Modular nested butterfly cable

Abstract

This application relates to a modular nested butterfly optical cable, belonging to the field of optical communication transmission technology. It includes at least one first butterfly optical cable sub-unit, which comprises: a sheath containing optical fiber units and reinforcing members; a docking structure including a male and a female docking end on the sheath, the male docking end being used to dock with the female docking end of another first butterfly optical cable sub-unit; and a stripping guide on the sheath, used to separate the male docking end docked to the female docking end from the female docking end. The docking structure on the sheath sidewall enables the detachable and interlocking combination of multiple butterfly optical cable sub-units, while the stripping guide at the bottom of the sheath guides the butterfly optical cable sub-units to separate from the whole. This design has the advantages of compact structure, flexible expansion, easy branching and maintenance, permanent fiber core identification, and seamless transition between outdoor and indoor materials, meeting the urgent needs of high-density and flexible deployment in future access networks.

Description

Technical Field

[0001] This application relates to the field of optical communication transmission technology, and in particular to a modular nested butterfly optical cable. Background Technology

[0002] Butterfly-shaped optical cables are characterized by low cost, easy bending, and convenient construction, making them a key drop cable for efficient and economical deployment of Fiber to the Home (FTTH). When multi-core transmission is required, multi-core integrated butterfly-shaped optical cables are typically used. This involves arranging multiple optical fibers in parallel, encasing them in a uniform sheath, and adding reinforcing members on both sides or in the middle of the sheath for tensile support. This structure is manufactured through a single extrusion molding process, fixing all optical fibers within the same sheath to form an inseparable, integrated structure.

[0003] However, as access networks develop towards high-density, multi-operator coexistence, and old-age upgrades, traditional butterfly-shaped optical cables are revealing increasingly prominent systemic problems in multi-core application scenarios.

[0004] First, multi-core applications suffer from significant material waste, with costs increasing non-linearly with the number of cores. When 2, 4, or even more cores are needed, traditional solutions offer two options: one is to lay multiple independent butterfly cables simultaneously, resulting in messy and tangled cables within the conduit; the other is to use an integrated extruded multi-core butterfly cable, wrapping multiple optical fibers and reinforcements in a large sheath. The latter has a large amount of redundant filling area within the sheath. Taking a 2-core butterfly cable as an example, its sheath cross-sectional area is much larger than the sum of the areas of two single-core butterfly cables, resulting in low material utilization and a sharp increase in cost per core as the number of cores increases.

[0005] Secondly, traditional multi-core cables have a fixed capacity at the factory. If additional fiber cores are needed later, re-insertion into conduits or destructive construction is required. In the renovation of old residential areas, conduit resources are already scarce, and secondary conduit installation is not only costly but may also damage existing walls and floors. Furthermore, there are significant drawbacks in branch operation and maintenance. Branching requires cutting the outer sheath and performing fiber optic splicing, which not only relies on specialized equipment such as fusion splicers and professional personnel, but is also cumbersome and time-consuming. Additional losses introduced at the splice points also affect network quality. Additionally, it is difficult to replace a single faulty fiber individually. Cutting the entire cable or damaging the conduit will cause service interruptions for other users, resulting in high maintenance costs and a high likelihood of user complaints. Summary of the Invention

[0006] This application provides a modular nested butterfly optical cable to solve the problems of messy wiring, poor expansion flexibility, complex branching operations, and difficult maintenance in the construction and application scenarios of traditional butterfly optical cables in related technologies.

[0007] In a first aspect, a modular nested butterfly optical cable is provided, comprising: at least one first butterfly optical cable subunit, the first butterfly optical cable subunit comprising: a sheath having an internal optical fiber unit and a reinforcing member; a docking structure comprising a male docking end and a female docking end disposed on the sheath, the male docking end being used to dock with the female docking end of another first butterfly optical cable subunit; and a stripping guide disposed on the sheath and used to separate the male docking end docked to the female docking end from the female docking end.

[0008] In some embodiments, the butterfly optical cable further includes a second butterfly optical cable subunit, which includes: a sheath having an internal optical fiber unit and a reinforcing member; and a male connector disposed on the sheath.

