Sharp instrument collecting device

Abstract

The invention relates to the technical field of sharp instrument collection, in particular to a sharp instrument collection device which comprises a collection box, a placement part, a separation part, a placement disc, a separation part and a separation plate, and an opening is formed in the top of the collection box. According to the sharp instrument collecting device, the stepped containing disc is matched with needle tubes with different diameters, the triangular inclined face design of the separating plates is combined, when the needle tubes are pressed downwards, the sliding shafts move along the track of the inclined first sliding way, the separating plates are pushed to gather towards the center, and horizontal thrust and vertical pressure are generated after the inclined faces make contact with pintle pins; the needle head and the needle tube are rapidly stripped under the dual action, the separation efficiency is high, and labor is saved.

Description

Technical Field

[0001] The present invention relates to the technical field of sharp instrument collection, and particularly relates to a sharp instrument collection device. Background Art

[0002] Medical sharp instruments are devices carried by many instruments and equipment in hospitals, such as surgical blades, syringe assemblies, and needles, etc., all of which are composed of sharp sharp instruments.

[0003] Since the used syringe may remain with blood, body fluids, etc., these substances may carry pathogens, such as viruses, bacteria, etc. If the needle is not separated from the syringe barrel, during subsequent processing, such as handling and discarding, the needle is likely to accidentally stab the staff or others, resulting in the spread of pathogens and increasing the risk of infectious diseases.

[0004] The current treatment of used syringes mainly relies on manual labor. The manual separation method: medical staff or operators use tools such as tweezers and needle separators to manually unscrew or pull out the needle. The following risks exist in this process: infection risk: it is easy to cause needle stick injuries during the operation, resulting in the spread of blood-borne diseases such as hepatitis B and HIV; low efficiency: manual operation is time-consuming and laborious, especially in the scenario of processing a large number of syringes, the efficiency is insufficient; operation error: manual operation may cause needle damage, splashing or syringe barrel residue due to improper force, affecting the subsequent treatment effect.

[0005] Therefore, the present invention provides a sharp instrument collection device to solve the above problems. Summary of the Invention

[0006] In view of the above situation, to overcome the defects of the prior art, the present invention provides a sharp instrument collection device to solve the problem that it is easy to cause accidental injury when manually separating the needle from the syringe tube.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows: A sharp instrument collection device includes a collection box, the top of the collection box has an opening, and the inner cavity of the collection box is connected to the outside through the opening; A tip separation assembly is arranged in the collection box. The tip separation assembly includes a placement member. The placement member has a stepped inner cavity, and the diameter of the inner cavity decreases sequentially from top to bottom. Two vertically arranged placement plates are arranged inside the inner cavity, and the diameters of the two placement plates decrease sequentially from top to bottom. A separation member is arranged inside the placement member. The separation member includes two separation plates symmetrically installed at the bottom of the placement plate, and the separation plates are triangular in shape and are used to abut against the syringe hub to separate the needle from the syringe tube.

[0008] Preferably, the collection box is composed of an upper cylinder and a lower cylinder. Both the upper cylinder and the lower cylinder are concave. The concave cavity of the upper cylinder faces downward, and the concave cavity of the lower cylinder faces upward. The maximum diameter values of the upper cylinder and the lower cylinder are the same. The top of the upper cylinder has an opening, and the collection box is connected to the outside through the opening. The upper cylinder and the lower cylinder are connected by a threaded bolt.

[0009] Preferably, a top shaft is connected between the top of the separation plate and the bottom of the corresponding placement tray. A side block is installed on one side of the separation plate away from the axis of the placement member. A sliding opening adapted to the side block is formed on the outer wall of the upper cylinder, and the side block is slidably connected inside the sliding opening. The side block cooperates with the sliding opening to limit the separation plate.

[0010] Preferably, a first side plate member is provided on the placement member. Each first side plate member corresponds to a separation plate. Each first side plate member is composed of two first side plates. Each two first side plates correspond to a side block. Sliding shafts are fixed on both sides of each side block. First sliding grooves adapted to the sliding shafts are formed on the first side plate member, and the sliding shafts are slidably connected inside the first sliding grooves.

