Gravity anchor capable of automatically and greatly adjusting length of mooring rope

Abstract

The invention discloses a gravity anchor capable of automatically and greatly adjusting the length of a mooring rope, and relates to the technical field of offshore mooring equipment, the gravity anchor comprises a gravity anchor body, the mooring rope, a sealing cover, a scaling box and a safety cable, the sealing cover comprises a flexible sealing sleeve and a cylindrical shell, the cylindrical shell is fixed to the gravity anchor body through bolts, and an overflowing hole is formed in the side wall of the cylindrical shell; a filter screen is mounted in the overflowing hole; the lower end of the flexible sealing sleeve is hermetically sleeved on the upper part of the cylindrical shell; the scaling box is located in the cylindrical shell and comprises an outer shell, a fixing shaft and a coil spring. The shell is fixed in the cylindrical shell, the fixed shaft is fixed in the shell, the coil spring is wound on the fixed shaft, one end of the coil spring is fixed on the fixed shaft, and the other end of the coil spring is connected with the cable; the cable penetrates out of the top of the flexible sealing sleeve and is fixedly connected with the flexible sealing sleeve in a sealed mode. One end of the safety cable is fixedly connected with the gravity anchor, and the other end is fixedly connected with the cable on the upper side of the flexible sealing sleeve; the device can realize automatic adjustment of the length of the cable through a pure mechanical structure according to the change of the water level without power supply.

Description

Technical Field

[0001] This invention relates to the field of marine mooring equipment technology, specifically to a gravity anchor that automatically and significantly adjusts the length of the mooring cable. Background Technology

[0002] Floating structures and facilities at sea are widely used in aquaculture facilities, observation and communication equipment, floating structures for wind, solar, and wave power generation, offshore resource exploration and exploitation platforms, and floating breakwaters, playing a vital role in my country's development of its deep-sea economy. Mooring systems are a key component of floating structures at sea, used for positioning.

[0003] Mooring systems generally consist of cables and anchors. Based on the type of cable, mooring systems are broadly classified into two types: catenary mooring and tension mooring. Catenary mooring relies primarily on the high strength and stiffness of the anchor chain to provide a stable mooring environment, with the anchor chain's own weight providing the restoring force. However, because catenary anchor chains occupy a large area on the seabed, impacting the environment and navigation safety, tension mooring is often used in such cases. Tension mooring typically uses lighter, newer materials as mooring cables, and its restoring force is mainly provided by the elasticity of the cable. Tensioning devices, such as winches fixed to the ship or offshore platform, are generally used to ensure the cable remains taut, effectively reducing ship drift and rolling, and providing a more stable mooring effect. Furthermore, tension mooring can withstand external forces such as strong winds, large waves, and tidal changes, providing greater stability and safety. However, when the water level drops, redundant mooring cable lengths in tensioned mooring systems can lead to large displacements and drifts of the floating structure; conversely, when the water level rises, insufficient mooring cable length can cause the floating structure to be submerged, endangering the safety of the floating structure and surrounding structures. Therefore, it is essential to adjust the cable length in a timely manner to ensure environmental and structural safety. Existing automatic winches for ship mooring are all electrically driven, which presents installation difficulties and resource waste when used for wave-damping facilities of floating bodies requiring long-term mooring without a power supply. Manually adjusting the cable length according to water level changes is time-consuming and labor-intensive. Especially with daily tides that can cause water level changes of several meters, there is an urgent need for a tensioned mooring system that can automatically adjust the length significantly.

[0004] Chinese patent CN106253814A discloses a floating photovoltaic anchoring device suitable for high water level differences, including a foundation with a semi-circular hole pre-drilled at the bottom; a fixed pulley installed on the upper part of the foundation; a slide track laid under the foundation, with a rotating iron ball on the slide track, the rotating iron ball having a pre-drilled cylindrical hole; a tripod mounted on the rotating iron ball, the bottom edge of the tripod passing through the cylindrical hole, the top of the tripod connected to a cable; the cable crossing the fixed pulley and connecting to the photovoltaic array, with an anti-collision device at the end of the photovoltaic array; a braking iron ball installed on the upper part of the tripod, the braking iron ball cooperating with the semi-circular hole; this device needs to be used near the shore and is not suitable for mooring floating facilities at sea. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a gravity anchor that automatically and significantly adjusts the length of the cable.

