Auxiliary device for cigarette case packaging paperboard inspection machine
By setting up support frames and lifting plates on the inspection machine, and utilizing guide arc surfaces and adjustment structures, the impact problem during the conveying of cigarette box cardboard was solved, ensuring the conveying quality and appearance integrity of the cigarette box cardboard.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI SPINNING DYEING LIFENG PRINTING PACKAGING
- Filing Date
- 2025-05-09
- Publication Date
- 2026-05-01
AI Technical Summary
During the conveying process of the cigarette box cardboard inspection machine, the front end of the rear cigarette box cardboard is prone to collide with the square stacked plate that is raised on the front cigarette box cardboard, resulting in damage to the appearance integrity of the cigarette box.
The system employs a support frame and a lifting plate structure. The lifting plate is located above the conveyor belt of the inspection machine. Through the guide arc surface and adjustment structure, it ensures that the cigarette box cardboard falls onto the lifting plate first during the conveying process, and then falls from above the front cigarette box cardboard to avoid impact.
This effectively avoids impact marks on the cigarette box cardboard during the conveying process, ensuring the conveying quality and appearance integrity of the cigarette box cardboard.
Smart Images

Figure CN224185478U_ABST
Abstract
Description
An auxiliary device for a cigarette box packaging cardboard inspection machine Technical Field
[0001] This application relates to the field of cigarette box packaging paperboard production technology, and in particular to an auxiliary device for a cigarette box packaging paperboard inspection machine. Background Technology
[0002] The production process of cigarette boxes typically includes: plate making, printing, hot stamping, laser transfer printing, die-cutting, inspection, and shipping. During the printing process, due to various reasons, imperfections are inevitable in the appearance of the cigarette boxes. Therefore, to ensure quality, manufacturers must use inspection machines to visually inspect the produced cardboard boxes, selecting qualified boxes and rejecting defective ones. When using the inspection machine, a stack of cardboard is usually placed directly at the loading point. As the conveyor belt moves within the machine, the cardboard boxes are conveyed one by one. During this transmission, the inspection mechanism on the machine checks the surface quality of the cardboard boxes. After inspection, the cardboard boxes are re-stacked into a fish-scale pattern under the continued transmission of the machine, making it easier for subsequent workers to reassemble them into a single stack.
[0003] As shown in Figure 1, the existing cigarette box cardboard 9, when flattened, includes: an integrally formed bottom side panel 91, front side panel 92, top side panel 93, rear side panel 94, left side panel 95, right side panel 96, front folding panel 97, and four square stacked panels 98. The bottom side panel 91, front side panel 92, top side panel 93, rear side panel 94, left side panel 95, and right side panel 96 are bent to form a rectangular box structure. One end of the front folding panel 97 is bent and formed on the front side panel 92, and the other end is bent and can be inserted into the box. The left side panel 95 and right side panel 96 are formed at both ends of the length direction of the rear side panel 94, respectively. The four square stacked panels 98 are divided into two groups, one group is connected to the front side panel 92, and the other group is connected to the rear side panel 94. Taking the front side panel 92 as an example, the two square stacked panels 98 are symmetrically arranged at both ends of the length direction of the front side panel 92.
[0004] During the process of re-forming the cigarette box cardboard 9 into a fish-scale pattern after inspection by the inspection machine 10, the cardboard 9 is conveyed one sheet at a time. Furthermore, the movable ends of the left side panel 95, right side panel 96, and four square stacked panels 98 on the formed cigarette box cardboard 9 are prone to warping. This causes the front side panel 92 or front folding panel 97 of the rear cigarette box cardboard 9 to easily collide with the warped left side panel 95, right side panel 96, or square stacked panels 98 on the front cigarette box cardboard 9 during conveying. When this situation occurs... If the front fold 97 of the rear cardboard collides with the left side panel 95, right side panel 96, or square stacked panel 98 of the front cardboard, the external integrity of the cigarette box will not be affected because the front fold 97 is inserted into the cigarette box after packaging. However, if the front side panel 92 of the rear cigarette box cardboard 9 collides with the left side panel 95, right side panel 96, or square stacked panel of the front cigarette box cardboard 9, impact marks will appear on the end of the front side panel 92 of the rear cigarette box cardboard 9, thus affecting the appearance integrity of the cigarette box and requiring improvement. Summary of the Invention
[0005] To address the issue that during the conveying of cigarette box paperboard in the inspection machine, the front end of the rear cigarette box paperboard easily collides with the raised square stacked plate on the front cigarette box paperboard, resulting in impact marks on the front end of the rear cigarette box paperboard, this application provides an auxiliary device for a cigarette box packaging paperboard inspection machine.
