A ship gangway carrying chain and carrying cable winding device and winding method

Abstract

The present application relates to a kind of marine springboard bearing chain and bearing cable retraction device and retraction method, including bearing guide device, bearing guide device includes bearing wheel and bearing eye plate, bearing chain cable is wound and arranged on bearing wheel, springboard end eye plate is provided on both sides of springboard, and shackle is provided on springboard end eye plate, one end of bearing chain cable is connected with shackle, the other end is connected with bearing eye plate by passing through bearing wheel and traction device, traction device is provided with traction cable, traction device is connected with winch by traction cable, to make bearing chain cable slide to bow or stern direction;It solves the problem that operator cannot complete artificial binding and fixing, arrangement etc. due to bearing chain and bearing cable, when closing lifting springboard, avoid that bearing chain and bearing cable are stuck to cause springboard cannot be normally closed or damaged;When opening and lowering springboard, release bearing chain and bearing cable and keep bearing chain and bearing cable appropriate slack, avoid that device bears additional load when springboard is lowered and is damaged.

Description

Technical Field

[0001] This invention relates to the field of ship design technology, and in particular to a device and method for launching and retracting a shipboard gangway load-bearing chain and load-bearing cable. Background Technology

[0002] Ro-Ro ships, special-operation vessels, or offshore structures can be classified into single-section ramps and multi-section ramps according to their structural type; and into types according to the transmission device that performs the opening, lowering / closing, and lifting of the ramp, such as direct hydraulic cylinder drive, hydraulic cylinder-linkage drive, hydraulic cylinder-pulley block-wire rope drive, and hydraulic / electric winch-pulley block-wire rope drive.

[0003] During the opening, lowering / closing, and lifting operations of the gangplank, the transmission mechanism must withstand the gangplank's own weight, the ship's static tilting force, the inertial force generated by the ship's movement, and the clamping force of the sealing rubber (only for gangplanks with watertightness requirements in the closed position, and when the gangplank is in the closed position). When the gangplank is fully extended and rests on a dock or other supporting structure, the transmission mechanism no longer bears the gangplank's own weight, the ship's static tilting force, the inertial force generated by the ship's movement, vehicle or cargo loads, and wave loads acting on the gangplank; these loads are then borne by the dock or other supporting structure and the gangplank end hinges (connected to the hull). However, some gangplanks, when extended to their working position at sea, have no dock or other supporting structure to rest on. If supported by the transmission mechanism itself, then during operation after the gangplank is fully extended, the transmission mechanism must withstand the gangplank's own weight, the ship's static tilting force, the inertial force generated by the ship's movement, vehicle or cargo loads, and wave loads acting on the gangplank. In most cases, the load during the operation of the gangway is much greater than the load during operation. If the transmission device needs to bear the load during the gangway's operation, it would be too large and consume too many overall resources. To solve this problem, some transmission devices that use hydraulic cylinders / winches-pulley blocks-wire rope drives can, when overall conditions permit, replace a section of the wire rope connected to the gangway with a chain. When the gangway is opened and lowered into place, the chain is stopped by the gate chain stopper. The load borne by the gangway is transmitted to the gate chain stopper through the chain, and then from the gate chain stopper to the hull structure. The wire rope, hydraulic cylinders / winches, and other transmission devices connected to the chain no longer bear the load, thus simplifying the transmission device. This method is mainly used in single-section gangways or the first section of multi-section gangways.

[0004] In most cases, a separate load-bearing device (also called a "safety device") is installed outside the transmission mechanism, such as a load-bearing chain (also called a "safety chain"), a load-bearing cable (also called a "safety cable"), or a load-bearing linkage (also called a "safety linkage"). The load-bearing device can be configured with an adjustable length range to adapt to different ramp slopes. However, load-bearing devices with adjustable length ranges are complex in mechanism and inconvenient to adjust. Therefore, load-bearing devices with a fixed length range are mostly used, suitable for specific ramp slopes. Load-bearing linkages are inconvenient to operate, easily damaged by vehicles during use, and difficult to open or close after deformation. Therefore, load-bearing chains or load-bearing cables are more commonly used.

[0005] During and after the gangplank closure, the actual state of the load-bearing cable is related to its flexibility, stiffness, and loose length. Flexibility and stiffness are primarily determined by the wire rope diameter, the diameter of the individual wires, and their strength. Larger wire rope diameters, larger individual wire diameters, and greater wire strength result in lower flexibility and higher stiffness. Loose length is determined by the difference between the distance between the load-bearing cable's fixed point on the hull and the fixed point on the second gangplank section when the gangplank is open, and the distance between these two points when the gangplank is closed. A longer loose length results in greater variability in the load-bearing cable's state.

[0006] When selecting a load-bearing cable, the supporting load of the cable is determined based on factors such as the self-weight load of the gangplank, the static tilting force of the ship, the inertial force generated by the ship's motion, the vehicle load or cargo load, and the wave load acting on the gangplank. Then, the wire rope diameter, tensile strength, and breaking strength are determined according to the supporting load. The greater the vehicle load and the more demanding the external environmental conditions, the greater the supporting load of the cable, and the higher the selected wire rope diameter, tensile strength, and breaking strength, resulting in poorer flexibility and greater stiffness.

[0007] The loose length is related to the overall layout plan. Optimization can make the loose length as short as possible. In addition, the longer the scaffold is deployed, the longer the loose length will be after it is closed.

