Adjustable boarding ladder

Abstract

The invention provides an adjustable boarding ladder, and relates to the technical field of marine equipment, the adjustable boarding ladder comprises a frame body structure and a support column structure, the support column structure comprises a support cylinder and a movable column, and a rotation control device is arranged at the joint of the support cylinder and the movable column; the frame body structure comprises a first platform and a second platform, a movable ladder assembly is arranged on one side of the first platform, and a lifting piece used for controlling the movable ladder assembly to rise and fall is arranged at the upper end of a movable column; a fixed ladder assembly is arranged on one side of the second platform, a climbing channel is arranged between the first platform and the second platform, an escape channel is arranged below the second platform, and a pawl limiting device is arranged on the outer side of the supporting cylinder, arranged between the first platform and the second platform and used for limiting rotation of the movable column so that escape can be conducted safely. The boarding ladder is of a double-layer structure, the first platform is communicated with the second platform through the climbing channel, and when congestion occurs on the second platform, people can be divided through the escape channel, so that the occurrence of trampling conditions can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of marine equipment, and in particular to an adjustable boarding ladder. Background Art

[0002] Ships, as one of the important means of transportation for today's economic development, have advantages that other means of transportation cannot match. In recent years, with the acceleration of the process of world economic integration, the maritime transportation industry has become busier, the world shipbuilding market has also been extremely hot, and the demand for ships has reached an unprecedented level. The boarding ladder is a passage facility between the ship and the outside world. The boarding ladder refers to a movable ladder installed on both sides of the ship for passengers to get on and off the ship. It is made of wood or metal. It consists of upper and lower platforms, ladder frames, ladder steps, railings and ladder devices. It is hoisted when the ship is sailing, folded and stored on the deck, and lowered and hung on the side when in use.

[0003] For example, the Chinese patent with application number CN201711326709.0 discloses a dock boarding ladder that can be adjusted in all directions automatically, including a landing platform, a boarding inclined ladder and a boarding platform, a landing support platform is provided on the top of the landing platform, roller bearing tracks are provided on both sides of the landing support platform, a movable platform is provided in the roller bearing track, roller bearings are provided on both sides of the movable platform, so that the movable platform can only slide back and forth along the roller bearing track on the landing support platform and does not separate from the landing support platform, one end of the boarding support platform is suspended outside the ship's side, and is hinged to the upper part of the 7-shaped rotating shaft, the 7-shaped rotating shaft can be rotatable and does not separate from the boarding support platform, and the other end of the boarding support platform is provided with support legs and ladder steps, and a weight is provided to press the boarding support platform to stabilize the entire boarding platform. The present invention can automatically eliminate the shaking caused by the irregular swaying of the ship, so that the boarding ladder always remains relatively stable, increases the safety of personnel boarding the ladder, and prolongs the service life of the boarding ladder. However, since the supporting platform of this type of boarding ladder is set in a relatively fixed position, the angle setting is not flexible enough when facing ships at multiple angles. For this reason, some ladder frames adopt a rotating design. The disadvantage of the rotating ladder frame is that due to the adjustment in one more direction, the ladder frame will rotate and swing when bumps occur. If congestion occurs on the platform, the single-channel design makes it difficult to divert personnel, which in turn leads to trampling, and safety needs to be improved. Summary of the invention

[0004] In view of the above problems, the present invention proposes an adjustable boarding ladder. The boarding ladder adopts a double-layer structure. The second platform is the first layer, and the first platform is the second layer. The fixed ladder frame is fixed to the second platform. One can board the second platform through the fixed ladder frame and board the first platform through the movable ladder frame. The first platform and the second platform are connected by a climbing passage. The movable ladder frame is hinged to the first platform. The lifting member controls the lifting of the movable ladder frame to adjust the set height of the movable ladder frame. By controlling the rotation of the movable column through the rotation control device, the movable ladder frame can be smoothly placed on the ship's side in different directions, with high flexibility.

