A video surveillance processing device for smart construction sites

Abstract

The present invention belongs to the field of video surveillance technology, and specifically discloses a video surveillance processing device for a smart construction site, comprising a mounting shell, a monitor mounted inside the mounting shell, a transparent cover mounted at the front end of the mounting shell, a scraping mechanism provided at the front end of the mounting shell, a heat dissipation mechanism provided at the rear end of the bottom of the mounting shell, a driving mechanism mounted on the top of the mounting shell, an auxiliary mechanism provided at the bottom end of the mounting shell, and the driving mechanism cooperating with the auxiliary mechanism. The present invention can clean the transparent cover and the heat dissipation mechanism through the cooperation of the driving mechanism and the auxiliary mechanism, on the one hand ensuring that the transparent cover continuously maintains good light transmittance, and on the other hand cleaning the heat dissipation mechanism can ensure that the heat dissipation channel is unobstructed, thereby improving heat dissipation efficiency.

Description

Technical Field

[0001] The present invention belongs to the technical field of video surveillance, and specifically discloses a video surveillance processing device for a smart construction site. Background Art

[0002] A video surveillance system is a set of systems consisting of cameras, video recording equipment, monitors, network equipment and related software. It is used to monitor, record and manage video images and data of specific areas or places in real time. It is commonly used in security monitoring, anti-theft, traffic supervision, employee supervision, public safety and other fields.

[0003] The existing video surveillance processing equipment for smart construction sites is easily contaminated by dust, water stains and other stains in the harsh environment of the construction site. The transparent cover of the monitoring equipment is easily contaminated by dust, water stains and other stains, resulting in blurred monitoring images. In addition, the monitor will generate a lot of heat during long-term operation. The existing heat dissipation structure is easily blocked by dust and debris, affecting the heat dissipation effect. Summary of the Invention

[0004] In view of this, the purpose of the present invention is to propose a video surveillance processing device for smart construction sites to solve the problem that in the harsh environment of the construction site, the transparent cover of the existing monitoring equipment is easily contaminated with dust, water stains and other stains, resulting in blurred monitoring images, and the monitor will generate a lot of heat during long-term operation, and the existing heat dissipation structure is easily blocked by dust and debris, affecting the heat dissipation effect.

[0005] To achieve the above objectives, the present invention provides a video surveillance processing device for a smart construction site, comprising a mounting shell, a monitor installed inside the mounting shell, a transparent cover installed at the front end of the mounting shell, a scraping mechanism provided at the front end of the mounting shell, the scraping mechanism being used to clean the surface of the transparent cover, a heat dissipation mechanism provided at the rear end of the bottom of the mounting shell, the heat dissipation mechanism being used to dissipate heat from the monitor, a driving mechanism installed at the top of the mounting shell, an auxiliary mechanism provided at the bottom end of the mounting shell, the driving mechanism cooperating with the auxiliary mechanism, and the cooperation between the driving mechanism and the auxiliary mechanism can clean the transparent cover and the heat dissipation mechanism.

[0006] In the above technical solution, preferably, a protective cover is provided on the outside of the mounting shell, the mounting shell is installed inside the protective cover, a fixing plate is provided on the top of the mounting shell, a connecting column is installed on the top of the fixing plate by bolts, and the connecting column is fixedly connected to the protective cover, and circular holes are provided at the rear end of the mounting shell and the rear end of the protective cover, and the circular holes are used for installing cables.

[0007] In the above technical solution, preferably, the scraping mechanism includes a scraping plate, which is movably arranged at the front end of the mounting shell, and rectangular blocks are fixedly installed at both ends of the scraping plate. A vertical slide groove is provided on the inner wall of the protective cover, and the other end of the rectangular block is slidably installed in the vertical slide groove, and a rectangular plate is fixedly provided on the top of the rectangular block.

[0008] In the above technical solution, preferably, the scraper plate is set to an inclined state as a whole, and the horizontal height of the front end of the scraper plate is lower than the horizontal height of the rear end of the scraper plate, and the rear end of the scraper plate corresponds to the surface of the transparent cover.

