Quick-installation anti-loosening device for electromechanical installation pipelines

Abstract

This invention relates to the field of pipeline fixing technology and discloses a quick-installation anti-loosening device for electromechanical pipelines. The device includes two pipeline fixing units arranged vertically opposite each other. Each unit includes a mounting frame with two positioning slots and two guide rods fixed thereon. Several slidable fixing components are mounted on the guide rods. Positioning components are also provided on the mounting frame to fix the positions of these components, and a control component is provided to control the positioning components. This invention achieves this by adjusting the position of the upper mounting frame to stagger the upper and lower mounting frames, and then pulling a push block according to the pipeline position. Through a series of linkages, the positioning plate separates from the slider, allowing the slider to move freely. This enables flexible adjustment of the tube bundle cover position, achieving constraint and fixing of pipelines with different spacing.

Description

Technical Field

[0001] This invention relates to the field of pipeline fixing technology, and in particular to a quick-installation anti-loosening device for electromechanical installation pipelines. Background Technology

[0002] The electromechanical installation pipeline quick installation anti-loosening device is a device used in the pipeline installation field that enables rapid installation of pipelines and prevents them from becoming loose.

[0003] A search revealed that Chinese patent CN206206801U discloses a pipeline fixing bracket, including a bracket base and a fixing plate. The bracket base has a groove for placing pipelines, and the fixing plate is detachably connected to the bracket base to fix the pipelines placed in the groove. The bracket base is fixedly connected to the wall, and the pipelines are placed in the groove of the bracket base. This solution eliminates the need for fixing to external scaffolding, structural holes, etc., and is simple to manufacture, low in cost, convenient to use, and reusable. It solves the problem of integrated layout of water and electricity pipelines during building construction, achieving a safe and aesthetically pleasing effect. However, the above solution still has the following shortcomings in practical use:

[0004] The pipeline fixing structure proposed in the above scheme cannot flexibly adjust the spacing between pipelines. During the system layout phase, the deviation between the initial fixed spacing and the actual needs leads to frequent rework, which increases material consumption and delays the construction period. When pipelines are displaced due to thermal expansion and contraction or mechanical vibration, the fixed spacing cannot be adjusted adaptively, which may cause local stress concentration, accelerate the fatigue damage of the support or pipeline outer protective sleeve, and even cause the pipeline connection to loosen and leak. When the equipment is maintained or upgraded, if new pipelines are added or the pipe diameter is changed, the original fixing structure may be incompatible due to the fixed spacing, forcing the construction personnel to destroy the original structure and reinstall it. This not only increases the renovation cost, but may also lead to a chaotic pipeline layout due to space constraints, affecting the overall heat dissipation efficiency and the accessibility of maintenance channels.

[0005] Therefore, a new pipeline fixing and anti-loosening device needs to be designed to solve the above problems. Summary of the Invention

[0006] The purpose of this invention is to address the shortcomings of existing technologies by proposing a quick-installation anti-loosening device for electromechanical installation pipelines.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] A quick-installation anti-loosening device for electromechanical installation pipelines includes two pipeline fixing units, which are arranged vertically opposite each other. Each pipeline fixing unit includes a mounting frame with two positioning slots and two guide rods fixed on it. Several slidable fixing components are provided on the two guide rods. A positioning component is provided on the mounting frame to fix the position of the fixing components. A control component is provided on the mounting frame to control the positioning component.

[0009] The fixing assembly includes a bundle tube cover, on which airbags are fixed. Two adjacent airbags are connected by a connecting tube. The mounting frame is provided with an air extraction assembly for extracting gas from several of the airbags. The air extraction assembly includes a pull rod and a crossbar.

[0010] The mounting bracket is equipped with a pulling component for driving the air extraction component and the control component. The pulling component includes a push block, which is fixed to the end of the pull rod away from the crossbar. The push block has a mounting groove and a threaded opening, and the mounting groove and the threaded opening are connected. A movable clamping block is provided inside the mounting groove. An adjusting screw is threaded into the threaded opening, and one end of the adjusting screw is rotatably connected to the clamping block.

[0011] The two mounting brackets are connected by a connecting assembly.

