Telescopic long cantilever structure suitable for working in long and narrow space

Abstract

The telescopic long cantilever structure suitable for working in the long and narrow space comprises a fixed arm, a movable arm is coaxially arranged in the fixed arm in a sliding mode, and a supporting and guiding assembly is arranged between the interior of the fixed arm and the movable arm; a driving assembly for driving the moving arm to axially move is arranged at the end part of one end, positioned in the fixed arm, of the moving arm; the supporting and guiding assembly comprises a guiding part and a sliding supporting part, the guiding part is arranged on the inner wall of the fixed arm, the sliding supporting part is axially and movably arranged on the side wall of the movable arm, the sliding supporting part and the guiding part are axially connected in a sliding fit mode, and the fit width between the sliding supporting part and the guiding part is adjustable. The axial relative position between the sliding supporting part and the movable arm is adjustable; the two-stage telescopic structure is adopted for cantilever stretching, control is easy, operation is stable, the fulcrum position can be adjusted in real time according to the stretching stroke, deformation of the movable arm is effectively avoided, and the positioning precision of the execution tail end work robot is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of cantilever telescopic structure technology, specifically relating to a telescopic long cantilever structure suitable for working in narrow spaces. Background Technology

[0002] When performing long-stroke operations such as spraying, paint removal, and sanding in narrow spaces, the working range of the relevant robot itself cannot meet the requirements of long-stroke operations. In the existing technology, a cantilever telescopic mechanism is usually used to drive the working robot to extend and retract its cantilever, thereby driving the working robot to extend into the narrow space to perform the operation.

[0003] However, existing cantilever telescopic structures have the following drawbacks: 1. For long-stroke telescopic operations, such as telescopic operations with a stroke of more than 5m, a multi-stage telescopic boom structure is required. However, the telescopic speed is low, and the control load of the multi-stage telescopic boom has low end-positioning accuracy, which makes it difficult to meet the needs of precise positioning operations in narrow spaces. 2. The fixed fulcrum position of the mobile arm makes it difficult to adapt to different extension strokes and adjust the position of the fulcrum. Especially when the extension stroke is greater than 5m, the fixed fulcrum position is difficult to effectively support the mobile arm, causing the mobile arm to bend and deform under its own weight and end load, which in turn affects the positioning accuracy of the end-effector robot.

[0004] Therefore, in view of the above-mentioned shortcomings of existing long-stroke cantilever telescopic structures, this invention discloses a telescopic long cantilever structure suitable for working in narrow spaces. Summary of the Invention

[0005] This invention discloses a retractable long cantilever structure suitable for working in narrow spaces. It adopts a two-stage telescopic structure for cantilever extension and retraction, which is simple to control and runs smoothly. Furthermore, it can adjust the fulcrum position in real time according to the extension stroke, effectively avoiding deformation of the moving arm and ensuring the positioning accuracy of the end-effector robot.

[0006] This invention is achieved through the following technical solution: A retractable long cantilever structure suitable for operation in narrow spaces includes a fixed arm, a movable arm slidably disposed coaxially inside the fixed arm, a support and guide assembly disposed between the fixed arm and the movable arm, and a drive assembly for axially moving the movable arm at one end inside the fixed arm; the support and guide assembly includes a guide part and a sliding support part, the guide part being disposed on the inner wall of the fixed arm, the sliding support part being axially movably disposed on the side wall of the movable arm, the sliding support part and the guide part being axially slidably connected, the fit width between the sliding support part and the guide part being adjustable, and the axial relative position between the sliding support part and the movable arm being adjustable.

[0007] When extension or retraction is required, the drive assembly propels the movable arm to extend or retract axially relative to the fixed arm. During this axial extension or retraction, the sliding engagement between the guide section and the sliding support section precisely guides the axial extension or retraction of the movable arm. Compared to traditional telescopic cantilever structures where the movable arm's fulcrum is not adjustable, the sliding support section acts as the fulcrum for supporting the movable arm. Furthermore, the sliding support section itself can be adjusted axially relative to the movable arm, thereby adjusting the fulcrum position of the movable arm. This allows for adjustable fulcrum support to accommodate different extension lengths of the movable arm, while always ensuring that the fulcrum position of the movable arm remains within the fixed arm.

