JP2022062712A - wheelchair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheelchair facilitating travel operation and capable of reducing a rollover risk.

SOLUTION: A wheelchair comprises a pair of main wheels, a seat part provided between the pair of main wheels, and an auxiliary wheel provided at the rear of the seat part. Each main wheel has a tire including a plurality of small tires rotating in the orthogonal direction of the circumferential direction, disposed along the circumference. An interval of the pair of main wheels becomes narrower towards the front of the seat part.

SELECTED DRAWING: Figure 5

COPYRIGHT: (C)2022,JPO&INPIT

Description

The present invention relates to a wheelchair.

Conventionally, as a wheelchair for competition, a body frame, a cage, a pair of left and right main wheels, a front fork, a main handle, front wheels and a track lever are provided, the left and right main wheels are arranged on both sides of the cage, and the body frame is a cage. The front fork is steerable at the front end of the body frame, the front wheels are supported at the lower end of the front fork, the main handlebar is attached to the upper end of the front fork, and the track lever is It is known that the steering angle of the front wheels is set, an elbow rest extending in the vehicle width direction is provided on the vehicle body frame, and the elbow rest is provided in the vicinity of the track lever (see Patent Document 1).

Further, as a wheelchair tire, it is known that by providing a plurality of small rubber tires that can rotate in a direction perpendicular to the wheel, it is possible to move in the left-right direction in addition to the movement in the front-rear direction. (See Patent Document 2).

JP-A-2019-063017 Design Registration No. 1566142 Gazette

However, the conventional wheelchair requires skill in running operation, and there is a risk that the wheelchair rolls over during running.

An object of the present invention is to provide a wheelchair that is easy to operate and can reduce the risk of rollover.

The wheelchair according to the present invention includes a pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided behind the seat portion, and the main wheels are provided in the circumferential direction. A wheelchair having a plurality of small tires rotating in the orthogonal direction of the wheelchair having tires arranged along the circumference, and the distance between the pair of main wheels becomes narrower toward the front of the seat portion. It is characterized by.

The wheelchair according to the present invention includes a pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided in front of the seat portion, and the main wheels are provided in the circumferential direction. A wheelchair having a plurality of small tires rotating in the orthogonal direction of the wheelchair having tires arranged along the circumference, and the distance between the pair of main wheels becomes narrower toward the front of the seat portion. It is characterized by.

In the above-mentioned wheelchair, the vertical propulsion force or the vertical propulsion force of the wheelchair is based on a graph showing the relationship between the inclination angle of the pair of main wheels with respect to the traveling direction of the wheelchair and the vertical propulsion force or the lateral propulsion force of the wheelchair. It is desirable that the inclination angle of the pair of main wheels is determined so that the lateral propulsion force becomes a predetermined propulsion force.

As described above, according to the present invention, a pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided behind the seat portion are provided, and the main wheels have a circumference. In a wheelchair with tires in which multiple small tires rotating in orthogonal directions are arranged along the circumference, the distance between the pair of main wheels becomes narrower toward the front of the seat. It is possible to provide a wheelchair that is easy to drive and can reduce the risk of rolling over.

Further, according to the present invention, a pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided in front of the seat portion are provided, and the main wheels are provided in the circumferential direction. In a wheelchair having tires in which a plurality of small tires rotating in the orthogonal direction are arranged along the circumference, the distance between the pair of main wheels becomes narrower as it goes to the front of the seat, so that the driving operation is performed. It is easy to provide a wheelchair that can reduce the risk of rolling over.

FIG. 1 is a diagram (No. 1) showing a wheelchair according to the first embodiment of the present invention. FIG. 2 is a diagram (No. 2) showing a wheelchair according to the first embodiment of the present invention. FIG. 3 is a diagram (No. 3) showing a wheelchair according to the first embodiment of the present invention. FIG. 4 is a diagram (No. 4) showing a wheelchair according to the first embodiment of the present invention. FIG. 5 is a diagram showing a positional relationship between a main wheel, an auxiliary wheel, and a seat portion in a wheelchair according to the first embodiment of the present invention. FIG. 6 is a graph showing the relationship between the angle θ1 and the vertical propulsion force and the lateral propulsion force in the wheelchair according to the first embodiment of the present invention. FIG. 7 is a diagram (No. 1) showing a wheelchair according to the second embodiment of the present invention. FIG. 7 is a diagram (No. 2) showing a wheelchair according to the second embodiment of the present invention. FIG. 9 is a diagram (No. 3) showing a wheelchair according to the second embodiment of the present invention. FIG. 10 is a diagram showing the positional relationship between the main wheel, the auxiliary wheel, and the seat portion in the wheelchair according to the second embodiment of the present invention. FIG. 11 is a graph showing the relationship between the angle θ2 and the vertical propulsion force and the vertical propulsion force in the wheelchair according to the second embodiment of the present invention.

