Architectural decoration arc-shaped wall surface polishing equipment

Abstract

The invention discloses building decoration arc-shaped wall surface polishing equipment, and relates to the field of building decoration, and the technical scheme is that the building decoration arc-shaped wall surface polishing equipment comprises a rack, a grip convenient for a user to hold is fixedly arranged on the rack, and a polishing mechanism for polishing a wall surface is rotatably arranged in the middle of the rack; the two sides of the rack are each provided with a limiting mechanism in a rotating mode, the limiting mechanisms are used for limiting the rack so that it can be guaranteed that the axis of the grinding roller is parallel to the wall face all the time, the two limiting mechanisms are linked through a radian adjusting mechanism, and the radian adjusting mechanism synchronously drives the limiting mechanisms on the two sides to conduct symmetrical angle deflection around the rotating axes of the limiting mechanisms. And the limiting mechanism and the polishing roller are adjusted to adapt to the curvature of the arc-shaped wall surface. The polishing device has the beneficial effects that through the limiting mechanism and the radian adjusting mechanism, the posture of the rack is matched with the radian of the wall face, and the surface of the polishing roller is attached to the wall face; and the equipment can be flexibly converted between concave / convex arc-shaped wall surfaces, so that the process application range is expanded.

Description

Technical Field

[0001] The present invention relates to the field of architectural decoration, and particularly to a grinding device for an arc-shaped wall surface in architectural decoration. Background Art

[0002] In architectural decoration projects, the surface treatment of interior walls is a key process to ensure the adhesion of coatings and the decorative effect. The traditional construction process includes, in sequence, the application of a curing layer, the scraping of a putty layer, and the construction of a primer layer and a topcoat layer. Before applying the curing layer, it is necessary to pre-treat the concrete base surface, with a focus on removing protruding cement blocks and grinding it to a flat surface.

[0003] When the mainstream wall grinding devices on the current market grind an arc-shaped wall surface, they cannot be in close contact with the arc-shaped wall surface. Summary of the Invention

[0004] In view of the above technical problems, the present invention provides a grinding device for an arc-shaped wall surface in architectural decoration.

[0005] The technical solution is as follows: It includes a frame, on which a handle convenient for the user to hold is fixedly arranged. In the middle of the frame, a grinding mechanism for wall grinding is rotatably arranged. The grinding mechanism includes a grinding roller rotatably arranged on the frame and a grinding motor for driving the grinding roller to work. On both sides of the frame, a set of limiting mechanisms are respectively rotatably arranged. The limiting mechanisms are used to limit the frame to ensure that the axis of the grinding roller is always parallel to the wall surface. The two sets of limiting mechanisms are linked by a curvature adjustment mechanism. The curvature adjustment mechanism synchronously drives the limiting mechanisms on both sides to make symmetric angular deflections around their rotation axes, adjusting the limiting mechanisms and the grinding roller to adapt to the curvature of the arc-shaped wall surface.

[0006] Preferably, each set of limiting mechanisms includes a rotating shaft rotatably arranged on the frame. At both ends of the rotating shaft, an outer rod is respectively fixedly arranged. An inner rod is sleeved in the outer rod. The movable ends of the two inner rods are connected by a mounting seat, and the mounting seat is respectively rotatably connected to the two inner rods. At both ends of the mounting seat, a roller is respectively rotatably arranged.

[0007] Preferably, two limiting grooves are opened on the outer wall of each inner rod. A fixed ring is fixedly arranged on the outer rod. Two limiting pins are rotatably arranged in the fixed ring. The two limiting pins are symmetrically arranged. A torsion spring is arranged on the fixed ring in the middle of the two limiting pins, and the torsion spring abuts against the limiting pins. A through groove is also opened on the side wall of the outer rod. The movable end of the limiting pin penetrates through the through groove and abuts against one of the limiting grooves.

