Transfer device

Abstract

The utility model discloses a transfer device, which belongs to the field of plate processing and comprises a support component, a rolling component, a limiting component and universal wheels, the rolling component comprises rollers arranged on the support component, a limiting plate of the limiting component is movably arranged at the top of the support component and has a limiting position and an initial position, and the universal wheels are arranged on the limiting plate. When the limiting plates are located at the limiting positions, the top edges of the limiting plates are located above the top edges of the rolling wheels, and the to-be-transferred objects can be limited and prevented from falling off in the transferring process; when the limiting plates are located at the initial positions, the top edges of the limiting plates are located below the top edges of the rollers or flush with the top edges of the rollers so as to avoid intervening in movement of the to-be-transferred objects, the universal wheels are installed at the bottoms of the supporting assemblies, free steering of the supporting assemblies can be achieved, and use by operators is facilitated.

Description

Technical Field

[0001] The utility model relates to the field of plate processing, in particular to a transfer device. Background Art

[0002] During the processing of the plates, it is necessary to transfer or transport them between different equipment to assist in the production of the plates.

[0003] In the prior art, traditional manual transfer devices are usually used to transfer large-sized thin plate materials. Specifically, the manual transfer device mainly includes a rotating frame and rollers arranged on the top of the transfer frame. The setting of the rollers enables the large-sized thin plate materials to move on the rollers, and the friction type during movement is rolling friction. On the basis of reducing the wear on the large-sized thin plate materials, it is also convenient for loading and unloading the large-sized thin plate materials. However, since the movement of the manual transfer device is usually manually driven and the speed is uneven, the large-sized thin plate materials are more likely to move relative to the rollers during the movement of the manual transfer device, and there is a risk of falling, which leads to the poor stability of the manual transfer device in the prior art when transporting large-sized thin plate materials.

[0004] Therefore, a transfer device is urgently needed to solve the above problems. Utility Model Content

[0005] The utility model aims to provide a transfer device to solve the problem in the prior art that the large-sized thin plate materials have poor stability and are easy to fall when the transfer device transfers the large-sized thin plate materials.

[0006] As conceived above, the technical solution adopted by the utility model is:

[0007] Transfer device, comprising:

[0008] Support components;

[0009] A rolling assembly, comprising a roller disposed on the top of the supporting assembly, the roller being capable of self-rotation;

[0010] A limit assembly, the limit assembly comprising a limit plate and a locking member; the limit plate is movably arranged at the top of the support assembly and has a limit position and an initial position, when the limit plate is located at the limit position, the top edge of the limit plate is located above the top edge of the roller; when the limit plate is located at the initial position, the top edge of the limit plate is located below the top edge of the roller or flush with the top edge of the roller, the locking member is adjustably arranged at the top of the support assembly and can lock the limit plate at the limit position;

[0011] The universal wheel is installed at the bottom of the supporting assembly.

[0012] Furthermore, the limiting assembly further comprises a fixing seat, the fixing seat is arranged on the top of the supporting assembly, and the limiting plate is rotatably connected to the supporting assembly to switch between the limiting position and the initial position;

[0013] The locking member is connected to the fixing seat in an adjustable manner. When the limiting plate is located at the limiting position, the locking member locks the limiting plate on the fixing seat.

[0014] Furthermore, the fixing seat includes a first connecting plate connected to the supporting assembly and a second connecting plate vertically connected to the first connecting plate, the limiting plate is connected to the connecting seat, the second connecting plate and the connecting seat are both provided with through holes, and when the limiting plate is in the limiting position, the locking member is arranged through the through hole on the second connecting plate and the through hole on the connecting seat.

[0015] Furthermore, a buffer pad is provided on the limiting plate, and the buffer pad is used to contact the object to be transported.

[0016] Furthermore, the support assembly includes a plurality of bearing rods spaced apart along its length direction, each of the bearing rods extending along the width direction of the support assembly; each of the bearing rods is provided with a plurality of rollers spaced apart along the width direction of the support assembly.

