The present invention generally relates to a manual wheelchair (hereinafter, simply referred to as a “wheelchair”). More specifically, the present invention relates to a lightweight and inexpensive wheelchair that can be easily operated by either a right or left hand.
A wheelchair is configured so that a wheelchair user (hereinafter, simply referred to as a “user”) operates right and left wheels by his/her hands to move forward, backward, right turn, and left turn. However, it is difficult for a person with a disability on either the right or left side of the body to use a general wheelchair because they cannot use both hands freely. Therefore, a single-hand-operated wheelchair that can be operated with only a healthy hand, even if the right or left body is disabled, has been proposed (see Patent Document 1). The wheelchair described in Patent Document 1 is configured such that the wheelchair disposes a double handrim outside a wheel on a side, where a healthy half of the body of a user is located so that the movement of the wheelchair can be controlled by operating the handrim with the healthy hand.
On the other hand, a wheelchair has also been proposed in which a rotary shaft connecting right and left wheels and an operating device such as a lever and a clutch are interlocked, and these operating devices are operated by a single hand to control the wheelchair as desired (see Patent Documents 2 to 4). Further, the wheelchairs described in Patent Documents 5 and 6 were developed by the present inventor and have a feature that can be easily operated by either a right or left hand.
However, the wheelchair described in Patent Document 1 is not convenient for wheelchair users, because the handrim for operation is disposed on only one side of the right and left sides, and the operable side is predetermined. For this reason, there is an issue that two types of operation, both right and left, have to be manufactured, which contributes to high costs. Further, the wheelchair described in Patent Document 2 requires the operation of a lever, and the wheelchair described in Patent Document 3 requires a user to tilt his/her body to the right or left during operation, which is a physical burden. There was an issue that the physical burden was excessive. Also, the wheelchair described in Patent Document 4 has an issue in that the configuration corresponding to the constant speed movement is not shown, and the usability is not good. Furthermore, although the wheelchairs described in Patent Documents 5 and 6 are fortunately well received, the former has a relatively large number of portions, so there is an improvement in that the weight of the wheelchair is slightly heavier. As for the latter, there is an improvement in that it takes time and effort depending on the operation because it is not possible to turn only the wheel on the opposite side with a single hand.
The present invention has been developed given such a situation, and the objective of the present invention is to provide a lightweight and inexpensive wheelchair that can be easily operated by either a right or left hand.
According to claim 1 of the present application, the present invention provides a single-handedly operable wheelchair having a frame, a right wheel and a left wheel, a right caster and a left caster, a seat, and a pair of right and left circular cross-sectional handrims concentrically disposed with an axle of each wheel, the wheelchair including: each of the handrims formed as separate bodies, and having a first portion located at an inner lower portion of the circular cross-section and a second portion occupying a portion other than the first portion of the circular cross-section; the first portion connected to handrim spokes; the second portion connected to a base of each wheel; and a drive mechanism for transmitting a first rotational force generated by the first portion of the handrim on one side to the wheel on another side, and for transmitting a second rotational force generated by the first portion of the handrim on the other side to the wheel on the one side. A third rotational force generated by the second portion of the handrim on the one side and/or the other side is transmitted to the wheel on the corresponding side. The drive mechanism has the axle on the one side connected to the handrim spokes on the one side, the axle on the other side connected to the axle on the one side via a rotary shaft and connected to the handrim spokes on the other side, a first two-way clutch disposed on the axle on the one side, and a second two-way clutch disposed on the axle on the other side. The first two-way clutch is configured to transmit the second rotational force to the wheel on the one side, is configured not to transmit the first rotational force to the axle on the one side, and is configured not to transmit the third rotational force generated by the second portion of the handrim on the one side to the axle on the one side. Further, the second two-way clutch is configured to transmit the first rotational force to the wheel on the other side, is configured not to transmit the second rotational force to the axle on the other side, and is configured not to transmit the third rotational force generated by the second portion of the handrim on the other side to the axle on the other side.
According to claim 2 of the present application, regarding the wheelchair of claim 1, the present invention provides the single-handedly operable wheelchair, wherein a first key provided on the outer end of the axle on the one side is installed on a first receiving portion rotatably attached to the outer end of the axle on the one side, and is engaged with a first key groove wider than the first key. A second key provided on the outer end of the axle on the other side is installed on a second receiving portion rotatably attached to the outer end of the axle on the other side, and is engaged with a second key groove wider than the second key. By rotating the receiving portion connected to the handrim spokes on the corresponding side and had a control plate with a notch, the rotational force from the handrim spokes on the corresponding side is transmitted to the axle on the corresponding side. The first two-way clutch has first rollers for cutting off transmission of the first rotational force or for carrying out transmission of the second rotational force between the axle on the one side and the wheel on the one side, and has a first retainer for retaining the first rollers at a predetermined location. The second two-way clutch has second rollers for cutting off transmission of the second rotational force or for carrying out transmission of the first rotational force between the axle on the other side and the wheel on the other side, and has a second retainer for retaining the second rollers at a predetermined location. By rotating the control plate by rotating the first receiving portion, and by rotating the first retainer by engaging the notch with a protrusion provided on the first retainer, the first rotational force is not transmitted from the axle on the one side to the wheel on the one side without locking the rotation of the first rollers, and the first rotational force is transmitted from the axle on the other side to the wheel on the other side. Further, by rotating the control plate by rotating the second receiving portion, and by rotating the second retainer by engaging the notch with a protrusion provided on the second retainer, the second rotational force is not transmitted from the axle on the other side to the wheel on the other side without locking the rotation of the second rollers, and the second rotational force is transmitted from the axle on the one side to the wheel on the one side.