[0005] To achieve the object of the present invention, the present invention is realized through the following technical solutions: An adjustable boarding ladder includes a frame structure and a support column structure. The support column structure includes a support cylinder and a movable column. The movable column is rotatably connected to the upper end of the support cylinder. A rotation control device is provided at the connection between the support cylinder and the movable column. The frame structure includes a first platform and a second platform. The first platform is fixedly connected to the outside of the movable column, and the second platform is fixedly connected to the outside of the support cylinder. The first platform is placed above the second platform. One side of the first platform is provided with a movable ladder frame. The movable ladder frame is hinged to the first platform. A lifting member for controlling the lifting and lowering of the movable ladder frame is provided at the upper end of the movable column. One side of the second platform is provided with a fixed ladder frame. The fixed ladder frame is fixedly connected to the second platform. A climbing passage is provided between the first platform and the second platform. An escape passage is provided below the second platform. A pawl limiting device is provided on the outside of the support cylinder. The pawl limiting device is placed between the first platform and the second platform to limit the rotation of the movable column to ensure safe escape.

[0006] Further improvement lies in that: The rotation control device includes a positioning column, a first gear, a second gear, and a motor. The positioning column is fixedly connected to the lower end of the movable column. The first gear is sleeved on the outside of the positioning column, and the positioning column is fixedly connected to the first gear. The motor is fixedly connected to the inside of the support cylinder, and the output end of the motor is fixedly connected to the second gear. The second gear meshes with the first gear.

[0007] Further improvement lies in that: The lifting member includes a support plate and hydraulic telescopic rods provided on the left and right sides of the movable ladder frame. The support plate is fixedly connected to the upper end of the movable column. The installation end of the hydraulic telescopic rod is hinged to the support plate, and the output end of the hydraulic telescopic rod is hinged to the upper end of the movable ladder frame.

[0008] Further improvement lies in that: The pawl limiting device includes a ratchet wheel, an operation window, a rotating shaft, a pawl, and a worm and worm gear mechanism. The ratchet wheel is sleeved on the outside of the positioning column, and the positioning column is fixedly connected to the ratchet wheel. The operation window is opened on the outside of the support cylinder. The rotating shaft is rotatably arranged inside the operation window. A pawl is fixedly connected to the outside of the rotating shaft. The pawl cooperates with the pawl provided on the outside of the ratchet wheel. A worm and worm gear mechanism for controlling the rotation of the rotating shaft is provided inside the operation window.

[0009] Further improvements are as follows: The climbing passage includes a first window and a movable ladder. The first window is opened at the lower end of the first platform. The movable ladder is fixedly connected to the lower end of the first platform. A first support and a first diagonal brace are respectively arranged on the left and right sides of the movable ladder. The first support and the first diagonal brace are fixedly connected to the movable ladder and are also fixedly connected to the lower end of the first platform.

[0010] Further improvements are as follows: A first hinged window is arranged outside the first window. One end of the first hinged window is hinged to the upper end of the first platform through a pivot. A first buckle is arranged at the other end of the first hinged window, and the first buckle is buckled with a slot opened at the upper end of the first platform.

[0011] Further improvements are as follows: The escape passage includes a second window and a fixed ladder fixed on the ground. The second window is opened at the lower end of the movable ladder frame. The upper end of the fixed ladder is fixedly connected to the lower end of the movable ladder frame. A second support and a second diagonal brace are respectively arranged on the left and right sides of the fixed ladder. The second support and the second diagonal brace are fixedly connected to the fixed ladder and are also fixedly connected to the lower end of the second platform.

[0012] Further improvements are as follows: A second hinged window (27) is arranged outside the second window. One end of the second hinged window (27) is hinged to the upper end of the second platform through a pivot. A second buckle is arranged at the other end of the second hinged window (27), and the second buckle is buckled with a slot opened at the upper end of the second platform.

[0013] Further improvements are as follows: A first fence for preventing people from falling is arranged along the upper edge of the first platform and the movable ladder frame. Two groups of first fences are fixedly connected to the first platform and the movable ladder frame. Multiple groups of universal wheels are arranged at the lower end of the movable ladder frame.

[0014] Further improvements are as follows: A second fence for preventing people from falling is arranged along the upper edge of the second platform and the fixed ladder frame. The second fence is fixedly connected to the second platform and the fixed ladder frame.

