An obstacle-crossing wheelchair

Abstract

The present invention discloses an obstacle-crossing wheelchair, belonging to the technical field of wheelchairs, which includes a wheelchair main body, a driving mechanism, an obstacle-crossing mechanism, and a center-of-gravity adjustment mechanism. In the present invention, the ratchet and pawl of the driving mechanism cooperate to achieve one-way rotation. The user obtains the driving force for the wheels to rotate forward by continuously swinging the handle, which is simple and labor-saving to operate and has a wider audience; the obstacle-crossing mechanism first touches the obstacle protrusion through the obstacle-crossing wheel to play a supporting role and assist the wheels to cross obstacles, especially suitable for common first-level obstacle crossing; the center-of-gravity adjustment mechanism cooperates with the obstacle-crossing mechanism to keep the wheelchair seat lifted or lowered horizontally, adaptively adjust the center of gravity, and can achieve a comfortable, efficient, and safe obstacle-crossing function.

Description

Technical Field

[0001] The present invention relates to the technical field of wheelchairs, and the disclosed content relates to a wheelchair, and more particularly to an obstacle-crossing wheelchair. Background Art

[0002] Electric wheelchairs are easy to operate, require little effort, and offer high mobility, but they are expensive and have poor battery life. Manual wheelchairs are portable, cost-effective, and economical, but they require a caregiver to assist with overcoming obstacles. Common wheelchairs on the market come in three types: motor-driven wheelchairs, tracked wheelchairs, and leg-driven wheelchairs. These wheelchairs utilize a motor-driven mechanism to help users navigate obstacles more easily. Planetary wheelchairs are the most common and researched type of wheelchair worldwide. They are currently the most effective wheelchair for stair climbing, adapting to various staircases and difficult terrain.

[0003] However, due to the safety limitations of wheeled motion when navigating obstacles, these wheelchairs typically require more complex balance control mechanisms and safety protection mechanisms to smoothly navigate obstacles. Even so, most wheeled barrier-free wheelchairs still require dedicated personnel for protection when navigating obstacles. Furthermore, the vast majority of obstacle-crossing wheelchairs are designed to navigate continuous, multi-level obstacles. While most obstacle-crossing wheelchairs utilize star-shaped wheels, while effective at overcoming obstacles, they can also cause significant jolts. This sacrifices some of the comfort of use on flat surfaces in order to achieve continuous, multi-level obstacle navigability. Consequently, the problem of overcoming single-height obstacles, which often occur on flat surfaces, has not been thoroughly studied or addressed.

[0004] Considering that many physically disabled people who use wheelchairs can move their upper limbs flexibly, the design of a wheelchair that can overcome obstacles by itself can meet the needs of disabled people for independent travel and help people with lower limb disabilities solve the problem of small-scale free and independent activities in daily life.

[0005] Common wheelchairs on the market generally have the following problems:

[0006] (1) Electric wheelchairs are labor-saving but expensive. Manual wheelchairs use the user's arms to push the wheelchair wheels, which is time-consuming and labor-intensive. Over time, it can cause damage to the user's hands, shoulders, and cervical spine.

[0007] (2) Most wheelchairs are designed for walking on flat ground and overcoming continuous multi-level obstacles. There is no good solution for overcoming the common flat ground obstacles during wheelchair use;

[0008] (3) When a wheelchair overcomes an obstacle, its center of gravity tilts backward, and the user is prone to falling backward and tipping over. A common solution is to install anti-tipping wheels on the rear side of the wheelchair. However, if the anti-tipping wheels break from the wheelchair, there is a huge safety hazard, and the problem of the center of gravity tilting backward is not fundamentally solved.

[0009] The Chinese invention patent with the patent number CN102614055B discloses a wheel / track coupled self-balancing barrier-free wheelchair, specifically discloses a wheelchair composed of an upper frame, a lower frame, a main frame, a lower limb frame, an auxiliary wheel frame, auxiliary wheels, a center of gravity balance mechanism, and a wheel / track variable structure mobile platform. The elastic track that unfolds outward enables the mobile platform to convert from wheeled movement to tracked movement, thereby making it easier for the wheelchair to go up and down stairs. The angle of the backrest and the seat is adjusted through the center of gravity balance mechanism to adjust the center of gravity, so that the wheelchair maintains a certain balance. However, the structure of the wheel / track transformation is too complex, with high production difficulty, large weight, inconvenient use and not suitable for daily life; by adjusting the angle of the backrest and changing the posture of the user to adjust the center of gravity, the comfort level for the user is poor, and it is even unusable for patients with upper limb injuries, especially those with inconvenient waist movement.