[First Embodiment]
The wheelchair according to the first embodiment of the present invention will be described with reference to FIGS. 1 to 5.

(Overall structure of wheelchair)
The entire structure of the wheelchair of the present embodiment will be described with reference to FIGS. 1 and 2. 1 (a) is a perspective view of the wheelchair of the present embodiment as viewed from the front, FIG. 1 (b) is a perspective view of the wheelchair of the present embodiment as viewed from the back, and FIG. 2 (a) is the present embodiment. 2A is a front view of the wheelchair of the embodiment, FIG. 2B is a right side view of the wheelchair of the present embodiment, and FIG. 2C is a top view of the wheelchair of the present embodiment.

In the wheelchair 10, a pair of left and right main wheels 14 and 16, auxiliary wheels 18, and a seat portion 20 are attached to a vehicle body frame 12 for supporting the entire structure of the wheelchair.

In the wheelchair 10 of the present embodiment, the pair of left and right main wheels 14 and 16 are located on the traveling direction side of the wheelchair 10, that is, in front of the seat portion 20, and on the side opposite to the traveling direction of the wheelchair 10, that is, behind the seat portion 20. It is a so-called front two-wheel type wheelchair 10 in which the auxiliary wheel 18 is located.

The vehicle body frame 12 has a pair of left and right main frames 12a and 12b. The pair of left and right main frames 12a and 12b are connected by a coupling frame 12c at an intermediate position thereof. The main frames 12a and 12b and the connecting frame 12c form a solid triangular frame.

A main wheel 14 is rotatably attached to one end of the main frame 12a, and a main wheel 16 is rotatably attached to one end of the main frame 12b.

The main wheel 14 is composed of a circular tire 14a in contact with the ground and a circular hand rim 14b provided on the outside of the tire 14a. At the center of the main wheel 14, a rotating portion 14c rotatably connected to one end of the main frame 12a is provided. The hand rim 14b is fixed to the rotating portion 14c by the spokes 14d.

The main wheel 16 is composed of a circular tire 16a in contact with the ground and a circular hand rim 16b provided on the outside of the tire 16a. At the center of the main wheel 16, a rotating portion 16c rotatably connected to one end of the main frame 12a is provided. The hand rim 16b is fixed to the rotating portion 16c by the spokes 16d.

When the user grabs and turns the hand rims 14b and 16b, the tires 14a and 16a of the main wheels 14 and 16 are rotated to steer the wheelchair 10.

The pair of left and right main wheels 14 and 16 in the present embodiment are not parallel to each other as in a conventional wheelchair, but are attached to one end of the main frames 12a and 12b so that the distance between the main wheels 14 and 16 becomes narrower in the traveling direction of the wheelchair 10. There is.

The other end of the main frame 12a and the other end of the main frame 12b are coupled to rotatably support one auxiliary wheel 18.

The auxiliary wheels 18 are attached to the other ends of the main frames 12a and 12b so as to be parallel to the traveling direction of the wheelchair 10.

The pair of left and right main wheels 14, 16 and the auxiliary wheels 18 of the wheelchair 10 are rotatably attached to the vertices of a rigid triangular frame composed of the main frames 12a and 12b and the coupling frame 12c, respectively. The tires 14a and 16a of the main wheels 14 and 16 rotatably attached to the apex of the rigid triangular frame and the auxiliary wheels 18 come into contact with the ground to support the entire wheelchair 10.

