Adjustable gradient fitness stair machine

Abstract

The application discloses a fitness stair machine with adjustable gradient, which comprises a main frame, a bottom frame, a table frame assembly, a lifting frame mechanism and an electronic table assembly, wherein the rear side of the main frame is rotationally connected with the bottom frame; one end of the table frame assembly is connected with the main frame, and the other end is connected with the electronic table assembly; the lifting frame mechanism is installed between the included angle formed by the main frame and the bottom frame; one end of the lifting frame mechanism is rotationally connected with the bottom of the main frame, and the other end is connected with a gradient adjustment driving mechanism through a pulley frame assembly; pulleys are arranged at the two ends of the pulley frame assembly and can slide along the roller grooves on the two sides of the bottom frame; the main frame comprises a support assembly, a magnetic control wheel assembly, a step assembly and a transmission structure, the magnetic control wheel assembly is fixed in front of the support assembly, and the magnetic control wheel assembly is linked with the step assembly through the transmission structure. The application can realize the function of gradient adjustment, the stair step pedal can be finely adjusted according to the inclination angle of the machine body, and the user experience is better.

Description

Technical Field

[0001] This invention relates to the field of fitness equipment, and in particular to an adjustable incline fitness stair machine. Background Technology

[0002] Today, stair climbers are an important type of aerobic training equipment for home and commercial use. By simulating the motion of climbing stairs, they can accelerate fat burning, increase oxygen consumption, and improve muscle tone in the buttocks and thighs; they also enhance the body's circulatory and metabolic functions. Furthermore, they minimize the risk of injury to the knee and ankle joints. They are widely used in homes, gyms, hotels, and other settings. However, current stair climbers generally only allow for climbing at a fixed incline, without the ability to adjust the incline. Additionally, the stair steps are typically of a fixed height and cannot be fine-tuned to accommodate changes in the machine's incline. Summary of the Invention

[0003] In order to overcome the above-mentioned problems in the prior art, the present invention proposes a fitness stair machine with adjustable slope.

[0004] The technical solution adopted by this invention to solve its technical problem is: an adjustable slope fitness stair machine, including a main frame, a base frame, a welded watch frame assembly, a lifting frame mechanism, and an electronic watch assembly. The base frame is located below the main frame, and the rear side of the main frame is rotatably connected to the base frame. One end of the welded watch frame assembly is connected to the main frame, and the other end is connected to the electronic watch assembly. The lifting frame mechanism is installed between the angle formed by the main frame and the base frame. One end of the lifting frame mechanism is rotatably connected to the bottom of the main frame, and the other end is connected to the slope adjustment drive mechanism through a pulley frame assembly. The pulley frame assembly is provided with pulleys at both ends that slide along the roller grooves on both sides of the base frame.

[0005] The main frame includes a support assembly, a magnetic control wheel assembly, a step assembly, and a transmission structure. The magnetic control wheel assembly is fixed in front of the support assembly and includes an electromagnet and a power-off brake. The magnetic control wheel assembly is linked to the step assembly through the transmission structure.

[0006] The aforementioned adjustable slope fitness stair machine also has a handrail tube installed above the main frame.

[0007] The aforementioned adjustable slope fitness stair machine includes a slope adjustment drive mechanism comprising a motor and a threaded guide rod. The motor is mounted on a base frame, and the motor output shaft is fixedly connected to one end of the threaded guide rod. The other end of the threaded guide rod extends to one end of the base frame. A threaded sleeve is provided on the pulley frame assembly, and the threaded sleeve is fitted onto the threaded guide rod and can slide along the threaded guide rod.

[0008] The aforementioned adjustable slope fitness stair machine includes a lifting frame mechanism comprising two upper toothed plates welded together, two lower toothed plates welded together, a central connecting rod welded together, a central-lower connecting rod welded together, a swing arm welded together, and a lifting frame. One end of each of the two upper toothed plates welded together is rotatably connected to the main frame, and the toothed end of the other end is rotatably connected to the central connecting rod welded together. One end of each of the two lower toothed plates welded together is rotatably connected to the central-lower connecting rod welded together, and the toothed end of the other end is rotatably connected to the central connecting rod welded together and meshes with the toothed end of the upper toothed plates welded together. One end of the lifting frame is rotatably connected to the bottom of the main frame and is connected to the adjacent lower toothed plate welded together via the swing arm welded together. The other end of the lifting frame is rotatably connected to the pulley frame assembly.