[0010] In summary, the labor-saving manual obstacle-crossing wheelchair of the present invention utilizes the lever principle and is equipped with a balance mechanism that can adaptively adjust the center of gravity, which can achieve comfortable, efficient and safe obstacle-crossing functions, and at the same time meet the humanized needs of independent travel without caregivers and good adaptability to road surface environments. Summary of the Invention

[0011] In order to overcome at least one of the above-mentioned disadvantages, the present invention provides an obstacle-crossing wheelchair. The object of the present invention can be achieved by adopting the following technical solutions:

[0012] An obstacle-crossing wheelchair, including a wheelchair main body, the wheelchair main body includes a frame and a seat, wheels are arranged on the left and right sides of the frame, and a driving mechanism and an obstacle-crossing mechanism are further included;

[0013] The driving mechanism is symmetrically arranged on the left and right sides of the frame and is connected to the wheels, and the driving mechanism can drive the wheels to rotate and move forward;

[0014] The obstacle-crossing mechanism includes an internally meshing step wheel assembly, an obstacle-crossing wheel and a lower pair mechanism. The internally meshing step wheel assembly is connected to the wheels. The internally meshing step wheel assembly includes an externally meshing gear and an internally meshing gear. The obstacle-crossing wheel is located in front of the advancing direction of the wheels;

[0015] The driving mechanism drives the wheels and the externally meshing gear to rotate. The externally meshing gear drives the internally meshing gear to rotate and cooperates with the lower pair mechanism to drive the obstacle-crossing wheel to rotate; so that the obstacle-crossing wheel can abut against the top surface of the protruding obstacle to serve as a fulcrum to assist the wheels in crossing obstacles.

[0016] Preferably, the driving mechanism includes a ratchet mechanism and a pawl mechanism that are unidirectionally meshed. The ratchet mechanism can rotate unidirectionally, and the ratchet mechanism and the pawl mechanism cooperate to drive the wheels to rotate.

[0017] Preferably, a wheel main shaft is connected to the axial center position of the wheel and the axial center position of the pawl mechanism. The pawl mechanism includes a pawl rotating shaft, a pawl support, a torsion spring, and a pawl member. The ratchet mechanism includes a ratchet handle. The tooth groove of the ratchet handle is in one-way engagement with the pawl member. The ratchet handle swings back and forth to drive the wheel to rotate unidirectionally in cooperation with the pawl member.

[0018] Preferably, the wheel main shaft is connected to the external gear, and the external gear rotates under the drive of the drive mechanism.

[0019] Preferably, the movement track of the obstacle-crossing wheel during rotational movement is an ellipse and is in the same direction as the rotation direction of the wheel. The obstacle-crossing wheel is always located on the front side of the advancing direction of the wheel, and the horizontal height of the bottom of the obstacle-crossing wheel is always higher than the horizontal height of the bottom of the wheel.

[0020] Preferably, the lower pair mechanism includes a frame rod, a rocker, a connecting rod, and a crank. The frame rod, the crank, the connecting rod, and the rocker are sequentially connected end to end in a rotating manner.

[0021] Preferably, the frame rod is connected to the internal gear to fix the relative positions of the external gear and the internal gear. One end of the frame rod is connected to the internal gear.

[0022] One end of the crank is connected to the internal gear. The crank rotates synchronously under the drive of the internal gear. The other end of the crank is rotatably connected to the connecting rod.

[0023] The obstacle-crossing wheel is arranged on the connecting rod. The other end of the connecting rod is rotatably connected to the rocker.

[0024] Preferably, the obstacle-crossing wheelchair further includes a center-of-gravity adjustment mechanism and an auxiliary wheel. The center-of-gravity adjustment mechanism includes a lifting mechanism and a balancing mechanism. The auxiliary wheel is arranged below the balancing mechanism.

[0025] During the obstacle-crossing process of the wheelchair main body, the lifting mechanism lifts and supports the front end of the seat. The balancing mechanism supports the rear end of the seat under the drive of the lifting mechanism. The seat is vertically lifted and maintained in a horizontal state under the support of the lifting mechanism and the balancing mechanism.

