A kind of air hole opening device for patch production

Abstract

The utility model discloses a kind of ventilation hole setting device for application production, including operation platform, support side plate, lower roll of opening, upper roll of opening, opening assembly and first driving device, wherein, one end of upper roll of opening is fixedly connected with the output end of first driving device, the end of lower roll of opening and the other end of upper roll of opening are mutually sleeved by synchronous belt, and opening assembly is installed on lower roll of opening and upper roll of opening.The first assembly plate is installed in upper roll groove, the second assembly plate is installed in lower roll groove, and positioning plate is fixed with positioning bolt to prevent displacement;When double-roller is synchronously rotated, opening needle is inserted into jack to complete opening, second driving device carries out cleaning roll to clean opening needle, fan is through connecting pipeline and abutting sleeve board to insert jack waste into collection bin, and finally wind up;This structure is convenient to replace assembly plate and replace opening needle, also avoids that opening is blocked, precision is reduced and material is polluted due to waste residue, and product quality is guaranteed.

Description

Technical Field

[0001] This utility model relates to the field of dressing processing technology, and in particular to a device for creating vent holes in dressing production. Background Technology

[0002] Currently, in the production process of adhesive products, ventilation holes need to be made to achieve the breathability function. Commonly used ventilation hole making devices mostly include upper and lower opening rollers. The opening needle of the upper roller cooperates with the corresponding insertion hole of the lower roller to complete the punching operation during the material conveying process. Some devices use a simple transmission structure to drive the two rollers to rotate to achieve continuous opening.

[0003] However, existing equipment often lacks a targeted waste cleaning and collection mechanism, and waste generated during the perforation process easily remains on the surface of the perforating pin or inside the insertion hole. As production continues, the residual waste gradually accumulates, which not only affects the accuracy of subsequent perforations, causing problems such as misalignment and blockage of the vent holes, but may also contaminate the adhesive material, reducing product quality stability. Furthermore, the perforating pins used to create vent holes are not easy to replace, requiring the entire perforation roller to be replaced, which is not convenient. Utility Model Content

[0004] This utility model aims to at least partially solve one of the technical problems in the related art.

[0005] Therefore, the purpose of this utility model is to propose a ventilation hole opening device for patch production. The device uses a synchronous belt to achieve synchronous rotation of the upper and lower opening rollers, and is equipped with a detachable opening assembly. It also includes a cleaning mechanism and a collection assembly. The cleaning roller cleans the opening needles, and the collection assembly collects waste material inside the insertion hole through a fan, connecting pipe, and contact plate, thereby avoiding waste material residue and solving the problem of waste material accumulation affecting the opening accuracy and product quality.

[0006] To achieve the above objectives, this utility model proposes a ventilation hole opening device for patch production, comprising an operating table, a supporting side plate, a lower opening roller, an upper opening roller, an opening assembly, and a first driving device. The supporting side plate is symmetrically fixedly connected to the top center of the operating table. The lower and upper opening rollers are vertically distributed and rotatably connected to the inner wall of the supporting side plate. The first driving device is installed on the outer wall of the supporting side plate, and one end of the upper opening roller is fixedly connected to the output end of the first driving device. The end of the lower opening roller and the other end of the upper opening roller are sleeved together by a synchronous belt. A detachable opening assembly is installed on the lower and upper opening rollers.

[0007] This utility model discloses a ventilation hole opening device for patch production. The patch material is guided by guide rollers on both sides of the operating table support frame to the support side plates. The first drive device drives the upper opening roller to rotate, and the synchronous belt makes the lower opening roller rotate synchronously. The outer walls of the lower and upper opening rollers are arranged in a circumferential array with assembly grooves. The first assembly plate is installed in the upper roller groove, and the second assembly plate is installed in the lower roller groove. The positioning plate and positioning bolts are fixed to prevent displacement. When the two rollers rotate synchronously, the opening needle inserts into the insertion hole to complete the opening. The second drive device with cleaning roller cleans the opening needle. The fan collects the insertion hole waste to the collection bin through the connecting pipe and the contact sleeve plate, and finally rewinds it. This structure not only facilitates the replacement of the assembly plate and the opening needle, but also avoids the opening blockage, decrease in accuracy and material contamination caused by waste residue, thus ensuring product quality.