[0009] In some embodiments, the butterfly optical cable further includes a third butterfly optical cable subunit, which includes: a sheath containing an optical fiber unit and a reinforcing member; a female connector disposed on the sheath; and a stripping guide disposed on the sheath for separating the male connector connected to the female connector from the female connector. In some embodiments, In some embodiments, the male end of the docking device includes a guide protrusion, and the female end of the docking device includes a guide groove.

[0010] In some embodiments, the groove width of the guide groove is smaller than the maximum width of the guide protrusion.

[0011] In some embodiments, the bottom of the sheath extends along the length direction and is provided with a guide groove, the bottom of the guide groove is formed with an angle, and the peeling guide is formed at the angle at the bottom of the guide groove.

[0012] In some embodiments, the reinforcement comprises steel wire and / or glass fiber reinforced plastic rods.

[0013] In some embodiments, the reinforcement further includes a power line, and in at least one of the plurality of first butterfly-shaped optical cable subunits, the reinforcement is configured as a power line.

[0014] In some embodiments, at least two of the plurality of first butterfly optical cable sub-units have different sheath materials.

[0015] In some embodiments, the surface of the sheath is provided with a visual identification mark.

[0016] The beneficial effects of the technical solution provided in this application include: Employing a single reinforcing member, a first butterfly-shaped optical cable sub-unit, and a docking structure, this design overcomes the limitations of traditional butterfly cables with dual reinforcing members and symmetrical designs. Each sub-unit has a compact cross-section, and multiple sub-units share a common sidewall, eliminating sheath redundancy and reducing the cross-sectional area per core, significantly lowering raw material costs. Furthermore, manufacturing requires only one set of molds, and two units can be assembled and produced using nested meshing tooling. This 12-core product series enables "single-specification production and multi-specification delivery," reducing mold and inventory costs. During use, the stripping guide allows for tool-free manual tearing of ion units, shortening branching and on-site termination time and improving construction efficiency. During maintenance, faulty sub-units can be individually removed, ensuring zero interruption of other fiber optic signals on the backbone. For expansion, the existing sub-unit docking structure serves as a guide rail, allowing for smooth expansion without secondary conduit insertion. Each sub-unit has a visually identifiable and permanently recognizable label. It supports nested combinations of various sheath materials, offering outdoor weather resistance and indoor flame retardancy without the need for fusion splicing. The bending radius is comparable to that of single-core butterfly cables, simplifying wiring. The reinforcing element can be replaced with a power line to achieve optoelectronic composite functionality. This invention comprehensively optimizes the performance and economy of multi-core butterfly cables from structure to construction, maintenance, and expansion. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of this application; Figure 2 The structural schematic diagram provided in this application illustrates the second and third butterfly-shaped optical cable subunits. Figure 3 This is a schematic diagram illustrating nested meshing tooling provided for embodiments of this application.

[0019] In the figure: 10, First butterfly-shaped optical cable sub-unit; 11, Second butterfly-shaped optical cable sub-unit; 12, Third butterfly-shaped optical cable sub-unit; 2, Optical fiber unit; 3, Reinforcing member; 4, Sheath; 5, Connecting structure; 50, Male connector; 51, Female connector; 6, Stripping guide; 7, Nested meshing fixture. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] This application provides a modular nested butterfly optical cable, which can solve the problems of messy wiring, poor expansion flexibility, complex branching operations and difficult maintenance in the construction and application scenarios of traditional butterfly optical cables in related technologies.

[0022] Reference Figure 1-3 A modular nested butterfly optical cable includes: at least one first butterfly optical cable sub-unit 10, the first butterfly optical cable sub-unit 10 including: a sheath 4, a docking structure 5, and a stripping guide 6. The sheath 4 is provided with an optical fiber unit 2 and a reinforcing member 3 inside, and the reinforcing member 3 is arranged parallel to one side of the optical fiber unit 2; the docking structure 5 includes a docking male end 50 and a docking female end 51 provided on the sheath 4. The docking male end 50 is used to dock with the docking female end 51 of another first butterfly optical cable sub-unit 10, so that multiple first butterfly optical cable sub-units 10 can be interlocked through the docking structures 5 on adjacent sheaths 4 and combined side by side in the width direction to form a whole. In the combined optical cable, two adjacent first butterfly optical cable sub-units 10 share a sidewall interface, and each first butterfly optical cable sub-unit 10 independently includes a reinforcing member 3; the stripping guide 6 is provided on the sheath 4 and is used to separate the docking male end 50 docked on the docking female end 51 from the docking female end 51.