[0026] After the wheelchair main body crosses the obstacle, the lifting mechanism and the balancing mechanism return to their original positions, and the seat vertically descends and maintains a horizontal state.

[0027] Preferably, the lifting mechanism includes a front support rod, a first pulley, a lifting chute, and a lifting support rod.

[0028] The lifting chute is arranged horizontally, one end of the front support rod is connected to the front bottom of the seat, and the other end of the front support rod is connected to the first pulley. The first pulley can slide horizontally in the lifting chute, and the two ends of the lifting support rod are respectively rotatably connected to the first pulley and the auxiliary wheel.

[0029] Preferably, the balancing mechanism includes a rear support rod, a second pulley, a balancing chute, and a third pulley;

[0030] The balancing slide is vertically arranged, and the rear support rod slides up and down in the balancing slide. One end of the rear support rod is connected to the second pulley, and the second pulley rests against the rear end bottom of the seat. The other end of the rear support rod is connected to the third pulley in the balancing slide.

[0031] Beneficial technical effects of the present invention:

[0032] (1) The obstacle-crossing wheelchair converts the rotation of the wheelchair wheels driven by the arms pushing the hand wheelchair into the forward movement of the ratchet handle by the arms. The user can transfer kinetic energy to the main shaft by continuously swinging the handle, so that the main shaft obtains the driving force to rotate forward, and the wheels can continuously roll forward to achieve forward movement and / or steering, thereby reducing the range of arm movement and lowering the user's driving force threshold. Driving the wheelchair is simpler and more labor-saving. Since the range of handle rotation is not limited, it is suitable for users of different body proportions.

[0033] (2) The obstacle-crossing wheelchair adopts the lever principle. The ratchet handle, pawl mechanism, internal meshing step wheel assembly and low-pair mechanism cooperate with each other to drive the obstacle-crossing wheel to form a fulcrum on the obstacle protrusion, allowing the patient to independently, manually and easily complete the obstacle crossing, especially the common first-order obstacle crossing on flat roads, while ensuring the stability and comfort of traveling on flat roads; when crossing obstacles, the vertical height between the tire wheel and the ground is gradually reduced through the running track of the obstacle-crossing wheel, so that the wheel can smoothly cross the obstacle, reducing the user's discomfort and impact when crossing the obstacle;

[0034] (3) The obstacle-crossing wheelchair is based on the balance mechanism of dynamic center of gravity and the principle of torque balance. When crossing obstacles, the front end of the wheelchair is raised, and the dynamic balance of the center of gravity is controlled by the mechanism to lift the rear end of the wheelchair seat to keep the wheelchair seat always in a horizontal state, fundamentally solving the problem of the center of gravity shifting and the wheelchair tilting backward, ensuring that the patient is safe and reliable when using the wheelchair to cross obstacles. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In the accompanying drawings, the following are given by way of example and not limitation:

[0036] Figure 1 and Figure 2 Shows a schematic diagram of the overall structure of the present invention;

[0037] Figure 3 A schematic diagram showing the direction of motion trajectory of the driving mechanism of the present invention is shown;

[0038] Figure 4 and Figure 5 A schematic diagram of the connection structure of the ratchet mechanism and the pawl mechanism of the present invention is shown;

[0039] Figure 6 It shows a schematic structural diagram of the obstacle crossing mechanism of the present invention;

[0040] Figure 7 It shows the front view of the connection structure of the internal meshing step wheel assembly, obstacle crossing wheel and low pair mechanism of the present invention;

[0041] Figure 8 A side view of the connection structure of the internal meshing step wheel assembly, obstacle crossing wheel and low pair mechanism of the present invention is shown;

[0042] Figure 9 It shows a schematic diagram of the obstacle crossing mechanism structure of the present invention when traveling on flat ground;

[0043] Figure 10 A schematic diagram of the structure of the obstacle-crossing mechanism of the present invention is shown;

[0044] Figure 11 It shows a schematic diagram of the obstacle-crossing mechanism structure after the obstacle is crossed in the present invention;

[0045] Figure 12 A schematic diagram showing the structural changes of the center of gravity adjustment mechanism before and during obstacle crossing of the present invention is shown;

[0046] Figure 13 Shows a schematic structural diagram of the center of gravity adjustment mechanism of the present invention;

[0047] Figure 14 A schematic diagram showing the movement direction of the center of gravity adjustment mechanism of the present invention when overcoming obstacles is shown.