[0011] Preferably, a limiting member is provided on the separation plate. The limiting member includes a bottom column fixed to the bottom of the separation plate. A first return spring is fixed to the bottom of the bottom column. A slider is installed outside the bottom column. The slider has a groove, and the outer wall of the bottom column is slidably connected to the inner wall of the groove. The bottom of the first return spring is fixed to the inner bottom wall of the groove. A side connecting plate is fixed on the stepped surface of the inner cavity of the placement member, and a receiving groove is formed on the side of the side connecting plate facing the bottom column. An inner plate is fixed to the outer wall of the slider, and the inner plate is slidably connected inside the receiving groove.

[0012] Preferably, a pulling-away member is provided on the placement member. The pulling-away member includes a lifting disc installed at the bottom of the placement member. The lifting disc is in a frustum shape and has a through hole penetrating up and down. A limiting groove adapted to the top end of the lifting disc is formed at the bottom end of the placement member, and the top end of the lifting disc is slidably connected inside the limiting groove.

[0013] Preferably, two rotating shafts are symmetrically arranged inside the lifting disc. An extrusion block is arranged on the surface of the rotating shaft, and the extrusion block is in an oval shape. A positioning hole adapted to the rotating shaft is formed on the lifting disc, and the outer wall of the rotating shaft is rotatably connected to the inner wall of the positioning hole.

[0014] Preferably, first toothed rings are installed at both ends of the rotating shaft extending outside the positioning hole. Two end plates are symmetrically fixed to the outer wall of the bottom end of the placement member. First racks are arranged on both sides of each end plate. Each first rack corresponds to a first toothed ring, and the first toothed ring is meshed with the first rack.

[0015] Preferably, a lifting assembly is installed on the placing member. The lifting assembly includes a connecting frame fixed on the outer wall of the placing member. A top block is fixed on the top of the lifting disc. Each connecting frame corresponds to a top block. A driving shaft is rotatably connected to the inner wall of each connecting frame. A pulling rope is installed between the driving shaft and the top block.

[0016] Preferably, a connecting frame is installed on the surface of the driving shaft. A lifting plate is installed inside the connecting frame. A second rack and a positioning plate are installed on the side of the lifting plate facing the driving shaft. The second rack is meshed with the second toothed ring. A first limiting block is fixed on the side of the lifting plate facing the connecting frame. A second sliding groove adapted to the first limiting block is formed on the connecting frame. The first limiting block is slidably connected inside the corresponding second sliding groove. A lifting shaft is fixed on the bottom of the placing disc. A limiting through hole adapted to the lifting shaft is formed on the placing member. The lifting shaft is slidably connected inside the corresponding limiting through hole. The height of the lifting shaft from the edge to the center of the placing member decreases in sequence.

[0017] The beneficial effects of the present invention are as follows: 1. The collection box is composed of an upper cylinder and a lower cylinder, which are connected by a threaded bolt, facilitating disassembly and cleaning. At the same time, the concave design of the upper cylinder and the lower cylinder makes collection and storage more convenient.

[0018] 2. By using the stepped placing disc to adapt to syringes with different diameters, combined with the triangular inclined surface design of the separation plate, when the syringe is pressed down, the sliding shaft moves along the trajectory of the first inclined sliding groove, pushing the separation plate to gather towards the center. After the inclined surface contacts the syringe plug, a horizontal thrust and a vertical pressure are generated, and the needle head and the syringe are quickly peeled off under the dual action, with high separation efficiency and labor saving.

[0019] 3. By utilizing the diameter change at the long axis end of the ellipse, a periodic squeezing force and pulling force are applied to the needle head, and combined with the thrust of the separation plate, a "push-pull cooperation" mechanism is formed to ensure that the needle head is completely separated from the syringe, especially suitable for the type of needle head with a tight connection.

[0020] 4. When the placing disc moves downward, the positioning plate is squeezed by the lifting shaft, driving the lifting plate to slide along the second sliding groove. The driving shaft is rotated by the second rack, and the lifting disc is pulled upward by the pulling rope. The placing disc closer to the center corresponds to a higher-position lifting shaft, ensuring that when syringes of different specifications are pressed down, the lifting height of the lifting disc is adaptively matched with the needle head length, without manual adjustment, improving the versatility of the equipment. Description of the Drawings

[0021] Figure 1 is a schematic structural diagram of the present invention.