[0009] The aforementioned adjustable slope fitness staircase assembly includes a lower connecting frame for the pedal, a pedal assembly, and a connecting plate assembly for the foot pedal. The lower connecting frame for the pedal is rotatably connected to the pedal assembly via a long rod. The lower connecting frame for the pedal is rotatably connected to the connecting plate assembly for the foot pedal via a short rod. The connecting plate assembly for the foot pedal is rotatably connected to the pedal assembly for the foot pedal via a short rod.

[0010] In the aforementioned adjustable slope fitness stair machine, small PU wheels are installed at both ends of the long pole and on both sides of the connecting frame assembly under the pedal.

[0011] The aforementioned adjustable slope fitness stair machine includes a triangular connector and a footboard as the connecting frame assembly. Two triangular connectors are provided, and the two triangular connectors are respectively fixedly connected to both ends of the footboard. The two vertices of the triangular connectors are respectively provided with through holes for connecting short bars and long bars.

[0012] The aforementioned adjustable slope fitness stair machine includes a transmission structure comprising an outer sprocket, an inner sprocket one, a small sprocket, a small chain, a large chain, and an inner sprocket two. The center hole of the inner sprocket two is rotatably connected to a fixed shaft at the connection between the main frame and the base frame. The teeth of the inner sprocket two mesh with the large chain on the step assembly. The large chain extends forward from the main frame and meshes with the inner sprocket one. The center hole of the inner sprocket one is rotatably connected to the inner side of the upper support shaft. The outer side of the upper support shaft is rotatably connected to the center hole of the outer sprocket. The outer sprocket meshes with the small chain. The small chain extends forward from the main frame and meshes with the small sprocket. The center hole of the small sprocket is rotatably connected to the front support shaft. The front support shaft is connected to both sides of the front end of the main frame. The large pulley on the front support shaft is connected to the output shaft pulley of the magnetic control wheel assembly via a transmission belt.

[0013] The beneficial effects of this invention are that a worm gear motor and a threaded guide rod are installed at the bottom of the equipment. The worm gear motor is controlled by an electronic watch to rotate forward and backward, thereby causing the threaded sleeve on the pulley frame to move forward or backward along the threaded guide rod. This allows the body of the fitness stair machine to tilt upward or downward, achieving the function of slope adjustment. Furthermore, the stair step can be finely adjusted according to the tilt angle of the machine body. Attached Figure Description

[0014] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0015] Figure 1 This is a schematic diagram of the lowest state structure of the present invention;

[0016] Figure 2 This is a schematic diagram of the highest state structure of the present invention;

[0017] Figure 3 This is a schematic diagram of the slope adjustment structure of the present invention;

[0018] Figure 4 This is a schematic diagram of the transmission structure of the present invention. Figure 1 ;

[0019] Figure 5 This is a schematic diagram of the transmission structure of the present invention. Figure 2 ;

[0020] Figure 6 This is a schematic diagram of the transmission structure of the present invention. Figure 3 ;

[0021] Figure 7 This is a schematic diagram of the transmission structure of the present invention. Figure 4 ;

[0022] Figure 8 This is a schematic diagram of the pulley frame assembly structure of the present invention;

[0023] Figure 9 This is a schematic diagram of the bracket assembly structure of the present invention;

[0024] Figure 10 This is a schematic diagram of the track assembly welding structure of the present invention;

[0025] Figure 11 This is a schematic diagram of the welded structure of the lower connecting frame of the pedal in this invention;

[0026] Figure 12 This is a schematic diagram of the upper toothed plate welding structure of the present invention;

[0027] Figure 13 This is a schematic diagram of the lower toothed plate assembly welding structure of the present invention;

[0028] Figure 14 This is a schematic diagram of the magnetically controlled wheel assembly structure of the present invention.

