A bead screening mechanism and bead feeding device

Abstract

The utility model provides a kind of pearl screening mechanism, including the receiving groove for accommodating pearl being arranged on mounting seat, the receiving groove bottom is equipped with carousel and carousel drive structure, the edge of carousel is equipped with at least one pearl pushing block for pushing pearl, the sidewall of receiving groove is equipped with at least one selected pearl hole for screening pearl, so that qualified pearl can enter under the action of gravity or / and the pushing of pearl pushing block. The screening of pearl can be realized, and the efficiency is high, without manual operation, which is beneficial to subsequent embroidery.

Description

Technical Field

[0001] This utility model relates to the field of bead embroidery technology, and in particular to a bead screening mechanism and a bead feeding device. Background Technology

[0002] The beading mechanism in bead embroidery generally includes a tube for holding beads, a feed container at the top of the tube, and a guide rod inserted into the tube at one end. The feed container supplies beads into the tube, and the rotation of the tube or propeller moves the beads, with a certain probability guiding the flowing beads to the beading end of the guide rod. The beading method described above is only applicable to regular beads. These beads do not require distinguishing between the front and back when sewing, so they can be used normally regardless of which end is inserted into the guide rod.

[0003] However, for some irregular beads, especially those beads that require strict distinction between the front and back during embroidery, there is an urgent need to set up a mechanism to screen the beads and ensure that the beads inserted by the guide rod are facing the same direction so as not to affect the embroidery effect. Utility Model Content

[0004] To address the problems of the prior art, this utility model provides a bead screening mechanism and a bead feeding device, which can screen beads, especially distinguish between beads with opposite sides, and transport qualified beads to the bead guide rod to complete the stringing process. It has high screening efficiency and good sewing effect.

[0005] The technical solution adopted is as follows: A bead sorting mechanism includes a receiving groove for holding beads, which is inclinedly arranged on a mounting base. The bottom of the receiving groove is provided with a turntable and a turntable driving structure. The edge of the turntable is provided with at least one bead pushing block for pushing beads. The side wall of the receiving groove is provided with at least one bead sorting hole for sorting beads, so that qualified beads can enter under the action of gravity and / or the pushing of the bead pushing block.

[0006] Furthermore, the bead selection hole is provided in multiple locations, each corresponding to a conveying groove, and the multiple conveying grooves are ultimately connected to the same conveying channel. The bead selection hole is located on the lower side wall of the receiving groove; the bead selection hole is located at the bottom of the side wall.

[0007] Furthermore, the receiving groove and the turntable are circular, and several pusher blocks are arranged along the circumference of the turntable.

[0008] Furthermore, the turntable drive structure includes a turntable drive motor mounted on a mounting base.

[0009] Furthermore, the bead selection hole includes a main bead selection hole located directly below the circular receiving groove and auxiliary bead selection holes not directly below it. The conveying groove includes a main conveying groove located directly below the circular receiving groove and connected to the main bead selection hole, and auxiliary conveying grooves located on one or both sides of the main conveying groove and connected to the corresponding auxiliary bead selection holes. The auxiliary conveying grooves are incorporated into the main conveying groove. A turning wheel is provided at the point where the auxiliary conveying groove and the main conveying groove are incorporated, which can move the beads at the incorporated point. The turning wheel is provided with a second driving structure. The end section of the main conveying groove forms a conveying channel.

[0010] Furthermore, the auxiliary conveying trough is provided with at least two, and the at least two auxiliary conveying troughs are staggered and merged into the main conveying trough. Each merging point is provided with a pawl that can move the beads at the merging point. The second driving structure includes a drive shaft and a pulley assembly connecting the drive shaft and the power source of the turntable driving structure. A transmission gear is provided between the drive shafts of the multiple pawls.

[0011] This utility model also provides a bead feeding device, including a bead screening mechanism, a bead conveying mechanism for transporting beads from the bead screening mechanism to the bead guide rod, and a fixing mechanism provided on one side of the bead guide rod for fixing the bead guide rod, wherein the bead conveying mechanism is provided on the mounting base.

