Marine embarkation gangway ladder with stable structure

Abstract

The utility model discloses a marine embarkation gangway ladder with a stable structure, which comprises a telescopic ladder assembly, the telescopic ladder assembly comprises a main gangway ladder and an auxiliary gangway ladder which are mutually and telescopically connected, the two ends of the main gangway ladder are respectively a fixed end and a connection end, the two ends of the auxiliary gangway ladder are respectively a connection end and a suspension end, and the main gangway ladder and the auxiliary gangway ladder are mutually butted through the respective connection ends; slide ways are arranged on the two axial sides of the main gangway ladder respectively, the cross section of each slide way is similar to an E shape, correspondingly, sliding rails are arranged on the two axial sides of the auxiliary gangway ladder respectively, and the cross section of each sliding rail is similar to a C shape. The C-like sliding rail and the E-like sliding way are mutually engaged and spliced, and the sliding way and the sliding rail are mutually connected in a sliding mode. According to the gangway ladder structure, the stability of the connecting position of the auxiliary gangway ladder and the main gangway ladder is effectively improved through the slideways and the sliding rails which are spliced with each other, the phenomena that the connecting position of the main gangway ladder and the auxiliary gangway ladder is loosened and falls off when the gangway ladder structure shakes due to the influence of stormy waves are avoided, and the safety of the gangway ladder structure is improved.

Description

Technical Field

[0001] This utility model relates to the field of marine operation equipment, and in particular to a structurally stable boarding gangway for marine operations. Background Technology

[0002] The current structure of maritime boarding gangways generally includes a fixed base for the ladder frame, a retractable ladder frame, and clamps for securing the tower. A typical ladder frame includes a main gangway that can be adjusted vertically based on the fixed base, and an auxiliary gangway that can slide and adjust along the main gangway.

[0003] However, traditional ladder frames cannot guarantee a stable connection between the main gangway and the auxiliary gangway. This is because the gangway at sea is subject to the influence of wind and waves during operations. If the connection between the main gangway and the auxiliary gangway is not stable, it may cause the connection between the main gangway and the auxiliary gangway to loosen or fall off, thereby reducing the safety of the gangway structure. Utility Model Content

[0004] To address the technical problems existing in the prior art, the purpose of this utility model is to provide a structurally stable boarding gangway at sea, and to optimize the compensation performance of the gangway, thereby improving the energy efficiency and stability of the overall system.

[0005] The objective of this utility model is achieved through the following technical solution:

[0006] A structurally stable boarding gangway for sea use includes a telescopic ladder frame comprising a main gangway and an auxiliary gangway that are telescopically connected to each other. The two ends of the main gangway are a fixed end and a connecting end, respectively, and the two ends of the auxiliary gangway are a connecting end and a suspended end, respectively. The main gangway and the auxiliary gangway are connected to each other through their respective connecting ends. The main gangway has slide rails on both sides along its axial direction, and the cross-section of the slide rails is similar to the letter E. Correspondingly, the auxiliary gangway has rails on both sides along its axial direction, and the cross-section of the rails is similar to the letter C. The C-shaped rails and the E-shaped slide rails are interlocked and spliced, and the slide rails and rails are slidably connected to each other.

[0007] Specifically, the slide rail includes two first flanges, a partition in the middle, and two slide rail cavities. The slide rail includes two second flanges and a slide rail cavity in the middle. The slide rail cavity corresponds to the partition of the slide rail, and the two second flanges correspond to the two slide rail cavities respectively.

[0008] Furthermore, the two second flanges extend in opposite directions to form baffles, so that after the slide rail and slide track are connected, they form a four-sided enclosed accommodating space with one at the top and one at the bottom, in which a rotor is installed. The rotor is rotatably connected to the slide track through a rotating shaft, and the rotor is slidably connected to the slide rail.

[0009] Specifically, the rotor comprises a horizontally rotating rotor and a vertically rotating rotor.

[0010] Specifically, the partition of the slide is a hollow cylinder, and a telescopic cylinder is arranged in the hollow cylinder, and the end of the piston rod of the telescopic cylinder is hung on the two sides of the axial direction of the suspended end of the auxiliary gangway.

