Branch connection structure applied to submarine optical cable

Abstract

A branch connection structure applied to a submarine optical cable comprises a fixed bottom plate (1) and a main optical cable (2), and is characterized in that a branch fiber coiling box body (4) is fixed on the fixed bottom plate (1), the main optical cable (2) is fixed on the fixed bottom plate (1), one or more branch optical cables (3) are branched after penetrating into the branch fiber coiling box body (4), and the branch optical cables (3) penetrate out of the branch fiber coiling box body (4). The branch optical cable (3) and the branch fiber coiling box body (4) are sealed and fixed through a watertight cable gland (18), an inner cavity of the branch fiber coiling box body (4) is encapsulated through a resin colloid (9), and the outer surfaces of sealing fixing parts of the fixing bottom plate (1), the branch fiber coiling box body (4) and the branch optical cable (3) are integrally vulcanized and sealed. And the optical cable has good waterproof performance, low cost and low loss, and can maintain the original performance of the main optical cable.

Description

Technical Field

[0001] This invention relates to an optical cable connection structure, and more particularly to a branch connection structure for use in submarine optical cables, belonging to the field of submarine optical cable technology. Background Technology

[0002] In fields such as marine communication, seabed environmental monitoring, and marine resource exploration, submarine optical cables serve as the core transmission carrier, and their application scenarios are constantly expanding. In particular, in distributed sensing applications, it is necessary to use optical cable branches to achieve multi-point signal acquisition and data transmission in order to meet the monitoring needs of large-scale and high-coverage applications.

[0003] Traditionally, the mainstream method for branching submarine optical cables requires disconnecting the main trunk cable and then splicing the branches using splice boxes. This approach is not only costly but also has numerous drawbacks and defects. The main shortcomings of this traditional method are: First, after the main trunk cable is disconnected, its original load-bearing structure is damaged. Even with reinforcement using splice boxes, it is difficult to restore the original tensile strength, making it unable to withstand the complex mechanical environment of the seabed. Second, the branching structure relies on the mechanical fixing and sealing design of the splice boxes, resulting in poor overall structural stability. Furthermore, it is susceptible to sealing failure due to the harsh environment of the ocean, such as high pressure and strong currents. Third, the increased number of fiber optic splice nodes not only reduces the reliability of optical cable transmission but also generates significant additional losses, severely impacting signal transmission quality and the accuracy of sensor data.

[0004] The aforementioned shortcomings prevent traditional submarine optical cable branching technologies from meeting the core requirements of distributed sensing applications for low loss, high reliability, low cost, and structural stability, thus hindering the large-scale deployment and application expansion of submarine distributed sensing systems. Therefore, developing a branching technology that can maintain the original performance of the trunk optical cable while achieving low cost and low loss has become a long-standing technical challenge in this field. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing submarine optical cable branching connections, which require disconnecting the main optical cable and then splicing the branches through a junction box. This process is not only costly but also suffers from numerous drawbacks, such as difficulty in waterproofing and sealing, and significant additional losses, which are detrimental to distributed sensing applications. The invention provides a branching connection structure for submarine optical cables that is structurally sound, does not require disconnecting the main optical cable, has high overall structural strength, good waterproof performance, low cost, low loss, and maintains the original performance of the main optical cable.

[0006] To achieve the above objectives, the technical solution of the present invention is: a branch connection structure for submarine optical cables, comprising a fixed base plate, a main optical cable, and branch optical cables. A branch fiber optic reel box is fixed on the fixed base plate. The main optical cable is fixed on the fixed base plate and, after passing through the branch fiber optic reel box, branches out one or more branch optical cables. The branch optical cables pass through the branch fiber optic reel box, and the branch optical cables and the branch fiber optic reel box are sealed and fixed together by a watertight gland. The inner cavity of the branch fiber optic reel box is filled with resin colloid. The outer surfaces of the sealing and fixing components of the fixed base plate, the branch fiber optic reel box, and the branch optical cables are vulcanized and sealed as a whole to form a vulcanized colloid.

