A central control steering linkage mechanism for a mobile C-arm X-ray machine

Abstract

This application discloses a central control steering linkage mechanism for a mobile C-arm X-ray machine, relating to an X-ray machine. It includes a lower sprocket mounting base and a base fixed to one side of the lower sprocket mounting base. Rollers that drive the entire device are rotatably mounted on both sides of the lower end of the lower sprocket mounting base. A steering mechanism for transmitting power is rotatably mounted on one side of the base. A fixed column is fixed in the middle of the base, and an upper sprocket mounting base is fixed at the top of the fixed column. A control mechanism for controlling the direction of movement of the entire device is rotatably mounted on the middle of one side of the upper sprocket mounting base. This application drives gear one by rotating a steering handle, which, under the power transmission of the transmission roller chain, drives gear two and two sprocket drive shafts to rotate, simultaneously driving two gear four to rotate, thereby controlling the rotation angle of the rollers. The cooperation of the chain, gears, bearings, and other components increases the response speed and transmission efficiency of the device.

Description

Technical Field

[0001] This application relates to X-ray machines, and more particularly to a central control steering linkage mechanism for a mobile C-arm X-ray machine. Background Technology

[0002] The mobile C-arm X-ray machine is a portable medical imaging device with a C-shaped robotic arm structure. It integrates cutting-edge X-ray fluoroscopy and digital imaging technologies. This device can be easily moved between various clinical environments such as operating rooms, emergency rooms, and catheterization labs. With its real-time dynamic imaging capabilities, it provides precise imaging support for medical procedures such as interventional surgery, orthopedic reduction, and internal fixation, enhancing surgical safety. The central control steering linkage mechanism is the core mechanical structure of the mobile C-arm X-ray machine. It is used to coordinate the multi-axis linkage of various components, allowing the device to be precisely positioned and acquire images in real time during surgery.

[0003] Traditional linkage mechanisms often employ transmission structures such as worm gear drives, rack and pinion / belt drives, which have low transmission efficiency and slow dynamic response. Under long-term high-frequency use, components are prone to jamming or even breakage, requiring frequent replacement of parts, increasing maintenance costs and downtime. Furthermore, some equipment lacks a central control handle locking device, requiring continuous force to maintain the position during operation. Even slight shaking can cause the equipment to shift, potentially leading to surgical risks. It is also difficult to quickly and accurately adjust the target angle, which can affect surgical efficiency in emergency situations. Utility Model Content

[0004] To improve the dynamic response of the equipment, as well as the issues of equipment angle adjustment and stability, this application provides a central control steering linkage mechanism for a mobile C-arm X-ray machine.

[0005] The technical solution provided in this application for a central control steering linkage mechanism for a mobile C-arm X-ray machine is as follows:

[0006] A central control steering linkage mechanism for a mobile C-arm X-ray machine includes a lower sprocket fixing seat and a base fixed to one side of the lower sprocket fixing seat. Rollers that drive the entire device are rotatably mounted on both sides of the lower end of the lower sprocket fixing seat. A steering mechanism for transmitting power is rotatably mounted on one side of the base. A fixed column is fixed in the middle of the base, and an upper sprocket fixing seat is fixed at the top of the fixed column. A control mechanism for controlling the movement direction of the entire device is rotatably mounted on the middle of one side of the upper sprocket fixing seat. Handles for pushing the entire device are fixed on both sides of the upper sprocket fixing seat adjacent to the control mechanism. The steering mechanism includes a rotating rod and two fixed rods fixed at both ends of the rotating rod. Gears two and three are fixedly mounted in the middle of the fixed rods one and two sides respectively. Gear one is movably mounted on one side of gear two. A transmission roller chain meshes with the outer side of gear two and gear one.

[0007] By adopting the above technical solution, the device realizes the movement and direction control of the device through components such as the steering mechanism and the control mechanism, providing a basis for the flexible use of the equipment and improving the convenience and efficiency of the equipment.

[0008] Preferably, each of the two rollers is fixedly provided with a mounting rod at its top end, and a gear four is fixedly sleeved in the middle of the two mounting rods. The gear three meshes with the outer sides of the two gear fours with a drive roller chain, and the upper ends of the two mounting rods are rotatably disposed on both sides of the lower end of the lower sprocket fixing seat.

