A lifting accessory for a crane

Abstract

The present invention relates to the technical field of lifting accessories, and specifically to a lifting accessory for a crane, comprising two groups of plate limiting components, a lifting rod, a limiting rod group and a lifting rope; each group of the plate limiting components comprises two horizontal shafts distributed up and down, and two groups of left and right circulating transmission mechanisms connected to the horizontal shafts, and the circulating transmission mechanisms comprise an upper wheel structure, a lower wheel structure, a belt structure and a plurality of limiting structures. The lifting accessory proposed in the present application is aimed at the lifting of plates, and the plate limiting component in the accessory is provided with a plurality of limiting grooves at different heights, and the limiting grooves can be moved to different heights. When loading plates, the plate limiting component moves downward from above the stacked plates, and fixes the plates to the limiting grooves layer by layer, so as to realize the lifting of large-capacity plates, and when unloading plates, the target number of plates can be unloaded in batches to different regions according to needs.

Description

Technical Field

[0001] The invention relates to the technical field of lifting accessories, and in particular to a lifting accessory for a crane. Background Art

[0002] In construction or cargo yard lifting, stacks of plate materials need to be lifted in many occasions, such as prefabricated metal plates, wooden plates, concrete plates, etc. The traditional lifting method is generally to bundle multiple plates and then lift them together. This lifting method is labor-intensive and has safety hazards.

[0003] At present, suction cups or clamping mechanisms are usually used to lift plates. For example, a plate lifting device proposed in Publication No. CN117682433A uses a vacuum pump to draw negative pressure from the suction cup to lift the plate, but can only lift a single plate. Another example is a plate clamp proposed in Publication No. CN106494996A, which uses a suction cup in combination with a clamping claw, but can still only clamp and lift a limited number of plates. Therefore, there is no effective lifting accessory to facilitate lifting equipment for lifting plates. Summary of the invention

[0004] The present invention provides a lifting accessory for a crane, comprising two sets of plate limiting components, a lifting rod, a limiting rod set and a lifting rope;

[0005] Each group of the plate limiting components includes two horizontal shafts distributed up and down, and two groups of left and right circulating transmission mechanisms connected to the horizontal shafts. The circulating transmission mechanism includes an upper wheel structure, a lower wheel structure, a belt structure, and a plurality of limiting structures. The upper wheel structure and the lower wheel structure are respectively connected to the two horizontal shafts. The belt structure is connected to the upper wheel structure and the lower wheel structure. A plurality of limiting structures are connected to the surface of the belt structure at equal intervals, and a limiting groove is formed between two upper and lower adjacent limiting structures.

[0006] The lifting rod is connected to both ends of each set of plate limiting components, the horizontal shaft can rotate relative to the lifting rod, and the lifting rod is configured to control the rotation state of the horizontal shaft;

[0007] The limiting rod group is connected to the lifting rod at the same end of the two sets of plate limiting components, and the lifting rope is connected to the lifting rod;

[0008] Among them, the four limiting grooves on the same horizontal plane in the two groups of plate limiting components constitute a limiting space, and a plurality of limiting spaces distributed along the vertical direction are formed between the two groups of plate limiting components. The limiting space is set to change its height position when the horizontal axis rotates, and maintain this height position when the horizontal axis stops rotating.

[0009] Preferably, two limit boxes are provided on the lifting rod, and the axial end of the horizontal axis extends into the limit box. A hanging rod is provided inside the lifting rod, and the hanging rod can move along the length direction inside the lifting rod. The hanging rod includes a first position and a second position. When the hanging rod is pulled upward, it moves from the first position to the second position. When the hanging rod is in the first position, the horizontal axis can rotate freely relative to the limit box. When the hanging rod is in the second position, the horizontal axis is locked and cannot be transmitted relative to the limit box. The lifting rope is connected to the top of the hanging rod.

