A special transport bucket for sugarcane field

Abstract

The utility model relates to transportation equipment technical field, concretely is a kind of special transport bucket in sugarcane field, including bucket body, tractor connecting component and anti-drop fixing mechanism;Tractor connecting component is set in the front end of bucket body, including the quick-release connector of adaptation tractor rear suspension interface and angle adjusting mechanism;Anti-drop fixing mechanism includes telescopic guardrail and end limit stopper being set along the two side edges of bucket body, end limit stopper is located inside the vertical setting of bucket body, and the upper end of end limit stopper is connected and fixed with one end of telescopic guardrail.The special transport bucket in sugarcane field in it, by setting the quick-release connector of adaptation tractor rear suspension interface, without tedious bolt disassembly, realize the quick docking and separation of transport bucket and tractor, greatly improve field work equipment switching efficiency;Collaborate angle adjusting mechanism, the pitch angle of bucket body and tractor can be flexibly adjusted, perfect adaptation sugarcane field hilly slope, complex terrain of muddy plot.

Description

Technical Field

[0001] This utility model relates to the field of transportation equipment technology, specifically to a special transport container for sugarcane fields. Background Technology

[0002] Sugarcane, an important economic crop in southern my country, is characterized by its long, slender structure (2-4 meters in length) and heavy weight, placing special demands on the adaptability, safety, and efficiency of post-harvest transportation equipment. Currently, sugarcane field transportation mainly relies on ordinary agricultural transport containers, simple troughs, or manual labor, which presents the following key problems:

[0003] Insufficient adaptability and high crop loss: The length and width of the trough of ordinary transport containers are not compatible with the characteristics of sugarcane, which means that sugarcane needs to be bent and placed when loaded, which can easily cause the sugarcane stalks to break and the skin to be damaged; the inner wall of the trough is smooth, and the sugarcane is violently shaken and collided during transportation, which further aggravates the damage, and at the same time, it is easy to cause the center of gravity to shift.

[0004] Inconvenient connection and adjustment, and poor adaptability in the field: Sugarcane fields are mostly hilly slopes or muddy areas. The existing transport buckets are mostly connected to the tractors by fixed bolts, which is cumbersome to disassemble and lacks angle adjustment function. When the slope is large, the bucket cannot be kept level, and the sugarcane is easy to slide and fall off. Some connection structures are not strong enough and are easy to loosen and shift during transportation, posing a safety hazard.

[0005] Inadequate anti-slip protection and low safety: Traditional transport bucket guardrails are of fixed height and cannot be flexibly adjusted according to the load. When the load is large, they are difficult to effectively prevent sugarcane from sliding off the sides. Most guardrails lack reflective markings, which increase the risk of operation at night or in the early morning. Utility Model Content

[0006] The purpose of this utility model is to provide a special transport bucket for sugarcane fields, in order to solve the problem that the length and width of the trough of the ordinary transport bucket mentioned in the background art are not matched with the characteristics of sugarcane, which leads to the sugarcane needing to be bent and placed when loaded, which easily causes the sugarcane stalks to break and the skin to be damaged; the inner wall of the trough is smooth, and the sugarcane is violently shaken and collided during transportation, which further aggravates the damage, and at the same time, it is easy to cause the center of gravity to shift.

[0007] To achieve the above objectives, this utility model provides a special transport bucket for sugarcane fields, including a bucket body, a tractor connection assembly, and an anti-detachment fixing mechanism; the tractor connection assembly is located at the front end of the bucket body and includes a quick-release connector adapted to the tractor's rear suspension interface and an angle adjustment mechanism; the anti-detachment fixing mechanism includes retractable guardrails and end limiting blocks arranged along both sides of the bucket body, the retractable guardrails having a retraction stroke of 0.5-1.2m, and the end limiting blocks being vertically arranged inside the bucket body, with the upper end of the end limiting blocks being connected and fixed to one end of the retractable guardrails.