[0009] By adopting the above technical solution, the roller chain is driven by the meshing of gear three and two gear fours, realizing the linkage rotation of the two rollers, making the movement of the device more coordinated and stable. The connection between the mounting rod and the lower sprocket fixing seat provides stable support for the rollers and ensures the stability of the device's movement.

[0010] Preferably, two sprocket drive shafts are fixedly installed inside the lower sprocket fixing seat near one of its rollers, and bearings are fixedly sleeved at the lower ends of the two sprocket drive shafts. The driving roller chain passes through gear three, the two bearings one and the two gears four in sequence, and the chain links of the driving roller chain mesh with the tooth grooves of gear three and the two gears four.

[0011] By adopting the above technical solution, the driving roller chain sequentially passes around gear three, two bearings one, and two gears four and meshes with them. The power is effectively transmitted by means of the sprocket transmission structure, making it easy for the rollers to operate synchronously.

[0012] Preferably, the upper end of the fixing rod is fixedly fitted with a bearing, and the bottom end of the outer ring of the bearing is fixedly fitted with a fixing box, the outer wall of the fixing box being fixed to the inner wall of the upper sprocket fixing seat.

[0013] By adopting the above technical solution, the design of bearing two and the fixed box enables the fixed rod one to be stably connected to the upper sprocket fixed seat and rotate flexibly, ensuring the stable operation of the mechanism.

[0014] Preferably, the lower end of the second fixing rod is fixedly fitted with a third bearing, and the bottom end of the outer ring of the third bearing is fixedly fitted with a fixing plate, the bottom end of the fixing plate being fixed to the inner bottom surface of the base.

[0015] By adopting the above technical solution, the design of bearing three and fixed plate ensures that fixed rod two and base are firmly connected and rotate smoothly, thus ensuring stable operation of the mechanism.

[0016] Preferably, a fixing ring is fixed to the upper end of each of the two sprocket drive shafts, and the outer wall of the two fixing rings is fixed to the upper end of the lower sprocket fixing seat.

[0017] By adopting the above technical solution, the fixing ring securely connects the sprocket drive shaft to the lower sprocket fixing seat, thereby enhancing structural stability.

[0018] Preferably, the control mechanism includes a control seat and a rotating shaft rotatably disposed in the middle of the control seat. A bearing is fixedly sleeved in the middle of the rotating shaft at the control seat. A limiting groove is fixedly provided on the concave surface of the control seat. A limiting block that is inserted into the limiting groove is fixedly provided on one side of the middle of the rotating shaft.

[0019] By adopting the above technical solution, the rotating shaft can rotate flexibly in the control seat through the bearing four, and the limit block and the limit groove cooperate to limit the rotation range of the rotating shaft.

[0020] Preferably, a rotating block is fixedly provided at the upper end of the rotating shaft, a steering handle is fixedly provided at the top of the rotating block, and a limiting shell that restricts the movement trajectory of the steering handle is movably sleeved on the outer side of the steering handle.

[0021] By adopting the above technical solution, the design of the rotating shaft, rotating block and steering handle is used to control the direction of the device, and the limiting shell restricts the movement trajectory of the steering handle, so as to achieve fast, accurate and stable steering angle operation.

[0022] In summary, this application includes at least one of the following beneficial technical effects:

[0023] 1. By rotating the steering handle, the first gear is driven, which in turn drives the second gear and the two sprocket drive shafts to rotate under the power transmission of the transmission roller chain. At the same time, it drives the two fourth gears to rotate, thereby controlling the rotation angle of the rollers. The cooperation between the chain, gears, bearings and other components increases the response speed and transmission efficiency of the device.

[0024] 2. By pulling the steering handle upwards, the rotating block moves longitudinally, causing the limiting block to disengage from the limiting groove, thus preparing the steering handle for initial unlocking. Subsequently, the steering handle is rotated to a predetermined angle position and released. The spring's rebound causes the steering handle to quickly engage in the limiting hole, completing the rapid locking and angle calibration of the steering handle. This device simplifies the unlocking and adjustment process of the steering handle, improves operational efficiency, and enhances the convenience and overall stability of the device through angle preset. Attached Figure Description

[0025] Figure 1 This is an isometric schematic diagram of the overall structure of this application;

[0026] Figure 2 This is a frontal axonometric view of part of the structure of this application;

[0027] Figure 3 Figure 2 Enlarged view of point A in the middle;

[0028] Figure 4 Figure 2 Enlarged view at point B in the middle;

[0029] Figure 5 Figure 2 Enlarged view at point C;

[0030] Figure 6 This is a top-view axonometric schematic diagram of the steering mechanism of this application;

[0031] Figure 7 This is a left-side axonometric view of the steering mechanism of this application;

[0032] Figure 8 This is an exploded view of the control mechanism structure of this application.