[0012] The bead conveying mechanism includes a conveying trough, a bead conveying channel located at the corresponding position of the conveying trough, a bead dropping hole cooperating with a guide rod on the bottom surface of the conveying trough, a rotatable driving component at the upper end of the conveying trough, a corresponding third driving structure on the driving component, and at least one limiting hole on the driving component that can accommodate beads and push the beads to rotate within the conveying trough. The bottom surface of the conveying trough has a smooth sliding surface or several sliding surfaces connected in sequence between the conveying channel and the bead dropping hole, allowing the beads to slide. The sliding surface has an inclined angle at the point where it cooperates with the conveying channel to receive the beads output from the inclined channel. The inclined angle of the sliding surface gradually decreases to a plane from the corresponding point of the conveying channel to the bead dropping hole. At least before the beads enter the bead dropping hole, the sliding surface is a plane. The bead dropping hole and the conveying channel are located at different work positions.

[0013] Furthermore, the driving component has several limiting holes arranged circumferentially, each limiting hole can accommodate one bead; the limiting holes are provided with limiting surfaces on their inner sides, and the distance between the limiting surfaces and the sidewall of the conveying bottom groove is adapted to the diameter of the conveyed bead.

[0014] Furthermore, the end face of the drive component that mates with the sliding surface is provided with an inclined surface that mates with the sliding surface.

[0015] Furthermore, the conveying channel is inclined at the upper end of the conveying trough, and the inclination angle of the conveying channel is greater than or equal to the inclination angle of the sliding surface near the conveying channel.

[0016] Furthermore, the conveying bottom groove is provided with a climbing sliding surface that connects with the sliding surface from the drop hole to the point where it cooperates with the conveying channel. The climbing sliding surface is located on the path of the drop hole as it rotates with the drive component. The climbing sliding surface is a smooth sliding surface or several sliding surfaces that are connected in sequence to allow the beads to slide.

[0017] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention provides a bead sorting mechanism, including an inclined bead receiving groove, a turntable at the bottom of the groove to rotate the beads, bead selection holes on the side wall of the groove, and bead pushing blocks on the edge of the turntable for pushing the beads. Qualified beads, randomly placed and conforming to the sorting direction of the bead selection holes, can enter the selection holes under the drive of gravity and / or the bead pushing blocks, thus completing the bead sorting. The bead pushing blocks improve the sorting efficiency. This invention enables rapid bead sorting, ensures bead consistency, and improves the efficiency of bead threading and subsequent sewing. This invention also provides a bead feeding device, including a bead conveying mechanism that transports the beads sorted by the bead sorting mechanism to a bead guide rod. This integrated design enables bead sorting and threading, ensuring the quality of the sewing. Attached Figure Description

[0018] Figure 1 , 7 This is a schematic diagram of the overall structure of the bead feeding device at two different angles; Figure 2 This is a top view of the present invention; Figure 3 This is an enlarged view of part of the bead conveying mechanism; Figure 4 This is a partial structural diagram; Figure 5 , 6 Schematic diagrams of dual conveyor troughs at different angles; Figure 8 A perspective structural diagram of a multi-conveyor channel implementation case; Figure 9 This is an exploded 3D diagram of multiple conveyor channels; Figure 10 for Figure 9 An enlarged schematic diagram of point a; Figure 11 A frontal perspective structural diagram of a multi-conveyor channel implementation case.

[0019] The components include: 1. Receiving groove; 2. Turntable; 3. Bead pushing block; 4. Bead selection hole; 41. Main bead selection hole; 42. Auxiliary bead selection hole; 5. Conveying groove; 51. Main conveying groove; 52. Auxiliary conveying groove; 53. Actuating wheel; 54. Transmission gear; 6. Conveying channel; 7. Mounting base; 8. Bead conveying mechanism; 9. Fixing mechanism; 10. Guide rod; 11. Conveying bottom groove; 12. Bead; 13. Dropping hole; 14. Driving component; 15. Limiting hole; 16. Sliding surface; 17. Limiting surface; 18. Inclined surface; 19. Turntable driving structure; 20. Driving surface; 21. Third driving structure; 21. Driving motor; 2101. Mounting bracket; 2102. Groove; 22. Climbing sliding surface; 161. Detailed Implementation

[0020] The present invention will be further described below with reference to specific embodiments.