A pair of left and right seat support frames 12d and 12e for supporting the seat 20 are coupled to a triangular frame composed of the main frames 12a and 12b and the coupling frame 12c. The seat support frames 12d and 12e have a U-shape, and their ends are connected to the main frames 12a and 12b, respectively. The seat portion 20 is fixed on the pair of left and right seat portion support frames 12d and 12e.

The seat portion 20 is composed of a seat surface portion 20a for supporting the buttocks of the user and a backrest portion 20b for supporting the back of the user. The seat surface portion 20a and the backrest portion 20b are curved inward so as to fit the buttocks and back of the user sitting on the seat portion 20.

(Detailed structure of tires for main wheels)
The detailed structure of the tires 14a and 16a of the main wheels 14 and 16 is shown in FIG. 3 (a) is a partially enlarged view of the tire, and FIG. 3 (b) is a sectional view taken along line AA of FIG. 3 (a).

The tires 14a and 16a of the main wheels 14 and 16 are arranged along the circumference with a large number of small rubber tires 22 which are small rotatable tires mounted in a direction orthogonal to the circumferential direction, for example, 56 tires. It is a tire for wheelchairs.

As shown in FIG. 3A, a small rubber tire 22 is provided via a bearing 24 over the entire circumference of the tires 14a and 16a of the main wheels 14 and 16.

As shown in FIG. 3B, the small rubber tire 22 is composed of a central rotating portion 26 and a tire rubber portion 28 provided around the rotating portion 26. The tire rubber portion 28 can rotate around the rotating portion 26 in either the right direction or the left direction in FIG. 3 (b).

Conventional wheelchair tires are basically for moving in the front-rear direction, but the tires 14a and 16a of the main wheels 14 and 16 of the present embodiment are composed of a large number of small rubber tires 22 over the entire circumference. Therefore, in addition to the movement in the front-rear direction with respect to the tires 14a and 16a, it is possible to move in the left-right direction by the plurality of small rubber tires 22.

As a result, the user can rotate the tires 14a and 16a of the main wheels 14 and 16 by grasping and turning the hand rims 14b and 16b of the main wheels 14 and 16, and the wheelchair 10 can be moved in each of the front, rear, left and right directions, and further. Can be moved diagonally.

Since the wheelchair of the present embodiment moves in all directions, the risk of falling due to a lateral force applied as in a conventional wheelchair can be significantly reduced.

Further, the wheelchair of the present embodiment can be finely operated by the user by operating the wheelchair, such as slightly dodging the opponent to the side, and can be expected to be used not only in the medical scene but also in the sports competition scene.

Further, since the wheelchair tire of the present embodiment is composed of a plurality of small rubber tires, it is possible to partially replace the tire in case of a tire defect due to a scratch or the like received from the road surface.

(Wheelchair operation by the user)
The state in which the user operates the wheelchair of the present embodiment will be described with reference to FIG. FIG. 4A is a diagram showing a situation of operation by the user from the traveling direction side of the wheelchair 10, and FIG. 4B is a diagram showing a situation of operation by the user from the opposite side of the wheelchair 10 in the traveling direction. It is a figure.

As shown in FIGS. 4A and 4B, the user grasps the hand rims 14b and 16b of the pair of main wheels 14 and 16 with his left and right hands and turns the main wheels 14 and 16 forward. The tires 14a and 16a can be rotated forward to advance the wheelchair 10 in the traveling direction.

Further, the user grasps the hand rims 14b and 16b of the pair of main wheels 14 and 16 with his left and right hands and turns them backward to rotate the tires 14a and 16a of the main wheels 14 and 16 backward and wheelchair. 10 can be set back.

Further, the user grasps the hand rims 14b and 16b of the main wheels 14 and 16 with his left and right hands, and rotates one of the hand rims 14b and 16b forward and does not rotate the other or rotates the wheelchair backward. The traveling direction of the 10 can be bent, and the wheelchair 10 can be rotated on the spot.

(Positional relationship between main wheel, auxiliary wheel and seat)
The positional relationship between the main wheels 14 and 16 and the auxiliary wheels 18 and the seat portion 20 in the wheelchair 10 of the present embodiment will be described with reference to FIG. FIG. 5 is a diagram showing the positional relationship between the main wheels 14 and 16, the auxiliary wheels 18, and the seat portion 20 when the wheelchair 10 is viewed from above.

