Automatic material feeding equipment of mining crusher
By combining the elastic connection between the sliding plate and the support plate with a tactile switch, the problem of uneven feeding in the crusher is solved, and automatic control of material height and environmental purification are achieved, thereby improving production efficiency and equipment safety.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANDONG XINGYE MASCH ACCESSORIES CO LTD
- Filing Date
- 2025-04-28
- Publication Date
- 2026-05-12
AI Technical Summary
The existing feeding method of crushers is inefficient, makes it difficult to ensure the uniformity and stability of feeding, and is prone to equipment failure. In addition, when there is too much material on the feeding belt, the material height cannot be adjusted in time, resulting in material waste and equipment damage.
The material leveling plate and support plate are connected by a spring, and the second material leveling plate is rotatably connected to the support base. It is equipped with a touch switch for detecting and adjusting the material height. Combined with the dust collection mechanism, the air is purified by a fan and a filter plate, so as to achieve automatic control of the material height and environmental cleanliness.
It effectively adjusts material height, avoids equipment failure, ensures uniform and stable feeding, reduces material waste, improves production efficiency, protects equipment, and keeps the working environment clean.
Smart Images

Figure CN224221522U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the technical field of mining feeding equipment, and in particular to an automatic material feeding device for mining crushers. Background Technology
[0002] In the mining and ore processing process, crushers are one of the important pieces of equipment used to crush large pieces of ore into suitable particle sizes. However, most of the existing crusher feeding methods have some problems. Traditional manual feeding methods are inefficient and it is difficult to ensure the uniformity and stability of the feeding. This can easily lead to crusher failure due to too much or too little feed, affecting production efficiency. Therefore, automatic material feeding equipment for mining crushers is needed.
[0003] A search revealed Chinese patent publication number CN205739529U, which discloses an automatic feeding device, including a machine body and a power supply device mounted on the machine body; a storage bin is located at the rear end of the machine body, and a hopper is located at the front end of the machine body; a base plate is also provided on the machine body, a feeding belt is mounted on the base plate, and an active roller for driving the feeding belt is located at the front end of the base plate, the active roller being positioned above the hopper; a steering roller is provided inside the storage bin, and the feeding belt is mounted on the active roller and the steering roller. The active roller is connected to the power supply device through a reduction gear assembly. The automatic feeding device provided by this utility model can place materials in the storage bin, and then the operating feeder belt will transport the materials to the hopper, thereby realizing fully automatic feeding, improving work efficiency, saving labor, reducing labor costs and work intensity. However, in actual use, when there are too many goods on the feeder belt, the height of the materials cannot be adjusted in time, exceeding the range of subsequent production processing. In addition, when too much material accumulates on the feeder belt, it will fall to both sides of the feeder belt, causing unnecessary material waste. Utility Model Content
[0004] To overcome the above shortcomings, this utility model provides an automatic material feeding device for mining crushers, which aims to improve the problem in the prior art that the height of the material cannot be adjusted in time when there is too much cargo on the feeding belt.
[0005] To achieve the above objectives, this utility model adopts the following technical solution: an automatic material feeding device for a mining crusher, including a base, a conveyor installed on the inner wall of the base, two guide rods fixed on the top left side of the base, the inner walls of the two guide rods slidably connected to the same support plate, an mounting plate fixedly connected to the bottom left side of the base, a push rod fixedly connected to the top of the mounting plate, the top of the push rod being fixedly connected to the support plate, a first smoothing plate rotatably connected to the rear side of the outer wall of the support plate, multiple springs fixedly connected to the bottom of the support plate, the rear ends of the multiple springs being fixedly connected to the first smoothing plate, a support seat fixedly connected to the top center of the base, a second smoothing plate rotatably connected to the right side of the outer wall of the support seat, an installation rod installed on the right side of the support seat, the bottom of the installation rod being fixedly connected to the base, a tactile switch fixedly connected to the bottom of the installation rod, and a dust collection mechanism installed on the top right side of the base for cleaning dust generated during the conveying process.