[0008] To better realize the present invention, the guide portion further includes a V-shaped guide rail, a planar guide rail, and a spacing adjustment device; the sliding support portion includes a V-groove guide wheel and a planar guide wheel. Two sets of V-shaped guide rails are parallelly arranged on the first inner wall of the fixed arm, and the V-shaped guide rails are slidably connected to the first inner wall in a vertical direction perpendicular to the axial direction. Two sets of planar guide rails are parallelly arranged on the second inner wall of the fixed arm, and the planar guide rails are slidably connected to the second inner wall in a vertical direction perpendicular to the axial direction. A spacing adjustment device is provided between the two sets of V-shaped guide rails and between the two sets of planar guide rails. Two sets of V-groove guide wheels are axially movable on the first outer wall of the moving arm, and the two sets of V-groove guide wheels are slidably connected to the two sets of V-shaped guide rails respectively. Two sets of planar guide wheels are axially movable on the second outer wall of the moving arm, and the two sets of planar guide wheels are slidably connected to the two sets of planar guide rails respectively.

[0009] To better realize the present invention, the sliding support further includes an adapter seat and an axial drive unit. The adapter seat is slidably sleeved on the outside of the moving arm along the axial direction. One end of the fixed arm is provided with an axial drive unit that drives the adapter seat to slide axially and to stop and position axially. A V-groove guide wheel or a flat guide wheel is provided on the side of the adapter seat away from the moving arm.

[0010] To better realize the present invention, an elastic tensioning device is further provided between the two sets of V-groove guide wheels and between the two sets of planar guide wheels.

[0011] To better realize the present invention, a guide rail support plate is further provided on one side of the V-shaped guide rail or the flat guide rail, and a support groove is provided on the guide rail support plate. A positioning pin is provided on one side of the V-shaped guide rail or the flat guide rail, extending into the support groove and sliding vertically along the support groove. An adjusting bolt is threadedly provided inside the support groove in the vertical direction, and one end of the adjusting bolt abuts against the side of the positioning pin.

[0012] To better realize the present invention, the spacing adjustment device further includes a double-rotor screw, and the side of the guide rail support plate away from the V-shaped guide rail or the flat guide rail is threadedly connected to the double-rotor screw, and the double-rotor screw is rotatably mounted on the fixed arm.

[0013] To better realize the present invention, the first inner wall and the second inner wall of the fixed arm are provided with vertical sliding grooves. One side of the guide rail support plate is slidably connected to the vertical sliding groove. The inner wall of the vertical sliding groove is provided with a plurality of elastic locking members of different heights. The side wall of the guide rail support plate is provided with locking holes corresponding to the elastic locking members.

[0014] To better realize the present invention, the drive assembly further includes a drive gear, a rack, a geared motor assembly, and a geared mounting bracket. The geared motor assembly is fixedly mounted on the outside of the moving arm via the geared mounting bracket. The rack is mounted on one side of the V-shaped guide rail and / or the planar guide rail. A drive gear that meshes with the rack is sleeved on the output shaft of the geared motor assembly.

[0015] To better realize the present invention, the movable arm is further provided with process holes and process grooves, and a process hole end cap is installed at the process hole.

[0016] Compared with the prior art, the present invention has the following advantages and beneficial effects: This invention employs a two-stage telescopic structure formed by the sliding cooperation of a mobile arm and a fixed arm, driving the end-effector robot to perform accurate positioning and movement within a narrow space. During the extension and retraction of the mobile arm, it can accurately guide the arm and ensure its smooth movement. Simultaneously, the position of the fulcrum of the mobile arm can be adjusted according to the extension stroke, achieving stable support for the arm. Furthermore, adjusting the fulcrum position effectively prevents deformation of the mobile arm under its own weight and end-effector load during long extension strokes, thus effectively ensuring the positioning accuracy of the end-effector robot and enabling high-precision positioning operations within narrow spaces. Moreover, the use of a two-stage telescopic structure for long extension strokes, replacing a multi-stage telescopic structure, simplifies the control of the long cantilever structure and results in a faster and more accurate motion response. Attached Figure Description

[0017] Figure 1 A three-dimensional structural diagram of a retractable long cantilever structure; Figure 2 This is a cross-sectional view of a retractable long cantilever structure. Figure 3 A schematic diagram showing the fit between the V-groove guide wheel and the V-shaped guide rail; Figure 4 This is a schematic diagram of the installation of the V-shaped guide rail; Figure 5This is a schematic diagram showing the movable arm extending from the fixed arm.