[0008] Preferably, an adjusting rod is slidably arranged on the inner wall of the inner rod. The adjusting rod is rotatably connected to the outer rod. One end of the adjusting rod is fixedly provided with a driven bevel gear. One driving bevel gear is meshed with one side of each driven bevel gear. The two driving bevel gears are fixedly connected by a fixing rod. One output bevel gear is fixedly arranged in the middle of each fixing rod. The output bevel gear is meshed with an input bevel gear. The input bevel gear is rotatably connected to the frame. The two input bevel gears are fixedly connected by a connecting rod.

[0009] Preferably, a driven bevel gear is fixedly arranged in the middle of the connecting rod. A control wheel is arranged on the frame. A plug rod is fixedly arranged on the control wheel. The plug rod is slidably connected to the frame. A driving bevel gear is fixedly arranged at the movable end of the plug rod. A spring is sleeved outside the plug rod. Two ends of the spring respectively abut against the frame and the control wheel. When the control wheel is pressed, the spring is compressed, and the driving bevel gear is meshed with the driven bevel gear.

[0010] Preferably, the radian adjusting mechanism includes chutes opened on both sides of the frame. Two sliders are slidably arranged in each chute. One connecting rod is rotatably arranged on each slider. The movable end of the connecting rod is rotatably connected to an adjacent outer rod.

[0011] Preferably, a bidirectional lead screw is rotatably arranged in the chute. The two sliders located in the same chute are respectively threadedly connected to one end of the bidirectional lead screw. A worm gear is fixedly arranged in the middle of the bidirectional lead screw. One worm is rotatably arranged on each side of the frame. The worm is meshed with an adjacent worm gear. The two worms are fixedly connected by a transmission rod. A hand wheel is fixedly arranged on one worm. The hand wheel is coaxially fixed to the transmission rod.

[0012] Preferably, the grinding roller is in a cylindrical shape. One end of the grinding roller is fixedly provided with a driven sprocket. A grinding motor is fixedly arranged on the frame. A driven sprocket is coaxially fixedly arranged on the motor shaft of the grinding motor. The driving sprocket is connected to the driven sprocket by a chain. A plurality of convex platforms are arranged on the side wall of the grinding roller. Each convex platform is spirally arranged on the outer surface of the grinding roller.

[0013] The beneficial effects brought by the technical solution provided by the embodiment of the present invention are as follows: through the limiting mechanism and the radian adjusting mechanism, the posture of the frame is matched with the radian of the wall surface, so that the surface of the grinding roller is attached to the wall surface; the equipment can be flexibly switched between concave / convex arc-shaped wall surfaces, expanding the applicable range of the process. Brief Description of the Drawings

[0014] Figure 1 Schematic diagram of the overall structure of the embodiment of the present invention Figure 1 。

[0015] Figure 2 is Figure 1 front view of

[0016] Figure 3 Schematic diagram of the overall structure of the embodiment of the present invention Figure 2 front view of

[0017] Figure 4 Schematic diagram of the limiting mechanism and the arc adjusting mechanism of the embodiment of the present invention

[0018] Figure 5 Partial schematic diagram of the limiting mechanism of the embodiment of the present invention

[0019] Figure 6 Cross-sectional view of the inner rod and the fixing ring of the embodiment of the present invention

[0020] Figure 7 Schematic diagram of the control wheel and the driven bevel gear of the embodiment of the present invention

[0021] Figure 8 Schematic diagram of the grinding mechanism of the embodiment of the present invention

[0022] Among them, the reference numerals are: 1, frame; 2, grip; 3, grinding mechanism; 4, grinding roller; 5, grinding motor; 6, limiting mechanism; 7, arc adjusting mechanism; 8, rotating shaft; 9, outer rod; 10, inner rod; 11, mounting seat; 12, roller; 13, limiting groove; 14, fixing ring; 15, limiting pin; 16, torsion spring; 17, adjusting rod; 18, driven bevel gear; 19, driving bevel gear; 20, fixing rod; 21, output bevel gear; 22, input bevel gear; 23, connecting rod; 24, driven bevel gear; 25, control wheel; 26, driving bevel gear; 27, spring; 28, slider; 29, connecting rod; 30, bidirectional lead screw; 31, worm gear; 32, worm; 33, transmission rod; 34, hand wheel; 35, driven sprocket; 36, driving sprocket; 37, chain. Detailed Description of the Preferred Embodiments

[0023] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Of course, the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0024] It should be noted that, without conflict, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0025] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation to the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first", "second", etc. may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise stated, the meaning of "a plurality" is two or more.