[0009] In the above technical solution, preferably, the heat dissipation mechanism includes a heat dissipation bin, which is fixedly installed on the bottom of the mounting shell, and a curved cover plate is movably provided on the bottom of the heat dissipation bin, and a dustproof net is provided on the surface of the curved cover plate, and an L-shaped positioning plate is fixedly installed on the side of the curved cover plate, and a T-shaped slider is provided on the surface of the L-shaped positioning plate, and a mating groove is provided on the side of the heat dissipation bin, and the surface of the T-shaped slider is slidably installed in the mating groove.

[0010] In the above technical solution, preferably, the driving mechanism includes a sliding block, a parallel sliding groove is provided on the top of the mounting shell, a protrusion is provided at the bottom of the sliding block, and the protrusion is slidably installed in the parallel sliding groove, a cylinder is provided on the top of the mounting shell, the output end of the cylinder is connected to the sliding block, and side blocks are fixedly installed on both sides of the sliding block, the front end of the side block surface is installed with a first connecting strip through a rotating shaft, the other end of the first connecting strip is connected to the rectangular plate through a rotating shaft, and the rear end of the side block surface is installed with a second connecting strip through a bolt, and the other end of the second connecting strip is connected to the L-shaped positioning plate through a bolt.

[0011] In the above technical solution, preferably, a positioning groove is provided at the front end inside the mounting shell, and the surface of the transparent cover is movably engaged in the positioning groove. The auxiliary mechanism includes a light rod, and the light rod is located at the bottom end inside the mounting shell. A fourth gear is installed at the front end of the light rod, and an annular rack is provided on the end face of the transparent cover on the inner side of the mounting shell. The fourth gear is engaged with the annular rack, and the tail end of the light rod passes through the mounting shell. A cleaning disk is installed at the tail end of the light rod by bolts, and the cleaning disk corresponds to the arc-shaped cover plate.

[0012] In the above technical solution, preferably, a protective frame is installed at the bottom of the mounting shell, a stepper motor is installed inside the protective frame, the output end of the stepper motor is connected to the first gear, a third gear is provided on the surface of the optical rod, a through slot is provided at the bottom of the mounting shell and directly below the third gear, a second gear is rotatably installed inside the through slot, and the upper and lower parts of the second gear are respectively engaged with the third gear and the first gear.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] By setting up a scraping mechanism, the rectangular block moves upward along the vertical slide, and the rear end of the scraper can contact the surface of the transparent cover to clean the surface of the transparent cover. It can promptly remove dust, stains, etc. that may be contaminated on the surface of the transparent cover to avoid affecting the shooting field of view of the monitor, thereby ensuring the clarity of the monitoring image and facilitating accurate and effective monitoring of the on-site conditions of the construction site;

[0015] By setting up a heat dissipation mechanism, the monitor can be cooled, which can effectively reduce the heat generated by the monitor during operation, prevent the monitor's performance and life from being affected by excessive temperature, ensure the stable operation of the equipment, and reduce the probability of failure caused by overheating;

[0016] By setting up a driving mechanism, the extension and contraction of the cylinder can accurately control the movement of the sliding block, thereby accurately controlling the rising height of the scraper plate and the moving distance of the arc cover plate, which can ensure that the scraper plate can cover the area that needs to be cleaned when cleaning the transparent cover, and at the same time the arc cover plate can be fully opened;

[0017] Under the action of the auxiliary mechanism, the transparent cover will rotate so that all parts of the surface of the transparent cover can be scraped by the scraper to avoid cleaning dead corners. At the same time, the cleaning disc will also rotate. The cleaning disc can clean the surface of the curved cover to remove dust and other debris, ensure that the dustproof net on the curved cover is ventilated smoothly, and improve the heat dissipation efficiency of the heat dissipation mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0019] Figure 2 This is a schematic diagram of the overall structure of the present invention from another perspective;

[0020] Figure 3 This is a schematic diagram of the mounting shell structure of the present invention;

[0021] Figure 4 Schematic diagram of the driving mechanism structure of the present invention;

[0022] Figure 5 This is a schematic diagram of the housing structure installed from another perspective of the present invention;

[0023] Figure 6 For the present invention Figure 3 Enlarged view of point A in the middle;

[0024] Figure 7 For the present invention Figure 5 Enlarged view of point B in the middle;

[0025] Figure 8 This is a schematic diagram of the internal structure of the mounting housing of the present invention;

[0026] Figure 9 For the present invention Figure 8 Enlarged view of point C in the middle.