[0012] As a preferred embodiment of the present invention, the fixing component further includes a slider, which is slidably sleeved on two guide rods, and the bottom surface of the slider is fixed with a plurality of first locking teeth, and the bundle tube cover is fixed on the top surface of the slider.

[0013] As a preferred embodiment of the present invention, the positioning assembly includes a positioning plate and two grooves. The top surface of the positioning plate is fixed with a plurality of second locking teeth, and the bottom surface of the positioning plate is fixed with two fixing rods. Both grooves are formed on the mounting frame, and the two fixing rods are respectively inserted into the two grooves. The positioning plate and the mounting frame are connected by two first springs.

[0014] As a preferred embodiment of the present invention, the control component includes a protrusion and a movable plate. The protrusion is fixed on the bottom surface of the positioning plate, and the movable plate is slidably mounted on the mounting frame. The movable plate is provided with an inclined surface and is positioned directly opposite the protrusion. The movable plate is connected to the mounting frame through a guide structure.

[0015] The guide structure includes two slide rods and two sliding sleeves. The two slide rods are fixed to the side of the mounting frame, and the two sliding sleeves are slidably sleeved on the two slide rods respectively. The movable plate is connected to the two sliding sleeves by two connecting rods.

[0016] As a preferred embodiment of the present invention, the air extraction assembly includes a sealing cylinder, which is fixed to the side of the mounting bracket. The sealing cylinder is connected to one of the airbags via an air pipe. A sliding plug is slidably connected inside the sealing cylinder. A crossbar is fixed to the side of the sliding plug. The end of the crossbar away from the sliding plug extends to the outside of the sealing cylinder. A pull rod is fixed to the end of the crossbar away from the sliding plug. A fixing block is fixed on the pull rod. The fixing block is connected to one of the sliding sleeves via a rod body.

[0017] As a preferred embodiment of the present invention, the clamping block is positioned directly opposite the mounting bracket, and the other end of the adjusting screw extends to the outside of the threaded opening.

[0018] As a preferred embodiment of the present invention, the two tube bundles facing each other vertically together form a tubular structure.

[0019] As a preferred embodiment of the present invention, the bottom surface of the positioning plate is provided with an avoidance groove that is adapted to the moving plate.

[0020] As a preferred embodiment of the present invention, the connecting assembly consists of a rotating structure and a clamping structure. The rotating structure includes a fixed cylinder and a connecting sleeve. The fixed cylinder is fixed on the mounting bracket at the lower end, and a vertical rod is fixed on the fixed cylinder. The connecting sleeve is fixed on the mounting bracket at the upper end, and the connecting sleeve is movably sleeved on the vertical rod. A limit cap is fixed at the end of the vertical rod away from the fixed cylinder.

[0021] As a preferred embodiment of the present invention, the clamping structure includes a rotating frame and a positioning block. The rotating frame is rotatably mounted on the upper mounting bracket. A movable plate is slidably disposed on the rotating frame. A slot is provided at the end of the movable plate away from the rotating frame. The shape of the slot is adapted to the shape of the positioning block. The rotating frame and the movable plate are connected by a tension spring.

[0022] The present invention has the following beneficial effects:

[0023] 1. By adjusting the position of the upper mounting bracket to stagger the upper and lower mounting brackets, and then pulling the push block according to the pipeline position, the positioning plate and the slider are separated through a series of linkages, and the slider can move freely, thereby flexibly adjusting the position of the bundle tube cover and realizing the constraint and fixation of pipelines with different spacing.

[0024] 2. After pulling the push block to a position away from the sealing cylinder, turn the adjusting screw. The clamping block will then be inserted into the corresponding positioning groove, thereby fixing the position of the pull rod, crossbar, slide plug and positioning plate. This makes it convenient for staff to adjust the bundle tube cover. The operation is simple and can ensure the stability of the component position during the adjustment process.

[0025] 3. After the installation frame is connected, the staff adjusts the position of the push block so that the positioning plate once again constrains the slider to fix the tube cover. At the same time, the sliding plug pushes the gas in the sealing cylinder back into the airbag, so that the airbag inflates and wraps around the pipeline. This can effectively fix pipelines of different diameters and prevent the pipeline from loosening or shaking. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the quick-installation anti-loosening device for electromechanical installation pipelines proposed in this invention. Figure 1 ;

[0027] Figure 2 This is a schematic diagram of the structure of the quick-installation anti-loosening device for electromechanical installation pipelines proposed in this invention. Figure 2 ;

[0028] Figure 3 This is a schematic diagram of the structure when two mounting brackets are staggered.

