A wall surface grinding device for architectural decoration

Abstract

The present invention belongs to the field of construction, and particularly relates to a wall surface grinding device for architectural decoration. A wall surface grinding device for architectural decoration that can improve the grinding efficiency and facilitate grinding of corners, comprising a connection part for holding by hand and connecting to an external device, an installation part for installing a grinding mechanism, the installation part being capable of adjusting the position of the grinding mechanism, a wall grinding part for grinding the wall, and a corner grinding part for grinding the corners of the wall. By holding the connection part by hand, the wall surface can be quickly ground through the wall grinding part, improving the work efficiency; through the corner grinding part, the corners of the wall can be ground, enabling the wall to be comprehensively ground and improving the aesthetics of the wall; through the dust suction part, the dust generated during wall grinding can be quickly cleaned, better protecting the health of the staff.

Description

Technical Field

[0001] The present invention belongs to the field of construction, and particularly relates to a wall surface grinding device for building decoration. Background Art

[0002] With the booming development of the building decoration industry, people's requirements for the wall decoration effect are increasing day by day. The flatness and smoothness of the wall surface directly affect the adhesion effect of subsequent decorative materials such as paints and wallpapers and the overall aesthetics. Therefore, wall surface grinding has become a key link in building decoration construction.

[0003] Traditional wall surface grinding mainly relies on manual operation of handheld grinding tools such as sandpaper and grinding wheels. Workers need to hold the tools for a long time and repeatedly grind on the wall by experience and physical strength. This method has many drawbacks. On the one hand, manual grinding is extremely inefficient. Especially when dealing with large-area walls, it consumes a large amount of labor and time costs, seriously delaying the project progress. Taking the wall grinding of an ordinary residence as an example, if only relying on a skilled worker, it may take several days to complete the preliminary grinding of all walls, not including the subsequent fine grinding process.

[0004] On the other hand, when grinding the corners of the wall, due to the angle problem, it is very difficult for the tool to reach the edge of the corner for grinding. Therefore, after the wall is ground, it will be found that there are obvious deviations at the corner positions, which affects the aesthetics.

[0005] Therefore, there is an urgent need to develop a wall surface grinding device for building decoration that can improve the grinding efficiency and facilitate the grinding of corners. Summary of the Invention

[0006] In order to overcome the above-mentioned shortcomings of the prior art, the present invention provides a wall surface grinding device for building decoration that can improve the grinding efficiency and facilitate the grinding of corners.

[0007] The technical solution of the present invention is as follows: A wall surface grinding device for building decoration includes a connection part for holding by hand and connecting with an external device, an installation part for installing a grinding mechanism, the installation part can adjust the position of the grinding mechanism, a wall grinding part for grinding the wall, and a corner grinding part for grinding the corners of the wall; there is a grinding disc in the wall grinding part, and the corner grinding part includes a guide rod, a grinding block, a spring III, and a clamping shaft. At least two guide rods are evenly spaced at the eccentric position of the grinding disc, the guide rods are all slidably connected with the grinding blocks, the left side surface of the grinding block is in the same vertical plane as the outer side surface of the grinding disc, a spring III is connected between the grinding block and the grinding disc, and a clamping shaft is fixedly connected to the right side of the grinding disc.

[0008] Furthermore, the connecting part includes a connecting rod, a sliding rod, a clamping piece, a threaded sleeve, a connecting hose, a connecting plate and a connecting head. The lower part of the connecting rod is slidably connected with the sliding rod. The upper part of the sliding rod is provided with an external thread. The top of the sliding rod is provided with a clamping piece that indents inward in a circle. The external thread at the upper part of the sliding rod is threadedly connected with a threaded sleeve. The upper part of the threaded sleeve has a tapered part that indents inward. The tapered part of the threaded sleeve is outside the clamping piece. The top of the connecting rod is connected with a connecting hose. The top of the connecting hose is connected with a connecting head. A connecting plate is fixedly connected between the connecting head and the outside of the connecting rod.