[0008] For example, when closing the gangway on a Type A vessel, the gangway is first raised to a horizontal, upturned position. The operator climbs onto the gangway and secures the two load-bearing cables together between the two gangway sections with a lashing rope. Then, the gangway is closed in place. When opening the gangway, it is first lowered to a horizontal, upturned position. The operator climbs onto the gangway and unties the lashing rope between the two load-bearing cables between the two gangway sections. Then, the gangway is opened in place. Securely fastening the two load-bearing cables effectively reduces loose length and does not affect the opening and closing of the gangway.

[0009] When closing the gangplank on a Type A vessel, the increased diameter of the wire rope leads to decreased flexibility and increased stiffness. Simultaneously, the increased loose length makes the wire rope difficult to control. Following the standard procedure for handling gangplank load-bearing cables on Type A vessels, tying two load-bearing cables between the two gangplank sections becomes more difficult. After tying, the tying ropes repeatedly break during the gangplank closure process, necessitating replacement with longer and stronger cables. After replacing the tying cables, the load-bearing cables become stuck in the door frame and between the two gangplank sections, preventing normal closure. Conversely, during gangplank opening, the load-bearing cables become stuck in hull structural components and protruding parts of the gangplank, preventing normal opening.

[0010] Considering the chain's good flexibility and almost non-stiffness, the load-bearing cable was replaced with a load-bearing chain of equal strength. After replacing the load-bearing chain, there was no jamming between the gate frame or two sections of the gangway during the closing process. However, during the opening process, jamming still occurred with hull structural components and protruding parts of the gangway. Furthermore, because the weight of a single load-bearing chain is almost twice that of the load-bearing cable, even with 2-3 operators standing between two sections of the gangway, it is impossible to complete the securing. Additionally, due to the concentrated downward weight of the chain, during the opening and closing of the gangway, the load-bearing chain swings and strikes the gangway, bow door, and hull structure, easily damaging components such as hydraulic cylinders and sensors. Summary of the Invention

[0011] To address the problem that the load-bearing chain and cable of a marine gangway can become stuck in the frame, between two gangway sections, on ship structural components, or on protruding parts of the gangway during opening or closing due to factors such as the flexibility, stiffness, loose length, and self-weight of the load-bearing chain and cable, thus preventing normal opening or closing, a device and method for retracting and extending the load-bearing chain and cable of a marine gangway is proposed.

[0012] The technical solution of the present invention is as follows: a ship gangway carrying chain and carrying cable take-up and release device, including a carrying guide device, the carrying guide device including a carrying wheel and a carrying eye plate, the carrying wheel is symmetrically fixed on the ship structure relative to the center line of the ship, the carrying chain cable is wound on the carrying wheel, the carrying wheel guides the carrying chain cable, and the carrying wheel transmits the working load borne by the carrying chain cable to the ship structure;

[0013] The traction device is symmetrically arranged on the deck of the hull relative to the centerline of the hull. The load-bearing eye plate is symmetrically arranged on the deck below the traction device relative to the centerline of the hull. On both sides of the extended end of the second section of the gangway away from the hull, there are gangway end eye plates. Shackles are provided on the gangway end eye plates. One end of the load-bearing chain is connected to the shackle, and the end away from the shackle passes around the load-bearing wheel and the traction device and is connected to the load-bearing eye plate. The load-bearing eye plate fixes the load-bearing chain and transfers the working load borne by the load-bearing chain to the hull structure.

[0014] The traction device is equipped with a traction cable, which is connected to the winch. The winch drives the traction cable to be wound and released synchronously, and the traction cable drives the traction device, causing the load-bearing chain to slide towards the bow or stern of the ship.

[0015] Preferably, the traction device includes a traction bracket and a trolley guide rail. The traction bracket is symmetrically fixed on the hull structure relative to the center line of the hull. Each traction bracket consists of two symmetrical frame sections. The trolley guide rail is fixedly installed on the upper inner side of the two symmetrical frame sections of each traction bracket. A trolley is installed on the trolley guide rail. A guide wheel is installed at one end of the trolley. The load-bearing chain is wound around the guide wheel. The end of the trolley away from the guide wheel is connected to one end of the traction cable. Rollers are provided on both sides of the side of the trolley near the traction cable. The trolley slides within the trolley guide rail via the rollers.

[0016] Preferably, the traction bracket is provided with a traction cable steering pulley on the deck at the end away from the bow. The traction cable steering pulley is symmetrically fixed to the hull structure with respect to the hull centerline. The winch is provided on the deck, located on the inner side of the traction cable steering pulley. The winch includes a drum, which is a double-section drum. The end of the traction cable away from the guide wheel passes around the traction cable steering pulley and is wound on the drum. The vertical centerline of the drum coincides with the vertical centerline of the hull.

[0017] Preferably, the traction cable is equipped with a length adjuster, which allows the traction cable to be extended and retracted synchronously.

[0018] Preferably, the winch further includes a servo motor that drives the drum to rotate forward or backward. A reduction gearbox is provided between the servo motor and the drum to reduce the output speed of the motor and increase the torque.

[0019] Preferably, the gearbox has an emergency operating handle on its drive shaft, and the emergency operating handle is detachable.

[0020] Preferably, it also includes an electrical control system. The servo motor electrical control systems are connected by cables. The electrical control system includes an electrical control box, a braking resistor box, and a position sensor. The electrical control box is equipped with buttons or knobs and an audible and visual alarm. The buttons or knobs on the electrical control box control the winch to rotate forward or backward. The position sensor is located near both ends of the trolley guide rail.

