High-efficiency wood tray processing frame

Abstract

The utility model discloses a wood tray processing frame with high efficiency. The wood tray processing frame is provided with a placing end and a processing end, the wood tray processing frame comprises a main frame body; the circulating conveying device is provided with a circulating conveying path, and the circulating conveying path passes through the placing end and the machining end; the two placing frames are movably connected with the main frame body; and the circulating conveying device drives the two placing frames to circularly move along the circulating conveying path, so that the two placing frames alternately move to the placing end and the machining end respectively. According to the scheme, the two containing frames are arranged, in the nailing process, the two containing frames are located at the containing end and the machining end correspondingly, and when the mechanical arm conducts nailing operation on wood blocks and wood boards located at the machining end, a worker can place the wood blocks and the wood boards on the containing frames at the containing end, so that the steps of loading and nailing can be conducted at the same time. And compared with the scheme of adopting a single placing frame, the loading interval can be reduced, so that the tray processing speed can be effectively improved.

Description

Technical Field

[0001] This utility model relates to the field of pallet processing equipment technology, and in particular to a high-efficiency wooden pallet processing rack. Background Technology

[0002] In the existing technology, there are solutions that use robotic arms to nail wooden pallets. The robotic arms and the frames used to support and place the wooden pallets are generally set up in a work area that is enclosed by a fence.

[0003] Currently, this nailing solution is generally equipped with a wooden pallet processing frame, with a placement end and a processing end at each end. The wooden pallet processing frame has a placement rack, which moves back and forth between the placement end and the processing end via a drive structure. Workers place wooden boards and blocks at the placement end, while the nailing process is carried out at the processing end to avoid workers accidentally touching the robotic arm.

[0004] However, the aforementioned wooden pallet processing racks are generally equipped with only one placement rack, and the steps of nailing and placing wooden blocks and planks cannot be carried out simultaneously. The processing time required for a single pallet is relatively long, which is not conducive to the factory's rapid production. Utility Model Content

[0005] The technical problem to be solved by this utility model is to provide a highly efficient wooden pallet processing rack to solve one or more technical problems existing in the prior art, and at least provide a beneficial option or create conditions.

[0006] The solution to the technical problem of this utility model is:

[0007] A high-efficiency wooden pallet processing rack has mutually orthogonal first, second, and up / down directions;

[0008] The wooden pallet processing rack is provided with a placement end and a processing end, and the placement end and the processing end are arranged along a first direction;

[0009] The wooden pallet processing rack includes:

[0010] Main frame;

[0011] A circulating conveying device, wherein the circulating conveying device is provided with a circulating conveying path, the circulating conveying path passing through the placement end and the processing end;

[0012] The device includes two placement racks, which are movably connected to the main frame. The circulating conveying device drives the two placement racks to move cyclically along the circulating conveying path, so that the two placement racks alternately move to the placement end and the processing end, respectively.

[0013] As a further improvement to the above technical solution, the main frame is provided with a guide groove, the guide groove is provided with a guide path, and the guide path has the same shape and size as the cyclic conveying path;

[0014] The placement frame is equipped with guide wheels, which are disposed in the guide groove and are slidably connected to the guide groove.

[0015] As a further improvement to the above technical solution, the circulating conveying device includes:

[0016] Two main conveying devices are provided; the main conveying devices are arranged between the placement end and the processing end, and the two main conveying devices are arranged vertically; the main conveying devices drive the placement frame to move along a first direction, and the conveying directions of the two main conveying devices are opposite;

[0017] Two vertical conveying devices are provided, which are respectively located at the placement end and the processing end; each vertical conveying device has a vertical input end and a vertical output end, which are respectively connected to two main conveying devices; the vertical conveying devices drive the placement frame to move up and down and along a first direction.

[0018] As a further improvement to the above technical solution, the main conveying device includes:

[0019] Two main conveyor wheels are provided, and the two main conveyor wheels are arranged along a first direction. The main conveyor wheels are rotatably connected to the main frame.

[0020] A main drive unit is fixed to the main frame and connected to one of the main conveyor wheels, which drives the main conveyor wheel to rotate.