[0008] In addition, the ventilation hole opening device for patch production proposed above according to this utility model may also have the following additional technical features: Specifically, the perforation assembly includes a first assembly plate, a second assembly plate, a positioning plate, and positioning bolts. The outer walls of the lower and upper perforation rollers are provided with assembly grooves arranged in a circumferential array. Multiple first assembly plates are installed in the assembly grooves on the upper perforation roller, and multiple second assembly plates are installed in the assembly grooves on the lower perforation roller. Perforation pins are fixedly connected to the first assembly plates at equal intervals, and insertion holes are provided on the second assembly plates at equal intervals. Positioning plates are installed between the ends of the first and second assembly plates and the ends of the upper and lower perforation rollers. The positioning bolts are symmetrically installed on the positioning plates.

[0009] Specifically, it also includes a cleaning mechanism, which includes a second drive device, a support arm, a cleaning roller, and a collection assembly. The second drive device is installed on the outer wall of one of the support side plates. One end of the support arm is fixedly connected to the top of the other support side plate. One end of the cleaning roller is rotatably connected to the other end of the support arm. The output end of the second drive device passes through the outer wall of one of the support side plates and is fixedly connected to the other end of the cleaning roller. The collection assembly is installed on the top of the operating table and is connected to the perforated lower roller.

[0010] Specifically, the collection assembly includes a collection chamber, a fan, an abutment sleeve, and a connecting pipe. The collection chamber and the fan are both installed on the top of the operating table, and the output end of the fan is connected to the collection chamber. The two ends of the abutment sleeve are fixedly connected to the inner wall of the support side plate, and the inner wall of the abutment sleeve abuts against the outer wall of the perforated lower roller. The connecting pipe is provided between the outer wall of the abutment sleeve and the input end of the fan, and the two are connected through the connecting pipe.

[0011] Specifically, the top of the operating table is symmetrically and fixedly connected to the two sides of the supporting side plate, and the inner wall of the supporting frame is rotatably connected to the guide roller.

[0012] Specifically, the inner wall of the abutment sleeve is provided with a suction groove, the width of which is the same as the width of the second assembly plate.

[0013] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0014] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, in which: Figure 1 This is a schematic diagram of the ventilation hole opening device for the application of this utility model in the production of adhesive dressings; Figure 2 This is a schematic diagram of the structure of the collecting components according to one embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the second assembly plate according to one embodiment of the present invention; Figure 4 This is one embodiment of the present utility model. Figure 2 Enlarged structural diagram at point A in the middle.

[0015] As shown in the figure: 1. Operating table; 2. Support frame; 3. Guide roller; 4. Support side plate; 5. Perforated lower roller; 6. Perforated upper roller; 7. Hole-opening assembly; 71. First assembly plate; 711. Hole-opening pin; 72. Second assembly plate; 721. Insertion hole; 73. Positioning plate; 74. Positioning bolt; 8. First driving device; 9. Cleaning mechanism; 91. Second drive unit; 92. Support arm; 93. Cleaning roller; 94. Collection assembly; 941. Collection bin; 942. Fan; 943. Contact plate; 944. Connecting pipe. Detailed Implementation

[0016] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this utility model, and should not be construed as limiting this utility model. Rather, the embodiments of this utility model include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0017] The ventilation hole opening device for patch production according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0018] like Figures 1-4 As shown, the ventilation hole opening device for patch production according to this utility model embodiment may include an operating table 1, a supporting side plate 4, a lower opening roller 5, an upper opening roller 6, an opening assembly 7, and a first driving device 8.

[0019] The supporting side plate 4 is symmetrically fixedly connected to the top middle of the operating table 1. The perforated lower roller 5 and the perforated upper roller 6 are distributed vertically and rotatably connected to the inner wall of the supporting side plate 4. The first driving device 8 is installed on the outer wall of the supporting side plate 4, and one end of the perforated upper roller 6 is fixedly connected to the output end of the first driving device 8. The end of the perforated lower roller 5 and the other end of the perforated upper roller 6 are connected to each other by a synchronous belt.

