Crawling ladder device special for trestle overhauling

Abstract

The utility model discloses a special ladder stand device for maintenance of a trestle, which comprises a lifting platform, a ladder stand, a ladder stand and a ladder stand, the safety door is movably arranged at the notch, and a locking mechanism is arranged between the safety door and the lifting platform; the lifting platform is positioned below the lifting platform; the vertical ladder is connected between the lifting platform and the cantilever platform, and a connecting component fixed to the middle of the trestle is fixed to the vertical ladder; the surfaces of the lifting platform, the lifting platform and the vertical ladder are respectively coated with a protective coating; the method has the advantage that the operation safety and efficiency in complex and severe environments can be remarkably improved.

Description

Technical Field

[0001] The utility model relates to the technical field of ladders, in particular to a special ladder device for trestle maintenance. Background Art

[0002] As a common structure in ports, docks and bridge projects, piers have the important function of connecting water and land, facilitating cargo loading and unloading and personnel passage. With the rapid development of modern logistics and transportation, the maintenance and overhaul of piers are becoming more and more frequent. The safe and efficient arrival of maintenance personnel at the work location has become an issue that cannot be ignored. Traditional maintenance methods usually rely on temporary scaffolding or fixed maintenance facilities. These methods are not only time-consuming and labor-intensive, but also often difficult to ensure the safety of operators in complex and changeable working environments.

[0003] In recent years, although a variety of pier maintenance auxiliary facilities such as folding maintenance ladders and slide-guided maintenance platforms have emerged on the market, they have made certain progress in promoting maintenance efficiency and safety assurance, but they still face several key challenges, especially those related to safety and environmental adaptability. These problems cannot be ignored: the primary problem is that the existing maintenance ladder design fails to fully adapt to the extreme environmental conditions of the pier. The pier is often exposed to natural factors such as strong winds and sea breezes, which makes the structure of ordinary maintenance ladders susceptible to erosion, weakened stability, and greatly reduced durability. In this environment, corrosion accelerates material aging, increases the risk of structural failure, and seriously threatens operators. Secondly, the limitations of existing equipment in terms of operational convenience and flexibility have become a major obstacle in emergency response and special maintenance situations. When faced with emergencies, maintenance personnel often find it difficult to quickly start work due to slow equipment deployment or difficult positioning. This not only affects maintenance efficiency, but also significantly increases safety risks when time is tight; more importantly, the lack of safety protection measures on many maintenance ladders is worrying. For example, the lack of eye-catching safety warning signs and safety doors makes it difficult for other staff or equipment operators to identify the maintenance area in visually restricted or busy working scenarios, increasing the possibility of collision or mistaken entry into dangerous areas.

[0004] In summary, the existing trestle maintenance ladder equipment still has significant room for improvement in terms of durability in complex environments, flexible and efficient operation support, and critical safety protection design. Therefore, it is imperative to develop a new maintenance ladder system that can fully meet the unique environmental challenges of the trestle, ensure convenient and flexible operation, and have a built-in strict safety protection mechanism. Utility Model Content

[0005] The purpose of the utility model is to solve the above problems and provide a special ladder device for trestle maintenance, which can significantly enhance the safety and efficiency of operations in complex and harsh environments.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a special ladder device for trestle maintenance, comprising

[0007] A hanging platform is used to be fixed to the upper end of the trestle, and a notch is provided on the hanging platform;

[0008] A safety door is movably arranged at the notch and a locking mechanism is arranged between the safety door and the hanging platform;

[0009] A cantilever platform, located below the hanging platform;

[0010] A straight ladder is connected between the hanging platform and the cantilever platform, and a connecting member fixed to the middle part of the trestle is fixed on the straight ladder;

[0011] The surfaces of the hanging platform, the cantilever platform and the straight ladder are respectively coated with protective coatings.

[0012] Preferably, the hanging platform includes two first cross beams and two second cross beams, the two first cross beams are spaced apart vertically, the two second cross beams are spaced apart vertically, the first cross beams and the corresponding second cross beams are horizontally spaced apart, the two first cross beams are connected by a plurality of first longitudinal beams, the two second cross beams are connected by a plurality of second longitudinal beams, a pedal is connected between the first cross beam located below and the second cross beam located below, the upper end of the straight ladder is connected between the two first cross beams and the two second cross beams, and a ladder entrance is formed between the pedal and the straight ladder.