[0006] This application provides an auxiliary device for a cigarette box packaging cardboard inspection machine, which adopts the following technical solution:
[0007] An auxiliary device for a cigarette box packaging cardboard inspection machine includes two support frames mounted on the inspection machine. The two support frames are arranged symmetrically. Each support frame is equipped with a lifting plate for raising and guiding the conveying direction of the cigarette box cardboard. The lifting plate is located above the conveyor belt in the inspection machine.
[0008] By adopting the above technical solution, during use, with the cooperation of the support frame and the lifting plate, the cigarette box cardboard first falls onto the lifting plate during the transmission process. Thus, with the help of the lifting plate guiding the transmission direction of the cigarette box cardboard, the cigarette box cardboard behind falls from above the cigarette box cardboard in front and directly overlaps the cigarette box cardboard in front. This avoids the situation where the front side plate of the cigarette box cardboard behind easily collides with the square stacked plate on the cigarette box cardboard in front, thereby ensuring the transmission quality of the cigarette box cardboard.
[0009] Preferably, the lifting plate is provided with guide arc surfaces at both ends along the conveying direction of the cigarette box cardboard, and the guide arc surfaces extend toward the upper surface of the conveyor belt of the inspection machine.
[0010] By adopting the above technical solution, the movement of the cigarette box cardboard is guided by the guide arc surface during use, while avoiding the collision between the cigarette box cardboard and the end face of the lifting plate during the process of the cigarette box cardboard falling onto the lifting plate.
[0011] Preferably, the support frame has a first oblong hole, the length direction of which is parallel to the conveying direction of the cigarette box cardboard. The support frame is also provided with a fixing bolt, one end of which passes through the first oblong hole and is threaded onto the inspection machine.
[0012] By adopting the above technical solution, during use, the position of the lifting plate can be adjusted along the conveying direction of the cigarette box cardboard through the cooperation of the first waist-shaped hole and the fixing bolt, thereby ensuring that the cigarette box cardboard can fall onto the lifting plate first under different working conditions.
[0013] Preferably, the support frame includes a base plate, a vertical plate fixed on the base plate, and a sliding folding plate slidably disposed on the vertical plate. The sliding direction of the sliding folding plate is parallel to the height direction of the inspection machine. The vertical plate is provided with a positioning structure for positioning the sliding folding plate, and the lifting plate is disposed on the sliding folding plate.
[0014] By adopting the above technical solution, the height between the lifting plate and the surface of the inspection machine conveyor belt can be adjusted through the cooperation of the sliding folding plate and the positioning structure, thereby improving the applicability of the device.
[0015] Preferably, the positioning structure includes a clamping bolt disposed on the vertical plate and a clamping nut threadedly engaged with the clamping bolt. A second oblong hole is provided on the vertical plate, the length direction of which is parallel to the sliding direction of the sliding plate. A through hole is provided on the sliding plate. One end of the clamping bolt passes through the second oblong hole and the through hole and is connected to the clamping nut.
[0016] By adopting the above technical solution, when it is necessary to adjust the height of the lifting plate, simply tighten the abutment nut to loosen the clamping force of the abutment nut and the abutment bolt on the vertical plate. Then, the sliding folding plate can be moved so that the abutment bolt slides in the second oblong hole. After the adjustment is completed, tighten the abutment nut again so that the abutment nut and the abutment bolt clamp the vertical plate and the sliding folding plate, thereby achieving the positioning of the sliding folding plate. The whole process is simple and convenient to use.
[0017] Preferably, an insert plate is fixed to the end of the sliding folding plate away from the vertical plate, a U-shaped block is fixed to the raising plate, a slot is formed between the U-shaped block and the raising plate, the insert plate and the slot are slidably engaged, and the vertical plate is also provided with an adjustment structure for adjusting the distance between the raising plate and the sliding folding plate.