[0021] A method for retrieving and deploying a shipboard gangway load-bearing chain and load-bearing cable retrieving and deploying device, comprising the following steps:

[0022] When the gangway is opened, the winch releases the traction cable. Under the traction of the load-bearing chain, the trolley slides towards the bow via the guide wheel, releasing the load-bearing chain and maintaining appropriate tension to prevent the winch from being excessively dragged backward by the load-bearing chain and damaged. After the gangway is fully opened, the load-bearing chain is stretched to the load-bearing state, and the load-bearing eye plate and load-bearing wheel transfer the load borne by the load-bearing chain to the hull structure. During the operation of the gangway, the load borne by the load-bearing chain will not be transferred to the winch, thus preventing winch damage.

[0023] When the gangway is closed, the winch retrieves the traction cable, and the pulley, pulled by the traction cable, slides towards the stern via the guide wheel to retrieve the excessively slack load-bearing chain, avoiding interference between the load-bearing chain and the gangway or hull structure. Under the action of the guide wheel at the front of the pulley, the load-bearing chain is stored in the traction bracket. The guide wheel at the front of the pulley acts as a movable pulley, with a travel distance of twice the storage length of the load-bearing chain, saving installation space and reducing the overall resource occupation.

[0024] Furthermore, the operation control mode of the aforementioned release and take-up method has three implementation methods:

[0025] A. "Constant Torque" Control Mode: In this mode, the winch's servo motor maintains a constant output torque for forward rotation. After passing through the reduction gearbox, this torque serves as the driving torque, which, together with the load resistance torque generated by the tension of the traction cable, acts on the drum. When the driving torque equals the load resistance torque, the servo motor stalls, and the drum remains stationary. When the driving torque is greater than the load resistance torque, the servo motor drives the drum to rotate forward, retrieving the traction cable. When the driving torque is less than the load resistance torque, the servo motor is dragged by the drum to rotate in reverse, releasing the traction cable.

[0026] Specifically, the force analysis of the "constant torque" control mode is as follows:

[0027] When the winch operates in "constant torque" control mode, assuming that the inertial forces caused by the ship's motion are not considered, the forces acting on the pulley at any position of the ramp include: the tension applied to the traction cable by the winch; the friction between the pulley and the pulley guide rail; the component of the force along the guide rail caused by the pulley's own weight due to the ship's trim and the tilt of the pulley guide rail; the force acting on the pulley through the guide wheel due to the weight of the carrying chain; and the additional force exerted by the ramp on the carrying chain, which acts on the pulley through the guide wheel.

[0028] In constant torque control mode, the winch will release the traction cable, and the traction cable will move along the traction cable towards the bow. This is because the tension applied to the traction cable by the winch is less than the friction between the traction cable and the traction cable guide rail, the component of the traction cable's own weight along the guide rail, the force exerted on the traction cable by the weight of the carrying chain cable through the guide wheel, and the additional force exerted by the gangplank on the carrying chain cable. When the combined force of the forces acting on the trolley and the additional force exerted by the ramp on the carrying chain is equal to the force of the additional force exerted by the ramp on the carrying chain, the winch will recover the traction cable in the "constant torque" control mode, and the trolley will move along the trolley guide rail towards the stern. When the tension applied by the winch on the traction cable is equal to the combined force of the friction between the trolley and the trolley guide rail, the component force along the guide rail generated by the trolley's own weight, the force exerted by the carrying chain's own weight on the trolley through the guide wheel, and the additional force exerted by the ramp on the carrying chain, the trolley is in a state of force equilibrium under the action of the above forces and remains in that position.

[0029] When the gangplank is lowered, it descends under its own weight. The gangplank deployment and retraction device supports the gangplank's weight and controls its descent speed. During the lowering process, due to the increased additional force exerted by the gangplank on the load-bearing chain and the increased force exerted by the load-bearing chain's own weight on the pulley through the guide wheels, the tension applied to the traction cable by the winch is less than the combined force of the friction between the pulley and the pulley rail, the component force along the rail generated by the pulley's own weight, the force exerted by the load-bearing chain's own weight on the pulley through the guide wheels, and the additional force exerted by the gangplank on the load-bearing chain. In the "constant torque" control mode, the winch releases the traction cable, and the pulley and its fixed guide wheels move along the pulley rail towards the bow. The load-bearing chain guided by the guide wheels is released and lowered along with the gangplank until the gangplank is fully deployed.

[0030] B. "Retract and Release" Control Mode: This is the normal winch control mode. The winch's servo motor is used as a regular motor. The operator operates the buttons or knobs on the electrical control box to make the winch rotate forward or backward, and to retract or release the traction cable.

[0031] C. "Manual Emergency" Operation Mode: When the device loses power or the electrical control system malfunctions, the electromagnetic brake of the servo motor is released, and the drive shaft of the gearbox is directly rotated by shaking the emergency operation handle, so that the drum can be manually driven to wind up and unwind the traction cable.

[0032] Furthermore, the shipboard gangway support chain and support cable deployment and retraction device can be independently installed outside the gangway's control system and controlled independently through the electrical control system, or it can be jointly controlled with the gangway.