[0029] Figure 4 This is a structural schematic diagram of a pipeline fixing unit;

[0030] Figure 5 This is a cross-sectional structural diagram of the pipeline fixing unit;

[0031] Figure 6 for Figure 5 Enlarged view of the structure at point A;

[0032] Figure 7 This is a schematic diagram of the control component and the air extraction component.

[0033] Figure 8 This is a cross-sectional view of the sealing cylinder.

[0034] Figure 9 This is a schematic diagram of the pull component.

[0035] In the diagram: 1. Mounting bracket; 101. Positioning groove; 11. Guide rod; 21. Slider; 211. First locking tooth; 22. Bundle tube cover; 23. Airbag; 24. Connecting tube; 31. Positioning plate; 311. Clearance groove; 32. Second locking tooth; 33. Groove; 34. Fixing rod; 35. First spring; 41. Protrusion; 42. Moving plate; 43. Connecting rod; 44. Sliding rod; 45. Sliding sleeve; 51. Sealing cylinder; 52. Air pipe; 53. Sliding plug; 54. Crossbar; 55. Pull rod; 551. Fixing block; 552. Rod body; 61. Push block; 62. Mounting groove; 63. Threaded opening; 64. Clamping block; 65. Adjusting screw; 71. Fixing cylinder; 72. Vertical rod; 73. Connecting sleeve; 74. Limit cap; 75. Rotating frame; 76. Movable plate; 77. Locking groove; 78. Positioning block. Detailed Implementation

[0036] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0037] Reference Figure 1-9 The electromechanical installation pipeline quick installation anti-loosening device includes two pipeline fixing units, which are arranged vertically opposite each other. Each pipeline fixing unit includes a mounting frame 1, which has two positioning slots 101 and two guide rods 11 fixed on it.

[0038] Several slidable fixing components are provided on the two guide rods 11. The fixing components include a bundle tube cover 22. The two bundle tube covers 22 facing each other form a tubular structure. An airbag 23 is fixed on the bundle tube cover 22. The two adjacent airbags 23 are connected by a connecting tube 24. The fixing components also include a slider 21. The slider 21 is slidably sleeved on the two guide rods 11. The two guide rods 11 provide guidance for the slider 21. Several first locking teeth 211 are fixed on the bottom surface of the slider 21. The bundle tube cover 22 is fixed on the top surface of the slider 21. It should be noted that the connecting tube 24 is a telescopic tube, such as a corrugated tube, so that the movement of the slider 21 is not constrained by the connecting tube 24.

[0039] The mounting bracket 1 is provided with a positioning component for fixing the position of several fixing components. The positioning component includes a positioning plate 31 and two grooves 33. Several second locking teeth 32 are fixed on the top surface of the positioning plate 31, and two fixing rods 34 are fixed on the bottom surface of the positioning plate 31. Both grooves 33 are opened on the mounting bracket 1, and the two fixing rods 34 are respectively inserted into the two grooves 33. The positioning plate 31 and the mounting bracket 1 are connected by two first springs 35.

[0040] The mounting frame 1 is equipped with a control component for controlling the positioning component. The control component includes a protrusion 41 and a movable plate 42. The protrusion 41 is fixed to the bottom surface of the positioning plate 31. The movable plate 42 is slidably mounted on the mounting frame 1. The movable plate 42 has an inclined surface and is positioned directly opposite the protrusion 41. The movable plate 42 is connected to the mounting frame 1 through a guide structure. The guide structure includes two sliding rods 44 and two sliding sleeves 45. The two sliding rods 44 are fixed to the side of the mounting frame 1. The two sliding sleeves 45 are slidably mounted on the two sliding rods 44 respectively. The movable plate 42 and the two sliding sleeves 45 are connected by two connecting rods 43. The bottom surface of the positioning plate 31 has an clearance groove 311 that is adapted to the movable plate 42.

