Textile roller cleaning device

Abstract

The utility model relates to textile roller technical field especially relates to a textile roller cleaning device, including bottom plate, the left side fixed mounting of bottom plate top is vertical fixed plate, the right side installation of bottom plate top is movable movable plate, and the roller body is clamped between fixed plate and movable plate, the right side fixed mounting of fixed plate is the horizontal guide plate of showing, the side surface of movable plate is opened and has the through -opening, the right -hand member of guide plate penetrates through the through -opening, and the slot of going up and down is opened to guide plate, and the support plate of being located movable plate right side is fixedly installed between guide plate right end and bottom plate, and support plate shows inverted U shape, and the first drive assembly connected with movable plate is installed in bottom plate top, and the second drive assembly is installed in the slot left side with guide plate. The utility model through multiple component cooperation, realized the efficient, thorough cleaning of textile roller, and the operation convenience and equipment versatility are considered simultaneously, are suitable for the maintenance cleaning demand of all kinds of textile roller in textile production.

Description

Technical Field

[0001] This utility model relates to the field of textile roller technology, and in particular to a textile roller cleaning device. Background Technology

[0002] In the textile production process, textile rollers are key components. Their surfaces are easily contaminated with impurities such as lint, thread ends, and dust. If they are not cleaned in time, they will not only affect the quality of textiles, such as causing fabric defects and uneven textures, but the accumulation of impurities may also lead to accelerated wear of the textile rollers, shorten their service life, and increase production and maintenance costs.

[0003] Currently, existing textile roller cleaning devices have many shortcomings. Common cleaning devices use a single cleaning method, which is difficult to simultaneously remove stubborn impurities and clean residual dust on the surface, resulting in incomplete cleaning. Moreover, most cleaning components are fixedly installed, making disassembly and replacement difficult when the scraper wears down or the brush ages, resulting in poor maintenance convenience. In addition, fixed cleaning components can only be adapted to textile rollers of a specific length, lacking versatility for rollers of different specifications. Therefore, this application proposes a textile roller cleaning device. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a textile roller cleaning device to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a textile roller cleaning device, comprising:

[0006] The base plate has a vertical fixed plate fixedly installed on the top left side and a movable sliding plate installed on the top right side.

[0007] The roller is held between the fixed plate and the moving plate;

[0008] The guide plate is horizontally fixed on the right side of the fixed plate. The side of the movable plate has an opening, the right end of the guide plate passes through the opening, and the guide plate has a through slot running vertically.

[0009] The support plate, in the shape of an inverted U, is located on the right side of the movable plate and is fixedly installed between the right end of the guide plate and the base plate;

[0010] The first drive assembly is mounted on top of the base plate and connected to the moving plate;

[0011] The second drive assembly is installed on the left side of the fixed plate and extends into the slot;

[0012] The cleaning mechanism is sleeved on the outside of the roller body and installed on the second drive assembly.

[0013] Furthermore, a first sleeve is fixedly installed on the top right side of the fixed plate, and a second sleeve is fixedly installed on the top left side of the movable plate. The first and second sleeves are symmetrically distributed. Both ends of the roller are provided with rod shafts, and the rod shafts at both ends of the roller are inserted into the first and second sleeves respectively.

[0014] Furthermore, the first drive assembly includes a first motor and a first screw. A first screw hole is provided on the side of the movable plate below the opening. The first motor is fixedly installed on the top right end of the base plate. The first screw is fixedly connected to the output end of the first motor and passes through the support plates and threaded through the first screw hole on the movable plate. A circular hole is provided on the side of the fixed plate, and a first bearing is fixedly installed in the circular hole. One end of the first screw that passes through the movable plate is fixedly inserted into the first bearing. Two guide rods are fixedly installed at the lower right side of the fixed plate. The two guide rods are located on both sides of the first screw, and the right ends of the two guide rods are set vertically and fixedly connected to the base plate. Guide holes are provided on both sides of the movable plate at the first screw hole, and the two guide holes on the movable plate are respectively fitted onto the two guide rods.