[0013] Preferably, the pedal is welded on the trestle, and a pattern is provided on the upper surface of the pedal.

[0014] Preferably, one side of the safety door is hinged to one side of the hanging platform through a hinge assembly, and the locking mechanism includes a lock buckle and a lock tongue that can be interlocked, the lock buckle is arranged on the safety door, and the lock tongue is arranged on the other side of the hanging platform.

[0015] Preferably, the cantilever platform includes two third cross beams and two fourth cross beams, the two third cross beams are spaced apart vertically, the two fourth cross beams are spaced apart vertically, the third cross beams and the corresponding fourth cross beams are horizontally spaced apart, the two third cross beams are connected by a plurality of third longitudinal beams, the two fourth cross beams are connected by a plurality of fourth longitudinal beams, a platform plate is connected between the third cross beam located below and the fourth cross beam located below, a reinforcing beam is connected between the third cross beam located above and the front side of the fourth cross beam located above, and the lower end of the straight ladder is connected between the two third cross beams and the two fourth cross beams.

[0016] Preferably, a plurality of supporting beams are connected between the third cross beam located below and the fourth cross beam located below, and the platform plate is connected to the plurality of supporting beams.

[0017] Preferably, the straight ladder further includes a first side beam and a second side beam, the first side beam being connected between the third beam above and the first beam below, and the second side beam being connected between the fourth beam above and the second beam below.

[0018] Preferably, the connecting member comprises a plurality of bent steel bars for welding on the trestle, and one end of the plurality of bent steel bars is welded to the straight ladder.

[0019] Preferably, a warning sign is provided on the safety door.

[0020] Compared with the prior art, the advantages of the utility model are: the core design of the present invention includes a sturdy hanging platform, which can be firmly connected to the upper end of the pier, and a gap is specially designed for personnel to enter and exit. The gap is equipped with a safety door and a locking mechanism to ensure the closure and safety during maintenance and prevent unauthorized entry. At the same time, it also provides a clear entry and exit channel for maintenance personnel. A cantilever platform is configured under the hanging platform, and the cantilever platform is located under the pier, providing a stable support platform for maintenance personnel. In addition, combined with the straight ladder between the two, a stable and direct up and down passage is constructed. Connecting components are also specially fixed on the straight ladder to ensure a firm connection with the main structure of the pier, thereby enhancing the overall stability and load-bearing capacity.

[0021] What is particularly critical is that all exposed surfaces of the device are coated with a high-performance protective coating. This design effectively resists the erosion of materials by extreme environmental factors such as strong winds and salt spray, significantly improves the weather resistance and service life of the equipment, and reduces the risk of structural failure due to corrosion, thereby ensuring long-term reliability and safety.

[0022] In addition, the design of the ladder system focuses on the convenience and flexibility of operation. The setting of safety doors and eye-catching safety warning signs not only strengthen the safety management on site, but also effectively avoid misoperation and accidental collisions during operation, ensuring the safety of all personnel on the pier. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art are briefly introduced below. It is obvious that the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0024] Figure 1 This is a three-dimensional structure diagram of the utility model. Figure 1 ;

[0025] Figure 2 This is a three-dimensional structure diagram of the utility model. Figure 2 ;

[0026] Figure 3 It is a side view of the utility model;

[0027] In the figure, 1. hanging platform; 2. notch; 3. safety door; 4. locking mechanism; 5. cantilever platform; 6. straight ladder; 7. connecting member; 8. protective coating; 9. first horizontal beam; 10. second horizontal beam; 11. first longitudinal beam; 12. second longitudinal beam; 13. pedal; 14. ladder entrance; 15. hinge assembly; 16. lock; 17. lock tongue; 18. third horizontal beam; 19. fourth horizontal beam; 20. third longitudinal beam; 21. fourth longitudinal beam; 22. platform plate; 23. reinforcement beam; 24. support beam; 25. first side beam; 26. second side beam; 27. bent steel bars; 28. warning sign. DETAILED DESCRIPTION

[0028] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0029] Embodiment 1: As shown in the figure, a ladder device for trestle maintenance includes:

[0030] The hanging platform 1 is used to be fixed to the upper end of the trestle, and a notch 2 is provided on the hanging platform 1;

[0031] A safety door 3 is movably arranged at the notch 2, and a locking mechanism 4 is arranged between the safety door 3 and the hanging platform 1;

[0032] The cantilever platform 5 is located below the hanging platform 1;

[0033] A straight ladder 6 is connected between the hanging platform 1 and the cantilever platform 5, and a connecting member 7 fixed to the middle part of the trestle is fixed on the straight ladder 6;

[0034] The surfaces of the hanging platform 1 , the cantilever platform 5 and the straight ladder 6 are coated with a protective coating 8 respectively.