[0009] Furthermore, the installation part includes a support plate, a rotating frame, a fastening bolt I, an installation cover and a fastening bolt II. Symmetrically arranged on the outside of the connecting head are support plates extending upward. Between the tops of the support plates is a rotatable connection with a rotating frame. The rotating frame can be fixed on the support plates through the fastening bolt I. The upper part of the rotating frame is provided with an installation cover that can rotate on its own. The installation cover is fixed on the rotating frame through the fastening bolt II.

[0010] Furthermore, the wall grinding part includes a grinding motor, a transmission box, a transmission shaft, a grinding disc, a clamping disc, a spring I, a clamping block and a spring II. The right side of the installation cover is fixedly connected with a grinding motor. The output shaft of the grinding motor is connected with a transmission shaft through a transmission box. A grinding disc is rotatably arranged concentrically on the left side of the installation cover. The transmission shaft passes through the grinding disc. The transmission shaft is slidably connected with a clamping disc by means of a key. A spring I is connected between the clamping disc and the installation cover. The left and right parts of the clamping disc are slidably connected. A spring II is sleeved on the transmission shaft between the clamping disc and the transmission box. At the eccentric position on the left side of the clamping disc, clamping blocks are evenly spaced and arranged. The clamping blocks are clamped into the grinding disc.

[0011] Furthermore, a pushing part is also included. The pushing part is symmetrically and fixedly arranged on the front and rear of the right side of the installation cover. The pushing part includes installation blocks symmetrically arranged on the right side of the installation cover and wedge-shaped blocks slidably installed on the installation blocks.

[0012] Furthermore, a vibrating part is also included. The vibrating part is arranged on the right side inside the installation cover. The vibrating part includes a transmission pulley group, an eccentric wheel, a large transmission wheel and a small transmission wheel. The transmission pulley group is rotatably arranged evenly spaced on the right side inside the installation cover. The transmission pulley group is composed of a small pulley, a large pulley and a transmission belt. The transmission belt is wound between the small pulley and the large pulley. The eccentric wheel is arranged on the left side of the large pulley in the transmission pulley group. The small transmission wheel is arranged on the left side of the small pulley. A large transmission wheel is arranged at the center of the right side of the clamping disc.

[0013] Furthermore, a dust suction part is also included. The dust suction part includes a dust suction pipe installed between the installation cover and the connecting head. A dust inlet hole is opened on the grinding disc on the left side of the dust suction pipe.

[0014] Furthermore, a protective layer is wrapped around the edge of the grinding block.

[0015] The beneficial effects are as follows: By holding the connection part, the wall grinding part of the present invention can quickly grind the wall surface, improving work efficiency; through the corner grinding part, the corners of the wall can be ground, enabling the wall to be comprehensively ground and improving the aesthetics of the wall; through the dust suction part, the dust generated during wall grinding can be quickly cleaned, better protecting the health of the staff. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0017] Figure 1 It is a three-dimensional structure diagram of the present invention.

[0018] Figure 2 It is a three-dimensional structure diagram of another perspective of the present invention.

[0019] Figure 3 It is a three-dimensional structure diagram of the connection part of the present invention.

[0020] Figure 4 It is a three-dimensional structure diagram of the installation part of the present invention.

[0021] Figure 5 It is a three-dimensional structure diagram of the components inside the installation cover of the present invention.

[0022] Figure 6 It is a three-dimensional structure diagram of the wall grinding part of the present invention.

[0023] Figure 7 It is a cross-sectional view of the clamping disc of the present invention.

[0024] Figure 8 For the present invention Figure 7 An enlarged view of part B.

[0025] Figure 9 For the present invention Figure 5 An enlarged view of part A.

[0026] Figure 10 It is a three-dimensional structure diagram of the vibration part of the present invention.

[0027] Figure 11 It is a three-dimensional structure diagram of the pushing part of the present invention.

[0028] Figure 12 It is a three-dimensional structure diagram of the dust suction part of the present invention.