[0033] When controlled independently, the shipboard gangway support chain and support cable retraction device does not have an interlocking function with the gangway. The winch can be operated and controlled independently in the "retraction" working mode, "constant torque" working mode or "manual emergency" operation mode.

[0034] During joint control, the winch automatically switches to the "constant torque" working mode, and the shipboard ramp support chain and support cable take-up and release device are linked with the ramp, which has an interlocking function with the ramp.

[0035] The beneficial effects of this invention are as follows: This invention provides a device for retracting and extending a ship's gangway support chain and cable, solving the problem that operators cannot manually tie and secure the support chain and cable due to their flexibility, stiffness, loose length, and weight. When closing the gangway, the device retracts the slack support chain and cable while maintaining appropriate tension, preventing them from getting stuck in the frame, between two gangway sections, on hull structural components, or on protruding parts of the gangway, thus avoiding damage to the gangway, support chain and cable, gangway, or hull structure. When opening and lowering the gangway, the device releases the support chain and cable while maintaining appropriate slack, preventing damage caused by excessive additional load during gangway lowering.

[0036] This invention provides a method for the release and retrieval of a shipboard gangway support chain and support cable. By using the winch's "constant torque" working mode, the release or retrieval of the support chain and support cable is linked with the opening, lowering, closing, and lifting of the gangway. During the operation, the support chain and support cable are kept appropriately slack or tensile, reducing the risk of difficulty for operators to control the tension or slack of the support chain and support cable by observation when the winch is in the "release and retrieval" working mode. Attached Figure Description

[0037] Figure 1 This is a front view schematic diagram of the shipboard gangway support chain and support cable deployment and retraction device of the present invention in the gangway deployment state;

[0038] Figure 2 This is a front view schematic diagram of the shipboard gangway support chain and support cable deployment and retraction device of the present invention in the gangway closed state;

[0039] Figure 3 This is a top view of the shipboard gangway support chain and support cable deployment and retraction device of the present invention in the gangway deployment state;

[0040] Figure 4 This is a top view schematic diagram of the installation of the load-bearing chain of the present invention;

[0041] Figure 5 This is a schematic front view of the traction device of the present invention;

[0042] Figure 6 This is a schematic diagram of the traction bracket of the present invention from the left.

[0043] Figure 7 This is a top view of the trolley of the present invention;

[0044] Figure 8 This is a schematic diagram of the traction cable installation on the traction cable steering pulley of the present invention;

[0045] Figure 9 This is a schematic diagram showing the connection between the winch and the steering pulley of the traction cable in this invention;

[0046] Figure 10 This is a schematic diagram of the winch of the present invention;

[0047] Figure 11 This is a top view schematic diagram of the winch of the present invention;

[0048] Figure 12 This is a schematic diagram of the electrical control box of the present invention;

[0049] Figure 13 This is a schematic diagram of the forces acting on the trolley of the present invention, wherein (a) is a force diagram of the trolley, (b) is a force diagram of the trolley in the state of opening the ramp, and (c) is a force diagram of the trolley in the state of closing the ramp.

[0050] The component names corresponding to the various reference numerals in the diagram are as follows:

[0051] 1. Load-bearing guide device; 11. Load-bearing wheel; 12. Load-bearing eye plate; 2. Traction device; 21. Traction bracket; 22. Trolley guide rail; 23. Trolley; 231. Roller; 24. Guide wheel; 25. Traction cable; 251. Length adjuster; 26. Traction cable steering pulley; 3. Winch; 31. Servo motor; 32. Gearbox; 33. Drum; 34. Emergency operating handle; 4. Electrical control system; 41. Electrical control box; 411. Knob; 412. Automatic mode button; 413. Manual mode button; 414. Audible and visual alarm; 415. Emergency stop button; 42. Position sensor; 5. Load-bearing chain; 6. Shackle; 7. Plane end eye plate; 8. Plane deployment and retraction device. Detailed Implementation

[0052] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0053] refer to Figure 1 , 4As shown, the present invention provides a shipboard gangway support chain and support cable deployment and deployment device, including a support guide device 1, a traction device 2, a winch 3, an electrical control system 4, and a support chain cable 5. The support guide device 1 includes a support wheel 11 and a support eye plate 12. The support wheel 11 is symmetrically fixed to the hull structure above the bow plate relative to the hull centerline. The support chain cable 5 is wound around the support wheel 11. If the support chain cable 5 uses a chain as the support chain, the support wheel 11 is a support sprocket; if the support chain cable 5 uses a wire rope as the support cable, the support wheel 11 is a support pulley. The support wheel 11 serves to guide the support chain cable 5 and transfer the working load borne by the support chain cable 5 to the hull structure.

[0054] The towing device 2 is symmetrically arranged on the deck of the hull relative to the hull centerline, and the bearing plate 12 is symmetrically arranged on the deck below the towing device 2 relative to the hull centerline, as shown below. Figure 3 As shown, on both sides of the extended end of the second gangway away from the hull, gangway end eye plates 7 are provided. Shackles 6 are provided on the gangway end eye plates 7. One end of the load-bearing chain 5 is connected to the shackles 6, and the other end away from the shackles 6 is connected to the load-bearing eye plate 12. The load-bearing eye plate 12 serves to fix the load-bearing chain 5 on the one hand, and transfer the working load borne by the load-bearing chain 5 to the hull structure on the other hand.