[0007] Furthermore, the upper part of the branch fiber optic box body is provided with an opening, and a branch fiber optic box cover is installed at the upper opening of the branch fiber optic box body by fixing screws.

[0008] Furthermore, the branch optical cable is provided with connecting covers at the points where it enters and exits the branch fiber optic box. The connecting covers have insertion holes, through which the branch optical cable passes. One end of the connecting cover is fixed to the branch fiber optic box, and the other end of the connecting cover is fixed to the base plate.

[0009] Furthermore, one end of the connecting cover is fixed to the branch fiber optic box body by cover fixing screws, and the other end of the connecting cover is fixed to the base plate by cover fixing screws.

[0010] Furthermore, a miniature gland assembly is provided on the outer wall of the branch fiber optic box.

[0011] Furthermore, the trunk optical cable is fixedly connected to both ends of the fixed base plate by cable clamping blocks.

[0012] Furthermore, a branch fixing clamp is fixed on the main optical cable, the branch optical cable is fixed on the branch fixing clamp, and a lifting ring is connected to the branch fixing clamp.

[0013] Furthermore, a vulcanizing fastener is provided at the bottom of the fixed base plate, and the bottom of the vulcanizing fastener is secured to the fixed base plate by washers and connecting screws.

[0014] Furthermore, the watertight gland includes a clamping nut, a screw body, and a sealing plug. The screw body is sleeved on the branch optical cable located on one side of the branch fiber optic box. The threaded end of the screw body extends to the outside of the branch fiber optic box. A clamping nut is installed on the threaded end of the screw body. A sealing plug is provided between the screw body and the outer wall of the branch optical cable.

[0015] Furthermore, a pressure plug is provided between the clamping nut and the screw body, an O-ring is provided at the contact point between the screw body and the outer wall of the branch fiber optic cable, and a backstop ring is also provided between the screw body and the outer wall of the branch optical cable.

[0016] The beneficial effects of this invention are:

[0017] 1. This invention adopts a branch connection main structure consisting of a fixed base plate and a branch fiber optic cable box. It can achieve low-cost branching without disconnecting the main optical cable. The branch optical cable is well fixed and protected by the branch fiber optic cable box, connection cover, branch fixing clamp, etc., ensuring the reliability of the connection and fixation of vulnerable parts such as branch optical cable forks and connections.

[0018] 2. The present invention vulcanizes the entire periphery of the device, and the outer layer is completely covered by the external vulcanized colloid to achieve an outer layer seal. The inside of the branch fiber disc box cover is filled with resin to form an inner second seal, which can prevent water from entering the branch sealing box and also enhance the overall structural strength. The two seals achieve a very good waterproof sealing effect.

[0019] 3. The present invention has a reasonable structure, low cost, and high reliability of branch connection parts. Even if the branch optical cable is dragged by external force, it is not easy to be pulled off. It also ensures low loss and can maintain the original performance of the trunk optical cable, which is conducive to the large-scale deployment and application expansion of submarine distributed sensing systems. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0021] Figure 2 This is a side view of the present invention.

[0022] Figure 3 This is a top view of the present invention.

[0023] Figure 4 This is a schematic diagram of the internal structure after the present invention has been potted.

[0024] Figure 5 This is a schematic diagram of the internal structure of the present invention.

[0025] Figure 6 This is a schematic diagram of the structure of the branching disc fiber box of the present invention.

[0026] Figure 7 yes Figure 6 Cross-sectional view.

[0027] Figure 8 This is a schematic diagram of the branch fixing clamp of the present invention.

[0028] Figure 9 This is a schematic diagram of the structure of the watertight gland of the present invention.

[0029] Figure 10 yes Figure 9 Cross-sectional view.

