Polycarbonate plate stacking device

Abstract

The invention relates to the field of plate stacking, in particular to a polycarbonate plate stacking device. According to an existing stacking device, plates cannot be stacked in sequence conveniently, the stacked plates are not neat enough and are prone to inclining or even toppling over, the plates are prone to shaking due to the fact that friction resistance is too large when the stacked plates are transferred, and the surfaces of the plates are prone to being damaged. A polycarbonate plate stacking device comprises a bottom plate and the like. The bottom plate is placed on the ground, a slope is arranged on one side of the bottom plate, two supporting frames are fixedly connected to the side, away from the slope, of the bottom plate, and a plurality of rolling shafts are rotationally connected between the two supporting frames. The positions of the plates are corrected, then the plates are guided and stacked one by one, and finally the plates are pushed out in a unified mode, so that the plates are stacked more conveniently and more orderly after being stacked, and the plates are not prone to inclining or even toppling over.

Description

Technical Field

[0001] The invention relates to the field of plate stacking, and in particular to a polycarbonate plate stacking device. Background Art

[0002] Polycarbonate board, also known as PC board, is a high-performance thermoplastic plastic board, which is widely used in construction, agriculture, industry and other fields. It has very reliable processability and is suitable for designs of various shapes. After the board is produced, each board usually needs to be stacked and stored.

[0003] However, the existing stacking device is not convenient for stacking plates in sequence. The stacked plates are not neat and are prone to tilt or even fall. When the stacked plates are transferred, the plates are prone to shake due to excessive friction resistance, which can also easily cause surface damage to the plates. Summary of the invention

[0004] In order to overcome the shortcomings of the background technology, the present invention provides a polycarbonate sheet stacking device which is easier to stack sheets, stacks them more neatly, reduces transfer resistance, is less likely to cause the stacked sheets to shake, and protects the surface of the sheets.

[0005] The technical solution is: a polycarbonate sheet stacking device, including a base plate, the base plate is placed on the ground, one side of the base plate is provided with an inclined surface, and two support frames are fixedly connected to the side of the base plate away from the inclined surface, and a plurality of rollers are rotatably connected between the two support frames, and the heights of the plurality of rollers decrease successively towards the direction close to the inclined surface on the base plate, and the upper parts of the two support frames are fixedly connected with guide rods, and the side surfaces of the guide rods are trapezoidal structures, a funnel frame is fixedly connected to the middle part of the base plate, a slide rail is fixedly connected to the base plate, and an electric slider is slidably connected to the slide rail, a stacking mechanism is provided on the base plate, the stacking mechanism is in contact with the funnel frame, the stacking mechanism is used to stack a plurality of sheets, a material transfer mechanism is provided on the base plate, the material transfer mechanism is used to transfer the stacked sheets, and an isolation mechanism is provided on the funnel frame, and the isolation mechanism is used to isolate the unloading during material transfer.

[0006] Furthermore, the stacking mechanism includes two columns, both of which are fixedly connected to the base plate, each of which is slidably connected to a sliding frame, a supporting spring is connected between the sliding frame and the column, a stacking plate is fixedly connected between the two sliding frames, a plurality of square holes are opened on the stacking plate, a plurality of bent rods are fixedly connected to the base plate, each of which is slidably connected to a roller, a bent arm is fixedly connected to the electric slider, and a pushing frame is fixedly connected to the end of the bent arm away from the electric slider.

[0007] The cam is provided with two support plates, and the two support plates are provided with six support blocks, and the lower surfaces of the support blocks are in a horizontal state. Three support blocks on the same side form a group, and a swing frame is fixedly connected to each support block, and three swing frames on the same side form a group. A top plate frame is rotatably connected between the three swing frames in each group, and the upper surface of the top plate frame is lower than the upper surface of the support plate frame, and the top plate frame contacts with the support plate frame. Each side of the swing frame is fixedly connected to a moving wheel, and four limit blocks are fixedly connected to the bottom plate, and two limit blocks form a group, and a rack rod is slidably connected between the two limit blocks in each group, and each top plate frame is rotatably connected to a rotating handle on the side away from the supporting frame, and both sides of the rotating handle are fixedly connected to gear 1, and one side of each swing frame is fixedly connected to gear 2, and each gear 2 and the gear 1 are meshed with the rack rod on the same side.