[0018] By adopting the above technical solution, during use, the distance between the two lifting plates is adjusted by adjusting the structure to drive the sliding plate, thereby ensuring that the cigarette box cardboard falls stably on the lifting plate.
[0019] Preferably, the adjustment structure includes an adjustment screw threaded to the vertical plate and two clamping nuts threaded with the adjustment screw. A connecting block is fixed on the U-shaped block, and a third oblong hole is provided on the connecting block. The length direction of the third oblong hole is parallel to the length direction of the second oblong hole. One end of the adjustment screw is located on one side of the vertical plate, and the other end of the adjustment screw passes through the third oblong hole. The two clamping nuts clamp the connecting block.
[0020] By adopting the above technical solution, when in use, rotating the adjusting screw will cause the adjusting screw to slide along its own axis. With the cooperation of the two clamping nuts, the sliding of the adjusting screw can drive the lifting plate to slide, thereby changing the position of the lifting plate. At the same time, the setting of the third oblong hole avoids the setting of the adjusting screw from affecting the sliding of the sliding plate.
[0021] Preferably, the end of the adjusting screw away from the connecting block is provided with a rotating head that facilitates the user to rotate the adjusting screw, and the rotating head is provided with friction texture.
[0022] By adopting the above technical solution, the rotating head and friction texture make it easier for users to adjust the bolts, increasing the convenience of adjusting the position of the lifting plate.
[0023] In summary, this application includes at least one of the following beneficial technical effects:
[0024] 1. With the cooperation of the support frame and the lifting plate, the cigarette box cardboard first falls on the lifting plate during the transmission process. With the help of the lifting plate to guide the transmission direction of the cigarette box cardboard, the cigarette box cardboard behind falls from above the cigarette box cardboard in front and directly overlaps the cigarette box cardboard in front. This avoids the situation where the front side plate of the cigarette box cardboard behind is prone to collide with the square stacked plate on the cigarette box cardboard in front, thus ensuring the transmission quality of the cigarette box cardboard.
[0025] 2. By using the first oblong hole and the fixing bolt, the position of the lifting plate can be adjusted along the conveying direction of the cigarette box cardboard, making the device suitable for different operating conditions;
[0026] 3. By combining the positioning structure and the sliding folding plate, the height of the raised plate can be adjusted. In addition, by combining the adjustment structure, the distance between the two raised plates can be adjusted, which further improves the applicability of the device. Attached Figure Description
[0027] Figure 1 is a schematic diagram of the structure of a flattened cigarette box cardboard, which is the main feature of the background technology of this application.
[0028] Figure 2 is an isometric schematic diagram of the main overall structure in Embodiment 1 of this application;
[0029] Figure 3 is an isometric schematic diagram of the raised plate structure in Embodiment 1 of this application;
[0030] Figure 4 is a schematic diagram showing the connection structure between the support frame and the lifting plate in Embodiment 2 of this application;
[0031] Figure 5 is an exploded view of the connection structure between the support frame and the lifting plate in Embodiment 2 of this application.
[0032] Reference numerals: 1. Support frame; 11. First oblong hole; 12. Fixing bolt; 13. Base plate; 14. Vertical plate; 141. Second oblong hole; 15. Sliding folding plate; 2. Lifting plate; 3. Guide arc surface; 4. Positioning structure; 41. Tightening bolt; 42. Tightening nut; 5. Insert plate; 6. U-shaped block; 7. Adjustment structure; 71. Adjusting screw; 72. Clamping nut; 73. Rotating head; 8. Connecting block; 81. Third oblong hole; 9. Cigarette box cardboard; 91. Bottom side plate; 92. Front side plate; 93. Top side plate; 94. Rear side plate; 95. Left side plate; 96. Right side plate; 97. Front folding plate; 98. Square stacking plate; 10. Inspection machine. Detailed Implementation
[0033] The present application will be further described in detail below with reference to Figures 2-5.
[0034] This application discloses an auxiliary device for a cigarette box packaging cardboard inspection machine.