[0006] The technical solution of the present invention is: a gravity anchor that automatically adjusts the length of the cable by a large margin, comprising a gravity anchor, a cable, a sealing cover, a scaling box and a safety cable, wherein the sealing cover comprises a flexible sealing sleeve and a cylindrical shell, the cylindrical shell is installed on the gravity anchor and has a flow hole on its side wall; a filter screen is installed in the flow hole, and the lower end of the flexible sealing sleeve is sealed to the upper part of the cylindrical shell; The scaling box is located inside a cylindrical shell and includes an outer shell, a fixed shaft, and a coil spring. The outer shell is fixed inside the cylindrical shell, the fixed shaft is fixed inside the outer shell, and the coil spring is wound around the fixed shaft, with one end fixed to the fixed shaft and the other end connected to a cable. The cable passes through the top of the flexible sealing sleeve, and the two are sealed and fixedly connected at their intersection. One end of the safety cable is fixedly connected to a gravity anchor, and the other end is fixedly connected to the cable on the upper side of the flexible sealing sleeve. The length of the safety cable is slightly less than the length of the fully expanded sealing cover.

[0007] Preferably, the upper part of the outer wall of the cylindrical shell is provided with two annular grooves, and the flexible sealing sleeve is tightly fixed to the cylindrical shell at the annular grooves by a clamp.

[0008] Preferably, the flexible sealing sleeve is made of waterproof, corrosion-resistant, high-strength PVC knife-coated cloth, and is folded into a cylindrical shape, folding and unfolding in accordance with the scaling of the cable.

[0009] Preferably, the cable inside the flexible sealing sleeve is provided with a buffer assembly, which includes an upper connecting rope, a lower connecting rope, an outer tube and an inner tube arranged coaxially. The upper end of the outer tube is sealed and the lower end is open; the lower end of the inner tube is sealed and the upper end is open, and the inner tube passes through and is fixed to the top plate of the outer tube; a large piston is slidably installed in the annulus between the outer tube and the inner tube, and multiple retractable flexible watertight tubes are evenly distributed between the large piston and the top plate of the outer tube. Multiple upper connecting ropes pass through a flexible watertight tube respectively, and their lower ends are all fixed to the large piston, and their upper ends converge and are fixed to the lower end of the upper cable; a small piston is slidably installed inside the inner tube, and a flexible watertight tube is also connected between the small piston and the bottom plate of the inner tube. The lower connecting rope passes through the flexible watertight tube, and its upper end is fixed to the small piston, and its lower end is fixedly connected to the upper end of the lower cable; The lower part of the annular inner wall of the outer tube and the inner tube is provided with a first upper limit position and a first lower limit position to control the stroke of the large piston. The first lower limit position is located at the lower end of the annular inner wall of the outer tube and the inner tube. The upper part of the inner wall of the inner tube is provided with a second upper limit position and a second lower limit position to control the stroke of the small piston. The second upper limit position is located at the upper end of the inner wall of the inner tube. The second lower limit position is located above the first upper limit position. Several through holes are opened on the inner tube wall between the two.

[0010] Preferably, the inner cavity of the outer tube and the inner cavity of the inner tube are connected by a through hole to form a sealed connecting cavity, which is filled with clean water.

[0011] Preferably, the cable, upper connecting rope, and lower connecting rope are all polyamide ropes, and the outer tube and inner tube are both ultra-high molecular weight polyethylene pipes.

[0012] Preferably, it also includes a grid base, which is fixedly installed at the bottom of the gravity anchor.

[0013] Compared with the prior art, the present invention has the following advantages: This device can automatically adjust the cable length based on changes in water level without the need for electricity, using a purely mechanical structure. The grid base increases the base area to prevent overturning and slippage, and also acts as an anti-erosion measure, making it suitable for anchoring in easily slippery underwater environments such as mud and sand. The buffer component is a communicating vessel designed using Pascal's isobaric transmission principle, which can buffer the instantaneous external force on the tension spring, ensuring the normal operation of the spring. It is this buffer design and its cooperation with the spring that enables safe and stable automatic adjustment of the cable length by large ranges, even several meters. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a schematic diagram showing the state of the coil spring when it is relaxed. Figure 3 This is a schematic diagram of the buffer component. Figure 4 This is a schematic diagram showing the state of the coil spring when it is tensioned.