[0020] It should be noted that the support side plate 4 described in this embodiment is symmetrically fixed to the top of the operating table 1, providing rigid support for the lower perforation roller 5 and the upper perforation roller 6, ensuring the stability of their axis parallelism during high-speed rotation, and preventing misalignment of the perforation needle 711 and the insertion hole 721 due to unstable support. The first drive device 8 is installed on the outer wall of the support side plate 4, which facilitates power transmission to the upper perforation roller 6 and avoids occupying the working space between the two rollers. The synchronous belt connects the ends of the lower perforation roller 5 and the upper perforation roller 6, ensuring that their rotation speeds are completely consistent, so that the application material is subjected to uniform force during the conveying process, improving the continuity and consistency of the perforation. The first drive device 8 is a drive motor.

[0021] A detachable perforation assembly 7 is installed on the lower perforation roller 5 and the upper perforation roller 6.

[0022] It should be noted that the perforation assembly 7 described in this embodiment is designed to be detachable from the lower perforation roller 5 and the upper perforation roller 6. When it is necessary to adjust the parameters such as the diameter and spacing of the vent holes, the perforation assembly 7 can be directly replaced without disassembling the entire lower perforation roller 5 or the upper perforation roller 6. This not only simplifies the adjustment process but also reduces equipment downtime. At the same time, it is convenient to maintain or replace worn parts of the perforation assembly 7 separately, thus extending the overall service life of the lower perforation roller 5 and the upper perforation roller 6.

[0023] Specifically, during operation, the material to be applied is guided by guide rollers 3 on the support frames 2 on both sides of the operating table 1 to the space between the support side plates 4. The first drive device 8 drives the upper opening roller 6 to rotate, and the lower opening roller 5 rotates synchronously with the upper opening roller 6 via a synchronous belt, so that the two maintain the same speed to transport the material. The detachable opening assembly 7 on the upper opening roller 6 and the lower opening roller 5 completes the opening of the ventilation hole by cooperating with the insertion hole 721 through the opening pin 711. At the same time, the cleaning roller 93 in the cleaning mechanism 9 cleans the opening pin 711. The collection assembly 94 collects the waste in the insertion hole 721 into the collection bin 941 through the fan 942, the connecting pipe 943 and the contact sleeve 944. By cleaning the opening pin 711 and collecting the waste in the insertion hole 721, the problem of reduced opening accuracy and product quality caused by the accumulation of waste residue in the prior art is avoided.

[0024] In one embodiment of this utility model, such as Figures 1-4 As shown, the perforation assembly 7 includes a first assembly plate 71, a second assembly plate 72, a positioning plate 73, and positioning bolts 74. The outer walls of the lower perforated roller 5 and the upper perforated roller 6 are provided with assembly grooves arranged in a circumferential array. Multiple first assembly plates 71 are installed in the assembly grooves on the upper perforated roller 6, and multiple second assembly plates 72 are installed in the assembly grooves on the lower perforated roller 5. Perforation pins 711 are fixedly connected to the first assembly plates 71 at equal intervals, and insertion holes 721 are provided on the second assembly plates 72 at equal intervals. Positioning plates 73 are installed between the ends of the first assembly plates 71 and the second assembly plates 72 and the ends of the upper perforated roller 6 and the lower perforated roller 5. Positioning bolts 74 are symmetrically installed on the positioning plates 73. It should be noted that the outer walls of the perforated lower roller 5 and perforated upper roller 6 described in this embodiment are provided with circumferentially arrayed assembly grooves. This ensures that the first assembly plate 71 and the second assembly plate 72 are evenly distributed along the circumference of the roller body, guaranteeing a consistent density of the ventilation holes on the application material and preventing local perforations from being too dense or too sparse. The perforation needles 711 on the first assembly plate 71 are correspondingly positioned with the insertion holes 721 on the second assembly plate 72, ensuring that the perforation needles 711 are accurately inserted into the insertion holes 721 during piercing and preventing damage to the perforation needles 711 due to misalignment or bending. At the same time, the cooperation between the positioning plate 73 and the positioning bolts 74 firmly fixes the assembly plates in the assembly grooves, preventing the assembly plates from shifting when the roller body rotates, further ensuring the accuracy of the perforation positions.