[0008] This feature utilizes a quick-release connector adapted to the tractor's rear suspension interface, eliminating the need for cumbersome bolt removal and allowing for rapid docking and disassembly of the transport bucket and tractor, significantly improving the efficiency of equipment switching in field operations. Combined with an angle adjustment mechanism, the pitch angle between the bucket and the tractor can be flexibly adjusted, perfectly adapting to the complex terrain of sugarcane fields, including hilly slopes and muddy areas. This ensures the bucket remains relatively level when driving on slopes, preventing sugarcane from sliding and falling due to terrain inclination, significantly enhancing the equipment's field adaptability. The retractable guardrail features a length-adjustable design. Combined with its upper fixing structure with the end limit stop, adjusting the guardrail length simultaneously moves the end limit stop along the length of the bucket, precisely accommodating sugarcane of different lengths. This solves the problem of traditional fixed-length transport buckets being unable to accommodate differences in sugarcane length, leading to bent placement or end shifting, allowing sugarcane of different lengths to be placed straight, fundamentally reducing losses from broken stalks and damaged skin.

[0009] Preferably, the trough is an open-mouthed trough adapted to the long, narrow structure of sugarcane, with a length of 3-6m and a width of 1.2-1.8m, and the inner wall of the trough is provided with anti-slip protrusions.

[0010] This design features an open-top trough that is sized to fit the long, thin sugarcane, allowing for straight loading without bending and reducing damage to the sugarcane stalks. The anti-slip protrusions on the inner wall increase friction, preventing the sugarcane from sliding and colliding during transport and improving transport stability.

[0011] Preferably, the angle adjustment mechanism can achieve a pitch angle adjustment of 0-15° between the bucket and the tractor, including a drive screw, a moving block, and a wedge block. The wedge block is installed on the end of the bucket, and the drive screw drives the moving block to move horizontally, cooperating with the lower inclined surface of the wedge block to achieve the angle adjustment of the bucket.

[0012] This design, featuring a screw-wedge block combination, enables precise pitch adjustment from 0-15°, adapting to sloping terrain and ensuring the bucket remains level. The structure offers smooth transmission, high strength, and protection against bumps and loosening, enhancing its adaptability in the field.

[0013] Preferably, the bottom of the bucket is provided with a discharge mechanism, which includes a hydraulic push rod and a movable bottom plate. One end of the hydraulic push rod is hinged to the bottom of the bucket, and the other end is connected to the movable bottom plate. The movable bottom plate can be rotated around the hinge point at the rear end of the bucket, with a rotation angle of 0-45°.

[0014] This feature features a hydraulically driven movable base plate that can rotate from 0 to 45 degrees, providing a large unloading angle and ensuring smooth, jam-free sugarcane sliding. No manual assistance is required; it can be operated by a single person, improving unloading efficiency and reducing labor intensity.

[0015] Preferably, the anti-slip protrusion is a hemispherical structure with a diameter of 10-15mm, the distance between adjacent anti-slip protrusions is 50-80mm, and the anti-slip protrusion is integrally formed with the bucket body.

[0016] The hemispherical anti-slip protrusions are designed with reasonable parameters, providing precise anti-slip effect; the one-piece molded structure is sturdy and not easy to fall off, avoiding scratching the sugarcane, and balancing anti-slip performance with structural reliability.

[0017] Preferably, the retractable guardrail is provided with reflective markings on its outer side.

[0018] This reflective signage reflects light during low-light / nighttime operations, serving as a warning, reducing the risk of collisions, and improving operational safety.

[0019] Preferably, the retractable guardrail includes several movable plates, and telescopic rods are slidably connected between the movable plates. The retractable guardrail can be extended or retracted by the telescopic rods sliding within the movable plates.

[0020] This design features a movable plate and telescopic bar structure, allowing for flexible extension and retraction of the guardrail. Locking bolts ensure a secure fixation after adjustment. It adapts to different loading requirements, is easy to operate, and provides stable protection.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] This sugarcane field transport bucket features a quick-release connector that adapts to the tractor's rear suspension interface, eliminating the need for cumbersome bolt removal and allowing for rapid docking and disassembly between the bucket and the tractor, significantly improving the efficiency of equipment switching in field operations. Combined with an angle adjustment mechanism, the bucket's pitch angle with the tractor can be flexibly adjusted, perfectly adapting to the complex terrain of hilly slopes and muddy areas in sugarcane fields. This ensures the bucket remains relatively level when driving on slopes, preventing sugarcane from sliding and falling due to terrain inclination, and significantly enhancing the equipment's adaptability in the field.