[0026] In the description of the present invention, it should be noted that unless otherwise clearly defined and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific circumstances.

[0027] Embodiment 1 See Figures 1 to 8 , the present invention provides a grinding device for an arc-shaped wall surface of building decoration, including a frame 1, on which a handle 2 convenient for the user to hold is fixedly arranged. A grinding mechanism 3 for wall surface grinding is rotatably arranged in the middle of the frame 1. The grinding mechanism 3 includes a grinding roller 4 rotatably arranged on the frame 1 and a grinding motor 5 for driving the grinding roller 4 to work; A set of limiting mechanisms 6 are respectively rotatably arranged on both sides of the frame 1. The limiting mechanisms 6 are used to limit the frame 1 to ensure that the axis of the grinding roller 4 is always parallel to the wall surface. The two sets of limiting mechanisms 6 are linked by a curvature adjusting mechanism 7. The curvature adjusting mechanism 7 synchronously drives the limiting mechanisms 6 on both sides to make symmetric angular deflections around their rotation axes, and adjusts the limiting mechanisms 6 and the grinding roller 4 to adapt to the curvature of the arc-shaped wall surface.

[0028] Place the device in front of the arc-shaped wall surface to be ground, and make the limiting mechanisms 6 on both sides contact the wall surface; operate the curvature adjusting mechanism 7 to drive the two sets of limiting mechanisms 6 to deflect synchronously, so that the attitude of the frame 1 matches the curvature of the wall surface, and make the surface of the grinding roller 4 adhere to the wall surface. Start the grinding motor 5 to drive the grinding roller 4 to rotate, and the user moves the frame 1 along the wall surface for grinding operations.

[0029] Each set of limit mechanisms 6 includes a rotating shaft 8 rotatably arranged on the frame 1. At both ends of the rotating shaft 8, an outer rod 9 is fixedly arranged respectively. An inner rod 10 is sleeved inside the outer rod 9. The movable ends of the two inner rods are connected through a mounting seat 11, and the mounting seat 11 is rotatably connected to the two inner rods 10 respectively; At both ends of the mounting seat 11, a roller 12 is rotatably arranged respectively.

[0030] According to the wall curvature requirement, rotate the outer rods 9 of the limit mechanisms 6 on both sides synchronously, so that the axis of the roller 12 is far from or close to the axis of the grinding roller 4, making the grinding roller 4 adhere to the wall. By changing the axis of the roller 12 and the axis of the grinding roller 4, it can adapt to arc-shaped walls with different curvatures. The user moves the frame 1 along the wall for grinding operations.

[0031] Two limit grooves 13 are opened on the outer wall of each inner rod 10; A fixing ring 14 is fixedly arranged on the outer rod 9. Two limit pins 15 are rotatably arranged inside the fixing ring 14. The two limit pins 15 are symmetrically arranged. A torsion spring 16 is arranged on the fixing ring 14 in the middle of the two limit pins 15, and the torsion spring 16 abuts against the limit pins 15; A through groove is also opened on the side wall of the outer rod 9. The movable end of the limit pin 15 penetrates through the through groove and abuts against one of the limit grooves 13.

[0032] When the limit pin 15 is stuck into one of the limit grooves 13 close to the mounting seat 11, at this time, the inner rod 10 is completely received into the outer rod 9, and the axis of the roller 12 is shorter from the axis of the rotating shaft 8, adapting to the concave arc-shaped wall; When the limit pin 15 is stuck into the other limit groove 13, the inner rod 10 extends outwards, and the axis of the roller 12 is longer from the axis of the rotating shaft 8, adapting to the convex arc-shaped wall.