[0015] Furthermore, the second drive assembly includes a second motor, a second screw, and an I-shaped sliding block. The second motor is fixedly mounted on the left side of the fixed plate. The second screw is fixedly connected to the output end of the second motor and passes through the fixed plate, extending into a slot on the guide plate. A groove is provided at the right end of the slot, and a second bearing is fixedly installed in the groove. The right end of the second screw is fixedly inserted into the second bearing. The sliding block is slidably mounted in the slot on the guide plate, and a second screw hole is provided on the side of the sliding block, which is fitted onto the second screw. A vertical support rod is fixedly mounted on the top of the sliding block, and a cleaning mechanism is fixedly mounted on the top of the support rod.

[0016] Furthermore, the cleaning mechanism includes a ring, a bearing disc, a rotating ring, a third drive assembly, and a cleaning assembly. The ring is sleeved outside the first sleeve and coaxially arranged therewith, and the ring is fixedly installed on the top of the support rod. The bearing disc is fixedly installed on the inner wall of the ring, the rotating ring is fixedly installed between the bearing discs, the third drive assembly is fixedly installed on the top of the ring and connected to the rotating ring, and the cleaning assembly is detachably installed inside the rotating ring.

[0017] Furthermore, the top of the ring is set as a flat platform, and a notch is opened on the right side of the top of the ring. The third drive component includes a third motor, a gear and a gear ring. The gear ring is fixedly sleeved on the outside of the rotating ring. The third motor is fixedly installed on the platform at the top of the ring. The gear is fixedly installed on the output end of the third motor, and the bottom end of the gear passes through the notch and meshes with the top of the gear ring.

[0018] Furthermore, the cleaning assembly includes a ring body, scrapers, and brushes. A ring-shaped inner edge plate is provided on the left side of the inner wall of the rotating ring. A third screw hole is provided at both ends of the inner edge plate. The ring body is placed inside the rotating ring and fits against the inner edge plate. A third screw rod is fixedly installed at both ends of the right side of the ring body and inserted into the corresponding third screw hole. A nut is threaded onto one end of each of the two third screw rods that passes through the inner edge plate. Multiple scrapers are arranged in a circular array and installed on the right half of the inner wall of the ring body. The scrapers are arc-shaped, and the end of the scraper away from the ring body can fit against the outer wall of the roller body. Multiple brushes are arranged in a circular array and installed on the left half of the inner wall of the ring body, and the brushes can contact the outer wall of the roller body.

[0019] Furthermore, a first ball groove is provided at both ends of the bottom of the movable plate, and a rotatable first ball is provided in each of the two first ball grooves. The part of each first ball extending out of the first ball groove contacts the bottom plate. A second ball groove is provided at the corners of the top and bottom of the opening, and a rotatable second ball is provided in each of the second ball grooves. The part of each second ball extending out of the second ball groove contacts the guide plate.

[0020] The beneficial effects of this utility model are:

[0021] The second drive component enables the horizontal movement of the cleaning mechanism. The cleaning component in the cleaning mechanism is equipped with both an arc-shaped scraper and a brush. The scraper can remove stubborn impurities (such as clumps of cotton wool and thread ends) from the surface of the roller, while the brush can sweep away residual dust and fine fibers. The combination of the two cleaning methods solves the problem of incomplete cleaning caused by the single cleaning method of the existing device, and effectively avoids the impact of impurity residue on the quality of textiles.

[0022] The cleaning component is detachably connected to the inner edge plate of the rotating ring via a third screw and nut. When the scraper wears or the brush ages, the cleaning component can be removed and replaced simply by unscrewing the nut and pulling out the third screw. No complicated operation is required, which solves the problem of difficult disassembly and replacement caused by the fixed installation of the cleaning components in the existing device, reduces maintenance costs and time, and also allows for the replacement of the cleaning component with a scraper and brush that are compatible with the size of the roller to be cleaned.

[0023] With the help of the first drive assembly, the movable plate can move left and right along the guide rod. By adjusting the distance between the fixed plate and the movable plate, it can adapt to rollers of different lengths (as long as the rod shafts at both ends of the roller can be inserted into the first and second sleeves). This breaks through the limitation of existing devices that can only adapt to textile rollers of specific lengths and expands the applicability of the device. Attached Figure Description

[0024] Other features, objects, and advantages of this invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0026] Figure 2 This is a schematic diagram of the structure of the base plate, fixed plate, movable plate, guide plate and roller body of this utility model;

[0027] Figure 3 This is a structural schematic diagram of the first drive assembly, the second drive assembly, and the moving plate of this utility model in cross-section.