[0011] Further, the multi-angle compensation mechanism comprises a joint assembly and an adjusting assembly, the adjusting assembly comprises an adjusting rod, a shaft sleeve, two adjusting springs and two side springs, the auxiliary gangway is provided with a containing cavity for containing the adjusting assembly at the suspended end, the shaft sleeve is embedded and fixed with the end face of the suspended end, the shaft sleeve sleeves the adjusting rod, the adjusting rod can be movably in and out of the shaft sleeve, the adjusting rod comprises a fixed end and a movable end, the fixed end is fixedly connected with the joint assembly, and the movable end is connected with the two side springs fixed on the auxiliary gangway, and the two adjusting springs are respectively sleeved on the two ends of the adjusting rod and abut against the two ends of the shaft sleeve.

[0012] Specifically, the two side springs are symmetrically arranged horizontally, and the two side springs are arranged perpendicularly to the adjusting rod.

[0013] Further, the joint assembly comprises a hinged rod, a front end plate and a rear end plate, the two ends of the hinged rod are connected with the front end plate and the rear end plate through horizontal hinging and vertical hinging respectively, the front end plate is used for being connected with a hoop, and the rear end plate is connected with the fixed end of the adjusting rod.

[0014] Further, the joint assembly further comprises a first spring group, and the first spring group is symmetrically and coaxially arranged on the outer periphery of the hinged rod and connected with the front end plate and the rear end plate.

[0015] Specifically, the first spring group comprises four springs, and the four springs are arranged around the periphery of the hinged rod.

[0016] Compared with the prior art, the utility model has the following effects:

[0017] 1. The slide and the slide rail are spliced with each other, the stability of the connection position of the auxiliary gangway and the main gangway is effectively improved, the loosening and falling of the connection position of the main gangway and the auxiliary gangway when the gangway structure shakes under the influence of wind and waves is avoided, and the safety of the gangway structure is improved.

[0018] 2. The multi-angle compensation mechanism can realize longitudinal displacement and swinging to a certain extent, can passively compensate the bumping caused by sea wave fluctuation, can ensure the stability of the offshore boarding gangway, can be quickly positioned, has high safety and reliability, greatly protects the safety of workers and equipment, and has high practical value. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 Structure diagram of the offshore embarkation gangway of the present embodiment.

[0020] Figure 2 Structure diagram of the offshore embarkation gangway of the present embodiment after the removal of the upper plate of the extension ladder frame.

[0021] Figure 3 Structure diagram of the extension ladder frame, the main gangway, the slide and the slide rail.

[0022] Figure 4 Structure diagram of the connection between the extension ladder frame, the multi-angle compensation mechanism and the clamp.

[0023] Figure 5 Structure diagram of the disassembly of the multi-angle compensation mechanism.

[0024] Figure 6 Structure diagram of the present embodiment, the pitch and the XYZ axial indication.

[0025] In the figure:

[0026] 10 - control platform; 11 - rotary base; 13 - embarkation ladder; 15 - pitch compensation mechanism;

[0027] 20 - extension ladder frame; 21 - main gangway; 214 - fixed end; 216 - connection end of the main gangway; 218 - slide; 2181 - first flange; 2182 - partition; 2183 - slide cavity; 2184 - blocking strip; 23 - auxiliary gangway; 236 - connection end of the auxiliary gangway; 234 - suspended end; 238 - slide rail; 2385 - second flange; 2386 - slide rail cavity; 2488 - rotor; 25 - driving device; 250 - piston rod;

[0028] 30 - multi-angle compensation mechanism; 371 - hinged rod; 372 - front end plate; 373 - rear end plate; 374 - first spring group; 395 - adjusting rod; 396 - shaft sleeve; 397 - adjusting spring; 398 - side spring;

[0029] 40 - clamp; 42 - clamping seat; 44 - clamping jaw; 46 - driver. DETAILED DESCRIPTION

[0030] For the convenience of understanding the utility model, the following will be combined with the drawings and examples, and the technical scheme and advantages of the utility model will be further described in detail. The mechanisms or methods not described in the utility model can be referred to the prior art. The specific structure and characteristics of the utility model will be described in the following example, which should not constitute any limitation on the utility model. At the same time, any one of the technical features mentioned below (including implied or disclosed) and any one of the technical features directly shown or implied in the drawings can be arbitrarily combined or deleted between these technical features, thereby forming more other embodiments that can not be directly or indirectly mentioned in the utility model. The preferred embodiments of the utility model are shown in the drawings. However, the utility model can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the utility model more comprehensive and thorough.