[0022] Figure 2 is a schematic structural diagram of the first three-dimensional cross-section of the collection box of the present invention.

[0023] Figure 3This is a schematic structural diagram of the tip separation component of the present invention.

[0024] Figure 4 This is a schematic structural diagram of the first three-dimensional cross-section of the placement member of the present invention.

[0025] Figure 5 This is a schematic structural diagram of the separation member of the present invention.

[0026] Figure 6 This is a schematic structural diagram of the limiting member of the present invention.

[0027] Figure 7 This is a schematic structural diagram of the lifting component of the present invention.

[0028] In the figure: 10. Collection box; 101. Upper cylinder; 102. Lower cylinder; 20. Tip separation component; 21. Placement member; 22. Placement plate; 23. Separation member; 230. Separation plate; 231. Side block; 232. Slide opening; 233. First side plate member; 234. First slideway; 235. Sliding shaft; 24. Limiting member; 240. Bottom column; 241. First return spring; 242. Slide block; 243. Side connection plate; 244. Inner plate; 25. Pulling-away member; 250. Lifting plate; 251. Rotating shaft; 252. Extrusion block; 253. First toothed ring; 254. End plate; 255. First rack; 30. Lifting component; 31. Connecting frame; 32. Top block; 33. Driving shaft; 34. Pulling rope; 35. Second toothed ring; 36. Lifting plate; 37. Second rack; 38. First limiting block; 39. Second slideway; 310. Lifting shaft; 311. Positioning plate. Detailed implementation mode

[0029] The following will refer to the reference drawings to explain each embodiment of the present invention in detail. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention.

[0030] As shown Figures 1-7 in the figure, a sharp instrument collection device includes a collection box 10, and the collection box 10 is composed of an upper cylinder 101 and a lower cylinder 102. Both the upper cylinder 101 and the lower cylinder 102 are concave, the concave cavity of the upper cylinder 101 faces downward, the concave cavity of the lower cylinder 102 faces upward, the maximum diameter values of the upper cylinder 101 and the lower cylinder 102 are the same, the top of the upper cylinder 101 has an opening, and the collection box 10 is connected to the outside through the opening. The upper cylinder 101 and the lower cylinder 102 are connected by threaded bolts.

[0031] The interior of the collection box 10 is provided with a tip separation component 20 for separating the needle from the syringe barrel.

[0032] The tip separation component 20 includes a placement member 21 installed inside the upper cylinder 101. The placement member 21 is in the shape of an inverted convex platform. The placement member 21 has a stepped inner cavity, and the diameter of the inner cavity decreases sequentially from top to bottom. The inner walls of the inner cavity are both slidably connected with two placement plates 22 arranged vertically. Both placement plates 22 are hollow. The diameter values of the placement plates 22 in the inner cavity decrease sequentially from top to bottom, and the inner hole diameter value of the upper placement plate 22 is the same as the maximum diameter value of the lower placement plate 22.

[0033] A separation member 23 is provided inside the placement member 21 for separating the needle from the syringe barrel.

[0034] The separation member 23 includes two separation plates 230 symmetrically installed at the bottom of the placement plate 22, and two separation plates 230 correspond to the bottom of each placement plate 22. The separation plates 230 are triangular, and the inclined surfaces of the separation plates 230 face the axis of the placement member 21. The top of the separation plate 230 is connected to the bottom of the corresponding placement plate 22 by a top shaft. A side block 231 is installed on the side of the separation plate 230 away from the axis of the placement member 21. A sliding opening 232 adapted to the side block 231 is provided on the outer wall of the upper cylinder 101, and the side block 231 is slidably connected inside the sliding opening 232. The side block 231 cooperates with the sliding opening 232 to limit the separation plate 230, so as to maintain the stability of the separation plate 230 during up and down sliding.

[0035] First side plate members 233 are symmetrically fixed on the stepped surfaces of the placement member 21 from top to bottom. Each first side plate member 233 corresponds to one separation plate 230. Each first side plate member 233 is composed of two first side plates, and every two first side plates correspond to one side block 231. Sliding shafts 235 are fixed on both sides of each side block 231. First sliding channels 234 adapted to the sliding shafts 235 are provided on the first side plate members 233. The sliding shafts 235 are slidably connected inside the first sliding channels 234, and the first sliding channels 234 are inclined. The top end of the first sliding channel 234 is far away from the placement member 21, the bottom end of the first sliding channel 234 is close to the placement member 21, and the initial position of the sliding shaft 235 is at the top end of the first sliding channel 234.