[0021] A main conveyor belt, which wraps around two main conveyor wheels and is connected to them in a driving manner;

[0022] The vertical conveying device includes:

[0023] Upper and lower drive components, which are fixed to the main frame;

[0024] The vertically movable frame is driven by the vertically moving drive component to move the vertically movable frame up and down.

[0025] Two secondary conveyor wheels are provided, and the secondary conveyor wheels are rotatably connected to the upper and lower movable frames.

[0026] A secondary drive unit is connected to one of the secondary conveyor wheels, and the secondary drive unit drives the secondary conveyor wheel to rotate.

[0027] The secondary conveyor belt passes around the two secondary conveyor wheels and is connected to the secondary conveyor wheels via a drive mechanism.

[0028] As a further improvement to the above technical solution, the upper and lower conveying device also includes a locking component;

[0029] The locking component includes:

[0030] A locking drive component, wherein the locking drive component is fixed to the upper and lower movable frame;

[0031] A locking component is fixed to the output end of the locking drive component, and the locking drive component drives the locking component to move up and down.

[0032] A locking slot is provided on the placement rack; the locking slot is used to insert and cooperate with the locking member to lock the placement rack.

[0033] As a further improvement to the above technical solution, it also includes: the placement frame is equipped with:

[0034] Multiple wooden board limiting posts are provided, and the multiple wooden board limiting posts are evenly arranged;

[0035] The wood block limiting groove is provided in multiple ways, and the multiple wood block limiting grooves are arranged in a matrix, with the groove openings of the wood block limiting grooves facing upwards.

[0036] As a further improvement to the above technical solution, the opening of the wooden block limiting groove is a trumpet shape that gradually narrows from top to bottom.

[0037] As a further improvement to the above technical solution, the wooden board limiting post includes a limiting sleeve and a limiting post body. The limiting sleeve is disposed above the limiting post body and is sleeved on the limiting post body. The limiting sleeve can move up and down relative to the limiting post body so that the length of the wooden board limiting post is adjustable.

[0038] As a further improvement to the above technical solution, the outer periphery of the limiting sleeve is a cylindrical surface, the limiting sleeve is provided with a first threaded structure, and the limiting column is provided with a second threaded structure. Both the first threaded structure and the second threaded structure extend in the vertical direction, and the first threaded structure and the second threaded structure are threadedly connected.

[0039] As a further improvement to the above technical solution, the outer circumferential surface of the limiting sleeve is provided with anti-slip texture.

[0040] The beneficial effects of this invention are as follows: This solution uses two placement racks, located at the placement end and processing end respectively during the nailing process. While the robotic arm nails the wood blocks and planks at the processing end, workers can place wood blocks and planks on the placement rack at the placement end, allowing the loading and nailing steps to be performed simultaneously. Compared to using a single placement rack, this reduces the loading interval, thereby effectively increasing the pallet processing speed.

[0041] This utility model relates to the field of pallet processing equipment technology. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this utility model, the accompanying drawings used in the description of the embodiments will be briefly explained below. Obviously, the described drawings are only a part of the embodiments of this utility model, and not all of them. Those skilled in the art can obtain other design schemes and drawings based on these drawings without creative effort.

[0043] Figure 1 This is a top view of an embodiment of the present invention.

[0044] Figure 2 This is a schematic diagram of the structure of the circulating conveying device, placement rack, etc., according to an embodiment of this utility model;

[0045] Figure 3 This is a schematic diagram of the structure of the placement rack, guide wheels, and guide groove of this utility model embodiment;

[0046] Figure 4 This is a cross-sectional structural schematic diagram of the placement rack according to an embodiment of the present utility model.