[0029] Reference numerals in the drawings: 1 - connecting part, 101 - connecting rod, 102 - sliding rod, 103 - clamping piece, 104 - threaded sleeve, 105 - connecting hose, 106 - connecting plate, 107 - connecting head, 2 - mounting part, 201 - support plate, 202 - rotating frame, 203 - fastening bolt I, 204 - mounting cover, 205 - fastening bolt II, 3 - wall grinding part, 301 - grinding motor, 302 - transmission box, 303 - transmission shaft, 304 - grinding disc, 305 - clamping disc, 306 - spring I, 307 - clamping block, 308 - spring II, 4 - corner grinding part, 401 - guide rod, 402 - grinding block, 403 - spring III, 404 - clamping shaft, 5 - pushing part, 501 - mounting block, 502 - wedge block, 6 - vibrating part, 601 - transmission pulley set, 602 - eccentric wheel, 603 - large transmission wheel, 604 - small transmission wheel, 7 - dust suction part, 701 - dust inlet hole, 702 - dust suction pipe. Detailed implementation manners

[0030] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0031] Therefore, a feature pointed out in this specification will be used to illustrate one of the features of one embodiment of the present invention, rather than implying that each embodiment of the present invention must have the illustrated feature. In addition, it should be noted that this specification describes many features. Although some features may be combined to show possible system designs, these features can also be used in other combinations not specifically described. Therefore, unless otherwise stated, the illustrated combinations are not intended to be limiting.

[0032] In the description of the present application, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present application 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 application.

[0033] The technical solution of the present invention will be further described below with reference to the accompanying drawings.

[0034] Embodiment: A wall surface grinding device for building decoration, as Figures 1-9As shown in the figure, it includes a connecting part 1 for hand-holding and connecting to an external device, a mounting part 2 for mounting a grinding mechanism, the mounting part 2 being able to adjust the position of the grinding mechanism, a wall grinding part 3 for grinding a wall, and a corner grinding part 4 for grinding the corners of a wall.

[0035] As Figure 3 shown in the figure, the connecting part 1 includes a connecting rod 101, a sliding rod 102, a clamping piece 103, a threaded sleeve 104, a connecting hose 105, a connecting plate 106, and a connecting head 107. A sliding rod 102 is slidably connected to the lower part of the connecting rod 101. The upper part of the sliding rod 102 is provided with an external thread. A clamping piece 103 that indents inward is provided at the top of the sliding rod 102. A threaded sleeve 104 is threadedly connected to the external thread of the upper part of the sliding rod 102. The upper part of the threaded sleeve 104 has a tapered part that indents inward. The tapered part of the threaded sleeve 104 is outside the clamping piece 103. By screwing down the threaded sleeve 104, the clamping piece 103 can be pressed tightly against the outer surface of the connecting rod 101 to fix the sliding rod 102 on the connecting rod 101. A connecting hose 105 is connected to the top of the connecting rod 101. A connecting head 107 is connected to the top of the connecting hose 105. A connecting plate 106 is fixedly connected between the connecting head 107 and the outside of the connecting rod 101 by bolts. The connecting rod 101, the sliding rod 102, and the connecting head 107 are all in a hollow state.

[0036] As Figure 4 shown in the figure, the mounting part 2 includes a support plate 201, a rotating frame 202, a fastening bolt I 203, a mounting cover 204, and a fastening bolt II 205. Support plates 201 that extend upward symmetrically are provided on the outside of the connecting head 107. A rotating frame 202 is rotatably connected between the tops of the support plates 201. The rotating frame 202 can be fixed on the support plates 201 by the fastening bolt I 203 so that the rotating frame 202 cannot rotate. An installable cover 204 that can rotate by itself is provided on the upper part of the rotating frame 202. The mounting cover 204 is fixed on the rotating frame 202 by the fastening bolt II 205. By the fastening bolt II 205, the mounting cover 204 can be fixed on the rotating frame 202 so that it cannot rotate.