[0031] As shown in Figures 1-6 The offshore boarding gangway provided by the embodiment can be installed on the two sides of a ship for the boarding and disembarking of passengers. In addition, one end of the gangway can be installed on the deck of the ship, and the other end of the gangway can be clamped on a wind power tower drum, so that maintenance personnel can reach the tower drum through the gangway to perform maintenance work.

[0032] The offshore boarding gangway of the embodiment comprises a control platform 10, an extendable ladder stand 20, a multi-angle compensation mechanism 30 and a clamp 40. The control platform 10 is generally placed on the deck of the ship. The control platform 10 is movably connected with the main gangway 21 of the extendable ladder stand 20, so that the extendable ladder stand 20 can make horizontal rotation and pitching movement based on the control platform 10. The auxiliary gangway 23 of the extendable ladder stand 20 is connected with the clamp 40 through the multi-angle compensation mechanism 30, and the clamp 40 can clamp the wind power tower drum.

[0033] Specifically, the control platform 10 comprises a rotary base 11, a boarding ladder 13, a rotary compensation mechanism and a pitching compensation mechanism 15. The rotary base 11 is generally fixedly placed on the deck of the ship. The rotary compensation mechanism is arranged in the rotary base 11, and the boarding ladder 13 is arranged on the rotary base 11. The boarding ladder 13 makes horizontal rotation through the rotary compensation mechanism.

[0034] The telescopic ladder frame 20 comprises a main gangway 21 and a sub-gangway 23 connected with each other, the two ends of the main gangway 21 are a fixed end 214 and a connecting end 216 respectively, and the two ends of the sub-gangway 23 are a connecting end 236 and a free end 234 respectively. The fixed end 214 of the main gangway 21 of the telescopic ladder frame 20 is hinged to the boarding ladder 13, so that the telescopic ladder frame 20 can make pitching movement with the boarding ladder 13 as the axis. The main gangway 21 and the sub-gangway 23 are connected with each other through the respective connecting ends 216 / 236, so that the sub-gangway 23 can be coaxially retracted or extended outwardly with respect to the main gangway 21 to realize telescopic function. The free end 234 of the sub-gangway 23 is connected to the clamp 40 through the multi-angle compensation mechanism 30. The staff can walk along the main gangway 21 and the sub-gangway 23 of the telescopic ladder frame 20 to the fan tower.

[0035] On the basis that the fixed end 214 of the main gangway 21 of the telescopic ladder frame 20 is hinged to the boarding ladder 13, the pitching compensation mechanism 15 of the control platform 10 is connected to the main gangway 21 of the telescopic ladder frame 20 and the boarding ladder 13 respectively to realize pitching movement compensation. In the embodiment, the pitching compensation mechanism 15 preferably comprises two hydraulic cylinders. The body of the hydraulic cylinder is arranged on the boarding ladder 13, and the piston rod of the hydraulic cylinder is connected to the main gangway 21 of the telescopic ladder frame 20 in a supporting manner on the two sides of the telescopic ladder frame 20 in the axial direction, and the lifting or lowering of the telescopic ladder frame 20 can be adjusted by controlling the hydraulic cylinder.

[0036] The connecting mode of the main gangway 21 and the sub-gangway 23 of the telescopic ladder frame 20 is that the two sides of the main gangway 21 in the axial direction are respectively provided with slideways 218, and correspondingly, the two sides of the sub-gangway 23 in the axial direction are respectively provided with slide rails 238, and the slideways 218 and the slide rails 238 are connected with each other in a sliding manner.

[0037] Specifically, the cross section of the slideway 218 of the main gangway 21 is similar to the letter E type, and the inner recessed parts of the two sides of the slideway 218 are arranged oppositely in an inner embracing manner. The slideway 218 in the E type comprises two first flanges 2181 arranged above and below, a partition part 2182 arranged in the middle, and two slideway cavities 2183 formed by the two first flanges 2181 and the partition part 2182. The partition part 2182 of the slideway 218 is a hollow cylindrical shape, and the driving device 25 is arranged in the partition part 2182, and the transmission part of the driving device 25 extends out of the partition part 2182 and is connected to the sub-gangway 23. In the embodiment, the driving device 25 is preferably a telescopic cylinder, and the end of the piston rod 250 of the telescopic cylinder is hung on the side of the free end 234 on the two sides of the sub-gangway 23 in the axial direction. By controlling the two telescopic cylinders arranged symmetrically, synchronous transmission is realized to control the telescoping of the sub-gangway 23, so that the effect of balanced braking is achieved, and the telescoping jamming under the influence of the harsh sea environment is avoided.