[0017] Furthermore, the roller is arranged on the bearing rod through a wheel frame, and in the width direction of the support assembly, one end of the wheel frame arranged at the end of the bearing rod is arranged on the bearing rod, and the other end is provided with the roller and inclined toward the outside of the support assembly.

[0018] Furthermore, the transfer device also includes a plurality of lifting mechanisms, which are arranged at intervals along the circumference of the support assembly, the lifting supports of the lifting mechanisms are connected to the support assembly, and the movable ends of the lifting mechanisms are adjustably connected to the lifting supports along the vertical direction so as to be able to lift the support assembly.

[0019] Furthermore, the support assembly is provided with an escape opening on at least one side in the width direction thereof.

[0020] Furthermore, the axes of the plurality of rollers are in the same direction.

[0021] Furthermore, an elastic layer is provided on the outer surface of the roller.

[0022] The transfer device proposed in the utility model comprises a supporting assembly, a rolling assembly, a limiting assembly and a universal wheel. The rolling assembly comprises a roller arranged on the supporting assembly to facilitate the loading and unloading of objects to be transferred. The limiting plate of the limiting assembly is movably arranged on the top of the supporting assembly and has a limiting position and an initial position. When the limiting plate is in the limiting position, the locking member can lock the limiting plate in the limiting position, and the top edge of the limiting plate is located above the top edge of the roller, so as to limit the object to be transferred; when the limiting plate is in the initial position, the top edge of the limiting plate is located below the top edge of the roller or flush with the top edge of the roller to avoid interfering with the movement of the object to be transferred. The object to be transferred is carried by the roller, so that the object to be transferred can move on the supporting assembly. The setting of the limiting assembly can improve the stability of the object to be transferred and prevent the object to be transferred from falling during the transfer process. A freely movable universal wheel is provided at the bottom of the supporting assembly to realize the free steering of the supporting assembly. The vehicle is light and flexible and convenient for operators to use. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the structure of the transfer device provided by the embodiment of the utility model;

[0024] Figure 2 This utility model Figure 1 The enlarged view of point A in the middle;

[0025] Figure 3 This utility model Figure 1 The enlarged view of point B in the middle;

[0026] Figure 4 This utility model Figure 1 Enlarged view of point C in the middle;

[0027] Figure 5 This utility model Figure 1 The enlarged view of point D in the middle;

[0028] Figure 6 This utility model Figure 1 Enlarged view of point E in the middle;

[0029] Figure 7 This utility model Figure 1 Enlarged view of point F in the middle.

[0030] In the figure:

[0031] 1. Support assembly; 2. Rolling assembly; 21. Roller; 211. Elastic layer; 22. Bearing rod; 23. Wheel frame; 3. Limit assembly; 31. Limit plate; 311. Connecting seat; 312. Buffer pad; 32. Fixed seat; 321. First connecting plate; 322. Second connecting plate; 33. Locking piece; 4. Universal wheel; 5. Lifting mechanism; 51. Lifting support; 52. Movable end; 53. Manual rocker; 6. Escape opening; 7. Handle; 8. Hinge. DETAILED DESCRIPTION

[0032] In order to make the technical problems solved by the present invention, the technical solutions adopted and the technical effects achieved clearer, the technical solutions of the present invention are further described below in conjunction with the accompanying drawings and through specific implementation methods. It is understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for the convenience of description, only the parts related to the present invention are shown in the accompanying drawings, rather than all of them.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" 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 a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right", etc., are based on the directions or positions shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] The utility model provides a transfer device to improve the transfer flexibility of objects to be transferred, save time and labor, and facilitate the transfer of objects to be transferred.

[0037] like Figure 1-Figure 7 As shown, the transfer device includes a support assembly 1, a rolling assembly 2, a limiting assembly 3 and a universal wheel 4. Among them, the rolling assembly 2 includes a roller 21 arranged on the top of the support assembly 1, and the roller 21 can rotate by itself. The roller 21 is used to carry the object to be transferred. The limiting assembly 3 can limit the position of the object to be transferred, and the universal wheel 4 is installed at the bottom of the support assembly 1, which is used for the movement of the support assembly 1, thereby improving the transfer flexibility of the object to be transferred.