[0021] refer to Figure 1-11 A bead sorting mechanism includes a receiving groove 1 inclinedly mounted on a mounting base 7 for accommodating beads. A turntable 2 and a turntable drive structure 19 are provided at the bottom of the receiving groove 1. At least one bead-pushing block 3 is provided on the edge of the turntable 2 for pushing beads. At least one bead-selecting hole 4 is provided on the side wall of the receiving groove 1 for sorting beads 12, allowing qualified beads to enter under gravity and / or the pushing of the bead-pushing block. In this invention, each bead is a bead with two different shapes on its two sides, whose placement direction can be set by the bead-selecting hole 4.

[0022] Because the receiving tank 1 is inclined, most of the beads will concentrate on the lower side wall of the receiving tank 1, preferably at the bottom of the side wall, to increase the probability of bead selection. To ensure that the beads fall into the selection hole 4 under the action of gravity, the selection hole 4 is preferably located on the lower side wall of the receiving tank 1. The beads 12 are placed in the receiving tank 1 and rotate under the drive of the turntable 2. The qualified beads 12 piled up at the selection hole 4 are in line with the shape of the selection hole 4 and have a certain probability of falling into the selection hole 4 under the action of gravity. The turntable 2 drives the beads to rotate. When the bead pusher 3 rotates to the corresponding position of the selection hole 4, if a qualified bead is located at the selection hole 4, the bead pusher 3 will push the qualified bead into the selection hole 4 when it rotates past the selection hole 4; if an unqualified bead is located at the selection hole 4, the bead pusher 3 will rotate and drive the bead away from the selection hole 4, and new beads will fill and fall into the selection hole 4. As the turntable continues to rotate, most of the qualified beads are driven into the selection holes by gravity and / or by the bead-pushing blocks, thus achieving bead selection.

[0023] Preferably, multiple bead-selecting holes 4 are provided, each corresponding to a conveying groove 5, and the multiple conveying grooves 5 are ultimately connected to the same conveying channel 6. The conveying grooves 5 can be made of rigid or flexible material, making the beads fall more smoothly. Providing multiple bead-selecting holes 4 can improve efficiency, allowing multiple beads to enter the selection holes simultaneously and then pass through the conveying grooves 5 into the same conveying channel 6. For example... Figure 5 , 6 It uses two conveyor troughs. Figure 8-11 It uses 3 conveyor channels.

[0024] As an implementation case, see Figure 8-11 The bead selection hole 4 includes a main bead selection hole 41 located directly below the circular receiving groove 1 and auxiliary bead selection holes 42 located not directly below. The conveying groove 5 includes a main conveying groove 51 located directly below the circular receiving groove 1 and connected to the main bead selection hole 41, and auxiliary conveying grooves 52 located on one or both sides of the main conveying groove 51 and connected to the corresponding auxiliary bead selection holes. The auxiliary conveying grooves 52 are incorporated into the main conveying groove 51. A deflecting wheel 53 is provided at the point where the auxiliary conveying groove 52 and the main conveying groove 51 are incorporated, which can move the beads at the incorporated point. The deflecting wheel 53 is provided with a second driving structure. The end section of the main conveying groove 51 forms the conveying channel 6. The main bead selection hole 41 and the main conveying groove 51 are located directly below the receiving groove 1, so their conveying efficiency is high. The auxiliary bead selection hole 42 and the conveying groove 52 are located not directly below, so they can play an auxiliary role and serve as alternatives for directional bead selection. When the beads in the auxiliary conveying trough 52 collide with the beads in the main conveying trough 51 at the point of convergence, to prevent the beads from getting stuck, the rotating actuating wheel 53, which is kept in a constantly rotating state, rotates to move the beads at the point of convergence. This allows the beads to move upwards and re-enter the conveying channel 6, effectively preventing beads coming from the auxiliary conveying trough 52 and the main conveying trough 51 simultaneously from getting stuck at the point of convergence. The beads in the auxiliary conveying trough 52 can be moved first, such as... Figure 11 The left-hand actuating wheel 53 rotates counterclockwise, and the right-hand actuating wheel 53 rotates clockwise. The protrusion on the actuating wheel 53 prioritizes the movement of the beads in the auxiliary conveying grooves 52 on both sides, ensuring that the beads in the main conveying groove 51 pass through smoothly.