[0023] The retractable guardrail features a length-adjustable design. Combined with its upper fixing structure to the end limit stop, adjusting the guardrail length simultaneously moves the end limit stop along the length of the bucket, precisely accommodating sugarcane of different lengths. This solves the problem of traditional fixed-length transport buckets being unable to accommodate differences in sugarcane length, leading to bent placement or end shifting. It ensures that sugarcane of different lengths can be placed straight, reducing losses from broken stalks and damaged skin at the source.

[0024] A dual anti-slipping system is formed, consisting of "adjustable side railings + end-mounted moving stoppers": the adjustable side railings can flexibly adjust the protection range according to the length and stacking amount of sugarcane, avoiding gaps in lateral protection caused by insufficient railing length; the end-mounted stoppers move synchronously with the railings, precisely fitting the ends of the sugarcane to restrict its forward and backward movement during transportation from the axial direction. Simultaneously, the fixed connection between the stoppers and the railings enhances the overall structural rigidity of the railings, preventing loosening and deformation after adjustment. This dual protective effect significantly reduces the risk of sugarcane slipping and colliding during transportation, minimizing crop loss and road safety hazards. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the bucket body in this utility model;

[0027] Figure 3 This is a schematic diagram of the anti-detachment fixing mechanism in this utility model;

[0028] Figure 4 This is a schematic diagram of the tractor connection assembly in this utility model;

[0029] Figure 5 This is a schematic diagram of the angle adjustment mechanism in this utility model;

[0030] The meanings of the labels in the diagram are as follows:

[0031] 1. Bucket body; 11. Anti-slip protrusions; 2. Tractor connecting assembly; 21. Quick-release connector; 22. Angle adjustment mechanism; 221. Drive screw; 222. Drive screw; 223. Wedge block; 3. Anti-detachment fixing mechanism; 31. Telescopic guardrail; 311. Reflective markings; 32. End limit stop. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] This utility model provides a special transport container for sugarcane fields, such as... Figures 1-3As shown, the device includes a bucket body 1, a tractor connecting assembly 2, and an anti-detachment fixing mechanism 3. The tractor connecting assembly 2 is located at the front end of the bucket body 1 and includes a quick-release connector 21 adapted to the tractor's rear suspension interface and an angle adjustment mechanism 22. The anti-detachment fixing mechanism 3 includes a retractable guardrail 31 and an end limiting block 32 arranged along both sides of the bucket body 1. The retractable guardrail 31 has a retractable stroke of 0.5-1.2m. The end limiting block 32 is located vertically inside the bucket body 1, and the upper end of the end limiting block 32 is connected and fixed to one end of the retractable guardrail 31.

[0034] The quick-release connector 21 is compatible with the tractor's rear suspension interface, eliminating the need for complex bolt disassembly and assembly procedures. This allows for rapid docking and separation of the transport bucket and the tractor, significantly reducing equipment changeover time and improving the efficiency of field operations. The angle adjustment mechanism 22 can flexibly adjust the pitch angle between the bucket 1 and the tractor. For complex terrains such as hilly slopes and muddy areas in sugarcane fields, it ensures that the bucket remains relatively level, preventing sugarcane from sliding and falling due to terrain inclination, and significantly enhancing the equipment's adaptability to complex field conditions. The retractable guardrail 31 has a telescopic stroke of 1.2m, which can flexibly adjust the protection range according to the loading height and load of sugarcane, solving the shortcomings of traditional fixed-height guardrails that cannot adapt to different loading needs. The end limit block 32 is fixedly connected to the upper end of the retractable guardrail 31, forming a synergistic structure of "adjustable protection on both sides + end limit". When the guardrail extends or retracts, it can drive the block to move synchronously, preventing sugarcane from slipping off the side and restricting the sugarcane from moving back and forth axially. The double protection greatly reduces the risk of sugarcane collision and slippage during transportation, and reduces losses such as sugarcane stem breakage and skin damage. The integrated design of the bucket body, connecting components and anti-loosening mechanism is precisely matched to the long and strip-shaped characteristics of sugarcane. The linkage design of the retractable guardrail and the end block allows sugarcane of different lengths to be placed flat, avoiding the sugarcane bending problem caused by the mismatch in length of traditional transport buckets, while not affecting loading operations, taking into account both adaptability and convenience.