[0041] The mounting frame 1 is equipped with an air extraction assembly for extracting gas from several airbags 23. The air extraction assembly includes a sealing cylinder 51, which is fixed to the side of the mounting frame 1. The sealing cylinder 51 is connected to one of the airbags 23 through an air pipe 52. A sliding plug 53 is slidably connected inside the sealing cylinder 51. A crossbar 54 is fixed to the side of the sliding plug 53. The end of the crossbar 54 away from the sliding plug 53 extends to the outside of the sealing cylinder 51 and is fixed with a pull rod 55. A fixing block 551 is fixed on the pull rod 55. The fixing block 551 is connected to one of the sliding sleeves 45 through the rod body 552.

[0042] The mounting bracket 1 is equipped with a pulling component for driving the air extraction component and the control component. The pulling component includes a push block 61, which is fixed to the end of the pull rod 55 away from the crossbar 54. The push block 61 has a mounting groove 62 and a threaded opening 63, and the mounting groove 62 and the threaded opening 63 are connected. A movable clamping block 64 is provided inside the mounting groove 62. In the initial state, the clamping block 64 is inserted into one of the positioning grooves 101. At this time, the sliding plug 53 is located at one end of the sealing cylinder 51. In this case, several airbags 23 are in an inflated state. When the clamping block 64 is inserted into another positioning groove 101, the sliding plug 53 is located at the other end of the sealing cylinder 51. At this time, the gas in several airbags 23 is drawn into the interior of the sealing cylinder 51. An adjusting screw 65 is threaded into the threaded opening 63. One end of the adjusting screw 65 is rotatably connected to the clamping block 64. The clamping block 64 is positioned facing the mounting bracket 1. The other end of the adjusting screw 65 extends to the outside of the threaded opening 63.

[0043] When using the pipeline installation device proposed in this invention, the operator first adjusts the position of the upper mounting bracket 1 so that the upper and lower mounting brackets 1 are staggered, forming a configuration as shown in the figure. Figure 3 As shown in the diagram, the positions of several bundled tube covers 22 are then adjusted according to the location of the pipeline, so that the bundled tube covers 22 can fix pipelines with different spacing. When adjusting the position of the bundled tube covers 22, the operator first rotates the adjusting screw 65 to move the adjusting screw 65. When the adjusting screw 65 moves, it can drive the clamping block 64 to move, so that the clamping block 64 is disengaged from the corresponding positioning groove 101. Without the restraint of the clamping block 64, the push block 61 can move freely. When the push block 61 moves, it can drive the crossbar 54 to move through the pull rod 55. When the crossbar 54 moves, it can drive the sliding plug 53 connected to it to move. When the sliding plug 53 moves in the sealing cylinder 51, the sliding plug 53 can extract the gas inside several airbags 23 located on the same mounting bracket 1 through the air pipe 52, so that the airbags 23 can contract, so that the operator can place the pipeline in the bundled tube cover 22.

[0044] Simultaneously, when the pull rod 55 moves, it can also drive the rod body 552 to move via the fixed block 551. When the rod body 552 moves, it drives the connected sliding sleeve 45 to move, thereby causing the moving plate 42 to move. Figure 5 and Figure 6 As shown, in the initial state, the protrusion 41 is directly opposite the highest point of the moving plate 42. At this time, under the action of the moving plate 42, the second teeth 32 on the positioning plate 31 and the first teeth 211 on the slider 21 are engaged. At this time, the positioning plate 31 constrains the slider 21, and the slider 21 cannot move. When the moving plate 42 moves, the lowest point of the moving plate 42 gradually approaches the position directly opposite the protrusion 41. During this process, the positioning plate 31 will move downward under the action of the two first springs 35, and finally the second teeth 32 on the positioning plate 31 and the first teeth 211 on the slider 21 will separate from each other. Without the constraint of the positioning plate 31 and the second teeth 32 on it, the slider 21 can move freely. At this time, the operator can adjust the position of the tube cover 22 by pulling the slider 21, so that the tube cover 22 can constrain and fix the pipelines with different spacing.

[0045] It is worth noting that when the operator moves the clamping block 64 to a position directly opposite the other positioning groove 101, the operator turns the adjusting screw 65 again, causing the adjusting screw 65 to drive the clamping block 64 to reset until the clamping block 64 is engaged in the opposite positioning groove 101. In this case, the clamping block 64 and the positioning groove 101 cooperate with each other to fix the push block 61. When the position of the push block 61 is fixed, the positions of the pull rod 55, the crossbar 54 and the slide plug 53 are also fixed, and the position of the positioning plate 31 is also fixed, so that the operator can adjust the position of the bundle tube cover 22.

