Indoor distribution optical cable easy to be laterally accessed and connected
By using GFRP strips and straight loose sleeves in indoor distribution optical cables, the problem of fiber damage during lateral splicing construction was solved, achieving efficient construction and mechanical protection.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- YANGTZE OPTICAL FIBRE & CABLE CO LTD
- Filing Date
- 2023-06-27
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies struggle to efficiently install indoor optical cables, necessitating a solution for lateral splicing without damaging the optical fiber.
Two GFRP strips are embedded in the outer sheath, and the loose tube units are arranged in a straight position. By limiting the distribution area of the loose tubes, the GFRP strips block the cutting tool when opening the window, thus avoiding damage to the optical fiber.
This method enables optical fibers to be protected from damage during lateral splicing, improving construction efficiency, reducing the number of fusion splices, and enhancing the mechanical protection and water-blocking properties of the optical cable.
Smart Images
Figure CN116736458B_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of optical cables, and more specifically, relates to an indoor distribution optical cable that is easy to install by lateral splicing. Background Technology
[0002] Multi-core optical cables are widely used in high-density indoor and outdoor applications, with branch cables and distribution cables being common types. Distribution cables are suitable for indoor and indoor / outdoor applications, trunk lines within and between buildings, patch panels, cabling between telecommunications equipment rooms, and connection cables in riser and pressurized environments, horizontal cabling for FTTD, data center EDA areas, and factory automation.
[0003] Currently, a method for installing indoor optical cables with side-opening windows has been developed. The principle is to create an opening on the side of the cable body, remove the optical unit for splicing, and then perform the splicing without stripping the cable core from the end face. Examples include Chinese patent documents CN219046149U and CN115657232A.
[0004] The first step in the splicing process, when opening the side of the cable (i.e., the "windowing" operation), requires using a cutting edge to cut open the outer sheath, which has high mechanical strength, and necessitates manually applying significant lateral pressure. Because of the sheath's high strength, the lateral pressure is difficult to control. Furthermore, the internal cable core structure is compact, requiring the use of a cutting tool to create the opening. During this opening process, damage to the optical fibers inside the loose tube is inevitable, leading to losses and potential hazards. Summary of the Invention
[0005] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides an indoor distribution optical cable that is easy to install by side-cutting. It is mainly used for the rapid installation of optical cables between ADP and AP, which can improve the efficiency of cable cutting construction.
[0006] To achieve the above objectives, according to the present invention, an indoor distribution optical cable that is easy to install by lateral tapping is provided, comprising an outer sheath, two GFRP strips, and multiple loose tube units, characterized in that:
[0007] Each of the GFRP strips is respectively embedded on the outer sheath, and there is a gap between the two GFRP strips;
[0008] Each of the loose tube units is disposed in the inner cavity of the outer sheath in a straight manner, and each of the loose tube units includes a loose tube and one or more optical fibers disposed inside the loose tube.
[0009] In the cross-section of the indoor optical fiber cable, each GFRP strip is circular. Two circular GFRP strips have an outer common tangent l1 and an outer common tangent l2. The outer common tangent l1 divides the inner edge of the outer sheath's cross-section into a region of area A1 and a region of area A2, where A1 ≤ A2. The outer common tangent l2 divides the inner edge of the outer sheath's cross-section into a region of area A3 and a region of area A4, where A3 ≤ A4. Furthermore:
[0010] When the outer edges of all loose tubes are within the area of A2, the outer edge of any one of the loose tubes does not exceed the common tangent l1.
[0011] And / or,
[0012] When the outer edges of all loose tubes are within the area of A4, the outer edge of any one of the loose tubes does not exceed the common tangent l2.
[0013] Preferably, when A1 < A2 and the outer edges of the circles of all loose tubes enter the area of area A1, the outer edge of any one of the loose tubes does not exceed the common tangent l1.
[0014] And / or,
[0015] When A3 < A4 and the outer edges of all loose tubes' circles enter the region with area A3, the outer edge of any one of the loose tubes does not exceed the common tangent l2.
[0016] Preferably, the sum of the areas of the outer edges of all loose sleeves, A s The ratio A to the area A of the inner edge of the outer sheath s / A = 0.4 to 0.8.