[0030] In the diagram: 1. Fixed base plate; 2. Main optical cable; 3. Branch optical cable; 4. Branch fiber optic cable housing; 5. Branch fiber optic cable housing cover; 6. Countersunk screw; 7. Connecting cover; 8. Fixing screw; 9. Resin colloid; 10. Vulcanized colloid; 11. Branch fixing clamp; 12. Cable clamp; 13. Vulcanized fixing component; 14. Washer; 15. Connecting screw; 16. Lifting eye; 17. Miniature gland assembly; 18. Watertight gland; 19. Compression nut; 20. Screw body; 21. Compression plug; 22. Sealing plug; 23. Anti-reverse ring; 24. O-ring seal. Detailed Implementation

[0031] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] See Figures 1 to 10 The present invention discloses a branch connection structure for submarine optical cables, comprising a fixed base plate 1, a main optical cable 2, and branch optical cables 3. The structure is characterized in that: a branch fiber optic reel 4 is fixed on the fixed base plate 1; the main optical cable 2 is fixed on the fixed base plate 1 and, after passing through the branch fiber optic reel 4, branches out as one or more branch optical cables 3; the branch optical cables 3 pass through the branch fiber optic reel 4; the branch optical cables 3 and the branch fiber optic reel 4 are sealed and fixed together by a watertight gland 18; the inner cavity of the branch fiber optic reel 4 is filled with resin 9; and the outer surfaces of the sealing and fixing components of the fixed base plate 1, the branch fiber optic reel 4, and the branch optical cables 3 are integrally vulcanized and sealed to form a vulcanized colloid 10.

[0033] The upper part of the branch fiber optic box 4 is provided with an opening, and the branch fiber optic box cover 5 is installed at the upper opening of the branch fiber optic box 4 by fixing screws 6.

[0034] The branch optical cable 3 is provided with a connecting cover 7 at the part where it enters and exits the branch fiber optic box 4. The connecting cover 7 has an insertion hole. The branch optical cable 3 passes through the insertion hole on the connecting cover 7. One end of the connecting cover 7 is fixed to the branch fiber optic box 4, and the other end of the connecting cover 7 is fixed to the fixed base plate 1.

[0035] One end of the connecting cover 7 is fixed to the branch fiber optic box 4 by the cover fixing screw 8, and the other end of the connecting cover 7 is fixed to the fixed base plate 1 by the cover fixing screw 8.

[0036] A miniature gland assembly 17 is provided on the outer wall of the branch fiber optic box 4.

[0037] The trunk optical cable 2 is fixedly connected to both ends of the fixed base plate 1 by cable clamping blocks 12.

[0038] The main optical cable 2 is fixed with a branch fixing clamp 11, the branch optical cable 3 is fixed on the branch fixing clamp 11, and a lifting ring 16 is connected to the branch fixing clamp 11.

[0039] The bottom of the fixed base plate 1 is provided with a vulcanizing fastener 13, and the bottom of the vulcanizing fastener 13 is fixed to the fixed base plate 1 by a washer 14 and a connecting screw 15.

[0040] The watertight gland 18 includes a clamping nut 19, a screw body 20, and a sealing plug 22. The screw body 20 is sleeved on the branch optical cable 3 located inside the branch fiber optic box 4. The threaded end of the screw body 20 extends to the outside of the branch fiber optic box 4. The clamping nut 19 is installed on the threaded end of the screw body 20. A sealing plug 22 is provided between the screw body 20 and the outer wall of the branch optical cable 3.

[0041] A pressure plug 21 is provided between the clamping nut 19 and the screw body 20. An O-ring 24 is provided at the contact part between the screw body 20 and the outer wall of the branch fiber optic box 4. A backstop ring 23 is also provided between the screw body 20 and the outer wall of the branch optical cable 3.

[0042] See Figures 1 to 10 This invention addresses the technical challenges of existing submarine optical cable branching methods, which require disconnecting the main optical cable before splicing via junction boxes. This process is costly, difficult to waterproof and seal, and results in significant additional losses. This invention effectively solves these problems through ingenious structural design and waterproofing technology, achieving unexpected technical results. The specific structure is as follows:

[0043] The branch sections of the main optical cable 2 are positioned on the fixed base plate 1. A branch fiber optic reel 4 is fixed to the fixed base plate 1. The branching points of the main optical cable 2 into the branch optical cable 3 are located inside the branch fiber optic reel 4. The branch fiber optic reel 4 not only provides fixation and protection but also creates favorable conditions for the potting resin. The branch fiber optic reel 4 has an open-top structure, and a branch fiber optic reel cover 5 is provided at the upper opening of the branch fiber optic reel 4. The branch fiber optic reel cover 5 is fixed to the branch fiber optic reel 4 by fixing screws 6.