[0038] The cross section of the slide rail 238 of the auxiliary gangway 23 is similar to a letter C, and the inner recessed portions of the slide rails 238 on both sides are oppositely arranged. The slide rail 238 in the shape of a letter C includes two second flanges 2385 arranged above and below and a slide rail cavity 2386 formed in the middle. The slide rail cavity 2386 corresponds to the partition portion 2182 of the slide channel 218, and the two second flanges 2385 correspond to the two slide channel cavities 2183, respectively. By engaging the slide rail 238 in the shape of a letter C with the slide channel 218 in the shape of a letter E, the main gangway 21 and the auxiliary gangway 23 of the telescopic ladder stand 20 are connected more firmly and are not easily affected by sea waves.

[0039] In addition, the two second flanges of the slide rail 238 extend oppositely to form a baffle 2484, so that the slide rail 238 and the slide channel 218 form an accommodation space above and below after being connected, and the rotor 2488 is placed in the accommodation space. The rotor 2488 is rotationally connected to the slide channel 218 through a shaft, the rotor 2488 is slidingly connected to the slide rail 238, the rotor 2488 reduces the friction during the sliding of the slide rail 238 and the slide channel 218, and the slide rail 238 and the slide channel 218 slide more smoothly and stably. Preferably, the rotor 2488 includes a horizontal rotor and a vertical rotor, which ensures that the sliding in the horizontal direction and the vertical direction both achieve the effect of reducing friction.

[0040] Further, the connection relationship between the other parts of the slide channel and the slide rail, the baffle of the slide channel and the rotor of the slide rail is exchanged. Specifically, the two first flanges 2181 of the slide channel 218 extend oppositely to form a baffle, and the slide rail 238 and the slide channel 218 form an accommodation space above and below after being connected, and a rotor is arranged in the accommodation space. The rotor is movably connected to the slide rail 238 through a shaft, and the rotor 2488 is slidingly connected to the slide channel 218.

[0041] The multi-angle compensation mechanism 30 includes a joint assembly and an adjusting assembly. One end of the joint assembly is connected with the hoop 40, the other end of the joint assembly is connected with one end of the adjusting assembly, and the other end of the adjusting assembly is connected with the overhanging end 234 of the auxiliary gangway 23 of the telescopic ladder stand 20.

[0042] Specifically, the joint assembly comprises a hinged rod 371, a front end plate 372, a rear end plate 373 and a first spring set 374. One end of the hinged rod 371 is vertically hinged to the front end plate 372, so that the hinged rod 371 can make pitching movement around the connection; the other end of the hinged rod 371 is horizontally hinged to the rear end plate 373, so that the hinged rod 371 can make horizontal rotation around the connection. The first spring set 374 is four springs, which are respectively arranged around the periphery of the hinged rod 371 in up-down and left-right directions, and the two ends of the first spring set 374 are respectively connected to the front end plate 372 and the rear end plate 373, so as to elastically adjust the rotation of the hinged rod 371. That is, when the hinged rod 371 makes pitching movement around the connection with the front end plate 372, the first spring set 374 is divided into upper and lower parts, the upper two springs and the lower two springs are not subjected to the same force, and the first spring set 374 elastically compensates the pitching movement of the joint assembly; when the hinged rod 371 makes horizontal rotation around the connection with the rear end plate 373, the first spring set 374 is divided into left and right parts, the left two springs and the right two springs are not subjected to the same force, and the first spring set 374 elastically compensates the horizontal rotation of the joint assembly.

[0043] In the preferred embodiment of the present application, the front end plate 372 is integrally formed with the clamping seat 42 of the hoop 40. In other embodiments, the front end plate 372 can be fixedly connected to the clamping seat 42 of the hoop 40, or the hinged rod 371 is directly connected to the clamping seat 42 of the hoop 40, and only the first spring set 374 is connected to the front end plate 372. In other embodiments, the connection modes of the hinged rod 371 and the front end plate 372 and the rear end plate 373 can be interchanged. The principle is still within the concept of the present application.