[0017] Preferably, it also includes a peeling marking rib, which is disposed on the outer wall of the outer sheath and is distributed in a triangle with the two GFRP strips.
[0018] Preferably, the outer edge of the cross-section of the outer sheath is circular and the inner edge is elliptical, and the straight line containing the minor axis of the inner edge of the outer sheath passes through each of the GFRP strips.
[0019] Preferably, the diameter of the outer edge of the cross-section of the outer sheath is 8mm to 13.5mm, the length of the major axis of the inner edge of the cross-section of the outer sheath is 5.2mm to 10.7mm, and the length of the minor axis is 3.8mm to 9.3mm.
[0020] Preferably, the outer diameter of the loose sleeve is 0.9mm to 1.3mm and the inner diameter is 0.6mm to 1.04mm.
[0021] Preferably, the inner cavity of the outer sheath is provided with only a plurality of loose tube units, and the indoor distribution optical cable is a non-metallic optical cable.
[0022] Preferably, the tensile strength of the outer sheath is 12MPa to 14MPa.
[0023] Preferably, the loose tube has a breaking strength of 10MPa to 11.5MPa, and each optical fiber is a bend-insensitive optical fiber.
[0024] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:
[0025] 1) This invention arranges two circular GFRP (glass fiber reinforced plastic) strips. When cutting the outer sheath to create a skylight using a cutting tool, the cutting edge of the cutting tool will push all the loose tube units to one end of the outer sheath cavity. However, after the cutting edge contacts both the GFRP strips, the cutting edge can be regarded as the common tangent of the two circular GFRP strips. Because this invention sets the distribution of the loose tube units, the cutting tool can be blocked by the two GFRP strips when cutting the outer sheath, and will not cut below the common tangent of the GFRP strips. During the skylight construction process, the optical fiber inside the loose tube will not be damaged.
[0026] 2) This invention is designed for indoor optical cable applications. Since the cable is protected by buildings and installation pipes, it is rarely damaged by rainwater erosion or lateral pressure impact. Therefore, the armor, water-blocking, tensile, and compressive structures between the loose tube and the outer sheath are eliminated. Furthermore, multiple loose tubes are loosely placed directly in the outer sheath, allowing the optical unit to be easily removed after opening the side window, thus enabling lateral splicing installation.
[0027] In a preferred embodiment, to improve the lateral pressure resistance, tensile strength, and water-blocking performance of the indoor distribution optical cable, its sheath tensile strength is 12MPa to 14MPa, ensuring easy implementation of lateral window opening operations while providing good mechanical protection. FRP reinforcement is embedded in the sheath to improve lateral pressure and tensile strength; and water-blocking elements are installed in the loose tube to improve the overall water-blocking performance of the optical cable. Alternatively, if these elements are not placed between the sheath and the loose tube, the characteristic of the loose tube optical unit being easily extracted laterally is maintained.
[0028] This invention adopts a minimalist structure, so indoor optical cables do not need to worry about rainwater erosion. Several loose tube units are placed in the outer sheath, and the outer sheath has two non-metallic reinforcing cores such as GFRP strips embedded in it as tensile elements. It has the characteristics of small size, light weight and simple manufacturing process.
[0029] 3) The inner design of the outer sheath is an elliptical structure, which allows the GFRP strips to be arranged in the short axis direction of the inner wall of the outer sheath. This makes the GFRP strips thicker, protecting the strength of the outer sheath. At the same time, the thickness of the part that can be used for opening the window is thinner, making it easier to open the window. With the same fiber core, the cable diameter is easier to make smaller.
[0030] 4) When the inner cavity of the outer sheath is elliptical, the loose tube units inside are arranged at the bottom of the ellipse when a window is opened on the outer sheath, not exceeding the height of the GFRP at both ends, thus avoiding damage to the optical fiber. At the same time, when the loose tube units are vertically aligned, the loose tube units can ensure a relatively long tube length, allowing longer loose tube units to be tubed out.
[0031] 5) Combined with bend-insensitive optical fiber and ultra-flexible loose tube with a breaking strength of 10MPa to 11.5MPa, the loose tube unit has good bending performance and can be bent and coiled in small-sized optical junction boxes, avoiding the conventional method of breaking optical cables and reducing the number of splice points.