[0028] Figure 4 This is a schematic diagram of the connection between the base plate, the fixing plate, and the guide plate of this utility model;

[0029] Figure 5 This is a schematic diagram of the connection between the sliding block and the cleaning mechanism of this utility model;

[0030] Figure 6 This is a cross-sectional structural diagram of the cleaning mechanism of this utility model;

[0031] Figure 7 This is an exploded view of the cleaning mechanism of this utility model;

[0032] Figure 8 This is a schematic diagram of the structure of the rotating ring and the toothed ring of this utility model;

[0033] Figure 9 This is a schematic diagram of the cleaning component of this utility model;

[0034] In the picture:

[0035] 11. Base plate; 12. Fixed plate; 13. First sleeve; 14. Moving plate; 15. Second sleeve; 16. Guide plate; 17. Support plate;

[0036] 141. Through port; 142. First screw hole; 143. Guide hole; 144. First ball bearing; 145. Second ball bearing; 161. Groove;

[0037] 21. First motor; 22. First screw; 23. Guide rod;

[0038] 31. Second motor; 32. Second screw; 33. Sliding block;

[0039] 331. Second screw hole; 332. Support rod;

[0040] 4. Cleaning up the organization;

[0041] 41. Ring; 42. Bearing disc; 43. Rotating ring; 45. Cleaning assembly; 46. Third screw; 47. Nut;

[0042] 411. Notch; 431. Inner edge plate;

[0043] 441. Third motor; 442. Gear; 443. Gear ring;

[0044] 451. Ring body; 452. Scraper; 453. Brush;

[0045] 5. Roller body. Detailed Implementation

[0046] To make the technical means, creative features, objectives and effects of this utility model easier to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0047] Please see Figures 1-9 This utility model provides a technical solution: a textile roller cleaning device, including a base plate 11, a vertical fixed plate 12 fixedly installed on the left side of the top of the base plate 11, a movable moving plate 14 installed on the right side of the top of the base plate 11, a roller body 5 clamped between the fixed plate 12 and the moving plate 14, a horizontal guide plate 16 fixedly installed on the right side of the fixed plate 12, an opening 141 opened on the side of the moving plate 14, the right end of the guide plate 16 passing through the opening 141, a vertically through slot 161 opened on the guide plate 16, and a device located on the right side of the moving plate 14 fixedly installed between the right end of the guide plate 16 and the base plate 11. The side support plate 17 is inverted U-shape. A first drive assembly connected to the movable plate 14 is installed on the top of the base plate 11. A second drive assembly is installed on the left side of the fixed plate 12 and in the slot 161. A cleaning mechanism 4 sleeved on the outside of the roller body 5 is installed on the second drive assembly. The roller body 5 is clamped by the fixed plate 12 and the movable plate 14. Combined with the structural design of the guide plate 16 and the support plate 17, a stable installation foundation and running guide are provided for the subsequent second drive assembly and cleaning mechanism 4. The overall layout is compact and highly functional, which can realize efficient positioning and cleaning of the roller body 5.

[0048] like Figure 1 and Figure 2 As shown, a first sleeve 13 is fixedly installed on the top right side of the fixed plate 12, and a second sleeve 15 is fixedly installed on the top left side of the movable plate 14. The first sleeve 13 and the second sleeve 15 are symmetrically distributed. Both ends of the roller body 5 are provided with rod shafts, and the rod shafts at both ends of the roller body 5 are respectively inserted into the first sleeve 13 and the second sleeve 15. Through the insertion and cooperation of the rod shafts at both ends of the roller body 5 with the first sleeve 13 and the second sleeve 15, the roller body 5 can be quickly installed and stably clamped, which not only ensures the stability of the roller body 5 during the cleaning process, but also facilitates the picking and putting away of the roller body 5, thus improving the convenience of operation.