[0023] In this application, optical fiber unit 2 and single reinforcing member 3 are laid out in parallel, and then an outer sheath 4 is wrapped around them using an extruder to form a first butterfly-shaped optical cable subunit 10. The first butterfly-shaped optical cable subunit 10 after forming has a flat cross-section with a width of 3.0-4.0 mm and a thickness of 2.0±0.1 mm. After the first butterfly-shaped optical cable subunit 10 is prepared, it is wound into an independent coil for later use.

[0024] By setting up a first butterfly-shaped optical cable sub-unit 10, which independently contains optical fiber units 2 and reinforcing members 3, and utilizing the docking male end 50 and docking female end 51 structure on the sheath 4, multiple sub-units are interlocked along the width direction and adjacent sub-units share the sidewall interface, thereby forming an integral optical cable. With the help of the stripping guide 6 on the sheath 4, the docking male end 50 is separated from the docking female end 51, forming an integral optical cable that can be flexibly combined. This design achieves miniaturization and reduces manufacturing costs through the sidewall nesting structure. It also enables convenient separation between sub-units with the help of the stripping guide 6, so that subsequent capacity expansion does not require destructive construction, branching operations do not require professional fusion splicing, and single-core failures can be independently removed and replaced without interrupting other signal transmissions. This effectively solves the technical problems of traditional butterfly-shaped optical cables in multi-core application scenarios, such as structural redundancy, poor capacity expansion flexibility, complex branching operations, and difficult independent maintenance.

[0025] In this application, the male connector 50 includes a guide protrusion, and the female connector includes a guide groove. The width of the guide groove opening is less than the maximum width of the guide protrusion, preferably one of a dovetail, T-shape, or wedge shape. The male connector 50 is designated as a guide protrusion, and the female connector 51 as a guide groove. The guide protrusion and guide groove are arranged on opposite side walls of the sheath 4, and the width of the guide groove opening is strictly controlled to be less than the maximum width of the guide protrusion, preferably a dovetail, T-shape, or wedge structure. This geometric locking principle achieves mechanical interlocking and interference fit between the first butterfly-shaped optical cable sub-units 10, significantly enhancing the structural integrity and connection stability of the combined multiple sub-units of the first butterfly-shaped optical cable. This prevents the optical cable from accidentally loosening and separating during laying traction or under lateral external force. Simultaneously, this specific guiding and locking shape, combined with the stripping guide 6, provides a clear separation path and force point when maintenance or expansion is required, enabling the first butterfly-shaped optical cable sub-unit 10 to be controllably separated and pulled out without damaging the sheath 4.

[0026] Specifically: Based on the required number of cores, such as 2 cores, 4 cores, or 8 cores, the corresponding number of first butterfly-shaped optical cable sub-units 10 are simultaneously unloaded from the reels. Each first butterfly-shaped optical cable sub-unit 10 enters the nesting engagement fixture 7 side-by-side. The nesting engagement fixture 7 has a guide channel whose cross-section gradually tightens along the travel direction of the first butterfly-shaped optical cable sub-units 10. The width of the inlet end matches the total width of the multiple first butterfly-shaped optical cable sub-units 10, and the width of the outlet end matches the width of the combined multi-core cable. After entering the fixture, the first butterfly-shaped optical cable sub-units 10 are compressed, and the guide protrusions on the sidewalls interlock with the guide grooves of adjacent first butterfly-shaped optical cable sub-units 10 to form a multi-unit combined cable. The fixture structure is similar to a zipper; the first butterfly-shaped optical cable sub-units 10 automatically engage to form a multi-unit butterfly cable upon entry. The combined multi-unit cable is then wound into the finished reel manually or automatically. During winding, the tension of each sub-unit is kept uniform to ensure the stability of the combined structure.