[0035] In this embodiment, the hopper 1 is an open trough adapted to the long, narrow structure of sugarcane. The trough is 3-6m long and 1.2-1.8m wide, with anti-slip protrusions 11 on its inner wall. A discharge mechanism is located at the bottom of the hopper 1, comprising a hydraulic push rod and a movable base plate. One end of the hydraulic push rod is hinged to the bottom of the hopper 1, and the other end is connected to the movable base plate. The movable base plate can rotate around the rear hinge point of the hopper 1 at an angle of 0-45°. The anti-slip protrusions 11 are hemispherical with a diameter of 10-15mm, and the distance between adjacent anti-slip protrusions 11 is 50-80mm. The anti-slip protrusions 11 are integrally formed with the hopper 1.

[0036] The open-top trough's length and width are precisely matched to the 2-4m length of individual sugarcane stalks, allowing for straight loading without bending, thus preventing stalk breakage and sugar loss. The open design facilitates bulk loading, while the width balances loading capacity and center of gravity stability, preventing the sugarcane from shifting to either side during loading and causing imbalance. The hemispherical anti-slip protrusions 11 are rationally designed with a diameter (10-15mm) and spacing (50-80mm) to effectively increase the contact friction between the sugarcane and the inner wall of the trough, solving the problem of the smooth, slippery surface of fresh sugarcane and reducing violent shaking and collisions caused by bumps during transportation, further minimizing crop damage. The anti-slip protrusions are integrally molded with the trough body, ensuring high structural strength and preventing detachment, while also avoiding sugarcane jamming or scratches that can occur with spliced ​​structures, balancing anti-slip performance and structural reliability. The hydraulically driven movable bottom plate unloading mechanism can rotate at an angle of 0-45°, which is larger than that of the traditional simple tipping mechanism. It can use gravity to allow sugarcane to slide down quickly and smoothly, avoiding jamming problems caused by its long length and entanglement. The hydraulic drive is easy to operate, requiring no manual assistance for cleaning. One person can complete the unloading operation, which greatly improves unloading efficiency, reduces manpower input, and reduces labor intensity.

[0037] Specifically, the angle adjustment mechanism 22 can realize the pitch angle adjustment between the bucket body 1 and the tractor from 0-15°. It includes a drive screw 221, a moving block 222, and a wedge block 223. The wedge block 223 is installed on the end of the bucket body 1. The drive screw 221 drives the moving block 222 to move horizontally and cooperate with the lower inclined surface of the wedge block 223 to realize the angle adjustment of the bucket body 1.

[0038] The open-top trough's length (3-6m) and width (1.2-1.8m) are precisely matched to the 2-4m length of a single sugarcane stalk, allowing for straight loading without bending, thus preventing sugarcane stalk breakage and sugar loss from the source. The open design facilitates bulk loading of sugarcane, and the width dimension balances loading capacity and center of gravity stability, preventing the sugarcane from shifting to the sides during loading and causing imbalance.

[0039] Significantly improved anti-slip performance and enhanced transportation stability: The hemispherical anti-slip protrusions 11 are rationally designed with a diameter (10-15mm) and spacing (50-80mm), effectively increasing the contact friction between the sugarcane and the inner wall of the trough. This solves the problem of the smooth and slippery surface of fresh sugarcane, reducing the violent shaking and collision of sugarcane during transportation and further reducing crop damage. The anti-slip protrusions are integrally molded with the trough body, which not only has high structural strength and is not easy to fall off, but also avoids the sugarcane jamming or scratching that may be caused by spliced ​​structures, balancing anti-slip performance and structural reliability. The hydraulically driven movable bottom plate unloading mechanism can rotate at an angle of 0-45°, which is larger than the angle of traditional simple tipping bucket mechanisms. It can use gravity to allow the sugarcane to slide down quickly and smoothly, avoiding jamming problems caused by long lengths and entanglement. The hydraulic drive is easy to operate, requiring no manual assistance for cleaning. A single person can complete the unloading operation, greatly improving unloading efficiency, reducing manpower input, and reducing labor intensity.