[0037] As Figures 6-8As shown in the figure, the wall grinding part 3 includes a grinding motor 301, a transmission box 302, a transmission shaft 303, a grinding disc 304, a clamping disc 305, a spring I 306, a clamping block 307 and a spring II 308. The right side of the installation cover 204 is fixedly connected with the grinding motor 301 by bolts. The output shaft of the grinding motor 301 is connected with the transmission shaft 303 through the transmission box 302. The transmission box 302 is driven by gears or pulleys. The transmission shaft 303 is at the center of the right side of the installation cover 204. The grinding disc 304 is rotatably arranged concentrically on the left side of the installation cover 204. The transmission shaft 303 passes through the grinding disc 304. The clamping disc 305 is slidably connected to the transmission shaft 303 by means of a key. A spring I 306 is connected between the clamping disc 305 and the installation cover 204. The left and right parts of the clamping disc 305 are slidably connected. The sliding part of the clamping disc 305 is on the left side of the spring I 306. A spring II 308 is sleeved on the transmission shaft 303 between the clamping disc 305 and the transmission box 302. The right end of the spring II 308 is fixedly connected to the transmission box 302, and the left end of the spring II 308 contacts the clamping disc 305. The clamping blocks 307 are evenly spaced at the eccentric position on the left side of the clamping disc 305. The clamping blocks 307 are clamped into the grinding disc 304, so that the grinding disc 304 can rotate together with the clamping disc 305.

[0038] As Figure 9 shown in the figure, the corner grinding part 4 includes a guide rod 401, a grinding block 402, a spring III 403 and a clamping shaft 404. Four guide rods 401 are evenly spaced at the eccentric position of the grinding disc 304. The grinding blocks 402 are slidably connected to the guide rods 401. The left side surface of the grinding block 402 and the outer side surface of the grinding disc 304 are in the same vertical plane. A spring III 403 is connected between the grinding block 402 and the grinding disc 304. The right side of the grinding disc 304 is fixedly connected with the clamping shaft 404 by bolts. When in the initial state, the clamping shaft 404 is stuck at the edge of the inner side surface of the clamping disc 305. At this time, the spring III 403 is in a stretched state. A protective layer is wrapped around the edge of the grinding block 402 to prevent the edge of the grinding block 402 from damaging the adjacent wall head.

[0039] When using this device to polish the wall, first loosen the threaded sleeve 104, pull the sliding rod 102 downward to the required length, then tighten the threaded sleeve 104 to fix the sliding rod 102. Then loosen the fastening bolt I 203 and the fastening bolt II 205. At this time, adjust the angle of the mounting cover 204 and its components. Then tighten the fastening bolt I 203 and the fastening bolt II 205, and the angle of the mounting cover 204 and its components is fixed. Then control the polishing motor 301 to start working. Drive the transmission shaft 303 to start rotating through the transmission case 302, so as to drive the left part of the clamping disc 305 to start rotating, and then drive the polishing disc 304 to start rotating. Then hold the sliding rod 102 by hand and align the polishing disc 304 with the polishing position of the wall to start polishing. When it is necessary to polish the corner of the wall, first control the polishing motor 301 to stop working. Then pull the clamping disc 305 to the right. At this time, the spring I 306 and the spring II 308 are compressed, and at the same time, the clamping block 307 is separated from the polishing disc 304, and the clamping shaft 404 is no longer limited by the clamping disc 305. The spring III 403 in the stretched state resets, driving the polishing block 402 to move outward. Then polish the corner of the wall through the polishing block 402. After the corner of the wall is polished, first push the polishing block 402 to move inward to reset, and the spring III 403 is stretched again. At this time, release the clamping disc 305. Under the action of the reset of the spring I 306 and the spring II 308, the clamping disc 305 moves to the left to reset, and the clamping shaft 404 is clamped again. At the same time, the clamping block 307 is re-clamped on the polishing disc 304.

[0040] As Figure 11 shown, it further includes a pushing part 5. The right side surface of the mounting cover 204 is symmetrically fixed with the pushing part 5 before and after by bolts. The pushing part 5 includes mounting blocks 501 symmetrically arranged on the right side surface of the mounting cover 204, and wedge-shaped blocks 502 slidably mounted on the mounting blocks 501. The wedge-shaped surface of the wedge-shaped block 502 faces to the right, and the leftmost side of the inclined surface of the wedge-shaped block 502 is on the left side of the right part of the clamping disc 305.

[0041] When pushing the clamping disc 305 to the right, the wedge-shaped block 502 can be squeezed inward. The wedge-shaped block 502 pushes the clamping disc 305 to move to the right. When the non-inclined surface part on the right side of the wedge-shaped block 502 contacts the clamping disc 305, the clamping disc 305 is clamped to prevent the clamping disc 305 from moving to the left to reset. In this way, it is more convenient to use this device.