[0048] In the picture:

[0049] 1. Wheelchair body; 11. Wheel spindle;

[0050] 2. Driving mechanism; 21. Ratchet mechanism; 22. Pawl mechanism;

[0051] 211, ratchet handle; 221, ratchet shaft; 222, ratchet support; 223, torsion spring;

[0052] 224, ratchet member;

[0053] 3. Obstacle crossing mechanism; 31. Internal meshing step wheel assembly; 32. Obstacle crossing wheel; 33. Low pair mechanism;

[0054] 311, external gear; 312, internal gear;

[0055] 331. Frame rod; 332. Rocker; 333. Connecting rod; 334. Crank

[0056] 4. Auxiliary wheel

[0057] 5. Center of gravity adjustment mechanism; 51. Lifting mechanism; 52. Balancing mechanism

[0058] 511. Front support rod; 512. First pulley; 513. Lifting chute; 514. Lifting support rod

[0059] 521. Rear support rod; 522. Second pulley; 523. Balancing chute; 524. Third pulley Detailed implementation mode

[0060] In the following detailed disclosure, reference is made to the accompanying drawings, and through a part of its features, as illustrations of specific implementable embodiments, these embodiments are fully described. To make the technical solutions of the present invention clearer and more definite for those skilled in the art, the described implementation manners are not limited thereto. The present invention will be further described in detail below with reference to the embodiments and the accompanying drawings.

[0061] As Figure 1 shown, the obstacle - crossing wheelchair includes a wheelchair main body 1. The wheelchair main body 1 includes a frame and a seat. Wheels are arranged on the left and right sides of the frame. It further includes a driving mechanism 2 and an obstacle - crossing mechanism 3. The driving mechanism 2 is symmetrically arranged on the left and right sides of the frame and is connected to the wheels. The driving mechanism 2 can drive the wheels to rotate and move forward.

[0062] As Figure 3 shown, the driving mechanism 2 includes a ratchet mechanism 21 and a pawl mechanism 22 that are meshed unidirectionally. The ratchet mechanism 21 can rotate unidirectionally, and the ratchet mechanism 21 and the pawl mechanism 22 cooperate to drive the wheels to rotate.

[0063] As Figure 3 - Figure 5 shown, a wheel main shaft 11 is connected between the axial center position of the wheel and the axial center position of the pawl mechanism 22. The pawl mechanism 22 includes a pawl rotating shaft 221, a pawl support 222, a torsion spring 223, and a pawl member 224. The ratchet mechanism 21 includes a ratchet handle 211. The tooth groove of the ratchet handle 211 and the pawl member 224 are meshed unidirectionally. The forward and backward swing of the ratchet handle 211 cooperates with the pawl member 224 to drive the wheel to rotate unidirectionally.

[0064] The wheel main shaft 11 is connected to an external gear 311. The external gear 311 rotates under the drive of the driving mechanism 2. The ratchet mechanism 21 is also installed on the flange outside the ratchet handle 211, and the flange is fixed outside the ratchet handle 211 by screws to prevent the separation between the ratchet handle 211 and the pawl member 224.

[0065] The driving mechanism 2 mainly consists of a ratchet handle 211, a ratchet pawl member 224, a ratchet pawl support 222, and a torsion spring 223. It cooperates with the wheel spindle 11 to achieve one-way transmission. The torsion spring 223 forces the ratchet pawl member 224 to remain in contact with the tooth groove of the ratchet handle 211. When the ratchet handle 211 rotates forward, the force generated by the stretching of the torsion spring 223 enables the ratchet pawl member 224 to cooperate with the ratchet handle 211. At this time, the movement of the ratchet handle 211 drives the rotation of the wheel spindle 11. When the ratchet handle 211 rotates backward, the ratchet member 224 compresses the torsion spring 223, making it impossible for the ratchet pawl member 224 to cooperate with the ratchet handle 211. At this time, the movement of the ratchet handle 211 cannot drive the rotation of the wheel spindle 11, and the wheel rotates forward unidirectionally during the forward and backward swinging of the ratchet handle 211.