[0025] Specifically, when the perforation assembly 7 is in operation, the first assembly plate 71 with the perforation needle 711 is first installed into the assembly groove of the upper perforation roller 6, and the second assembly plate 72 with the insertion hole 721 is installed into the assembly groove of the lower perforation roller 5. Then, the two ends of the assembly plate are fixed by the positioning plate 73 and the positioning bolt 74. When the upper perforation roller 6 and the lower perforation roller 5 rotate synchronously, the perforation needle 711 can accurately align with the insertion hole 721 and pierce the material. This avoids the perforation misalignment caused by the displacement of the assembly plate and prevents the perforation needle 711 from being damaged. It solves the problem in the background technology that the perforation accuracy is reduced and the product quality is affected by the unstable or misaligned positioning of the perforation component.

[0026] In one embodiment of this utility model, such as Figures 1-4 As shown, it also includes a cleaning mechanism 9, which includes a second drive device 91, a support arm 92, a cleaning roller 93, and a collection assembly 94. The second drive device 91 is installed on the outer wall of one of the support side plates 4. One end of the support arm 92 is fixedly connected to the top of the other support side plate 4. One end of the cleaning roller 93 is rotatably connected to the other end of the support arm 92. The output end of the second drive device 91 passes through the outer wall of one of the support side plates 4 and is fixedly connected to the other end of the cleaning roller 93. The collection assembly 94 is installed on the top of the operating table 1 and is connected to the perforated lower roller 5.

[0027] It should be noted that the second drive device 91 described in this embodiment is installed on the outer wall of the support side plate 4, which can conveniently provide power to the cleaning roller 93 without occupying the space of the opening area, thus avoiding interference with the delivery of the application material. One end of the support arm 92 is fixed to the top of the support side plate 4, and the other end is rotatably connected to the cleaning roller 93, which can ensure that the cleaning roller 93 stably adheres to the opening needle 711 of the opening roller 6, ensuring a uniform cleaning effect. The cleaning roller 93 is set in conjunction with the collection component 94 to realize the linkage of "cleaning and collection", avoiding secondary spillage and contamination of the equipment or application material by the waste material after cleaning. The second drive device 91 is a drive motor.

[0028] Specifically, when the cleaning mechanism 9 is working, the second drive device 91 starts and drives the cleaning roller 93 to rotate. The cleaning roller 93, supported by the support arm 92, adheres to the opening needle 711 on the upper opening roller 6 and cleans off the residual adhesive waste on the surface of the opening needle 711. At the same time, the collection component 94 operates synchronously to collect the waste at the lower opening roller 5, forming a comprehensive treatment of the waste during the opening process. This solves the problem in the background technology that the waste residue on the surface of the opening component causes subsequent opening blockage and reduced accuracy.

[0029] In one embodiment of this utility model, such as Figures 1-4As shown, the collection assembly 94 includes a collection chamber 941, a blower 942, an abutment plate 943, and a connecting pipe 944. The collection chamber 941 and the blower 942 are both installed on the top of the operating table 1, and the output end of the blower 942 is connected to the collection chamber 941. The two ends of the abutment plate 943 are fixedly connected to the inner wall of the support side plate 4, and the inner wall of the abutment plate 943 abuts against the outer wall of the perforated lower roller 5. A connecting pipe 944 is provided between the outer wall of the abutment plate 943 and the input end of the blower 942, and they are connected through the connecting pipe 944.

[0030] It should be noted that, in this embodiment, the inner wall of the contact plate 943 abuts against the outer wall of the perforated lower roller 5, forming a relatively sealed space to prevent negative pressure leakage generated by the blower 942 and ensure waste collection efficiency. The connecting pipe 944 connects the contact plate 943 and the blower 942, which can stably transport the waste collected at the contact plate 943 to the blower 942. The blower 942 is connected to the collection chamber 941, which can quickly store the sucked-in waste, avoiding waste accumulation and blockage in the pipe. At the same time, the collection chamber 941 facilitates subsequent centralized cleaning of waste.