[0032] 6) When the indoor wiring optical cable of the present invention is laid vertically in one go, it can be stored in the weak current well. Because it is a non-metallic optical cable, it does not need to be grounded and can be protected against lightning and electricity. Attached Figure Description
[0033] Figure 1 This is a schematic diagram of the present invention in its conventional, unpeeled state;
[0034] Figure 2 This is a schematic diagram of how multiple loose sleeve units are pushed together when the skylight is opened according to the present invention. Detailed Implementation
[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.
[0036] Reference Figure 1 An indoor distribution optical cable that is easy to install by lateral tapping includes an outer sheath 5, two GFRP strips 4 and multiple loose tube units.
[0037] The outer sheath 5 is made of low-smoke halogen-free flame-retardant polyolefin material, which gives the optical cable flame-retardant properties. The tensile strength of the outer sheath 5 is 12MPa to 14MPa. This tensile strength allows the outer sheath 5 and the optical cable as a whole to cope well with external stress and resist deformation.
[0038] Each GFRP strip 4 is embedded in the outer sheath 5, and each GFRP strip 4 does not extend beyond the inner wall or the outer wall of the outer sheath 5. There is a gap between two GFRP strips 4. The GFRP strips 4 act as reinforcements, improving the overall strength of the outer sheath 5 and allowing it to maintain its basic shape.
[0039] The inner cavity of the outer sheath 5 only houses multiple loose tube units, without any other fillers such as grease. Therefore, no foreign objects will affect the removal of the loose tube units. Furthermore, each loose tube unit is placed vertically within the inner cavity of the outer sheath 5. This vertical placement contrasts with a twisted arrangement. Conventional structures typically involve multiple loose tube units arranged in a twisted manner within the outer sheath 5, resulting in a larger excess length for the loose tube units. In contrast, the loose tube 2 of this invention is placed vertically, not twisted, making it easier to remove and branch.
[0040] Each of the loose tube units includes a loose tube 2 and one or more optical fibers 3 disposed within the loose tube 2. The loose tube contains a water-blocking element, which is water-blocking yarn, water-blocking powder, or grease.
[0041] In the cross-section of the indoor optical fiber cable, each of the GFRP strips 4 is circular. The two circular GFRP strips have an outer common tangent l1 and an outer common tangent l2. The outer common tangent l1 divides the inner edge of the cross-section of the outer sheath 5 into a region of area A1 and a region of area A2, where A1 ≤ A2. The outer common tangent l2 divides the inner edge of the cross-section of the outer sheath 5 into a region of area A3 and a region of area A4, where A3 ≤ A4. If the area of the inner edge of the cross-section of the outer sheath 5 is A, then A1 + A2 = A3 + A4 = A. Furthermore:
[0042] When the outer edges of all loose tubes 2 are within the area of A2, the outer edge of any one of the loose tubes 2 does not exceed the common tangent l1. That is, at this time, it is ensured that the outer edges of all loose tubes 2 are on the same side of the common tangent l1. The area of A2 can accommodate the outer edges of all loose tubes 2. The area of A2 is large enough to ensure that the outer edges of all loose tubes 2 do not exceed the area of A2. Preferably, it is ensured that there is a gap between the outer edge of any loose tube 2 and the common tangent l1, so that the area of A2 has enough space to accommodate all loose tubes 2.
[0043] And / or,
[0044] When the outer edges of all loose tubes 2 are within the area of A4, the outer edge of any one of the loose tubes 2 does not exceed the external common tangent l2. That is, at this time, it is ensured that the outer edges of all loose tubes 2 are on the same side of the external common tangent l2. The area of A4 can accommodate the outer edges of all loose tubes 2, and the outer edges of all loose tubes 2 do not exceed the area of A4. Preferably, it is ensured that there is a gap between the outer edge of any loose tube 2 and the external common tangent l2, so that the area of A4 has enough space to accommodate all loose tubes 2.