[0044] The adjusting assembly comprises an adjusting rod 395, a shaft sleeve 396, two adjusting springs 397 and two side springs 398. The adjusting rod 395 is a light pole, and its two ends are fixed end and movable end respectively. The fixed end is fixedly connected to the rear end plate 373, so that the front end plate 372, the hinged rod 371, the rear end plate 373 and the adjusting rod 395 are sequentially connected in series. The shaft sleeve 396 is sleeved with the adjusting rod 395, so that the adjusting rod 395 can be moved in and out of the shaft sleeve 396. The auxiliary gangway 23 of the telescopic ladder frame 20 is provided with a containing cavity for containing the adjusting assembly at the overhanging end 234. The shaft sleeve 396 is embedded with the end surface of the overhanging end 234 and fixed, and the movable end of the adjusting rod 395 extends to the containing cavity of the auxiliary gangway 23. The containing cavity reserves enough space for the movable end of the adjusting rod 395 to move. The two adjusting springs 397 are respectively sleeved on the two ends of the adjusting rod 395 and elastically abut against the two ends of the shaft sleeve 396. The two side springs 398 are respectively arranged on the corresponding two sides of the movable end of the adjusting rod 395, one end of the side spring 398 is connected to the movable end of the adjusting rod 395, and the other end of the side spring 398 is fixedly connected to the auxiliary gangway 23 of the telescopic ladder frame 20, so as to ensure that the side spring 398 is horizontally stretched and arranged perpendicular to the adjusting rod 395. When the telescopic ladder frame 20 and the hoop 40 are displaced forward and backward (close or away), the joint assembly is extruded or stretched by the force in the axial direction of the adjusting rod 395, the joint assembly transmits the force through the rear end plate 373, extrudes or stretches the adjusting rod 395, the adjusting rod 395 moves axially and extrudes or stretches the two adjusting springs 397 and the two side springs 398 on the front and back sides, so as to realize the motion compensation of the forward and backward displacement. When the telescopic ladder frame 20 and the hoop 40 are relatively twisted (twisted in the vertical direction), the joint assembly is twisted by the force around the adjusting rod 395, the joint assembly transmits the force through the rear end plate 373, the adjusting rod 395 rotates and twists the two side springs 398 on the two sides, so as to realize the motion compensation of the twist.

[0045] The hoop 40 is a horizontal opening type, which comprises a clamping seat 42, two clamping jaws 44 and a driver 46. The clamping seat 42 is integrally formed with the front end plate 372 of the joint assembly. The two clamping jaws 44 are respectively hinged on the two sides of the clamping seat 42, and the driver 46 is installed on the clamping seat 42. The transmission components of the driver 46 are respectively connected with the two clamping jaws 44. The two clamping jaws 44 are driven by the driver 46 to move towards each other and tightly hold the workpiece, which refers to the wind power tower drum.

[0046] It should be noted that the ship body will produce rotational oscillation movement due to static pressure imbalance or circular motion of water in the sea waves and other factors. The offshore embarkation gangway carried on the ship body will also be affected. Using the Cartesian rectangular coordinate system to describe, the bow-stern (forward and backward) direction of the ship is called longitudinal, represented by X. The left-right side (left and right) direction is called transverse, represented by Y. The upper deck-bottom of the ship (up and down) direction is called vertical, represented by Z. The sway (surge, roll) in the forward and backward direction is called longitudinal sway, the sway (surge, roll) in the left and right direction is called transverse sway, and the sway (surge, roll) in the up and down direction is called vertical sway. The yaw in the forward and backward direction is called longitudinal yaw, the yaw in the left and right direction is called transverse yaw, and the yaw of the bow in the left and right direction is called bow yaw. The sway (roll) is translation, such as longitudinal sway moving along the X axis, transverse sway moving along the Y axis, and vertical sway moving along the Z axis. The moving distance of each position of the ship is the same. The yaw (roll) is rotation around a virtual coordinate axis. The longitudinal yaw and the transverse yaw are rotation around the Y axis and the X axis respectively, and the bow yaw is rotation around the Z axis. The yaw angle of each position of the ship is the same, but the displacement distance is different. The ship is in water, and the actual roll and yaw occur simultaneously, but they are artificially divided into different combinations. The so-called six degrees of freedom is that in the Cartesian rectangular coordinate system, the six motion forms of moving along three axes and rotating around three axes are called six degrees of freedom. The offshore embarkation gangway of the embodiment can be conveniently understood in the unstable environment condition encountered in offshore operation by replacing the ship body in the above example.