[0035] Embodiment 2: As shown in the figure, different from Embodiment 1, the hanging platform 1 includes two first cross beams 9 and two second cross beams 10, the two first cross beams 9 are spaced apart in the upper and lower parts, the two second cross beams 10 are spaced apart in the upper and lower parts, the first cross beams 9 and the corresponding second cross beams 10 are spaced apart in the horizontal direction, the two first cross beams 9 are connected by a plurality of first longitudinal beams 11, the two second cross beams 10 are connected by a plurality of second longitudinal beams 12, a pedal 13 is connected between the first cross beam 9 located at the bottom and the second cross beam 10 located at the bottom, the upper end of the straight ladder 6 is connected between the two first cross beams 9 and the two second cross beams 10, and a ladder entrance 14 is formed between the pedal 13 and the straight ladder 6.

[0036] In the above structure, the main body of the hanging platform 1 is composed of two groups of beams spaced apart from each other, namely, two first beams 9 and two second beams 10. Between each group of first beams 9, they are connected to each other by multiple first longitudinal beams 11, and between each group of second beams 10, they are connected to each other by multiple second longitudinal beams 12, forming two planar support grid structures. On the one hand, this grid design enables the entire hanging platform 1 to obtain sufficient rigidity and load capacity, and can reliably support various forces applied to it by maintenance operations; on the other hand, it is also conducive to reducing its own weight and facilitating lifting and disassembly operations. It is worth noting that a pedal 13 is also connected between the first beam 9 and the second beam 10 located below, forming a platform for personnel to pass, and the upper end of the straight ladder 6 is fixed between the two first beams 9 and the two second beams 10 by welding, so that the pedal 13 and the entrance part of the straight ladder 6 can be seamlessly connected, and maintenance personnel can naturally transition to the ladder operation area.

[0037] This design is not only structurally reasonable, but more importantly, it improves the safety and convenience of maintenance work. Since the frame of the hanging platform 1 adopts a stable grid structure, it can reliably support the maintenance personnel and the tools and equipment they carry; at the same time, the seamless connection between the pedal 13 and the ladder avoids the risk of falling due to the height difference of the steps when the maintenance personnel enter and exit the work area, greatly increasing the safety of passage.

[0038] In this embodiment, the pedal 13 is welded on the trestle, and the upper surface of the pedal 13 is provided with a pattern.

[0039] Firstly, welding the pedal 13 directly to the trestle can greatly improve the stability and carrying capacity of the whole device. As the main working platform for maintenance personnel, the pedal 13 needs to bear the weight of the human body and the load of tools. It is directly connected to the main body of the trestle, which can make the most of the structural strength of the trestle itself, thereby obtaining sufficient load capacity and avoiding dangerous vibration or displacement during operation; secondly, the anti-slip pattern arranged on the upper surface of the pedal 13 can effectively increase the friction between it and the soles of the maintenance personnel, thereby greatly improving the grip performance and anti-slip effect of the pedal 13. The maintenance working environment is complex, and the surface of the trestle may be slipping due to moisture, salt spray and other factors. Once a slip occurs, it is very easy to cause personal injury. The anti-slip pattern can provide reliable support for the maintenance personnel in this case, ensure their firm footing, and fundamentally eliminate the hidden dangers of safety accidents caused by slipping and falling.

[0040] In this embodiment, one side of the safety door 3 is hinged to one side of the hanging platform 1 through a hinge assembly 15, and the locking mechanism 4 includes a lock buckle 16 and a lock tongue 17 that can be interlocked. The lock buckle 16 is arranged on the safety door 3, and the lock tongue 17 is arranged on the other side of the hanging platform 1.

