JP2004290275A - Wheelchair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To increase the usability and safety characteristics and running performance of a wheelchair by making rear auxiliary wheels easily vertically movable by a simple link mechanism. <P>SOLUTION: In the wheelchair, in which main wheels 3 are provided on both sides of a frame 1 which supports a seat part 2, and a pair of front wheels 6 are provided at the front section of the frame, a pair of leg rods 10 are pivotally attached to the rear section of the frame in a manner to be freely rotatable in the vertical plane, respectively, the rear auxiliary wheels 12 are provided on the ends of the leg rods, and an extending rod part 13 which extends on the lower side of the leg rod is provided on the rear side lower part of the frame. Then, first links 16 are each pivotally attached to the extending rod part in a manner to be freely rotatable on the same plane as the leg rod, and the upper end of second links 18 are each pivotally attached to a part which extends to a higher part than the leg rod of the first link, and the lower end of the second link is pivotally attached to the leg rod. By rotating the first link by a handle operation, the rear auxiliary wheels are kept in a descent state, and the main wheels are kept in a floated state from the grounded surface. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
TECHNICAL FIELD The present invention relates to a wheelchair provided with a rear auxiliary wheel that can move up and down, thereby improving traveling performance, safety, and usability, and a lifting mechanism of the rear auxiliary wheel.
[0002]
[Prior art]
[Patent Document 1]
Japanese Patent No. 3072462 [Patent Document 2]
Japanese Utility Model Laid-Open No. 6-9672 [Patent Document 3]
Japanese Patent Application Laid-Open No. 2002-177336
A wheelchair having an auxiliary wheel provided behind a main wheel is known from Patent Documents 1 and 2 described above. In addition, a wheelchair in which the auxiliary wheels are configured to be able to move up and down and the main wheels are kept in a floating state from a ground contact surface by setting the auxiliary wheels in a descending state is known from Patent Document 3.
[0004]
[Problems to be solved by the invention]
By the way, when the main wheels are lifted by lowering the auxiliary wheels, the weight of the wheelchair and the weight of the user are applied to the auxiliary wheels, so that the weight becomes very heavy, and manual operation becomes difficult. For this reason, it has been considered to provide a hydraulic mechanism or an electric mechanism. However, the addition of these mechanisms further increases the weight of the wheelchair, impairs the running performance and significantly increases the manufacturing cost.
Therefore, it was conventionally difficult to lower the auxiliary wheels while being in a wheelchair. In addition, the mechanism for holding the auxiliary wheels in the lowered state has conventionally had to be a complicated structure as shown in Patent Document 3, so that the weight increases and the manufacturing cost increases. There was a problem of becoming.
SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and to make it possible to easily move up and down an auxiliary wheel by a simple link mechanism.
[0005]
[Means for Solving the Problems]
Therefore, the wheelchair of the present invention, in a wheelchair in which a main wheel is rotatably provided on both sides of a frame supporting a seat portion, and a pair of front wheels whose directions can be freely changed at the front of the frame are provided. A pair of leg rods extending rearward at the rear are pivotally connected to each other so as to be rotatable in a vertical plane, and a rear auxiliary wheel whose direction can be freely changed is provided at the tip of the leg rod, and at the lower rear part of the frame. An extension rod portion extending below the leg rod is provided, and a first link extending to a position above the leg rod is pivotally attached to the extension rod portion so as to be rotatable in the same plane as the leg rod. An upper end of a second link shorter than the first link is pivotally attached to a portion of one link extending to an upper portion of the leg, and a lower end of the second link is pivotally attached to the leg, and the handle is operated. By rotating the first link, the leg is lowered by the second link. And the pivot portion of the second link and the leg bar slightly intersects the first link, thereby holding the rear auxiliary wheel in a lowered state, and the main wheel is maintained in a floating state from the ground contact surface. It is characterized by doing so.
For this reason, it is constituted by a small number of parts, and the manufacturing cost of the wheelchair can be reduced, and the lifting and lowering of the rear auxiliary wheel can be easily performed by manual operation while being on the wheelchair.