[0008] The cam is connected with the two guide rails at the bottom of the two guide rails, and the guide rails are connected with the two guide rails at the bottom of the two guide rails in a cam manner.

[0009] The cam is provided with two guide wheels, each of which is provided with a plurality of inclined wheels, and a return spring is provided on the sliding wheel. Four limit plates are fixedly connected to the base plate, and each two limit plates form a group, and the two sliding wheels pass through the two groups of limit plates respectively, and a plurality of straight rods are fixedly connected to the base plate, each straight rod is slidably connected to the sliding plate, and a tension spring is connected between the sliding plate and the straight rod, and each two sliding plates form a group, and a pulley is rotatably connected between the two sliding plates in each group, and a cross bar is fixedly connected between each group of sliding plates, and the cross bar contacts with the sliding long rod.

[0010] The beneficial effects of the present invention are as follows: 1. The plate will roll down along the roller into the funnel frame, and the guide rod will correct the position of the plate when it moves on the roller without being skewed. The plate will fall downward from the funnel frame onto the stacking board. Due to gravity, each time a plate falls onto the stacking board, the stacking board and the sliding frame will move downward for a certain distance, and the supporting spring will be compressed, so that each plate is stacked together. The plate pushed out horizontally by the pushing frame will move onto the two supporting plate frames, and then the operator will swing the rotating handle downward to make the rotating handle swing downward 90°, and then the rotating handle swinging downward 90° will drive the gear one to rotate 90°, and the gear one rotating 90° will drive the rack rod to move horizontally, and Drive gear two to rotate 90°, and the rotation of gear two 90° will drive the swing frame and the moving wheel to rotate 90° together, so that the top plate frame originally supported by the support block will be supported by the moving wheel, and after the moving wheel supports the top plate frame, the top plate frame will be lifted up to a certain height, and the upper surface height of the top plate frame will be higher than the upper surface height of the support frame, so that the plate on the support frame can be transferred to the top plate frame, and then the operator drags the rotating handle to drag the plate away along the inclined surface of the bottom plate, by first correcting the position of the plate, then guiding and stacking them one by one, and finally pushing them out uniformly, the stacking of the plates is more convenient, and the stacking is more orderly, and it is not easy to tilt or even tip over.

[0011] 2. When the pushing rack moves horizontally with the electric slider to push the stacked plates out of the stacking plate, the pushed out plates will move to several pulleys. After the electric slider moves a certain distance, the electric slider will contact one end of the sliding long rod and squeeze the sliding long rod to move horizontally for a certain distance. When the sliding long rod moves horizontally for a certain distance, under the guiding action of the inclined protrusion, the tension spring will reset and drive the cross bar, pulley and sliding plate to move downward together, and finally the upper surface of the pulley will be lower than the upper surface of the support frame, and then the plate will fall onto the support frame, and the electric slider will move horizontally and reset. In this way, the bottom of the plate is first lifted up by the pulley, so that the plate will not shake due to resistance when being pushed, and the bottom surface of the plate is protected. Then the pulley is retracted, so that the plate will not slide on the pulley all the time, making the plate more stable after being pushed out. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention.

[0013] Figure 2 For the present invention Figure 1 Schematic diagram of the enlarged three-dimensional structure at point A in the middle.

[0014] Figure 3 It is a three-dimensional structural schematic diagram of the stacking mechanism and the material transfer mechanism of the present invention.

[0015] Figure 4 It is a three-dimensional structural schematic diagram of the inclined plane baffle and the inclined plane block of the present invention.

[0016] Figure 5 It is a partial three-dimensional structural schematic diagram of the isolation mechanism of the present invention.

[0017] Figure 6 It is a partial three-dimensional structural schematic diagram of the material transfer mechanism of the present invention.

[0018] Figure 7 For the present invention Figure 6 Schematic diagram of the enlarged three-dimensional structure at point B in the middle.

[0019] Figure 8 It is a schematic diagram of the separated three-dimensional structure of the support block, the swing frame, the moving wheel and the gear 2 of the present invention.

[0020] Fig. 9 It is a schematic diagram of the three-dimensional structure of the drag reduction mechanism of the present invention.

[0021] Fig.10 It is a schematic diagram of the partial three-dimensional structure of the drag reduction mechanism of the present invention.