[0029] In the diagram: 1. Main frame; 2. Left handrail tube; 3. Right handrail tube; 4. Measuring bracket assembly; 5. Base frame; 6. Lifting frame assembly; 7. Pulley frame assembly; 8. Threaded guide rod; 9. Worm gear motor; 10. Coupling; 11. Bearing housing one; 12. Bearing housing two; 13. Threaded sleeve; 14. Large PU wheel; 15. Small PU wheel; 16. Bracket assembly; 17. Left bracket assembly; 18. Rail assembly; 19. Magnetic control wheel assembly; 20. Upper gear plate assembly; 21. Lower gear plate assembly; 22. Lower pedal connecting frame assembly; 23. Front support shaft; 24. Left outer sprocket; 25. 26. Left inner sprocket 1; 27. Left small sprocket; 28. Left small chain; 29. ​​Left large chain; 20. Left inner sprocket 2; 31. Middle connecting rod assembly; 32. Middle and lower connecting rod assembly; 33. Swing rod assembly; 34. Pedal assembly; 35. Foot pedal connecting plate assembly; 36. Long rod; 37. Short rod; 38. Electronic watch assembly; 39. Track support shaft; 40. Upper support shaft; 41. Lower fixed shaft; 42. Roller groove; 43. Lifting frame; 44. Step assembly; 45. Bearing seat 4; 46. Large pulley; 47. Drive belt; 48. Electromagnet; 49. Power failure brake. Detailed Implementation

[0030] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1-3 As shown in the figure, this embodiment discloses an adjustable slope fitness stair machine. The fitness stair machine mainly includes a main frame 1, a left handrail tube 2, a right handrail tube 3, a meter frame assembly 4, a base frame 5, a lifting frame assembly 6, and an electronic meter assembly 37.

[0032] The main frame includes a support assembly, a magnetic wheel assembly, a step assembly, and a transmission structure, such as... Figure 4-7 As shown, the magnetically controlled wheel assembly is fixed to the front of the bracket assembly, and the magnetically controlled wheel assembly is as follows. Figure 14 As shown, it includes an electromagnet, a power-off brake, and a magnetically controlled wheel assembly that is linked to the step assembly via a transmission structure.

[0033] The base frame 5 is located below the main frame 1 and placed on the ground. The base frame 5 includes a pulley frame assembly 7, a threaded guide rod 8, a worm gear motor 9, a coupling 10, a first bearing seat 11, a second bearing seat 12, and a threaded sleeve 13. The worm gear motor 9 is fixed on the base in the middle of the base frame 5, and the output shaft of the worm gear motor 9 is connected to one end of the coupling 10. The external thread of the threaded guide rod 8 passes through the internal thread of the threaded sleeve 13 on the pulley frame assembly 7, and one end is fixed to the first bearing seat 11, while the other end passes through the second bearing seat 12 and is fixed to the other end of the coupling 10. The structure of the pulley frame assembly 7 is as follows: Figure 8As shown, two large PU wheels 14 and two small PU wheels 15 are fixed on each side, which can roll back and forth in the inner surface of the roller grooves 41 on both sides of the base frame 5.

[0034] The lifting frame assembly 6 is located between the main frame 1 and the base frame 5, serving to support and adjust the main frame 1. This description focuses on the structure of the lifting frame assembly 6 on the left side of the fitness stair machine's operating direction; the structure on the right side is a mirror image of the left side. The left side structure of the lifting frame assembly 6 includes two upper toothed plate welded assemblies 20, two lower toothed plate welded assemblies 21, a middle connecting rod welded 30, a middle and lower connecting rod welded 31, a swing arm welded 32, and a lifting frame 42. The upper toothed plate welded structures and lower toothed plate welded structures are as follows... Figure 12-13 As shown, one end of the two upper toothed plate welded assemblies 20 is respectively shafted to the track support shaft 38 and track support shaft 2 on the main frame 1. The toothed ends of the two upper toothed plate welded assemblies 20 are connected to the two ends of the middle connecting rod welded 30 by bolts. The toothed ends of the two lower toothed plate welded assemblies 21 are also connected to the two ends of the middle connecting rod welded 30 by bolts, and the toothed ends mesh with the toothed ends of the two upper toothed plate welded assemblies 20. The other end of the two lower toothed plate welded assemblies 21 is connected to the two ends of the middle and lower connecting rod welded 31 by bolts. The wider end of the lifting frame 42 is shafted to the bottom of the main frame 1, and is connected to the adjacent lower toothed plate welded assemblies 21 through the two ends of the swing arm welded 32. The narrower end of the lifting frame 42 is shafted to the two ends of the pulley frame assembly 7.