[0010] Preferably, the suspension rod completely penetrates the lifting rod from the upper end of the lifting rod and extends to the bottom end of the lifting rod, and the bottom of the suspension rod is lower than the lowest point of the circulating transmission mechanism.

[0011] Preferably, the suspension rod is provided with a waist-shaped hole, the waist-shaped hole is in the limit box, and the shaft end of the horizontal axis is provided with a gear, the gear is in the waist-shaped hole, and a tooth plate is provided at the bottom of the waist-shaped hole. When the suspension rod is in the second position, the gear contacts the tooth plate, and the horizontal axis is restricted from rotating. When the suspension rod is in the first position, the gear is disengaged from the tooth plate, and the horizontal axis rotates freely.

[0012] Preferably, a retaining ring is further provided on the outer wall of the suspension rod, and the retaining ring is arranged in the limit box. A spring is further provided between the retaining ring and the limit box, and the spring has a tendency to move the suspension rod from the second position to the first position.

[0013] Preferably, the upper wheel structure or the lower wheel structure includes an inner wheel and outer wheels arranged on both sides of the inner wheel, a first belt structure is arranged outside the inner wheel, and a second belt structure is arranged outside the outer wheel, the diameter of the outer wheel is larger than the diameter of the inner wheel, and the limiting structure includes a limiting rod, which is connected to the first belt structure and the second belt structure, and the limiting rod extends beyond the second belt structure to support the plate.

[0014] Preferably, the limiting rod includes an inner rod and a sleeve rod, the inner rod is connected to the first belt structure and the second belt structure, the sleeve rod can slide on the outer wall of the inner rod, and an elastic member is provided between the inner rod and the sleeve rod so that the sleeve rod tends to move away from the inner rod.

[0015] Preferably, an elastic layer is provided on the surface of the sleeve rod, and an end of the elastic layer is configured as a hemispherical arc surface.

[0016] Preferably, the limiting rod group includes a cross rod group, and both ends of the cross rod group are detachably connected to the lifting rod.

[0017] Preferably, a lifting ring is provided at the top end of the lifting rod, and the lifting rope is connected to the lifting ring.

[0018] Compared with the prior art, the advantages of the present invention are:

[0019] The lifting accessories proposed in the present application are aimed at lifting plates. The plate limiting components in the accessories are provided with a plurality of limiting grooves at different heights, and the limiting grooves can be moved to different heights. When loading plates, the plate limiting components move downward from above the stacked plates, and fix the plates to the limiting grooves layer by layer, so that large-capacity plate lifting can be achieved. Moreover, when unloading plates, the target number of plates can be unloaded in batches to different regions according to needs. It can be seen that this lifting accessory for plates has a greater loading capacity and unloading flexibility in plate lifting. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in various figures may be represented by the same reference numeral. For clarity, not every component is labeled in every figure. Embodiments of various aspects of the present invention will now be described by way of example and with reference to the accompanying drawings, in which:

[0021] Figure 1 It is a schematic diagram of the structure of the lifting accessories for cranes shown in the invention;

[0022] Figure 2 It is a schematic diagram of two sets of plate limiting components shown in the present invention limiting a plurality of equally spaced plates;

[0023] Figure 3 It is a structural schematic diagram of the upper wheel structure, the limit box and the limit structure shown in the present invention;

[0024] Figure 4 It is a schematic diagram of two sets of plate limiting components shown in the present invention limiting plates with unequal spacing;

[0025] Figure 5 is a schematic diagram of the lifting accessory shown in the present invention loading a plate at position A;

[0026] Figure 6 It is a schematic diagram of the lifting accessories shown in the present invention for lifting a plate;

[0027] Figure 7 is a schematic diagram of the lifting accessory shown in the present invention unloading part of the plate at position B;

[0028] Figure 8 It is a schematic diagram of the lifting accessory shown in the present invention unloading another part of the plate at C.