When the center of the main wheels 14 and 16 and the center of the auxiliary wheel 18 are connected, the triangle of the alternate long and short dash line in FIG. 5 is formed. That is, the centers of the main wheels 14 and 16 and the centers of the auxiliary wheels 18 are located at each apex of the triangle of the alternate long and short dash line shown in FIG.

The pair of left and right main wheels 14 and 16 are not parallel to each other as in a conventional wheelchair, and are inclined inward by the same angle θ1 with respect to the traveling direction of the wheelchair 10, for example, as shown in FIG. As a result, the distance between the main wheels 14 and 16 becomes narrower toward the front of the seat portion 20.

The triangle connecting the centers of the main wheels 14 and 16 and the center of the auxiliary wheels 18 is an isosceles triangle. The height of this isosceles triangle is determined by the mounting position of the auxiliary wheel 18. How far the auxiliary wheel 18 is mounted from the main wheels 14 and 16 is determined in consideration of the stability of the wheelchair 10. The longer the distance between the main wheels 14 and 16 and the auxiliary wheels 18, the more stable the wheelchair 10 is.

The position of the center of gravity of the seat portion 20 is basically located inside the triangle of the alternate long and short dash line, and the entire seat portion 20 is substantially included in the triangle of the alternate long and short dash line. The seat portion 20 may be moved back and forth and left and right from the position shown in FIG. 5, but it is desirable that the position of the center of gravity thereof is at least located inside the triangle of the two-dot chain line. This ensures the stability of the wheelchair 10 when traveling. If the position of the center of gravity of the seat portion 20 deviates from the triangle of the two-dot chain line, the risk of the wheelchair 10 falling in the deviated direction increases.

(Angle of inclination of the main wheel)
As shown in FIG. 5, the pair of left and right main wheels 14 and 16 are tilted inward by an angle θ1 with respect to the traveling direction of the wheelchair 10. Since the main wheels 14 and 16 are tilted by an angle θ1 with respect to the traveling direction of the wheelchair 10, the force of the user rowing the main wheels 14 and 16 is the propulsive force in the forward direction of the wheelchair 10. It is distributed between the force and the lateral propulsion force, which is the lateral propulsion force of the wheelchair 10.

When the angle θ1 is 0 degrees (when the main wheels 14 and 16 are not tilted), all the force that the user rowed on the main wheels 14 and 16 becomes the vertical propulsion force (100%). However, if the angle θ1 is not 0 degrees, the vertical propulsion force and the lateral propulsion force are dispersed according to the angle θ1.

As a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ1, when the inclination angle θ1 of the pair of main wheels 14 and 16 is within the range of 10 to 45 degrees, forward propulsion is a problem. It was found that it was easy to secure the degree of freedom in the seating surface position.

Further, as a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ1, when the inclination angle θ1 of the pair of main wheels 14 and 16 is within the range of 45 degrees to 80 degrees, lateral propulsion is performed. Was performed without any problem, and it was found that it was easy to secure the degree of freedom in the seating surface position.

FIG. 6 is a graph showing the relationship between the angle θ1 and the vertical propulsion force and the lateral propulsion force.

For example, when the angle θ1 is 15 degrees, the vertical propulsion force is 96% of the vertical propulsion force when the angle θ1 is 0 degrees, and the lateral propulsion force is 90 degrees when the angle θ1 is 90 degrees. The lateral propulsion force of is 1 and becomes 25% of that. When the angle θ1 is 30 degrees, the vertical propulsion force is 87% and the lateral propulsion force is 50%. When the angle θ1 is 45 degrees, the vertical propulsion force is 70% and the lateral propulsion force is 70%.

As described above, when the angle θ1 becomes large, the vertical propulsive force becomes small, and the forward propulsive force of the wheelchair 10 becomes weak. However, when the angle θ1 becomes large, a lateral propulsive force is generated, so that the user can easily change the traveling direction of the wheelchair 10 by changing the operation balance of the left and right main wheels 14 and 16. The angle θ1 may be increased for a user who wants to easily move the wheelchair laterally, and the angle θ1 may be decreased for a user who wants to prioritize the forward movement of the wheelchair.