[0027] In this application, the designed butterfly-shaped optical cable also includes a second butterfly-shaped optical cable subunit 11. The second butterfly-shaped optical cable subunit 11 includes a sheath 4 and a male connector 50. The sheath 4 contains an optical fiber unit 2 and a reinforcing member 3, with the reinforcing member 3 arranged parallel to one side of the optical fiber unit 2. The male connector 50 is located on the sheath 4 and includes a guide protrusion. In specific installation scenarios, depending on the usage, the second butterfly-shaped optical cable subunit 11 can be connected to the very end of the optical cable during installation, and the guide protrusion connects to the guide groove on the sheath 4 of the previous first butterfly-shaped optical cable subunit 10. By adding a second butterfly-shaped optical cable sub-unit 11, which also contains an optical fiber unit 2 and a reinforcing member 3, and setting a male connector 50 on its sheath 4, it can be flexibly connected to the end of the optical cable assembly according to actual installation requirements. This not only maintains the consistency of the overall transmission performance and mechanical strength of the optical cable and ensures that the end part has independent tensile support to avoid damage to the end, but also provides flexible end expansion and adaptation capabilities. It allows the structural size to be adjusted or adapted to specific terminal interfaces by adding the second butterfly-shaped optical cable sub-unit 11 without replacing the trunk cable. This effectively improves the adaptability of the optical cable in different laying scenarios, the convenience of end processing, and the flexibility of network deployment, and meets the precise length matching and end protection requirements in diverse scenarios. In this application, the butterfly optical cable also includes a third butterfly optical cable sub-unit 12. The third butterfly optical cable sub-unit 12 includes: a sheath 4, a female connector 51, and a stripping guide 6. The sheath 4 is provided with an optical fiber unit 2 and a reinforcing member 3 inside. The reinforcing member 3 is arranged parallel to one side of the optical fiber unit 2. The female connector 51 is provided on the sheath 4 and includes a guide groove. The stripping guide 6 is provided on the sheath 4 and is used to separate the male connector 50 connected to the female connector 51 from the female connector 51.

[0028] In specific installation scenarios, depending on the usage, the third butterfly-shaped optical cable subunit 12 can be connected to the front end of the optical cable during installation. The third butterfly-shaped optical cable subunit 12 has an independent optical fiber unit 2 and a reinforcing member 3 inside to ensure the independent transmission performance and structural strength of the front end. The sheath 4 is provided with a docking female end 51 containing a guide groove to achieve a stable fitting connection with the rear cable unit. In particular, a stripping guide part 6 is configured at the leading edge position to separate the docking male end 50 docked with the docking female end 51 from the docking female end 51. This is to modularize and functionalize the optical cable's entry end. The independent reinforcing member 3 ensures the structural strength of the optical cable's front end during the laying and pulling process, and ensures the mechanical performance of the optical cable under overhead / lateral pressure conditions. Furthermore, the front-end stripping guide 6 enables convenient and non-destructive disassembly at the optical cable entry point, allowing for quick separation of the front-end unit without cutting the main cable sheath 4 when working at user access points or branch points. This effectively improves the flexibility of optical cable front-end processing, construction efficiency, and ease of subsequent maintenance, meeting the dual requirements of optical cable end independence and ease of operation in specific installation scenarios.

[0029] In this application, a guide groove is provided extending along the length of the bottom of the sheath 4, with an angle formed at the bottom of the guide groove. The stripping guide 6 is formed at the angle at the bottom of the guide groove. By utilizing the geometric stress concentration characteristics of the angle and the path restriction effect of the guide groove, a precise force point and trajectory are provided for stripping, significantly reducing the difficulty of the stripping operation and ensuring that the separation process is strictly carried out along the predetermined path. This effectively avoids damage to the internal fiber unit 2 or the reinforcing member 3 due to operational deviations, while improving the efficiency and consistency of sub-unit separation. It achieves rapid, non-destructive, and precise modular disassembly, thereby greatly improving the convenience of construction and maintenance while ensuring the structural integrity of the optical cable.