[0047] In the diagram, 100 is the main frame; 110 is the guide groove; 200 is the circulating conveyor; 210 is the main conveyor; 211 is the main conveyor wheel; 212 is the main drive component; 213 is the main conveyor belt; 220 is the upper and lower conveyor; 221 is the upper and lower drive component; 222 is the upper and lower moving frame; 223 is the secondary conveyor wheel; 224 is the secondary drive component; 225 is the secondary conveyor belt; 230 is the locking assembly; 231 is the locking drive component; 232 is the locking component; 233 is the locking groove; 300 is the placement frame; 310 is the wooden board limiting post; 311 is the limiting post body; 312 is the limiting sleeve; 320 is the wooden block limiting groove; and 330 is the guide wheel. Detailed Implementation

[0048] The following will clearly and completely describe the concept, specific structure, and technical effects of this utility model in conjunction with embodiments and accompanying drawings, so as to fully understand the purpose, features, and effects of this utility model. Obviously, the described embodiments are only a part of the embodiments of this utility model, not all of them. Other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are all within the scope of protection of this utility model. Furthermore, all connections / linkages mentioned herein do not simply refer to direct contact between components, but rather to the ability to form a better connection structure by adding or reducing connecting accessories according to specific implementation conditions. The various technical features in this invention can be combined interactively without contradicting each other.

[0049] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0050] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0051] In the existing technology, there are solutions that use robotic arms to nail wooden pallets. The robotic arms and the frames used to support and place the wooden pallets are generally set up in a work area that is enclosed by a fence.

[0052] Currently, this nailing solution is generally equipped with a wooden pallet processing frame, with a placement end and a processing end at each end. The wooden pallet processing frame has a placement rack, which moves back and forth between the placement end and the processing end via a drive structure. Workers place wooden boards and blocks at the placement end, while the nailing process is carried out at the processing end to avoid workers accidentally touching the robotic arm.

[0053] However, the aforementioned wooden pallet processing racks are generally equipped with only one placement rack, and the steps of nailing and placing wooden blocks and planks cannot be carried out simultaneously. The processing time required for a single pallet is relatively long, which is not conducive to the factory's rapid production.

[0054] To solve the above-mentioned technical problems, this solution is designed as a wooden pallet processing rack.

[0055] Reference Figures 1 to 4 The high-efficiency wooden pallet processing rack has a vertical direction, a second direction, and a first direction, with each of the three directions arranged orthogonally to the other.

[0056] The wooden pallet processing rack is equipped with a processing end and a placement end, which are arranged along a first direction.

[0057] Specifically, the wooden pallet processing rack includes: a main frame 100, a circulating conveyor 200, and a placement rack 300.

[0058] The main frame 100 is placed on the factory floor.

[0059] The circulating conveyor 200 is provided with a circulating conveying path that passes through the processing end and the placement end. Specifically, in this embodiment, the circulating conveying path is set as a rectangular path. In other embodiments, the circulating conveying path can also be set as a racetrack-shaped path. Those skilled in the art can select the specific shape of the circulating conveying path according to actual needs.

[0060] Specifically, in this embodiment, the circulating conveying device 200 includes: a main conveying device 210 and an upper and lower conveying device 220.

[0061] Specifically, the number of main conveying devices 210 is set to two. Both main conveying devices 210 are located between the processing end and the placement end. The two main conveying devices 210 are arranged in the vertical direction. The conveying directions of the two main conveying devices 210 are parallel to the first direction, and the conveying directions of the two main conveying devices 210 are opposite.

[0062] Specifically, the main conveying device 210 includes: a main conveying wheel 211, a main drive component 212, and a main conveyor belt 213.

[0063] The number of main conveyor wheels 211 is set to two, and the two main conveyor wheels 211 are arranged along the first direction. The main conveyor wheels 211 are rotatably connected to the main frame 100, and the main conveyor wheels 211 can rotate relative to the main frame 100 about an axis parallel to the second direction.

[0064] The main drive unit 212 is fixedly installed on the main frame 100. The main drive unit 212 is a rotary motor. The output end of the main drive unit 212 is fixedly connected to one of the main conveyor wheels 211 so that the main drive unit 212 can drive the main conveyor wheel 211 to rotate.

[0065] The main conveyor belt 213 passes around two main conveyor wheels 211, and the main conveyor belt 213 is connected to the main conveyor wheels 211 in a driving connection.

[0066] Specifically, in this embodiment, the inner side of the main conveyor belt 213 has a toothed structure, and the outer peripheral surface of the main conveyor wheel 211 also has a toothed structure. The toothed structures of the main conveyor belt 213 and the main conveyor wheel 211 mesh with each other, thereby preventing the main conveyor belt 213 and the main conveyor wheel 211 from slipping relative to each other due to slippage.