[0066] During use, the user can continuously swing the ratchet handle 211 to transfer kinetic energy to the wheel spindle 11, so that the wheel spindle 11 obtains the driving force for forward rotation, and the wheel can continuously roll forward. Due to the symmetrically separated structural characteristics of the wheel spindle 11, when the swinging frequencies or angles of the left and right ratchet handles 211 are different, the wheelchair can complete a turn. The advantage of this driving mechanism 2 is its good universality, reducing the range of arm movement, lowering the user's driving force threshold, making it easier and more labor-saving to drive the wheelchair forward. Since the rotation amplitude of the handle is not limited, it can be adapted for users with different body proportions.

[0067] As Figure 6 - Figure 8 shown, the obstacle-crossing mechanism 3 includes an internally meshing step wheel assembly 31, an obstacle-crossing wheel 32, and a lower pair mechanism 33. The internally meshing step wheel assembly 31 is connected to the wheel. The internally meshing step wheel assembly 31 includes an externally meshing gear 311 and an internally meshing gear 312. The obstacle-crossing wheel 32 is located on the front side of the wheel's advancing direction.

[0068] The driving mechanism 2 drives the wheel and the externally meshing gear 311 to rotate. The externally meshing gear 311 drives the internally meshing gear 312 to rotate and cooperates with the lower pair mechanism 33 to drive the obstacle-crossing wheel 32 to perform a rotary motion; so that the obstacle-crossing wheel 32 can abut against the top surface of the protruding obstacle to serve as a fulcrum to assist the wheel in crossing the obstacle.

[0069] The movement trajectory of the rotary motion of the obstacle-crossing wheel 32 is an ellipse and is in the same direction as the rotation direction of the wheel. The obstacle-crossing wheel 32 is always located on the front side of the wheel's advancing direction, and the horizontal height at the bottom of the obstacle-crossing wheel 32 is always higher than the horizontal height at the bottom of the wheel.

[0070] The internal gear 312 is used as the rim of the driving wheel, and the external gear 311 meshes with it. The wheel spindle 11 transmits kinetic energy to this mechanism through key fitting. The relative position of the external gear is fixed by the frame rod 331 fixed on the front support rod 511. Subsequently, the movement path of the obstacle-crossing wheel 32 is designed through the lower pair mechanism 33. When an obstacle is encountered, the obstacle-crossing wheel 32 first lifts to touch the height plane of the obstacle protrusion, and then drops and rotates. By changing the distance between its axis and the axis of the wheel spindle 11 in the vertical direction, it assists the wheel to cross the obstacle.

[0071] When the obstacle-crossing wheel 32 first lifts to touch the height plane of the obstacle protrusion, the distance between the axis of the obstacle-crossing wheel 32 and the axis of the wheel spindle 11 is relatively large. Subsequently, during the process of the obstacle-crossing wheel 32 dropping and rotating, the distance between the axis of the obstacle-crossing wheel 32 and the axis of the wheel spindle 11 gradually shortens. Due to the frictional force generated by the contact between the obstacle-crossing wheel 32 and the obstacle protrusion plane, during the rotation of the wheel spindle 11 to drive the wheel to rotate, the contact position between the obstacle-crossing wheel 32 and the obstacle protrusion plane forms a fulcrum. At the same time, as the distance between the axis of the obstacle-crossing wheel 32 and the axis of the wheel spindle 11 gradually shortens, the ground clearance distance of the axis of the wheel spindle 11 in the vertical direction also shortens accordingly. The obstacle-crossing wheel 32 can assist the wheel to leap onto the obstacle protrusion plane, and at the same time, the wheel can fall relative to the ground at a relatively uniform speed and contact the ground, playing a buffering role in the wheelchair's descent after crossing the obstacle, improving the comfort of crossing the obstacle, and reducing the impact force on the user.

[0072] As Figure 6 - Figure 8 shown, the lower pair mechanism 33 includes a frame rod 331, a rocker 332, a connecting rod 333, and a crank 334. The frame rod 331, the crank 334, the connecting rod 333, and the rocker 332 are sequentially and rotatably connected end to end.

[0073] The frame rod 331 is connected to the internal gear 312 and fixes the relative positions of the external gear 311 and the internal gear 312. One end of the frame rod 331 is connected to the internal gear 312; one end of the crank 334 is connected to the internal gear 312, and the crank 334 rotates synchronously under the drive of the internal gear 312. The other end of the crank �4 is rotatably connected to the connecting rod 333; the obstacle-crossing wheel 32 is arranged on the connecting rod 333, and the other end of the connecting rod 333 is rotatably connected to the rocker 332.

