical fiber ribbon bundles 102. In addition, the colored binders 106 are wrapped so as to not put much stress on the plurality of optical fibers of each of the plurality of optical fiber ribbons 104. The colored binders 106 enable sufficient binding to help maintain a compact shape. A total number of optical fibers in each of the plurality of optical fiber ribbon bundles 102 is 72 (12*6) with 6 ribbons and each ribbon having 12 optical fibers. So, a total number of optical fibers in the optical fiber cable 100 is 432 (72*6) with each 6 ribbon bundles and each ribbon bundle having 72 optical fibers. A total number of optical fibers in the optical fiber cable 100 may vary. Also, a total number of optical fibers in an optical fiber ribbon bundle may vary.
[0026] The optical fiber cable 100 may include the plurality of water swellable yarns 108. The plurality of water swellable yarns 108 is positioned inside the core of the optical fiber cable 100. The plurality of water swellable yarns 108 may be positioned along the plurality of optical fiber ribbon bundles 102. In addition, the plurality of water swellable yarns 108 may be positioned in spaces between the plurality of optical fiber ribbon bundles 102. The plurality of water swellable yarns 108 prevents ingression of water in the optical fiber cable 100. In addition, the plurality of water swellable yarns 108 is used to absorb moisture inside the optical fiber cable 100. A total number of the plurality of water swellable yarns 108 in the optical fiber cable 100 is 7 (as shown in FIG. 1). However, there may be lesser or more number of water swellable yarns in the optical fiber cable 100.
[0027] The optical fiber cable 100 may include the water blocking tape 110. The water blocking tape 110 surrounds the plurality of optical fiber ribbon bundles 102 and the plurality of water swellable yarns 108. In general, water blocking tape provides water resistance to optical fiber cables over long period of time. The water blocking tape 110 facilitates complete insulation and protects the optical fiber cable 100 against water ingression.
[0028] The optical fiber cable 100 includes the sheath 112. The sheath 112 is a corrugated sheath and includes an inner surface and an outer surface. In general, sheath is an outer layer of a cable that protects the cable from environmental conditions. In addition, the environment conditions include but may not be limited to rainfall, sunlight, snowfall, and wind. Typically, a conventional cable sheath has a smooth surface. Corrugation helps in reducing coefficient of friction between the optical fiber cable 100 and a duct by reducing the number of contact points, which provides increased blowing capacity to the optical fiber cable. The sheath (or the corrugated sheath) 112 of the optical fiber cable 100 includes the plurality of ribs 114 and the plurality of grooves 116. The plurality of ribs 114 and the plurality of grooves 116 are formed on the outer surface of the sheath 112. A number of the plurality of ribs 114 may be same as number of the plurality of grooves 116.
[0029] Each of the plurality of ribs 114 is a longitudinal protrusion formed on the outer surface of the sheath 112 and is parallel to an axis of the optical fiber cable 100. Each of the plurality of grooves 116 is formed between two consecutive ribs of the plurality of ribs 114. The plurality of ribs 114 includes a first type of ribs 114a and a second type of ribs 114b. Each rib of the first type of ribs 114a has large size. Each rib of the second type of ribs 114b has a smaller size as compared to the first type of ribs. Height of the first type of ribs (i.e., first height) is larger than height of the second type of ribs (i.e., second height) (as shown in FIG. 1a). In an example, during installation of the cable 100 into the duct, only the first type of ribs touches the duct. In addition, the second type of ribs does not touch the duct due to small size of the second type of ribs. The plurality of ribs 114 with larger height ribs and smaller height ribs reduce coefficient of friction between the sheath 112 and a duct. The varying height of ribs reduces a number of contact points as compared to a design where all ribs are of same height. The varying height reduces surface area in contact with inner diameter of duct which helps in lowering coefficient of friction. In addition, larger and irregular surface area of the optical fiber cable 100 increases drag force which helps in blowing.
[0030] A number of the first type of ribs may be equal to the number of second type of ribs. The first type of ribs and the second type of ribs are arranged alternately to each other. The alternate arrangement of the first type of ribs and the second type of ribs enables reduction in weight of the optical fiber cable 100. The varying height of the ribs reduces the weight of the optical fiber cable 100 as compared to a cable with ribs with equal height. In addition, the alternate arrangement of the first type of ribs and the second type of ribs reduces friction in the optical fiber cable 100. A number of the first type of ribs may be 6 (as shown in FIG. 1). A number of the first type of ribs may vary. A number of the second type of ribs may be 6. A number of the second type of ribs may vary.
[0031] A number of the plurality of ribs 114 (the first type of ribs and the second type of ribs) may be 12 (as shown in FIG. 1). A number of the plurality of ribs 114 (the first type of ribs and the second type of ribs) may be 20 (as shown in FIG. 2). A number of the plurality of ribs 114 (the first type of ribs and the second type of ribs) may be in a range of 4-24. In a case, where the number of ribs is below 4, symmetry cannot be achieved with two different heights of ribs. Similarly, for a cable with 13mm outer diameter, more than 24 ribs will lead to very thin ribs and compromise bend performance. A number of the plurality of ribs 114 may vary. A number of the plurality of grooves 116 in the optical fiber cable 100 may be 12 (as shown in FIG. 1). A number of the plurality of grooves 116 in the optical fiber cable 100 may be 20 (as shown in FIG. 2). A number of the plurality of grooves 116 may be in a range of 4-24. A number of the plurality of grooves 116 may vary. The plurality of ribs 114 and the plurality of grooves 116 of the optical fiber cable 100 are arranged alternately to each other on the outer surface of the sheath 112.