[0033] Figure 9 This is an exploded view of the rotating shaft portion of this application.

[0034] Reference numerals: 1. Lower sprocket mounting base; 2. Steering mechanism; 3. Control mechanism; 4. Base; 5. Fixing column; 6. Upper sprocket mounting base; 7. Roller; 8. Mounting rod; 9. Handle;

[0035] 201. Rotating rod; 202. Sprocket drive shaft; 203. Bearing 1; 204. Drive roller chain; 205. Fixing ring; 206. Transmission roller chain; 207. Drive shaft 1; 208. Gear 1; 209. Fixing box;

[0036] 210. Bearing II; 211. Fixing Rod I; 212. Gear II; 213. Fixing Rod II; 214. Gear III; 215. Bearing III; 216. Fixing Plate; 217. Gear IV;

[0037] 301. Control base; 302. Rotating shaft; 303. Rotating block; 304. Steering handle; 305. Spring; 306. Bearing 4; 307. Limiting shell; 308. Limiting hole; 309. Limiting groove; 310. Limiting block;

[0038] 311. Slide groove one; 312. Slide groove two; 313. Slider; 314. Threaded hole; 315. Flat head bolt. Detailed Implementation

[0039] The following is in conjunction with the appendix Figure 1 - Figure 9 This application will be described in further detail.

[0040] This application discloses a central control steering linkage mechanism for a mobile C-arm X-ray machine.

[0041] Reference Figure 1A central control steering linkage mechanism for a mobile C-arm X-ray machine includes a lower sprocket fixing seat 1 and a base 4 fixed to one side of the lower sprocket fixing seat 1. Rollers 7 are rotatably mounted on both sides of the lower end of the lower sprocket fixing seat 1, and the rollers 7 are used to drive the entire device to move. A steering mechanism 2 is rotatably mounted on one side of the interior of the base 4, and the steering mechanism 2 is used to transmit power. A fixing column 5 is fixed in the middle of the base 4, and an upper sprocket fixing seat 6 is fixed at the top of the fixing column 5. A control mechanism 3 is rotatably mounted in the middle of one side of the upper sprocket fixing seat 6, and the control mechanism 3 is used to control the direction of the entire device. Handles 9 are fixed on both sides of the upper sprocket fixing seat 6 adjacent to the control mechanism 3, and the handles 9 are used to assist in pushing the entire device to move.

[0042] Before use, the device is installed inside the base 4 and the lower sprocket fixing seat 1, and two rollers 7 are installed on both sides of the lower end of the lower sprocket fixing seat 1. The fixing column 5 and the upper sprocket fixing seat 6 are installed on the top of the base 4 in sequence. The control mechanism 3 is installed inside the upper sprocket fixing seat 6 and connected to the top of the steering mechanism 2. The handle 9 is fixed on both sides of the upper sprocket fixing seat 6. The steering mechanism 2 is driven by rotating the steering handle 304 inside the control mechanism 3, which in turn causes the two rollers 7 to turn. The three positions of the steering handle 304 correspond to the preset angles to which the two rollers 7 are rapidly rotated.

[0043] Reference Figure 2 - Figure 7 The steering mechanism 2 includes a rotating rod 201 and two fixed rods 211 and 213 fixed at both ends of the rotating rod 201. The shapes of the fixed rods 211 and 213 are as follows (e.g., Figure 3 , Figure 4 As shown, gear 212 and gear 3 214 are fixedly sleeved in the middle of fixed rod 1 211 and fixed rod 213. A drive shaft 207 is movably arranged on one side of gear 212. Gear 208 is fixedly sleeved on the outer side of drive shaft 207. A drive roller chain 206 is arranged on the outer side of gear 212 and gear 208. The drive roller chain 206 passes around gear 212 and gear 208 in sequence, and the links of the drive roller chain 206 mesh with the tooth grooves of gear 212 and gear 208.