[0046] The two mounting brackets 1 are connected by a connecting assembly, which consists of a rotating structure and a clamping structure. The rotating structure includes a fixed cylinder 71 and a connecting sleeve 73. The fixed cylinder 71 is fixed on the lower mounting bracket 1, and a vertical rod 72 is fixed on the fixed cylinder 71. The connecting sleeve 73 is fixed on the upper mounting bracket 1, and the connecting sleeve 73 is movably sleeved on the vertical rod 72. A limit cap 74 is fixed to the end of the vertical rod 72 away from the fixed cylinder 71. The clamping structure includes a rotating frame 75 and a positioning block 78. The rotating frame 75 is rotatably mounted on the upper mounting bracket 1. A movable plate 76 is slidably arranged on the rotating frame 75. A slot 77 is opened at the end of the movable plate 76 away from the rotating frame 75. The shape of the slot 77 is adapted to the shape of the positioning block 78. The rotating frame 75 and the movable plate 76 are connected by a tension spring.

[0047] After adjusting the position of each tube cover 22, the operator places the tubing on the tube cover 22, ensuring the tubing rests on the airbag 23, and rotates the upper mounting bracket 1 to align the upper and lower mounting brackets 1. Figure 1 As shown, when the two mounting brackets 1 are aligned vertically, the operator can adjust the position of the movable plate 76 by pulling and rotating until the slot 77 on the movable plate 76 is engaged with the positioning block 78 on the lower mounting bracket 1. The movable plate 76 and the rotating bracket 75 are connected by a tension spring. Under the action of the tension spring, the movable plate 76 always has an upward tendency, which makes the movable plate 76 and the positioning block 78 work together to fix the two mounting brackets 1, thereby ensuring the device's fixing effect on the pipeline. It should be noted that when the upper mounting bracket 1 rotates, it can drive the connecting sleeve 73 to rotate, so that the connecting sleeve 73 rotates on the vertical rod 72. In addition, the connecting sleeve 73 can also move up and down along the vertical rod 72. The limit cap 74 on the vertical rod 72 can prevent the connecting sleeve 73 from falling off the vertical rod 72.

[0048] After the docking between the two mounting brackets 1 is completed, the operator controls the push block 61 to reset again. When the push block 61 resets, the pull rod 55, the crossbar 54 and the slide plug 53 also reset. When the pull rod 55 resets, it can drive the corresponding sliding sleeve 45 to reset, so that the moving plate 42 resets. During the reset process, the inclined surface of the moving plate 42 will squeeze the protrusion 41, so that the protrusion 41 drives the positioning plate 31 to move upward. When the positioning plate 31 moves upward, the positioning plate 31 and its several second locking teeth 32 provide constraint on the slider 21 again, thereby fixing the bundle tube cover 22, thus ensuring the fixing effect of the device on the pipeline and preventing the pipeline from becoming loose or shaking. When the slide plug 53 resets, the slide plug 53 can push the gas in the sealing cylinder 51 back into several air bags 23, so that the air bags 23 inflate and expand. The expanded air bags 23 can wrap around the pipeline, thereby fixing pipelines of different diameters.