[0042] As Figure 10As shown in the figure, it further includes a vibration part 6. The vibration part 6 is arranged on the right inner side of the mounting cover 204. The vibration part 6 includes a transmission pulley group 601, an eccentric wheel 602, a large transmission wheel 603 and a small transmission wheel 604. The transmission pulley group 601 is rotatably arranged on the right inner side of the mounting cover 204 at equal intervals. The transmission pulley group 601 is composed of a small pulley, a large pulley and a transmission belt. The transmission belt is wound between the small pulley and the large pulley. The eccentric wheel 602 is arranged on the left side of the large pulley in the transmission pulley group 601. The small transmission wheel 604 is arranged on the left side of the small pulley. A large transmission wheel 603 is arranged at the center of the right side of the clamping disc 305. The large transmission wheel 603 can drive the small transmission wheel 604 to rotate.

[0043] When grinding the corner of the wall, the clamping disc 305 moves to the right, so that the large transmission wheel 603 moves to the right. When the non-inclined part on the right side of the wedge block 502 contacts the clamping disc 305, the large transmission wheel 603 meshes with the small transmission wheel 604. At this time, control the grinding motor 301 to start working. Drive the large transmission wheel 603 to rotate through the grinding motor 301, and then drive the small transmission wheel 604 to rotate, so as to drive the eccentric wheel 602 to rotate through the transmission pulley group 601. The rotation of the eccentric wheel 602 generates vibration, so that the grinding block 402 vibrates to grind the corner of the wall. After the corner of the wall is ground, control the grinding motor 301 to stop working. At this time, move the clamping disc 305 to the left to reset, and the large transmission wheel 603 is disengaged from the small transmission wheel 604.

[0044] As Figure 12 shown in the figure, it further includes a dust suction part 7. The dust suction part 7 includes a dust suction pipe 702 installed between the mounting cover 204 and the connecting head 107. A dust inlet hole 701 is opened on the grinding disc 304 on the left side of the dust suction pipe 702. Dust is sucked in through the dust inlet hole 701, and then discharged through the dust suction pipe 702, the connecting head 107, the connecting rod 101 and the sliding rod 102.

[0045] When grinding the wall, dust enters the dust suction pipe 702 through the dust inlet hole 701. At the same time, contact the bottom end of the sliding rod 102 with the vacuum cleaner, and the dust generated by grinding is sucked away through the dust suction pipe 702, the connecting head 107, the connecting rod 101 and the sliding rod 102.

[0046] The technical principle of the embodiments of the present invention has been described above in combination with specific embodiments. These descriptions are only for explaining the principle of the embodiments of the present invention, and cannot be interpreted in any way as a limitation on the protection scope of the embodiments of the present invention. Based on the explanations here, those skilled in the art can think of other specific implementation manners of the embodiments of the present invention without creative labor, and these manners will fall within the protection scope of the embodiments of the present invention.