According to an embodiment of the present invention, there is provided a wheelchair capable of performing moving control by simple operation using only either hand. In the wheelchair according to the embodiment of the present invention, a handrim is divided into a plurality of portions, and it is not necessary to change the way of grasping the handrim so that it is easy to use. Further, the wheelchair can be manufactured at light weight and low cost because the number of portions is small.
The wheelchair according to the embodiment of the present invention can even be used by anyone other than a person with a disability on either the right or left side of the body. That is, the wheelchair according to the embodiment of the present invention is useful when a person who has healthy both hands moves in the wheelchair with an article (smartphone, tableware, umbrella, or the like) in a single hand. It is also useful when playing sports such as tennis or basketball in the wheelchair. Further, as will be described in detail later, the wheelchair according to the embodiment of the present invention is useful compared to a conventional both-hands-wheelchair, in that it can be used for an uphill movement while resting according to the physical strength of the user.
Next, a wheelchair, according to an embodiment of the present invention, will be described in detail with reference to the drawings.
According to the embodiment of the present invention, as shown by a reference numeral 10 as a whole in
The wheelchair 10 also has a handrim 20a disposed concentrically of an axle 24a of the right wheel 14a. As shown in
As shown in
The first portion 20a1 of the handrim 20a is connected to handrim spokes 22a, and the second portion 20a2 is connected to a base of the right wheel 14a.
Next, the configuration of the driving mechanism of the wheelchair 10 will be described with reference to
The axle 24a is rotatably supported in the axle holder 28a (and therefore the frame 12) by bearings 26a. Also, the left side portion of the wheelchair 10 is provided with an axle 24b having the same configuration at the corresponding location. The axle 24a and the axle 24b form one rotating shaft via a columnar rotary shaft 32 and connection sleeves 32a, 32b.
The axle holder 28a shown in
In
In
The two-way clutch 34a is attached to the axle 24a outside the axle holder 28a. Here, the two-way clutch 34a refers to a clutch having the following functions. When inputting to the axle 24a, a rotational force is transmitted to an inner ring 34a1, but not to an outer ring 34a7 described later, and can be transmitted only to an outer ring 34b7 of a two-way clutch 34b on the opposite side, when inputting to the outer ring 34a7, a rotational force cannot be transmitted to the axle 24a, and when inputting to the axle 24b, a rotational force can be transmitted to the outer ring 34a7 via the rotary shaft 32, the axle 24a and the inner ring 34a1.
The two-way clutch 34a includes the inner ring 34a1 of a regular polygon (a regular hexagon in the example shown in
One roller 34a3 is respectively arranged on each side of the regular polygonal inner ring 34a1, as shown in
A substantially ring-shaped switching plate 34a5 shown in
Outside the retainer 34a4, the outer ring 34a7 is rotatably supported by the retainer 34a4 via bearings 34a6. The outer ring 34a7 has a substantially cylindrical shape and is connected to wheel spokes 14a1 of the right wheel 14a.
The configuration of the two-way clutch 34a as described above is known (for example, a two-way clutch manufactured by NTN Corporation (English version catalog)).
In the above description, the configuration of the right side portion of the wheelchair 10 has been mainly described, but the left side portion of the wheelchair 10 also has substantially the same configuration as the right side portion. That is, when describing the main components, 20b represents a handrim, 22b represents a handrim spoke, 24b represents an axle, and 34b represents a two-way clutch.