[0030] When a subunit malfunctions and needs replacement, the operating steps are as follows: First, at the duct inlet, peel the faulty first butterfly-shaped optical cable subunit 10 from the assembly. No tools are needed; simply tear it off by hand along the guide groove. Second, at the duct outlet, use pliers to clamp the end of the faulty first butterfly-shaped optical cable subunit 10 and gently pull it out of the duct as a whole, leaving the remaining first butterfly-shaped optical cable subunits 10 in place. Third, slide the new first butterfly-shaped optical cable subunit 10 into the duct along the guide groove of the existing first butterfly-shaped optical cable subunit 10 and push it to the outlet. Fourth, the new first butterfly-shaped optical cable subunit 10 automatically engages with the original first butterfly-shaped optical cable subunit 10 through the guide protrusion and guide groove, restoring the assembly state. The entire removal and replacement process does not damage the duct or wall and does not affect the fiber optic transmission of other lines. The replacement principles for the second butterfly-shaped optical cable subunit 11 and the third butterfly-shaped optical cable subunit 12 are the same and will not be described further here.

[0031] During the initial installation, the first set of first butterfly-shaped optical cable sub-units 10 are inserted into the pipe; when expansion is required later, the guide groove on the side wall of the already laid first butterfly-shaped optical cable sub-units 10 is used as a slide rail to push the new first butterfly-shaped optical cable sub-units 10 from the pipe inlet end, so that it slides along the slide rail to the destination and is fitted and combined with the original first butterfly-shaped optical cable sub-units 10. For example, in a newly built residential community with an initial occupancy rate of 30%, only three first butterfly-shaped optical cable sub-units 10 are laid, covering 30% of users. Space is reserved within the conduit, saving 70% on initial investment. One year later, when the occupancy rate rises to 60% and three more households need to be added, the guide grooves on the sides of the existing first butterfly-shaped optical cable sub-units 10 are used as slide rails to push the three new first butterfly-shaped optical cable sub-units 10 sequentially into the conduit. The new first butterfly-shaped optical cable sub-units 10 automatically slide along the slide rails to their destination and engage with the existing first butterfly-shaped optical cable sub-units 10. The entire expansion process requires no re-threading of conduits and no damage to existing fixtures; expansion per household takes approximately 5 minutes. The replacement principles for the second butterfly-shaped optical cable sub-unit 11 and the third butterfly-shaped optical cable sub-unit 12 are the same and will not be elaborated upon here.

[0032] In this application, the designed reinforcing member 3 includes a steel wire and / or glass fiber reinforced plastic rod. Steel wire, glass fiber, or a combination of both are selected as the reinforcing member 3. The high tensile strength and excellent mechanical properties of the reinforcing plastic rod contribute to the mechanical properties of each individual subunit.

[0033] In this application, the reinforcing member 3 also includes a power line. Among the multiple first butterfly-shaped optical cable sub-units 10, at least one reinforcing member 3 is set as a power line. When at least one reinforcing member 3 is used as a power line, the first butterfly-shaped optical cable sub-unit 10 can also have power transmission function. Optoelectronic composite cable is realized without changing the overall structure. It is suitable for scenarios that require remote power supply, such as 5G small base stations and IoT sensors, and eliminates the cost of laying additional power lines.

[0034] In this application, at least two of the multiple first butterfly-shaped optical cable sub-units 10 have different sheath 4 materials. The sheath 4 material includes low-smoke halogen-free flame-retardant polyolefin, glass fiber reinforced plastic, polyvinyl chloride, or polyethylene. Low-smoke halogen-free flame-retardant polyolefin is used for indoor flame-retardant applications, polyvinyl chloride for general indoor applications, and polyethylene for outdoor overhead applications. When at least one first butterfly-shaped optical cable sub-unit 10 has a sheath 4 material of polyethylene for an outdoor overhead backbone section, and at least another first butterfly-shaped optical cable sub-unit 10 has a sheath 4 material of low-smoke halogen-free flame-retardant polyolefin or polyvinyl chloride for an indoor entry section, sub-units with different sheath 4 materials are nested and combined through a docking structure 5 to achieve a material transition from outdoor to indoor environments.