[0067] In other embodiments, the main conveyor belt 213 and the main conveyor wheel 211 may also be configured as a chain and sprocket structure. Those skilled in the art can choose a belt conveyor structure or a chain conveyor structure according to actual needs.

[0068] The upper and lower conveying device 220 includes: an upper and lower driving component 221, an upper and lower moving frame 222, a secondary conveying wheel 223, a secondary driving component 224, and a secondary conveyor belt 225.

[0069] The up-and-down drive component 221 is configured as an electric linear drive device. In other embodiments, the up-and-down drive component 221 may also be configured as a pneumatic or hydraulic linear drive device. Those skilled in the art can select the specific structure of the up-and-down drive component 221 according to actual needs. The up-and-down drive component 221 is fixedly installed on the main frame 100.

[0070] The vertical moving frame 222 is fixedly installed at the output end of the vertical driving component 221. When the vertical driving component 221 is working, it drives the vertical moving frame 222 to move in the vertical direction. Specifically, in this embodiment, a guide structure is provided between the vertical moving frame 222 and the main frame 100 to guide the vertical moving frame 222.

[0071] The number of secondary conveying wheels 223 is set to two, and the two secondary conveying wheels 223 are arranged along the first direction. The secondary conveying wheels 223 are rotatably connected to the upper and lower moving frame 222, and the secondary conveying wheels 223 can rotate relative to the upper and lower moving frame 222 about an axis parallel to the second direction.

[0072] The secondary drive component 224 is fixedly installed on the upper and lower movable frame 222. The secondary drive component 224 is a rotary motor. The output end of the secondary drive component 224 is fixedly connected to one of the secondary conveyor wheels 223. When the secondary drive component 224 is working, it drives the secondary conveyor wheel 223 to rotate.

[0073] The number of secondary conveyor belts 225 is set to multiple, and the multiple secondary conveyor belts 225 are arranged at intervals along the second direction. The multiple secondary conveyor belts 225 respectively pass around two secondary conveyor rollers 223, and the secondary conveyor belts 225 are connected to the secondary conveyor rollers 223 in a driving connection.

[0074] Specifically, in this embodiment, the inner side of the secondary conveyor belt 225 has a toothed structure, and the outer peripheral surface of the secondary conveyor wheel 223 also has a toothed structure. The toothed structures of the secondary conveyor belt 225 and the secondary conveyor wheel 223 mesh with each other, thereby preventing the secondary conveyor belt 225 and the secondary conveyor wheel 223 from slipping relative to each other due to slippage.

[0075] In other embodiments, the secondary conveyor belt 225 and the secondary conveyor wheel 223 may also be configured as a chain and sprocket structure. Those skilled in the art can choose a belt conveyor structure or a chain conveyor structure according to actual needs.

[0076] Specifically, in this embodiment, the upper and lower conveying device 220 also includes a locking component 230.

[0077] The locking assembly 230 includes a locking drive 231, a locking element 232, and a locking groove 233.

[0078] Specifically, in this embodiment, the locking drive 231 is configured as an electric linear drive device. In other embodiments, the locking drive 231 can also be configured as a pneumatic linear drive device or a hydraulic linear drive device. Those skilled in the art can select the driving method of the locking drive 231 according to actual needs.

[0079] The locking element 232 is fixedly installed at the output end of the locking drive element 231. When the locking drive element 231 is working, it drives the locking element 232 to move in the up and down direction. The locking element 232 is offset from the secondary conveyor belt 225 so that the locking element 232 can pass between two adjacent secondary conveyor belts 225.

[0080] The locking groove 233 is located at the lower end of the placement rack 300. When the placement rack 300 is located at the placement end or processing end, the locking drive 231 drives the locking member 232 to move upward, so that the locking member 232 is inserted into the locking groove 233, thereby locking the placement rack 300 to prevent the placement rack 300 from accidentally shifting when placing wooden boards or blocks or when nailing, thus ensuring the normal processing of the pallet and ensuring the processing quality of the pallet.