[0041] In the above structure, one side of the safety door 3 is hinged to one side of the hanging platform 1 through a hinge assembly 15, and can be opened and closed. When it is necessary to enter the working area, the maintenance personnel can push the safety door 3 to the side, so as to facilitate entering the straight ladder 6 area through the pedal 13 of the hanging platform 1. After the work is completed, the safety door 3 can be automatically closed to prevent people from accidentally falling from the ladder entrance 14.

[0042] In order to ensure the reliability of the safety door 3 when it is closed, a special locking mechanism 4 is set on the hanging platform 1. The locking mechanism 4 includes a lock buckle 16 on one side of the safety door 3 and a lock tongue 17 on the other side of the hanging platform 1. When the safety door 3 is closed, the lock buckle 16 and the lock tongue 17 can be accurately buckled together, so that the door body and the hanging platform 1 frame form a firmly locked state to prevent the door body from shaking or accidentally popping open during operation. The design of this lock buckle 16 and lock tongue 17 has the advantages of simple structure and high reliability. They are made of solid metal materials and can withstand large Tension and torque can be achieved, thereby ensuring the strength and durability of the buckling position during long-term use. At the same time, the buckling mechanism is clear and easy to use. The maintenance personnel only need to push it easily to switch the safety door 3 from the open state to the closed and locked state. The operation is convenient and efficient. It is worth mentioning that by arranging the lock buckle 16 and the lock tongue 17 on different sides of the safety door 3 and the hanging platform 1 respectively, all-round enclosure protection can be formed in the closed state, thereby completely eliminating the risk of falling caused by the shaking of the safety door 3, and providing solid hardware protection for the personal safety of the maintenance personnel.

[0043] In summary, the movable locking design of the safety door 3 and the suspension platform 1 achieves a high degree of unity between operational convenience and safety protection. By integrating various structural elements such as hinges and fastener locking, the prohibited areas of the maintenance operation area are fully ensured, thus ensuring the safety of maintenance personnel from a hardware level.

[0044] Embodiment 3: As shown in the figure, different from Embodiment 2, the platform 5 includes two third cross beams 18 and two fourth cross beams 19, the two third cross beams 18 are spaced apart from each other, the two fourth cross beams 19 are spaced apart from each other, the third cross beams 18 and the corresponding fourth cross beams 19 are spaced apart horizontally, the two third cross beams 18 are connected by a plurality of third longitudinal beams 20, the two fourth cross beams 19 are connected by a plurality of fourth longitudinal beams 21, a platform plate 22 is connected between the third cross beam 18 located below and the fourth cross beam 19 located below, a reinforcing beam 23 is connected between the third cross beam 18 located above and the front side of the fourth cross beam 19 located above, and the lower end of the straight ladder 6 is connected between the two third cross beams 18 and the two fourth cross beams 19.

[0045] The platform 5 of the special ladder device for trestle maintenance adopts a gridded space structure design similar to the hanging platform 1, and is composed of two layers of horizontal beams and longitudinal beams to form a frame. On the basis of reasonable structure and high strength, it also incorporates strengthening measures and platforms to ensure the safety and convenience of operation. The specific design is as follows:

[0046] The basic frame of the platform 5 is composed of two groups of third beams 18 and fourth beams 19 spaced apart from each other. Each group of beams is connected by multiple longitudinal beams to form two plane grid structures. This grid design gives the platform 5 excellent overall rigidity and bearing capacity, and can reliably support the weight load of maintenance personnel and equipment. A platform plate 22 is also connected between the third beam 18 and the fourth beam 19 below, providing a stable working plane for maintenance personnel. Maintenance personnel can stay, transfer or store tools on this platform conveniently, which greatly facilitates maintenance work. Another highlight In particular, a reinforcing beam 23 is added to the front side of the third cross beam 18 and the fourth cross beam 19 located above, which provides additional reinforcement and load-bearing effect on the entire frame. This design is very necessary because the lower end of the straight ladder 6 needs to be fixed between the upper cross beams through a special connection method, and the force will be concentrated here. The existence of the reinforcing beam 23 can effectively disperse and transfer these loads, avoiding excessive local stress and causing structural instability, and cooperates with the third cross beam 18 and the fourth cross beam 19 located above to enclose a relatively safe working area, thereby ensuring the safety of maintenance personnel.