[0027] In the figure: 1. Mounting shell; 2. Protective cover; 3. Fixing plate; 4. Connecting column; 5. Transparent cover; 6. Driving mechanism; 7. Scraping mechanism; 8. Heat dissipation mechanism; 9. Auxiliary mechanism; 10. Parallel slide; 11. Sliding block; 12. Side block; 13. First connecting strip; 14. Second connecting strip; 15. Vertical slide; 16. Rectangular block; 17. Rectangular plate; 18. Scraping plate; 19. Heat dissipation bin; 20. Arc cover; 21. L-shaped positioning plate; 22. Protective frame; 23. Stepping motor; 24. First gear; 25. Second gear; 26. Polished rod; 27. Third gear; 28. Fourth gear; 29. ​​Annular rack; 30. Positioning groove; 31. Cleaning disc; 32. T-shaped slider; 33. Matching slide; 34. Cylinder. DETAILED DESCRIPTION

[0028] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0029] In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0030] like Figures 1-9The video surveillance processing equipment for a smart construction site shown in the figure includes a mounting shell 1, a monitor is mounted inside the mounting shell 1, a transparent cover 5 is mounted on the front end of the mounting shell 1, a scraping mechanism 7 is provided on the front end of the mounting shell 1, the scraping mechanism 7 is used to clean the surface of the transparent cover 5, a heat dissipation mechanism 8 is provided on the rear end of the bottom of the mounting shell 1, the heat dissipation mechanism 8 is used to dissipate heat from the monitor, a driving mechanism 6 is mounted on the top of the mounting shell 1, an auxiliary mechanism 9 is provided on the bottom end of the mounting shell 1, the driving mechanism 6 cooperates with the auxiliary mechanism 9, and the cooperation between the driving mechanism 6 and the auxiliary mechanism 9 can The transparent cover 5 and the heat dissipation mechanism 8 are cleaned. The scraping mechanism 7 can be lifted upward by the driving mechanism 6, and the arc-shaped cover plate 20 inside the heat dissipation mechanism 8 will also be pushed backward. Under the action of the auxiliary mechanism 9, the light rod 26 will simultaneously drive the transparent cover 5 and the cleaning disk 31 to rotate. The rotation of the transparent cover 5 allows all parts of the surface of the transparent cover 5 to be scraped by the scraping plate 18, avoiding cleaning dead corners. The rotation of the cleaning disk 31 can clean the surface of the arc-shaped cover plate 20, remove dust and other debris, ensure that the dustproof net on the arc-shaped cover plate 20 is ventilated smoothly, and improve the heat dissipation efficiency of the heat dissipation mechanism 8.

[0031] The top of the mounting shell 1 is provided with a fixing plate 3, and the top of the fixing plate 3 is provided with a connecting column 4 by bolts. The connecting column 4 is fixedly connected to the protective cover 2. The connecting column 4 is installed by bolts on the top of the fixing plate 3, thereby fixing the mounting shell 1 and the protective cover 2. This structure makes the installation process relatively simple, and the connection is firm and stable, which is convenient for the installation and arrangement of the entire equipment on the construction site. The rear end of the mounting shell 1 and the rear end of the protective cover 2 are both provided with circular holes. The circular holes are used for the installation of cables. The circular holes provide a special channel for the access and arrangement of cables. The cables can be connected to the monitor inside the mounting shell 1, which is convenient for subsequent maintenance and management. At the same time, it can also prevent the cables from being accidentally pulled or damaged due to random placement to a certain extent.

[0032] The scraping mechanism 7 includes a scraping plate 18, which is movably arranged at the front end of the mounting shell 1, and rectangular blocks 16 are fixedly installed at both ends of the scraping plate 18. A vertical slide groove 15 is provided on the inner wall of the protective cover 2, and the other end of the rectangular block 16 is slidably installed in the vertical slide groove 15. A rectangular plate 17 is fixedly provided on the top of the rectangular block 16, and the rectangular block 16 moves upward along the vertical slide groove 15. The rear end of the scraping plate 18 can contact the surface of the transparent cover 5. At the same time, the rectangular block 16 and the vertical slide groove 15 also provide a stable guiding effect for the up and down movement of the scraping plate 18. The scraping plate 18 is movably arranged at the front end of the mounting shell 1, and can directly clean the surface of the transparent cover 5, effectively remove dust, water stains and other stains, and maintain the clarity of the transparent cover 5.