[0040] Furthermore, the retractable guardrail 31 is provided with reflective markings 311 on its outer side. The retractable guardrail 31 includes several movable plates, and telescopic rods are slidably connected between the movable plates. The retractable guardrail 31 can be extended or retracted by sliding the telescopic rods within the movable plates.

[0041] The reflective markings 311 on the outer side of the retractable guardrail 31 effectively reflect light at night, in the early morning, or in low-light field conditions, providing a clear warning and allowing nearby workers and vehicles to spot the transport equipment in time, avoiding collisions and significantly improving the safety of nighttime field operations. The retractable guardrail adopts a sliding plug-in structure of "several movable plates + telescopic rods," which allows for smooth and flexible extension and retraction, and can be quickly adjusted to adapt to different loading needs. The sliding plug-in design is not only simple in structure and has a low failure rate, but also ensures that the guardrail maintains good structural rigidity after adjustment. With the locking structure (such as the locking bolts mentioned earlier), it can be fixed at any extension position, preventing the guardrail from loosening or shifting during transportation. It balances adjustment flexibility and protective stability, without affecting the convenience of loading and unloading operations.

[0042] When using the sugarcane field-specific transport bucket of this utility model, before operation, the transport bucket is connected to the tractor's rear suspension interface via the quick-release connector 21 at the front end. This eliminates the need for complex bolt disassembly and assembly, quickly completing the fixation and shortening the equipment connection time. Depending on the terrain conditions of the sugarcane field (such as hilly slopes or muddy areas), the attitude of the bucket body 1 is adjusted through the angle adjustment mechanism 22. The drive screw 221 drives the moving block 222 to move horizontally. By utilizing the cooperation between the moving block and the lower inclined surface of the wedge block 223, the horizontal movement is converted into the pitch adjustment of the bucket body, keeping the bucket body relatively horizontal within the range of 0-15°, thus preventing the sugarcane from slipping during subsequent loading or transportation due to terrain inclination.

[0043] Based on the length of the sugarcane to be transported (2-4m) and the estimated load, adjust the anti-detachment fixing mechanism 3: through the sliding connection between the movable plate and the telescopic rod, pull the telescopic guardrail 31 to extend and retract along the length of the bucket (extension stroke 0.5-1.2m), simultaneously driving the end limit block 32 fixedly connected to it to move, so that the block accurately fits the preset position of the sugarcane end; after adjustment, fix the telescopic guardrail with locking bolts to ensure that the protection range is adapted to the length of the sugarcane, forming a double protection layout of "two-sided guardrail + end block"; at the same time, check the reflective markings 311 on the outside of the guardrail to ensure that they are clearly visible, providing warning preparation for nighttime or low-light environments.

[0044] Leveraging the structural advantages of the open-top trough, harvested sugarcane is placed straight into the hopper 1. The trough's length (3-6m) and width (1.2-1.8m) are precisely matched to the long, narrow shape of the sugarcane, allowing for bulk loading without bending and preventing sugarcane stem breakage. During loading, the hopper's width design balances loading capacity and center of gravity stability, preventing the sugarcane from shifting to either side and causing imbalance. The hemispherical anti-slip protrusions 11 (10-15mm in diameter, 50-80mm spacing) on ​​the inner wall of the trough increase the contact friction between the sugarcane and the inner wall, reducing slippage during loading even if the fresh sugarcane has a smooth surface, facilitating rapid stacking.

[0045] When the tractor starts to pull the transport bucket, various mechanisms work together to ensure stability and safety during transport: the angle adjustment mechanism keeps the bucket level, adapting to bumpy and sloping terrain, and preventing the sugarcane from shifting due to terrain tilting; the retractable guardrails block the sugarcane from both sides, and the end limit blocks restrict the axial movement of the sugarcane, providing double protection to prevent the sugarcane from slipping and reducing collision damage; the anti-slip protrusions further enhance the friction between the sugarcane and the trough, reducing violent shaking caused by road bumps and preventing damage to the sugarcane stalk skin; when operating at night or in the early morning, the reflective marking 311 reflects the surrounding light to alert nearby workers or vehicles and reduce the risk of collision.