[0025] The auxiliary conveying troughs 52 can be set as needed. In this embodiment, at least two are provided. At least two auxiliary conveying troughs 52 are staggered and merged into the main conveying trough 51. Each merging point is provided with a turning wheel 53 that can move the beads at the merging point. The second drive structure includes a drive shaft and a pulley assembly connecting the drive shaft and the power source of the turntable drive structure 19. A transmission gear 54 is provided between the drive shafts of the multiple turning wheels 53. The second drive structure shares the drive motor of the turntable drive structure 19.

[0026] The receiving groove 1 and the turntable 2 are circular, and several ball-pushing blocks 3 are arranged along the circumference of the turntable. By setting multiple ball-pushing blocks 3, the frequency of the ball-pushing blocks 3 passing through the ball-selection hole 4 increases, thus increasing the efficiency of ball pushing.

[0027] The turntable drive structure 19 includes a turntable drive motor mounted on a mounting base. The output shaft of the turntable drive motor is directly connected to the turntable 2, and can directly drive the turntable 2 to rotate.

[0028] Preferably, the inclination angle of the receiving groove 1 can be set to a suitable angle as needed, such as 45 degrees. Other inclination angles can also be selected for the receiving groove 1.

[0029] This utility model also provides a bead feeding device, including the bead screening mechanism described above, a bead conveying mechanism 8 that transports beads from the bead screening mechanism to the bead guide rod 10, and a fixing mechanism 9 located on one side of the bead guide rod 10 for fixing the bead guide rod. The bead conveying mechanism 8 is mounted on the mounting base 7. The bead guide rod 10 can be equipped with an independent positioning structure, such as using multiple time-division opening bead clamps to hold and position the bead guide rod 10. The bead clamp driving structure opens the bead clamps time-division so that the beads oriented through the upper end of the bead guide rod 10 can fall layer by layer as the clamps open, and finally be fed to the embroidery station.

[0030] The bead conveying mechanism 8 includes a conveying trough 11, and a bead conveying channel 6 is located at the corresponding position of the conveying trough 11. The bottom surface of the conveying trough 11 has a drop hole 13 that cooperates with the guide rod 10. The upper end of the conveying trough 11 is provided with a rotatable driving component 14 and a corresponding third driving structure 21. The driving component 14 has at least one limiting hole 15 that can accommodate beads and push the beads to rotate within the conveying trough 11. The bottom surface of the conveying trough 11 extends from the conveying channel 6 to the drop hole. A smooth sliding surface 16 or several sequentially connected sliding surfaces 16 for the sliding of beads are provided between the 13. The sliding surface 16, located at the point of cooperation with the conveying channel 6, has an inclined angle to receive the beads output from the inclined channel. The inclined angle of the sliding surface 16 gradually decreases to a plane from the corresponding point of the conveying channel 6 to the bead drop hole 13. It can be transformed in advance or smoothly transformed into a plane. The sliding surface should be a plane at least before the beads enter the bead drop hole 13. The bead drop hole 13 and the conveying channel 6 are not in the same working position. Preferably, in order to facilitate bead threading, the plane can usually be set as a horizontal plane, but it can also be a plane with a slight inclination. The driving structure 21 includes a driving motor 2101 located at the upper end of the driving member 14 and a mounting bracket 2102 for mounting the driving motor 2101. The output shaft of the driving motor 2101 is directly located at the center of the driving member 14, driving the driving member 14 to rotate.

[0031] The beads fall from the conveying channel 6 into the conveying trough 11 and into the limiting hole 15 of the driving member 14. Each limiting hole 15 can only hold one bead. Preferably, the driving member 14 has several limiting holes 15 arranged circumferentially. The more limiting holes 15 there are, the more beads can be transported, and the higher the efficiency. The sidewall of the limiting hole 15 includes a driving surface 20 and a limiting surface 17. When the driving member 14 rotates, the driving surface 20 of the limiting hole 15 engages with the bead 12, pushing the bead 12 to the drop hole 13. The bead then passes through the drop hole 13 onto the guide rod.

[0032] The conveying trough 11 is further provided with a climbing sliding surface 161 that mates with the sliding surface 16 from the drop hole 13 to the point where it mates with the conveying channel 6. The climbing sliding surface is located on the path of the drop hole 13 as it rotates with the drive member 14. The climbing sliding surface 161 can be a smooth sliding surface or several sliding surfaces connected in sequence for the beads to slide on. If the bead does not fall when it reaches the drop hole 13, the drive member 14 continues to push the bead to rotate. The bead climbs up through the climbing sliding surface 161 to the mating sliding surface 16 and rotates once more before falling again when it passes the drop hole.