[0029] Reference numerals:

[0030] 10. Horizontal shaft; 20. Circular transmission mechanism; 30. Lifting rod; 40. Limiting rod group; 50. Lifting rope;

[0031] 101, second set of plate limiting components; 102, first set of plate limiting components; 201, upper wheel structure; 202, lower wheel structure;

[0032] 11. Gear;

[0033] 21. Inner wheel; 22. Outer wheel; 23. First belt structure; 24. Second belt structure; 25. Limiting structure;

[0034] 251, inner rod; 252, sleeve rod; 253, elastic layer; 254, elastic member;

[0035] 32. Suspension rod; 321. Waist-shaped hole; 322. Tooth plate; 323. Retaining ring; 33. Limit box; 331. Spring. DETAILED DESCRIPTION

[0036] In order to better understand the technical content of the present invention, specific embodiments are given and described as follows in conjunction with the accompanying drawings.

[0037] Combination Figure 1 As shown, the present invention proposes a lifting accessory for a crane, including two groups of plate limiting components, a lifting rod 30, a limiting rod group 40 and a lifting rope 50; the two groups of plate limiting components are arranged on both sides, and the middle area is used to accommodate multiple plates, the lifting rod 30 and the limiting rod group 40 are used to support the two groups of plate limiting components to form a stable cubic frame, and the lifting rope 50 is used to establish a connection between the constructed cubic frame and the hook.

[0038] Optionally, the lifting rope 50 is a steel wire rope, and the limiting rod group 40 includes a cross rod group. Both ends of the cross rod group are detachably connected to the lifting rod 30. The cross rod group mainly serves to limit the front and rear sides of the plate and support the two groups of plate limiting components.

[0039] like Figure 1-2 As shown, each group of plate limiting components includes two horizontal shafts 10 distributed up and down, and two left and right groups of circulating transmission mechanisms 20 connected to the horizontal shafts 10. The circulating transmission mechanism 20 includes an upper wheel structure 201, a lower wheel structure 202, a belt structure and a plurality of limiting structures 25. The upper wheel structure 201 and the lower wheel structure 202 are respectively connected to the two horizontal shafts 10, the belt structure is connected to the upper wheel structure 201 and the lower wheel structure 202, and a plurality of limiting structures 25 are connected to the surface of the belt structure at equal intervals, and a limiting groove is formed between two adjacent limiting structures 25 above and below.

[0040] It can be seen that the multiple limiting structures 25 can be constrained within the closed-loop trajectory through the upper wheel structure 201, the lower wheel structure 202 and the belt structure, and the formed closed-loop trajectory includes two vertical trajectories, wherein, in the two vertical trajectories, the first side of the plate limiting component (the side close to another group of plate limiting components) is the effective limiting side, on which the multiple limiting structures 25 can move along the vertical trajectory, that is, the multiple limiting grooves formed can change their height position.

[0041] Furthermore, four limiting grooves on the same horizontal plane in two groups of plate limiting components (the first group of plate limiting components 102 on the left and the second group of plate limiting components 101 on the right as shown in the figure) (each group of plate limiting components includes only two limiting grooves at the same horizontal position) constitute a limiting space, and a plurality of limiting spaces distributed along the vertical direction are formed between the two groups of plate limiting components. The limiting space is configured to change its height position when the horizontal shaft 10 rotates, and maintain the height position when the horizontal shaft 10 stops rotating.

[0042] In this way, when the horizontal shaft 10 rotates, the two sets of plate limiting components can load or unload the plates, and when the horizontal shaft 10 stops rotating, the plates can be lifted and transferred.