Claims

1. A wall surface polishing device for building decoration, comprising a connecting portion (1) for holding and connecting to an external device, a mounting portion (2) for mounting a polishing mechanism, the mounting portion (2) being capable of adjusting the position of the polishing mechanism, a wall polishing portion (3) for polishing a wall, and a corner polishing portion (4) for polishing a wall corner, the wall polishing portion (3) and the corner polishing portion (4) being both mounted on a mounting cover (204) in the mounting portion (2); characterized in that: The wall polishing part (3) contains a polishing disc (304), and the corner polishing part (4) comprises a guide rod (401), a polishing block (402), a spring III (403) and a clamping shaft (404). At least two guide rods (401) are evenly spaced at an eccentric position of the polishing disc (304), and the guide rods (401) are slidably connected to the polishing blocks (402). The left side of the polishing block (402) and the outer side of the polishing disc (304) are on the same vertical plane. A spring III (403) is connected between the polishing block (402) and the polishing disc (304), and the right side of the polishing disc (304) is fixedly connected to the clamping shaft (404); the wall polishing part (3) comprises a polishing motor (301 ), a transmission box (302), a transmission shaft (303), a grinding disc (304), a clamping disc (305), a spring I (306), a clamping block (307) and a spring II (308); a grinding motor (301) is fixedly connected to the right side of the mounting cover (204); a transmission shaft (303) is connected to the output shaft of the grinding motor (301) through a transmission box (302); a grinding disc (304) is coaxially arranged on the left side of the mounting cover (204); the transmission shaft (303) passes through the grinding disc (304); a clamping disc (305) is slidably connected to the transmission shaft (303) by means of a key; a spring is connected between the clamping disc (305) and the mounting cover (204) Ⅰ (306), the left and right parts of the clamping plate (305) are slidably connected, a spring II (308) is sleeved on the transmission shaft (303) between the clamping plate (305) and the transmission box (302), and clamping blocks (307) are evenly spaced at the eccentric position on the left side of the clamping plate (305), and the clamping blocks (307) are clamped into the grinding plate (304); it also includes a pushing part (5), the pushing part (5) is symmetrically fixedly arranged on the front and rear sides of the right side of the mounting cover (204), and the pushing part (5) includes a mounting block (501) symmetrically arranged on the right side of the mounting cover (204), and a wedge block (502) slidably mounted on the mounting block (501); it also includes a vibrating part (6), the mounting cover A vibration part (6) is arranged on the right side of the inner part (204), and the vibration part (6) includes a transmission pulley group (601), an eccentric wheel (602), a large transmission wheel (603) and a small transmission wheel (604). A transmission pulley group (601) is evenly arranged on the right side of the inner part of the mounting cover (204) for rotation. The transmission pulley group (601) is composed of a small pulley, a large pulley and a transmission belt. The transmission belt is wound between the small pulley and the large pulley. The eccentric wheel (602) is arranged on the left side of the large pulley in the transmission pulley group (601), and the small transmission wheel (604) is arranged on the left side of the small pulley. The large transmission wheel (603) is arranged at the center of the right side of the clamping plate (305).

2. A wall surface polishing device for building decoration as claimed in claim 1, characterized in that: The connecting portion (1) comprises a connecting rod (101), a sliding rod (102), a clamping sheet (103), a threaded sleeve (104), a connecting hose (105), a connecting plate (106) and a connecting head (107). The lower portion of the connecting rod (101) is slidably connected to the sliding rod (102). The upper portion of the sliding rod (102) is provided with an external thread. The top of the sliding rod (102) is provided with a circle of clamping sheets (103) that are retracted inwards. The external thread on the upper portion of the sliding rod (102) is threadedly connected to the threaded sleeve (104). The upper portion of the threaded sleeve (104) is provided with a tapered portion that is retracted inwards. The tapered portion of the threaded sleeve (104) is located outside the clamping sheet (103). The top of the connecting rod (101) is connected to the connecting hose (105). The top of the connecting hose (105) is connected to the connecting head (107). The connecting plate (106) is fixedly connected between the connecting head (107) and the outer side of the connecting rod (101).

3. A wall surface grinding device for building decoration as claimed in claim 2, characterized in that: The mounting portion (2) comprises a support plate (201), a rotating frame (202), a fastening bolt I (203), a mounting cover (204) and a fastening bolt II (205); a support plate (201) extending upward is symmetrically arranged on the outer side of the connecting head (107); a rotating frame (202) is rotatably connected between the tops of the support plates (201); the rotating frame (202) can be fixed to the support plate (201) by means of the fastening bolt I (203); a mounting cover (204) capable of self-rotation is arranged on the upper part of the rotating frame (202); and the mounting cover (204) is fixed to the rotating frame (202) by means of the fastening bolt II (205).

4. A wall surface grinding device for building decoration as claimed in claim 3, characterized in that: It also comprises a dust suction part (7), the dust suction part (7) comprising a dust suction pipe (702) installed between the installation cover (204) and the connecting head (107), and a dust inlet hole (701) is provided on the grinding disc (304) on the left side of the dust suction pipe (702).

5. A wall surface grinding device for building decoration as claimed in claim 4, characterized in that: The edge of the grinding block (402) is wrapped with a protective layer.

Images