[0055] Once the gangplank is opened and lowered to the working position, the external loads acting on the gangplank, such as vehicle load, wave load, climate load, and inertial force caused by ship movement, as well as the gangplank's own weight, are borne by the load-bearing chain 5 and transmitted to the ship structure through the load-bearing eye plate 12 and the load-bearing wheel 11.

[0056] refer to Figure 5 , 6 As shown, the traction device 2 includes a traction bracket 21, a trolley guide rail 22, a trolley 23, a guide wheel 24, a traction cable 25, and a traction cable steering pulley 26. If the load-bearing chain 5 uses a chain as the load-bearing chain, the guide wheel 24 is a guide sprocket; if the load-bearing chain 5 uses a wire rope as the load-bearing cable, the guide wheel 24 is a guide pulley. The guide wheel 24 acts as a movable pulley, with a travel distance of twice the stored length of the load-bearing chain 5, saving installation space and reducing the overall resource occupation. The traction bracket 21 is symmetrically fixed on the hull structure relative to the hull centerline. Each traction bracket 21 consists of two symmetrical frame sections, and the trolley guide rail 22 is fixedly installed on the upper inner side of the two symmetrical frame sections of each traction bracket 21.

[0057] refer to Figure 5 , 7As shown, a trolley 23 is provided on the trolley guide rail 22. A guide wheel 24 is provided at one end of the trolley 23. The load-bearing chain 5 is wound around the guide wheel 24. The end of the trolley 23 away from the guide wheel 24 is connected to one end of the traction cable 25. Rollers 231 are provided on both sides of the side of the trolley 23 near the traction cable 25. The trolley 23 slides in the trolley guide rail 22 through the rollers 231.

[0058] One end of the load-bearing chain 5 is connected to the shackle 6, and the end away from the shackle 6 passes around the load-bearing wheel 11 and the guide wheel 24 at the front end of the trolley 23 and is connected and fixed to the load-bearing eye plate 12. When the gangplank is closed, the trolley 23 drives the load-bearing chain 5 to move along the trolley guide rail 22 towards the stern. The excess load-bearing chain 5 is stored in the traction bracket 21. The load-bearing chain 5 passes around the load-bearing wheel 11 and is stretched to the load-bearing state at the load-bearing eye plate 12 at the hull end and the gangplank end eye plate 7. The external loads acting on the gangplank, such as vehicle loads or cargo loads, wave loads, weather loads, inertial forces caused by ship motion, and the gangplank's own weight load, are borne by the load-bearing chain 5 and are transferred to the hull structure through the load-bearing eye plate 12 and the load-bearing wheel 11. During the operation of the gangplank, the load borne by the load-bearing chain 5 will not be transferred to the winch 3, thus preventing damage to the winch 3.

[0059] refer to Figure 8 , 9 As shown, a traction cable steering pulley 26 is provided on the deck at the end of the traction bracket 21 away from the bow. The traction cable steering pulley 26 is symmetrically fixed to the hull structure relative to the hull centerline. The winch 3 includes a drum 33, which is set on the deck and located on the inner side of the traction cable steering pulley 26. The vertical centerline of the drum 33 coincides with the vertical centerline of the hull. The drum 33 is a double-section drum. One double-section drum winch 3 realizes the function of two single-section drum winches, saving costs and overall resources.

[0060] refer to Figure 10 , 11 As shown, the winch 3 also includes a servo motor 31, a gearbox 32, and an emergency operating handle 34. The end of the traction cable 25 away from the guide wheel 24 is wound around the traction cable guide pulley 26 and onto the drum 33. Figure 3 As shown, the traction cable 25 is equipped with a length adjuster 251, which can ensure that the two traction cables 25 are wound and unwound synchronously. The servo motor 31 drives the drum 33 to rotate forward or backward. A reduction gearbox 32 is provided between the servo motor 31 and the drum 33. The reduction gearbox 32 reduces the output speed of the motor and increases the torque, which is suitable for occasions that require high torque and low speed rotation.

[0061] The winch 3 is connected to the trolley 23 via the traction cable steering pulley 26 and the traction cable 25. The winch 3 drives the trolley 23 to slide within the trolley guide rail 22 by winding and unwinding the traction cable 25. The emergency operating handle 34 is detachable and is temporarily installed on the drive shaft of the gearbox 32 during use. In the event of power failure or electrical control system failure, the drive shaft of the winch gearbox 32 can be directly rotated through the emergency operating handle 34 to manually drive the drum to wind and unwind the traction cable, thereby releasing or recovering the carrying chain 5.

[0062] refer to Figure 5 , 12 As shown, the electrical control system 4 includes an electrical control box 41 and a position sensor 42; the servo motor 31 is connected to the electrical control system 4 via a cable; the winch power is turned on or off by the knob 411 on the electrical control box 41. After turning on the power, pressing the automatic mode button 412 enables automatic winding and unwinding of the load-bearing chain 5 in "constant torque mode," or operating the manual mode button 413 enables winding and unwinding of the load-bearing chain 5 in "manual mode." The manual mode button 413 includes two buttons: "lower" and "upper." Pressing the "lower" button causes the winch to rotate forward and release the load-bearing chain 5; pressing the "upper" button causes the winch to rotate backward and retract the load-bearing chain 5. The electrical control box 41 is equipped with an audible and visual alarm 414, which sounds an alarm when the device malfunctions. The position sensor 42 is located near both ends of the trolley guide rail 22. The position sensor 42 detects the specific position of the trolley 23. In the "constant torque mode", when the position sensor 42 is triggered, the winch power is disconnected and the carrying chain 5 is wound up or down into place. The electrical control box 41 is equipped with an emergency stop button 415. When the ramp or winch malfunctions, pressing the emergency stop button 415 shuts off the power to the electrical control system. The control room is equipped with a braking resistor box, which is used to control the braking of the winch motor to prevent the winch motor speed from being too high.