[0047] In this embodiment, a plurality of support beams 24 are connected between the third cross beam 18 located at the bottom and the fourth cross beam 19 located at the bottom, and the platform plate 22 is connected to the plurality of support beams 24 .

[0048] The setting of the support beam 24 provides sufficient support strength and bearing capacity for the platform plate 22. The platform plate 22 needs to bear the active load of the maintenance personnel and the weight of the tools and equipment. If the platform plate 22 is simply connected between the beams, it is very easy to produce uneven deformation or sagging in the middle part, affecting the performance. The addition of multiple support beams 24 makes the support points of the platform plate 22 more dispersed and the force more uniform, thereby significantly improving the rigidity and bearing capacity of the platform, ensuring that the platform remains flat and stable under the load. In addition, the setting of the support beam 24 also enhances the longitudinal stability of the overall structure of the platform 5. Since the lower end of the straight ladder 6 needs to be connected to the top of the platform 5, a certain horizontal thrust and torque will be generated during the ladder operation. The transmission path of these forces needs to pass through the platform 5 structure. After adding the support beam 24, the transmission routes of each force are more reasonable, avoiding excessive local stress, thereby effectively preventing the entire platform 5 from being twisted and displaced during the force process, and ensuring the smooth progress of the maintenance operation.

[0049] In this embodiment, the straight ladder 6 also includes a first side beam and a second side beam 26. The first side beam 25 is connected between the upper third beam 18 and the lower first beam 9, and the second side beam 26 is connected between the upper fourth beam 19 and the lower second beam 10.

[0050] The first side beam 25 and the second side beam 26 are set to firmly connect the two key components, the hanging platform 1 and the cantilever platform 5, so that they become an integrated spatial bearing system. During the maintenance operation, the load from the activities of the maintenance personnel and the straight ladder 6 itself will be transmitted and distributed through this system, thereby ensuring the structural integrity and stability of the entire device. The first side beam 25 and the second side beam 26 themselves use high-strength components that can withstand large tension and pressure, ensuring the connection reliability at key nodes; secondly, the connection frame formed by the first side beam 25 and the second side beam 26 provides all-round support and positioning for the straight ladder 6. The upper and lower ends of the straight ladder 6 are connected to the hanging platform 1 and the cantilever platform 5 respectively, and the middle part is fixed to the bridge through the connecting member 7. Under this multi-point constraint condition, the straight ladder 6 obtains extremely high spatial stability, will not produce violent swings or twisting deformation, and provides a safe and reliable way for maintenance operations.

[0051] In this embodiment, the connecting member 7 includes a plurality of bent steel bars 27 for welding on the trestle, and one end of the plurality of bent steel bars 27 is welded to the straight ladder 6 .

[0052] The connecting member 7 is composed of a plurality of bent steel bars 27, one end of which is fixed to the side or bottom position of the straight ladder 6 by welding, or fixed to the side of the first side beam 25 and the second side beam 26, and the other end is welded to the bottom or side member of the trestle bridge body. The bent steel bars 27 adopt stiffening ribs or similar forms to form a certain angle and rigidity, so that the straight ladder 6 can be reliably connected to the trestle bridge body. The advantages of this connection method are: first, the bent steel bars 27 as connecting members have a simple structure and are easy to manufacture. It only needs to be properly processed and bent for ordinary straight steel bars, and there is no need to use complex custom parts, thereby greatly reducing the cost and processing difficulty. Secondly, the arrangement of the plurality of bent steel bars 27, The force at the connection position is made more evenly dispersed, avoiding the risk of connection failure caused by excessive local stress, and at the same time improving the torsion resistance of the entire system, ensuring the spatial position stability of the straight ladder 6 during use. Furthermore, by directly welding the steel bars to the beam structure, the stiffness and strength of the trestle itself can be maximized, so that the connection nodes can obtain sufficient bearing capacity, and the welding points can also be reinforced and maintained at any time to ensure the reliability of the connection. In addition, this connection method is also highly adaptable. Due to the adjustability of the bent steel bars 27, it can adapt to different types of trestle structures, and the position of the connection point can also be flexibly adjusted, so that the entire system can fit different bridge types and achieve the best layout.