[0006] As a further description of the above technical solution:
[0007] The dust collection mechanism includes a dust collection box, which is fixedly connected to the top right side of the base. Multiple dust collection ports are provided on the left and right sides of the bottom of the dust collection box. A filter box is fixedly connected to the rear side of the outer wall of the base. A ventilation pipe is connected to the rear side of the outer wall of the dust collection box. The bottom end of the ventilation pipe is connected to the filter box. A filter plate is slidably connected to the inner wall of the filter box. The top of the filter plate passes through the filter box and is fixedly connected to a sealing gasket. The sealing gasket fits against the filter box. A fan is fixedly connected to the rear side of the outer wall of the filter box.
[0008] As a further description of the above technical solution:
[0009] A mounting box is fixedly connected to the top of the vacuum cleaner box, and an alarm light is fixedly connected to the inner wall of the mounting box.
[0010] As a further description of the above technical solution:
[0011] The base has multiple fixing feet on its bottom front and rear sides, and each fixing foot has two bolts threaded to its outer wall. All bolts are threaded to the base.
[0012] As a further description of the above technical solution:
[0013] A controller is fixedly connected to the left side of the front end of the outer wall of the base. The controller is electrically connected to the conveyor, the push rod and the tactile switch respectively.
[0014] As a further description of the above technical solution:
[0015] A warning sign is provided on the front side of the outer wall of the base. Multiple screws are threaded onto the outer wall of the warning sign, and the rear ends of the multiple screws are threaded onto the base.
[0016] As a further description of the above technical solution:
[0017] A handle is fixedly connected to the top of the filter plate, and the surface of the handle is treated with anti-slip material.
[0018] As a further description of the above technical solution:
[0019] Multiple anti-slip strips are fixedly connected to the ground surface of the conveyor, and the distance between adjacent anti-slip strips is equal.
[0020] This utility model has the following beneficial effects:
[0021] 1. In this utility model, the structure of the first smoothing plate and the support plate connected by springs, and the second smoothing plate rotatably connected to the support seat and cooperating with the tactile switch, effectively improves the problems of the prior art. When the material is conveyed, the first smoothing plate uses the anti-rotation force given by the spring to initially smooth the material to adapt to materials of different heights. The second smoothing plate further detects and adjusts the material height. If the material is too high, it will push the material to rotate and trigger the tactile switch, causing the conveyor to brake in an emergency, thus realizing the effective control of the material height.
[0022] 2. In this utility model, the fan starts to create negative pressure, which causes the dust generated by material conveying to be sucked in by the dust suction port at the bottom of the dust collection box. The dust-laden air flows into the filter box through the ventilation pipe. The filter plate is slidably connected to the inner wall of the filter box and intercepts the dust under the suction of the fan, thus purifying the air. When the filter plate is covered with dust and affects the efficiency, it can be easily lifted out for cleaning or replacement. This structure effectively solves the problem of dust generation during material conveying, ensures a clean working environment, and is simple to maintain, extending the service life of the equipment. Attached Figure Description
[0023] Figure 1 This is a perspective view of the automatic material feeding device for a mining crusher proposed in this utility model;
[0024] Figure 2 This is a partial structural schematic diagram of the automatic material feeding device for a mining crusher proposed in this utility model.
[0025] Figure 3 This is a schematic diagram of the push rod of the automatic material feeding device for a mining crusher proposed in this utility model;
[0026] Figure 4 This is a schematic diagram of the dust collection mechanism of the automatic material feeding device for a mining crusher proposed in this utility model;
[0027] Figure 5This is a schematic diagram of the dust inlet of the automatic material feeding device for a mining crusher proposed in this utility model.
[0028] Legend:
[0029] 1. Base; 2. Dust collection mechanism; 201. Dust collection box; 202. Dust collection port; 203. Filter box; 204. Ventilation pipe; 205. Filter plate; 206. Sealing gasket; 207. Fan; 3. Conveyor; 4. Guide rod; 5. Support plate; 6. Mounting plate; 7. Push rod; 8. Sliding plate one; 9. Spring; 10. Support base; 11. Sliding plate two; 12. Mounting rod; 13. Tactile switch; 14. Mounting box; 15. Alarm light; 16. Fixing foot; 17. Bolt; 18. Controller; 19. Warning sign; 20. Screw; 21. Handle; 22. Anti-slip strip. Detailed Implementation
[0030] 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.