[0022] Figure numbers: 1_bottom plate, 21_support frame, 22_roller, 23_guide rod, 3_funnel frame, 41_slide rail, 42_electric slider, 51_column, 52_sliding frame, 53_support spring, 54_stacking plate, 55_bending rod, 56_roller, 57_bending arm, 58_pushing frame, 61_support frame, 62_support block, 63_swing frame, 64_top frame, 65_moving wheel, 66_limiting block, 67_rack rod, 68_turning handle , 69_gear one, 610_gear two, 71_hanging plate, 72_sliding block, 73_reset spring, 74_side rod, 75_swing rod, 76_connecting rod, 77_top block, 78_inclined baffle, 781_inclined block, 79_pressure spring, 710_right angle push rod, 81_guide plate, 82_sliding long rod, 83_return spring, 84_limiting plate, 85_straight rod, 86_sliding plate, 87_tension spring, 88_pulley, 89_cross bar. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0024] Example 1

[0025] A polycarbonate sheet stacking device, such as Figure 1-10 As shown, it includes a base plate 1, which is placed on the ground, and one side of the base plate 1 is provided with an inclined surface. Two support frames 21 are fixedly connected to the side of the base plate 1 away from the inclined surface, and a plurality of rollers 22 are rotatably connected between the two support frames 21. The heights of the plurality of rollers 22 decrease successively toward the direction approaching the inclined surface on the base plate 1. The upper parts of the two support frames 21 are fixedly connected with guide rods 23, and the side surfaces of the guide rods 23 are trapezoidal structures. A funnel frame 3 is fixedly connected to the middle part of the base plate 1, and a slide rail 41 is fixedly connected to the base plate 1. An electric slider 42 is slidably connected to the slide rail 41. A stacking mechanism is provided on the base plate 1, and the stacking mechanism is in contact with the funnel frame 3. The stacking mechanism is used to stack a plurality of plates. A material transfer mechanism is provided on the base plate 1, and the material transfer mechanism is used to transfer the stacked plates. An isolation mechanism is provided on the funnel frame 3, and the isolation mechanism is used to isolate the unloading during material transfer.

[0026] The stacking mechanism includes two columns 51, and the two columns 51 are fixedly connected to the base plate 1. A sliding frame 52 is slidably connected to each of the columns 51. A supporting spring 53 is connected between the sliding frame 52 and the column 51. A stacking plate 54 is fixedly connected between the two sliding frames 52, and a plurality of square holes are opened on the stacking plate 54. A plurality of bent rods 55 are fixedly connected to the base plate 1, and a roller 56 is slidably connected to each of the bent rods 55. A bent arm 57 is fixedly connected to the electric slider 42, and a pushing frame 58 is fixedly connected to the end of the bent arm 57 away from the electric slider 42.

[0027] The material transfer mechanism includes two support plate frames 61, and the two support plate frames 61 are fixedly connected to the bottom plate 1. Six support blocks 62 are placed on the bottom plate 1, and the lower surfaces of the support blocks 62 are in a horizontal state. Three support blocks 62 on the same side form a group, and each support block 62 is fixedly connected to a swing frame 63. The three swing frames 63 on the same side form a group. A top plate frame 64 is rotatably connected between the three swing frames 63 in each group. The upper surface of the top plate frame 64 is lower than the upper surface of the support plate frame 61, and the top plate frame 64 is in contact with the support plate frame 61. A moving wheel 65 is fixedly connected to one side of each swing frame 63, four limit blocks 66 are fixedly connected to the bottom plate 1, two limit blocks 66 form a group, and a rack rod 67 is slidably connected between the two limit blocks 66 in each group, and a rotating handle 68 is rotatably connected to the side of each top plate frame 64 away from the support frame 21, and gear one 69 is fixedly connected to both sides of the rotating handle 68, and a gear two 610 is fixedly connected to one side of each swing frame 63, and each gear two 610 and the gear one 69 are meshed with the rack rod 67 on the same side.