[0033] The scraper plate 18 is arranged as a whole in an inclined state, and the horizontal height of the front end of the scraper plate 18 is lower than the horizontal height of the rear end of the scraper plate 18. The rear end of the scraper plate 18 corresponds to the surface of the transparent cover 5, and the horizontal height of the front end of the scraper plate 18 is lower than the rear end. When scraping water stains, dust and other impurities on the surface of the transparent cover 5, the scraped impurities will fall quickly along the inclined scraper plate 18 due to gravity, and will not accumulate between the scraper plate 18 and the transparent cover 5, thereby avoiding secondary contamination of the transparent cover 5, improving the cleaning efficiency and quality, and more effectively keeping the transparent cover 5 clear.

[0034] The heat dissipation mechanism 8 includes a heat dissipation chamber 19, which is fixedly mounted on the bottom of the mounting shell 1. The heat dissipation chamber 19 provides a special heat dissipation space for the monitor to ensure that the heat generated by the monitor can be dissipated in time, to prevent the equipment from being degraded or even damaged due to overheating, and to extend the service life of the equipment. The bottom of the heat dissipation chamber 19 is movably provided with an arc-shaped cover plate 20, the surface of the arc-shaped cover plate 20 is provided with a dustproof net, the side of the arc-shaped cover plate 20 is fixedly mounted with an L-shaped positioning plate 21, the surface of the L-shaped positioning plate 21 is provided with a T-shaped slider 32, and the heat dissipation chamber 19 is provided with a T-shaped slider 32. A matching groove 33 is provided on the side of the heat storage bin 19, and the surface of the T-shaped slider 32 is slidably installed in the matching groove 33. The dustproof net on the surface of the arc cover 20 can effectively prevent dust, debris, etc. from entering the heat dissipation bin 19, avoiding dust accumulation on the monitor or heat dissipation components to affect the heat dissipation effect, and also preventing debris from causing physical damage to internal components. At the same time, the arc cover 20 is slidably connected to the matching groove 33 on the side of the heat dissipation bin 19 through the T-shaped slider 32 on the L-shaped positioning plate 21, so that the arc cover 20 can move flexibly.

[0035] The driving mechanism 6 includes a sliding block 11, a parallel slide groove 10 is provided on the top of the mounting shell 1, a protrusion is provided at the bottom of the sliding block 11, and the protrusion is slidably installed in the parallel slide groove 10, and a cylinder 34 is provided on the top of the mounting shell 1, and the output end of the cylinder 34 is connected to the sliding block 11. Side blocks 12 are fixedly installed on both sides of the sliding block 11, and the front end of the surface of the side block 12 is installed with a first connecting bar 13 through a rotating shaft, and the other end of the first connecting bar 13 is connected to the rectangular plate 17 through a rotating shaft, and the rear end of the surface of the side block 12 is installed with a second connecting bar 14 through a bolt, and the other end of the second connecting bar 14 is connected to the L-shaped positioning plate 21 through a bolt. The extension and contraction of the cylinder 34 can accurately control the sliding block 11 in the parallel slide groove 10 Sliding, the movement of the sliding block 11 can drive the side block 12, the first connecting bar 13, the rectangular plate 17 and the second connecting bar 14, and the L-shaped positioning plate 21 to move in sequence. When the sliding block 11 moves toward the rear of the mounting shell 1, the first connecting bar 13 will pull the rectangular plate 17, so that the rectangular block 16 moves upward along the vertical slide groove 15, thereby realizing the automatic cleaning of the surface of the transparent cover 5 by the scraping plate 18 of the scraping mechanism 7. At the same time, the second connecting bar 14 will push the L-shaped positioning plate 21 to move toward the rear of the mounting shell 1, and the arc-shaped cover plate 20 will also move toward the rear of the mounting shell 1 synchronously, thereby realizing the automatic opening of the arc-shaped cover plate 20 of the heat dissipation mechanism 8, without the need for manual operation, which greatly improves the efficiency and convenience of cleaning and heat dissipation adjustment.