[0031] Specifically, when the collection component 94 is working, the blower 942 starts to generate negative pressure. The negative pressure is transmitted to the inner wall of the contact sleeve 943 through the connecting pipe 944. Since the contact sleeve 943 is in contact with the outer wall of the lower roller 5 with the opening, the waste material remaining in the insertion hole 721 of the second mounting plate 72 on the lower roller 5 with the opening is sucked into the contact sleeve 943 by the negative pressure, and then enters the blower 942 through the connecting pipe 944. Finally, the blower 942 transports it to the collection bin 941 for storage, realizing the accurate collection of waste material in the insertion hole 721. This solves the problem in the background technology that the accumulation of waste material in the insertion hole 721 causes the opening to be blocked and affects the subsequent opening quality.

[0032] In one embodiment of this utility model, such as Figures 1-4 As shown, the top of the operating table 1 is symmetrically and fixedly connected to the two sides of the support side plate 4, and the inner wall of the support frame 2 is rotatably connected to the guide roller 3.

[0033] It should be noted that the support frame 2 described in this embodiment is symmetrically arranged on the top of the operating table 1 relative to the support side plate 4, which enables the guide roller 3 to form a straight conveying path with the lower perforated roller 5 and the upper perforated roller 6, avoiding deviation during the conveying of the application material. The guide roller 3 is rotatably connected to the inner wall of the support frame 2. Its smooth rotation reduces friction with the application material, preventing scratches on the material surface, while ensuring a stable material conveying speed that matches the rotation rhythm of the perforated roller, avoiding uneven perforation spacing caused by excessively fast or slow material conveying.

[0034] Specifically, when the support frame 2 and guide roller 3 are working, the application material to be processed first passes through the guide roller 3 on the support frame 2 on one side of the operating table 1. Under the guidance of the guide roller 3, it enters the opening area between the support side plates 4 with a stable posture. After the opening is completed, it is then discharged through the guide roller 3 on the other side. The material will not shift or wrinkle during the entire conveying process, ensuring that the opening position is accurately aligned. This solves the problem in the background technology that the opening position is misaligned due to the material conveying shift, which affects the product quality.

[0035] In one embodiment of this utility model, such as Figures 1-4 As shown, the inner wall of the contact sleeve 943 is provided with a suction groove, the width of which is the same as the width of the second assembly plate 72.

[0036] It should be noted that the width of the suction groove on the inner wall of the contact sleeve 943 described in this embodiment is the same as the width of the second assembly plate 72. This allows the suction groove to accurately cover the area of ​​the second assembly plate 72, ensuring that waste in all the insertion holes 721 on the second assembly plate 72 can be sucked in by negative pressure. This avoids the negative pressure dispersion and reduced collection efficiency caused by the suction groove being too wide, or the waste in some insertion holes 721 not being collected due to the width being too small. At the same time, matching the width of the suction groove with the width of the second assembly plate 72 can also reduce the intake of air in unnecessary areas, reduce the energy consumption of the fan 942, and improve the targeting of waste collection.

[0037] Specifically, when the lower roller 5 rotates, the second assembly plate 72 rotates with the roller to a position where it fits against the contact sleeve 943. Since the width of the suction groove of the contact sleeve 943 is the same as the width of the second assembly plate 72, the suction groove just completely covers all the insertion holes 721 on the second assembly plate 72. The negative pressure generated by the fan 942 can completely suck in the waste in each insertion hole 721, and no waste in the insertion hole 721 will be missed. This solves the problem in the background technology that the subsequent opening is blocked due to incomplete waste collection and residue in the insertion hole 721.

[0038] It should be understood that the application material is wound up by a drive device that rotates the take-up roller.