[0015] In the diagram: 1. Flexible sealing sleeve, 2. Cylindrical shell, 3. Filter screen, 4. Cable, 5. Gravity anchor, 6. Grid base, 7. Safety cable, 8. Outer shell, 9. Fixed shaft, 10. Coil spring, 11. Outer tube, 12. Inner tube, 1201. Through hole, 13. Large piston, 14. Flexible watertight pipe, 15. Upper connecting rope, 16. First upper limit, 17. First lower limit, 18. Small piston, 19. Lower connecting rope, 20. Second upper limit, 21. Second lower limit. Detailed Implementation

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments. Example 1

[0017] Reference Figure 1As shown, a gravity anchor 5 for automatically and significantly adjusting the length of the cable 4 includes a gravity anchor 5, a cable 4, a sealing cover, a scaling box, and a safety cable 7. The sealing cover includes a flexible sealing sleeve 1 and a cylindrical shell 2. The cylindrical shell 2 is fixed to the gravity anchor 5 by bolts, and has flow holes on its side wall. A filter screen 3 is installed inside the flow holes. When the cable 4 scales up and down, seawater is squeezed out through the filter screen 3 and enters the sealing cover, ensuring a clean water environment inside the sealing cover. The lower end of the flexible sealing sleeve 1 is fitted onto the upper part of the cylindrical shell 2.

[0018] The scaling box is located inside the cylindrical shell 2, and includes an outer shell 8, a fixed shaft 9, and a coil spring 10. The outer shell 8 is fixed inside the cylindrical shell 2, the fixed shaft 9 is fixed inside the outer shell 8, and the coil spring 10 is wound around the fixed shaft 9. One end of the coil spring 10 is fixed to the fixed shaft 9, and the other end is connected to the cable 4. The cable 4 passes through the top of the flexible sealing sleeve 1, and the two are sealed and fixedly connected at the intersection. One end of the safety cable 7 is fixedly connected to the gravity anchor 5, and the other end is fixedly connected to the cable 4 on the upper side of the flexible sealing sleeve 1. The length of the safety cable 7 is slightly less than the length of the fully extended sealing sleeve, ensuring that the entire cable 4 automatic scaling system is not damaged.

[0019] During implementation, first connect the floating structure on the water surface to the upper end of the cable 4, and then use lifting equipment to lift the gravity anchor 5 and place it at the target position on the bottom of the water.

[0020] When the water level rises, the upper end of the mooring cable 4 is stretched, and the flexible sealing cover extends accordingly. At the same time, the coil spring 10, which is pre-wound and stored in the scaling box, is tightened, and the pre-stored length is released, so that the length of the mooring cable 4 can be automatically extended to several meters.

[0021] When the water level drops, the distance between the floating body and the gravity anchor 5 shortens, the mooring cable 4 loosens, and the coil spring 10 rotates under the action of the rebound force, and is wound back into the shrink box, in a relaxed state.

[0022] When large waves cause the surface float to shift horizontally, the device operates in the same manner as when the water level rises. If the safety cable 7 is straightened, the mooring length cannot be increased further. When the waves weaken, the surface float will return to the vicinity of the mooring device under the rebound force of the coil spring 10, at which point the device returns to normal operation. Example 2

[0023] As a preferred embodiment of the present invention, this embodiment adds a buffer component based on embodiment one, specifically as follows: Reference Figure 2-4As shown, in this embodiment, a buffer assembly is provided on the cable 4 inside the flexible sealing sleeve 1. The buffer assembly includes an upper connecting rope 15, a lower connecting rope 19, an outer tube 11 and an inner tube 12 arranged coaxially. The upper end of the outer tube 11 is sealed and the lower end is open; the lower end of the inner tube 12 is sealed and the upper end is open. The inner tube 12 passes through and is fixed to the top plate of the outer tube 11. A large piston 13 is slidably installed in the annulus between the outer tube 11 and the inner tube 12. Eight pistons are evenly distributed between the large piston 13 and the top plate of the outer tube 11. A flexible, watertight tube 14 is retractable. Eight upper connecting ropes 15 pass through one flexible, watertight tube 14, and their lower ends are all fixed to the large piston 13. Their upper ends converge and are fixed to the lower end of the upper cable 4. A small piston 18 is slidably installed inside the inner tube 12. A flexible, watertight tube 14 is also connected between the small piston 18 and the bottom plate of the inner tube 12. A lower connecting rope 19 passes through the flexible, watertight tube 14, and its upper end is fixed to the small piston 18. Its lower end is fixedly connected to the upper end of the lower cable 4.