[0028] The isolation mechanism includes four hanging plates 71, and the four hanging plates 71 are fixedly connected to one side of the outer wall of the funnel frame 3. Two hanging plates 71 form a group, and a sliding block 72 is slidably connected between the lower parts of the two hanging plates 71 of each group, and a reset spring 73 is connected between the sliding block 72 and the hanging plates 71. The lower parts of the two hanging plates 71 are fixedly connected to side rods 74, and the lower part of each side rod 74 is rotatably connected to a swing rod 75, and a guide groove is opened on the swing rod 75. The lower part of each sliding block 72 is fixedly connected to a connecting rod 76, and the connecting rod 76 is located on the swing rod 75. In the guide groove, two top blocks 77 are fixedly connected to one side of the stacking plate 54 close to the hanging plate 71, and the two support frames 21 are slidably connected with inclined baffles 78. The lower part of the two inclined baffles 78 close to one end of the stacking plate 54 is fixedly connected with an inclined block 781. The sliding block 72 is used to clamp the inclined block 781 after horizontal movement. A pressure spring 79 is connected between the inclined baffle 78 and the support frame 21. Two right-angle push rods 710 are fixedly connected to one side of the pushing frame 58 close to the electric slider 42, and the right-angle push rods 710 are in contact with one end of the inclined baffle 78.

[0029] In actual work, after the polycarbonate sheets are produced on the production line and conveyed by the conveyor belt, the stacking work continues. After each produced sheet is conveyed by the conveyor belt, it falls onto the roller 22 at a certain interval. As the heights of the rollers 22 decrease successively, the sheets will roll down along the rollers 22 into the funnel frame 3. The guide rods 23 will correct the position of the sheets when moving on the rollers 22, and they will not be skewed. The sheets fall downward from the funnel frame 3 onto the stacking plate 54. Due to gravity, each time a sheet falls onto the stacking plate 54, the stacking plate 54 and the sliding frame 52 will move downward for a distance, and the supporting spring 53 will be compressed, so that each sheet is stacked together. When the number of sheets falling onto the stacking plate 54 gradually increases, and The sliding frame 52 moves downward to the lowest point, the sliding frame 52 contacts the bottom plate 1, and the upper surface of the stacking plate 54 is flush with the lower surface of the pushing frame 58, the roller 56 is located in the square hole on the stacking plate 54, and the upper surface of the roller 56 is higher than the upper surface of the stacking plate 54, so when the stacking plate 54 moves downward to the lowest point, the plates on the stacking plate 54 will contact a plurality of rollers 56, and then the electric slider 42 is started, and then the electric slider 42 will drive the bent arm 57 and the pushing frame 58 to move horizontally together, and the pushing frame 58 will push out the stacked plates on the roller 56, and the pushing frame 58 will always contact the stacking plate 54, so that the stacking plate 54 will not rebound upward, and the plates will be pushed horizontally to the two support frames 61, and the pushing frame 58 will bring The movable inclined plane baffle 78 and inclined plane block 781 move together, the pressure spring 79 is compressed, and then the inclined plane baffle 78 and inclined plane block 781 will squeeze the sliding card block 72 to move downward for a distance, the reset spring 73 is compressed, the inclined plane baffle 78 and inclined plane block 781 continue to move horizontally, so that the sliding card block 72 resets upward and clamps the inclined plane block 781, so that the inclined plane baffle 78 cannot be reset and blocks the plates falling into the funnel frame 3. When the electric slide block 42 drives the pushing rack 58 to push out the stacked plates, the electric slide block 42 will drive the pushing rack 58 to reset together. After the reset is completed, the pushing rack 58 is out of contact with the stacking plate 54, and then the support spring 53 is reset, driving the stacking plate 54 to reset upward. The upward reset of the stacking plate 54 will drive the top block 77 to move upward together. The upper block 77 moves upward, which squeezes the swing rod 75 and causes the end of the swing rod 75 away from the connecting rod 76 to swing upward, thus causing the end of the swing rod 75 close to the connecting rod 76 to swing downward, and drives the sliding block 72 to move downward, so that the sliding block 72 no longer blocks the inclined block 781 and the inclined baffle 78, and then the pressure spring 79 is reset, driving the inclined baffle 78 to reset, and the plate blocked by the inclined baffle 78 falls downward onto the stacking plate 54, and then the plate previously pushed out horizontally by the pushing rack 58 will move to the two support racks 61, and then the operator swings the rotating handle 68 downward, causing the rotating handle 68 to swing downward 90°, and then the rotating handle 68 swinging downward 90° will drive the gear 1 69 to rotate 90°.The rotation of gear 1 69 by 90° will drive the rack rod 67 to move horizontally, and drive gear 2 610 to rotate 90° together. The rotation of gear 2 610 by 90° will drive the swing frame 63 and the moving wheel 65 to rotate 90° together. In this way, the top plate frame 64, which was originally supported by the support block 62, becomes supported by the moving wheel 65. After the moving wheel 65 supports the top plate frame 64, the top plate frame 64 is lifted upward to a certain height, and the height of the upper surface of the top plate frame 64 is higher than the height of the upper surface of the support plate frame 61. In this way, the plate on the support plate frame 61 can be transferred to the top plate frame 64, and then the operator drags the rotating handle 68 to drag the plate away along the inclined surface of the bottom plate 1. By first correcting the position of the plate, then guiding and stacking them one by one, and finally pushing them out uniformly, the stacking of the plates is more convenient, and the stacking is more orderly, and it is not easy to tilt or even tip over.