[0063] The method for retrieving and deploying the load-bearing chain and load-bearing cable of the marine gangway as described above comprises the following steps:

[0064] When the gangway is opened, the winch 3 releases the traction cable 25. Under the traction of the load-bearing chain cable 5, the pulley 23 drives the load-bearing chain cable 5 to slide towards the bow through the guide wheel 24, releasing the load-bearing chain cable 5 and maintaining appropriate tension to prevent the winch 3 from being excessively dragged backward by the load-bearing chain cable 5 and damaged. After the gangway is opened to the correct position, the load-bearing chain cable 5 is stretched to the load-bearing state, and the load-bearing eye plate 12 and the load-bearing wheel 11 transfer the load borne by the load-bearing chain cable 5 to the hull structure. During the operation of the gangway, the load borne by the load-bearing chain cable 5 will not be transferred to the winch 3, thus preventing damage to the winch 3.

[0065] When the gangway is closed, winch 3 retracts the traction cable 25. Under the traction of the traction cable 25, pulley 23 drives the load-bearing chain 5 to slide towards the stern via guide wheel 24, retracting the excessively slack load-bearing chain 5 and preventing interference between the load-bearing chain 5 and the gangway or hull structure. Under the action of guide wheel 24 at the front of pulley 23, the load-bearing chain 5 is stored in the traction bracket 21. The guide wheel 24 at the front of pulley 23 acts as a movable pulley, with a travel distance of twice the storage length of the load-bearing chain 5, saving installation space and reducing the overall resource occupation.

[0066] The method for retracting and extending the marine gangway load-bearing chain and load-bearing cable retracting and extending device includes three operational control modes:

[0067] A. "Constant Torque" Control Mode: (Refer to...) Figure 10 , 11 As shown, in this mode, the servo motor 31 of the winch 3 maintains a constant output torque (Trated) rotating forward. After passing through the reduction gearbox 32 (reduction ratio of i, efficiency of η), it serves as the driving torque (iηTrated), which, together with the load resistance torque (TloadR, where R is the drum radius) generated by the tension (Trope) of the traction cable 25, acts on the drum 33. When iηTrated equals TloadR, the servo motor 31 stalls, and the drum 33 remains stationary. When iηTrated is greater than TloadR, the servo motor 31 drives the drum 33 to rotate forward, retrieving the traction cable 25. When iηTrated is less than TloadR, the servo motor 31 is dragged by the drum 33 to rotate backward, releasing the traction cable 25.

[0068] B. “Retract and Release” Control Mode: This is the normal winch control mode. The servo motor 31 of the winch 3 is used as a normal motor. The operator can make the winch 3 rotate forward or reverse by operating the button 411 or knob 412 on the electrical control box 41 to retract or release the traction cable 25.

[0069] C. "Manual Emergency" Operation Mode: When the device loses power or the electrical control system fails, the electromagnetic brake of the servo motor 31 is released, and the emergency operation handle 34 is cranked to directly rotate the transmission shaft of the gearbox 32, and the drum 33 is manually driven to wind up and unwind the traction cable 25.

[0070] The aforementioned ship gangway support chain and support cable retraction device can be independently installed outside the gangway's control system and controlled independently through the electrical control system 4, or it can be jointly controlled with the gangway. When controlled independently, the ship gangway support chain and support cable retraction device does not have an interlocking function with the gangway, and the winch 3 can be operated and controlled separately in the "retraction" working mode, "constant torque" working mode, or "manual emergency" operating mode. When controlled jointly, the winch 3 automatically switches to the "constant torque" working mode, and the ship gangway support chain and support cable retraction device are linked with the gangway, and have an interlocking function with the gangway, that is, the gangway only starts to move after both the gangway and the winch 3 are started.

[0071] For details, please refer to Figure 13 As shown, the specific force analysis of the "constant torque" control mode is as follows:

[0072] When winch 3 operates in "constant torque" control mode, assuming that the inertial force caused by the ship's motion is not considered, the forces acting on pulley 23 at any position of the ramp include: the tension (Twinch) applied to the traction cable 25 by winch 3; the friction (Ffriction) between pulley 23 and pulley guide rail 22; the component force (Gblock) along the guide rail direction generated by the weight of pulley 23 due to the ship's trim and the tilt of pulley guide rail 22; the force (Gchain) acting on pulley 23 by the weight of the carrying chain 5 through guide wheel 24; and the additional force (Fchain) exerted by the ramp on the carrying chain 5, which acts on pulley 23 through guide wheel 24.

[0073] When Twinch is less than the resultant force of Ffriction, Gblock, Gchain, and Fchain, winch 3 will release the traction cable 25 in the "constant torque" control mode, and trolley 23 will move towards the bow along trolley rail 22; when Twinch is greater than the resultant force of Ffriction, Gblock, Gchain, and Fchain, winch 3 will retract the traction cable 25 in the "constant torque" control mode, and trolley 23 will move towards the stern along trolley rail 22; when Twinch is equal to the resultant force of Ffriction, Gblock, Gchain, and Fchain, trolley 23 will be in a state of force equilibrium under the action of the above forces and will remain in that position.