[0038] In this embodiment, the object to be transported is a large-sized thin plate material. By setting up the transfer device, the stability of the large-sized thin plate material can be improved to prevent the large-sized thin plate material from falling during the transfer process. A freely movable universal wheel 4 is provided at the bottom of the support component 1, which can realize the free steering of the support component 1. It is light and flexible and easy for operators to use.

[0039] Specifically, Figure 2-Figure 3 As shown, the limiting assembly 3 includes a limiting plate 31 and a locking member 33. The limiting plate 31 is movably arranged at the top of the supporting assembly 1 and has a limiting position and an initial position. When the limiting plate 31 is at the limiting position, the top edge of the limiting plate 31 is located above the edge of the top surface of the roller 21 to limit the object to be transferred and prevent the object to be transferred from falling during transportation; when the limiting plate 31 is at the initial position, the top edge of the limiting plate 31 is located below the top edge of the roller 21, or the top edge of the limiting plate 31 is flush with the top edge of the roller 21, thereby releasing the limit of the object to be transferred to avoid interfering with the movement of the object to be transferred. The locking member 33 is adjustably arranged at the top of the supporting assembly 1 and can lock the limiting plate 31 at the limiting position to improve the stability of the limiting plate 31 in limiting the object to be transferred.

[0040] In this embodiment, when the limit plate 31 is in the limit position, the top edge of the limit plate 31 is located above the top edge of the roller 21, which can limit the object to be transferred; when the limit plate 31 is in the initial position, the top edge of the limit plate 31 is located below the top edge of the roller 21 to avoid interfering with the movement of the object to be transferred. The universal wheel 4 is installed at the bottom of the support assembly 1, and the object to be transferred is carried by the roller 21, which facilitates the movement of the object to be transferred on the support assembly 1. The setting of the limit assembly 3 can prevent the object to be transferred from falling during the transportation process. A freely movable universal wheel 4 is provided at the bottom of the support assembly 1, which can realize the free steering of the support assembly 1. It is light and flexible, and is convenient for operators to use.

[0041] Furthermore, if Figure 1 and Figure 6As shown, the top edge of the support assembly 1 may also be provided with a plurality of handles 7, which are arranged at intervals along the circumference of the support assembly 1. Optionally, a handle 7 is provided at each end of the length direction of the support assembly 1 to facilitate pushing and pulling by the operator. For example, the handles 7 are provided with 2, 4, 6, etc.

[0042] In some optional embodiments, the support assembly 1 can be composed of multiple support rods connected by connecting parts, and the support rods are made of aluminum profiles, so that the weight of the entire support assembly 1 is lighter, thereby improving the portability of the transfer device and facilitating pushing.

[0043] Alternatively, if Figure 2 As shown, the limit assembly 3 also includes a fixed seat 32, which is arranged on the support assembly 1, and the limit plate 31 is rotatably connected to the support assembly 1, so that the limit plate 31 can be rotated from the initial position to the limit position, and from the limit position to the initial position, so as to realize the conversion between the limit position and the initial position. The locking member 33 is adjustably connected to the fixed seat 32, and is used to lock the limit plate 31 on the fixed seat 32, so that the limit plate 31 is kept in the limit position.

[0044] Specifically, when the limit plate 31 switches from the limit position to the initial position, the locking member 33 releases the lock on the limit plate 31, and the edge of the limit plate 31 facing away from the support assembly 1 rotates from above the edge of the roller 21 facing away from the support assembly 1 to below the edge of the roller 21 facing away from the support assembly 1 or is flush with the edge of the roller 21 facing away from the support assembly 1, and then is in the initial position. Similarly, when the limit plate 31 switches from the initial position to the limit position, the edge of the limit plate 31 facing away from the support assembly 1 rotates from below the edge of the roller 21 facing away from the support assembly 1 to above the edge of the roller 21 facing away from the support assembly 1, and the limit plate 31 is locked by the locking member 33, so that the limit plate 31 remains in the limit position.

