wheelchair mobility aids

Abstract

This invention provides a wheelchair mobility assistance device, comprising: a rear unit having an axle orthogonal to the axle direction of the main wheel and a rear auxiliary wheel supporting the main wheel; a front unit having the aforementioned axle and a front auxiliary wheel supporting the front wheel; a switching lever for switching between a first state and a second state, the first state being a wheel assembly consisting of the main wheel and the front wheel on the ground, and the second state being a wheel assembly consisting of the rear auxiliary wheel and the front auxiliary wheel on the ground; and a connecting rod for transmitting the force applied to the switching lever between the rear unit and the front unit, the rear unit having a drive force transmission mechanism that contacts the main wheel in the second state and transmits the drive force applied to the main wheel to the rear auxiliary wheel.

Description

Technical Field

[0001] This invention relates to wheelchair mobility aids, such as wheelchair mobility aids that increase the degree of freedom of movement of a wheelchair. Background Technology

[0002] Wheelchairs have the characteristic of being difficult to move laterally over short distances or in confined spaces. Therefore, Japanese Patent Application Publication No. 2004-275528 discloses a technology for moving a wheelchair in any direction.

[0003] The wheelchair assistive device disclosed in Japanese Patent Application Publication No. 2004-275528 is a wheelchair assistive device mounted on a wheelchair having large wheels and assistive wheels capable of turning in all directions. It is configured to include an assistive wheel support member that supports a second assistive wheel at its lower end, a guide member fixed to the frame of the wheelchair and supporting the assistive wheel support member so that it can move in the vertical direction, a rod that engages with the assistive wheel support member at the middle part, and a linkage mechanism that connects one end of the rod to the frame of the wheelchair.

[0004] However, in the technology described in Japanese Patent Application Publication No. 2004-275528, lateral movement cannot be achieved by operating the main wheels; the passenger must move according to, for example, a transmission-based walking technique. That is, in the technology described in Japanese Patent Application Publication No. 2004-275528, there is a problem that in order to move laterally, the passenger must use a posture different from the normal movement based on the main wheels. Summary of the Invention

[0005] The present invention was made to solve this problem, and its purpose is to provide a wheelchair that allows the rider to move laterally using the same techniques as those used for movement based on the main wheels.

[0006] One embodiment of the wheelchair mobility assistance device of the present invention is a wheelchair mobility assistance device mounted on a wheelchair having a pair of main wheels and a pair of front wheels. The pair of main wheels are located on the backrest side of the frame, and the pair of front wheels are located on the foot side of the frame. The wheelchair mobility assistance device comprises: a rear unit located on the side of the pair of main wheels, having an axle in a direction orthogonal to the axle direction of the main wheels, and having rear auxiliary wheels for supporting the main wheels; and a front unit located on the side of the pair of front wheels, having an axle in a direction orthogonal to the axle direction of the main wheels, and having rear auxiliary wheels for supporting the front wheels. The rear unit includes a front auxiliary wheel for support; a switching lever for switching between a first state and a second state, wherein the first state is a normal wheel assembly consisting of the main wheel and the front wheel on the ground, and the second state is an auxiliary wheel assembly consisting of the rear auxiliary wheel and the front auxiliary wheel on the ground; and a connecting rod for transmitting the force applied to the switching lever between the rear unit and the front unit, wherein the rear unit has a drive force transmission mechanism that contacts the main wheel in the second state and transmits the drive force applied to the main wheel to the rear auxiliary wheel.

[0007] In the wheelchair mobility aid device of the present invention, a driving force is applied to the rear auxiliary wheel by means of the rear auxiliary wheel and the front auxiliary wheel, which have the lateral rolling direction of the wheelchair, while the main wheel and the front wheel are levitated.

[0008] According to the present invention, the wheelchair mobility aid device of the present invention provides a wheelchair that can be moved laterally by an operator using the same technique as movement based on the main wheels. Attached Figure Description

[0009] The features, advantages, technical and industrial significance of embodiments of the present invention are described below with reference to the accompanying drawings, wherein the same numbers denote the same elements.