[0024] The lower part of the annular inner wall of the outer tube 11 and the inner tube 12 is provided with a first upper limit position 16 and a first lower limit position 17 to control the stroke of the large piston 13. The first lower limit position 17 is located at the lower end of the annular inner wall of the outer tube 11 and the inner tube 12. The upper part of the inner wall of the inner tube 12 is provided with a second upper limit position 20 and a second lower limit position 21 to control the stroke of the small piston 18. The second upper limit position 20 is located at the upper end of the inner wall of the inner tube 12; the second lower limit position 21 is located above the first upper limit position 16. Several through holes 1201 are opened on the inner wall of the inner tube 12 between the two. The inner cavity of the outer tube 11 and the inner cavity of the inner tube 12 are connected through the through holes 1201 to form a sealed connecting cavity, which is filled with clean water.

[0025] More specifically, cable 4, upper connecting rope 15 and lower connecting rope 19 are all polyamide ropes, and outer tube 11 and inner tube 12 are both ultra-high molecular weight polyethylene pipes.

[0026] (1) When the water level rises, the mooring pull of the floating body is transmitted to the eight upper connecting ropes 15 through the cable 4. The upper connecting ropes 15 pull the large piston 13 upward, and at the same time, the flexible watertight tube 14 is shortened, which reduces the volume of the inner cavity of the outer tube 11. The water in the cavity enters the inner cavity of the inner tube 12 through the through hole 1201 on the wall of the inner tube 12, and then pushes the small piston 18 upward. Before the small piston 18 reaches the second upper limit 20, the force pushing the small piston 18 is greatly reduced by the hydraulic transmission between the inner cavity of the outer tube 11 and the inner cavity of the inner tube 12 according to the difference in cross-sectional area of ​​the large and small chambers (using the hydraulic transmission principle, since the cross-sectional area of ​​the large piston 13 is larger than that of the small piston 18, the mooring force of the floating body is greatly reduced and transmitted to the coil spring 10). This smaller pre-tension force is continued to be transmitted by the small piston 18 through the lower connecting rope 19 as the force to pull out the coil spring 10. In this way, the pre-wound spring 10 stored in the scaling box is tightened, the pre-stored length is released, and the folded layer of the flexible sealing sleeve 1 is stretched, enabling the mooring cable 4 to automatically extend in length by several meters. This relatively small pre-tension ensures the safe operation of the spring 10. The movement of the large piston 13 and the small piston 18 is minimal; the primary function is for the spring 10 to be pulled out to increase the length of the mooring cable 4. Simultaneously, the safety cable 7 is also pulled up. If the safety cable 7 is taut, the mooring length cannot be increased further. Thus, the length of the mooring cable 4 is automatically, continuously, and significantly increased, even by several meters, ensuring the safe buoyancy of the floating structure as the water level rises.

[0027] (2) When the water level changes from high to low, the distance between the floating body on the water surface and the gravity anchor 5 shortens, the mooring cable 4 loosens, and the coil spring 10 rotates under the action of the rebound force and is wound back into the zoom box, in a relaxed state.

[0028] (3) In both of the above situations, if a huge fluid load acts on the floating body on the water surface, the buffer assembly will buffer the strong fluid load, ensure the safety of the floating body, and extend the life of the floating body. At this time, the cable 4 is stretched, and its working state is consistent with that when the water level changes from low to high.

[0029] The buffer component is a communicating vessel designed using Pascal's isobaric transmission principle, which can buffer the instantaneous external force on the tension spring 10 and ensure the normal operation of the spring 10. It is this buffer design and its cooperation with the spring 10 that enables the safe and stable automatic large-scale adjustment of the cable 4 length, even by several meters. Example 3

[0030] As a preferred embodiment of the present invention, this embodiment adds a grid base 6 based on embodiment one, specifically: This embodiment also includes a grid base 6, which is fixedly installed at the bottom of the gravity anchor 5. The grid base 6 is used to prevent the seabed sediment foundation of the gravity anchor 5 from being hollowed out and to prevent the gravity anchor 5 from slipping or overturning. Example 4

[0031] In this embodiment, the upper part of the outer wall of the cylindrical shell 2 is provided with two annular grooves, which can be used to tightly fix the flexible sealing sleeve 1 and the cylindrical shell 2 at the grooves to achieve a sealing effect. Example 5

[0032] In this embodiment, the flexible sealing sleeve 1 is made of waterproof, corrosion-resistant, high-strength PVC knife-coated cloth and is folded into a cylindrical shape. It folds and unfolds in accordance with the scaling of the cable 4, and together they play the role of automatically scaling the tension cable 4.