[0031] Reference Figure 1 , Figure 2 and Figure 3This utility model provides an embodiment of an automatic material feeding device for a mining crusher, including a base 1, which serves as the basic support structure for the entire device and provides an installation and bearing platform for other components. A conveyor 3 is installed on the inner wall of the base 1 to drive materials forward along the inner wall of the base 1, achieving the material conveying function. Two guide rods 4 are fixed on the top left side of the base 1, providing a vertical sliding track for a support plate 5. The inner walls of the two guide rods 4 are slidably connected to the same support plate 5, which moves vertically under the guidance of the guide rods 4 to adjust the height of the connected sliding plate 8, accommodating materials of different heights. The bottom left side of the base 1... A mounting plate 6 is fixedly connected to the side for fixing the push rod 7 and providing an installation position for the push rod 7. The top of the mounting plate 6 is fixedly connected to the push rod 7, and the top of the push rod 7 is fixedly connected to the support plate 5. The push rod 7 pushes the support plate 5 up and down along the guide rod 4 through telescopic movement, thereby adjusting the height of the support plate 5 and the smoothing plate 8. The smoothing plate 8 is rotatably connected to the rear side of the outer wall of the support plate 5. The smoothing plate 8 can rotate around the connection point on the rear side of the outer wall of the support plate 5 to initially smooth the material passing through, so that the material remains relatively flat during the conveying process. Multiple springs 9 are fixedly connected to the bottom of the support plate 5. The springs 9 provide elastic support force for the smoothing plate 8, so that it faces the material. When handling materials of varying heights, the machine can both level the material and adaptively adjust itself through compression of springs 9 under the force of the material. The rear ends of multiple springs 9 are fixedly connected to the first leveling plate 8, ensuring that the elastic force of the springs 9 can accurately act on the first leveling plate 8, realizing the buffering and adaptive functions of the first leveling plate 8. A support base 10 is fixedly connected to the top center of the machine base 1 for mounting the second leveling plate 11, allowing it to rotate around the right side of the outer wall of the support base 10 for further detection and adjustment of the material height. The second leveling plate 11 is rotatably connected to the right side of the outer wall of the support base 10, and can rotate around the connection point on the right side of the support base 10. When the material height is too high, the second leveling plate is pushed. The rotation of the second platen 11 triggers the subsequent emergency braking mechanism. A mounting rod 12 is provided on the right side of the support base 10. The mounting rod 12 is used to fix the tactile switch 13. The bottom of the mounting rod 12 is fixedly connected to the base 1 to ensure the stability of the mounting rod 12, thereby ensuring the normal operation of the tactile switch 13. The bottom of the mounting rod 12 is fixedly connected to the tactile switch 13. The tactile switch 13 is used to detect the rotation of the second platen 11. When the second platen 11 rotates to a certain extent and touches the tactile switch 13, the emergency braking mechanism is triggered, causing the conveyor 3 to stop running. A dust collection mechanism 2 is provided on the top right side of the base 1. The dust collection mechanism 2 is used to clean the dust generated during the conveying process.
[0032] Specifically, two guide rods 4 fixed on the top left side of the base 1 provide a vertical sliding track for the support plate 5. Push rods 7 on the mounting plate 6 can push the support plate 5 up and down along the guide rods 4, thereby adjusting the height of the support plate 5 and the connected smoothing plate 8 to accommodate materials of different heights. The smoothing plate 8, rotatably connected to the rear side of the outer wall of the support plate 5, is connected to the bottom of the support plate 5 by multiple springs 9. When materials pass over the smoothing plate 8, the springs 9 provide strong anti-rotation force, so even if the material height is uneven, the smoothing plate 8 can initially smooth the material under the buffering effect of the springs 9. If the material is too high, the smoothing plate 8 will compress the springs 9 and move upwards under the push of the material, still able to smooth the material to a certain extent. The material is initially leveled to ensure it continues to be conveyed in a relatively flat state. After initial leveling, the material reaches the second leveling plate 11, which is rotatably connected to the right side of the outer wall of the support base 10 at the top center of the machine base 1. The second leveling plate 11 can rotate around the right side of the support base 10. Its function is to further detect the material height. When the material height exceeds the set range, the material pushes the second leveling plate 11 to rotate. The tactile switch 13 installed at the bottom of the mounting rod 12 on the right side of the support base 10 will immediately trigger the emergency braking mechanism once it is touched by the rotating second leveling plate 11. The tactile switch 13 transmits a signal to the control system of the conveyor 3, causing the conveyor 3 to stop operating. At the same time, it reminds the staff that the material height does not meet the requirements and needs to be handled to avoid damage to the crusher caused by excessively high material.