[0074] As Figure 9 - Figure 11 shown, the positions and movement trajectories of the obstacle-crossing wheel 32 of the obstacle-crossing mechanism 3 before, during, and after crossing the obstacle. The tire of the wheel is arranged outside the external gear 311. When the wheel rotates forward, the external gear 311 rotates accordingly. The external gear 311 drives the internal gear 312 meshing with it to rotate. The crank 334 rotates synchronously with the internal gear 312. The position of the frame rod 331 is fixed to keep the phase positions of the external gear 311 and the internal gear 312 unchanged. When the crank 334 rotates, it drives the rocker 332 and the connecting rod 333 to move accordingly, thereby driving the obstacle-crossing wheel 32 to perform an arc movement back and forth.

[0075] The running trajectory of the obstacle-crossing wheel 32 is designed by the four-bar lengths of the lower pair mechanism 33. The obstacle-crossing wheel 32 runs along an elliptical trajectory and rotates in the same direction as the wheel, enabling the obstacle-crossing wheel 32 to protrude beyond the radius of the wheel when moving forward, crossing the wheel to contact the obstacle protrusion first, and always being higher than the bottom surface of the wheel during rotation. When traveling on a flat road surface, the obstacle-crossing wheel 32 never touches the ground and does not hinder the normal progress of the wheelchair on the flat road surface. The obstacle-crossing wheel 32 can be made of a rubber tire, which plays a role in buffering the fall when crossing obstacles.

[0076] The motion trajectory of the obstacle-crossing wheel 32 is related to the positions and dimensions of the wheel, the obstacle-crossing wheel 32, the external gear 311, the internal gear 312, and the four bars of the lower pair mechanism 33. The present invention provides an embodiment that can achieve the above-mentioned required motion trajectory of the obstacle-crossing wheel 32. This embodiment is only a preferred embodiment of the present invention and is not used to limit the specific dimensions and shapes of the present invention.

[0077] Embodiment:

[0078] External gear 311: φ570mm, module m = 10, number of teeth z = 50;

[0079] Internal gear 312: φ190mm, module m = 10, number of teeth z = 17; s

[0080] Wheel tire: φ630mm;

[0081] Obstacle-crossing wheel 32: φ120mm;

[0082] The included angle between the front support rod 511 and the frame rod 331 is 150°;

[0083] The axial center distance L1 between the two ends of the frame rod 331 is 165mm;

[0084] The axial center distance L2 between the two ends of the rocker 332 is 250mm; s

[0085] T-shaped connecting rod 333: the bottom width and the axial center distance L3 = 160mm, and the vertical distance L4 from the axial center of the obstacle-crossing wheel 32 to the bottom width is 80mm;

[0086] The axial center distance L5 between the two ends of the crank 334 is 55mm.

[0087] As Figure 2 and Figure 12As shown in the figure, the obstacle - climbing wheelchair further includes a center - of - gravity adjustment mechanism 5 and auxiliary wheels 4. The center - of - gravity adjustment mechanism 5 includes a lifting mechanism 51 and a balancing mechanism 52, and the auxiliary wheels 4 are arranged below the balancing mechanism 52. During the obstacle - climbing process of the wheelchair, the lifting mechanism 51 lifts and supports the front end of the seat. The balancing mechanism 52, driven by the lifting mechanism 51, supports the rear end of the seat. The seat is vertically lifted and maintained in a horizontal state under the support of the lifting mechanism 51 and the balancing mechanism 52. After the wheelchair body 1 crosses the obstacle, the lifting mechanism 51 and the balancing mechanism 52 return to their original positions, and the seat vertically descends and maintains a horizontal state.

[0088] As Figure 13 shown, the lifting mechanism 51 includes a front support rod 511, a first pulley 512, a lifting chute 513, and a lifting support rod 514. The lifting chute 513 is horizontally arranged. One end of the front support rod 511 is connected to the bottom of the front end of the seat, and the other end of the front support rod 511 is connected to the first pulley 512. The first pulley 512 can slide horizontally in the lifting chute 513. Both ends of the lifting support rod 514 are respectively rotatably connected to the first pulley 512 and the auxiliary wheel 4.