[0030] Example 2

[0031] On the basis of Example 1, Fig. 9 and Fig.10 As shown, it also includes a drag reduction mechanism, which is arranged on the bottom plate 1. The drag reduction mechanism is used to reduce the resistance of the plate when the stacked plate is transferred. The drag reduction mechanism includes two guide plates 81, each of which is slidably connected to a sliding long rod 82, and the sliding long rod 82 is provided with a plurality of inclined protrusions. A return spring 83 is connected between the sliding long rod 82 and the guide plate 81. Four limit plates 84 are fixedly connected to the bottom plate 1, and each two limit plates 84 form a group. Two sliding long rods 82 passes through two groups of the limit plates 84 respectively, and a plurality of straight rods 85 are fixedly connected to the bottom plate 1, and each of the straight rods 85 is slidably connected to a sliding plate 86, and a tension spring 87 is connected between the sliding plate 86 and the straight rod 85. Each two sliding plates 86 form a group, and a pulley 88 is rotatably connected between the two sliding plates 86 in each group. The pulley 88 is used to lift the plate to reduce the resistance during the movement of the plate. A cross bar 89 is fixedly connected between each group of sliding plates 86, and the cross bar 89 is in contact with the sliding long rod 82.

[0032] Initially, the tension spring 87 is in a stretched state, and the upper surfaces of all the pulleys 88 are higher than the upper surface of the support frame 61, and the upper surface of the pulley 88 is flush with the upper surface of the roller 56. When the push frame 58 moves horizontally with the electric slider 42 to push the stacked plates out of the stacking plate 54, the pushed plates will move to several pulleys 88. When the electric slider 42 moves a certain distance, the electric slider 42 will contact one end of the sliding rod 82 and squeeze the sliding rod 82 to move horizontally for a certain distance. The sliding rod 82 moves horizontally for a certain distance and Under the guiding action of the inclined protrusion, the tension spring 87 is reset to drive the cross bar 89, pulley 88 and sliding plate 86 to move downward together, and finally the upper surface of the pulley 88 is lower than the upper surface of the support frame 61, and then the plate falls onto the support frame 61, and the electric slider 42 moves horizontally and resets. In this way, the bottom of the plate is first lifted by the pulley 88, so that the plate will not shake due to resistance when being pushed, and the bottom surface of the plate is protected. Then the pulley 88 is retracted, so that the plate will not slide on the pulley 88 all the time, making the plate more stable after being pushed out.

[0033] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A polycarbonate sheet stacking device, characterized in that: The invention comprises a bottom plate (1), the bottom plate (1) being placed on the ground, a slope being arranged on one side of the bottom plate (1), two support frames (21) being fixedly connected to the side of the bottom plate (1) away from the slope, a plurality of rollers (22) being rotatably connected between the two support frames (21), the heights of the plurality of rollers (22) decreasing in sequence towards the direction approaching the slope on the bottom plate (1), a guide rod (23) being fixedly connected to the upper parts of the two support frames (21), the side of the guide rod (23) being a trapezoidal structure, and the bottom plate (1) A funnel frame (3) is fixedly connected to the middle part, a slide rail (41) is fixedly connected to the bottom plate (1), an electric slider (42) is slidably connected to the slide rail (41), a stacking mechanism is arranged on the bottom plate (1), the stacking mechanism is in contact with the funnel frame (3), the stacking mechanism is used to stack a plurality of plates, a material transfer mechanism is arranged on the bottom plate (1), the material transfer mechanism is used to transfer the stacked plates, and an isolation mechanism is arranged on the funnel frame (3), the isolation mechanism is used to isolate the unloaded materials during material transfer.