[0049] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A quick-installation anti-loosening device for electromechanical installation pipelines, characterized in that, It includes two pipeline fixing units, which are arranged vertically opposite each other. Each pipeline fixing unit includes a mounting frame (1). The mounting frame (1) has two positioning slots (101). The mounting frame (1) has two guide rods (11) fixed on it. The two guide rods (11) are provided with several slidable fixing components. The mounting frame (1) is provided with positioning components for fixing the positions of several fixing components. The mounting frame (1) is provided with control components for controlling the positioning components. The fixing assembly includes a tube cover (22), on which an airbag (23) is fixed. Two adjacent airbags (23) are connected by a connecting tube (24). The mounting frame (1) is provided with an air extraction assembly for extracting gas from several airbags (23). The air extraction assembly includes a pull rod (55) and a crossbar (54). The mounting bracket (1) is provided with a pulling component for driving the air extraction component and the control component to operate. The pulling component includes a push block (61). The push block (61) is fixed to the end of the pull rod (55) away from the crossbar (54). The push block (61) is provided with a mounting groove (62) and a threaded opening (63), and the mounting groove (62) and the threaded opening (63) are connected. A movable clamping block (64) is provided inside the mounting groove (62). An adjusting screw (65) is threaded into the threaded opening (63). One end of the adjusting screw (65) is rotatably connected to the clamping block (64). The two mounting brackets (1) are connected by a connecting assembly; The fixing assembly also includes a slider (21), which is slidably sleeved on two guide rods (11). The bottom surface of the slider (21) is fixed with a number of first locking teeth (211), and the bundle tube cover (22) is fixed on the top surface of the slider (21). The positioning assembly includes a positioning plate (31) and two grooves (33). The top surface of the positioning plate (31) is fixed with several second teeth (32), and the bottom surface of the positioning plate (31) is fixed with two fixing rods (34). The two grooves (33) are both opened on the mounting frame (1), and the two fixing rods (34) are respectively inserted into the two grooves (33). The positioning plate (31) and the mounting frame (1) are connected by two first springs (35). The control component includes a protrusion (41) and a movable plate (42). The protrusion (41) is fixed on the bottom surface of the positioning plate (31). The movable plate (42) is slidably mounted on the mounting frame (1). The movable plate (42) has an inclined surface and is positioned directly opposite the protrusion (41). The movable plate (42) is connected to the mounting frame (1) through a guide structure. The guide structure includes two slide rods (44) and two sliding sleeves (45). The two slide rods (44) are fixed on the side of the mounting bracket (1), and the two sliding sleeves (45) are slidably sleeved on the two slide rods (44). The moving plate (42) is connected to the two sliding sleeves (45) through two connecting rods (43). The air extraction assembly includes a sealing cylinder (51), which is fixed to the side of the mounting bracket (1). The sealing cylinder (51) is connected to one of the airbags (23) via an air pipe (52). A sliding plug (53) is slidably connected inside the sealing cylinder (51). A crossbar (54) is fixed to the side of the sliding plug (53). The end of the crossbar (54) away from the sliding plug (53) extends to the outside of the sealing cylinder (51). A pull rod (55) is fixed to the end of the crossbar (54) away from the sliding plug (53). A fixing block (551) is fixed on the pull rod (55). The fixing block (551) is connected to one of the sliding sleeves (45) via a rod body (552).

2. The quick-installation anti-loosening device for electromechanical installation pipelines according to claim 1, characterized in that, The clamping block (64) is positioned opposite the mounting bracket (1), and the other end of the adjusting screw (65) extends to the outside of the threaded opening (63).

3. The quick-installation anti-loosening device for electromechanical installation pipelines according to claim 2, characterized in that, The two tube covers (22) facing each other vertically together form a tubular structure.

4. The quick-installation anti-loosening device for electromechanical installation pipelines according to claim 3, characterized in that, The bottom surface of the positioning plate (31) is provided with a clearance groove (311) that is compatible with the moving plate (42).

5. The quick-installation anti-loosening device for electromechanical installation pipelines according to claim 4, characterized in that, The connecting assembly consists of a rotating structure and a clamping structure. The rotating structure includes a fixed cylinder (71) and a connecting sleeve (73). The fixed cylinder (71) is fixed on the mounting bracket (1) at the lower end. A vertical rod (72) is fixed on the fixed cylinder (71). The connecting sleeve (73) is fixed on the mounting bracket (1) at the upper end, and the connecting sleeve (73) is movably sleeved on the vertical rod (72). A limit cap (74) is fixed at the end of the vertical rod (72) away from the fixed cylinder (71).

6. The quick-installation anti-loosening device for electromechanical installation pipelines according to claim 5, characterized in that, The clamping structure includes a rotating frame (75) and a positioning block (78). The rotating frame (75) is rotatably mounted on the upper mounting bracket (1). A movable plate (76) is slidably arranged on the rotating frame (75). A slot (77) is opened at one end of the movable plate (76) away from the rotating frame (75). The shape of the slot (77) is adapted to the shape of the positioning block (78). The rotating frame (75) and the movable plate (76) are connected by a tension spring.

Images