[0081] The number of placement racks 300 is set to two. The placement racks 300 are movably connected to the main frame 100. Both placement racks 300 are placed on the circulating conveyor 200. The circulating conveyor 200 conveys the placement racks 300, causing the placement racks 300 to move along the circulating conveyor path, so that the placement racks 300 go back and forth between the processing end and the placement end. The two placement racks 300 alternately move to the placement end and the processing end respectively.

[0082] This solution uses two placement racks 300. During the nailing process, the two racks 300 are located at the placement end and the processing end, respectively. While the robotic arm nails the wood blocks and planks at the processing end, workers can place wood blocks and planks on the placement racks 300 at the placement end, allowing the loading and nailing steps to be performed simultaneously. Compared to a solution using a single placement rack 300, this reduces the loading interval, thereby effectively increasing the pallet processing speed.

[0083] After nailing is completed, the rack 300 containing the finished product is conveyed to the placement end, and the rack 300 containing the wooden blocks and planks is conveyed to the processing end. The rack 300 moves back and forth between the processing end and the placement end.

[0084] Specifically, in this embodiment, the placement rack 300 is fixedly equipped with multiple wooden board limiting posts 310, arranged in a matrix. These posts limit the wooden boards, allowing them to be placed horizontally or vertically. The placement rack 300 also has multiple wooden block limiting slots 320, with the slot openings facing upwards. These slots are evenly arranged and are used to place wooden boards, thus limiting their placement.

[0085] Specifically, in this embodiment, the wooden board limiting post 310 includes a limiting post body 311 and a limiting sleeve 312. The limiting sleeve 312 is sleeved on the limiting post body 311, and the limiting post body 311 is located below the limiting sleeve 312. The vertical positions of the limiting post body 311 and the limiting sleeve 312 are adjustable, thereby making the overall length of the wooden board limiting post 310 adjustable. In other embodiments, the limiting sleeve 312 can also be located below the limiting post body 311. Those skilled in the art can select the specific positions of the limiting sleeve 312 and the limiting post 311 according to actual needs.

[0086] Specifically, in this embodiment, the outer circumferential surface of the limiting sleeve 312 is cylindrical, the inner circumferential surface of the limiting sleeve 312 is provided with a first threaded structure, and the outer circumferential surface of the limiting column 311 is provided with a second threaded structure. The second threaded structure is threadedly connected to the first threaded structure. By rotating the limiting sleeve 312, the limiting sleeve 312 can move up and down relative to the limiting column 311. Furthermore, through the self-locking function of the threaded structure, automatic locking between the limiting sleeve 312 and the limiting column 311 can be avoided, eliminating the need for additional locking structures and simplifying the overall structure.

[0087] Specifically, in this embodiment, the outer peripheral surface of the limiting sleeve 312 is provided with anti-slip texture. By providing anti-slip texture, it is possible to prevent the operator from slipping during the rotation of the limiting sleeve 312.

[0088] Specifically, in this embodiment, the opening of the wood block limiting groove 320 is a trumpet-shaped structure that gradually narrows from top to bottom, thereby guiding the wood block so that it can smoothly enter the wood block limiting groove 320.

[0089] Specifically, in this embodiment, the main frame 100 is provided with a guide groove 110, and the guide groove 110 is provided with a guide path. The guide path has the same shape and size as the cyclic conveying path.

[0090] The placement rack 300 is rotatably mounted with guide wheels 330, which are slidably connected to the guide groove 110.

[0091] By setting guide groove 110 and guide wheel 330, the placement rack 300 can be guided to avoid the placement rack 300 from deviating during the conveying process, thereby ensuring the normal operation of the wooden pallet processing rack.

[0092] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the embodiments described. Those skilled in the art can make various equivalent modifications or substitutions without departing from the spirit of the present invention. All such equivalent modifications or substitutions are included within the scope defined by the claims of this application.