[0033] The distance between the limiting surface 17 and the side wall of the conveying groove 11 is adapted to the diameter of the conveyed bead and the corresponding width of the bead on the sliding surface 16 at different inclination angles. The width refers to the width of the projection of the bead onto the bottom surface. The limiting hole 15 is used to limit the bead 12 and drive the bead 12 to slide, so as to ensure that the bead can be accurately passed through the guide rod. Therefore, the limiting hole 15 can not only ensure that the movement and sliding of the bead are unrestricted, but also limit the bead as much as possible so that when the bead reaches the drop hole, the bead hole can be aligned with the guide rod, which is convenient for passing the bead.

[0034] To ensure the bead can smoothly pass through the guide rod, the diameter of the drop hole 13 needs to be greater than or equal to the diameter of the bead. Preferably, the diameter of the drop hole 13 is larger than the diameter of the bead, ensuring that the bead can definitely fall through the drop hole 13. At least before the bead enters the drop hole 13, the sliding surface is flat, keeping the bead horizontal before entering the drop hole, preventing jamming, and allowing the bead to fall into the guide rod 10 under gravity. If the bead 12 enters the drop hole 13 at an angle, the bead hole will be difficult to align with the guide rod, causing jamming.

[0035] The conveying channel 6 is inclined at the upper end of the conveying trough 11, and the inclination angle of the conveying channel 6 is greater than or equal to the inclination angle of the sliding surface 16 near the conveying channel. To ensure that the beads 12 fall smoothly into the sliding surface 16, the inclination angle of the conveying channel 6 must be at least equal to the inclination angle of the sliding surface 16 near the conveying channel, and preferably greater than the inclination angle of the sliding surface 16. If the inclination angle of the sliding surface 16 is too large, the beads are prone to flipping during descent, making it difficult to ensure the correct orientation of the beads and affecting the subsequent sewing effect.

[0036] The end face of the drive member 14 that mates with the sliding surface 16 is provided with an inclined surface 18 that mates with the sliding surface 16 to prevent interference between the drive member 14 and the sliding surface 16.

[0037] Each inclined sliding surface 16 has a corresponding groove 22 at its location on the conveying trough 11 to accommodate the bead and mate with the side wall of the bead. The groove 22 is provided to facilitate the smooth falling of the bead 12 onto the sliding surface. The groove is an arc surface, which provides a certain cushioning effect. The length of the sliding surface needs to be greater than the diameter of the bead; otherwise, the bead will get stuck in the output channel and will not be able to fall. The groove 22 provides a certain depth for the bead, allowing the bead 12 to completely detach from the conveying channel.

[0038] The beads 12 rotate in the receiving groove 1 and pass through the bead selection hole, screening qualified beads into the conveying channel, and then fall from the conveying channel into the bottom conveying groove 11. The driving component drives the beads to the drop hole and thread them onto the guide rod. A fixing structure 9 is also provided on one side of the guide rod, and the fixing structure 9 adopts the existing technology.

[0039] The above description is only an optional embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A bead sorting mechanism, characterized in that: It includes a receiving groove (1) for holding beads, which is inclinedly set on the mounting base (7). The bottom of the receiving groove (1) is provided with a turntable (2) and a turntable drive structure (19). The edge of the turntable (2) is provided with at least one bead pushing block (3) for pushing beads. The side wall of the receiving groove (1) is provided with at least one bead selection hole (4) for screening beads (12) so that qualified beads can enter under the action of gravity and / or the push of the bead pushing block.

2. The bead sorting mechanism as described in claim 1, characterized in that: The bead selection hole (4) is provided in multiple ways, and each bead selection hole (4) corresponds to a conveying groove (5). The multiple conveying grooves (5) are finally connected to the same conveying channel (6). The bead selection hole (4) is located on the side wall of the lower side of the receiving groove (1). The bead selection hole (4) is located at the bottom of the side wall.