[0036] A positioning groove 30 is provided at the front end of the interior of the mounting shell 1, and the surface of the transparent cover 5 is movably snapped into the positioning groove 30. The positioning groove 30 can accurately define the installation position of the transparent cover 5, ensure that its relative position with the monitor is accurate, and make the monitoring field of view stable. The auxiliary mechanism 9 includes a light rod 26, and the light rod 26 is at the bottom end of the interior of the mounting shell 1. A fourth gear 28 is installed at the front end of the light rod 26, and an annular rack 29 is provided on the end surface of the transparent cover 5 on the inner side of the mounting shell 1. The fourth gear 28 is meshed with the annular rack 29. The tail end of the light rod 26 passes through the mounting shell 1, and a cleaning disk 31 is installed at the tail end of the light rod 26 by bolts. The cleaning disk 31 corresponds to the arc cover 20, and the fourth gear 28 at the front end of the light rod 26 in the auxiliary mechanism 9 is in contact with the interior of the transparent cover 5. The annular rack 29 on the side end face is engaged. When the optical rod 26 rotates, it can drive the transparent cover 5 to rotate. This rotation allows all parts of the surface of the transparent cover 5 to have the opportunity to be scraped by the scraping plate 18 of the scraping mechanism 7, avoiding cleaning dead corners, improving the cleaning effect of the surface of the transparent cover 5, and ensuring the clarity of the monitoring screen. The cleaning disk 31 at the tail end of the optical rod 26 corresponds to the arc-shaped cover plate 20. When the optical rod 26 rotates, the cleaning disk 31 also rotates accordingly. Since the arc-shaped cover plate 20 moves toward the rear of the mounting shell 1 as a whole, the cleaning disk 31 can clean the surface of the arc-shaped cover plate 20, remove dust and other debris on the surface of the arc-shaped cover plate 20, and ensure that the dustproof net on the arc-shaped cover plate 20 is smoothly ventilated, thereby improving the heat dissipation efficiency of the heat dissipation mechanism 8.

[0037] A protective frame 22 is installed at the bottom of the mounting shell 1, and a stepping motor 23 is installed inside the protective frame 22. The output end of the stepping motor 23 is connected to the first gear 24, and a third gear 27 is provided on the surface of the optical rod 26. A through slot is provided at the bottom of the mounting shell 1 and directly below the third gear 27. A second gear 25 is rotatably installed inside the through slot. The upper and lower parts of the second gear 25 are respectively meshed with the third gear 27 and the first gear 24. The stepping motor 23 is used as the power source, and the first gear 24, the second gear 25 and the third gear 27 are arranged and meshed, providing precise control for the rotation of the optical rod 26, ensuring that the rotation speed and angle of the transparent cover 5 meet the cleaning requirements, and the cleaning frequency and strength of the cleaning disc 31 on the arc cover 20 are stable.

[0038] Working principle: First, install the connecting column 4 through the bolts on the top of the fixing plate 3 to fix the mounting shell 1 and the protective cover 2, install the monitor inside the mounting shell 1, and connect the cable to the monitor through the circular holes at the rear end of the mounting shell 1 and the protective cover 2 to complete the installation and layout of the entire equipment on the construction site. Then the stepper motor 23 at the bottom of the mounting shell 1 is started, and the first gear 24 connected to the output end of the stepper motor 23 rotates, and through the engagement with the second gear 25 and the third gear 27, the light rod 26 is driven to rotate. The fourth gear 28 at the front end of the light rod 26 engages with the annular rack 29 on the inner end face of the transparent cover 5, causing the transparent cover 5 to rotate. At the same time, the cleaning disk 31 at the tail end of the light rod 26 also rotates accordingly. Then the cylinder 34 is started, and the sliding block 11 will move to the rear of the mounting shell 1. The first connecting bar 13 at the front end of the surface of the side block 12 will pull the rectangular plate 17, causing the rectangular block 16 to move upward along the vertical slide groove 15, driving the scraper plate 18 The rotation of the cleaning disc 31 can clean the surface of the curved cover plate 20 moving toward the rear of the installation shell 1, remove dust and other debris, ensure that the dustproof net on the curved cover plate 20 is ventilated smoothly, and improve the heat dissipation efficiency of the heat dissipation mechanism 8.