[0032] The plurality of ribs 114 has at least two different heights and can be continuous or discontinuous. In other words, the plurality of ribs is continuous on entire length of the sheath 112 or the plurality of ribs is not continuous on the entire length of the sheath. The discontinuous ribs as shown in FIG. 4 may further reduce the number of contact points of the cable sheath with duct, hence reducing coefficient of friction and enhancing blowing performance. The height of the plurality of ribs 114 may preferably be in a range of 0.15 millimeter to 0.5 millimeters. The height of the plurality of ribs if below 0.15 millimeter are not feasible for manufacturing and if the height of the plurality of ribs is beyond 0.5 millimeters, the sheath will become weak as lots of material will be removed. The height of the first type of ribs (i.e., first height) of the optical fiber cable 100 may be 0.25 millimeter. In addition, the height of the second type of ribs (i.e., second height) of the optical fiber cable 100 is 0.15 millimeter. The height of the first type of ribs and the second type of ribs of the optical fiber cable 100 may vary. The plurality of ribs 114 may have a width of 1.63 millimeter. The plurality of grooves 116 may have a width of 1.63 millimeter. However, the width of the plurality of ribs 114 and the plurality of grooves 116 may vary based on diameter of the optical fiber cable 100. The plurality of ribs 114 may be, but not limited to, rectangular shaped, triangular shaped, arc-shaped, trapezoidal shaped.
[0033] The alternate arrangement of the first type of ribs and the second type of ribs enables high crushing performance. The crushing performance is a compressive loading resistance of the optical fiber cable. In addition, the first type of ribs supports the second type of ribs when a fixed crush load is applied on the optical fiber cable 100 that enables high crushing performance as compared to the similar design of cable where all the ribs having equal height. The high crushing performance is seen when number of the plurality of ribs 114 is equivalent to twice of an odd number.
[0034] The optical fiber cable 100 may be installed into the duct using a blowing process. In addition, the optical fiber cable 100 is concentrically arranged inside the duct. Further, the sheath 112 is concentric with the duct. Furthermore, the duct surrounds the optical fiber cable 100. Moreover, the blowing process to install the optical fiber cable 100 in the duct is dependent on a plurality of factors. The plurality of factors includes mass of the optical fiber cable 100, friction between the optical fiber cable 100 and the duct, stiffness of the optical fiber cable 100, and the like. Also, the blowing process enables installation of the optical fiber cable 100 using pressurized air combined with a mechanical pushing force.
[0035] Further, the optical fiber cable 100 includes the plurality of strength members 118. Each of the plurality of strength members 118 is embedded in the sheath 112 and extends along a length of the sheath 112. The plurality of strength members 118 is embedded in the sheath 112 to provide the required mechanical strength and stiffness to the optical fiber cable 100. Since, the optical fiber cable 100 does not have a central strength member, the needed mechanical properties come from the sheath with the plurality of strength members 118. The plurality of strength members 118 improves the cable stiffness that enhances the blowing capacity of the cable and provides physical strength to the cable for handling and crush/kink protection.
[0036] The plurality of strength members 118 is positioned below the plurality of ribs 114 or may partially overlap the plurality of ribs 114 (as shown in FIG. 5). In an implementation, number of the plurality of strength members 118 embedded in the sheath 112 can be equal or less than number of the plurality of ribs 114. The plurality of strength members 118 may be embedded below each of the plurality of ribs 114 as shown in FIG. 1. Alternatively, the plurality of strength members 118 may be embedded below larger ribs only as shown in FIG. 2 or below smaller ribs only as shown in FIG. 3. The plurality of strength members 118 enhances blowing performance of the optical fiber cable 100 by increasing stiffness of the optical fiber cable 100. Moreover, the plurality of strength members 118 provides tensile strength to the optical fiber cable 100. Also, the plurality of strength members 118 enhances resistance against crush.
[0037] Each of the plurality of strength members 118 is embedded at radially equidistance from a geometric center of the optical fiber cable 100. This arrangement ensures symmetric stiffness in the optical fiber cable 100 that is a required parameter for good blowing of the cable. Further, each of the plurality of strength members 118 is embedded at equal angular distance from each other in the sheath 112. This arrangement also ensures symmetric stiffness in the optical fiber cable 100-.