[0006]
Further, the present invention provides the wheelchair, wherein the rear auxiliary wheels are provided so as to be able to freely rise within a predetermined allowable range, so that the frame is tilted rearward and the main wheels and the rear auxiliary wheels support the frame. The front wheel is configured to float from the ground contact surface.
For this reason, the fall accident of the wheelchair backward is prevented, and it becomes easy to run the wheelchair over the step.
[0007]
Further, the present invention is characterized in that, in the wheelchair, handle levers are provided on both sides of the frame, and the handle lever and the first link are connected via a connecting rod.
This configuration makes it easier for a person in a wheelchair to raise and lower the rear auxiliary wheel.
[0008]
In the wheelchair of the present invention, the rear auxiliary wheel elevating mechanism pivots a leg at the rear of the frame so as to be rotatable in a vertical plane, and provides a rear auxiliary wheel at a tip of the leg to provide a rear auxiliary wheel. An extension rod portion extending below the leg rod is provided at the lower side, and a first link extending to an upper portion of the leg rod is pivotally attached to the extension rod portion so as to be rotatable in the same plane as the leg rod. An upper end of a second link shorter than the first link is pivotally attached to a portion of the first link extending to a position above the leg, and a lower end of the second link is pivotally attached to the leg. By rotating the first link by operating the handle, the leg is pushed down by the second link, and the pivoting portion between the second link and the leg slightly crosses the first link, whereby the rear assist is formed. The wheel is maintained in a lowered state.
The lifting and lowering mechanism allows the rear auxiliary wheel to be raised and lowered manually and lightly, and does not require any additional engaging parts to keep the rear auxiliary wheel in the lowered state, thus reducing weight and cost. Is possible.
[0009]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, a wheelchair according to the present invention will be described with reference to the drawings. 1 to 4 show an embodiment in which the present invention is applied to a so-called self-operating wheelchair. In the figure, 1 is a frame-shaped frame made of a light metal pipe supporting a seat 2, 3 is a large-diameter main wheel rotatably provided on a main shaft 4 protruding from both sides of the frame, and 5 is a main wheel. A handle ring 6 fixed to the outer surface of the wheel is a pair of front wheels provided with a branch pipe 7 fixed to the front portion of the frame, and the main body 3 and the front wheel 6 allow the frame 1 to run. Supported by In addition, the front wheel 6 is a thing whose direction can be freely changed (a so-called caster).
[0010]
Thus, a bearing piece 8 is projected from the rear portion of the frame 1, and a pair of rearwardly extending leg rods 10 are pivotally attached to each other by a pivot 9 inserted through the bearing piece so as to be rotatable in a vertical plane. A rear auxiliary wheel (a so-called caster) 12 whose direction can be freely changed via a branch pipe 11 is provided at the tip of the leg rod. An extension rod portion 13 extending below the leg rod 10 is provided at a lower rear portion of the frame 1, and a pivot 15 is inserted through a bearing piece 14 provided on the extension rod portion, and a first link is formed by the pivot 15. 16 is pivotally mounted so as to be rotatable in the same plane as the leg rod 10. The first link 16 is composed of two flat bars located on both sides of the leg rod 10 as shown in FIG. Then, a pivot 17 is inserted into a portion of the first link 16 extending to a position higher than the leg rod 10, and the upper end of a second link 18 shorter than the first link is connected to the first link via the pivot 17. Pivot to 16. The second link 18 is also composed of two flat bars located on both sides of the leg 10 as in the case of the first link. Then, a pivot 20 is inserted through a bearing piece 19 protruding from the lower side of the leg 10, and the lower end of the second link 18 is pivotally connected to the leg via the pivot 20.
[0011]
Reference numeral 21 denotes a stopper made of an elastic body fixed by inserting a fixed shaft 22 near the base end of the leg rod 10, and the first link 16 is moved forward by the first link 16 hitting the stopper. The rotation range is limited. Further, the rear auxiliary wheel 12 can be moved up and down by the rotatable provision of the leg rod 10, but the height of the rear auxiliary wheel 12 is predetermined by the collision of the leg rod 10 with the pivot 20. To be limited within the allowable range.