[0033] Reference Figure 4 and Figure 5 The dust collection mechanism 2 includes a dust collection box 201, which is fixedly connected to the top right side of the base 1. The dust collection box 201 is used to contain dust-laden air drawn in from the material conveying area. Multiple suction ports 202 are provided on the left and right sides of the bottom of the dust collection box 201 to draw dust generated during material conveying into the dust collection box 201 under negative pressure. A filter box 203 is fixedly connected to the rear side of the outer wall of the base 1 to filter the dust-laden air drawn in by the dust collection box 201, separating dust from air. A ventilation pipe 204 connects the rear side of the outer wall of the dust collection box 201 to the filter box 203. The function is to ensure that dust-laden air can flow smoothly from the dust collection box 201 to the filter box 203. The bottom end of the ventilation pipe 204 is connected to the filter box 203. The inner wall of the filter box 203 is slidably connected to the filter plate 205, which is used to intercept dust in the dust-laden air and allow purified air to pass through. The top of the filter plate 205 penetrates the filter box 203 and is fixedly connected to the sealing gasket 206. The sealing gasket 206 fits against the filter box 203 to prevent unfiltered dust-laden air from leaking from the gap between the filter plate 205 and the filter box 203, thus ensuring the filtration effect. The rear side of the outer wall of the filter box 203 is fixedly connected to the fan 207.
[0034] Specifically, the dust collection mechanism 2 operates synchronously during equipment operation. The dust collection box 201 of the dust collection mechanism 2 is fixed on the top right side of the base 1, and multiple dust collection ports 202 on the left and right sides of its bottom are close to the material conveying area. The dust collection box 201 is connected to the filter box 203 on the rear side of the outer wall of the base 1 through the ventilation pipe 204. The fan 207 is fixed on the rear side of the outer wall of the filter box 203. After starting, a negative pressure is formed inside the dust collection mechanism 2. Under the action of negative pressure, the dust generated during the material conveying process is sucked into the dust collection box 201 from the dust collection port 202, and then enters the filter box 203 through the ventilation pipe 204. The filter plate 205 slidably connected inside the filter box 203 filters the dust-laden air. The dust is intercepted on the filter plate 205, and the purified air is discharged. The sealing gasket 206 on the top of the filter plate 205 is in contact with the filter box 203 to prevent unfiltered air from leaking. When a lot of dust accumulates on the filter plate 205 and affects the filtration effect, the filter plate 205 can be cleaned or replaced by pulling it upward.
[0035] Reference Figure 1 , Figure 2 and Figure 3 The top of the dust collection box 201 is fixedly connected to the mounting box 14, and the inner wall of the mounting box 14 is fixedly connected to the alarm light 15. When the dust collection mechanism 2 is blocked or malfunctions, the alarm light 15 will light up to remind the staff to repair it. The bottom of the base 1 is provided with multiple fixed feet 16 on the front and rear sides. The outer wall of each fixed foot 16 is threaded with two bolts 17. The bolts 17 are threaded to the base 1. The fixed feet 16 are fastened to the ground or mounting surface by the bolts 17 threaded to them to ensure stable operation of the equipment. The left side of the front end of the outer wall of the base 1 is fixedly connected to the controller 18. The controller 18 is electrically connected to the conveyor 3, the push rod 7 and the tactile switch 13 respectively. The controller 18 receives the signal from the tactile switch 13 to control the start and stop of the conveyor 3. It can also adjust the push rod 7 to adjust the height of the support plate 5 as needed to ensure smooth material conveying.