Claims

1. A high-efficiency wooden pallet processing rack, characterized by: It has a first direction, a second direction, and a vertical direction that are mutually orthogonal; The wooden pallet processing rack is provided with a placement end and a processing end, and the placement end and the processing end are arranged along a first direction; The wooden pallet processing rack includes: Main frame; A circulating conveying device, wherein the circulating conveying device is provided with a circulating conveying path, the circulating conveying path passing through the placement end and the processing end; The device includes two placement racks, which are movably connected to the main frame. The circulating conveying device drives the two placement racks to move cyclically along the circulating conveying path, so that the two placement racks alternately move to the placement end and the processing end, respectively.

2. The high-efficiency wooden pallet processing rack according to claim 1, characterized in that: The main frame is provided with a guide groove, and the guide groove is provided with a guide path. The guide path has the same shape and size as the cyclic conveying path. The placement frame is equipped with guide wheels, which are disposed in the guide groove and are slidably connected to the guide groove.

3. The high-efficiency wooden pallet processing rack according to claim 1, characterized in that: The circulating conveying device includes: Two main conveying devices are provided; the main conveying devices are arranged between the placement end and the processing end, and the two main conveying devices are arranged vertically; the main conveying devices drive the placement frame to move along a first direction, and the conveying directions of the two main conveying devices are opposite; Two vertical conveying devices are provided, which are respectively located at the placement end and the processing end; each vertical conveying device has a vertical input end and a vertical output end, which are respectively connected to two main conveying devices; the vertical conveying devices drive the placement frame to move up and down and along a first direction.

4. The high-efficiency wooden pallet processing rack according to claim 3, characterized in that: The main conveying device includes: Two main conveyor wheels are provided, and the two main conveyor wheels are arranged along a first direction. The main conveyor wheels are rotatably connected to the main frame. A main drive unit, fixed to the main frame, connected to one of the main conveyor wheels, driving the main conveyor wheel to rotate; a main conveyor belt, passing over two of the main conveyor wheels, and connected to the main conveyor wheels in a transmission connection; The vertical conveying device includes: Upper and lower drive components, which are fixed to the main frame; The vertically movable frame is driven by the vertically moving drive component to move the vertically movable frame up and down. The system includes two secondary conveyor wheels, which are rotatably connected to the upper and lower movable frame; and a secondary drive unit, which is connected to one of the secondary conveyor wheels and drives the secondary conveyor wheel to rotate. The secondary conveyor belt passes around the two secondary conveyor wheels and is connected to the secondary conveyor wheels via a drive mechanism.

5. The high-efficiency wooden pallet processing rack according to claim 4, characterized in that: The upper and lower conveying device also includes a locking assembly; The locking component includes: A locking drive component, wherein the locking drive component is fixed to the upper and lower movable frame; A locking component is fixed to the output end of the locking drive component, and the locking drive component drives the locking component to move up and down. A locking slot is provided on the placement rack; the locking slot is used to insert and cooperate with the locking member to lock the placement rack.

6. The high-efficiency wooden pallet processing rack according to claim 1, characterized in that: Also includes: The placement rack is equipped with: Multiple wooden board limiting posts are provided, and the multiple wooden board limiting posts are evenly arranged; The wood block limiting groove is provided in multiple ways, and the multiple wood block limiting grooves are arranged in a matrix, with the groove openings of the wood block limiting grooves facing upwards.

7. The high-efficiency wooden pallet processing rack according to claim 6, characterized in that: The opening of the wooden block limiting groove is in the shape of a trumpet, gradually narrowing from top to bottom.

8. The high-efficiency wooden pallet processing rack according to claim 6, characterized in that: The wooden board limiting post includes a limiting sleeve and a limiting post body. The limiting sleeve is disposed above the limiting post body and is sleeved on the limiting post body. The limiting sleeve can move up and down relative to the limiting post body so that the length of the wooden board limiting post is adjustable.

9. The high-efficiency wooden pallet processing rack according to claim 8, characterized in that: The outer circumference of the limiting sleeve is cylindrical, the limiting sleeve is provided with a first threaded structure, and the limiting column is provided with a second threaded structure. Both the first threaded structure and the second threaded structure extend in the vertical direction, and the first threaded structure and the second threaded structure are threadedly connected.

10. The high-efficiency wooden pallet processing rack according to claim 8, characterized in that: The outer circumferential surface of the limiting sleeve is provided with anti-slip texture.

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