[0035] The main frame 1 includes a support assembly 16, a left support welded assembly 17, a track welded assembly 18, a magnetic control wheel assembly 19, a step assembly 43, a front support shaft 23, a left outer sprocket 24, a left inner sprocket one 25, a left small sprocket 26, a left small chain 27, a left large chain 28, and a left inner sprocket two 29; the support assembly 16 has the following structure: Figure 9 As shown, the track assembly welded 18 structure is as follows Figure 10As shown, only the structure of the main frame 1 on the left side of the fitness stair machine in the direction of use is described here. The structure of the main frame 1 on the right side in the direction of use is a mirror image of the left side structure. The left support assembly 17 on the left side of the main frame 1 in the direction of use has one end of its lower fixed shaft 40 connected to the bearing seat 44 on the rear side of the base frame 5. The inner side of the lower fixed shaft 40 is connected to the center hole of the left inner sprocket 29. The tooth profile of the left inner sprocket 29 meshes with the left large chain 28 on the step assembly 43. The left large chain 28 extends forward of the main frame 1 and meshes with the tooth profile of the left inner sprocket 25. The center hole of the left inner sprocket 25 is connected to the inner side of the upper support shaft 39. The outer side is shaft-connected to the center hole of the left outer sprocket 24. The teeth of the left outer sprocket 24 mesh with the left small chain 27. The left small chain 27 extends forward of the main frame 1 and meshes with the teeth of the left small sprocket 26. The center hole of the left small sprocket 26 is shaft-connected to the left end of the front support shaft 23. Both ends of the front support shaft 23 are connected to the front sides of the main frame 1 through bearing seats. The large pulley 45 on the front support shaft 23 is connected to the output shaft pulley of the magnetic control wheel assembly 19 through the transmission belt 46. The magnetic control wheel assembly 19 is fixed in front of the bracket assembly 16. The magnetic control wheel assembly 19 has an electromagnet 47 and a power failure brake 48. The structure of the lower connecting frame assembly 22 of the pedal is as follows: Figure 11 As shown, the lower connecting frame assembly 22 is connected to the pedal assembly 33 via a long rod 35. Small PU wheels 15 and a left large chain 28 are installed at both ends of the long rod 35. The lower connecting frame assembly 22 is connected to the foot pedal connecting plate assembly 34 via a short rod 36. The foot pedal connecting plate assembly 34 is then connected to the pedal assembly 33 via a short rod 36, thus forming a closed loop structure. In addition to the end connecting the long rod 35 and the short rod 36, the lower connecting frame assembly 22 is also equipped with small PU wheels 15 on both sides, which can circulate and roll back and forth on the inner surfaces of both sides of the track assembly 18. Taking the left side structure of the main frame 1 as an example, the small PU wheels 15 installed on the left side of the long rod 35 can circulate and roll back and forth on the upper surface of the left support assembly 17.

[0036] The through-hole end of the watch frame assembly 4 is shafted into the U-shaped seat above the front end of the main frame 1, and the other end is connected to the electronic watch assembly 37; one end of the left handrail tube 2 and the right handrail tube 3 are shafted into the middle section of the watch frame assembly 4, and the other end is connected to the top of the columns on both sides of the rear of the base frame 5.

[0037] When the incline adjustment function of the fitness stair machine is used, the output shaft of the worm motor 9 is controlled to drive the coupling 10 and the threaded guide rod 8 to rotate clockwise. This causes the internal thread of the threaded sleeve 13 on the pulley frame assembly 7 to move backward along the external thread of the threaded guide rod 8. Consequently, the large PU wheel 14 and the small PU wheel 15 at both ends of the pulley frame assembly 7 roll backward along the roller grooves 41 on both sides of the base frame 5. The roller frame assembly 7 drives the lifting frame 42 to lift the main frame 1 upward. This also drives the swing arm assembly 32, the lower tooth plate assembly 21, the middle and lower connecting rod assembly 31, the middle connecting rod assembly 30, and the upper tooth plate assembly 20, which are connected together, to rotate clockwise within the tooth meshing range of the upper tooth plate assembly 20 and the lower tooth plate assembly 21. This causes the main frame 1 to rotate clockwise with the lower fixed shaft 40 as the center, thereby increasing the incline of the main frame 1. Conversely, by controlling the output shaft of the worm motor 9 to drive the coupling 10 and the threaded guide rod 8 to rotate counterclockwise, the internal thread of the threaded sleeve 13 on the pulley frame assembly 7 moves forward along the external thread of the threaded guide rod 8, thereby causing the large PU wheel 14 and the small PU wheel 15 at both ends of the pulley frame assembly 7 to roll forward along the roller grooves 41 on both sides of the base frame 5; the roller frame assembly 7 drives the lifting frame 42 to lower the main frame 1, and drives the rocker arm assembly welded 32, the lower toothed plate assembly welded 21, the middle and lower connecting rod assembly welded 31, the middle connecting rod assembly welded 30, and the upper toothed plate assembly welded 20, which are connected together, to rotate counterclockwise within the tooth meshing range of the upper toothed plate assembly welded 20 and the lower toothed plate assembly welded 21, so that the main frame 1 rotates counterclockwise with the lower fixed shaft 40 as the center, thereby realizing the function of lowering the slope of the main frame 1.