[0046] After transportation to the destination, the unloading mechanism at the bottom of the bucket is activated: the hydraulic push rod extends, driving the movable bottom plate to rotate around the hinge point at the rear end of the bucket (rotation angle 0-45°), using gravity to make the sugarcane slide down quickly and smoothly along the inclined movable bottom plate; compared with the traditional simple tipping bucket mechanism, the maximum rotation angle of 45° effectively avoids the problem of sugarcane getting stuck due to its long length and entanglement, eliminating the need for manual cleaning; after unloading is completed, the hydraulic push rod retracts, driving the movable bottom plate to reset, preparing for the next round of loading operations.

[0047] After a single transport operation is completed, loosen the quick-release connector 21 to separate the transport bucket from the tractor for easy storage or switching to other operating equipment; check the status of each mechanism, and if it is necessary to adjust the protection range or angle, repeat the above adjustment steps to adapt to the next sugarcane transport needs of different lengths or loads.

[0048] Finally, it should be noted that the electronic components in the drive screw 222 and other components in this embodiment are all general standard parts or components known to those skilled in the art. Their structure and principle can be learned by those skilled in the art through technical manuals or conventional experimental methods. In the idle part of this device, all the above-mentioned electrical components are connected by wires. The specific connection method should refer to the working order between each electrical component in the above working principle to complete the electrical connection. All of these are technologies known in the art.

[0049] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed utility model. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. A special transport container for sugarcane fields, characterized in that: The bucket body (1), tractor connecting assembly (2), and anti-detachment fixing mechanism (3) are included. The tractor connecting assembly (2) is located at the front end of the bucket body (1) and includes a quick-release connector (21) adapted to the rear suspension interface of the tractor and an angle adjustment mechanism (22). The anti-detachment fixing mechanism (3) includes a retractable guardrail (31) and an end limiting block (32) arranged along the two sides of the bucket body (1). The end limiting block (32) is located vertically inside the bucket body (1), and the upper end of the end limiting block (32) is connected and fixed to one end of the retractable guardrail (31).

2. The sugarcane field transport container according to claim 1, characterized in that: The trough (1) is an open trough adapted to the long strip structure of sugarcane. The length of the trough is 3-6m and the width is 1.2-1.8m. The inner wall of the trough is provided with anti-slip protrusions (11).

3. The sugarcane field transport container according to claim 1, characterized in that: The angle adjustment mechanism (22) can realize the pitch angle adjustment between the bucket (1) and the tractor from 0 to 15°. It includes a drive screw (221), a moving block (222), and a wedge block (223). The wedge block (223) is installed on the end of the bucket (1). The drive screw (221) drives the moving block (222) to move horizontally and cooperate with the lower inclined surface of the wedge block (223) to realize the angle adjustment of the bucket (1).

4. The sugarcane field transport container according to claim 1, characterized in that: The bottom of the bucket (1) is provided with a discharge mechanism, which includes a hydraulic push rod and a movable bottom plate. One end of the hydraulic push rod is hinged to the bottom of the bucket (1), and the other end is connected to the movable bottom plate. The movable bottom plate can be rotated around the rear hinge point of the bucket (1) with a rotation angle of 0-45°.

5. The sugarcane field transport hopper according to claim 2, characterized in that: The anti-slip protrusion (11) is a hemispherical structure with a diameter of 10-15mm. The distance between adjacent anti-slip protrusions (11) is 50-80mm. The anti-slip protrusion (11) is integrally formed with the bucket body (1).

6. The sugarcane field transport container according to claim 1, characterized in that: The retractable guardrail (31) is provided with reflective markings (311) on the outside.

7. The sugarcane field transport container according to claim 1, characterized in that: The retractable guardrail (31) includes several movable plates, and telescopic rods are slidably connected between the movable plates. The retractable guardrail (31) is extended and retracted by sliding the telescopic rods inside the movable plates, and is locked and fixed by locking bolts.

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