[0039] In summary, the ventilation hole opening device for patch production according to this utility model embodiment guides the patch material to the support side plates 4 via guide rollers 3 on both sides of the support frame 2 of the operating table 1. The first drive device 8 drives the upper opening roller 6 to rotate, and the synchronous belt makes the lower opening roller 5 rotate synchronously. The outer walls of the lower opening roller 5 and the upper roller 6 are arranged in a circumferential array with assembly grooves. The first assembly plate 71 is installed in the upper roller groove, and the second assembly plate 72 is installed in the lower roller groove. The positioning plate 73 and the positioning bolt 74 are fixed to prevent displacement. When the two rollers rotate synchronously, the opening needle 711 inserts into the insertion hole 721 to complete the opening. The second drive device 91 with the cleaning roller 93 cleans the opening needle. The fan 942 collects the insertion hole waste to the collection bin 941 through the connecting pipe 944 and the contact sleeve 943, and finally rewinds it. This structure not only facilitates the replacement of the assembly plate and the opening needle, but also avoids the opening blockage, decrease in accuracy and material contamination caused by waste residue, thus ensuring product quality.

[0040] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A device for creating vent holes in adhesive dressing production, characterized in that, It includes an operating table (1), a supporting side plate (4), a lower perforated roller (5), an upper perforated roller (6), a perforation assembly (7), and a first drive device (8), wherein, The supporting side plate (4) is symmetrically fixedly connected to the top middle of the operating table (1). The perforated lower roller (5) and the perforated upper roller (6) are distributed vertically and rotatably connected to the inner wall of the supporting side plate (4). The first driving device (8) is installed on the outer wall of the supporting side plate (4), and one end of the perforated upper roller (6) is fixedly connected to the output end of the first driving device (8). The end of the perforated lower roller (5) and the other end of the perforated upper roller (6) are connected to each other by a synchronous belt. The lower perforated roller (5) and the upper perforated roller (6) are equipped with detachable perforation assemblies (7).

2. The ventilation hole opening device for patch production according to claim 1, characterized in that, The opening assembly (7) includes a first mounting plate (71), a second mounting plate (72), a positioning plate (73), and positioning bolts (74), wherein, The outer walls of the perforated lower roller (5) and the perforated upper roller (6) are provided with assembly grooves in a circumferential array. Multiple first assembly plates (71) are installed in the assembly grooves on the perforated upper roller (6), and multiple second assembly plates (72) are installed in the assembly grooves on the perforated lower roller (5). Perforation pins (711) are fixedly connected at equal intervals on the first assembly plate (71), and insertion holes (721) are provided at equal intervals on the second assembly plate (72). Positioning plates (73) are installed between the ends of the first assembly plate (71) and the second assembly plate (72) and the ends of the perforated upper roller (6) and the perforated lower roller (5). Positioning bolts (74) are symmetrically installed on the positioning plates (73).

3. The ventilation hole opening device for patch production according to claim 2, characterized in that, It also includes a cleaning mechanism (9), which comprises a second drive unit (91), a support arm (92), a cleaning roller (93), and a collection assembly (94), wherein, The second drive device (91) is installed on the outer wall of one of the support side plates (4), one end of the support arm (92) is fixedly connected to the top of the other support side plate (4), one end of the cleaning roller (93) is rotatably connected to the other end of the support arm (92), and the output end of the second drive device (91) passes through the outer wall of one of the support side plates (4) and is fixedly connected to the other end of the cleaning roller (93). The collecting assembly (94) is mounted on the top of the operating table (1) and connected to the perforated lower roller (5).

4. The ventilation hole opening device for patch production according to claim 3, characterized in that, The collection assembly (94) includes a collection chamber (941), a fan (942), an abutment sleeve (943), and a connecting pipe (944), wherein, The collection chamber (941) and the fan (942) are both installed on the top of the operating table (1), and the output end of the fan (942) is connected to the collection chamber (941); The two ends of the abutting sleeve (943) are fixedly connected to the inner wall of the supporting side plate (4), and the inner wall of the abutting sleeve (943) abuts against the outer wall of the perforated lower roller (5). The connecting pipe (944) is provided between the outer wall of the contact sleeve (943) and the input end of the fan (942), and they are connected through the connecting pipe (944).

5. The ventilation hole opening device for patch production according to claim 1, characterized in that, The top of the operating table (1) is symmetrically fixedly connected to the two sides of the supporting side plate (4) with a support frame (2), and the inner wall of the support frame (2) is rotatably connected to a guide roller (3).

6. The vent hole opening device for patch production according to claim 4, characterized in that, The inner wall of the abutment sleeve (943) is provided with a suction groove, the width of which is the same as the width of the second assembly plate (72).

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