[0015] The boarding ladder of the present invention adopts a double-layer structure. The second platform is the first layer, and the first platform is the second layer. The fixed ladder frame is fixedly connected to the second platform. One climbs onto the second platform through the fixed ladder frame and onto the first platform through the movable ladder frame. The first platform and the second platform are connected through a climbing passage. The movable ladder frame is hinged to the first platform. The lifting member is used to control the lifting of the movable ladder frame to adjust the set height of the movable ladder frame. The rotation control device is used to control the rotation of the movable column, so that the movable ladder frame can be smoothly placed on the ship's side in different directions with high flexibility. In addition to the fixed ladder frame arranged on the second platform, an escape passage is also arranged below the second platform. When there is congestion on the second platform, personnel can be diverted through the escape passage, which can effectively reduce the occurrence of trampling. The rotation of the movable column is restricted by the pawl limiting device to provide safety guarantee for escape. Description of the Drawings

[0016] Figure 1 It is the structural diagram of the movable ladder in the present invention; Figure 2 It is the structural diagram of the fixed ladder in the present invention; Figure 3 It is the structural diagram of the inner side of the support cylinder in the present invention; Figure 4 It is the structural diagram of the first platform in the present invention; Figure 5 It is the structural diagram of the movable ladder in the present invention; Figure 6 It is the structural diagram of the second platform in the present invention; Figure 7 It is the present invention Figure 3 The enlarged structural diagram at position A in.

[0017] Wherein: 1. Support cylinder; 2. Movable column; 3. First platform; 4. Second platform; 5. Movable ladder; 6. Universal wheel; 7. Fixed ladder; 8. Support plate; 9. Hydraulic telescopic rod; 10. First fence; 11. Second fence; 12. First window; 13. Movable ladder; 14. Second window; 15. Fixed ladder; 16. Operation window; 17. Positioning column; 18. First gear; 19. Second gear; 20. Motor; 21. Ratchet; 22. Pawl; 23. First hinged window; 24. First buckle; 25. First bracket; 26. First diagonal brace; 27. Second hinged window; 28. Second buckle; 29. Second bracket; 30. Second diagonal brace; 31. Rotating shaft; 32. Claw; 33. Worm and worm gear mechanism. Specific embodiments

[0018] In order to deepen the understanding of the present invention, the following will further describe the present invention in combination with embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation to the protection scope of the present invention.

[0019] According to Figures 1 - 7 As shown, this embodiment proposes an adjustable boarding ladder, including a frame structure and a pillar structure. The pillar structure includes a support cylinder 1 and a movable column 2. The movable column 2 is rotatably connected to the upper end of the support cylinder 1, and a rotation control device is provided at the connection between the support cylinder 1 and the movable column 2; The frame structure includes a first platform 3 and a second platform 4. The first platform 3 is fixedly connected to the outside of the movable column 2, the second platform 4 is fixedly connected to the outside of the support cylinder 1, and the first platform 3 is placed above the second platform 4; One side of the first platform 3 is provided with a movable ladder 5. The movable ladder 5 is hinged to the first platform 3, and a lifting member for controlling the lifting and lowering of the movable ladder 5 is provided at the upper end of the movable column 2; One side of the second platform 4 is provided with a fixed ladder 7, which is fixedly connected to the second platform 4. A climbing passage is provided between the first platform 3 and the second platform 4, and an escape passage is provided below the second platform 4. A pawl limiting device is provided outside the support cylinder 1, and the pawl limiting device is arranged between the first platform 3 and the second platform 4 to limit the rotation of the movable column 2 to ensure safe escape.

[0020] The boarding ladder adopts a double-layer structure. The second platform 4 is the first layer, and the first platform 3 is the second layer. The fixed ladder 7 is fixed to the second platform 4. One can board the second platform 4 through the fixed ladder 7 and board the first platform 3 through the movable ladder 5. The first platform 3 and the second platform 4 are connected through a climbing passage. The movable ladder 5 is hinged to the first platform 3. The lifting member is used to control the lifting of the movable ladder 5, adjust the set height of the movable ladder 5, and the rotation control device is used to control the rotation of the movable column 2, so that the movable ladder 5 can be smoothly placed on the ship's side in different directions, with high flexibility.

[0021] The first platform 3 is connected to the second platform 4 through a climbing passage. In addition to the fixed ladder 7, an escape passage is also provided below the second platform 4. When there is congestion on the second platform 4, personnel can be diverted through the escape passage, which can effectively reduce the occurrence of trampling. The rotation of the movable column 2 is restricted by the pawl limiting device to provide safety guarantee for escape.