2. A polycarbonate sheet stacking device according to claim 1, characterized in that: The stacking mechanism comprises two columns (51), the two columns (51) are fixedly connected to the bottom plate (1), each column (51) is slidably connected to a sliding frame (52), a supporting spring (53) is connected between the sliding frame (52) and the column (51), a stacking plate (54) is fixedly connected between the two sliding frames (52), the stacking plate (54) is provided with a plurality of square holes, a plurality of bent rods (55) are fixedly connected to the bottom plate (1), each bent rod (55) is slidably connected to a roller (56), a bent arm (57) is fixedly connected to the electric slider (42), and a pushing frame (58) is fixedly connected to one end of the bent arm (57) away from the electric slider (42).

3. A polycarbonate sheet stacking device according to claim 2, characterized in that: The material transfer mechanism comprises two support plate frames (61), the two support plate frames (61) are fixedly connected to the bottom plate (1), six support blocks (62) are placed on the bottom plate (1), the lower surface of the support block (62) is in a horizontal state, three support blocks (62) on the same side form a group, each support block (62) is fixedly connected to a swing frame (63), three swing frames (63) on the same side form a group, and a top plate frame (64) is rotatably connected between the three swing frames (63) in each group, the upper surface of the top plate frame (64) is lower than the upper surface of the support plate frame (61), and the top plate frame (64) is in contact with the support plate frame (61), each One side of the swing frame (63) is fixedly connected with a moving wheel (65), and four limit blocks (66) are fixedly connected to the bottom plate (1), two limit blocks (66) form a group, and a rack rod (67) is slidably connected between the two limit blocks (66) in each group, and each top plate frame (64) is rotatably connected with a rotating handle (68) on the side away from the support frame (21), and both sides of the rotating handle (68) are fixedly connected with a gear 1 (69), and one side of each swing frame (63) is fixedly connected with a gear 2 (610), and each of the gear 2 (610) and the gear 1 (69) is meshed with the rack rod (67) on the same side.

4. A polycarbonate sheet stacking device according to claim 3, characterized in that: The isolation mechanism comprises four hanging plates (71), the four hanging plates (71) are fixedly connected to one side of the outer wall of the funnel frame (3), two hanging plates (71) form a group, a sliding block (72) is slidably connected between the lower parts of the two hanging plates (71) in each group, a return spring (73) is connected between the sliding block (72) and the hanging plates (71), wherein the lower parts of the two hanging plates (71) are fixedly connected to side rods (74), the lower part of each side rod (74) is rotatably connected to a swing rod (75), the swing rod (75) is provided with a guide groove, the lower part of each sliding block (72) is fixedly connected to a connecting rod (76), the connecting rod (76) is located in the guide groove on the swing rod (75), the stacking plate (54) is fixedly connected to one side close to the hanging plate (71) with two top blocks (77), the two support frames (21) are slidably connected to inclined baffles (78), the lower parts of the two inclined baffles (78) close to one end of the stacking plate (54) are fixedly connected to inclined blocks (781), a pressure spring (79) is connected between the inclined baffle (78) and the support frame (21), and the pushing frame (58) is fixedly connected to one side close to the electric slider (42) with two right-angle push rods (710), and the right-angle push rods (710) are in contact with one end of the inclined baffle (78).

5. A polycarbonate sheet stacking device according to claim 4, characterized in that: The invention also comprises a drag reduction mechanism, which is arranged on the bottom plate (1) and is used to reduce the resistance of the plates when the stacked plates are transferred. The drag reduction mechanism comprises two guide plates (81), each of which is slidably connected to a long sliding rod (82), and the long sliding rod (82) is provided with a plurality of inclined protrusions. A return spring (83) is connected between the long sliding rod (82) and the guide plate (81). Four limit plates (84) are fixedly connected to the bottom plate (1), and each two limit plates (84) form a group, and two limit plates (84) are fixedly connected to the bottom plate (1). The sliding long rod (82) passes through the two groups of the limiting plates (84) respectively. A plurality of straight rods (85) are fixedly connected to the bottom plate (1). Each of the straight rods (85) is slidably connected to a sliding plate (86). A tension spring (87) is connected between the sliding plate (86) and the straight rod (85). Every two sliding plates (86) form a group. A pulley (88) is rotatably connected between the two sliding plates (86) in each group. A cross bar (89) is fixedly connected between each group of sliding plates (86). The cross bar (89) contacts the sliding long rod (82).

Images