[0035] This application describes the specific application scenario as follows: First, the basic first butterfly-shaped optical cable subunit 10, applicable to fiber-to-the-home scenarios, specifically includes: optical fiber unit 2, reinforcing member 3, sheath 4, docking structure 5, and stripping guide 6; the optical fiber unit 2 is a single G.657.A2 bend-insensitive optical fiber, positioned slightly off-center from the center of the first butterfly-shaped optical cable subunit 10; the reinforcing member 3 is a single glass fiber reinforced plastic with a diameter of 0.50±0.02 mm, positioned parallel to one side of the optical fiber unit 2, with a center distance of 1.2 mm from the optical fiber unit 2; the sheath 4 is made of low-smoke halogen-free flame-retardant polyolefin material, formed by extrusion, with a flat cross-section, a width of 3.0±0.1 mm, and a thickness of 2.0±0.1 mm; the low-smoke halogen-free flame-retardant polyolefin material produces low smoke and releases no halogens when exposed to fire, making it suitable for scenarios with high indoor flame-retardant requirements; the sheath 4 has a guide protrusion on the left side and a guide groove on the right side, with a guide protrusion height of 0.8 mm and a guide groove depth of 0.8 mm. mm; a guide groove is set at the center of the bottom of the sheath 4, with a groove depth of 0.3 mm and a groove angle of 60°, extending along the entire length of the first butterfly-shaped optical cable sub-unit 10, for on-site stripping guidance. The manufacturing process involves laying the optical fiber unit and the reinforcing member in parallel, and then covering the sheath with an extruder. The extrusion temperature is controlled at 160-180℃, and the mold design forms guide protrusions and guide grooves on the side walls and a guide groove on the bottom. After forming, it is water-cooled for shaping and wound into an independent coil. The diameter of the coil is determined according to the length of the first butterfly-shaped optical cable sub-unit 10.

[0036] Secondly, it is suitable for outdoor overhead section scenarios. The difference between it and fiber-to-the-home scenarios is that the sheath 4 material is made of polyethylene, which has good waterproof, UV resistance, weather resistance and long service life, and is suitable for outdoor overhead or pipeline laying scenarios; sheath 4 dimensions: width 3.2±0.1 mm, thickness 2.1±0.1 mm; extrusion temperature: 180-220℃.

[0037] Third, it is suitable for ordinary indoor scenarios, specifically including: fiber optic unit 2, reinforcing member 3, sheath 4, docking structure 5, and stripping guide 6; the fiber optic unit 2 consists of two parallel G.657.A2 optical fibers with a spacing of 0.5 mm, located on one side of the center of the first butterfly-shaped optical cable subunit 10; the reinforcing member 3 is a steel wire with a diameter of 0.60±0.02 mm, located on one side of the two fiber optic units to provide tensile support; the sheath 4 is made of polyvinyl chloride, which is economical and suitable for ordinary indoor scenarios; the sheath 4 has a width of 4.0±0.1 mm and a thickness of 2.0±0.1 mm; the sheath 4 has a guide ridge on the left side and a guide groove on the right side, with a guide ridge height of 0.8 mm and a guide ridge groove depth of 0.8 mm; the sheath 4 has a guide groove at the center of the bottom, with a groove depth of 0.3 mm and a groove angle of 60°, extending along the entire length of the first butterfly-shaped optical cable subunit 10 for on-site stripping guidance.

[0038] Fourth, a 2-core modular combined butterfly optical cable is assembled using a nested meshing fixture 7. Specifically, it includes a 2-core butterfly optical cable composed of two basic first butterfly optical cable sub-units 10 suitable for fiber-to-the-home scenarios. The assembly process involves simultaneously releasing the two first butterfly optical cable sub-units 10 onto their reels, and then inserting them side-by-side into the nested meshing fixture 7. The width of the fixture's inlet end is approximately 6.2 mm, slightly larger than the total width of the two sub-units, and the width of its outlet end is approximately 5.8 mm, representing the total width after assembly. As the two first butterfly optical cable sub-units 10 move forward, the fixture's cross-section gradually tightens. Under the pressure, the guide groove on the right side of one first butterfly optical cable sub-unit 10 automatically engages with the guide protrusion on the left side of the other first butterfly optical cable sub-unit 10. The assembled structure consists of two first butterfly optical cable sub-units 10 sharing a common sidewall interface, with an overall width of approximately 5.8 mm and a thickness of 2.0 mm. The assembled 2-core cable is wound onto a finished reel manually or automatically, with the winding tension controlled at 30-50 N to ensure a tight assembly. The assembled optical cable has a tensile strength ≥400 N and a bending radius ≤15 mm, comparable to a single-core butterfly cable.