[0035] Example 1:
[0036] Referring to Figures 2 and 3, an auxiliary device for a cigarette box packaging cardboard inspection machine includes two support frames 1 symmetrically arranged on both sides of the conveyor belt of the inspection machine 10. A first oblong hole 11 is provided on the support frame 1, and the length direction of the first oblong hole 11 is parallel to the conveying direction of the cigarette box cardboard 9. A fixing bolt 12 is provided on the support frame 1. The bottom end of the fixing bolt 12 passes through the first oblong hole 11 and is threaded onto the inspection machine 10. The nut of the fixing bolt 12 abuts against the side wall of the inspection machine 10. In use, the support frame 1 is fixed by tightening the fixing bolt 12 until the nut of the fixing bolt 12 is tightened against the support frame 1.
[0037] Referring to Figures 2 and 3, in order to ensure the stability of the support frame 1, two fixing bolts 12 are provided in this embodiment, and the spacing between the two fixing bolts 12 is less than the length of the first waist-shaped hole 11. That is, when the fixing bolts 12 are tightened and loosened, the position of the support frame 1 can be changed along the transmission direction of the cigarette box cardboard 9. A lifting plate 2 is fixedly connected to the support frame 1 by bolts. The lifting plate 2 is used to raise and guide the transmission direction of the cigarette box cardboard 9. When the speed of the cigarette box cardboard 9 conveyed on the inspection machine 10 is different, the cigarette box cardboard 9 is subjected to inertia, resulting in different positions of the cigarette box cardboard 9 on the conveyor belt. At this time, the position of the lifting plate 2 can be adapted to the different transmission speeds of the cigarette box cardboard 9 by adjusting the position of the support frame 1.
[0038] Referring to Figures 2 and 3, the length direction of the lifting plate 2 is parallel to the conveying direction of the cigarette box cardboard 9. In use, the lifting plate 2 is located above the conveyor belt in the inspection machine 10. Even if the cigarette box cardboard 9 is inspected and first conveyed to the lifting plate 2 and then falls onto the conveyor belt, in order to prevent the cigarette box cardboard 9 from hitting one end of the lifting plate 2 in the length direction during the process of conveying the cigarette box cardboard 9 to the lifting plate 2, guide arc surfaces 3 are formed at both ends of the lifting plate 2 in the length direction, and the ends of the guide arc surfaces 3 extend inclinedly toward the upper surface of the conveyor belt.
[0039] The implementation principle of this application embodiment is as follows: In use, the support frame 1 and the lifting plate 2 are first installed on the inspection machine 10, and both lifting plates 2 are positioned above the conveyor belt. The distance between the two lifting plates 2 is less than the width of the cigarette box cardboard 9. That is, when the cigarette box cardboard 9 is inspected by the inspection machine 10 and conveyed out, it first falls onto the lifting plate 2. Under the guidance of the lifting plate 2, the front cigarette box cardboard 9 falls directly onto the conveyor belt, while the rear cigarette box cardboard 9 falls from above the front cigarette box cardboard 9 until part of the rear cigarette box cardboard 9 overlaps the front cigarette box cardboard 9. As the rear cigarette box cardboard 9 continues to move, it ensures that the cigarette box cardboard 9 is re-stacking. By folding the cigarette box cardboard 9 into a fish-scale pattern, the situation where the rear end of the cigarette box cardboard 9 hits the front end of the cigarette box cardboard 9 is avoided. When the lifting plate 2 is not needed, such as when the front fold 97 of the cigarette box cardboard 9 faces the transmission direction, one fixing bolt 12 can be removed, the other fixing bolt 12 can be loosened, and then the support frame 1 and the lifting plate 2 can be rotated 180 degrees so that the lifting plate 2 is positioned away from the conveyor belt, thus achieving the purpose of storing the lifting plate 2 without removing the support frame 1. When the lifting plate 2 needs to be used, simply rotate the lifting plate 2 to be positioned above the conveyor belt and then tighten the two fixing bolts 12 again, making it more convenient to use.
[0040] Example 2:
[0041] Referring to Figures 4 and 5, the difference between this embodiment and Embodiment 1 is that the support frame 1 includes a base plate 13, a vertical plate 14, and a sliding folding plate 15. The base plate 13 is placed horizontally on the inspection machine 10. The vertical plate 14 is integrally formed with the base plate 13 and is perpendicular to the base plate 13. The first waist-shaped hole 11 and the fixing bolt 12 are provided on the base plate 13. One end of the sliding folding plate 15 is slidably engaged with the vertical plate 14, and the other end of the sliding folding plate 15 is connected to the lifting plate 2. The sliding folding plate 15 can slide along the height direction of the inspection machine 10 to adjust the height difference between the lifting plate 2 and the upper surface of the conveyor belt. A positioning structure 4 is also provided on the vertical plate 14 to fix the position of the sliding folding plate 15 after it slides.