[0045] Furthermore, if Figure 3 As shown, the limit plate 31 is rotatably connected to the support assembly 1 through the hinge 8, and the hinge 8 is fixedly connected to the support assembly 1. Specifically, one blade of the hinge 8 is fixed to the support assembly 1, and the limit plate 31 is fixed to the other blade of the hinge 8. Furthermore, the hinge 8 is installed on the edge of the support assembly 1 away from the fixed seat 32, so as to facilitate the movement of the limit plate 31 when the state is switched. Of course, it can be understood that the limit plate 31 can also be rotatably connected to the support assembly 1 through other structures, and this embodiment is not limited to this.

[0046] In this embodiment, if Figure 2As shown, the fixing seat 32 includes a first connecting plate 321 connected to the supporting assembly 1 and a second connecting plate 322 vertically connected to the first connecting plate 321. The limiting plate 31 is connected to the connecting seat 311, and the second connecting plate 322 and the connecting seat 311 are both provided with through holes. When the limiting plate 31 is in the limiting position, the locking member 33 is arranged through the through hole on the second connecting plate 322 and the through hole on the connecting seat 311. For example, the end of the locking member 33 is located in the through hole of the connecting seat 311, that is, the locking member 33 does not pass through the connecting seat 311 to avoid interference with the object to be transported.

[0047] Specifically, the locking piece 33 is a bolt that can move axially along the through hole of the second connecting plate 322. When the limiting plate 31 is in the limiting position, the bolt is simultaneously located in the through hole of the second connecting plate 322 and the through hole of the connecting seat 311 through the axial movement of the bolt, thereby fixing the limiting plate 31 on the fixing seat 32.

[0048] In order to reduce the damage of the limiting component 3 to the object to be transported, Figure 2 As shown, a buffer pad 312 is provided on the limiting plate 31, and the buffer pad 312 is used to contact the object to be transported. In this embodiment, the buffer pad 312 is arranged on the side close to the roller 21 when the limiting plate 31 is in the limiting position. For example, when the limiting plate 31 is in the limiting position, the limiting plate 31 is perpendicular to the support assembly 1, so that the limiting plate 31 with the buffer pad 312 can face the object to be transported, thereby improving the limiting effect and avoiding the situation where the object to be transported is easily displaced due to the tilt of the limiting plate 31. For example, the buffer pad 312 can be a silicone pad, a rubber pad or other elastic structure, which is not limited in this embodiment.

[0049] Furthermore, in order to improve the overall limiting effect of the transfer device, a plurality of limiting components 3 are provided, and the plurality of limiting components 3 are circumferentially spaced and arranged on the support component 1. For example, the number of limiting components 3 is 2, 4, 6, 8, etc.

[0050] Alternatively, if Figure 4 As shown, the support assembly 1 includes a plurality of bearing rods 22 arranged at intervals along the length direction thereof, each bearing rod 22 extends along the width direction of the support assembly 1, and a plurality of rollers 21 are arranged on each bearing rod 22, and the plurality of rollers 21 are evenly and spaced apart along the width direction of the support assembly 1, and the plurality of rollers 21 are evenly arranged above the plurality of bearing rods 22. It can be understood that by supporting the rollers 21 with a plurality of bearing rods 22, the arrangement of the supporting plane is reduced, which is conducive to the lightweighting of the transfer device.

[0051] Furthermore, the support assembly 1 also includes a support frame, a plurality of bearing rods 22 are detachably connected to the support frame, and a plurality of rollers 21 are detachably connected to the bearing rods 22. The user can appropriately adjust the positions and quantities of the bearing rods 22 and rollers 21 according to the weight and volume of the object to be transported, so as to improve the supporting effect of the object to be transported. At the same time, when a bearing rod 22 is deformed and / or a roller 21 is damaged, they can be replaced separately, which is more economical.