[0038] When the slope of the main frame 1 increases, the track assembly 18 in the main frame 1 will lift one end of the triangular pedal lower connecting frame assembly 22, which is fixed with a small PU wheel 15, upwards. This will cause the pedal lower connecting frame assembly 22 to rotate clockwise around the end that is axially connected to the long rod 35. Consequently, the end of the pedal lower connecting frame assembly 22 that is axially connected to the short rod 36 will drive the foot pedal connecting plate assembly 34 to flip outwards towards the step assembly 43, thereby lifting the pedal assembly 33 upwards and achieving the function of raising the step height. Conversely, when the slope decreases, the track assembly 18 in the main frame 1 lowers the end of the triangular pedal connecting frame assembly 22 with the small PU wheel 15 fixed thereon, causing the pedal connecting frame assembly 22 to rotate counterclockwise around the end that is axially connected to the long rod 35. This causes the end of the pedal connecting frame assembly 22 that is axially connected to the short rod 36 to drive the foot pedal connecting plate assembly 34 to flip inward toward the step assembly 43, thereby lowering the pedal assembly 33 and reducing the step height.

[0039] When using the training function of the fitness stair machine, the user stands on the footplate assembly 33 of the step assembly 43. In the off-state, the de-energizing brake 48 of the magnetic control wheel assembly 19 is in the engaged braking state, and the step assembly 43 cannot run. When started by the electronic watch assembly 37, the de-energizing brake 48 of the magnetic control wheel assembly 19 is in the disengaged state. The magnetic control wheel assembly 19 can adjust the reaction force of the magnetic control wheel assembly 19 on the user's body weight according to the magnetic force of the control electromagnet 47 on the cast iron flywheel, thereby realizing the function of controlling the training resistance of the fitness stair machine. During training, the user's weight causes the output shaft pulley of the magnetic control wheel assembly 19 to rotate clockwise in one direction. This rotation, via the transmission belt 46, drives the large pulley 45 on the front support shaft 23 to rotate clockwise backward. This, in turn, drives the left small sprocket 26 on the front support shaft 23 to rotate clockwise backward. The left small sprocket 26, via the left small chain 27, drives the left outer sprocket 24 and the first left inner sprocket 25 to rotate clockwise backward. The first left inner sprocket 25, via the left large chain 28, drives the second left inner sprocket 29 to rotate clockwise backward. All the long rods 35 on the step assembly 43 also rotate clockwise backward via the left large chain 28. This achieves the step-climbing training function of the fitness stair machine. Only the transmission structure on the left side of the fitness stair machine in the direction of use is described here. The transmission structure on the right side, except for the magnetic control wheel assembly 19 and the large pulley 45, is a mirror image of the left side structure.

[0040] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered to fall within the scope of protection of the present invention.