[0042] Referring to Figures 4 and 5, the positioning structure 4 includes a clamping bolt 41 and a clamping nut 42. A second oblong hole 141 is provided on the vertical plate 14, and the length direction of the second oblong hole 141 is parallel to the height direction of the vertical plate 14. A through hole is provided on the sliding folding plate 15. The nut of the clamping bolt 41 abuts against the side wall of the vertical plate 14. One end of the clamping bolt 41 passes through the second oblong hole 141 and the through hole and is threadedly connected to the clamping nut 42. That is, in use, by tightening the clamping nut 42, the sliding folding plate 15 can be positioned on the vertical plate 14 with the cooperation of the clamping nut 42 and the nut of the clamping bolt 41. When it is necessary to adjust the height of the sliding folding plate 15, simply tighten the clamping nut 42 to loosen it, and then the sliding folding plate 15 can be slid. After the adjustment is completed, tighten the clamping nut 42 again so that the clamping nut 42 abuts against the vertical plate 14.
[0043] Referring to Figures 4 and 5, an insert plate 5 is integrally formed at the end of the sliding folding plate 15 away from the vertical plate 14. A U-shaped block 6 is welded and fixed to the bottom wall of the lifting plate 2, forming a slot between the U-shaped block 6 and the lifting plate 2. The insert plate 5 and the slot form a sliding fit. An adjustment structure 7 is also provided on the vertical plate 14. The adjustment structure 7 is used to adjust the distance between the lifting plate 2 and the sliding folding plate 15, thereby changing the distance between the two lifting plates 2 to adapt to cigarette box cardboard 9 of different widths.
[0044] Referring to Figures 4 and 5, a connecting block 8 is welded and fixed to the U-shaped block 6. A third oblong hole 81 is provided on the connecting block 8. The length direction of the third oblong hole 81 is parallel to the height direction of the connecting block 8. The adjusting structure 7 includes an adjusting screw 71 and a clamping nut 72. The axial direction of the adjusting screw 71 is parallel to the width direction of the cigarette box cardboard 9. One end of the adjusting screw 71 is located on one side of the vertical plate 14, and the other end of the adjusting screw 71 passes through the vertical plate 14 and the third oblong hole 81. The adjusting screw is threadedly engaged with the vertical plate 14. There are two clamping nuts 72. Both clamping nuts 72 are threadedly engaged with the adjusting screw 71, and the two clamping nuts 72 abut against the two sides of the connecting block 8 respectively.
[0045] Referring to Figures 4 and 5, during use, the adjusting screw 71 is rotated to move along its own axis, thereby adjusting the position of the lifting plate 2 with the cooperation of the two clamping nuts 72. At the same time, the setting of the third oblong hole 81 prevents the adjusting screw 71 from affecting the adjustment of the height position of the sliding folding plate 15. In addition, a rotating head 73 is formed at the end of the adjusting screw 71 away from the connecting block 8, and friction texture is formed on the outer wall of the rotating head 73. During use, the user rotates the adjusting screw 71 by rotating the rotating head 73, making the overall use more convenient.
[0046] The implementation principle of this application embodiment is as follows: In use, the support frame 1 and the lifting plate 2 are first installed on the inspection machine 10, and both lifting plates 2 are positioned above the conveyor belt. Then, the position of the lifting plates 2 is changed by turning the adjusting screw 71 so that the distance between the two lifting plates 2 is less than the width of the cigarette box cardboard 9. This ensures that when the cigarette box cardboard 9 is inspected by the inspection machine 10 and conveyed out, it can fall smoothly onto the lifting plate 2. Then, the setting height of the lifting plate 2 is adjusted by the positioning structure 4 to ensure that the cigarette box cardboard 9 will not collide with anything when it falls from the lifting plate 2 onto the conveyor belt. The front and rear cigarette box cardboard 9 are then processed by the inspection machine 10, which then inspects and transmits the cigarette box cardboard 9. During transmission, guided by the lifting plate 2, the front cigarette box cardboard 9 falls directly onto the conveyor belt, while the rear cigarette box cardboard 9 falls from above the front cigarette box cardboard 9 until part of the rear cigarette box cardboard 9 overlaps the front cigarette box cardboard 9. As the rear cigarette box cardboard 9 continues to transmit, while ensuring that the cigarette box cardboard 9 is re-stacked into a fish scale shape, the situation where the end of the rear cigarette box cardboard 9 hits the front cigarette box cardboard 9 is also avoided.