[0010] Figure 1 This is a schematic diagram of a wheelchair equipped with the wheelchair mobility aid device of Embodiment 1.

[0011] Figure 2 This is a schematic diagram of the wheelchair mobility aid device according to Embodiment 1.

[0012] Figure 3 This is a diagram illustrating the front unit of the wheelchair mobility aid device according to Embodiment 1.

[0013] Figure 4 This is a diagram illustrating the rear unit of the wheelchair mobility aid device according to Embodiment 1.

[0014] Figure 5 This is a diagram illustrating the driving force transmission mechanism of the rear unit in Embodiment 1.

[0015] Figure 6 This is a diagram illustrating the first state of the wheelchair mobility aid device according to Embodiment 1.

[0016] Figure 7 This diagram illustrates the intermediate state of the wheelchair mobility assistance device in Embodiment 1 as it transitions from the first state to the second state.

[0017] Figure 8 This is a diagram illustrating the second state of the wheelchair mobility aid device according to Embodiment 1. Detailed Implementation

[0018] Implementation Method 1

[0019] first, Figure 1 A schematic diagram of a wheelchair 1 equipped with the wheelchair mobility aid device of Embodiment 1 is shown. In the following description, the direction of the chest side of the body of the occupant seated in the wheelchair 1 is defined as the forward direction, the direction of the back side of the occupant is defined as the rear direction, and the direction orthogonal to the direction from the rear to the front is defined as the lateral direction.

[0020] like Figure 1 As shown, the wheelchair 1 of Embodiment 1 is a push-type wheelchair with a wheelchair mobility aid 20 installed. A footrest 11 is installed at the foot side end of the frame 10, and a handle 12 for assisting the user in operating the wheelchair 1 is installed at the end of the frame 10 opposite to the footrest 11. Furthermore, armrests 13 for the user to rest their hands, a seat 14 for the user to contact when seated, and a backrest 15 are installed on the frame 10.

[0021] Furthermore, in wheelchair 1, a pair of main wheels 16 are provided on the backrest 15 side of the frame, and a pair of front wheels 17 are provided on the footrest 11 side of the frame 10. The main wheels 16 are equipped with push-pull components that allow the occupant to rotate them. The main wheels 16 rotate in one direction around an axle extending in the opposite direction of the pair of main wheels 16. The front wheels 17 are mounted on the frame 10 in a manner that allows them to rotate in all directions.

[0022] Furthermore, in wheelchair 1, a wheelchair mobility aid 20 is mounted on the frame 10 below the main wheels 16. The wheelchair mobility aid 20 changes the wheelchair 1 from a first state where the main wheels 16 and front wheels 17 are in contact with the floor to a second state where the main wheels 16 and front wheels 17 are off the floor by tilting the switching lever 31 forward (e.g., towards the feet). In the second state, the front and rear auxiliary wheels of the wheelchair mobility aid 20 are in contact with the ground, and the force generated by rotating the main wheels 16 is transmitted to the rear auxiliary wheels, thereby causing the wheelchair 1 to move laterally. Therefore, the wheelchair mobility aid 20 will be described in detail below.

[0023] Figure 2 A schematic diagram of the wheelchair mobility assistance device 20 according to Embodiment 1 is shown. Figure 3 The figure shows the front unit 30 of the wheelchair mobility aid device according to Embodiment 1. Figure 4 The diagram shows the rear unit of the wheelchair mobility aid according to Embodiment 1.

[0024] like Figure 2 As shown, the wheelchair mobility aid 20 has a front unit 30, a rear unit 40, and a connecting rod 50. The connecting rod 50 is used to transmit the force applied to the switching lever 31 between the front unit 30 and the rear unit 40.

[0025] The switching lever 31 is an operating lever used to switch between a first state and a second state. The first state is the state in which the normal wheel set consisting of the main wheel 16 and the front wheel 17 is on the ground, and the second state is the state in which the auxiliary wheel set consisting of the rear auxiliary wheel 43c and the front auxiliary wheel 37 is on the ground.