[0043] In an optional embodiment, when a stack of plates needs to be lifted, the two sets of plate limiting components can be controlled to reach above the plates. It should be understood that the spacing between the two sets of plate limiting components is slightly larger than the width or length of the plates, and the plates are also spaced by pads to form a predetermined thickness of spacing between the plates, so that the limiting structure 25 can be inserted to support the plates at the current height layer. Figure 5 As shown, when the two sets of plate limiting components are lifted downward, the horizontal shaft 10 is controlled to rotate freely, and the belt structures of the two sets of plate limiting components rotate, so that the limiting structures 25 on the surface of the belt structure are inserted into the gaps between the plates, until the belt structure completely covers a stack of plates, that is, the limiting structure 25 extends under the bottom plate, and then the plate at position A can be lifted upward; Figure 6 As shown, during lifting, the horizontal shaft 10 is controlled to remain fixed so that the plate limiting component can keep limiting all plates, such as Figure 7 As shown, as needed, part of the accommodated plates can be placed at B, and the remaining plates can continue to be transferred, such as Figure 8 As shown, transfer the remaining plates to C.

[0044] In this way, a large-capacity plate accommodating area can be formed by two sets of plate limiting components, especially more than ten plates of the same size can be accommodated at one time, and the number of plates unloaded after lifting can be controlled, and the loaded plates can be unloaded at different locations.

[0045] Furthermore, the lifting rod 30 is connected to both ends of each group of plate limiting components, the horizontal axis 10 can rotate relative to the lifting rod 30, and the lifting rod 30 is configured to control the rotation state of the horizontal axis 10, the limiting rod group 40 is connected to the lifting rod 30 at the same end of the two groups of plate limiting components, and the lifting rope 50 is connected to the lifting rod 30.

[0046] In this way, the lifting rod 30 can provide support for the plate limiting component and also serve as a load-bearing structure for lifting. By controlling the rotation state of the horizontal axis 10 through the lifting rod 30, the load-bearing state of the plate limiting component can be controlled.

[0047] Furthermore, in order to facilitate the control of the rotation state of the horizontal shaft 10, Figure 3 As shown, two limit boxes 33 are provided on the lifting rod 30, and the axial end of the horizontal shaft 10 extends into the limit box 33. A suspension rod 32 is provided inside the lifting rod 30, and the suspension rod 32 can move along the length direction inside the lifting rod 30.

[0048] Among them, the suspension rod 32 includes a first position and a second position. When the suspension rod 32 is pulled upward, it moves from the first position to the second position. When the suspension rod 32 is in the first position, the horizontal axis 10 can rotate freely relative to the limit box 33. When the suspension rod 32 is in the second position, the horizontal axis 10 is locked and cannot be transmitted relative to the limit box 33. The lifting rope 50 is connected to the top of the suspension rod 32.

[0049] In this way, when the suspension rod 32 is pulled upward, the horizontal axis 10 is locked and cannot rotate. At this time, the multiple limiting structures 25 remain in a fixed position. Therefore, the limiting space for the plate formed by each limiting structure 25 is stable. In this state, the plate can be lifted and transferred. When the suspension rod 32 is not pulled upward, the horizontal axis 10 can rotate freely. Therefore, at this time, the multiple limiting structures 25 can change their height positions. In this state, the loading and unloading of the plate can be completed.

[0050] In an optional embodiment, the suspension rod 32 is provided with a waist-shaped hole 321, the waist-shaped hole 321 is in the limit box 33, and the shaft end of the horizontal axis 10 is provided with a gear 11, the gear 11 is in the waist-shaped hole 321, and a tooth plate 322 is provided at the bottom of the waist-shaped hole 321. When the suspension rod 32 is in the second position, the gear 11 contacts the tooth plate 322, and the horizontal axis 10 is restricted from rotating. When the suspension rod 32 is in the first position, the gear 11 is out of contact with the tooth plate 322, and the horizontal axis 10 rotates freely.

[0051] In this way, when the boom 32 is in the first position, the gear 11 is not in contact with the tooth plate 322, and the horizontal axis 10 is not constrained and can rotate freely. When the boom 32 is in the second position, the gear 11 and the tooth plate 322 are in contact, and the horizontal axis 10 is limited by the tooth plate 322 and cannot rotate, so the horizontal axis 10 is locked.