[0036] A limiting member 24 is provided on the separation plate 230 for limiting the separation plate 230, so as to maintain the stability of the separation plate 230 during sliding.

[0037] The limiting member 24 includes a bottom post 240 fixed to the bottom of the separation plate 230. A first return spring 241 is fixed to the bottom of the bottom post 240. The bottom post 240 cooperates with the first return spring 241 to support the separation plate 230, thereby maintaining the stability of the separation plate 230 during sliding. A slider 242 is installed outside the bottom post 240. The slider 242 has a groove, and the outer wall of the bottom post 240 is slidably connected to the inner wall of the groove. The bottom of the first return spring 241 is fixed to the inner bottom wall of the groove. A side connecting plate 243 is fixed to the stepped surface inside the placing member 21. One side of the side connecting plate 243 facing the bottom post 240 has a receiving groove. An inner plate 244 is fixed to the outer wall of the slider 242, and the inner plate 244 is slidably connected inside the receiving groove.

[0038] A pulling-away member 25 is provided on the placing member 21 for cooperating with the separating member 23 to separate the needle from the syringe.

[0039] The pulling-away member 25 includes a lifting disc 250 installed at the bottom of the placing member 21. The lifting disc 250 is in the shape of a boss and has a through hole that penetrates up and down. The needle can fall into the interior of the lower cylinder 102 through the through hole of the lifting disc 250 for collection. A limiting groove adapted to the top end of the lifting disc 250 is provided at the bottom end of the placing member 21, and the top end of the lifting disc 250 is slidably connected inside the limiting groove.

[0040] Two rotating shafts 251 are symmetrically arranged inside the lifting disc 250. An extrusion block 252 is provided on the surface of the rotating shaft 251, and the extrusion block 252 is elliptical. When the rotating shafts 251 rotate synchronously and in opposite directions, the two extrusion blocks 252 can extrude the needle and drive the needle to move downward to separate it from the syringe. A positioning hole adapted to the rotating shaft 251 is provided on the lifting disc 250, and the outer wall of the rotating shaft 251 is rotatably connected to the inner wall of the positioning hole.

[0041] Both ends of the rotating shaft 251 extending outside the positioning hole are installed with first toothed rings 253. Two end plates 254 are symmetrically fixed to the outer wall of the bottom end of the placing member 21. First racks 255 are provided on both sides of each end plate 254. Each first rack 255 corresponds to one first toothed ring 253, and the first toothed ring 253 is meshed with the first rack 255.

[0042] When the syringe after use needs to be separated from the needle connected to it, the surface where the syringe is connected to the needle is abutted against the placing disc 22 corresponding to its diameter. After the bottom end of the syringe abuts against the placing disc 22, the syringe is pushed downward. The placing disc 22 in the downward movement state drives the side block 231 to slide inside the sliding opening 232, and the side block 231 also drives the sliding shaft 235 to slide synchronously along the track of the first slideway 234. At this time, the sliding shaft 235 slides from the top end to the bottom end of the first slideway 234, and the stroke of the first slideway 234 is the same as the stroke of the receiving groove.

[0043] As the sliding shaft 235 is inside the first slideway 234, the sliding shaft 235 pushes the separation plate 230 to slide toward the middle of the placement piece 21 through the side block 231, and the first side plate 233 slides inside the first slideway 234. As the separation plate 230 slides toward the middle of the placement piece 21, the top of the separation plate 230 will first contact the needle bolt of the needle, and the needle bolt slides from the top of the separation plate 230 to its bottom end. The separation plate 230 will move the needle downward, thereby applying pressure to the needle to make it detach from the needle tube, and the lifting plate 250 can move up at the bottom end of the placement piece 21. At this time, the first tooth ring 253 cooperates with the first rack 255 to drive the rotating shaft 251 to rotate.