[0036] Specifically, the alarm light 15 inside the mounting box 14 at the top of the dust collection box 201 illuminates when the dust collection mechanism 2 is blocked or malfunctions, reminding staff to perform maintenance. The fixed feet 16 at the bottom of the base 1 are secured to the ground or mounting surface by bolts 17 threaded to them, ensuring stable operation of the equipment. The controller 18 on the left side of the front end of the base 1 receives the signal from the touch switch 13 and controls the start and stop of the conveyor 3; it can also adjust the push rod 7 to adjust the height of the support plate 5 as needed, ensuring smooth material conveying.
[0037] Reference Figure 1 , Figure 2 and Figure 4A warning sign 19 is installed on the front side of the outer wall of the base 1, which indicates the precautions for equipment operation and safety warnings, reminding operators to operate in accordance with regulations and avoid safety accidents caused by misoperation. Multiple screws 20 are threadedly connected to the outer wall of the warning sign 19, and the rear ends of the multiple screws 20 are threaded to the base 1. A handle 21 is fixedly connected to the top of the filter plate 205, which makes it easier for staff to hold and pull out the filter plate 205 more securely when cleaning or replacing it, preventing inconvenience or damage to the filter plate 205 due to slipping. The surface of the handle 21 is treated with anti-slip treatment. Multiple anti-slip strips 22 are fixedly connected to the surface of the conveyor 3. The distance between adjacent anti-slip strips 22 is equal, which increases the friction between the material and the surface of the conveyor 3, preventing the material from slipping due to shaking or tilting during the conveying process, and ensuring that the material is transported to the designated position smoothly and safely.
[0038] Specifically, the warning sign 19 is fixed by multiple screws 20 that are threaded to the base 1. The warning sign 19 is marked with equipment operation precautions and safety warnings to remind operators to operate in accordance with regulations, avoid safety accidents caused by misoperation, and ensure the safety of personnel and equipment. The handle 21 allows the staff to hold and pull out the filter plate 205 more securely when cleaning or replacing it, preventing inconvenience or damage to the filter plate 205 due to slipping. The anti-slip strip 22 increases the friction between the material and the surface of the conveyor 3, preventing the material from slipping due to shaking or tilting during the conveying process, and ensuring that the material is transported smoothly and safely to the designated position.
[0039] Working principle: When the equipment starts, the conveyor 3 begins to operate, driving the material forward along the inner wall of the base 1. The material first passes through the smoothing plate 8 on the rear side of the outer wall of the support plate 5. Since the smoothing plate 8 is connected to the support plate 5 by multiple springs 9, it gives the smoothing plate 8 strong anti-rotation force. When the material passes through, it can initially smooth the material. Even if the material is higher than expected, under the pushing force of the material, the smoothing plate 8 will move slightly under the buffer of the springs 9, but it can still straighten the material to a certain extent, keeping the material in a relatively flat state for continued conveying. The material that has been initially smoothed will then reach the smoothing plate 11 on the right side of the outer wall of the support base 10. At this location, the second smoothing plate 11 can rotate around the right side of the support base 10. It plays a role in further detecting and adjusting the material height. If the material height is still too high after the initial smoothing, when the material passes the second smoothing plate 11, the material will push the second smoothing plate 11 to rotate. When the second smoothing plate 11 rotates to a certain extent, it will touch the light touch switch 13 fixedly connected to the bottom of the mounting rod 12. Once the light touch switch 13 is triggered, the emergency braking mechanism will be activated, causing the running conveyor 3 to stop immediately. This design is to prevent excessively high materials from damaging the subsequent crushing equipment, and at the same time remind the on-site personnel that the material height does not meet the requirements and needs to be smoothed in time.