Therefore, according to the present embodiment, based on the graph of FIG. 6, the angle θ1 is determined so that the vertical propulsion force or the lateral propulsion force of the wheelchair becomes a predetermined propulsion force, and the body of the wheelchair user. Wheelchairs can be provided according to the situation and request.

As a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ1, the predetermined propulsive force with respect to the vertical propulsive force of the wheelchair is 50% of the predetermined propulsive force when the angle θ1 is 0 degrees. It is desirable that the angle is within the range of 90% (the angle θ1 is within the range of 60 to 25 degrees).

Further, as a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ1, the predetermined propulsive force with respect to the lateral propulsive force of the wheelchair is set to 1 when the angle θ1 is 90 degrees. It is desirable that the angle is within the range of 10% to 50% (the angle θ1 is within the range of 5 to 30 degrees).

Furthermore. As a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ1, it is desirable that the angle θ1 of the inclination of the pair of main wheels is within the range of 10 degrees to 45 degrees.

[Second Embodiment]
The wheelchair according to the second embodiment of the present invention will be described with reference to FIGS. 7 to 11.

(Overall structure of wheelchair)
The overall structure of the wheelchair of this embodiment will be described with reference to FIGS. 7 and 8. 7 (a) is a perspective view of the wheelchair of the present embodiment as viewed from the front, FIG. 7 (b) is a perspective view of the wheelchair of the present embodiment as viewed from the back, and FIG. 8 (a) is the present embodiment. 8 (b) is a front view of the wheelchair of the present embodiment, FIG. 8 (b) is a right side view of the wheelchair of the present embodiment, and FIG. 8 (c) is a top view of the wheelchair of the present embodiment.

In the wheelchair 30, a pair of left and right main wheels 34 and 36, auxiliary wheels 38, and a seat portion 40 are attached to a vehicle body frame 32 for supporting the entire structure of the wheelchair.

The wheels 14 and 16, the auxiliary wheels 18, and the seat portion 20 are attached. A pair of left and right main wheels 14 and 16 are located on the traveling direction side of the wheelchair 10, that is, in front of the seat 40, and an auxiliary wheel 18 is located on the opposite side of the wheelchair 10 in the traveling direction, that is, behind the seat 40.
The wheelchair 30 of the present embodiment is a so-called rear two-wheel type wheelchair 30 in which a pair of left and right main wheels 34 and 36 are located on the side opposite to the traveling direction of the wheelchair 30, and auxiliary wheels 38 are located in the traveling direction of the wheelchair 30. Is.

The vehicle body frame 32 has a pair of left and right main frames 32a and 32b. The pair of left and right main frames 32a and 32b are connected by a coupling frame 32c at an intermediate position thereof. The main frames 32a and 32b and the coupling frame 32c form a solid triangular frame.

A main wheel 34 is rotatably attached to one end of the main frame 32a, and a main wheel 36 is rotatably attached to one end of the main frame 32b.

The main wheel 34 is composed of a circular tire 34a in contact with the ground and a circular hand rim 34b provided on the outside of the tire 34a. At the center of the main wheel 34, a rotating portion 34c rotatably connected to one end of the main frame 32a is provided. The hand rim 34b is fixed to the rotating portion 34c by the spokes 34d.

The main wheel 36 is composed of a circular tire 36a in contact with the ground and a circular hand rim 36b provided on the outside of the tire 36a. At the center of the main wheel 36, a rotating portion 36c rotatably connected to one end of the main frame 32a is provided. The hand rim 36b is fixed to the rotating portion 36c by the spokes 36d.

The tires 34a and 36a of the main wheels 34 and 36 are a large number of small rotatable rubber tires 42 mounted in a direction orthogonal to the circumferential direction, for example, 56 tires for wheelchairs arranged along the circumference. be.

As shown in FIG. 8B, a small rubber tire 42 is provided via a bearing 44 over the entire circumference of the tires 34a and 36a of the main wheels 34 and 36.

When the user grabs and turns the hand rims 34b and 36b, the tires 34a and 36a of the main wheels 34 and 36 are rotated to steer the wheelchair 30.

The pair of left and right main wheels 34, 36 in the present embodiment are not parallel to each other as in a conventional wheelchair, but are attached to one end of the main frames 32a, 32b so that the distance becomes wider toward the traveling direction of the wheelchair 30. There is.