[0022] Regarding the rotation control device: The rotation control device includes a positioning column 17, a first gear 18, a second gear 19 and a motor 20. The positioning column 17 is fixedly connected to the lower end of the movable column 2. The first gear 18 is sleeved outside the positioning column 17, and the positioning column 17 is fixedly connected to the first gear 18. The motor 20 is fixedly connected to the inner side of the support cylinder 1, and the output end of the motor 20 is fixedly connected to the second gear 19. The second gear 19 meshes with the first gear 18. By controlling the rotation of the second gear 19 by the motor 20, the second gear 19 meshes with the first gear 18 during rotation, driving the first gear 18 to rotate. Since the first gear 18 is fixed to the positioning column 17, when the first gear 18 rotates, the positioning column 17 and the movable column 2 will also rotate accordingly to adjust the orientation of the movable ladder 5.

[0023] The lifting member is used to control the lifting and lowering height of the movable ladder 5. Specifically, the lifting member includes a support plate 8 and hydraulic expansion rods 9 arranged on the left and right sides of the movable ladder 5. The support plate 8 is fixedly connected to the upper end of the movable column 2. The mounting end of the hydraulic expansion rod 9 is hinged to the support plate 8, and the output end of the hydraulic expansion rod 9 is hinged to the upper end of the movable ladder 5. The movable ladder 5 is hinged to the first platform 3. The movable ladder 5 and the support plate 8 are connected by at least two hydraulic expansion rods 9. The lifting and lowering of the movable ladder 5 are controlled by the hydraulic expansion rods 9.

[0024] Regarding the pawl limiting device: The pawl limiting device includes a ratchet wheel 21, an operation window 16, a rotating shaft 31, a pawl 32, and a worm and worm gear mechanism 33. The ratchet wheel 21 is sleeved outside the positioning column 17, and the positioning column 17 is fixedly connected to the ratchet wheel 21. The operation window 16 is opened on the outside of the support cylinder 1. The rotating shaft 31 is rotatably arranged inside the operation window 16. A pawl 32 is fixedly connected to the outside of the rotating shaft 31. The pawl 32 cooperates with a pawl 22 arranged outside the ratchet wheel 21. A worm and worm gear mechanism 33 for controlling the rotation of the rotating shaft 31 is arranged inside the operation window 16. When diverting, an operator controls the rotation of the rotating shaft 31 through the worm and worm gear mechanism 33. During the rotation of the rotating shaft 31, the pawl 32 is driven to rotate, and the pawl 32 is rotated from the outside of the support cylinder 1 to the inside of the support cylinder 1. When the positioning column 17 rotates due to inertia, the pawl 22 on the ratchet wheel 21 will collide with the pawl 32, and the pawl 32 will lock the rotating shaft 31 to limit the rotation of the movable column 2, ensuring the safety of personnel diversion.

[0025] The worm and worm gear mechanism 33 includes a worm wheel, a worm, and a hand-twisting head. The worm wheel is fixed to the outside of the rotating shaft 31. The worm is rotatably arranged inside the operation window 16. The rotation of the worm is controlled by the hand-twisting head. The worm meshes with the worm wheel to rotate the rotating shaft 31, completing the rotation control of the pawl 32. The worm and worm gear mechanism 33 has self-locking property, which can ensure that the pawl 32 will not rotate back after being impacted. The worm and worm gear mechanism 33 is a conventional technology and will not be elaborated here.

[0026] It is worth elaborating that the climbing passage includes a first window 12 and a movable ladder 13. The first window 12 is opened at the lower end of the first platform 3. The movable ladder 13 is fixedly connected to the lower end of the first platform 3. First brackets 25 and first diagonal braces 26 are respectively arranged on the left and right sides of the movable ladder 13. The first brackets 25 and the first diagonal braces 26 are fixedly connected to the movable ladder 13, and the first brackets 25 and the first diagonal braces 26 are fixedly connected to the lower end of the first platform 3 to improve the structural strength of the movable ladder 13 and provide safety guarantee for personnel to pass through the movable ladder 13. The movable ladder 13 is fixed to the first platform 3. When the movable column 2 drives the first platform 3 to rotate, the movable ladder 13 also rotates accordingly, and the movable ladder 13 will not conflict with the structural members between the first platform 3 and the second platform 4 during rotation.

[0027] To prevent the personnel passing through the first platform 3 from accidentally falling out of the first window 12, a first hinged window 23 is provided outside the first window 12. One end of the first hinged window 23 is hinged to the upper end of the first platform 3 through a pivot. A first buckle 24 is provided at the other end of the first hinged window 23, and the first buckle 24 is buckled with a card slot opened at the upper end of the first platform 3. Usually, the movable ladder 13 is in a closed state. When it is necessary to go to the next floor through the movable ladder 13, the first hinged window 23 is pulled upward to open the first hinged window 23. When it is necessary to go to the upper floor through the movable ladder 13, the first hinged window 23 is pushed upward to open it.