[0040] Furthermore, after the fan 207 starts, it generates a strong suction, creating a negative pressure environment inside the dust collection mechanism 2. Multiple suction ports 202 on the left and right sides of the bottom of the dust collection box 201 are close to the material conveying area. Under the action of negative pressure, the dust generated during the material conveying process is sucked into the dust collection box 201. The dust-laden air sucked into the dust collection box 201 enters the filter box 203 through the ventilation pipe 204. The ventilation pipe 204 connects the dust collection box 201 and the filter box 203, ensuring that the dust-laden air can flow smoothly. The dust-laden air is pushed by the suction of the fan 207 through the filter plate 205. The dust is intercepted by the filter plate 205, and the purified air continues to flow through the filter plate 205. As the filtration process continues, dust will gradually accumulate on the filter plate 205, affecting the filtration efficiency. Since the filter plate 205 is slidably connected to the inner wall of the filter box 203, when it is necessary to clean the filter plate 205, it can be removed from the filter box 203 by lifting the filter plate 205 upwards for cleaning or replacement. The operation is convenient and quick.
[0041] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. An automatic material feeding device for a mining crusher, comprising a base (1), characterized in that: The inner wall of the base (1) is provided with a conveyor (3). Two guide rods (4) are fixed to the top left of the base (1). The inner walls of the two guide rods (4) are slidably connected to the same support plate (5). A mounting plate (6) is fixedly connected to the bottom left of the base (1). A push rod (7) is fixedly connected to the top of the mounting plate (6). The top of the push rod (7) is fixedly connected to the support plate (5). A smoothing plate (8) is rotatably connected to the rear side of the outer wall of the support plate (5). Multiple springs (9) are fixedly connected to the bottom of the support plate (5). The rear end of the spring (9) is fixedly connected to the first squeegee (8). A support seat (10) is fixedly connected to the top center of the base (1). A second squeegee (11) is rotatably connected to the right side of the outer wall of the support seat (10). An installation rod (12) is provided on the right side of the support seat (10). The bottom of the installation rod (12) is fixedly connected to the base (1). A tactile switch (13) is fixedly connected to the bottom of the installation rod (12). A dust collection mechanism (2) is provided on the top right side of the base (1). The dust collection mechanism (2) is used to clean the dust generated during the conveying process.
2. The automatic material feeding equipment for a mining crusher according to claim 1, characterized in that: The dust collection mechanism (2) includes a dust collection box (201), which is fixedly connected to the top right side of the base (1). Multiple dust collection ports (202) are provided on the bottom left and right sides of the dust collection box (201). A filter box (203) is fixedly connected to the rear side of the outer wall of the base (1). A ventilation pipe (204) is connected to the rear side of the outer wall of the dust collection box (201). The bottom end of the ventilation pipe (204) is connected to the filter box (203). A filter plate (205) is slidably connected to the inner wall of the filter box (203). The top of the filter plate (205) passes through the filter box (203) and is fixedly connected to a sealing gasket (206). The sealing gasket (206) fits against the filter box (203). A fan (207) is fixedly connected to the rear side of the outer wall of the filter box (203).
3. The automatic material feeding equipment for a mining crusher according to claim 2, characterized in that: The top of the vacuum box (201) is fixedly connected to a mounting box (14), and an alarm light (15) is fixedly connected to the inner wall of the mounting box (14).
4. The automatic material feeding equipment for a mining crusher according to claim 1, characterized in that: The base (1) is provided with multiple fixing feet (16) on the front and rear sides of the bottom. The outer walls of the multiple fixing feet (16) are threaded with two bolts (17), and the multiple bolts (17) are threaded to the base (1).
5. The automatic material feeding equipment for a mining crusher according to claim 1, characterized in that: A controller (18) is fixedly connected to the left side of the front end of the outer wall of the base (1). The controller (18) is electrically connected to the conveyor (3), the push rod (7) and the tactile switch (13).
6. The automatic material feeding equipment for a mining crusher according to claim 1, characterized in that: A warning sign (19) is provided on the front side of the outer wall of the base (1). Multiple screws (20) are threadedly connected to the outer wall of the warning sign (19). The rear ends of the multiple screws (20) are threadedly connected to the base (1).
7. The automatic material feeding equipment for a mining crusher according to claim 2, characterized in that: The top of the filter plate (205) is fixedly connected to a handle (21), and the surface of the handle (21) is treated with anti-slip treatment.
8. The automatic material feeding equipment for a mining crusher according to claim 1, characterized in that: The surface of the conveyor (3) is fixedly connected with a plurality of anti-slip strips (22), and the distance between adjacent anti-slip strips (22) is equal.