[0026] The front unit 30 is located on the side of a pair of front wheels, has an axle in a direction orthogonal to the axle direction of the main wheel 16, and has front auxiliary wheels 37 that support the front wheels 17. Furthermore, in the wheelchair mobility aid 20 of Embodiment 1, the switching lever 31 is configured to be connected to the front unit 30; however, the switching lever 31 can also be located further rearward than the front wheels 17. However, by placing the switching lever 31 near the front wheels 17, it facilitates the operation of switching the wheelchair 1's driving mode from the first state to the second state; therefore, it is preferable that the switching lever 31 be located near the front wheels 17.

[0027] Furthermore, the rear unit 40 is located on the side of a pair of main wheels, has an axle in a direction orthogonal to the axle direction of the main wheels 16, and has a rear auxiliary wheel 43c that supports the main wheels 16. The rear unit 40 also has a drive force transmission mechanism 43, which, in the second state, contacts the main wheels 16 and transmits the drive force applied to the main wheels 16 to the rear auxiliary wheel 43c.

[0028] Next, refer to Figure 2 as well as Figure 3 The structure of the front unit 30 will be described in detail below. The front unit 30 is assembled on a chassis 39 with a switching lever 31, a frame mounting part 32, a mode switching shaft 33, a cam plate 34, a cam follower 35, a connecting rod plate 36, and a front auxiliary wheel 37. The switching lever 31 mounts the rotation shaft to the mode switching shaft 33 of the front unit 30. The frame mounting part 32 is a structure for mounting the front unit 30 to the frame 10.

[0029] Switching levers 31 are installed at both ends of the mode switching shaft 33, forming the rotation axis of the switching levers 31. Rotation is achieved by operating the switching levers 31. Figure 2 as well as Figure 3 In the example shown, two connecting rod plates 36 are mounted on the portion of the mode switching shaft 33 that is clamped by the switching lever 31. It should be noted that the connecting rod plate 36 can also be a single piece, but in this case, further work is needed on the subsequent construction of the connecting rod plate 36. One end of the connecting rod plate 36 is connected to the mode switching shaft, and the other end is connected to the connecting rod 50. The connecting rod plate 36 rotates in response to the movement of the switching lever 31, causing the connecting rod to move back and forth in a direction orthogonal to the axle direction of the main wheel 16.

[0030] Furthermore, in Figure 2 as well as Figure 3 In the example shown, a cam plate 34 is provided near the center of the extension direction of the mode switching shaft 33 and is clamped by the connecting rod plate 36. A cam follower 35 is provided in contact with the cam plate 34. The cam follower 35 is mounted on a cam follower base 35a. The cam follower base 35a is connected to the front auxiliary wheel 37 via a shaft passing through the chassis 39. The shaft connecting the cam follower base 35a and the front auxiliary wheel 37 is arranged to pass through a spring 38. The spring 38 is a compression spring that lifts the front auxiliary wheel 37 toward the chassis 39 when the cam follower 35 rises in response to the movement of the cam plate 34. That is, the spring 38 is a front elastic member that maintains the front auxiliary wheel 37 in a non-grounded state in the first state.

[0031] Reference Figure 2 as well as Figure 4 The structure of the rear unit 40 will be described below. The rear unit 40 is assembled on a chassis 44 with a frame mounting part 41, a linkage mechanism 42, a drive force transmission mechanism 43, a chassis 44, and a spring 45. The frame mounting part 41 is configured to mount the rear unit 40 to the frame 10. The linkage mechanism 42 presses the rear auxiliary wheel, which is connected to the drive force transmission mechanism 43, against the floor in response to the movement of the connecting rod 50. The linkage mechanism 42 has an upper linkage arm and a lower linkage arm, and the connecting rod 50 is connected at the point where the upper linkage arm and the lower linkage arm are connected. Furthermore, the end of the upper linkage arm is connected to the upper linkage arm mounting part 46 of the chassis 44, and the end of the lower linkage arm is connected to the lower linkage arm mounting part 47 of the drive force transmission mechanism 43. The upper linkage arm mounting part 46 and the lower linkage arm mounting part 47 are aligned along... Figure 4 The components are assembled to each mounting part in a manner that allows rotation in the direction of the paper (e.g., about the rotation axis extending in the front-rear direction of the wheelchair 1). Furthermore, the linkage mechanism 42 presses the drive force transmission mechanism 43 onto the floor surface by increasing the opening angle of the upper and lower linkage arms from the connecting rod 50 according to the pressing force.