[0039] Fifth, the all-scenario through-type optical cable, which uses a nested structure of multiple materials, adopts a nested combination of sub-units with different sheaths 4 to achieve a seamless transition from outdoor to indoor use. Specifically, the optical cable is composed of four nested first butterfly-shaped optical cable sub-units 10, which are divided into two categories according to the usage section: sub-unit A and sub-unit B, both with sheaths 4 made of polyethylene, used in outdoor overhead trunk sections, with the functional characteristics of weather resistance, UV resistance, waterproofing, and a lifespan of ≥20 years; sub-units C and D, with the sheaths 4 of sub-units made of low-smoke halogen-free flame-retardant polyolefin material, and the sheaths 4 of sub-unit D made of polyvinyl chloride, both used in indoor entry sections. Sub-unit C is characterized by flame retardancy, low smoke, and safety, and is suitable for indoor use, while sub-unit D is characterized by economy and is suitable for ordinary indoor scenarios.

[0040] Assembly method: Four first butterfly-shaped optical cable sub-units 10 are arranged side by side into a whole through the nested docking structure of the side wall, wherein sub-unit A and sub-unit B are located on one side of the assembly, and sub-unit C and sub-unit D are located on the other side, forming a material partitioning structure. Laying and Branching Methods: Outdoor Overhead Section: The optical cable is laid in a combined state on outdoor overhead poles or in ducts. Sub-units A and B provide excellent weather resistance and UV resistance, ensuring long-term outdoor service life. Building Transition Section: Before the optical cable enters the building, sub-units C and D are manually stripped from the combined structure at the external terminal box, separating them from sub-units A and B. Indoor Entry Section: After stripping, sub-unit C continues to be laid along the building's vertical shaft and enters the resident's low-voltage electrical box. The low-smoke, halogen-free, flame-retardant polyolefin material releases no halogenated harmful substances when exposed to fire, ensuring the safety of the escape route. The stripped sub-unit D can be allocated to another resident. Polyvinyl chloride is economical and meets ordinary indoor flame-retardant requirements. Sub-units A and B remain combined and continue to be laid along the building's ducts to the roof or other outdoor sections for subsequent capacity expansion or coverage of other units. After the entry terminal units C and D reach the resident, they are stripped again into independent butterfly cables and directly inserted into the field connector for termination, without the need for fusion splicing.

[0041] In this application, a visual identification mark is also provided on the surface of the sheath 4. The visual identification mark preferably uses different colors and molded raised numerical marks on the surface of the sheath 4, or a combination of different colors and molded raised numerical marks on the surface of the sheath 4. Field branching requires no tools; the operation steps are as follows: First, at the branching location, identify the target sub-unit by color or numerical mark; second, along the guide groove at the bottom of the target sub-unit or the interlocking interface with the adjacent sub-unit, pinch it with your fingers and tear it outwards; third, the target sub-unit separates from the adjacent sub-unit along the interlocking interface, the stripping length determined as needed; fourth, the stripped sub-unit reverts to an independent butterfly-shaped optical cable form, which can be directly inserted into the field connector for termination and connection to terminal equipment. For example: at the location where entry is required, the target first butterfly-shaped optical cable sub-unit 10 is identified by color recognition, with the red first butterfly-shaped optical cable sub-unit 10 corresponding to household number 1; the bottom of the target first butterfly-shaped optical cable sub-unit 10 is pinched with fingers and torn outward along the guide groove; the target first butterfly-shaped optical cable sub-unit 10 separates from the adjacent first butterfly-shaped optical cable sub-unit 10 along the interlocking interface, with a stripping length of about 1.5 meters; after stripping, the first butterfly-shaped optical cable sub-unit 10 is restored to the shape of an independent butterfly-shaped optical cable, the end sheath 4 is stripped, the optical fiber is cleaned, and it is inserted into the field connector for termination; the entire branching operation takes about 30 seconds, and the termination takes about 2 minutes, totaling less than 3 minutes, without the need for any stripping tools.