The other end of the main frame 32a and the other end of the main frame 32b are coupled to rotatably support one auxiliary wheel 38.

The auxiliary wheels 38 are attached to the other ends of the main frames 32a and 32b so as to be parallel to the traveling direction of the wheelchair 30.

The pair of left and right main wheels 34, 36 and the auxiliary wheels 38 of the wheelchair 30 are rotatably attached to the apex of a rigid triangular frame composed of the main frames 32a and 32b and the coupling frame 32c, respectively. The tires 34a, 36a of the main wheels 34, 36 rotatably attached to the apex of the rigid triangular frame and the auxiliary wheels 38 come into contact with the ground to support the entire wheelchair 30.

A pair of left and right seat support frames 32d and 32e for supporting the seat 40 are coupled to a triangular frame composed of the main frames 32a and 32b and the coupling frame 32c. The seat support frames 32d and 32e have a U-shape, and their ends are connected to the main frames 32a and 32b, respectively. The seat portion 40 is fixed on the pair of left and right seat portion support frames 32d and 32e.

The seat portion 40 is composed of a seat surface portion 40a for supporting the buttocks of the user and a backrest portion 40b for supporting the back of the user. The seat surface portion 40a and the backrest portion 40b are curved inward so as to fit the buttocks and back of the user sitting on the seat portion 40.

(Wheelchair operation by the user)
A state in which the user operates the wheelchair of the present embodiment will be described with reference to FIG. FIG. 9A is a diagram showing a situation of operation by the user from the traveling direction side of the wheelchair 30, and FIG. 9B is a diagram showing a situation of operation by the user from the opposite side of the wheelchair 30 in the traveling direction. It is a figure.

As shown in FIGS. 9A and 9B, the user grasps the hand rims 34b and 36b of the pair of main wheels 34 and 36 with his left and right hands and turns the main wheels 34 and 36 forward. The tires 34a and 36a can be rotated forward to advance the wheelchair 30 in the traveling direction.

Further, the user grasps the hand rims 34b and 36b of the pair of main wheels 34 and 36 with his left and right hands and turns them backward to rotate the tires 34a and 36a of the main wheels 34 and 36 backward and wheelchair. 30 can be retracted.

Further, the user grasps the hand rims 34b and 36b of the main wheels 34 and 36 with his left and right hands, and rotates one of the hand rims 34b and 36b forward and does not rotate the other or rotates the wheelchair backward. The traveling direction of the 30 can be bent, and the wheelchair 30 can be rotated on the spot.

(Positional relationship between main wheel, auxiliary wheel and seat)
The positional relationship between the main wheels 34 and 36, the auxiliary wheels 38, and the seat portion 40 in the wheelchair 30 of the present embodiment will be described with reference to FIG. FIG. 10 is a diagram showing the positional relationship between the main wheels 34 and 36, the auxiliary wheels 38, and the seat portion 40 when the wheelchair 30 is viewed from above.

When the center of the main wheels 34 and 36 and the center of the auxiliary wheel 38 are connected, the triangle of the alternate long and short dash line in FIG. 10 is formed. That is, the centers of the main wheels 34 and 36 and the centers of the auxiliary wheels 38 are located at each apex of the triangle of the alternate long and short dash line shown in FIG.

The pair of left and right main wheels 34, 36 are not parallel to each other as in a conventional wheelchair, and are inclined outward by the same angle θ2 with respect to the traveling direction of the wheelchair 30, for example, as shown in FIG. As a result, the distance between the main wheels 34 and 36 becomes wider toward the front of the seat portion 20.

The triangle connecting the centers of the main wheels 34 and 36 and the center of the auxiliary wheels 38 is an isosceles triangle. The height of this isosceles triangle is determined by the mounting position of the auxiliary wheel 38. How far the auxiliary wheel 38 is from the main wheels 34 and 36 is determined in consideration of the stability of the wheelchair 30. The longer the distance between the main wheels 34 and 36 and the auxiliary wheels 38, the better the stability of the wheelchair 30.