[0033] An adjusting rod 17 is slidably arranged on the inner wall of the inner rod 10. The adjusting rod 17 is rotatably connected to the outer rod 9. A driven bevel gear 18 is fixedly arranged at one end of the adjusting rod 17. One side of each driven bevel gear 18 meshes with a driving bevel gear 19, and the two driving bevel gears 19 are fixedly connected through a fixing rod 20; An output bevel gear 21 is fixedly arranged in the middle of each fixing rod 20. One side of the output bevel gear 21 meshes with an input bevel gear 22, and the input bevel gear 22 is rotatably connected to the frame 1; The two input bevel gears 22 are fixedly connected through a connecting rod 23.

[0034] When it is necessary to switch the state of the inner rod 10, rotate the connecting rod 23 to drive the input bevel gear 22 to rotate. The input bevel gear 22 drives the fixing rod 20 to rotate synchronously through the output bevel gear 21, so that the driving bevel gears 19 on both sides mesh with the driven bevel gears 18; The driven bevel gear 18 drives the adjusting rod 17 to rotate, causing the inner rod 10 to rotate about its own axis. When the inner rod 10 rotates, the limit pin 15 disengages from the original limit groove 13, and the operator lifts the frame 1 to enable the inner rod 10 to axially slide under the action of gravity; After the inner rod 10 moves to the target position, rotate the connecting rod 23 in the reverse direction to make the inner rod 10 rotate back. The limit pin 15 automatically snaps into another limit groove 13 under the action of the torsion spring 16 to complete the locking.

[0035] Through the transmission design of the connecting rod 23 and the bevel gear set, the synchronous control of the two-side limit mechanisms 6 is realized, greatly improving the adjustment efficiency.

[0036] A driven bevel gear 24 is fixedly arranged in the middle of the connecting rod 23; A control wheel 25 is arranged on the frame 1. A plug rod is fixedly arranged on the control wheel 25. The plug rod is slidably connected with the frame 1. The movable end of the plug rod is fixedly provided with a driving bevel gear 26. A spring 27 is sleeved outside the plug rod. The two ends of the spring 27 respectively abut against the frame 1 and the control wheel 25; When the control wheel 25 is pressed, the spring 27 is compressed, and the driving bevel gear 26 meshes with the driven bevel gear 24.

[0037] When the state of the inner rod 10 needs to be adjusted, press the control wheel 25 to move towards the frame 1 against the resistance of the spring 27. The driving bevel gear 26 axially displaces with the plug rod to mesh with the driven bevel gear 24. Keep pressing and rotate the control wheel 25. The driving bevel gear 26 drives the driven bevel gear 24 to rotate, driving the connecting rod 23 to rotate synchronously; The connecting rod 23 drives the two-side limit mechanisms 6 to act synchronously. The inner rod 10 rotates to release the locking of the limit pin 15. After the adjustment is completed, release the control wheel 25, and the spring 27 resets to automatically disengage the driving bevel gear 26 from the driven bevel gear 24.

[0038] During the adjustment of the inclination angle of the outer rod 9, the two driving bevel gears 19 and the fixed rod 20 will rotate as the outer rod 9 rotates, further driving the rotation of the input bevel gear 22 and the connecting rod 23. The transmission coupling and separation are realized through the pressing-rotation composite action to maintain the stability of the adjustment system. The radian adjustment mechanism 7 includes chutes opened on both sides of the frame 1. Two sliders 28 are slidably arranged in each chute. A connecting rod 29 is rotatably arranged on each slider 28. The movable end of the connecting rod 29 is rotatably connected to an adjacent outer rod 9.

[0039] According to the wall radian requirement, synchronously push the sliders 28 in the chutes on both sides of the frame 1 to axially slide along the chutes. When the sliders 28 move, the corresponding outer rods 9 are pulled by the connecting rods 29 to rotate around their rotating shafts 8, changing the relative angle between the outer rods 9 and the frame 1; The symmetric deflection drive roller 12 mounting seats 11 on both sides of the outer rod 9 form a support angle adapted to the curvature of the wall surface; the linkage design of the double slider 28 and the connecting rod 29 in the chute ensures the synchronous and equal deflection of the outer rods 9 on both sides; the connecting rod 29 can support the outer rod 9 and improve the structural strength of the outer rod 9.