[0049] like Figure 2 and Figure 3As shown, the first drive assembly includes a first motor 21 and a first screw 22. A first screw hole 142 is provided on the side of the movable plate 14 below the through-hole 141. The first motor 21 is fixedly installed on the top right end of the base plate 11. The first screw 22 is fixedly connected to the output end of the first motor 21, and the first screw 22 passes through the support plates 17 and is threaded through the first screw hole 142 on the movable plate 14. A circular hole is provided on the side of the fixed plate 12, and a first bearing is fixedly installed in the circular hole. One end of the first screw 22 that passes through the movable plate 14 is fixedly inserted into the first bearing. Two guide rods 23 are fixedly installed at the lower right side of the fixed plate 12. The two guide rods 23 are respectively located at... The first screw 22 has two sides, and the right ends of the two guide rods 23 are set vertically and fixedly connected to the base plate 11. The side of the moving plate 14 and both sides of the first screw hole 142 are provided with guide holes 143. The two guide holes 143 on the moving plate 14 are respectively sleeved on the two guide rods 23. The first drive assembly drives the first screw 22 through the first motor 21. With the guidance of the guide rods 23, the moving plate 14 moves smoothly, thereby adjusting the distance between the fixed plate 12 and the moving plate 14 to adapt to rollers 5 of different lengths. At the same time, the ball bearing structure reduces moving friction, improves the smoothness of the moving plate 14's operation, and enhances the versatility and stability of the device.

[0050] like Figure 2 and Figure 3 As shown, the second drive assembly includes a second motor 31, a second screw 32, and an I-shaped sliding block 33. The second motor 31 is fixedly mounted on the left side of the fixed plate 12. The second screw 32 is fixedly connected to the output end of the second motor 31 and passes through the fixed plate 12, extending into a slot 161 on the guide plate 16. A groove is provided at the right end of the slot 161, and a second bearing is fixedly installed in the groove. The right end of the second screw 32 is fixedly inserted into the second bearing. The sliding block 33 is slidably mounted in the slot 161 on the guide plate 16, and a side opening of the sliding block 33 is provided. The second screw hole 331 is fitted onto the second screw 32. A vertical support rod 332 is fixedly installed on the top of the sliding block 33. The cleaning mechanism 4 is fixedly installed on the top of the support rod 332. The second drive assembly drives the second screw 32 through the second motor 31, causing the sliding block 33 to slide along the groove 161 on the guide plate 16, thereby realizing the movement of the cleaning mechanism 4 along the axial direction of the roller body 5. This ensures that the cleaning mechanism 4 can fully cover the surface of the roller body 5, avoid cleaning dead corners, and improve the comprehensiveness of cleaning. The matching design of the I-shaped sliding block 33 and the groove 161 ensures the stability of the sliding process.

[0051] like Figure 5 , Figure 6 and Figure 7As shown, the cleaning mechanism 4 includes a ring 41, a bearing disk 42, a rotating ring 43, a third drive assembly, and a cleaning assembly 45. The ring 41 is sleeved on the outside of the first sleeve 13 and coaxially arranged therewith, and the ring 41 is fixedly installed on the top of the support rod 332. The bearing disk 42 is fixedly installed on the inner wall of the ring 41, and the rotating ring 43 is fixedly installed between the bearing disks 42. The third drive assembly is fixedly installed on the top of the ring 41 and connected to the rotating ring 43. The cleaning assembly 45 is detachably installed inside the rotating ring 43. The cleaning mechanism 4 is designed to be sleeved on the outside of the roller body 5. The position is adjusted by the second drive assembly, and the rotation is driven by the third drive assembly, which can clean the side wall of the roller body 5 in all directions. The setting of the bearing disk 42 ensures the smooth rotation of the rotating ring 43, providing structural support for efficient cleaning.

[0052] like Figure 6 and Figure 7 As shown, the top of the ring 41 is set as a flat platform, and a notch 411 is opened on the right side of the top of the ring 41. The third drive assembly includes a third motor 441, a gear 442 and a gear ring 443. The gear ring 443 is fixedly sleeved on the outside of the rotating ring 43. The third motor 441 is fixedly installed on the platform at the top of the ring 41. The gear 442 is fixedly installed on the output end of the third motor 441, and the bottom end of the gear 442 passes through the notch 411 and meshes with the top of the gear ring 443. The third drive assembly drives the gear 442 to mesh with the gear ring 443 through the third motor 441, driving the rotating ring 43 to rotate. The transmission structure is simple and efficient, and the meshing connection between the gear 442 and the gear ring 443 ensures the stability of power transmission, enabling the cleaning mechanism 4 to rotate at a uniform speed and improving the uniformity of the cleaning effect.