[0018] Wherein: 100-moving arm; 200-fixed arm; 300-support and guide assembly; 400-drive assembly; 101-process hole; 102-process groove; 103-process hole end cap; 301-V-groove guide wheel; 302-flat guide wheel; 303-V-shaped guide rail; 304-flat guide rail; 305-guide rail support plate; 401-drive gear; 402-rack; 501-positioning pin; 502-adjusting bolt. Detailed Implementation

[0019] Example 1: This embodiment provides a retractable long cantilever structure suitable for operation in narrow spaces, such as... Figure 1 , Figure 2 , Figure 3 , Figure 5 As shown, the device includes a fixed arm 200, a movable arm 100 slidably disposed coaxially inside the fixed arm 200, and a support and guide assembly 300 disposed between the fixed arm 200 and the movable arm 100. A drive assembly 400 for axially moving the movable arm 100 is disposed at one end of the movable arm 100 located inside the fixed arm 200. The support and guide assembly 300 includes a guide portion and a sliding support portion. The guide portion is disposed on the inner wall of the fixed arm 200, and the sliding support portion is axially movably disposed on the side wall of the movable arm 100. The sliding support portion and the guide portion are axially slidably connected, the fit width between the sliding support portion and the guide portion is adjustable, and the axial relative position between the sliding support portion and the movable arm 100 is adjustable.

[0020] The fixed arm 200 is a hollow frame structure, and the movable arm 100 is also a hollow frame structure. The movable arm 100 is axially slidably mounted inside the fixed arm 200. A support and guide assembly 300 is provided inside the fixed arm 200 between the two opposite side walls and the movable arm 100. The support and guide assembly 300 guides the extension and retraction of the movable arm 100 and provides a stable fulcrum. The drive assembly 400 drives the movable arm 100 to move axially relative to the fixed arm 200, thus realizing the extension and retraction of the movable arm 100.

[0021] The support and guide assembly 300 includes a guide portion and a sliding support portion. The guide portion is fixedly installed on the inner wall of the fixed arm 200, while the sliding support portion is axially slidably disposed on the outer wall of the movable arm 100. The guide portion and the sliding support portion are axially slidably connected. The guide portion guides the axial sliding of the sliding support portion and the movable arm 100 and restricts the axial position of the movable arm 100. At the same time, the sliding support portion itself can move axially relative to the movable arm 100, thereby adjusting the fulcrum position of the sliding support portion relative to the movable arm 100.

[0022] In practical use, to accommodate the telescopic length of the movable arm 100, one or more sets of sliding support parts are provided on the outer wall of the movable arm 100. The axial position of each set of sliding support parts relative to the movable arm 100 is adjustable, thereby flexibly adjusting the number and position of the fulcrums of the movable arm 100. This allows for stable guidance and support of the movable arm 100 to accommodate different extension lengths and end loads, ensuring that the coaxiality error between the axis of the movable arm 100 and the axis of the fixed arm 200 is within the allowable error range. Simultaneously, by adjusting the position of the fulcrums, it is ensured that the fulcrums are always located inside the fixed arm 200, providing rigid support for the movable arm 100 and preventing deformation due to its own weight and end load when the cantilever length of the movable arm 100 is large.

[0023] Example 2: This embodiment discloses a retractable long cantilever structure suitable for operation in narrow spaces, which is an improvement on Embodiment 1, such as... Figure 2 , Figure 3 As shown, the guide portion includes a V-shaped guide rail 303, a flat guide rail 304, and a spacing adjustment device. The sliding support portion includes a V-groove guide wheel 301 and a flat guide wheel 302. The two sets of V-shaped guide rails 303 are arranged parallel to each other on the first inner wall of the fixed arm 200, and the V-shaped guide rails 303 are slidably connected to the first inner wall in a vertical direction perpendicular to the axial direction. The two sets of flat guide rails 304 are arranged parallel to each other on the second inner wall of the fixed arm 200, and the flat guide rails 304 are slidably connected to the second inner wall in a vertical direction perpendicular to the axial direction. The vertical sliding connection is provided; a spacing adjustment device is provided between the two sets of V-shaped guide rails 303 and between the two sets of planar guide rails 304; the two sets of V-shaped groove guide wheels 301 are axially movable and disposed on the first outer wall of the moving arm 100, and the two sets of V-shaped groove guide wheels 301 are slidably connected to the two sets of V-shaped guide rails 303 respectively; the two sets of planar guide wheels 302 are axially movable and disposed on the second outer wall of the moving arm 100, and the two sets of planar guide wheels 302 are slidably connected to the two sets of planar guide rails 304 respectively.