[0074] When the gangplank is lowered, it descends under its own weight. The gangplank deployment and retraction device 8 supports the gangplank's weight and controls its descent speed. During the lowering process, due to the increase in Fchain and Gchain, the Twinch becomes less than the resultant force of Ffriction, Gblock, Gchain, and Fchain. In the "constant torque" control mode, the winch 3 releases the traction cable 25. The trolley 23 and its fixed guide wheel 24 move along the trolley guide rail 22 towards the bow. The load-bearing chain 5, guided by the guide wheel 24, is released and lowered along with the gangplank until it is fully deployed.

[0075] When the gangplank is closed and retracted, the gangplank rises against its own weight. The gangplank retraction device 8 supports the gangplank's weight and controls its lifting speed. Once the gangplank begins to lift, the load-bearing chain 5 immediately loosens, and the Fchain becomes almost zero. This causes the Twinch to be greater than the combined force of Ffriction, Gblock, Gchain, and Fchain. In the "constant torque" control mode, the winch 3 will retract the traction cable 25. The trolley 23 and the guide wheel 24 fixed on it move along the trolley guide rail 22 towards the stern. The load-bearing chain 5, guided by the guide wheel 24, will be retracted along with the gangplank until the gangplank is closed in place.

[0076] The beneficial effects are as follows: This invention provides a device for retracting and extending a ship's gangway support chain and cable, solving the problem that operators cannot manually tie and secure the support chain and cable due to their flexibility, stiffness, loose length, and weight. When closing the gangway, the device retracts the slack support chain and cable while maintaining appropriate tension, preventing them from getting stuck in the frame, between two gangway sections, on hull structural components, or on protruding parts of the gangway, thus avoiding damage to the gangway, support chain and cable, gangway, or hull structure. When opening and lowering the gangway, the device releases the support chain and cable while maintaining appropriate slack, preventing damage caused by excessive additional load during gangway lowering.

[0077] This invention provides a method for the release and retrieval of a shipboard gangway support chain and support cable. By using the "constant torque" working mode of the winch 3, the release or retrieval of the support chain and support cable is linked with the opening, lowering, closing, and lifting of the gangway. During the operation, the support chain and support cable are kept appropriately slack or tensile, reducing the risk of difficulty for operators to control the tension or slack of the support chain and support cable by observation when the winch is in the "release and retrieval" working mode.

[0078] It should be noted that the terms "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention 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 the present invention. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. "A plurality of" means two or more. "Installed," "connected," and "joined" should be interpreted broadly; for example, it can refer to a fixed connection, a detachable connection, or an integral connection.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any form or substance. It should be noted that those skilled in the art can make various improvements and additions without departing from the present invention, and these improvements and additions should also be considered within the scope of protection of the present invention. Any modifications, alterations, and equivalent changes made by those skilled in the art based on the above-disclosed technical content without departing from the spirit and scope of the present invention are equivalent embodiments of the present invention. Furthermore, any modifications, alterations, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solution of the present invention.

Claims

1. A device for launching and retracting a shipboard gangway support chain and support cable, characterized in that, The system includes a load-bearing guide device (1), which includes a load-bearing wheel (11) and a load-bearing eye plate (12). The load-bearing wheel (11) is symmetrically fixed on the hull structure relative to the center line of the hull. The load-bearing chain (5) is wound around the load-bearing wheel (11). The load-bearing wheel (11) guides the load-bearing chain (5) and transmits the working load borne by the load-bearing chain (5) to the hull structure. The traction device (2) is symmetrically arranged on the deck of the hull relative to the center line of the hull. The load-bearing eye plate (12) is symmetrically arranged on the deck at the bottom of the traction device (2) relative to the center line of the hull. The two sides of the extended end of the second section of the gangway away from the hull are provided with gangway end eye plates (7). Shackles (6) are provided on the gangway end eye plates (7). One end of the load-bearing chain (5) is connected to the shackle (6), and the end away from the shackle (6) passes around the load-bearing wheel (11) and the traction device (2) and is connected to the load-bearing eye plate (12). The load-bearing eye plate (12) fixes the load-bearing chain (5). The load-bearing eye plate (12) transmits the working load borne by the load-bearing chain (5) to the hull structure. The traction device (2) is equipped with a traction cable (25). The traction device (2) is connected to the winch (3) through the traction cable (25). The winch (3) drives the traction cable (25) to be wound and released synchronously. The traction cable (25) drives the traction device (2), causing the carrying chain (5) to slide towards the bow or stern of the ship. The traction device (2) includes a traction bracket (21) and a trolley guide rail (22). The traction bracket (21) is symmetrically fixed on the hull structure relative to the center line of the hull. Each traction bracket (21) is a symmetrical two-section frame. The trolley guide rail (22) is fixedly installed on the upper inner side of the symmetrical two-section frame of each traction bracket (21). A trolley (23) is provided on the trolley guide rail (22). A guide wheel (24) is provided at one end of the trolley (23). The load-bearing chain (5) is wound on the guide wheel (24). The end of the trolley (23) away from the guide wheel (24) is connected to one end of the traction cable (25). Rollers (231) are provided on both sides of the end of the trolley (23) close to the traction cable (25). The trolley (23) slides in the trolley guide rail (22) through the rollers (231). The traction bracket (21) is provided with a traction cable steering pulley (26) on the deck at the end away from the bow. The traction cable steering pulley (26) is fixedly installed on the hull structure symmetrically with respect to the center line of the hull. The winch (3) is installed on the deck and located on the inner side of the traction cable steering pulley (26). The winch (3) includes a drum (33), which is a double-section drum. The end of the traction cable (25) away from the guide wheel (24) passes around the traction cable steering pulley (26) and is wound on the drum (33). The vertical center line of the drum (33) coincides with the vertical center line of the hull.