[0032] The drive force transmission mechanism 43 is rotatably mounted on the chassis 44 relative to the rear unit 40. Furthermore, the drive force transmission mechanism 43 is connected to the chassis 44 via a spring 45. The spring 45 is a compression spring that applies an auxiliary force to the drive force transmission mechanism 43 when pulling it down towards the chassis 44, and maintains the drive force transmission mechanism 43 in a raised position towards the chassis 44. In other words, the spring 45 is a rear elastic component that keeps the rear auxiliary wheel 43c mounted on the drive force transmission mechanism 43 in a non-grounded state in the first state.

[0033] In the second state, the drive force transmission mechanism 43 contacts the main wheel, transmitting the driving force applied to the main wheel to the rear auxiliary wheel. The drive force transmission mechanism 43 is assembled with the drive shaft 43a and the rear auxiliary wheel 43c on the gearbox 43b. Figure 5 The diagram illustrates the drive force transmission mechanism of the rear unit in Embodiment 1. Figure 5 As shown, the rotation axis AXa of the drive shaft 43a and the rotation axis AXb of the rear auxiliary wheel 43c are arranged orthogonally to each other. Furthermore, the gearbox 43b includes a helical gear 48 having the same rotation axis as the drive shaft 43a and a helical gear 49 having the same rotation axis as the rear auxiliary wheel 43c. The gearbox 43b transmits the driving force transmitted by the drive shaft 43a when it is in contact with the main wheel 16 as a lateral driving force to the rear auxiliary wheel 43c via the helical gears 48 and 49.

[0034] Next, the operation of the wheelchair mobility assistance device 20 will be explained. The wheelchair mobility assistance device 20 switches between a first state and a second state by the user operating the switching lever 31. The first state is when the normal wheel assembly, consisting of the main wheel 16 and the front wheel 17, is on the ground. The second state is when the auxiliary wheel assembly, consisting of the rear auxiliary wheel 43c and the front auxiliary wheel 37, is on the ground. It should be noted that in both the first and second states, the wheel not on the ground is in a state of being lifted off the floor. (Refer to the following...) Figures 6-8 For each state, describe the state of the wheelchair mobility aid 20. Figures 6-8 The upper section shows a diagram illustrating the state of the front unit 30, the middle section shows the state of the rear unit 40 from a side view (e.g., from a lateral view), and the lower section shows the state of the rear unit 40 as viewed from the rear of the wheelchair 1.

[0035] Figure 6 This diagram illustrates the first state of the wheelchair mobility aid device according to Embodiment 1. Figure 6As shown, in the first state, the switching lever 31 is in its most upright position. Furthermore, when the switching lever 31 is in this upright position, the side of the cam plate 34 with the shorter distance from the center to the edge of the mode switching shaft 33 contacts the cam follower 35. Also, when the cam follower 35 is in a position close to the mode switching shaft 33, the cam follower base 35a is maintained at its highest position by the spring 38. Therefore, the front auxiliary wheel 37 is maintained at a distance G1 from the floor surface.

[0036] And, as Figure 6 As shown, in the first state, the rear auxiliary wheel 43c in the rear unit 40 is also maintained at a distance G1 from the floor surface. In this first state, the connecting rod 50 is in its forwardmost position, and the angle formed by the upper connecting arm 42a and the lower connecting arm 42b of the linkage mechanism 42 is at its narrowest. Furthermore, in this state of the linkage mechanism 42, the linkage mechanism 42 raises the drive force transmission mechanism 43 upward. Moreover, the raising of the drive force transmission mechanism 43 is also achieved by the spring 45, which maintains a state of pulling the drive force transmission mechanism 43 upward. In addition, in the first state, the drive shaft 43a is maintained in a position where it is not in contact with the main wheel 16.