[0024] The upper and lower sides of the first outer wall of the movable arm 100 are axially rotatably provided with a plurality of V-groove guide wheels 301. Simultaneously, two sets of V-shaped guide rails 303 are provided on the upper and lower sides of the first inner wall of the fixed arm 200, corresponding to the rim positions of the V-groove guide wheels 301. Through the sliding engagement between the V-shaped protrusions of the V-shaped guide rails 303 and the V-shaped grooves on the rims of the V-groove guide wheels 301, the extension and retraction of the movable arm 100 is guided, and the axial position of the movable arm 100 is also positioned. The upper and lower sides of the second outer wall of the movable arm 100 are axially rotatably provided with a plurality of planar guide wheels 302. The first and second outer walls are two opposing side walls. Simultaneously, two sets of planar guide rails 304 are provided on the upper and lower sides of the second inner wall of the fixed arm 200, corresponding to the rim positions of the planar guide wheels 302. The first and second inner walls are two opposing side walls. The rolling engagement between the planar guide rail 304 and the rim of the planar guide wheel 302 achieves the telescopic guidance of the movable arm 100, while ensuring the smoothness of the telescopic movement of the movable arm 100.

[0025] The spacing between the two sets of V-shaped guide rails 303, the spacing between the two sets of flat guide rails 304, the spacing between the V-shaped groove guide wheels 301 on the upper and lower sides, and the spacing between the flat guide wheels 302 on the upper and lower sides are all adjustable, thus enabling them to adapt to different narrow spaces for installation.

[0026] Furthermore, the sliding support also includes an adapter seat and an axial drive unit. The adapter seat is axially slidably sleeved on the outside of the movable arm 100. One end of the fixed arm 200 is provided with an axial drive unit that drives the adapter seat to slide axially and to stop and position it axially. A V-groove guide wheel 301 or a flat guide wheel 302 is provided on the side of the adapter seat away from the movable arm 100. The V-groove guide wheel 301 and the flat guide wheel 302 are slidably mounted on the adapter seat through wheel seats. The wheel seats can slide vertically relative to the adapter seat to adjust the distance between the guide wheels. The axial drive unit includes a drive reduction motor set and a drive screw. One end of the drive screw is connected to the output shaft of the drive reduction motor set. The drive reduction motor set is mounted on one end of the fixed arm 200. The drive screw is connected to a threaded hole on the adapter seat. The drive reduction motor set drives the drive screw to rotate, thereby driving the adapter seat to move axially outside the movable arm 100 to adjust the position of the fulcrum of the movable arm 100.

[0027] Furthermore, an elastic tensioning device is provided between the two sets of V-groove guide wheels 301 and between the two sets of flat guide wheels 302. The elastic tensioning device is used to press the V-groove guide wheels 301 toward the V-shaped guide rail 303 and the flat guide wheels 302 toward the flat guide rail 304, thereby ensuring a tight fit between the V-groove guide wheels 301 and the V-shaped guide rail 303, and between the flat guide wheels 302 and the flat guide rail 304, improving the stability of the extension and retraction of the moving arm 100.

[0028] The rest of this embodiment is the same as that of Embodiment 1, so it will not be described again.