[0047] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.
Claims
1. An auxiliary device for a cigarette box packaging cardboard inspection machine, characterized in that: It includes two support frames (1) set on the inspection machine (10), the two support frames (1) are arranged symmetrically, and the support frames (1) are provided with a lifting plate (2) for raising and guiding the conveying direction of the cigarette box cardboard (9), the lifting plate (2) is located above the conveyor belt in the inspection machine (10).
2. The auxiliary device for a cigarette box packaging cardboard inspection machine according to claim 1, characterized in that: The lifting plate (2) is provided with guide arc surfaces (3) at both ends along the conveying direction of the cigarette box cardboard (9), and the guide arc surfaces (3) extend toward the upper surface of the conveyor belt of the inspection machine (10).
3. The auxiliary device for a cigarette box packaging cardboard inspection machine according to claim 1, characterized in that: The support frame (1) is provided with a first waist-shaped hole (11), the length direction of the first waist-shaped hole (11) is parallel to the conveying direction of the cigarette box cardboard (9), and the support frame (1) is also provided with a fixing bolt (12), one end of the fixing bolt (12) passes through the first waist-shaped hole (11) and is threaded onto the inspection machine (10).
4. The auxiliary device for a cigarette box packaging cardboard inspection machine according to claim 1, characterized in that: The support frame (1) includes a base plate (13), a vertical plate (14) fixed on the base plate (13), and a sliding folding plate (15) slidably disposed on the vertical plate (14). The sliding direction of the sliding folding plate (15) is parallel to the height direction of the inspection machine (10). The vertical plate (14) is provided with a positioning structure (4) for positioning the sliding folding plate (15). The lifting plate (2) is disposed on the sliding folding plate (15).
5. The auxiliary device for a cigarette box packaging cardboard inspection machine according to claim 4, characterized in that: The positioning structure (4) includes a clamping bolt (41) provided on the vertical plate (14) and a clamping nut (42) threadedly engaged with the clamping bolt (41). The vertical plate (14) has a second waist-shaped hole (141) with the length direction of the second waist-shaped hole (141) parallel to the sliding direction of the sliding folding plate (15). The sliding folding plate (15) has a through hole. One end of the clamping bolt (41) passes through the second waist-shaped hole (141) and the through hole and is connected to the clamping nut (42).
6. A device according to claim 4, characterized in that: The sliding folding plate (15) is fixed with a plug plate (5) at one end away from the vertical plate (14). A U-shaped block (6) is fixed on the lifting plate (2). A slot is formed between the U-shaped block (6) and the lifting plate (2). The plug plate (5) and the slot slide into each other. An adjustment structure (7) for adjusting the distance between the lifting plate (2) and the sliding folding plate (15) is also provided on the vertical plate (14).
7. The auxiliary device for a cigarette box packaging cardboard inspection machine according to claim 6, characterized in that: The adjustment structure (7) includes an adjustment screw (71) threaded onto the vertical plate (14) and two clamping nuts (72) threadedly engaged with the adjustment screw (71). A connecting block (8) is fixed on the U-shaped block (6). A third waist-shaped hole (81) is provided on the connecting block (8). The length direction of the third waist-shaped hole (81) is parallel to the length direction of the second waist-shaped hole (141). One end of the adjustment screw (71) is located on one side of the vertical plate (14), and the other end of the adjustment screw (71) passes through the third waist-shaped hole (81). The two clamping nuts (72) clamp the connecting block (8).
8. The auxiliary device for a cigarette box packaging cardboard inspection machine according to claim 7, characterized in that: The adjusting screw (71) is provided with a rotating head (73) at the end away from the connecting block (8) to facilitate the user to rotate the adjusting screw (71), and the rotating head (73) is provided with friction texture.