[0089] The balancing mechanism 52 includes a rear support rod 521, a second pulley 522, a balancing chute 523, and a third pulley 524. The balancing chute 523 is vertically arranged. The rear support rod 521 slides up and down in the balancing chute 523. One end of the rear support rod 521 is connected to the second pulley 522, and the second pulley 522 abuts against the bottom of the rear end of the seat. The other end of the rear support rod 521 is connected to the third pulley 524 in the balancing chute 523.

[0090] When the wheelchair crosses an obstacle, the front end is lifted, generating an inclination angle. If the center of gravity of the seat is not adjusted, with the auxiliary wheel 4 as the fulcrum, when the user's center of gravity tilts backward, the torque generated at the pressure - bearing part of the backrest may cause the wheelchair to tip over. Generally, wheelchairs adopt the method of installing rear anti - tipping wheels, but this can only avoid problems to a certain extent and cannot fundamentally solve the problem.

[0091] As Figure 14Schematic diagram of the movement direction of the center-of-gravity adjustment mechanism 5 when the wheelchair crosses an obstacle. The center-of-gravity adjustment mechanism 5 is composed of rods, pulleys and chutes. When crossing an obstacle, the obstacle-crossing wheel 32 abuts against the plane of the obstacle protrusion, and the lifting support rod 514 rotates around the axle of the auxiliary wheel 4, causing the front support rod 511 to lift vertically. At the same time, through the cooperation of the first pulley 512 and the lifting chute 513, the first pulley 512 slides along the lifting chute 513 towards the rear end of the wheelchair, and the front support rod 511 drives the seat to move synchronously towards the rear end of the wheelchair. The rising height of the lifting chute 513 causes the rear support rod 521 to lift vertically at the same rate along the balance chute 523. The second pulley 522 always supports the bottom of the seat, and the seat can move horizontally along the second pulley 522. The distance between the bottom surface of the rear end of the seat and the lifting chute 513 is always consistent with the height of the front support rod 511, thereby ensuring that the seat remains horizontal during the obstacle-crossing process. By maintaining the dynamic self-adaptive adjustment of the center of gravity through the center-of-gravity adjustment mechanism 5, the center of gravity of the human body and the center of gravity of the wheelchair are always on the same vertical line, avoiding the problem of the wheelchair tilting backward from the root cause.

[0092] After crossing the obstacle, under the action of the weight of the seat and the user, the rear support rod 521 is pressed down to restore the seat to its original position, and the seat still remains horizontal during the reset process. At the same time, a spring can be arranged between the rear support rod 521 and the balance chute 523 to play a buffering role during the falling process of the seat, improving the comfort of the seat before and after crossing the obstacle.

[0093] In the present invention, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance; the term "plural" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "connected", "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "connected" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0094] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation, and therefore cannot be construed as a limitation of the present invention.

[0095] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0096] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0097] In view of the foregoing detailed description, these and other changes may be made to these embodiments. This written description discloses the present invention including the best mode of the embodiments. The scope of the patent obtained by the present invention is defined by the claims, and the claims are not limited by the present disclosure. The protection scope of the present invention is not limited thereto. Any person skilled in the art within the scope disclosed by the present invention, according to the technical solution and concept of the present invention, makes equivalent replacements or changes, and all are within the protection scope of the present invention.