[0052] In an optional embodiment, a lifting ring is provided at the top of the lifting rod 32, and the lifting rope 50 is connected to the lifting ring.

[0053] In this way, during the lifting process, the lifting rope 50 tightens the lifting rod 32, and the lifting rod 32 moves upward from the first position to the second position, so that the gear 11 and the tooth plate 322 fit together, and there is a large pressure between the gear 11 and the tooth plate 322, and it will not loosen.

[0054] In an optional embodiment, a retaining ring 323 is further provided on the outer wall of the suspension rod 32. The retaining ring 323 is arranged in the limit box 33. A spring 331 is further provided between the retaining ring 323 and the limit box 33. The spring 331 has a tendency to move the suspension rod 32 from the second position to the first position.

[0055] In this way, the elastic force of the spring 331 can push the suspension rod 32 in the non-suspended state from the second position to the first position, so that the horizontal shaft member 10 can rotate freely.

[0056] Furthermore, the suspension rod 32 completely penetrates the lifting rod 30 from the upper end of the lifting rod 30 and extends to the bottom end of the lifting rod 30, and the bottom of the suspension rod 32 is lower than the lowest point of the circulating transmission mechanism 20. In this way, when the accessory is placed on the ground, the suspension rod 32 touches the ground, and the suspension rod 32 moves from the first position to the second position, maintaining the stability of the plate limiting component and protecting the limiting structure 25 from touching the ground and being damaged.

[0057] In a specific loading process, please refer to Figure 5 As shown, taking multiple plates placed on the supporting platform at equal intervals as an example, the accessories are lifted and transferred to the top of the plates. At this time, the suspension rod 32 is in the second position, that is, the horizontal axis 10 cannot rotate freely, and the accessories are gradually lowered. When the limiting structure 25 at the lowest point of the plate limiting component contacts the top plate, the plate supports the accessories. At this time, the suspension rod 32 is transferred from the second position to the first position, and the horizontal axis 10 can rotate freely. The belt structure in the left plate limiting component rotates counterclockwise, and the belt structure in the right plate limiting component rotates clockwise to control the lowering speed. The accessories move downward as a whole, and each limiting structure 25 is stuck under the corresponding plate until the bottom of the suspension rod 32 contacts the ground. The suspension rod 32 is transferred from the first position to the second position again to complete the loading process, and the loaded accessories and plates can be lifted.

[0058] For a specific uninstallation process, please refer to Figure 7 As shown, after the accessories are above the loading platform B, the accessories are gradually lowered. When the bottom plate contacts the loading platform B, the loading platform supports the plate. At this time, the suspension rod 32 is transferred from the second position to the first position, and the horizontal shaft 10 can rotate freely. At this time, the worker controls the lifting rod 30, and the lifting rope 50 pulls the lifting rod 32 upward, keeping the speed of the lifting rope 50 moving upward lower than or the same as the speed of the lifting rod 30 moving upward (at this time, the weight of the lifting rod 30 lifted by the worker is only the weight of the accessories, which is different from the weight of the lifted plate). The lifting rod 30 stops moving upward, but the lifting rope 50 still pulls the lifting rod 32 upward, so the lifting rod 32 moves upward relative to the lifting rod 30, and the lifting rod 32 moves from the first position to the second position, and the horizontal shaft 10 cannot rotate freely, and enters the lifting state.

[0059] In an optional embodiment, the upper wheel structure 201 or the lower wheel structure 202 includes an inner wheel 21 and outer wheels 22 arranged on both sides of the inner wheel 21, a first belt structure 23 is arranged outside the inner wheel 21, and a second belt structure 24 is arranged outside the outer wheel 22, the diameter of the outer wheel 22 is greater than the diameter of the inner wheel 21, and the limiting structure 25 includes a limiting rod, which is connected to the first belt structure 23 and the second belt structure 24, and the limiting rod extends beyond the second belt structure 24 to support the plate.