[0029] Example 3: This embodiment discloses a retractable long cantilever structure suitable for operation in narrow spaces, which is an optimization based on embodiment 1 or 2, such as... Figure 2 , Figure 4 As shown, a guide rail support plate 305 is provided on one side of the V-shaped guide rail 303 or the flat guide rail 304. A support groove is provided on the guide rail support plate 305. A positioning pin 501 is provided on one side of the V-shaped guide rail 303 or the flat guide rail 304, extending into the support groove and sliding vertically along it. An adjusting bolt 502 is threaded into the interior of the support groove in the vertical direction. One end of the adjusting bolt 502 abuts against the side of the positioning pin 501. By rotating the adjusting bolt 502, the depth of the adjusting bolt 502 into the support groove is controlled. Furthermore, by adjusting the abutment depth of the bolt 502 against the positioning pin 501, the V-shaped guide rail 303 or the flat guide rail 304 is leveled and locked, ensuring that the V-shaped guide rail 303 or the flat guide rail 304 is set in the horizontal direction.

[0030] The rest of this embodiment is the same as that of embodiment 1 or 2, so it will not be described again.

[0031] Example 4: This embodiment discloses a retractable long cantilever structure suitable for operation in narrow spaces, which is optimized based on any one of embodiments 1-3, such as... Figure 2 As shown, the spacing adjustment device includes a double-rotor screw. The side of the guide rail support plate 305 away from the V-shaped guide rail 303 or the flat guide rail 304 is threadedly connected to the double-rotor screw. The double-rotor screw is rotatably mounted on the fixed arm 200.

[0032] After leveling the V-shaped guide rails 303 or the flat guide rails 304, to adjust the distance between the two sets of V-shaped guide rails 303 or the two sets of flat guide rails 304, the double-rotor screw can be rotated. The upper and lower ends of the double-rotor screw have threads with opposite directions of rotation, which engage with threaded holes on one side of the guide rail support plate 305. This causes the upper and lower guide rail support plates 305 to move closer or further apart, thereby moving the two sets of V-shaped guide rails 303 closer or further apart. The adjustment of the distance between the two sets of flat guide rails 304 is similar and will not be described further here. After the distance adjustment is completed, the self-locking property of the threads prevents the guide rails from shifting.

[0033] Vertical sliding grooves are provided on both the first and second inner walls of the fixed arm 200. One side of the guide rail support plate 305 is slidably connected to the vertical sliding groove. Several elastic locking elements of different heights are provided on the inner wall of the vertical sliding groove. Locking holes are provided on the side wall of the guide rail support plate 305 corresponding to the elastic locking elements. When the guide rail support plate 305 is raised or lowered to a preset height, the elastic locking elements align with the locking holes. Under their own elasticity, the elastic locking elements extend into the locking holes, thereby locking the guide rail support plate 305 and further preventing the guide rail support plate 305 from moving.

[0034] The rest of this embodiment is the same as any one of embodiments 1-3, so it will not be described again.

[0035] Example 5: This embodiment discloses a retractable long cantilever structure suitable for operation in narrow spaces, which is optimized based on any one of embodiments 1-4, such as... Figure 2 As shown, the drive assembly 400 includes a drive gear 401, a rack 402, a geared motor assembly, and a geared mounting bracket. The geared motor assembly is fixedly mounted on the outside of the moving arm 100 via the geared mounting bracket. The rack 402 is mounted on one side of the V-shaped guide rail 303 and / or the flat guide rail 304. The drive gear 401, which meshes with the rack 402, is sleeved on the output shaft of the geared motor assembly.

[0036] The drive gear 401 is rotated by the geared motor, and the moving arm 100 is moved axially along the direction of the rack 402 through the meshing structure between the drive gear 401 and the rack 402. Furthermore, the self-locking meshing between the drive gear 401 and the rack 402 can prevent the moving arm 100 from continuing to move axially after it stops extending or retracting.

[0037] Furthermore, the mobile arm 100 is provided with a process hole 101, and a process hole end cap 103 is installed at the process hole 101. The side wall of the mobile arm 100 is provided with the process hole 101 and the process groove 102. The process hole 101 helps to reduce the weight of the mobile arm 100 and facilitates maintenance and installation. The process groove 102 reduces the weight of the mobile arm 100 while maintaining sufficient rigidity to support the cantilevered end of the robot. The process hole 101 is sealed by the process hole end cap 103 to prevent external dust and other impurities from entering the mobile arm 100.

[0038] The rest of this embodiment is the same as any one of embodiments 1-4, so it will not be described again.