[0038] The plurality of strength members 118 is uniformly distributed in the sheath 112. The uniform distribution ensures uniform stiffness which helps in increasing blowing performance. Each of the plurality of strength members 118 is an Aramid Reinforcement Plastic (ARP) rod or Fiber Reinforcement Plastic (FRP) rod or any other suitable strength member. In addition, the plurality of strength members 118 may be coated with EAA (Ethylene acrylic acid). The EAA coating melts during extrusion and bonds the plurality of strength members 118 firmly with material of the sheath 112. This leads to better grip of ARP strength members in the sheath 112 and thus improved stiffness. Also, this is easy to process during manufacturing as compared to uncoated ARP since the uncoated ARP has dust accumulation problems which lead to sheath loss in manufacturing. A number of the plurality of strength members 118 embedded in the sheath 112 of the optical fiber cable 100 is 12 (as shown in FIG. 1). A number of the plurality of strength members 118 embedded in the sheath 112 of the optical fiber cable 100 is 10 (as shown in FIG. 2). A number of the plurality of strength members 118 may vary. The plurality of strength members 118 may be placed below larger ribs (as shown in FIG. 2) or smaller ribs (as shown in FIG. 3). The plurality of strength members 118 is placed below the plurality of ribs 114 that helps in preventing the plurality of strength members 118 from coming out of the sheath 112 while bending or handling the optical fiber cable 100.
[0039] The plurality of strength members 118 is chosen with a diameter less than the width of the plurality of ribs 114 at bottom of the plurality of ribs 114, so that the plurality of strength members 118 can be placed below the plurality of ribs 114. This arrangement ensures that there is enough material available above the plurality of strength members 118 that maintains structural integrity of the sheath 112 and prevents ripping of the sheath 112 by the plurality of strength members 118 during handling.
[0040] Further, the optical fiber cable 100 may include one or more ripcords 120. The one or more ripcords 120 is positioned outside the water blocking tape 110. In general, ripcords are used for stripping of sheath of optical fiber cable. The one or more ripcords 120 facilitates access to the plurality of optical fibers. The one or more ripcords 120 may lie diametrically opposite to each other. Each of the one or more ripcords 120 may have a circular shape. The one or more ripcords 120 may have any suitable shape. A number of the ripcords 120 inside the optical fiber cable 100 is two. A number of the ripcords 120 inside the optical fiber cable 100 may vary.
[0041] The optical fiber cable 100 may have a suitable value of deformation of under crushing load. In addition, the deformation of the optical fiber cable 100 may vary depending upon the plurality of parameters. The plurality of parameters includes but may not be limited to number of the plurality of ribs 114 and number of the plurality of grooves 116, width and height of the plurality of ribs 114 and the plurality of grooves 116, inside and outside diameter of the optical fiber cable 100, number of the plurality of strength members 118 in the sheath 112, and material grade of the optical fiber cable 100. The optical fiber cable 100 with 432 optical fibers may have an inner diameter in a range of 8.4 millimeters to 9.2 millimeters. The inner diameter varies based upon fiber count of the optical fiber cable 100. The optical fiber cable 100 with 432 optical fibers may have an outer diameter in a range of 11 millimeters to 13 millimeters. The outer diameter varies based upon fiber count of the optical fiber cable 100.
[0042] The combination of features for 432 fiber count optical fiber cable including EAA coated ARP, positioning of ARPs below ribs, 10 ARPs with 20 ribs enables blowing of more than 1100 meters in a duct with inner diameter of 14 millimeters and outer diameter of 18 millimeters. The duct is laid as per IEC standards.
[0043] It will be apparent to those skilled in the art that other alternatives of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention. While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific aspect, method, and examples herein. The invention should therefore not be limited by the above described alternative, method, and examples, but by all aspects and methods within the scope of the invention. It is intended that the specification and examples be considered as exemplary, with the true scope of the invention being indicated by the claims.
[0044] Conditional language used herein, such as, among others, "can," "may," "might," "may," “e.g.,” and the like, unless specifically stated otherwise, or otherwise understood within the context as used, is generally intended to convey that certain alternatives include, while other alternatives do not include, certain features, elements and/or steps. Thus, such conditional language is not generally intended to imply that features, elements and/or steps are in any way required for one or more alternatives or that one or more alternatives necessarily include logic for deciding, with or without other input or prompting, whether these features, elements and/or steps are included or are to be performed in any particular alternative. The terms “comprising,” “including,” “having,” and the like are synonymous and are used inclusively, in an open-ended fashion, and do not exclude additional elements, features, acts, operations, and so forth. Also, the term “or” is used in its inclusive sense (and not in its exclusive sense) so that when used, for example, to connect a list of elements, the term “or” means one, some, or all of the elements in the list.
[0045] Disjunctive language such as the phrase “at least one of X, Y, Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and/or Z). Thus, such disjunctive language is not generally intended to, and should not, imply that certain alternatives require at least one of X, at least one of Y, or at least one of Z to each be present.
[0046] While the detailed description has shown, described, and pointed out novel features as applied to various alternatives, it can be understood that various omissions, substitutions, and changes in the form and details of the devices or algorithms illustrated can be made without departing from the scope of the disclosure. As can be recognized, certain alternatives described herein can be embodied within a form that does not provide all of the features and benefits set forth herein, as some features can be used or practiced separately from others.