[0060] In this way, by setting the inner wheel 21 and the outer wheel 22, two support points can be formed for the limit rod, that is, the connection with the first belt structure 23 is the first support point, and the connection with the second belt structure 24 is the second support point. Through the two support points, the limit rod can be stably supported and its posture can be kept stable.

[0061] Optionally, the upper wheel structure 201 or the lower wheel structure 202 uses a sprocket, and the belt structure uses a transmission chain or a steel belt to ensure the strength of the structure.

[0062] Furthermore, the limiting rod includes an inner rod 251 and a sleeve rod 252. The inner rod 251 is connected to the first belt structure 23 and the second belt structure 24. The sleeve rod 252 can slide on the outer wall of the inner rod 251. An elastic member 254 is provided between the inner rod 251 and the sleeve rod 252, so that the sleeve rod 252 tends to move away from the inner rod 251.

[0063] Among them, the inner rod 251 is a hollow tube, the sleeve rod 252 is a hollow tube, and a core column is provided inside the hollow tube. The core column can be inserted into the inner wall of the inner rod 251, and the inner wall of the sleeve rod 252 fits with the outer wall of the inner rod 251.

[0064] In this way, the limiting rods form a retractable structure, and even if the spacing between the plates is different, the limiting rods at different positions can support the plates of corresponding heights.

[0065] like Figure 4 As shown, when the plates are arranged into multiple groups, each group includes multiple plates close to each other, the stacked plates can be regarded as several plates with different thicknesses. It should be understood that, unlike the loading and unloading of the above-mentioned single plates separated from each other, each group of plates should be unloaded in the same area. When loading, if there is no gap at the current height corresponding to the limit rod, it is compressed to the retracted position. When there is a gap at the current height corresponding to the limit rod, it extends into the gap to support the plate above the gap. When unloading, a group of plates close to each other are unloaded in the same area at one time.

[0066] In a preferred embodiment, the surface of the sleeve rod 252 is provided with an elastic layer 253, and the end of the elastic layer 253 is set to a hemispherical arc surface. The optional elastic layer 253 is nylon or rubber packaging material, which can increase the protection of the plate and facilitate the limit rod to extend into the gap between the plates.

[0067] In combination with the above embodiments, the lifting accessories proposed in the present application are aimed at the lifting of plates. The plate limiting components in the accessories are provided with multiple limiting grooves at different heights, and the limiting grooves can be moved to different heights. When loading plates, the plate limiting components move downward from the top of the stacked plates, and fix the plates to the limiting grooves layer by layer, so as to realize large-capacity plate lifting. Moreover, when unloading plates, the target number of plates can be unloaded in batches to different regions as needed. It can be seen that this lifting accessory for plates has greater loading capacity and unloading flexibility in plate lifting.

[0068] Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. A person with ordinary knowledge in the technical field to which the present invention belongs may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention shall be determined by the definition of the claims.