[0012]
A guide frame 23 is fixed to both outer surfaces of the frame 1 and a bearing portion 24 is provided at a lower portion of the frame 1. A handle lever 26 is inserted into the guide frame 23, and a lower end of the handle lever 26 is attached to the bearing. The handle lever 26 is pivotally attached to the frame 1 via a pivot 27 inserted through the portion 24, so that the handle lever 26 is provided to be tiltable in the front-rear direction, and an L-shaped connecting rod 28 is provided at a substantially intermediate portion of the handle lever. The handle lever 26 and the upper end of the first link 16 are connected via the connecting rod 28 by being pivotally connected via a pivot 29 and penetrating the pivot 17 through the rear end of the connecting rod 28. I do. Reference numeral 30 denotes a spherical grip provided at the upper end of the handle lever 26, 31 denotes a brake device for braking the rotation of the main wheel 3, and 32 denotes a footrest.
[0013]
The wheelchair thus configured normally travels when the main wheel 3 and the front wheel 5 are in contact with the ground, a person sits on the seat 2 and the main wheel 3 is manually rotated. At this time, since the rear auxiliary wheel 12 is provided on the leg rod 10 so that the height of the rear auxiliary wheel 12 is limited within a predetermined allowable range, even if the rear auxiliary wheel 12 is inclined rearward as shown in FIG. It is supported and fall prevention is safe. Further, when the frame 1 is tilted backward, the front wheel 5 rises from the ground contact surface, so that if the vehicle advances in this state, it can easily get over a step and the traveling performance is greatly improved.
[0014]
Further, by pushing the handle lever 26 in the direction shown by the arrow in FIG. 6, the connecting rod 28 is pulled forward, and the first link 16 is rotated in the direction shown by the arrow, thereby erecting the first link 16. The first link 16 pushes the second link 18 via the pivot 17 in the course of its rotation, and the second link 18 pushes down the leg 10 via the pivot 20. For this reason, the rear auxiliary wheel 12 descends and the main wheel 3 floats from the ground contact surface. As shown in an enlarged manner in FIG. 7, the first link 16 hits the stopper 21 when the first link 16 slightly intersects the pivotal connection portion between the second link 18 and the leg 10, that is, the pivot 20. Therefore, the rear auxiliary wheel 12 is held in the lowered state, and the main wheel 3 can be maintained in a state of floating above the ground contact surface as shown in FIG. If the handle lever 26 is returned to its original position, the first link 16 separates from the stopper 21 and passes over the pivot 20, so that the rear auxiliary wheel 12 can be easily returned to the original raised state.
[0015]
In this manner, in the rear auxiliary wheel elevating mechanism, the upper end of the second link 18 shorter than the first link is pivotally mounted on the upper portion of the first link 16, and the lower end of the second link is connected to the leg rod 10. Since the first link 16 is pivotally connected and rotated by operating the handle, the leg 10 can be strongly pushed downward by leverage of the two links. For this reason, even if the user is in a wheelchair or is weighed, it can be manually operated lightly. The wheelchair is supported by the front wheel 5 and the rear auxiliary wheel 12 when the main wheel 3 rises from the ground contact surface, so that the traveling direction can be freely changed, and both the rotation and the lateral movement can be freely performed.
[0016]
Although not shown, it is possible to attach a spring for floating from the ground when the rear auxiliary wheel 12 is not used. This wheelchair is not limited to the self-operating type shown in this embodiment, but can be applied to any type such as nursing care, folding type, fixed type and the like.
[0017]
FIG. 8 shows another embodiment of the wheelchair of the present invention. In this embodiment, an extension handle 33 is provided on the first link 16. The same reference numerals in FIG. 8 as those in FIG. 3 indicate the same parts. In this embodiment, a caregiver or a person in this wheelchair can directly rotate the first link 16 by putting a hand on the extension handle 33. Even with such a configuration, the same light operation can be performed by the function of the leverage function if the caregiver or the person pulls the extension handle while sitting on the wheelchair by the leverage function. Therefore, in the present invention, it is not necessary to provide a handle lever or a connecting rod as in the above embodiment.