[0039] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only describe the principles of the present invention. Various changes and improvements are possible without departing from the spirit and scope of the present invention, and such changes and improvements fall within the scope of the invention as claimed.

Claims

1. A video surveillance processing device for a smart construction site, comprising a mounting housing, characterized in that: The top of the mounting shell is provided with a driving mechanism, and the bottom end of the mounting shell is provided with an auxiliary mechanism, and the driving mechanism cooperates with the auxiliary mechanism, and the driving mechanism and the auxiliary mechanism can clean the transparent cover and the heat dissipation mechanism; the driving mechanism includes a sliding block, the top of the mounting shell is provided with a parallel slide groove, the bottom of the sliding block is provided with a protrusion, and the protrusion is slidably installed in the parallel slide groove, and the top of the mounting shell is provided with a cylinder, the output end of the cylinder is connected to the sliding block, and side blocks are fixedly installed on both sides of the sliding block, the front end of the side block surface is provided with a first connecting bar through a rotating shaft, and the rear end of the side block surface is provided with a second connecting bar through a bolt, and the other end of the second connecting bar is connected to the L-shaped positioning plate through a bolt; The scraping mechanism includes a scraping plate, which is movably arranged at the front end of the mounting shell. Rectangular blocks are fixedly installed at both ends of the scraping plate, and a rectangular plate is fixedly installed on the top of the rectangular block. The scraping plate is set in an inclined state as a whole, and the horizontal height of the front end of the scraping plate is lower than the horizontal height of the rear end of the scraping plate. The rear end of the scraping plate corresponds to the surface of the transparent cover.

2. The video surveillance processing equipment for a smart construction site according to claim 1, characterized in that: A protective cover is provided on the outside of the mounting shell, and the mounting shell is installed inside the protective cover. A fixing plate is provided on the top of the mounting shell, and a connecting column is installed on the top of the fixing plate by bolts. The connecting column is fixedly connected to the protective cover. Circular holes are provided at the rear end of the mounting shell and the rear end of the protective cover, and the circular holes are used for installing cables.

3. The video monitoring processing equipment for a smart construction site according to claim 2, characterized in that: A vertical sliding groove is provided on the inner wall of the protective cover, and the other end of the rectangular block is slidably installed in the vertical sliding groove.

4. The video surveillance processing equipment for a smart construction site according to claim 3, characterized in that: The heat dissipation mechanism includes a heat dissipation bin, which is fixedly installed at the bottom of the mounting shell. An arc-shaped cover is movably provided at the bottom of the heat dissipation bin, a dust-proof net is provided on the surface of the arc-shaped cover, an L-shaped positioning plate is fixedly installed on the side of the arc-shaped cover, a T-shaped slider is provided on the surface of the L-shaped positioning plate, a matching groove is provided on the side of the heat dissipation bin, and the surface of the T-shaped slider is slidably installed in the matching groove.

5. The video surveillance processing equipment for a smart construction site according to claim 4, characterized in that: A positioning groove is provided at the front end of the interior of the mounting shell, and the surface of the transparent cover is movably engaged in the positioning groove. The auxiliary mechanism includes a polished rod, which is located at the bottom end of the interior of the mounting shell. A fourth gear is installed at the front end of the polished rod, and an annular rack is provided on the end face of the transparent cover on the inner side of the mounting shell. The fourth gear is engaged with the annular rack. The tail end of the polished rod passes through the mounting shell, and a cleaning disk is installed at the tail end of the polished rod by a bolt, and the cleaning disk corresponds to the arc-shaped cover plate.

6. The video surveillance processing equipment for a smart construction site according to claim 5, characterized in that: A protective frame is installed at the bottom of the mounting shell, and a stepper motor is installed inside the protective frame. The output end of the stepper motor is connected to the first gear, and a third gear is provided on the surface of the polished rod. A through slot is provided at the bottom of the mounting shell and directly below the third gear, and a second gear is rotatably installed inside the through slot. The upper and lower parts of the second gear are respectively engaged with the third gear and the first gear.

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