[0040] A bidirectional lead screw 30 is rotatably arranged in the chute, and the two sliders 28 located in the same chute are respectively threadedly connected to one end of the bidirectional lead screw 30; A worm gear 31 is fixedly arranged in the middle of the bidirectional lead screw 30, a worm 32 is rotatably arranged on both sides of the frame 1 respectively, the worm 32 is engaged with an adjacent worm gear 31, the two worms 32 are fixedly connected by a transmission rod 33, and a hand wheel 34 is fixedly arranged on one of the worms 32, and the hand wheel 34 is coaxially fixed with the transmission rod 33.

[0041] Rotating the hand wheel 34 drives the worm 32 to rotate, and drives the bidirectional lead screw 30 to rotate synchronously through the engagement of the worm gear 31. The reverse threads at both ends of the bidirectional lead screw 30 drive the two sliders 28 in the same chute to slide towards or away from each other; When the slider 28 moves, it pulls the outer rod 9 to deflect around the rotating shaft 8 through the connecting rod 29, synchronously adjusts the support angles of the rollers 12 on both sides, and the self-locking characteristics of the worm gear 31 and the worm 32 automatically maintain the position of the slider 28 and maintain the stability of the state of the outer rod 9 after adjustment. Push the frame 1 along the wall surface for grinding operation.

[0042] The grinding roller 4 is in a cylindrical shape, a driven sprocket 35 is fixedly arranged at one end of the grinding roller 4, a grinding motor 5 is fixedly arranged on the frame 1, a driven sprocket 35 is coaxially fixedly arranged on the motor shaft of the grinding motor 5, and the driving sprocket 36 is connected with the driven sprocket 35 through a chain 37; A plurality of convex platforms are arranged on the side wall of the grinding roller 4, and each convex platform is arranged in a spiral shape on the outer surface of the grinding roller 4.

[0043] Starting the grinding motor 5 drives the driving sprocket 36 to rotate, and drives the driven sprocket 35 and the grinding roller 4 to rotate synchronously through the chain 37 transmission; The spiral convex platform forms an axial cutting track as the grinding roller 4 rotates and contacts the arc-shaped wall surface for grinding.

[0044] When the present invention is in use, the device is placed in front of the arc-shaped wall surface to be ground, so that the two limiting mechanisms 6 on both sides are in contact with the wall surface; operate the arc adjustment mechanism 7 to drive the two groups of limiting mechanisms 6 to deflect synchronously, so that the posture of the frame 1 matches the arc of the wall surface, make the surface of the grinding roller 4 adhere to the wall surface, start the grinding motor 5 to drive the grinding roller 4 to rotate, and the user moves the frame 1 along the wall surface for grinding operation.

[0045] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A grinding device for an arc-shaped wall surface of building decoration, characterized in that, It includes a frame (1), on which a grip (2) convenient for the user to hold is fixedly arranged. A grinding mechanism (3) for wall grinding is rotatably arranged in the middle of the frame (1). The grinding mechanism (3) includes a grinding roller (4) rotatably arranged on the frame (1) and a grinding motor (5) for driving the grinding roller (4) to work; A set of limiting mechanisms (6) are respectively rotatably arranged on both sides of the frame (1). The limiting mechanisms (6) are used to limit the frame (1) to ensure that the axis of the grinding roller (4) is always parallel to the wall surface. The two sets of limiting mechanisms (6) are linked by a radian adjusting mechanism (7). The radian adjusting mechanism (7) synchronously drives the limiting mechanisms (6) on both sides to make symmetric angular deflections around their rotation axes, and adjusts the limiting mechanisms (6) and the grinding roller (4) to adapt to the curvature of the arc-shaped wall.