[0053] like Figure 6 and Figure 8As shown, the cleaning component 45 includes a ring 451, a scraper 452, and a brush 453. An annular inner edge plate 431 is provided on the left side of the inner wall of the rotating ring 43. Third screw holes are provided at both ends of the inner edge plate 431. The ring 451 is placed inside the rotating ring 43 and fits against the inner edge plate 431. Third screws 46, which are inserted into the corresponding third screw holes, are fixedly installed at both ends of the right side of the ring 451. Nuts 47 are threaded onto the ends of the two third screws 46 that penetrate the inner edge plate 431. Multiple sets of scrapers 452 are arranged in a circular array and installed on the right half of the inner wall of the ring 451. 2 is set in an arc shape, and the end of the scraper 452 away from the ring 451 can be in contact with the outer wall of the roller 5. Multiple sets of brushes 453 are installed in a circular array on the left half of the inner wall of the ring 451, and the brushes 453 can contact the outer wall of the roller 5. The cleaning component 45 integrates the scraper 452 and the brushes 453. The scraper 452 can scrape off stubborn impurities, and the brushes 453 can sweep away residual dust. The combination of the two cleaning methods improves the thoroughness of cleaning. At the same time, the cleaning component 45 and the rotating ring 43 are detachably connected by the third screw 46 and the nut 47, which facilitates the replacement and maintenance of parts and reduces the cost of use.

[0054] like Figure 3 As shown, the bottom of the movable plate 14 has first ball grooves at both ends, and rotatable first balls 144 are provided in each of the two first ball grooves. The parts of the two first balls 144 extending out of the first ball grooves are in contact with the bottom plate 11. The top and bottom corners of the opening 141 have second ball grooves, and each second ball groove is provided with a rotatable second ball 145. The part of each second ball 145 extending out of the second ball groove is in contact with the guide plate 16. The first balls 144 at the bottom of the movable plate 14 and the second balls 145 at the opening 141 convert sliding friction into rolling friction, which greatly reduces the frictional resistance between the movable plate 14 and the bottom plate 11 and the guide plate 16, making the movement of the movable plate 14 smoother, reducing the load on the first drive assembly and the second drive assembly, and extending the service life of the device.

[0055] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A textile roller cleaning device, characterized in that, include: A base plate (11) is fixedly installed on the left side of the top of the base plate (11), and a movable plate (14) is installed on the right side of the top of the base plate (11). The roller (5) is held between the fixed plate (12) and the movable plate (14); The guide plate (16) is fixedly installed horizontally on the right side of the fixed plate (12). The side of the movable plate (14) has an opening (141). The right end of the guide plate (16) passes through the opening (141). The guide plate (16) has a slot (161) that runs vertically through it. The support plate (17) is in the shape of an inverted U and is located on the right side of the movable plate (14) and fixedly installed between the right end of the guide plate (16) and the base plate (11); The first drive assembly is mounted on top of the base plate (11) and connected to the movable plate (14); The second drive assembly is installed on the left side of the fixed plate (12) and extends into the slot (161); The cleaning mechanism (4) is sleeved on the outside of the roller body (5) and installed on the second drive assembly.

2. The textile roller cleaning device according to claim 1, characterized in that, The top right side of the fixed plate (12) is fixedly installed with a first sleeve (13), and the top left side of the movable plate (14) is fixedly installed with a second sleeve (15). The first sleeve (13) and the second sleeve (15) are symmetrically distributed. Both ends of the roller body (5) are provided with rod shafts, and the rod shafts at both ends of the roller body (5) are respectively inserted into the first sleeve (13) and the second sleeve (15).