[0042] The implementation principle of this application embodiment is as follows: by setting up first, second, and third butterfly-shaped optical cable sub-units 12, each with an independent internal optical fiber unit 2 and a reinforcing member 3, the structure of the male and female docking ends 50 and 51 provided on the sheath 4 allows multiple sub-units to be interlocked along the width direction and adjacent sub-units to share a sidewall interface to form an integral optical cable. The stripping guide 6 located at the corner of the guide groove at the bottom of the sheath 4 separates the docking ends. This structure not only eliminates the redundant filling area in the traditional integrated extruded multi-core cable sheath 4, significantly improving material utilization, but also achieves physical independence and mechanical locking between sub-units. This makes it possible to expand capacity without re-insertion or destructive construction, and branch operations without cutting the outer sheath 4 or splicing. In the event of a single optical fiber failure, the faulty sub-unit can be independently pulled out and replaced using the stripping guide 6 without interrupting other services. This effectively solves the systemic problems of messy wiring, poor capacity expansion flexibility, complex branch operations, and difficult maintenance of traditional butterfly-shaped optical cables in multi-core application scenarios.

[0043] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0044] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0045] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A modular nested butterfly optical cable, characterized in that, It includes: At least one first butterfly-shaped optical cable subunit (10), the first butterfly-shaped optical cable subunit (10) comprising: Sheath (4), which contains fiber optic unit (2) and reinforcing member (3); The docking structure (5) includes a male docking end (50) and a female docking end (51) disposed on the sheath (4), wherein the male docking end (50) is used to dock with the female docking end (51) of another first butterfly optical cable subunit (10); A peeling guide (6) is provided on the sheath (4) and is used to separate the male end (50) mated to the female end (51) from the female end (51).

2. The modular nested butterfly optical cable as described in claim 1, characterized in that: The butterfly-shaped optical cable further includes a second butterfly-shaped optical cable subunit (11), which includes: Sheath (4), which contains fiber optic unit (2) and reinforcing member (3); The male connector (50) is located on the sheath (4).

3. The modular nested butterfly optical cable as described in claim 1, characterized in that: The butterfly-shaped optical cable further includes a third butterfly-shaped optical cable subunit (12), which includes: Sheath (4), which contains fiber optic unit (2) and reinforcing member (3); The female connector (51) is located on the sheath (4); A peeling guide (6) is provided on the sheath (4) and is used to separate the male end (50) mated to the female end (51) from the female end (51).

4. A modular nested butterfly optical cable as described in claim 1, characterized in that: The male end (50) includes a guide protrusion, and the female end (51) includes a guide groove.

5. A modular nested butterfly optical cable as described in claim 4, characterized in that: The width of the guide groove is less than the maximum width of the guide protrusion.

6. A modular nested butterfly optical cable as described in claim 1, characterized in that: The bottom of the sheath (4) is provided with a guide groove extending along the length direction, and the bottom of the guide groove is formed with an angle. The peeling guide part (6) is formed at the angle at the bottom of the guide groove.

7. A modular nested butterfly optical cable as described in claim 1, characterized in that: The reinforcing member (3) includes steel wire and / or glass fiber reinforced plastic rod.

8. A modular nested butterfly optical cable as described in claim 7, characterized in that: The reinforcing member (3) also includes a power line, and in the plurality of the first butterfly optical cable sub-units (10), at least one of the reinforcing members (3) is configured as a power line.

9. A modular nested butterfly optical cable as described in claim 1, characterized in that: Among the multiple first butterfly optical cable sub-units (10), at least two of the first butterfly optical cable sub-units (10) have different sheath (4) materials.

10. A modular nested butterfly optical cable as described in claim 1, characterized in that: The surface of the sheath (4) is provided with a visual identification mark.

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