[0037] Figure 7 This diagram illustrates the intermediate states of the wheelchair mobility assistance device in Embodiment 1 during its transition from the first state to the second state. (See diagram below.) Figure 7 As shown, in the mid-switching state, compared to the first state, the switching lever 31 is in a state tilted towards the ground. In this state, corresponding to the rotation of the mode switching shaft 33, the cam plate 34 tilts, and the distance between the mode switching shaft 33 and the cam follower 35 increases. As a result, the cam follower base 35a is pressed down towards the floor, and the front auxiliary wheel 37 touches the ground. At this time, in the mid-switching state, both the front wheel 17 and the front auxiliary wheel 37 are in a state of contact with the ground.

[0038] And, as Figure 7 As shown, in the mid-switching state, the rear auxiliary wheel 43c in the rear unit 40 also approaches the floor surface, and the rear auxiliary wheel 43c contacts the floor surface. In this mid-switching state, the connecting rod 50 is in a more rearward position than in the first state, and the angle formed by the upper connecting arm 42a and the lower connecting arm 42b of the linkage mechanism 42 is wider than in the first state. Furthermore, in this state of the linkage mechanism 42, the linkage mechanism 42 presses the drive force transmission mechanism 43 lower towards the floor than in the first state. Furthermore, the drive force transmission mechanism 43 undergoes a transformation that opens outward from the vehicle body, centered on the part that is rotatably mounted on the chassis. Furthermore, the rear auxiliary wheel 43c rotates and moves outward from the vehicle body after touching the ground.

[0039] Figure 8This diagram illustrates the second state of the wheelchair mobility aid device according to Embodiment 1. (As shown...) Figure 8 As shown, in the second state, the switching lever 31 is further lowered towards the feet compared to the mid-switching state. In this state, corresponding to the rotation of the mode switching shaft 33, the cam plate 34 tilts, maintaining a position where the distance between the mode switching shaft 33 and the cam follower 35 is greater than in the first state. Thus, the cam follower base 35a is pressed down towards the floor, and the front auxiliary wheel 37 touches the ground. At this time, in the second state, the front wheel 17 is in a non-grounded state by maintaining a distance G2 relative to the floor surface.

[0040] And, as Figure 8 As shown, in the second state, the rear auxiliary wheel 43c in the rear unit 40 is also in contact with the floor surface, while the main wheel 16 is not in contact with the floor surface at a distance of G2. In this second state, the connecting rod 50 is in its rearmost position, and the angle formed by the upper connecting arm 42a and the lower connecting arm 42b of the linkage mechanism 42 becomes the largest. Figure 8 In the example shown, in the second state, the angle formed by the upper link arm 42a and the lower link arm 42b is approximately 180 degrees. Furthermore, in this state of the linkage mechanism 42, the linkage mechanism 42 lowers the drive force transmission mechanism 43 to the floor side. The drive force transmission mechanism 43 remains in a state where it has undergone a transformation that opens outwards from the vehicle body, centered on a portion rotatably mounted on the chassis. In this second state, the drive shaft 43a is in contact with the main wheel 16 and can receive the driving force applied to the main wheel 16.

[0041] According to the above description, in the first state, the wheelchair mobility assist device 20 of Embodiment 1 allows the wheelchair 1 to be operated as if it were not in use by levitizing the front auxiliary wheels 37 and the drive shaft 43a from the floor. On the other hand, in the second state, the wheelchair mobility assist device 20 of Embodiment 1 levits the main wheels 16 and the front wheels 17 from the floor, while the front auxiliary wheels 37 and the rear auxiliary wheels 43c are in contact with the floor. Furthermore, the rotation axes of the front auxiliary wheels 37 and the drive shaft 43a are orthogonal to the rotation axis of the main wheels 16. In the second state, the wheelchair mobility assist device 20 transmits the driving force applied by the occupant to the main wheels 16 to the rear auxiliary wheels 43c via the drive shaft 43a. Therefore, the wheelchair mobility assist device 20 of Embodiment 1 allows the wheelchair 1 to be easily moved laterally without the occupant changing their posture.