3. The textile roller cleaning device according to claim 1, characterized in that, The first drive assembly includes a first motor (21) and a first screw (22). A first screw hole (142) is provided on the side of the movable plate (14) below the opening (141). The first motor (21) is fixedly mounted on the top right end of the base plate (11). The first screw (22) is fixedly connected to the output end of the first motor (21), and the first screw (22) passes through the support plates (17) and threaded through the first screw hole (142) on the movable plate (14). A circular hole is provided on the side of the fixed plate (12), and a first bearing is fixedly installed in the circular hole. The first screw (22) is fixedly inserted into the first bearing through one end of the movable plate (14). Two guide rods (23) are fixedly installed at the lower right side of the fixed plate (12). The two guide rods (23) are located on both sides of the first screw (22), and the right ends of the two guide rods (23) are set vertically and fixedly connected to the base plate (11). Guide holes (143) are opened on the side of the movable plate (14) on both sides of the first screw hole (142), and the two guide holes (143) on the movable plate (14) are respectively fitted onto the two guide rods (23).

4. The textile roller cleaning device according to claim 1, characterized in that, The second drive assembly includes a second motor (31), a second screw (32), and an I-shaped sliding block (33). The second motor (31) is fixedly installed on the left side of the fixed plate (12). The second screw (32) is fixedly connected to the output end of the second motor (31). The second screw (32) passes through the fixed plate (12) and extends into the slot (161) on the guide plate (16). A groove is provided at the right end of the slot (161). A second bearing is fixedly installed in the groove. The right end of the second screw (32) is fixedly inserted into the second bearing. The sliding block (33) is slidably installed in the slot (161) on the guide plate (16). A second screw hole (331) is provided on the side of the sliding block (33) and sleeved on the second screw (32). A vertical support rod (332) is fixedly installed at the top of the sliding block (33). The cleaning mechanism (4) is fixedly installed at the top of the support rod (332).

5. A textile roller cleaning device according to claim 1, characterized in that, The cleaning mechanism (4) includes a ring (41), a bearing disc (42), a rotating ring (43), a third drive assembly, and a cleaning assembly (45). The ring (41) is sleeved on the outside of the first sleeve (13) and coaxially arranged therewith. The ring (41) is fixedly installed on the top of the support rod (332). The bearing disc (42) is fixedly installed on the inner wall of the ring (41). The rotating ring (43) is fixedly installed between the bearing discs (42). The third drive assembly is fixedly installed on the top of the ring (41) and connected to the rotating ring (43). The cleaning assembly (45) is detachably installed inside the rotating ring (43).

6. A textile roller cleaning device according to claim 5, characterized in that, The top of the ring (41) is set as a flat platform, and a notch (411) is provided on the right side of the top of the ring (41). The third drive assembly includes a third motor (441), a gear (442) and a gear ring (443). The gear ring (443) is fixedly sleeved on the outside of the rotating ring (43). The third motor (441) is fixedly installed on the platform at the top of the ring (41). The gear (442) is fixedly installed on the output end of the third motor (441), and the bottom end of the gear (442) passes through the notch (411) and meshes with the top of the gear ring (443).

7. A textile roller cleaning device according to claim 5, characterized in that, The cleaning assembly (45) includes a ring (451), a scraper (452), and a brush (453). An annular inner edge plate (431) is provided on the left side of the inner wall of the rotating ring (43). Third screw holes are provided at both ends of the inner edge plate (431). The ring (451) is placed inside the rotating ring (43) and fits against the inner edge plate (431). Third screws (46) are fixedly installed at both ends of the right side of the ring (451) and inserted into the corresponding third screw holes. The two third screws (46)... Nuts (47) are threaded onto one end of the inner edge plate (431). Multiple scrapers (452) are arranged in a circular array on the right half of the inner wall of the ring body (451). The scrapers (452) are arc-shaped, and the end of the scraper (452) away from the ring body (451) can be in contact with the outer wall of the roller body (5). Multiple brushes (453) are arranged in a circular array on the left half of the inner wall of the ring body (451), and the brushes (453) can contact the outer wall of the roller body (5).

8. A textile roller cleaning device according to claim 1, characterized in that, The bottom of the movable plate (14) is provided with first ball grooves at both ends. Rotatable first ball bearings (144) are provided in both first ball grooves. The parts of the two first ball bearings (144) extending out of the first ball grooves are in contact with the bottom plate (11). The top and bottom corners of the opening (141) are provided with second ball grooves. Rotatable second ball bearings (145) are provided in each second ball groove. The parts of each second ball bearing (145) extending out of the second ball groove are in contact with the guide plate (16).

Images