[0033] In summary, this device can automatically adjust the length of cable 4 based on changes in water level without the need for electricity, using a purely mechanical structure. The grid base 6 increases the base area to prevent overturning and slippage, and also acts as an anti-erosion agent, making it suitable for anchoring in easily slippery underwater environments such as mud and sand. The buffer component is a communicating vessel designed using Pascal's isobaric transmission principle, which can buffer the instantaneous external force of the tension spring 10, ensuring the normal operation of the spring 10. It is precisely this buffer design and its cooperation with the spring 10 that enables the safe and stable automatic adjustment of the length of cable 4 by a large margin or even several meters.

[0034] This invention is not limited to the embodiments described above. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this invention, and the changed content still falls within the protection scope of this invention.

Claims

1. A gravity anchor for automatically and significantly adjusting the length of a cable, comprising a gravity anchor and a cable, characterized in that: It also includes a sealing cover, a scaling box, and a safety cable. The sealing cover includes a flexible sealing sleeve and a cylindrical shell. The cylindrical shell is mounted on a gravity anchor and has flow holes on its side wall. A filter screen is installed inside the flow holes. The lower end of the flexible sealing sleeve is fitted onto the upper part of the cylindrical shell. The scaling box is located inside a cylindrical shell and includes an outer shell, a fixed shaft, and a coil spring. The outer shell is fixed inside the cylindrical shell, the fixed shaft is fixed inside the outer shell, and the coil spring is wound around the fixed shaft, with one end fixed to the fixed shaft and the other end connected to a cable. The cable passes through the top of the flexible sealing sleeve, and the two are sealed and fixedly connected at their intersection. One end of the safety cable is fixedly connected to a gravity anchor, and the other end is fixedly connected to the cable on the upper side of the flexible sealing sleeve. The length of the safety cable is slightly less than the length of the fully expanded sealing cover.

2. The gravity anchor for automatically and significantly adjusting the cable length according to claim 1, characterized in that: The upper part of the outer wall of the cylindrical shell is provided with two circular grooves, and the flexible sealing sleeve is tightly fixed to the cylindrical shell at the circular grooves by a clamp.

3. The gravity anchor for automatically and significantly adjusting the cable length according to claim 1, characterized in that: The flexible sealing sleeve is made of waterproof, corrosion-resistant, high-strength PVC knife-coated cloth and is folded into a cylindrical shape, folding and unfolding in accordance with the expansion and contraction of the cable.

4. A gravity anchor for automatically and significantly adjusting the length of a cable according to claim 1, characterized in that: A buffer assembly is provided on the cable inside the flexible sealing sleeve. The buffer assembly includes an upper connecting rope, a lower connecting rope, an outer tube and an inner tube arranged coaxially. The upper end of the outer tube is sealed and the lower end is open. The lower end of the inner tube is sealed and the upper end is open. The inner tube passes through and is fixed to the top plate of the outer tube. A large piston is slidably installed in the annulus between the outer tube and the inner tube. Multiple retractable flexible watertight tubes are evenly distributed between the large piston and the top plate of the outer tube. Multiple upper connecting ropes pass through a flexible watertight tube, and their lower ends are all fixed to the large piston. Their upper ends converge and are fixed to the lower end of the upper cable. A small piston is slidably installed inside the inner tube. A flexible watertight tube is also connected between the small piston and the bottom plate of the inner tube. The lower connecting rope passes through the flexible watertight tube, and its upper end is fixed to the small piston. Its lower end is fixedly connected to the upper end of the lower cable. The lower part of the annular inner wall of the outer tube and the inner tube is provided with a first upper limit position and a first lower limit position to control the stroke of the large piston. The first lower limit position is located at the lower end of the annular inner wall of the outer tube and the inner tube. The upper part of the inner wall of the inner tube is provided with a second upper limit position and a second lower limit position to control the stroke of the small piston. The second upper limit position is located at the upper end of the inner wall of the inner tube. The second lower limit position is located above the first upper limit position. Several through holes are opened on the inner tube wall between the two.

5. A gravity anchor for automatically adjusting the length of a cable according to claim 4, characterized in that: The inner cavity of the outer tube and the inner cavity of the inner tube are connected by a through hole to form a sealed connecting cavity, which is filled with clean water.

6. A gravity anchor for automatically and significantly adjusting the length of a cable according to claim 4, characterized in that: The cable, upper connecting rope, and lower connecting rope are all polyamide ropes.

7. A gravity anchor for automatically and significantly adjusting the cable length according to claim 4, characterized in that: Both the outer and inner pipes are made of ultra-high molecular weight polyethylene.

8. A gravity anchor for automatically and significantly adjusting the length of a cable according to claim 1, characterized in that: It also includes a grid base, which is fixedly installed at the bottom of the gravity anchor.

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