Claims

1. A lifting accessory for a crane, characterized in that: It comprises two sets of plate limiting components, a lifting rod (30), a limiting rod set (40) and a lifting rope (50); Each group of the plate limiting components comprises two horizontal shafts (10) distributed in an upper and lower manner, and two groups of left and right circulating transmission mechanisms (20) connected to the horizontal shafts (10); the circulating transmission mechanism (20) comprises an upper wheel structure (201), a lower wheel structure (202), a belt structure, and a plurality of limiting structures (25); the upper wheel structure (201) and the lower wheel structure (202) are respectively connected to the two horizontal shafts (10); the belt structure is connected to the upper wheel structure (201) and the lower wheel structure (202); a plurality of limiting structures (25) are connected to the surface of the belt structure at equal intervals, and a limiting groove is formed between two upper and lower adjacent limiting structures (25); The lifting rod (30) is connected to both ends of each set of plate limiting components, the horizontal shaft (10) can rotate relative to the lifting rod (30), and the lifting rod (30) is configured to control the rotation state of the horizontal shaft (10); The limiting rod group (40) is connected to the lifting rod (30) at the same end of the two sets of plate limiting components, and the lifting rope (50) is connected to the lifting rod (30); The four limiting grooves on the same horizontal plane in the two groups of plate limiting components constitute a limiting space, and a plurality of limiting spaces distributed in the vertical direction are formed between the two groups of plate limiting components. The limiting space is configured to change its height position when the horizontal shaft (10) rotates, and to remain at the height position when the horizontal shaft (10) stops rotating; The hoisting rod (30) is provided with two limit boxes (33), the shaft end of the horizontal shaft member (10) extends into the limit box (33), the hoisting rod (30) is provided with a suspension rod (32), the suspension rod (32) can move along the length direction in the hoisting rod (30), the suspension rod (32) includes a first position and a second position, when the suspension rod (32) is pulled upward, it moves from the first position to the second position, when the suspension rod (32) is in the first position, the horizontal shaft member (10) can rotate freely relative to the limit box (33), when the suspension rod (32) is in the second position, the horizontal shaft member (10) is locked and cannot be transmitted relative to the limit box (33), the hoisting rope (50) is connected to the top of the suspension rod (32); The suspension rod (32) completely penetrates the lifting rod (30) from the upper end of the lifting rod (30) and extends to the bottom end of the lifting rod (30), and the bottom of the suspension rod (32) is lower than the lowest point of the circulating transmission mechanism (20); The suspension rod (32) is provided with a waist-shaped hole (321), the waist-shaped hole (321) is in the limit box (33), and the shaft end of the horizontal shaft member (10) is provided with a gear (11), the gear (11) is in the waist-shaped hole (321), and a toothed plate (322) is provided at the bottom of the waist-shaped hole (321); when the suspension rod (32) is in the second position, the gear (11) contacts the toothed plate (322), and the horizontal shaft member (10) is restricted from rotating; when the suspension rod (32) is in the first position, the gear (11) is out of contact with the toothed plate (322), and the horizontal shaft member (10) is free to rotate; The outer wall of the suspension rod (32) is further provided with a retaining ring (323), the retaining ring (323) being arranged in the limit box (33), and a spring (331) is further provided between the retaining ring (323) and the limit box (33), the spring (331) having a tendency to move the suspension rod (32) from the second position to the first position.

2. A lifting accessory for a crane according to claim 1, characterized in that: The upper wheel structure (201) or the lower wheel structure (202) comprises an inner wheel (21) and outer wheels (22) arranged on both sides of the inner wheel (21); a first belt structure (23) is arranged outside the inner wheel (21); a second belt structure (24) is arranged outside the outer wheel (22); the diameter of the outer wheel (22) is greater than the diameter of the inner wheel (21); the limiting structure comprises a limiting rod, the limiting rod is connected to the first belt structure (23) and the second belt structure (24); the limiting rod extends beyond the second belt structure (24) to support the plate.

3. A lifting accessory for a crane according to claim 2, characterized in that: The limiting rod comprises an inner rod (251) and a sleeve rod (252); the inner rod (251) is connected to the first belt structure (23) and the second belt structure (24); the sleeve rod (252) can slide on the outer wall of the inner rod (251); an elastic member (254) is provided between the inner rod (251) and the sleeve rod (252), so that the sleeve rod (252) tends to move away from the inner rod (251).

4. A lifting accessory for a crane according to claim 3, characterized in that: An elastic layer (253) is provided on the surface of the sleeve rod (252), and an end of the elastic layer (253) is configured as a hemispherical arc surface.

5. A lifting accessory for a crane according to claim 1, characterized in that: The limiting rod group (40) comprises a cross rod group, and both ends of the cross rod group are detachably connected to the lifting rod (30).

6. A lifting accessory for a crane according to claim 1, characterized in that: A lifting ring is provided at the top end of the lifting rod (32), and the lifting rope (50) is connected to the lifting ring.

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