[0044] After the main optical cable 2 passes through the branch fiber optic reel box 4, one or more branch optical cables 3 are branched out. The branch optical cables 3 and the branch fiber optic reel box 4 are sealed and fixed by a watertight gland 18, which serves both fixing and sealing functions. The watertight gland 18 includes a clamping nut 19, a screw body 20, and a sealing plug 22. The screw body 20 is fitted onto the branch optical cable 3 located inside the branch fiber optic reel box 4, with the threaded end of the screw body 20 extending to the outside of the branch fiber optic reel box 4. The clamping nut 19 is installed on the threaded end of the screw body 20. A sealing plug 22 is provided between the screw body 20 and the outer wall of the branch optical cable 3. A backlash ring 23 is also provided between the screw body 20 and the outer wall of the branch optical cable 3. In addition, a pressure plug 21 is provided between the clamping nut 19 and the screw body 20. After the clamping nut 19 is installed on the screw body 20, it can press the pressure plug 21 and the sealing plug 22 together, achieving a good waterproof seal. An O-ring 24 is provided at the contact point between the screw body 20 and the outer wall of the branch fiber optic box 4, and the O-ring 24 is used to seal the screw body 20 and the outer wall of the branch fiber optic box 4.

[0045] To effectively protect the portions of the branch optical cable 3 that enter and exit the branch fiber optic coil cassette 4, this application provides connecting covers 7 at both entry and exit points. The connecting covers 7 are metal plate or metal frame structures with entry holes. One end of the connecting cover 7 is fixed to the branch fiber optic coil cassette 4 using cover fixing screws 8, and the other end is fixed to the base plate 1 using cover fixing screws 8. The branch optical cable 3 passes through the entry holes in the connecting covers 7, with one end fixed to the branch fiber optic coil cassette 4 and the other end fixed to the base plate 1. This ensures that the portions of the branch optical cable 3 entering and exiting the branch fiber optic coil cassette 4 are located inside the connecting covers 7, providing excellent protection and effectively preventing impact or compression.

[0046] During installation, the outer sheath of the main optical cable 2 is first stripped down to the steel pipe layer. The optical unit steel pipe is then disconnected, leaving a sufficient length for fiber optic splicing. The disconnected optical unit fiber is then spliced ​​to the branch optical cable 3. Water-sealed glands 18 are used to seal the branch optical cable 3 and the branch fiber optic coil housing 4 internally, and the optical unit is sealed to the branch sealing housing 4. After assembly, the inside of the branch fiber optic coil housing cover 5 is filled with resin to form an inner seal, preventing water from entering the branch sealing housing 4 and enhancing the overall structural strength. Even when subjected to external force, the branch optical cable 3 is not easily pulled off. The entire encapsulated device is then placed back into the mold for overall outer vulcanization. The outer vulcanized adhesive 10 completely covers the device, forming an outer seal. Even if the outer vulcanized adhesive 10 is damaged by external force, the inner layer still provides a second layer of protection to prevent water from entering the branch sealing housing 4, achieving excellent waterproof sealing.

[0047] In addition, the trunk optical cable 2 is fixedly connected to the two ends of the fixed base plate 1 by cable clamps 12, which ensures a reliable connection and fixation between the trunk optical cable 2 and the fixed base plate 1. At the same time, it can also prevent stress concentration and damage caused by radial force on the ends of the trunk optical cable 2 and the fixed base plate 1. A branch fixing clamp 11 is fixed on the trunk optical cable 2, and the branch optical cable 3 is fixed on the branch fixing clamp 11, so that the branch optical cable 3 can only be subjected to axial force, preventing the branch optical cable 3 from tearing the vulcanized body after being subjected to force.