[0044] Since the extrusion block 252 is elliptical and the initial position of the end with a larger diameter of the extrusion block 252 is far away from the axis of the placement piece 21, as the rotating shaft 251 rotates, the end with a larger diameter of the extrusion block 252 will contact the needle and squeeze it, and the rotation of the rotating shaft 251 will apply a pulling force to the needle through the extrusion block 252, thereby ensuring that the needle can be detached from the needle tube.

[0045] A lifting assembly 30 is installed on the placement member 21 for controlling the height of the lifting plate 250 .

[0046] The lifting assembly 30 includes a connecting frame 31 fixed on the outer wall of the placement piece 21, a top block 32 is fixed on the top of the lifting plate 250, each connecting frame 31 corresponds to a top block 32, and the inner wall of each connecting frame 31 is rotatably connected to a driving shaft 33, and a pull rope 34 is installed between the driving shaft 33 and the top block 32.

[0047] A connecting frame 31 is installed on the surface of the driving shaft 33, and a lifting plate 36 is installed inside the connecting frame 31. A second rack 37 and a positioning plate 311 are installed on the side of the lifting plate 36 facing the driving shaft 33, and the second rack 37 is meshed and connected with the second gear ring 35. A first limit block 38 is fixed to the side of the lifting plate 36 facing the connecting frame 31. A second slide 39 matched with the first limit block 38 is opened on the connecting frame 31, and the first limit block 38 is slidably connected inside the corresponding second slide 39. A lifting shaft 310 is fixed to the bottom of the placement plate 22, and a limiting through hole matched with the lifting shaft 310 is opened on the placement piece 21, and the lifting shaft 310 is slidably connected inside the corresponding limiting through hole, and the height of the lifting shaft 310 from the edge of the placement piece 21 to its axis decreases successively.

[0048] When the placement tray 22 moves downward, the lifting shaft 310 moves downward inside the corresponding limit through-hole, and the lifting shaft 310 presses the positioning plate 311 to drive the lifting plate 36 to move downward. The lifting plate 36 drives the drive shaft 33 to rotate through the second rack 37. The drive shaft 33 drives the lifting tray 250 to move upward in height through the pull rope 34 and the top block 32, so as to facilitate the pressing block 252 to adapt to needles of different heights. Since the height of the rotating shaft 251 close to the axis of the placement member 21 is higher than the height of the rotating shaft 251 far from the axis of the placement member 21, even when the rotating shaft 251 far from the axis of the placement member 21 and the rotating shaft 251 close to the axis of the placement member 21 move downward synchronously, it is the rotating shaft 251 far from the axis of the placement member 21 that first contacts the positioning plate 311 and drives the lifting plate 36 to move downward in height.

[0049] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A sharp object collection device, characterized in that, Comprising a collection box (10), the top of the collection box (10) has an opening, and the inner cavity of the collection box (10) is connected to the outside through the opening; A tip separation assembly (20), the tip separation assembly (20) is arranged inside the collection box (10), the tip separation assembly (20) includes a placement member (21), the placement member (21) has a stepped inner cavity, and the diameter of the inner cavity decreases sequentially from top to bottom. Two vertically arranged placement discs (22) are arranged inside the inner cavity, and the diameters of the two placement discs (22) decrease sequentially from top to bottom. A separation member (23) is arranged inside the placement member (21), the separation member (23) includes two separation plates (230) symmetrically installed at the bottom of the placement disc (22), and the separation plates (230) are triangular in shape and are used to abut against the syringe hub to separate the needle tip from the needle tube.

2. The sharp instrument collecting device according to claim 1, characterized in that, The collection box (10) is composed of an upper cylinder (101) and a lower cylinder (102). Both the upper cylinder (101) and the lower cylinder (102) are concave in shape, and the concave cavity of the upper cylinder (101) faces downward, while the concave cavity of the lower cylinder (102) faces upward. The maximum diameter values of the upper cylinder (101) and the lower cylinder (102) are the same. The top of the upper cylinder (101) has an opening, and the collection box (10) is connected to the outside through the opening. The upper cylinder (101) and the lower cylinder (102) are connected by threaded bolts.

3. The sharp object collecting device according to claim 2, wherein, A top shaft is connected between the top of the separation plate (230) and the bottom of the corresponding placement disc (22). A side block (231) is installed on the side of the separation plate (230) away from the axis of the placement member (21). A sliding opening (232) adapted to the side block (231) is formed on the outer wall of the upper cylinder (101), and the side block (231) is slidably connected inside the sliding opening (232). The side block (231) and the sliding opening (232) cooperate to limit the separation plate (230).