3. The bead sorting mechanism as described in claim 1, characterized in that: The turntable drive structure (19) includes a turntable drive motor mounted on the mounting base; the receiving groove (1) and the turntable (2) are circular, and several push ball blocks (3) are arranged along the circumference of the turntable.

4. The bead sorting mechanism as described in claim 2, characterized in that: The bead selection hole (4) includes a main bead selection hole (41) located directly below the circular receiving groove (1) and an auxiliary bead selection hole (42) located not directly below. The conveying groove (5) includes a main conveying groove (51) located directly below the circular receiving groove (1) and connected to the main bead selection hole (41), and an auxiliary conveying groove (52) located on one or both sides of the main conveying groove (51) and connected to the corresponding auxiliary bead selection hole. The auxiliary conveying groove (52) is incorporated into the main conveying groove (51). A pawl (53) is provided at the point where the auxiliary conveying groove (52) and the main conveying groove (51) are incorporated, which can move the beads at the incorporated point. The pawl is provided with a second driving structure. The end section of the main conveying groove (51) forms a conveying channel (6).

5. The bead sorting mechanism as described in claim 4, characterized in that: The auxiliary conveying groove (52) is provided with at least two, and at least two auxiliary conveying grooves (52) are staggered and merged into the main conveying groove (51). Each merging point is provided with a pulsating wheel (53) that can move the beads at the merging point. The second driving structure includes a drive shaft and a pulley assembly that connects the drive shaft and the power source of the turntable drive structure (19). A transmission gear (54) is provided between the drive shafts of the multiple pulsating wheels (53).

6. A bead feeding device, comprising a bead sorting mechanism, a bead conveying mechanism (8) for transporting beads from the bead sorting mechanism to a guide rod (10), and a fixing mechanism (9) disposed on one side of the guide rod (10) for fixing the guide rod, wherein the bead conveying mechanism (8) is disposed on a mounting base (7), characterized in that: The bead sorting mechanism is the bead sorting mechanism according to any one of claims 1-5.

7. The bead feeding device as described in claim 6, characterized in that: The bead conveying mechanism (8) includes a conveying trough (11), a bead conveying channel (6) located at the corresponding position of the conveying trough (11), a bead dropping hole (13) that cooperates with the bead guide rod (10) on the bottom surface of the conveying trough (11), a rotatable driving member (14) at the upper end of the conveying trough (11), a corresponding third driving structure (21) on the driving member (14), and at least one limiting hole (15) on the driving member (14) that can accommodate beads and push beads to rotate in the conveying trough (11). The bottom surface of (11) has a smooth sliding surface (16) or several sliding surfaces (16) connected in sequence between the conveying channel (6) and the drop hole (13). The sliding surface (16) is located at the point where it cooperates with the conveying channel (6) and has an inclined angle to receive the beads output from the inclined channel. The inclined angle of the sliding surface (16) gradually decreases from the corresponding point of the conveying channel (6) to the drop hole (13) to a plane. At least before the beads enter the drop hole (13), the sliding surface is a plane. The drop hole (13) and the conveying channel (6) are not at the same work position.

8. The bead feeding device as described in claim 7, characterized in that: The drive component (14) has several limiting holes (15) arranged circumferentially, each limiting hole (15) can accommodate a bead; the limiting hole (15) is provided with a limiting surface (17) on its inner side, and the distance between the limiting surface (17) and the side wall of the conveying bottom groove (11) is adapted to the diameter of the conveyed bead.

9. The bead feeding device as described in claim 7, characterized in that: The end face of the drive member (14) that mates with the sliding surface (16) is provided with an inclined surface (18) that mates with the sliding surface (16).

10. The bead feeding device as described in claim 7, characterized in that: The conveying channel (6) is inclined at the upper end of the conveying bottom groove (11), and the inclination angle of the conveying channel (6) is greater than or equal to the inclination angle of the sliding surface (16) close to the conveying channel.

11. The bead feeding device as described in claim 7, characterized in that: The conveying bottom groove (11) is provided with a climbing sliding surface (161) that connects with the sliding surface (16) from the drop hole (13) to the part that cooperates with the conveying channel (6). The climbing sliding surface is located on the path of the drop hole (13) rotating with the drive member (14). The climbing sliding surface (161) is a smooth sliding surface or several sliding surfaces connected in sequence for the ball to slide.

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