[0045] This invention limits the total distribution area of the loose tubes 2 because when cutting the opening in the outer sheath 5 with a cutting tool, the straight cutting edge of the cutting tool will push all the loose tube units to one end of the inner cavity of the outer sheath 5, as shown in the reference. Figure 2 At this point, all loose tube units are located on the same side of the blade. However, after the blade contacts both GFRP strips 4, the straight blade can be considered as the common tangent of the two circular GFRP strips 4. At this time, on the cross-section of the indoor distribution optical cable passing through the blade, the outer edges of all loose tubes 2 are pushed into a region by the blade. Because this invention limits the distribution of the region after all loose tube units are pushed to one end, the cutting tool can be blocked by the two GFRP strips 4 when cutting the outer sheath 5, and will not cut below the common tangent of the two GFRP strips 4. During the process of opening the skylight, the optical fiber 3 inside the loose tube 2 will not be damaged. In the "and / or" relationship above, if it is an "or" relationship, the cutting tool can cut from one side of the outer sheath 5 to open the skylight; if it is an "and" relationship, it can cut from either side of the opposite sides of the outer sheath 5 to open the skylight.
[0046] Furthermore, when A1 < A2 and the outer edges of all loose tubes 2 are within the area of A1, the outer edge of any one of the loose tubes 2 will not exceed the common tangent line l1, and thus will not exceed l2. Preferably, there is a gap between the outer edge of any one of the loose tubes 2 and the common tangent line l1. Similarly, when A3 < A4 and the outer edges of all loose tubes 2 are within the area of A3, the outer edge of any one of the loose tubes 2 will not exceed the common tangent line l2, and thus will not exceed l1. Preferably, there is a gap between the outer edge of any one of the loose tubes 2 and the common tangent line l2. This results in a smaller total distribution area of all loose tubes 2, making it easier to cut the outer sheath 5 from either side of the outer sheath 5 to create an opening and remove the loose tube unit.
[0047] Furthermore, the sum of the areas of the outer edges of all loose sleeves 2, A s The ratio A of the area A of the inner edge of the outer sheath 5 to the area A of the inner edge of the outer sheath 5 s / A = 0.4 to 0.8. If the ratio is small, the total distribution area of the loose tube 2 is also small, making it less likely to damage the loose tube unit during cutting. If the ratio is large, a higher core density can be obtained.
[0048] Furthermore, the present invention also includes a peeling marking ridge 1, which is disposed on the outer wall of the outer sheath 5, and the peeling marking ridge 1 and the two GFRP strips 4 are triangularly distributed. The peeling marking ridge 1 serves as a positioning point for peeling, and there are no GFRP strips 4 in this part, making it convenient to peel the outer sheath 5 from this point. If a window can be opened from either side of the opposite sides of the outer sheath 5, two peeling marking ridges 1 can be provided, with the two peeling marking ridges 1 respectively on both sides of the line connecting the two GFRP strips 4.
[0049] Furthermore, the outer edge of the cross-section of the outer sheath 5 is circular, while the inner edge is preferably elliptical. The short axis of the inner edge of the outer sheath 5 passes through each of the GFRP strips 4. The GFRP strips 4 can be arranged along the short axis of the inner wall of the outer sheath 5, allowing the GFRP strips 4 to be made relatively thick, ensuring the strength of the outer sheath 5, while allowing for a thinner thickness for the skylight opening, making it easier to open the skylight. Preferably, the two GFRP strips 4 have the same diameter, and the short axis of the inner edge of the outer sheath 5 passes through the center of each GFRP strip 4, while the long axis of the inner edge of the outer sheath 5 passes through the two peeling marking ribs 1. This makes it easier to cut the outer sheath 5 from any location of the peeling marking rib 1.
[0050] Furthermore, the indoor optical cable is a non-metallic optical cable that can be stored in a low-voltage well. Because it is a non-metallic optical cable, it does not require grounding and can be protected against lightning and electricity.
[0051] Furthermore, the diameter of the outer edge of the cross-section of the outer sheath 5 is 8mm to 13.5mm, the length of the major axis of the inner edge of the cross-section of the outer sheath 5 is 5.2mm to 10.7mm, and the length of the minor axis is 3.8mm to 9.3mm. The advantage of using such dimensions is that the inner cross-section is elliptical, which can effectively reduce the size and weight of the optical cable without affecting its construction and use.
[0052] Furthermore, the outer diameter of the loose tube 2 is 0.9mm to 1.3mm, and the inner diameter is 0.6mm to 1.04mm. The advantage of using such dimensions is that the fiber optic capacity ratio is high and the size is small.