The position of the center of gravity of the seat portion 40 is basically located inside the triangle of the alternate long and short dash line, and the entire seat portion 40 is substantially included in the triangle of the alternate long and short dash line. The seat portion 40 may be moved back and forth and left and right from the position shown in FIG. 10, but it is desirable that the position of the center of gravity thereof is at least located inside the triangle of the two-dot chain line. This ensures the stability of the wheelchair 30 when traveling. If the position of the center of gravity of the seat portion 40 deviates from the triangle of the two-dot chain line, the risk of the wheelchair 30 falling in the deviated direction increases.

(Angle of inclination of the main wheel)
As shown in FIG. 10, the pair of left and right main wheels 34, 36 are inclined inward by an angle θ2 with respect to the traveling direction of the wheelchair 30. Since the main wheels 34 and 36 are tilted by an angle θ2 with respect to the traveling direction of the wheelchair 30, the force of the user rowing the main wheels 34 and 36 is the forward propulsion force of the wheelchair 30 in the vertical direction. It is distributed between the force and the lateral propulsion force, which is the lateral propulsion force of the wheelchair 30.

When the angle θ2 is 0 degrees (when the main wheels 34 and 36 are not tilted), all the force by the user rowing the main wheels 34 and 36 becomes the vertical propulsion force (100%). However, if the angle θ2 is not 0 degrees, it is dispersed into the vertical propulsion force and the lateral propulsion force according to the angle θ2.

As a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ2, when the inclination angle θ2 of the pair of main wheels 34 and 36 is within the range of 10 to 45 degrees, forward propulsion is a problem. It was found that it was easy to secure the degree of freedom in the seating surface position.

Further, as a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ2, when the inclination angle θ2 of the pair of main wheels 34 and 36 is within the range of 45 degrees to 80 degrees, lateral propulsion is performed. Was performed without any problem, and it was found that it was easy to secure the degree of freedom in the seating surface position.

FIG. 11 is a graph showing the relationship between the angle θ2 and the vertical propulsion force and the lateral propulsion force.

For example, when the angle θ2 is 15 degrees, the vertical propulsion force is 96% of the vertical propulsion force when the angle θ2 is 0 degrees, and the lateral propulsion force is 90 degrees when the angle θ2 is 90 degrees. The lateral propulsion force of is 1 and becomes 25% of that. When the angle θ2 is 30 degrees, the vertical propulsion force is 87% and the lateral propulsion force is 50%. When the angle θ2 is 45 degrees, the vertical propulsion force is 70% and the lateral propulsion force is 70%.

As described above, when the angle θ2 becomes large, the vertical propulsive force becomes small, and the forward propulsive force of the wheelchair 30 becomes weak. However, when the angle θ2 becomes large, a lateral propulsive force is generated, so that the user can easily change the traveling direction of the wheelchair 30 by changing the operation balance of the left and right main wheels 34 and 36. The angle θ2 may be increased for a user who wants to easily move the wheelchair laterally, and the angle θ2 may be decreased for a user who wants to prioritize the forward movement of the wheelchair.

Therefore, according to the present embodiment, the angle θ2 is determined so that the vertical propulsion force or the lateral propulsion force of the wheelchair becomes a predetermined propulsion force based on the graph of FIG. 11, and the body of the wheelchair user. Wheelchairs can be provided according to the situation and request.

As a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ2, the predetermined propulsive force with respect to the vertical propulsive force of the wheelchair is 50% of the vertical propulsive force when the angle θ2 is 0 degrees. It is desirable that the angle θ2 is within the range of 60 to 25 degrees (the angle θ2 is within the range of 60 to 25 degrees).

Further, as a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ2, the predetermined propulsive force with respect to the lateral propulsive force of the wheelchair is set to 1 when the angle θ2 is 90 degrees. It is desirable that the angle is within the range of 10% to 50% (the angle θ2 is within the range of 5 to 30 degrees).

Furthermore. As a result of the present invention and the like producing and experimenting with wheelchairs having various angles θ2, it is desirable that the angle θ2 of the inclination of the pair of main wheels is within the range of 10 degrees to 45 degrees.

[Modification Embodiment]
Not limited to the above embodiment, various modifications are possible.