Claims

1. An adjustable incline stair climber machine, characterized by, The utility model provides a kind of health-care building stair machine, including main frame, chassis, table frame group welding, lifting frame mechanism, electronic watch assembly, the chassis is located below main frame, the rear side of main frame is rotatably connected with chassis;The table frame group welding one end is connected with main frame, the other end is connected with electronic watch assembly, the lifting frame mechanism is installed between the included angle formed by main frame and chassis;The lifting frame mechanism one end is rotatably connected with the bottom of main frame, the other end is connected with gradient adjustment drive mechanism by pulley frame assembly;The pulley frame assembly both ends are provided with pulley along the sliding groove of the roller of the both sides of chassis; The main frame includes support assembly, magnetic control wheel assembly, step assembly, transmission structure, the magnetic control wheel assembly is fixed in the front of support assembly, the magnetic control wheel assembly includes electromagnet, power-off brake, the magnetic control wheel assembly is linked with step assembly by transmission structure; The gradient adjustment drive mechanism includes motor, threaded guide rod, the motor is installed on the chassis, the motor output shaft is fixedly connected with one end of threaded guide rod, the other end of threaded guide rod extends to one end of the chassis, the pulley frame assembly is provided with threaded sleeve, the threaded sleeve is sleeved on threaded guide rod and can slide along threaded guide rod; The step assembly includes pedal lower connecting frame group welding, pedal group welding, foot pedal middle connecting plate group welding, the pedal lower connecting frame group welding is rotatably connected with pedal group welding by long rod, the pedal lower connecting frame group welding is rotatably connected with foot pedal middle connecting plate group welding by short rod, the foot pedal middle connecting plate group welding is rotatably connected with foot pedal plate group welding by short rod; The long rod both ends, pedal lower connecting frame group welding both sides are all installed with small PU wheel; The pedal lower connecting frame group welding includes triangular connecting piece, pedal, the triangular connecting piece is provided with two, two the triangular connecting piece is fixedly connected at pedal both ends respectively, two apexes of the triangular connecting piece are provided with through hole for connecting short rod and long rod respectively; When the gradient adjustment function of health-care building stair machine is used, the output shaft of motor drives coupling and threaded guide rod to rotate clockwise, the internal thread of threaded sleeve on pulley frame assembly moves backward along the external thread of threaded guide rod, and then the large PU wheel and small PU wheel at both ends of pulley frame assembly roll backward along the roller groove of both sides of chassis;The pulley frame assembly drives lifting frame to lift main frame upward, and drives swing lever group welding, lower tooth plate group welding, middle lower connecting rod group welding, middle connecting rod group welding, upper tooth plate group welding to rotate clockwise in the tooth shape meshing range of upper tooth plate group welding and lower tooth plate group welding, so that main frame rotates clockwise around the fixed shaft below, to realize the function of raising the gradient of main frame; When the gradient of main frame rises, the track group welding in main frame will lift the one end of pedal lower connecting frame group welding with small PU wheel upward when the gradient rises, so that pedal lower connecting frame group welding rotates clockwise around the one end of long rod shaft connection, and then the one end of pedal lower connecting frame group welding with short rod shaft connection drives foot pedal middle connecting plate group welding to turn over outside step assembly, and then pedal group welding is lifted upward, to realize the function of raising the height of step.

2. The step mill of claim 1, wherein, Handrail pipe is further installed above the main frame.

3. The step mill of claim 1, wherein, The lifting frame mechanism comprises two upper tooth plate group weldings, two lower tooth plate group weldings, a middle connecting rod group welding, a middle lower connecting rod group welding, a swing rod group welding and a lifting frame, one end of each of the two upper tooth plate group weldings is rotationally connected with the main frame, and the other end is rotationally connected with the middle connecting rod group welding; one end of each of the two lower tooth plate group weldings is rotationally connected with the middle lower connecting rod group welding, and the other end is rotationally connected with the middle connecting rod group welding and engaged with the toothed end of the upper tooth plate group welding; one end of the lifting frame is rotationally connected with the bottom of the main frame, and the other end is rotationally connected with the pulley frame assembly through the swing rod group welding.

4. The step mill of claim 1, wherein, The transmission structure comprises an outer chain wheel, an inner chain wheel one, a small chain wheel, a small chain, a large chain and an inner chain wheel two, the inner chain wheel two is rotationally connected with the fixed shaft at the connection between the main frame and the bottom frame, the teeth of the inner chain wheel two are engaged with the large chain on the step assembly, the large chain extends to the front of the main frame and is engaged with the inner chain wheel one, the center hole of the inner chain wheel one is rotationally connected with the inner side of the upper support shaft, the outer side of the upper support shaft is rotationally connected with the center hole of the outer chain wheel, the outer chain wheel is engaged with the small chain, the small chain extends to the front of the main frame and is engaged with the small chain wheel, the center hole of the small chain wheel is rotationally connected with the front support shaft, the front support shaft is connected with the two sides of the front end of the main frame, and the large belt pulley on the front support shaft is connected with the belt pulley of the magnetic control wheel assembly output shaft through a transmission belt.

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