[0053] In this embodiment, a warning sign 28 is provided on the safety door 3, thereby further enhancing safety.

[0054] In this embodiment, all components are made of steel. In order to improve the corrosion resistance and service life of the entire device, a protective coating is applied to the outer surface of the device. This coating material usually adopts zinc-rich anti-corrosion coatings such as zinc-rich primer or epoxy zinc-rich primer. Zinc-rich coatings have zinc powder as the main component and have excellent cathodic protection effects. When the base metal is exposed due to corrosion or other reasons, the surrounding zinc powder will preferentially undergo electrochemical reactions to form zinc oxide, thereby preventing the iron-based base material from further corrosion. At the same time, the zinc-rich coating itself also has good shielding and barrier effects, avoiding corrosive media such as air and moisture from directly corroding the metal base material, thereby effectively extending its service life and reducing the workload of daily maintenance, thereby reducing the overall operating cost.

[0055] The above description is only a preferred embodiment of the utility model and is not intended to limit the utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the utility model should be included in the protection scope of the utility model.

Claims

1. A special ladder device for trestle maintenance, characterized in that: include A hanging platform is used to be fixed to the upper end of the trestle, and a notch is provided on the hanging platform; A safety door is movably arranged at the notch and a locking mechanism is arranged between the safety door and the hanging platform; A cantilever platform, located below the hanging platform; A straight ladder is connected between the hanging platform and the cantilever platform, and a connecting member fixed to the middle part of the trestle is fixed on the straight ladder; The surfaces of the hanging platform, the cantilever platform and the straight ladder are respectively coated with protective coatings.

2. A ladder device for trestle maintenance according to claim 1, characterized in that: The hanging platform includes two first cross beams and two second cross beams, the two first cross beams are spaced apart from each other up and down, the two second cross beams are spaced apart from each other up and down, the first cross beams and the corresponding second cross beams are spaced apart from each other horizontally, the two first cross beams are connected by a plurality of first longitudinal beams, the two second cross beams are connected by a plurality of second longitudinal beams, a pedal is connected between the first cross beam located below and the second cross beam located below, the upper end of the straight ladder is connected between the two first cross beams and the two second cross beams, and a ladder entrance is formed between the pedal and the straight ladder.

3. A ladder device for trestle maintenance according to claim 2, characterized in that: The pedal is welded on the trestle, and the upper surface of the pedal is provided with a pattern.

4. A ladder device for trestle maintenance according to claim 1, characterized in that: One side of the safety door is hinged to one side of the hanging platform through a hinge assembly, and the locking mechanism includes a lock buckle and a lock tongue that can be buckled with each other. The lock buckle is arranged on the safety door, and the lock tongue is arranged on the other side of the hanging platform.

5. A ladder device for trestle maintenance according to claim 2, characterized in that: The cantilever platform includes two third cross beams and two fourth cross beams, the two third cross beams are spaced apart from each other up and down, the two fourth cross beams are spaced apart from each other up and down, the third cross beams and the corresponding fourth cross beams are horizontally spaced apart, the two third cross beams are connected by a plurality of third longitudinal beams, the two fourth cross beams are connected by a plurality of fourth longitudinal beams, a platform plate is connected between the third cross beam located below and the fourth cross beam located below, a reinforcing beam is connected between the third cross beam located above and the front side of the fourth cross beam located above, and the lower end of the straight ladder is connected between the two third cross beams and the two fourth cross beams.

6. A ladder device for trestle maintenance according to claim 5, characterized in that: A plurality of supporting beams are connected between the third cross beam located at the bottom and the fourth cross beam located at the bottom, and the platform plate is connected to the plurality of supporting beams.

7. A ladder device for trestle maintenance according to claim 6, characterized in that: The straight ladder further includes a first side beam and a second side beam, wherein the first side beam is connected between the third cross beam at the top and the first cross beam at the bottom, and the second side beam is connected between the fourth cross beam at the top and the second cross beam at the bottom.

8. The special ladder device for trestle maintenance according to claim 1, characterized in that: The connecting member comprises a plurality of bent steel bars for welding on the trestle, and one end of the plurality of bent steel bars is welded on the straight ladder.

9. The special ladder device for trestle maintenance according to claim 1, characterized in that: The safety door is provided with a warning sign.

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