We Claim:

1.A corrugated sheath (112) for use in an optical fiber cable (100), the corrugated sheath (112) comprising:
a plurality of ribs (114) on an outer surface of the corrugated sheath (112), the plurality of ribs (114) is longitudinal protrusions on the outer surface of the corrugated sheath (112) and is parallel to an axis of the optical fiber cable (100), wherein the plurality of ribs (114) has at least two different heights; and
a plurality of strength members (118) embedded in the corrugated sheath (112) such that the plurality of strength members (118) is placed under the plurality of ribs (114).

2. The corrugated sheath (112) as claimed in claim 1, wherein the plurality of ribs (114) on the corrugated sheath (112) can be continuous or discontinuous.

3. The corrugated sheath (112) as claimed in claim 1, wherein the plurality of strength members (118) embedded in the corrugated sheath (112) has a diameter less than a width of the plurality of ribs (114) at bottom of the plurality of ribs (114).

4. The corrugated sheath (112) as claimed in claim 1, wherein the plurality of strength members (118) embedded in the corrugated sheath (112) such that the plurality of strength members is radially equidistant from a geometric center of the optical fiber cable (100).

5. The corrugated sheath (112) as claimed in claim 1, wherein the plurality of strength members (118) embedded in the corrugated sheath (112) such that each of the plurality of strength members (118) is spaced apart at equal angular distance in the corrugated sheath (112).

6. The corrugated sheath (112) as claimed in claim 1, wherein number of the plurality of strength members (118) embedded in the corrugated sheath (112) can be equal or less than number of the plurality of ribs (114).

7. The corrugated sheath (112) as claimed in claim 1, wherein the plurality of strength members (118) is positioned below the plurality of ribs (114) or may partially overlap the plurality of ribs (114).

8. The corrugated sheath (112) as claimed in claim 1, wherein the plurality of ribs (114) includes a first type of ribs (114a) and a second type of ribs (114b), where number of the first type of ribs (114a) and number of the second type of ribs (114b) are equal and the first type of ribs and the second type of ribs are arranged alternately to each other.

9. A corrugated sheath (112) for use in an optical fiber cable (100), the corrugated sheath (112) comprising:
a plurality of ribs (114) on an outer surface of the corrugated sheath (112), the plurality of ribs (114) is longitudinal protrusions on the outer surface of the corrugated sheath (112) and is parallel to an axis of the optical fiber cable (100), wherein the plurality of ribs (114) is discontinuous.

10. The corrugated sheath (112) as claimed in claim 9, wherein the plurality of ribs (114) has at least two different heights.

11. The corrugated sheath (112) as claimed in claim 9, wherein the plurality of strength members (118) embedded in the corrugated sheath (112) has a diameter less than a width of the plurality of ribs (114) at bottom of the plurality of ribs (114).

12. The corrugated sheath (112) as claimed in claim 9, wherein the plurality of ribs (114) includes a first type of ribs (114a) and a second type of ribs (114b), where number of the first type of ribs (114a) and number of the second type of ribs (114b) are equal and the first type of ribs and the second type of ribs are arranged alternately to each other.