[0048] The above description is a further detailed explanation of the present invention in conjunction with specific embodiments. It should not be considered that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, any simple modifications and substitutions made without departing from the concept of the present invention should be considered to fall within the protection scope of the present invention.

Claims

1. A branch connection structure for submarine optical cables, comprising a fixed base plate (1), a main optical cable (2), and branch optical cables (3), characterized in that: A branch fiber optic cable box (4) is fixed on the fixed base plate (1). The main optical cable (2) is fixed on the fixed base plate (1) and after passing through the branch fiber optic cable box (4), one or more branch optical cables (3) are branched out. The branch optical cables (3) pass through the branch fiber optic cable box (4). The branch optical cables (3) and the branch fiber optic cable box (4) are sealed and fixed by a watertight gland (18). The inner cavity of the branch fiber optic cable box (4) is filled with resin colloid (9). The outer surfaces of the sealing and fixing parts of the fixed base plate (1), the branch fiber optic cable box (4) and the branch optical cables (3) are vulcanized and sealed to form a vulcanized colloid (10).

2. The branch connection structure for submarine optical cables according to claim 1, characterized in that: The upper part of the branch fiber optic box body (4) is provided with an opening, and the branch fiber optic box cover (5) is installed at the upper opening of the branch fiber optic box body (4) by fixing screws (6).

3. The branch connection structure for submarine optical cables according to claim 1, characterized in that: The branch optical cable (3) is provided with a connecting cover (7) at the part where it enters and exits the branch fiber optic box (4). The connecting cover (7) has an insertion hole. The branch optical cable (3) passes through the insertion hole on the connecting cover (7). One end of the connecting cover (7) is fixed on the branch fiber optic box (4), and the other end of the connecting cover (7) is fixed on the fixed base plate (1).

4. The branch connection structure for submarine optical cables according to claim 1, characterized in that: One end of the connecting cover (7) is fixed to the branch fiber optic box (4) by the cover fixing screw (8), and the other end of the connecting cover (7) is fixed to the fixed base plate (1) by the cover fixing screw (8).

5. A branch connection structure for submarine optical cables according to claim 1 or 2, characterized in that: A miniature gland assembly (17) is provided on the outer wall of the branch disc fiber box body (4).

6. The branch connection structure for submarine optical cables according to claim 1, characterized in that: The trunk optical cable (2) is fixedly connected to both ends of the fixed base plate (1) by cable clamps (12).

7. The branch connection structure for submarine optical cables according to claim 1, characterized in that: The main optical cable (2) is fixed with a branch fixing clamp (11), the branch optical cable (3) is fixed on the branch fixing clamp (11), and a lifting ring (16) is connected to the branch fixing clamp (11).

8. The branch connection structure for submarine optical cables according to claim 1, characterized in that: The bottom of the fixed base plate (1) is provided with a vulcanizing fastener (13), and the bottom of the vulcanizing fastener (13) is attached to the fixed base plate (1) by a washer (14) and a connecting screw (15).

9. A branch connection structure for submarine optical cables according to claim 1, characterized in that: The watertight gland (18) includes a clamping nut (19), a screw body (20), and a sealing plug (22). The screw body (20) is fitted onto the branch optical cable (3) located inside the branch fiber optic box (4). The threaded end of the screw body (20) extends to the outside of the branch fiber optic box (4). The clamping nut (19) is installed on the threaded end of the screw body (20). A sealing plug (22) is provided between the screw body (20) and the outer wall of the branch optical cable (3).

10. A branch connection structure for submarine optical cables according to claim 9, characterized in that: A pressure plug (21) is provided between the clamping nut (19) and the screw body (20), an O-ring (24) is provided at the contact part between the screw body (20) and the outer wall of the branch fiber optic box (4), and a backstop ring (23) is also provided between the screw body (20) and the outer wall of the branch optical cable (3).

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