[0042] Furthermore, in the wheelchair mobility aid 20 of Embodiment 1, the transition from the first state to the second state is achieved by folding the switching lever 31 forward, centered on the position of the front wheel 17 side of the wheelchair 1. As a result, when the occupant folds the switching lever 31 forward, their buttocks are raised off the seat 14, and their center of gravity shifts towards the footrest 11. This reduces the load applied to the main wheels 16 and the force exerted by the occupant on the switching lever 31 to raise the wheelchair 1. In other words, by placing the switching lever 31 under the feet and folding it forward, the transition from the first state to the second state is achieved, enabling a smooth state-switching operation.

[0043] Furthermore, in the wheelchair mobility aid 20 of Embodiment 1, the switching operation is performed using only the force applied to the switching lever 31, and in the second state, lateral movement can be achieved using the rotational force applied to the main wheels 16. That is, by using the wheelchair mobility aid 20, lateral movement is possible without using motor components such as an electric motor. Moreover, since no motor component is required, the risk of malfunction is reduced, and maintenance such as parts replacement becomes easier.

[0044] The invention made by the inventors has been specifically described above based on the embodiments. However, the invention is not limited to the embodiments described above, and various modifications can be made without departing from its spirit.

Claims

1. A wheelchair mobility aid, fitted to a wheelchair having a pair of main wheels and a pair of front wheels, the pair of main wheels being located on the backrest side of the frame, and the pair of front wheels being located on the foot side of the frame, wherein, The wheelchair mobility aid has the following features: The rear unit is located on the side of the pair of main wheels, has an axle in a direction orthogonal to the axle direction of the main wheels, and has a rear auxiliary wheel that supports the main wheels. The front unit is located on the side of the pair of front wheels, has an axle in a direction orthogonal to the axle direction of the main wheel, and has a front auxiliary wheel that supports the front wheels; The switching lever switches between a first state and a second state. The first state is when the normal wheel assembly, consisting of the main wheel and the front wheel, is on the ground, and the second state is when the auxiliary wheel assembly, consisting of the rear auxiliary wheel and the front auxiliary wheel, is on the ground. as well as A connecting rod transmits the force applied to the switching lever between the rear unit and the front unit. The rear unit has a drive force transmission mechanism, which contacts the main wheel in the second state and transmits the driving force applied to the main wheel to the rear auxiliary wheel. The switching lever has a rotation center axis on the side of the frame near the front wheel, and accepts an operation of folding it down towards the feet to switch the rear unit and the front unit from the first state to the second state. The front unit has: The mode switching axis is connected to the switching lever and rotates in response to the movement of the switching lever; A cam plate, connected to the mode switching shaft; and The connecting rod plate has one end connected to the mode switching shaft and the other end connected to the connecting rod. Corresponding to the movement of the switching rod, the connecting rod moves back and forth in a direction orthogonal to the axle direction of the main wheel. The front unit is configured to press the front auxiliary wheel against the floor in response to the action of the cam plate. The rear unit has a linkage mechanism that, in response to the movement of the connecting rod, presses the rear auxiliary wheel, which is connected to the drive force transmission mechanism, against the floor. The drive force transmission mechanism is rotatably mounted on the chassis relative to the chassis of the rear unit. In the second state, the drive force transmission mechanism is maintained in a state in which it has undergone a transformation that opens outward from the vehicle body with the part rotatably mounted on the chassis as the center.

2. The wheelchair mobility aid according to claim 1, wherein, The rear unit has a rear elastic component, which maintains the rear auxiliary wheel in a non-grounded state in the first state. The front unit has a front elastic component that maintains the front auxiliary wheel in a non-grounded state in the first state.

3. The wheelchair mobility aid according to claim 1 or 2, wherein, The driving force transmission mechanism has: The drive shaft, in the second state, is in contact with the main wheel; and The helical gear converts the driving force transmitted to the drive shaft into the rotational force of the rear auxiliary wheel.

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