[0018]
【The invention's effect】
As described above, the lifting and lowering mechanism of the rear auxiliary wheel according to the present invention has a very simple configuration in which the rear auxiliary wheel can be raised and lowered by the leg rod, the first link and the second link, and requires a small number of parts. Therefore, the wheelchair can be equipped at low cost. The wheelchair provided with this elevating mechanism can raise and lower the rear auxiliary wheel manually and conveniently, so that it has useful effects such as improved usability, improved safety and running performance.
[Brief description of the drawings]
FIG. 1 is a perspective view showing an embodiment of a wheelchair according to the present invention.
FIG. 2 is a partial cross-sectional side view of the wheelchair of FIG.
FIG. 3 is an enlarged view of a main part of FIG. 2;
FIG. 4 is a plan view of a main part of the wheelchair of FIG. 1;
FIG. 5 is an operation state diagram of FIG. 2;
FIG. 6 is an operation state diagram of FIG. 2;
FIG. 7 is an enlarged view of a main part of FIG. 6;
FIG. 8 is a side view of a main part showing another embodiment of the wheelchair according to the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Frame 2 Seat part 3 Main wheel 6 Front wheel 8 Bearing piece 9 Axis 10 Leg rod 12 Rear auxiliary wheel 13 Extension rod part 14 Bearing piece 15 Axis 16 First link 17 Axis 18 Second link 19 Bearing piece 20 Axis 21 Stopper 26 Handle Lever 28 Connecting rod

Claims (4)

In a wheelchair in which main wheels are rotatably provided on both sides of a frame supporting a seat portion and a pair of front wheels whose directions can be freely changed are provided at a front portion of the frame, a pair of legs extending rearward at a rear portion of the frame. Each of the rods is pivotally mounted in a vertical plane so as to be freely rotatable, and a rear auxiliary wheel whose direction can be freely changed is provided at the tip of the leg rod, and extends below the leg rod at a rear lower portion of the frame. An extension rod portion is provided, and a first link extending to an upper portion of the extension rod portion is pivotally connected to the extension rod portion so as to be rotatable in the same plane as the extension rod, and the extension link portion is provided with an extension rod portion. An upper end of a second link shorter than the first link is pivotally attached to a portion extending to the upper portion, a lower end of the second link is pivotally attached to the leg bar, and the first link is rotated by operating a handle. The leg link is pushed down by the second link, and the second link The rear auxiliary wheel is held in a lowered state by slightly intersecting the first link with a pivot portion between the main wheel and the leg rod, so that the main wheel is maintained in a floating state from the ground contact surface. wheelchair. By providing the rear auxiliary wheel so as to be able to freely rise within a predetermined allowable range, when the frame is tilted rearward and the main wheel and the rear auxiliary wheel support the frame, the front wheel rises from the ground contact surface. 2. The wheelchair according to claim 1, wherein the wheelchair is configured as follows. The wheelchair according to claim 1 or 2, wherein a handle lever is provided on both sides of the frame, and the handle lever and the first link are connected via a connecting rod. A leg rod is pivotally attached to the rear part of the frame so as to be rotatable in a vertical plane, a rear auxiliary wheel is provided at the tip of the leg rod, and an extension rod part extending below the leg rod at the rear lower part of the frame. And a first link extending to an upper portion of the extension rod is pivotally connected to the extension rod so as to be rotatable in the same plane as the leg rod, and extends to an upper portion of the first link above the leg rod. The upper end of a second link shorter than the first link is pivotally connected to the portion, the lower end of the second link is pivotally connected to the leg rod, and the first link is rotated by operating a handle, thereby forming the second link. As a result, the leg is depressed downward, and the rear auxiliary wheel is held in a lowered state by the pivot portion of the second link and the leg slightly crossing the first link. Lifting mechanism of the rear auxiliary wheel in the wheelchair.

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