The operation of the two-way clutches 34a and 34b configured as above will be described with reference to
That is, in the two-way clutch 34a, the inner ring 34a1 rotates, and the rotation of the control plate 25a2 causes the retainer 34a4 to rotate in the same direction. The rollers 34a3 are located between the left end portions 34a1b and the intermediate portions 34a1a (same position as in
On the other hand, in the two-way clutch 34b, the inner ring 34b rotates, but the control plate 25b2 does not rotate because it is the third time point before the one end of the notch 25b3 abuts the protrusion 34b4-4 as described above. Therefore, the retainer 34b4 does not rotate either. When the inner ring 34b1 rotates clockwise, the rollers 34b3 move from positions between the intermediate portions 34b1a and the left end portions 34b1b on the side of the cam surfaces of the inner ring 34b1 to the left end portions 34b1b (during this period, the rotational force of the inner ring 34b1 is not transmitted to the outer ring 34b7). When the rollers 34b3 reach the left end portions 34b1b, the rotation of the rollers 34b3 is locked (see
As described above, by setting a time difference in the rotation of each component (the axles 24a and 24b, the inner rings 34a1 and 34b1, the control plates 25a2 and 25b2, the retainers 34a4 and 34b4) caused by the rotation of the handrim spokes 22a, it is configured so that the rotational force is not transmitted, to the right wheel 14a on the same side as the handrim spokes 22a, but is transmitted to the left wheel 14b on the opposite side. That is, when the handrim spokes 22a are rotated, the axle 24a rotates after a short period of time (the one end of the key groove 25a1 abuts the key 24a1), and the axle 24b also rotates via the rotary shaft 32. When the axles 24a, 24b rotate, the inner rings 34a1 and 34b1 non-rotatably attached to the axles 24a and 24b also rotate. When the handrim spokes 22a are further rotated, after a certain period of time has elapsed (the one end of the notch 25a3 abuts the protrusion 34a4-4), and when the control plate 25a2 rotates, the retainer 34a4 also begins to rotate. However, since 25b2 does not rotate, the retainer 34b4 does not rotate. When the retainer 34a4 rotates, the rotation of the inner ring 34a1 is not transmitted to the outer ring 34a7 because the rollers 34a3 are not locked. On the other hand, since the retainer 34b4 does not rotate, the rollers 34b3 are locked and the rotation of the inner ring 34b1 is transmitted to the outer ring 34b7.
When the second portions 20a2 and 20b2 of the handrims 20a and 20b are grasped and rotated, the rotational force is transmitted to the outer rings 34a7 and 34b7 of the two-way clutches 34a and 34b. When the outer rings 34a7 and 34b7 rotate clockwise (solid line arrows in
If it operates similarly to the two-way clutches 34a and 34b as described above, the two-way clutches of another configuration may be adopted.
The operation of the wheelchair 10 provided with the two-way clutches 34a and 34b will be described with reference to
When attempting to move straight (forward or backward) by the right hand, both the first portion 20a1 and the second portion 20a2 of the handrim 20a are grasped by the right hand and are rotated forward or backward (see
When attempting to move straight (forward or backward) by the left hand, both the first portion 20a1 and the second portion 20a2 of the handrim 20a are grasped by the left hand and are rotated forward or backward (see
When attempting to turn left (forward or backward) with the right hand, only the second portion 20a2 of the handrim 20a is grasped by the right hand and is rotated forward or backward (see
When attempting to turn right (forward or backward) by the left hand, only the second portion 20b2 of the handrim 20b is grasped by the left hand and is rotated forward or backward (see
When attempting to turn right (forward or backward) by the right hand, only the first portion 20a1 of the handrim 20a is grasped by the right hand and is rotated forward or backward (see
When attempting to turn left (forward or backward) by the left hand, only the first portion 20b1 of the handrim 20b is grasped by the left hand and is rotated forward or backward (see
By changing the two portions of the handrims 20a and 20b by the right and left hands, it is possible to comfortably perform an uphill movement. That is, for example, first, the two portions of the handrims 20a and 20b are grasped by both hands and rotated forward to perform the uphill movement. When rowing once and then stopping, it is enough to grasp both the first portion 20a1 and the second portion 20a2 of the handrim 20a by the right hand without rotating. Next, the left hand is separated from the first portion 20b1 and the second portion 20b2 of the handrim 20b and returned to the first rowing position, and both the first portion 20b1 and the second portion 20b2 of the handrim 20b are grasped without the rotation by the left hand to keep the stop. Next, the right hand is separated from the first portion 20a1 and the second portion 20a2 of the handrim 20a and returned to the first rowing position, and both the first portion 20a1 and the second portion 20a2 of the handrim 20a are grasped without the rotation by the right hand to keep the stop. While grasping the two portions of the handrims 20a and 20b by both hands, the handrims are rotated forward to perform the uphill movement. This series of operations are repeated to perform the uphill movement. In this way, by changing the right and left hands and operating, unlike the conventional both-hands-operated wheelchair, it is possible to perform the uphill movement while resting according to the physical strength of the user.
In the above description, the right side portion of the wheelchair 10 has been described, but the left side portion is the same as the right side portion.
It is needless to say that the present invention is not limited to the above-described embodiments, various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention.
For example, the details of the components of the wheelchair shown are merely exemplary and these details may be modified.
Number | Date | Country | Kind |
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2020-208152 | Dec 2020 | JP | national |
This application claims the benefit of priority and is a Continuation application of the prior International Patent Application No. PCT/JP2021/034281, with an international filing date of Sep. 17, 2021, which designated the United States, and is related to the Japanese Patent Application No. 2020-208152, filed Dec. 16, 2020, the entire disclosures of all applications are expressly incorporated by reference in their entirety herein.
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Number | Date | Country | |
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Number | Date | Country | |
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Parent | PCT/JP2021/034281 | Sep 2021 | US |
Child | 18201758 | US |