[0044] Two rollers 7 are each fixedly mounted with a mounting rod 8 at their top ends. The upper ends of the two mounting rods 8 are rotatably connected to the lower ends of the lower sprocket mounting base 1. Gear 4 217 is fixedly sleeved in the middle of the two mounting rods 8. A drive roller chain 204 is provided on the outer side of gear 3 214 and the two gear 4 217. Two sprocket drive shafts 202 are symmetrically distributed inside the lower sprocket mounting base 1 near one of its rollers 7. The opposite axis of the two sprocket drive shafts 202 is parallel to the central axis of the rotating rod 201. Bearing 1 203 is fixedly sleeved on the lower end of each of the two sprocket drive shafts 202. The drive roller chain 204 passes sequentially around gear 3 214, the two bearing 1 203, and the two gear 4 217. Gear 3 214, the two bearing 1 203, and the two gear 4 217 are located on the same horizontal plane, and the chain links of the drive roller chain 204 mesh with the tooth grooves of gear 3 214 and the two gear 4 217. (e.g.) Figure 2 As shown, the upper ends of the two sprocket drive shafts 202 are fixedly fitted with fixing rings 205. The top of the lower sprocket fixing seat 1 is provided with two circular holes at the two fixing rings 205. The outer walls of the two fixing rings 205 are fixed to the inner walls of the two circular holes.

[0045] In use, the transmission shaft 207 drives the gear 208 to rotate, which in turn drives the transmission roller chain 206 to drive the gear 212 to rotate. The gear 212 then drives the fixed rod 211 and the bearing 210 to rotate inside the fixed box 209. The fixed rod 211 then drives the rotating rod 201 and the fixed rod 213 to rotate, thereby transmitting the rotational force of the transmission shaft 207 to the rotating rod 201.

[0046] A bearing 210 is fixedly sleeved on the upper end of the fixing rod 211. The inner wall of the inner ring of the bearing 210 is fixed to the outer wall of the upper end of the fixing rod 211. A fixing box 209 is fixed to the bottom end of the outer ring of the bearing 210. The bottom end of the outer ring of the bearing 210 is fixed to the concave surface of the fixing box 209, and the bearing 210 moves through the middle of the fixing box 209. The outer wall of the fixing box 209 is fixed to the inner wall of the lower sprocket fixing seat 1 by bolts. The fixing rod 213... Bearing 215 is fixedly mounted at the lower end. The inner wall of the inner ring of bearing 215 is fixed to the lower outer wall of fixing rod 213. Fixing plate 216 is fixedly mounted at the bottom of the outer ring of bearing 215. The bottom of the outer ring of bearing 215 is fixed to the top of fixing plate 216. The bottom of fixing plate 216 is fixed to the inner bottom surface of base 4. Both bearing 210 and bearing 215 are deep groove ball bearings composed of inner ring, outer ring and steel ball, used to make bearing 210 rotate quickly.

[0047] The rotation of the fixed rod 213 causes the bearing 215 to rotate at the top of the fixed plate 216, which in turn causes the gear 214 to drive the drive roller chain 204 to rotate. Since the drive roller chain 204 passes around the two bearings 203 and the two gears 217 in sequence, it drives the two bearings 203 and the gears 217 to rotate, thereby causing the mounting rod 8 and the roller 7 to rotate along with the gears 217.

[0048] Reference Figure 8 , Figure 9 The control mechanism 3 includes a control base 301 and a rotating shaft 302 rotatably disposed in the middle of the control base 301. The bottom end of the rotating shaft 302 is fixed to the top end of the transmission shaft 207. A limiting groove 309 is fixedly provided on the concave surface of the control base 301. Three slots are provided between the limiting grooves 309 (the angles of the three slots are: 0° in the middle and ±30° on both sides, corresponding to the roller 7 turning 30° to the left, 0° in the middle, and 30° to the right, respectively), which are used to limit the rotation direction of the steering handle 304. The shape of the limiting groove 309 (e.g., Figure 8 As shown, a limiting block 310 is fixedly provided on one side of the middle part of the rotating shaft 302. The shape of the control seat 301 is adapted to the shape of the slot, and the limiting block 310 is inserted into the middle slot in the initial state. A bearing 306 is fixedly sleeved in the middle of the rotating shaft 302. The outer wall of the outer ring of the bearing 306 is fixed to the inner wall of the control seat 301, and the inner wall of the inner ring of the bearing 306 is fixed to the middle of the outer wall of the rotating shaft 302. The bearing 306 is a deep groove ball bearing composed of an inner ring, an outer ring, and steel balls, used to make the rotating shaft 302 rotate inside the control seat 301.