2. The architectural decoration arc-shaped wall surface grinding device according to claim 1, wherein Each set of limiting mechanisms (6) includes a rotating shaft (8) rotatably arranged on the frame (1). Outer rods (9) are respectively fixedly arranged at both ends of the rotating shaft (8). Inner rods (10) are sleeved in the outer rods (9). The movable ends of the two inner rods are connected by a mounting seat (11). The mounting seat (11) is respectively rotatably connected to the two inner rods (10); Rollers (12) are respectively rotatably arranged at both ends of the mounting seat (11).

3. The abrasive device for the arc-shaped wall surface of building decoration according to claim 2, characterized in that, Two limiting grooves (13) are respectively opened on the outer wall of each inner rod (10); A fixed ring (14) is fixedly arranged on the outer rod (9). Two limiting pins (15) are rotatably arranged in the fixed ring (14). The two limiting pins (15) are symmetrically arranged. A torsion spring (16) is arranged on the fixed ring (14) in the middle of the two limiting pins (15). The torsion spring (16) abuts against the limiting pins (15); A through groove is also opened on the side wall of the outer rod (9). The movable end of the limiting pin (15) penetrates through the through groove and abuts against one of the limiting grooves (13).

4. The architectural decoration arc wall surface grinding device according to claim 3, characterized in that, An adjusting rod (17) is slidably arranged on the inner wall of the inner rod (10). The adjusting rod (17) is rotatably connected to the outer rod (9). A driven bevel gear (18) is fixedly arranged at one end of the adjusting rod (17). A driving bevel gear (19) is meshed on one side of each driven bevel gear (18). The two driving bevel gears (19) are fixedly connected by a fixed rod (20); An output bevel gear (21) is fixedly arranged in the middle of each fixed rod (20). An input bevel gear (22) is meshed on one side of the output bevel gear (21). The input bevel gear (22) is rotatably connected to the frame (1); The two input bevel gears (22) are fixedly connected by a connecting rod (23).

5. The abrasive device for the arc-shaped wall surface of building decoration according to claim 3, characterized in that, A passive bevel gear (24) is fixedly arranged in the middle of the connecting rod (23); A control wheel (25) is arranged on the frame (1). A plug rod is fixedly arranged on the control wheel (25). The plug rod is slidably connected with the frame (1). A driving bevel gear (26) is fixedly arranged at the movable end of the plug rod. A spring (27) is sleeved outside the plug rod. Two ends of the spring (27) are respectively abutted against the frame (1) and the control wheel (25). When the control wheel (25) is pressed, the spring (27) is compressed, and the driving bevel gear (26) meshes with the driven bevel gear (24).

6. The abrasive polishing device for the arc-shaped wall surface of building decoration according to claim 2, wherein, The radian adjusting mechanism (7) includes chutes opened on two sides of the frame (1). Two sliders (28) are slidably arranged in each chute. A connecting rod (29) is rotatably arranged on each slider (28). The movable end of the connecting rod (29) is rotatably connected with an adjacent outer rod (9).

7. The architectural decoration arc wall surface grinding device according to claim 6, characterized in that, A bidirectional lead screw (30) is rotatably arranged in the chute. Two sliders (28) located in the same chute are respectively threadedly connected with one end of the bidirectional lead screw (30). A worm gear (31) is fixedly arranged in the middle of the bidirectional lead screw (30). A worm (32) is rotatably arranged on each of two sides of the frame (1). The worm (32) meshes with an adjacent worm gear (31). The two worms (32) are fixedly connected through a transmission rod (33). A hand wheel (34) is fixedly arranged on one of the worms (32). The hand wheel (34) is coaxially fixed with the transmission rod (33).

8. The architectural decoration arc-shaped wall surface grinding device according to claim 1, characterized in that The grinding roller (4) is in a cylindrical shape. A driven sprocket (35) is fixedly arranged at one end of the grinding roller (4). A grinding motor (5) is fixedly arranged on the frame (1). A driven sprocket (35) is coaxially fixed on the motor shaft of the grinding motor (5). The driving sprocket (36) is connected with the driven sprocket (35) through a chain (37). A plurality of convex platforms are arranged on the side wall of the grinding roller (4). Each convex platform is spirally arranged on the outer surface of the grinding roller (4).

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