4. A sharp instrument collecting device according to claim 3, characterized in that, The placement member (21) is provided with a first side plate member (233). Each first side plate member (233) corresponds to a separation plate (230). Each first side plate member (233) is composed of two first side plates. Each pair of first side plates corresponds to a side block (231). Sliding shafts (235) are fixed on both sides of each side block (231). A first sliding track (234) adapted to the sliding shafts (235) is formed on the first side plate member (233), and the sliding shafts (235) are slidably connected inside the first sliding track (234).

5. The sharp instrument collecting device according to claim 4, characterized in that, A limiting member (24) is provided on the separation plate (230). The limiting member (24) includes a bottom post (240) fixed to the bottom of the separation plate (230). A first return spring (241) is fixed to the bottom of the bottom post (240). A slider (242) is installed outside the bottom post (240). The slider (242) has a groove, and the outer wall of the bottom post (240) is slidably connected to the inner wall of the groove. The bottom of the first return spring (241) is fixed to the inner bottom wall of the groove. A side connecting plate (243) is fixed to the stepped surface inside the placing member (21). One side of the side connecting plate (243) facing the bottom post (240) has a receiving groove. An inner plate (244) is fixed to the outer wall of the slider (242), and the inner plate (244) is slidably connected inside the receiving groove.

6. A sharp object collecting device according to claim 5, wherein, A pulling-away member (25) is provided on the placing member (21). The pulling-away member (25) includes a lifting disc (250) installed at the bottom of the placing member (21). The lifting disc (250) is in the shape of a boss and has a through hole penetrating up and down. A limiting groove adapted to the top end of the lifting disc (250) is provided at the bottom end of the placing member (21), and the top end of the lifting disc (250) is slidably connected inside the limiting groove.

7. The sharp instrument collecting device according to claim 6, characterized in that, Two rotating shafts (251) are symmetrically arranged inside the lifting disc (250). An extrusion block (252) is provided on the surface of the rotating shaft (251), and the extrusion block (252) is in an oval shape. A positioning hole adapted to the rotating shaft (251) is provided on the lifting disc (250), and the outer wall of the rotating shaft (251) is rotatably connected to the inner wall of the positioning hole.

8. A sharp instrument collection device according to claim 7, characterized in that, First toothed rings (253) are installed at both ends of the rotating shaft (251) extending outside the positioning hole. Two end plates (254) are symmetrically fixed to the outer wall of the bottom end of the placing member (21). First racks (255) are provided on both sides of each end plate (254). Each first rack (255) corresponds to a first toothed ring (253), and the first toothed ring (253) is meshed with the first rack (255).

9. A sharp object collection device according to claim 8, wherein, A lifting assembly (30) is installed on the placing member (21). The lifting assembly (30) includes a connecting frame (31) fixed to the outer wall of the placing member (21). A top block (32) is fixed to the top of the lifting disc (250). Each connecting frame (31) corresponds to a top block (32). A driving shaft (33) is rotatably connected to the inner wall of each connecting frame (31). A pulling rope (34) is installed between the driving shaft (33) and the top block (32).

10. A sharp instrument collection device according to claim 9, characterized in that, A connecting frame (31) is mounted on the surface of the drive shaft (33). A lifting plate (36) is mounted inside the connecting frame (31). A second rack (37) and a positioning plate (311) are mounted on one side of the lifting plate (36) facing the drive shaft (33). The second rack (37) is meshed and connected with a second gear ring (35). A first limiting block (38) is fixed on one side of the lifting plate (36) facing the connecting frame (31). A second sliding groove (39) adapted to the first limiting block (38) is formed in the connecting frame (31). The first limiting block (38) is slidably connected inside the corresponding second sliding groove (39). A lifting shaft (310) is fixed at the bottom of the placing disc (22). A limiting through hole adapted to the lifting shaft (310) is formed in the placing member (21). The lifting shaft (310) is slidably connected inside the corresponding limiting through hole. The height of the lifting shaft (310) from the edge of the placing member (21) to its axis decreases in sequence.

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