In the first embodiment described above, the pair of left and right main wheels 14 and 16 are perpendicular to the ground, but may be tilted with respect to the ground so that the distance between the wheels 10 and the wheelchair 10 becomes narrower toward the upper side. That is, the camper angle of the main wheels 14 and 16 may be negative so that the upper portions of the main wheels 14 and 16 are tilted inward to form a figure eight when the wheelchair 10 is viewed from the front. As a result, the main wheels 14 and 16 are tilted toward the user, so that the user can easily operate the main wheels 14 and 16 with his / her left and right hands.

Further, in the second embodiment described above, the pair of left and right main wheels 34, 36 are perpendicular to the ground, but even if they are tilted with respect to the ground so that the distance becomes narrower toward the upper side of the wheelchair 3. good. That is, the camper angle of the main wheels 34 and 36 may be negative so that the upper portions of the main wheels 34 and 36 are tilted inward to form a figure eight when the wheelchair 30 is viewed from the front. As a result, the main wheels 34 and 36 are tilted toward the user, so that the user can easily operate the main wheels 34 and 36 with his left and right hands.

Further, in the above-described embodiment, the wheelchair is supported by a pair of main wheels and one auxiliary wheel, but the number of auxiliary wheels may be two or more.

The notation, expression, mode, etc. in the above embodiment are examples, and are not limited thereto.

10 ... Wheelchair 12 ... Body frame 12a, 12b ... Main frame 12c ... Coupling frame 12d, 12e ... Seat support frames 14, 16 ... Main wheels 14a, 16a ... Tires 14b, 16b ... Hand rims 14c, 16c ... Rotating parts 14d, 16d ... Spokes 18 ... Auxiliary wheels 20 ... Seat 20a ... Seat surface 20b ... Backrest 22 ... Small rubber tires 24 ... Bearings 26 ... Rotating parts 28 ... Tire rubber parts 30 ... Wheelchairs 32 ... Body frames 32a, 32b ... Main frame 32c ... Coupling frame 32d, 32e ... Seat support frame 34, 36 ... Main wheels 34a, 36a ... Tires 34b, 36b ... Hand rims 34c, 36c ... Rotating parts 34d, 36d ... Spokes 38 ... Auxiliary wheels 40 ... Seat 40a ... Seat surface 40b ... Backrest Part 42 ... Small rubber tire 44 ... Bearing

The wheelchair according to the present invention includes a pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided in front of the seat portion, and the main wheels are provided in the circumferential direction. A wheelchair having a plurality of small tires rotating in the orthogonal direction of the wheelchair having tires arranged along the circumference, and the distance between the pair of main wheels increases as it goes to the front of the seat portion. It is characterized by.

Further, according to the present invention, a pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided in front of the seat portion are provided, and the main wheels are provided in the circumferential direction. In a wheelchair having tires in which a plurality of small tires rotating in the orthogonal direction are arranged along the circumference, the distance between the pair of main wheels becomes wider toward the front of the seat, so that the driving operation is performed. It is easy to provide a wheelchair that can reduce the risk of rolling over.

The wheelchair 30 of the present embodiment is a so-called rear two-wheel type wheelchair 30 in which a pair of left and right main wheels 34 and 36 are located on the side opposite to the traveling direction of the wheelchair 30, and auxiliary wheels 38 are located in the traveling direction of the wheelchair 30. Is.

Claims (3)

A pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided behind the seat portion are provided, and the main wheels rotate in a direction orthogonal to the circumferential direction. A wheelchair with tires in which multiple small tires are arranged along the circumference.
A wheelchair characterized in that the distance between the pair of main wheels becomes narrower toward the front of the seat portion. A pair of main wheels, a seat portion provided between the pair of main wheels, and an auxiliary wheel provided in front of the seat portion are provided, and the main wheels rotate in a direction orthogonal to the circumferential direction. A wheelchair with tires in which multiple small tires are arranged along the circumference.
A wheelchair characterized in that the distance between the pair of main wheels becomes narrower toward the front of the seat portion. In the wheelchair according to claim 1 or 2.
The vertical propulsion force or the lateral propulsion force of the wheelchair is based on a graph showing the relationship between the inclination angle of the pair of main wheels with respect to the traveling direction of the wheelchair and the vertical propulsion force or the lateral propulsion force of the wheelchair. A wheelchair characterized in that the angle of inclination of the pair of main wheels is determined so as to have a predetermined propulsive force.

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