[0028] It is worth elaborating that the escape passage includes a second window 14 and a fixed ladder 15 fixed to the ground. The second window 14 is opened at the lower end of the movable ladder frame 5. The upper end of the fixed ladder 15 is fixedly connected to the lower end of the movable ladder frame 5. Second brackets 29 and second diagonal braces 30 are respectively provided on the left and right sides of the fixed ladder 15. The second brackets 29 and the second diagonal braces 30 are fixedly connected to the fixed ladder 15, and the second brackets 29 and the second diagonal braces 30 are fixedly connected to the lower end of the second platform 4; to improve the structural strength of the fixed ladder 15 and provide safety guarantee for personnel to pass through the fixed ladder 15.

[0029] To prevent the personnel passing through the second platform 4 from accidentally falling out of the second window 14, a second hinged window 27 is provided outside the second window 14. One end of the second hinged window 27 is hinged to the upper end of the second platform 4 through a pivot. A second buckle 28 is provided at the other end of the second hinged window 27, and the second buckle 28 is buckled with a card slot opened at the upper end of the second platform 4; the setting method of the second hinged window 27 is the same as that of the first hinged window 23, and will not be elaborated here.

[0030] Furthermore, a first fence 10 for preventing personnel from falling is provided along the upper ends of the first platform 3 and the movable ladder frame 5. Two groups of the first fences 10 are respectively fixedly connected to the first platform 3 and the movable ladder frame 5. Multiple groups of universal wheels 6 are provided at the lower end of the movable ladder frame 5 for supporting the movement of the movable ladder frame 5 on the ship's side.

[0031] Furthermore, a second fence 11 for preventing personnel from falling is provided along the upper ends of the second platform 4 and the fixed ladder frame 7. The second fence 11 is fixedly connected to the second platform 4 and the fixed ladder frame 7.

[0032] The adjustable boarding ladder adopts a double-layer structure. The second platform 4 is the first layer, and the first platform 3 is the second layer. The fixed ladder frame 7 is fixed to the second platform 4. One can board the second platform 4 through the fixed ladder frame 7 and board the first platform 3 through the movable ladder frame 5. The first platform 3 and the second platform 4 are connected through a climbing passage. The movable ladder frame 5 is hinged to the first platform 3. The lifting member is used to control the lifting of the movable ladder frame 5 to adjust the set height of the movable ladder frame 5. The rotating control device is used to control the rotation of the movable column 2, so that the movable ladder frame 5 can be smoothly placed on the ship's side in different directions, with high flexibility. The first platform 3 is connected to the second platform 4 through a climbing passage. In addition to the fixed ladder frame 7 provided on the second platform 4, an escape passage is also provided below the second platform 4. When there is congestion on the second platform 4, personnel can be diverted through the escape passage, which can effectively reduce the occurrence of trampling. The rotation of the movable column 2 is restricted by the pawl limit device to provide safety guarantee for escape.

[0033] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed. The scope of protection claimed by the present invention is defined by the appended claims and their equivalents.

Claims

1. An adjustable boarding ladder, comprising a frame structure and a support structure, wherein the support structure comprises a support tube (1) and a movable column (2), wherein the movable column (2) is rotatably connected to the upper end of the support tube (1), and is characterized in that: A rotation control device is provided at the connection between the support cylinder (1) and the movable column (2); The frame structure comprises a first platform (3) and a second platform (4), wherein the first platform (3) is fixedly connected to the outside of the movable column (2), and the second platform (4) is fixedly connected to the outside of the support tube (1), and the first platform (3) is placed above the second platform (4); A movable ladder frame (5) is provided on one side of the first platform (3), the movable ladder frame (5) is hinged to the first platform (3), and a lifting member for controlling the rise and fall of the movable ladder frame (5) is provided at the upper end of the movable column (2); A fixed ladder frame (7) is provided on one side of the second platform (4), and the fixed ladder frame (7) is fixedly connected to the second platform (4). A climbing passage is provided between the first platform (3) and the second platform (4), and an escape passage is provided below the second platform (4). A ratchet limit device is provided on the outer side of the support tube (1), and the ratchet limit device is placed between the first platform (3) and the second platform (4) and is used to limit the rotation of the movable column (2) to ensure safe escape.