2. The marine gangway support chain and support cable deployment and retraction device according to claim 1, characterized in that, The traction cable (25) is equipped with a length adjuster (251), which allows the traction cable (25) to be extended and retracted synchronously.

3. The marine gangway support chain and support cable deployment and retraction device according to claim 1, characterized in that, The winch (3) also includes a servo motor (31), which drives the drum (33) to rotate forward or backward. A reduction gearbox (32) is provided between the servo motor (31) and the drum (33), which reduces the output speed of the motor and increases the torque.

4. The marine gangway support chain and support cable take-up and release device according to claim 3, characterized in that, The gearbox (32) is equipped with an emergency operation handle (34) on its drive shaft. The emergency operation handle (34) is detachable.

5. The marine gangway support chain and support cable take-up and release device according to claim 3, characterized in that, It also includes an electrical control system (4). The servo motor (31) is connected to the electrical control system (4) via a cable. The electrical control system (4) includes an electrical control box (41), a braking resistor box (42), and a position sensor (43). The electrical control box (41) is equipped with a button (411) or a knob (412) and an audible and visual alarm (413). The winch (3) is controlled to rotate forward or backward by the button (411) or the knob (412) on the electrical control box (41). The position sensor (43) is located near both ends of the trolley rail (22).

6. The method for launching and retracting the marine gangway support chain and support cable launch device as described in any one of claims 1-5, characterized in that, The steps are as follows: When the gangway is opened, the winch (3) releases the traction cable (25), and the trolley (23), under the traction of the load-bearing chain cable (5), drives the load-bearing chain cable (5) to slide towards the bow through the guide wheel (24), releasing the load-bearing chain cable (5) and maintaining appropriate tension to prevent the winch (3) from being excessively dragged backward by the load-bearing chain cable (5) and damaged. After the gangway is opened to the position, the load-bearing chain cable (5) is stretched to the load-bearing state, and the load-bearing eye plate (12) and the load-bearing wheel (11) transfer the load borne by the load-bearing chain cable (5) to the hull structure. During the operation of the gangway, the load borne by the load-bearing chain cable (5) will not be transferred to the winch (3), causing damage to the winch (3). When the gangway is closed, the winch (3) retracts the traction cable (25), and the pulley (23), under the traction of the traction cable (25), drives the load-bearing chain (5) to slide towards the stern through the guide wheel (24), retracting the excessively slack load-bearing chain (5) and avoiding interference between the load-bearing chain (5) and the gangway or hull structure. Under the action of the guide wheel (24) at the front end of the pulley (23), the load-bearing chain (5) is stored in the traction bracket (21). The guide wheel (24) at the front end of the pulley (23) acts as a movable pulley, and its travel distance is half the storage length of the load-bearing chain (5), saving the installation space of the device and reducing the occupation of overall resources.

7. The method for retracting and extending the marine gangway support chain and support cable retracting and extending device according to claim 6, characterized in that, The operation control mode of the aforementioned release and take-up method has three implementation methods: A. "Constant Torque" Control Mode: In this mode, the servo motor (31) of the winch (3) maintains a constant output torque and rotates forward. After passing through the gearbox (32), it serves as the driving torque. This torque, together with the load resistance torque generated by the tension of the traction cable (25), acts on the drum (33). When the driving torque is equal to the load resistance torque, the servo motor (31) stalls, and the drum (33) remains stationary. When the driving torque is greater than the load resistance torque, the servo motor (31) drives the drum (33) to rotate forward, retracting the traction cable (25). When the driving torque is less than the load resistance torque, the servo motor (31) is dragged by the drum (33) to rotate backward, releasing the traction cable (25). B. "Retract and Release" Control Mode: This is the normal winch control mode. The servo motor (31) of the winch (3) is used as a normal motor. The operator makes the winch (3) rotate forward or reverse by operating the button (411) or knob (412) on the electrical control box (41) to retract or release the traction cable (25). C. "Manual Emergency" Operation Mode: When the device loses power or the electrical control system fails, the electromagnetic brake of the servo motor (31) is released, and the emergency operation handle (34) is cranked to directly rotate the transmission shaft of the gearbox (32), and the drum (33) is manually driven to wind up and unwind the traction cable (25).

8. The method for retracting and extending the marine gangway support chain and support cable retracting and extending device according to claim 7, characterized in that, The shipboard gangway support chain and support cable take-up and release device can be set independently outside the gangway control system and controlled independently by the electrical control system (4), or it can be controlled in conjunction with the gangway. When controlled independently, the shipboard gangway support chain and support cable retraction device does not have the interlocking function with the gangway. The winch can be operated and controlled independently in the "retraction" working mode, "constant torque" working mode or "manual emergency" operating mode (3). During joint control, the winch (3) automatically switches to the "constant torque" working mode, and the shipboard ramp support chain and support cable take-up and release device are linked with the ramp, which has the interlocking function with the ramp.

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