[0047] In the use process of the offshore embarkation gangway of the embodiment, the stability of the connection between the auxiliary gangway and the main gangway is effectively improved through the mutually spliced slide and slide rail, so that the loosening and falling of the connection between the main gangway and the auxiliary gangway when the gangway structure is affected by wind and waves is avoided, and the safety of the gangway structure is improved. The multi-angle compensation mechanism cooperates with the telescopic ladder frame to realize multi-angle and mechanical passive compensation of the bump caused by sea wave fluctuation, so as to ensure the stability of the offshore embarkation gangway. The structure is compact, does not need manual intervention, realizes real-time feedback compensation, and shows strong innovative idea.

[0048] The above-mentioned embodiments are only preferred embodiments of the present application, and cannot be used to limit the scope of protection of the present application. For those skilled in the art, it can be understood that the embodiments can be changed, modified, replaced and modified in various ways without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A structurally stable offshore embarkation gangway, characterized in that The utility model provides a telescopic ladder frame, which comprises a main gangway and a sub-gangway connected with each other in a telescopic manner, two ends of the main gangway are a fixed end and a connecting end respectively, two ends of the sub-gangway are a connecting end and a hanging end respectively, and the main gangway and the sub-gangway are connected with each other through the respective connecting ends; two sides of the main gangway in the axial direction are respectively provided with a slide way, the cross section of the slide way is similar to the letter E, and correspondingly, two sides of the sub-gangway in the axial direction are respectively provided with a slide rail, the cross section of the slide rail is similar to the letter C; the slide rail and the slide way are connected with each other in a sliding mode through the engagement of the slide rail with the letter C and the slide way with the letter E.

2. A structurally stable marine boarding stair as claimed in claim 1, characterized in that The slide way comprises two first flanges, a partition in the middle and two slide way cavities, the slide rail comprises two second flanges and a slide rail cavity in the middle, the slide rail cavity is matched with the partition of the slide way, and the two second flanges are matched with the two slide way cavities respectively.

3. A structurally stable marine boarding stair as claimed in claim 2, characterised in that, The two second flanges extend in opposite directions to form a baffle, so that the slide rail and the slide way form a four-square containing space after being connected, a rotor is arranged in the containing space, the rotor is connected with the slide way in a rotating mode through a rotating shaft, and the rotor is connected with the slide rail in a sliding mode.

4. A structurally stable marine boarding stair as claimed in claim 3, wherein, The rotor comprises a horizontal rotor and a vertical rotor.

5. The structurally stable marine boarding stair according to claim 2, wherein, The partition of the slide way is a hollow cylinder, a telescopic cylinder is arranged in the partition, and the piston rod of the telescopic cylinder is hung on both sides of the hanging end of the sub-gangway in the axial direction.

6. The structurally stable marine boarding stair of claim 1, wherein, The utility model also provides a multi-angle compensation mechanism, which comprises a joint assembly and an adjusting assembly, the adjusting assembly comprises an adjusting rod, a shaft sleeve, two adjusting springs and two side springs, the sub-gangway is provided with a cavity for accommodating the adjusting assembly at the hanging end, the shaft sleeve is embedded and fixed with the end face of the hanging end, the shaft sleeve is sleeved with the adjusting rod, the adjusting rod can be moved in and out of the shaft sleeve, the adjusting rod comprises a fixed end and a movable end, the fixed end is fixedly connected with the joint assembly, the movable end is connected with the two side springs fixed on the sub-gangway, and the two adjusting springs are sleeved with both ends of the adjusting rod and abut against both ends of the shaft sleeve.

7. A structurally stable marine boarding stair according to claim 6, wherein The two side springs are symmetrically arranged horizontally, and the two side springs are arranged perpendicularly to the adjusting rod.

8. A structurally stable marine boarding stair as defined in claim 6, wherein, The joint assembly comprises a hinged rod, a front end plate and a rear end plate, both ends of the hinged rod are connected with the front end plate and the rear end plate through horizontal hinging and vertical hinging respectively, the front end plate is used for being connected with a hoop, and the rear end plate is connected with the fixed end of the adjusting rod.

9. A structurally stable marine boarding stair according to claim 8, wherein The joint assembly further comprises a first spring group, the first spring group is symmetrically and coaxially arranged on the outer periphery of the hinged rod and connected with the front end plate and the rear end plate.

10. A structurally stable marine boarding stair as claimed in claim 9, characterised in that, The first spring group comprises four springs, which are arranged around the periphery of the hinged rod in an up-down and left-right manner.

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