[0039] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A retractable long cantilever structure suitable for operation in narrow spaces, comprising a fixed arm (200), wherein a movable arm (100) is coaxially slidably disposed inside the fixed arm (200), characterized in that, A support and guide assembly (300) is provided between the interior of the fixed arm (200) and the movable arm (100). The end of the movable arm (100) located inside the fixed arm (200) is provided with a drive assembly (400) for axial movement of the movable arm (100). The support and guide assembly (300) includes a guide part and a sliding support part. The guide part is provided on the inner wall of the fixed arm (200). The sliding support part is axially movably provided on the side wall of the movable arm (100). The sliding support part and the guide part are axially slidably connected. The fit width between the sliding support part and the guide part is adjustable. The axial relative position between the sliding support part and the movable arm (100) is adjustable.

2. The retractable long cantilever structure suitable for operation in narrow spaces according to claim 1, characterized in that, The guide section includes a V-shaped guide rail (303), a flat guide rail (304), and a spacing adjustment device. The sliding support section includes a V-groove guide wheel (301) and a flat guide wheel (302). The two sets of V-shaped guide rails (303) are arranged parallel to each other on the first inner wall of the fixed arm (200), and the V-shaped guide rails (303) are slidably connected to the first inner wall in a vertical direction perpendicular to the axial direction. The two sets of flat guide rails (304) are arranged parallel to each other on the second inner wall of the fixed arm (200), and the flat guide rails (304) are slidably connected to the second inner wall in a vertical direction perpendicular to the axial direction. The vertical sliding connection is provided; a spacing adjustment device is provided between the two sets of V-shaped guide rails (303) and between the two sets of planar guide rails (304); the two sets of V-shaped groove guide wheels (301) are axially movable and set on the first outer wall of the moving arm (100), and the two sets of V-shaped groove guide wheels (301) are slidably connected to the two sets of V-shaped guide rails (303); the two sets of planar guide wheels (302) are axially movable and set on the second outer wall of the moving arm (100), and the two sets of planar guide wheels (302) are slidably connected to the two sets of planar guide rails (304).

3. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 2, characterized in that, The sliding support also includes an adapter seat and an axial drive unit. The adapter seat is slidably sleeved on the outside of the movable arm (100) along the axial direction. One end of the fixed arm (200) is provided with an axial drive unit that drives the adapter seat to slide axially and stop axially. A V-groove guide wheel (301) or a flat guide wheel (302) is provided on the side of the adapter seat away from the movable arm (100).

4. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 3, characterized in that, An elastic tensioning device is provided between the two sets of V-groove guide wheels (301) and between the two sets of planar guide wheels (302).

5. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 4, characterized in that, A guide rail support plate (305) is provided on one side of the V-shaped guide rail (303) or the flat guide rail (304). A support groove is provided on the guide rail support plate (305). A positioning pin (501) is provided on one side of the V-shaped guide rail (303) or the flat guide rail (304) extending into the support groove and sliding vertically along the support groove. An adjusting bolt (502) is threaded in the vertical direction inside the support groove. One end of the adjusting bolt (502) abuts against the side of the positioning pin (501).

6. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 5, characterized in that, The spacing adjustment device includes a double-screw, and the side of the guide rail support plate (305) away from the V-shaped guide rail (303) or the flat guide rail (304) is threadedly connected to the double-screw. The double-screw is rotatably mounted on the fixed arm (200).

7. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 5, characterized in that, Vertical sliding grooves are provided on the first inner wall and the second inner wall of the fixed arm (200). One side of the guide rail support plate (305) is slidably connected to the vertical sliding groove. Several elastic locking elements of different heights are provided on the inner wall of the vertical sliding groove. Locking holes are provided on the side wall of the guide rail support plate (305) corresponding to the elastic locking elements.

8. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 4, characterized in that, The drive assembly (400) includes a drive gear (401), a rack (402), a geared motor assembly, and a geared mounting bracket. The geared motor assembly is fixedly mounted on the outside of the moving arm (100) via the geared mounting bracket. The rack (402) is mounted on one side of the V-shaped guide rail (303) and / or the flat guide rail (304). The output shaft of the geared motor assembly is fitted with a drive gear (401) that meshes with the rack (402).

9. A retractable long cantilever structure suitable for operation in narrow spaces according to claim 4, characterized in that, The movable arm (100) is provided with a process hole (101) and a process groove (102), and a process hole end cap (103) is installed at the process hole (101).

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