[0052] Alternatively, if Figure 4 As shown, the roller 21 is arranged on the load-bearing rod 22 through the wheel frame 23. In the width direction of the support assembly 1, one end of the wheel frame 23 arranged at both ends of each load-bearing rod 22 is arranged on the load-bearing rod 22, and the other end is provided with the roller 21 and tilted toward the outside of the support assembly 1. It can be understood that the wheel frame 23 at both ends of the load-bearing rod 22 is tilted toward the outside of the support assembly 1, so that the rollers 21 at both ends are located above or outside the edge of the support assembly 1. When loading and unloading objects to be transported, part of the objects to be transported can be directly abutted against the roller 21, which can achieve a guiding effect and facilitate the overall movement of the objects to be transported to the top of the support assembly 1. In addition, the bearing area is increased, and the stability of carrying the objects to be transported is improved.

[0053] In order to improve the flexibility of the movement of the objects to be transported on the rolling assembly 2 and improve the convenience of loading and unloading the objects to be transported, the axial directions of the multiple rollers 21 are consistent, so that the rotation directions of the rollers 21 are consistent, which facilitates the pushing of heavy objects on the transfer device.

[0054] like Figure 4 As shown, in order to prevent the roller 21 from damaging the object to be transported, an elastic layer 211 is provided on the outer surface of the roller 21. It can be understood that when the object to be transported is located above the roller 21, the elastic layer 211 directly contacts the object to be transported, thereby preventing the roller 21 from damaging the object to be transported. In other embodiments, the roller 21 can also be directly set as an elastic plastic roller, which is not limited here.

[0055] Furthermore, if Figure 1 and Figure 7 As shown, the transfer device further includes a plurality of lifting mechanisms 5, which are arranged at intervals along the circumference of the support assembly 1, and the lifting support 51 of the lifting mechanism 5 is connected to the support assembly 1, and the movable end 52 of the lifting mechanism 5 is adjustably connected to the lifting support 51 along the vertical direction to lift the support assembly 1. For example, the lifting mechanisms 5 are provided with 2, 4, 6, 8, etc.

[0056] It can be understood that the jacking support 51 is connected to the support component 1, and the movable end 52 is connected to the jacking support 51 in an adjustably positionable manner along the vertical direction. When the movable end 52 moves along the vertical direction, it can abut against the support surface where the transfer device is located. During the movement of the movable end 52, the support component 1 can move upward relative to the support surface, thereby realizing the jacking of the support component 1. After the jacking is completed, the support component 1 is in a stable state, and the transfer device can be connected to devices of different heights, thereby improving the convenience of transportation. At the same time, the transferred device after jacking can also be used as a stable temporary operating table.

[0057] Optionally, the lifting mechanism 5 is manually driven, and a manual rocker 53 is provided at one end of the lifting support 51 away from the movable end 52, and the movement of the movable end 52 can be achieved by rotating the manual rocker 53. Of course, in other embodiments, the driving mode can also be set to electric drive.

[0058] Alternatively, if Figure 5 As shown, the support assembly 1 is provided with a clearance opening 6 on at least one side in the width direction thereof, and the clearance opening 6 penetrates the support assembly 1 in the vertical direction. By providing the clearance opening 6, when loading and unloading the objects to be transported, the operator or the operating machine can be located inside the transport device, thereby improving the convenience of the operator in loading and unloading the objects to be transported. In the example, the clearance opening 6 is provided with 1, 2, 4, etc. It should be noted that the top edge of the clearance opening 6 is provided with a roller 21 to ensure the load-bearing effect.

[0059] During operation, the operator first ensures that the limit plate 31 is located at the initial position, that is, the top edge of the limit plate 31 is located below the top edge of the roller 21 or is flush with the top edge of the roller 21, so as to prevent the limit plate 31 from affecting the loading of the large-sized thin plate material. Then, the large-sized thin plate material is loaded on the top surface of the support assembly 1 along the length direction of the load-bearing rod 22, and then the limit plate 31 is rotated to the limit position, and the limit plate 31 is locked in the limit position using the locking member 33, that is, the top edge of the limit plate 31 is located above the top edge of the roller 21, so as to limit the large-sized thin plate material. Then, the worker operates the transfer device to transfer the large-sized thin plate material to the preset position. After reaching the preset position, the locking member 33 is released from the limit plate 31 and rotated to the initial position to prevent the limit plate 31 from affecting the unloading of the large-sized thin plate material. Then, the operator can unload the large-sized thin plate material along the length direction of the load-bearing rod 22.