2. The adjustable boarding ladder according to claim 1, characterized in that: The rotation control device comprises a positioning column (17), a first gear (18), a second gear (19) and a motor (20); the positioning column (17) is fixedly connected to the lower end of the movable column (2); the first gear (18) is sleeved on the outside of the positioning column (17); the positioning column (17) is fixedly connected to the first gear (18); the motor (20) is fixedly connected to the inside of the support tube (1); the output end of the motor (20) is fixedly connected to the second gear (19); and the second gear (19) is meshed with the first gear (18).

3. The adjustable boarding ladder according to claim 1, characterized in that: The lifting member comprises a support plate (8) and hydraulic telescopic rods (9) arranged on the left and right sides of the movable ladder frame (5); the support plate (8) is fixedly connected to the upper end of the movable column (2); the mounting end of the hydraulic telescopic rod (9) is hinged to the support plate (8); and the output end of the hydraulic telescopic rod (9) is hinged to the upper end of the movable ladder frame (5).

4. The adjustable boarding ladder according to claim 2, characterized in that: The ratchet limiting device comprises a ratchet (21), an operating window (16), a rotating shaft (31), a pawl (32) and a worm gear mechanism (33); the ratchet (21) is sleeved on the outside of a positioning column (17); the positioning column (17) is fixedly connected to the ratchet (21); the operating window (16) is opened on the outside of a support tube (1); the rotating shaft (31) is rotatably arranged on the inside of the operating window (16); a pawl (32) is fixedly connected to the outside of the rotating shaft (31); the pawl (32) cooperates with the ratchet (22) arranged on the outside of the ratchet (21); and a worm gear mechanism (33) for controlling the rotation of the rotating shaft (31) is arranged in the operating window (16).

5. The adjustable boarding ladder according to claim 1, characterized in that: The climbing passage comprises a first window (12) and a movable ladder (13); the first window (12) is opened at the lower end of the first platform (3); the movable ladder (13) is fixedly connected to the lower end of the first platform (3); a first bracket (25) and a first diagonal support frame (26) are respectively provided on the left and right sides of the movable ladder (13); the first bracket (25) and the first diagonal support frame (26) are fixedly connected to the movable ladder (13); and the first bracket (25) and the first diagonal support frame (26) are fixedly connected to the lower end of the first platform (3).

6. The adjustable boarding ladder according to claim 5, characterized in that: A first opening window (23) is provided outside the first window (12); one end of the first opening window (23) is hinged to the upper end of the first platform (3) via a pivot; the other end of the first opening window (23) is provided with a first buckle (24); the first buckle (24) is buckled with a slot provided on the upper end of the first platform (3).

7. The adjustable boarding ladder according to claim 1, characterized in that: The escape passage comprises a second window (14) and a fixed ladder (15) fixed on the ground, wherein the second window (14) is opened at the lower end of the movable ladder frame (5), the upper end of the fixed ladder (15) is fixedly connected to the lower end of the movable ladder frame (5), and the left and right sides of the fixed ladder (15) are respectively provided with a second bracket (29) and a second diagonal brace (30), the second bracket (29) and the second diagonal brace (30) are fixedly connected to the fixed ladder (15), and the second bracket (29) and the second diagonal brace (30) are fixedly connected to the lower end of the second platform (4).

8. The adjustable boarding ladder according to claim 7, characterized in that: A second opening window (27) is provided outside the second window (14); one end of the second opening window (27) is hinged to the upper end of the second platform (4) via a pivot; the other end of the second opening window (27) is provided with a second buckle (28); the second buckle (28) is buckled with a slot provided on the upper end of the second platform (4).

9. The adjustable boarding ladder according to claim 1, characterized in that: A first fence (10) for preventing people from falling is provided at the upper ends of the first platform (3) and the movable ladder frame (5); two groups of the first fences (10) are fixedly connected to the first platform (3) and the movable ladder frame (5) respectively; and a plurality of groups of universal wheels (6) are provided at the lower end of the movable ladder frame (5).

10. An adjustable boarding ladder according to any one of claims 1 to 9, characterized in that: A second fence (11) for preventing people from falling is provided along the upper ends of the second platform (4) and the fixed ladder frame (7); the second fence (11) is fixedly connected to the second platform (4) and the fixed ladder frame (7).

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