[0049] By pulling the steering handle 304 upwards, the rotating block 303 moves, causing the limiting block 310 to disengage from the limiting groove 309 and be positioned above it. At this point, the rotation direction of the steering handle 304 is unlocked, allowing it to move upwards from its initial position in the middle of the limiting hole 308. The spring 305 is stretched, rotating the steering handle 304 around the rotating shaft 302 to either side of the limiting hole 308, thus rotating the limiting block 310 into the limiting groove 309. On the same side, when the steering handle 304 is released, the spring 305 rebounds and moves the steering handle 304 downward, so that the steering handle 304 is in the lower part of the limiting hole 308. At the same time, the limiting block 310 is engaged in the slot inside the limiting groove 309 on the same side, thereby making it easy for the steering handle 304 to rotate quickly and lock to a preset angle, and simultaneously driving the roller 7 to rotate quickly to the preset angle. If the steering handle 304 needs to be rotated to other preset angles, simply repeat the lifting and rotating actions of the steering handle 304.

[0050] A rotating block 303 is fixedly sleeved on the upper end of the rotating shaft 302. A steering handle 304 is fixedly mounted on the top of the rotating block 303. A spring 305 is sleeved on the lower end of the steering handle 304. The formula for calculating the elastic force of the spring 305 is F = kx, where F represents the elastic force of the spring 305, k represents the constant of the spring 305, and x represents the compression of the spring 305. A limiting shell 307 is movably sleeved on the outer side of the steering handle 304. The outer side of the spring 305 fits against the inner wall of the limiting shell 307. The two ends of the spring 305 are fixed to the lower outer side of the steering handle 304 and the inner wall of the limiting shell 307, respectively. A limiting hole 308 is opened in the middle of the limiting shell 307. The shape of the limiting hole 308 is as follows (e.g., Figure 8 (As shown).

[0051] In its initial state, the steering handle 304 is located in a groove in the middle of the limiting hole 308. The limiting hole 308 is used to limit the movement trajectory of the steering handle 304 in the rotation state, so that the steering handle 304 can be stabilized after quickly rotating to a predetermined angle. The lower end of the rotating shaft 302 is provided with a first slide groove 311. The inside of the first slide groove 311 is provided with a second slide groove 312. The outer side of the first slide groove 311 is slidably fitted with a slider 313. The outer wall of the slider 313 is fixed to the inner wall of the upper sprocket fixing seat 6. The slider 313 is provided with a threaded hole 314 at the second slide groove 312. The threaded hole 314 is threaded with a flat-head bolt 315. The end of the flat-head bolt 315 inside the second slide groove 312 is unthreaded. The side of the flat-head bolt 315 facing the rotating shaft 302 fits against the inner side of the second slide groove 312. The diameter of the flat-head bolt 315 is the same as the width of the second slide groove 312.

[0052] When the rotating shaft 302 moves upward following the lifting of the rotating block 303, the lower end of the rotating shaft 302 moves inside the slider 313 without detaching from its constraint, because the slider 313 slides inside the first slide groove 311. At the same time, the flat-head bolt 315 slides inside the second slide groove 312 without detaching from its constraint. When the steering handle 304 rotates, the rotating shaft 302 is fitted with a bearing 306 in the middle, which causes the rotating shaft 302 to rotate inside the control seat 301 following the steering handle 304, so that the rotating shaft 302 can simultaneously satisfy both longitudinal movement and rotation functions.

[0053] The implementation principle of the central control steering linkage mechanism of a mobile C-arm X-ray machine according to an embodiment of this application is as follows: each component is installed in sequence. When in use, the steering handle 304 is pulled up and rotated to the target position inside the limiting shell 307 and then released. The spring 305 rebounds and drives the steering handle 304 to remain stable in the limiting hole 308. At the same time, it drives the gear 1 208, gear 212 and transmission roller chain 206 to rotate, and transmits power to the rotating rod 201, which drives the gear 3 214, the two bearings 1 203 and the drive roller chain 204 to rotate. Finally, it drives the two rollers 7 to turn. When it is necessary to change the angle, the actions of pulling and rotating the steering handle 304 are repeated.