[0060] The above embodiments are only to illustrate the basic principles and characteristics of the present invention. The present invention is not limited by the above embodiments. Without departing from the spirit and scope of the present invention, the present invention may be subject to various changes and modifications, which are within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A transfer device, characterized in that: include: Support assembly (1); A rolling assembly (2), comprising a roller (21) arranged on the top of the supporting assembly (1), wherein the roller (21) is capable of self-rotation; A limit assembly (3), the limit assembly (3) comprising a limit plate (31) and a locking member (33); the limit plate (31) is movably arranged at the top of the support assembly (1), and has a limit position and an initial position; when the limit plate (31) is located at the limit position, the top edge of the limit plate (31) is located above the top edge of the roller (21); when the limit plate (31) is located at the initial position, the top edge of the limit plate (31) is located below the top edge of the roller (21) or is flush with the top edge of the roller (21); the locking member (33) is adjustably arranged at the top of the support assembly (1), and can lock the limit plate (31) at the limit position; A universal wheel (4) is installed at the bottom of the support assembly (1).

2. The transfer device according to claim 1, characterized in that: The limiting assembly (3) further comprises a fixing seat (32), wherein the fixing seat (32) is arranged on the top of the supporting assembly (1), and the limiting plate (31) is rotatably connected to the supporting assembly (1) to switch between the limiting position and the initial position; The locking member (33) is connected to the fixing seat (32) in an adjustable manner; when the limiting plate (31) is located at the limiting position, the locking member (33) locks the limiting plate (31) on the fixing seat (32).

3. The transfer device according to claim 2, characterized in that: The fixing seat (32) comprises a first connecting plate (321) connected to the supporting assembly (1) and a second connecting plate (322) vertically connected to the first connecting plate (321); the limiting plate (31) is connected to a connecting seat (311); the second connecting plate (322) and the connecting seat (311) are both provided with through holes; when the limiting plate (31) is in the limiting position, the locking member (33) is arranged to pass through the through hole on the second connecting plate (322) and the through hole on the connecting seat (311).

4. The transfer device according to claim 1, characterized in that: The limiting plate (31) is provided with a buffer pad (312), and the buffer pad (312) is used to contact the object to be transported.

5. The transfer device according to claim 1, characterized in that: The support assembly (1) comprises a plurality of bearing rods (22) arranged at intervals along its length direction, each of the bearing rods (22) extending along the width direction of the support assembly (1); each of the bearing rods (22) is provided with a plurality of rollers (21) arranged at intervals along the width direction of the support assembly (1).

6. The transfer device according to claim 5, characterized in that: The roller (21) is arranged on the bearing rod (22) via a wheel frame (23); in the width direction of the support assembly (1), one end of the wheel frame (23) arranged at the end of the bearing rod (22) is arranged on the bearing rod (22), and the other end is provided with the roller (21) and is inclined toward the outside of the support assembly (1).

7. The transfer device according to any one of claims 1 to 6, characterized in that: The transfer device also includes a plurality of lifting mechanisms (5), which are arranged at intervals along the circumference of the support assembly (1), and the lifting support (51) of the lifting mechanism (5) is connected to the support assembly (1), and the movable end (52) of the lifting mechanism (5) is connected to the lifting support (51) in an adjustable manner in the vertical direction so as to be able to lift the support assembly (1).

8. The transfer device according to any one of claims 1 to 6, characterized in that: The support assembly (1) is provided with an escape opening (6) on at least one side in the width direction thereof.

9. The transfer device according to any one of claims 1 to 6, characterized in that: The axial directions of the plurality of rollers (21) are consistent.

10. The transfer device according to any one of claims 1 to 6, characterized in that: The outer surface of the roller (21) is provided with an elastic layer (211).

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