[0053] Furthermore, the loose tube 2 has a breaking strength of 10MPa to 11.5MPa, and each optical fiber 3 is a bend-insensitive optical fiber 3. The bend-insensitive optical fiber 3, combined with the ultra-flexible loose tube 2 with a breaking strength of 10MPa to 11.5MPa, gives the loose tube unit good bending performance. The loose tube unit can be bent and coiled in a small-sized optical junction box, avoiding breakage of the optical cable and reducing the number of fusion splice points.
[0054] Reference Figure 2 When the opening is horizontal, the cutting tool can also push the internal loose tube units to one end. The internal loose tube units are arranged at the bottom of the ellipse, and no single loose tube unit exceeds the outer common tangent of two GFRP strips 4, thus preventing damage to the optical fiber 3. At the same time, when the loose tube units are vertical, the cutting tool can also push the loose tube units inside the outer sheath 5 to one end. The two GFRP strips 4 can block the cutting tool, effectively preventing the cutting tool from cutting the optical fiber 3. Moreover, the loose tube units occupy little space inside the outer sheath 5, allowing multiple loose tube units to remain in a relatively loose state. The loose tube units can be removed after the opening is made, thus ensuring a longer removal length.
[0055] Those skilled in the art will readily understand that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. An indoor optical distribution cable that is easy to install by lateral splicing, comprising an outer sheath, two GFRP strips, and multiple loose tube units, characterized in that: Each of the GFRP strips is respectively embedded on the outer sheath, and there is a gap between the two GFRP strips; Each of the loose tube units is disposed in the inner cavity of the outer sheath in a straight manner, and each of the loose tube units includes a loose tube and one or more optical fibers disposed inside the loose tube. On the cross-section of the indoor distribution optical cable, the two GFRF strips have an external common tangent. l 1 and the outer male tangent l 2. Grandfather's tangent l 1. Divide the inner edge of the cross-section of the outer sheath into regions of area A1 and area A2, where A1 ≤ A2, and the outer common tangent is... l 2. Divide the inner edge of the cross-section of the outer sheath into regions with area A3 and area A4, where A3 ≤ A4. Furthermore: When the outer edges of all loose sleeves enter the region of area A2, the outer edge of any one of the loose sleeves does not exceed the common tangent. l 1; And / or, When the outer edges of all loose sleeves enter the region of area A4, the outer edge of any one of the loose sleeves does not exceed the common tangent. l 2.
2. The indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, When A1 < A2 and the outer edges of all loose sleeves' circles enter the region with area A1, the outer edge of any one of the loose sleeves does not exceed the common tangent. l 1; And / or, When A3 < A4 and the outer edges of all loose sleeves' circles enter the region with area A3, the outer edge of any one of the loose sleeves does not exceed the common tangent. l 2.
3. The indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, The sum of the areas of the outer edges of all loose tubes, A s The ratio A to the area A of the inner edge of the outer sheath s / A=0.4~0.
8.
4. The indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, It also includes a peeling marking rib, which is disposed on the outer wall of the outer sheath and is distributed in a triangle with the two GFRP strips.
5. The indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, The outer edge of the cross-section of the outer sheath is circular and the inner edge is elliptical. The straight line containing the minor axis of the inner edge of the outer sheath passes through each of the GFRP strips.
6. An indoor optical distribution cable for easy lateral splicing construction according to claim 5, characterized in that, The diameter of the outer edge of the cross-section of the outer sheath is 8mm to 13.5mm, the length of the major axis of the inner edge of the cross-section of the outer sheath is 5.2mm to 10.7mm, and the length of the minor axis is 3.8mm to 9.3mm.
7. The indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, The outer diameter of the loose sleeve is 0.9mm to 1.3mm, and the inner diameter is 0.6mm to 1.04mm.
8. The indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, The inner cavity of the outer sheath is only provided with multiple loose tube units.
9. An indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, The tensile strength of the outer sheath is 12MPa ~ 14MPa.
10. An indoor optical distribution cable for easy lateral splicing construction according to claim 1, characterized in that, The loose tube has a breaking strength of 10MPa to 11.5MPa, and each optical fiber is a bend-insensitive fiber.