Claims

1. An obstacle-crossing wheelchair, comprising a wheelchair main body (1), the wheelchair main body (1) including a frame and a seat, wheels being arranged on the left and right sides of the frame, characterized in that, It also includes a driving mechanism (2) and an obstacle-crossing mechanism (3); The driving mechanism (2) is symmetrically arranged on the left and right sides of the frame and is connected to the wheels. The driving mechanism (2) can drive the wheels to rotate and move forward; The obstacle-crossing mechanism (3) includes an internally meshing step wheel assembly (31), an obstacle-crossing wheel (32), and a lower pair mechanism (33). The internally meshing step wheel assembly (31) is connected to the wheels. The internally meshing step wheel assembly (31) includes an externally meshing gear (311) and an internally meshing gear (312). The obstacle-crossing wheel (32) is located on the front side of the advancing direction of the wheels; The driving mechanism (2) drives the wheels and the externally meshing gear (311) to rotate. The externally meshing gear (311) drives the internally meshing gear (312) to rotate and cooperates with the lower pair mechanism (33) to drive the obstacle-crossing wheel (32) to perform a rotary motion; so that the obstacle-crossing wheel (32) can abut against the top surface of the protruding obstacle to serve as a fulcrum to assist the wheels in crossing the obstacle; The driving mechanism (2) includes a ratchet mechanism (21) and a pawl mechanism (22) that are meshed unidirectionally. The ratchet mechanism (21) can rotate unidirectionally. The ratchet mechanism (21) and the pawl mechanism (22) cooperate to drive the wheels to rotate; A wheel main shaft (11) is connected to the axial center position of the wheels and the axial center position of the pawl mechanism (22). The pawl mechanism (22) includes a pawl rotating shaft (221), a pawl support (222), a torsion spring (223), and a pawl member (224); The ratchet mechanism (21) includes a ratchet handle (211). The tooth groove of the ratchet handle (211) is meshed unidirectionally with the pawl member (224). The ratchet handle (211) swings back and forth to cooperate with the pawl member (224) to drive the wheels to rotate unidirectionally; The motion trajectory of the rotary motion of the obstacle-crossing wheel (32) is an ellipse and is the same as the rotation direction of the wheels. The obstacle-crossing wheel (32) is always located on the front side of the advancing direction of the wheels. The horizontal height of the bottom of the obstacle-crossing wheel (32) is always higher than the horizontal height of the bottom of the wheels; The lower pair mechanism (33) includes a frame rod (331), a rocker (332), a connecting rod (333), and a crank (334). The frame rod (331), the crank (334), the connecting rod (333), and the rocker (332) are sequentially connected end to end in a rotating manner; The frame rod (331) is connected to the internally meshing gear (312) and fixes the relative positions of the externally meshing gear (311) and the internally meshing gear (312). One end of the frame rod (331) is connected to the internally meshing gear (312); One end of the crank (334) is connected to the internally meshing gear (312). The crank (334) rotates synchronously under the drive of the internally meshing gear (312). The other end of the crank (334) is rotatably connected to the connecting rod (333); The obstacle-crossing wheel (32) is arranged on the connecting rod (333). The other end of the connecting rod (333) is rotatably connected to the rocker (332).

2. The obstacle-crossing wheelchair according to claim 1, wherein The wheel spindle (11) is connected to the external gear (311), and the external gear (311) rotates under the drive of the drive mechanism (2).

3. The obstacle-crossing wheelchair according to claim 1 or 2, characterized in that, It further includes a center-of-gravity adjustment mechanism (5) and an auxiliary wheel (4). The center-of-gravity adjustment mechanism (5) includes a lifting mechanism (51) and a balancing mechanism (52), and the auxiliary wheel (4) is arranged below the balancing mechanism (52); During the obstacle-crossing process of the wheelchair main body (1), the lifting mechanism (51) lifts and supports the front end of the seat, and the balancing mechanism (52) supports the rear end of the seat under the drive of the lifting mechanism (51). The seat is vertically lifted and maintained in a horizontal state under the support of the lifting mechanism (51) and the balancing mechanism (52); After the wheelchair main body (1) crosses the obstacle, the lifting mechanism (51) and the balancing mechanism (52) return to their original positions, and the seat vertically descends and maintains a horizontal state.

4. The obstacle-crossing wheelchair according to claim 3, wherein the lifting mechanism (51) includes a front support rod (511), a first pulley (512), a lifting chute (513), and a lifting support rod (514); the lifting chute (513) is horizontally arranged. One end of the front support rod (511) is connected to the bottom of the front end of the seat, and the other end of the front support rod (511) is connected to the first pulley (512). The first pulley (512) can horizontally slide in the lifting chute (513). Both ends of the lifting support rod (514) are respectively rotatably connected to the first pulley (512) and the auxiliary wheel (4).

5. The obstacle-crossing wheelchair according to claim 4, wherein the balancing mechanism (52) includes a rear support rod (521), a second pulley (522), a balancing chute (523), and a third pulley (524); the balancing chute (523) is vertically arranged. The rear support rod (521) slides up and down in the balancing chute (523). One end of the rear support rod (521) is connected to the second pulley (522), and the second pulley (522) abuts against the bottom of the rear end of the seat. The other end of the rear support rod (521) is connected to the third pulley (524) in the balancing chute (523).

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