[0054] The above are merely optional embodiments of this application and are not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A central control steering linkage mechanism for a mobile C-arm X-ray machine, characterized in that: The device includes a lower sprocket fixing seat (1) and a base (4) fixed on one side of the lower sprocket fixing seat (1). Rollers (7) that drive the entire device to move are rotatably provided on both sides of the lower end of the lower sprocket fixing seat (1). A steering mechanism (2) that transmits power is rotatably provided on one side of the interior of the base (4). A fixing column (5) is fixed in the middle of the base (4). An upper sprocket fixing seat (6) is fixed at the top of the fixing column (5). A control mechanism (3) that controls the movement direction of the entire device is rotatably provided in the middle of one side of the upper sprocket fixing seat (6). Handles (9) for pushing the entire device to move are fixed on both sides of the upper sprocket fixing seat (6) adjacent to the control mechanism (3). The steering mechanism (2) includes a rotating rod (201) and two fixed rods (211 and 213) fixed at both ends of the rotating rod (201). Gear 2 (212) and gear 3 (214) are fixedly sleeved in the middle of the fixed rod 1 (211) and fixed rod 2 (213). Gear 1 (208) is movably arranged on one side of gear 2 (212). A transmission roller chain (206) meshes with the outer side of gear 2 (212) and gear 1 (208).

2. The mobile C-arm X-ray machine central control steering linkage according to claim 1, characterized in that: The top of each of the two rollers (7) is fixedly provided with a mounting rod (8), and a gear four (217) is fixedly sleeved in the middle of the two mounting rods (8). The gear three (214) meshes with the outer side of the two gear four (217) with a drive roller chain (204). The upper ends of the two mounting rods (8) are rotatably set on both sides of the lower end of the lower sprocket fixing seat (1).

3. The mobile C-arm X-ray machine central control steering linkage according to claim 2, characterized in that: The lower sprocket fixing seat (1) has two sprocket drive shafts (202) fixedly installed inside one end near one of its rollers (7). The lower ends of the two sprocket drive shafts (202) are all fixedly fitted with bearings (203). The driving roller chain (204) passes through gear three (214), the two bearings (203) and the two gears four (217) in sequence, and the chain links of the driving roller chain (204) mesh with the tooth grooves of gear three (214) and the two gears four (217).

4. The mobile C-arm X-ray machine central control steering linkage according to claim 1, characterized in that: The upper end of the first fixing rod (211) is fixedly fitted with the second bearing (210), and the bottom end of the outer ring of the second bearing (210) is fixedly fitted with a fixing box (209). The outer wall of the fixing box (209) is fixed to the inner wall of the upper sprocket fixing seat (6).

5. The mobile C-arm X-ray machine central control steering linkage according to claim 1, wherein: The lower end of the second fixing rod (213) is fixedly fitted with a third bearing (215), and the bottom end of the outer ring of the third bearing (215) is fixedly fitted with a fixing plate (216), and the bottom end of the fixing plate (216) is fixed to the inner bottom surface of the base (4).

6. The mobile C-arm X-ray machine central control steering linkage according to claim 3, wherein: The upper ends of the two sprocket drive shafts (202) are each fixed with a retaining ring (205), and the outer walls of the two retaining rings (205) are fixed to the upper end of the lower sprocket fixing seat (1).

7. The mobile C-arm X-ray machine central control steering linkage according to claim 1, wherein: The control mechanism (3) includes a control seat (301) and a rotating shaft (302) rotatably disposed in the middle of the control seat (301). A bearing (306) is fixedly sleeved in the middle of the rotating shaft (302) at the control seat (301). A limiting groove (309) is fixedly provided on the concave surface of the control seat (301). A limiting block (310) that is inserted into the limiting groove (309) is fixedly provided on one side of the middle of the rotating shaft (302).

8. The central control steering linkage mechanism for a mobile C-arm X-ray machine according to claim 7, characterized in that: A rotating block (303) is fixedly provided at the upper end of the rotating shaft (302), and a steering handle (304) is fixedly provided at the top of the rotating block (303). A limiting shell (307) that restricts the movement trajectory of the steering handle (304) is movably sleeved on the outside of the steering handle (304).

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