JP2004089340A - Tumble preventing mechanism of wheelchair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a tumble preventing mechanism of a wheelchair whose front caster can be easily lifted without causing feeling of insecurity even when the center of gravity of the wheelchair is shifted backward by backward weight shift in the case a person on the wheelchair goes over bumps or turns around in a narrow space. <P>SOLUTION: The tumble preventing mechanism of the wheelchair is equipped with a caster 18, a fixing rod 19 which extends in an approximately vertical direction and pivotally fixes the caster at the lower end, a rear fixing member 20 of a uniform length protruding from the fixing rod to the side of wheelchair, support arms 23, 24 whose each one end is rotatably and axially attached to the rear fixing member 20 and the other end is rotatably and axially attached in the downward direction to the backside of a crossframe downwardly disposed from the back to the front of a sideframe of the wheelchair, and an elastic member 25 whose one end is rotatably and axially attached to the support arm and the other end is rotatably and pivotally attached in the middle of a backside member of the wheelchair. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a wheelchair tipping prevention mechanism that can be mounted on the rear of a wheelchair and lift the front casters of the wheelchair when an assistant pushes down on the steering wheel or when the occupant shifts the center of gravity of the wheelchair to the rear.
[0002]
[Prior art]
Regarding the operation of the wheelchair, whether the occupant runs on its own or the caregiver, it is difficult to operate in a house with a threshold or in a narrow place. In particular, moving from a room having a step such as a threshold to a room requires moving over a caster vehicle provided at the front of the vehicle on the threshold or the like, which is onerous. In narrow places, a wheelchair with a small turning radius is desirable. In order to solve such a problem, a fall prevention mechanism has been devised. The overturn prevention mechanism is mounted so that the wheelchair does not fall backward when the wheelchair is tilted backward and the front caster wheel is lifted to get over a step. As a fall prevention mechanism, a caster wheel is provided at the rear of the wheelchair, and when the passenger shifts weight to the rear of the wheelchair or when the assistant pushes down the handle and lifts the front caster of the wheelchair, it falls over to the rear. Various shapes have been devised as a method of preventing the movement of a wheelchair and lifting a caster wheel in front of a wheelchair to ride over a step such as a threshold.
[0003]
For example, in Japanese Patent Application Laid-Open No. 2001-314450, a caster, a fixed rod extending in a substantially vertical direction, and a caster is rotatably fixed to a lower end, and one end is pivotally mounted on the fixed rod and the other end is fixed. And a support arm pivotally mounted on a rear pipe of a wheelchair, and a telescopic arm having one end pivotally mounted on a fixed rod and the other end pivotally mounted on a member above the wheelchair. And a mechanism for preventing a wheelchair from falling over.
[0004]
In order to get over a step with this fall prevention mechanism, an assistant pulls a handgrip backward, tilts a wheelchair backward, and lifts a front wheel. In other words, when the caregiver pulls the handgrip backward and tilts the wheelchair, the support arm pivotally mounted on the front fixing member rotates so that the rear part of the wheelchair lowers and the front caster rises. It has become. In this case, the distance between the main wheels and the rear casters is reduced by lowering the front side of the support arm and moving the rear casters toward the main wheels. For this reason, the caregiver is in a state of supporting the wheelchair correspondingly, resulting in a burden on the caregiver. Furthermore, when the driver is self-propelled, the center of gravity of the wheelchair is difficult to shift to the rear even if the passenger shifts weight behind the wheelchair, and the rear of the wheelchair sinks down and falls backward to the passenger. There is a problem of giving such anxiety.
[0005]
[Problems to be solved by the invention]
The present invention provides a feeling of anxiety that a passenger in a wheelchair falls over a step or when turning in a narrow place, even if the weight shifts to the rear of the wheelchair and the center of gravity of the wheelchair is shifted rearward. Provided is a wheelchair overturn prevention mechanism that makes it easy to lift a front caster without giving it.
[0006]
[Means to solve the problem]
As a result of intensive studies to solve the above problems, a fixing member is attached to a fixing rod of a caster, one end of a support arm is pivotally attached to the fixing member, and the other end is attached to a cross frame of a wheelchair. By attaching to the shaft, an easy-to-handle fall prevention mechanism was obtained.
[0007]
A first feature of the present invention is that in a fall prevention mechanism attached to a wheelchair having a front caster and a main wheel, the fall prevention mechanism extends substantially vertically with the caster, and the caster is pivotally fixed to a lower end thereof. A fixed rod projecting from the fixed rod to the wheelchair side, a fixed length of a rear fixed member, and one end rotatably mounted on the rear fixed member and the other end being forward from the rear of the side frame of the wheelchair. A support arm pivotally attached to the rear side and downward of the cross frame arranged in the downward direction, and one end pivotally attached to the support arm and the other end to the back of the wheelchair. And a telescopic member rotatably mounted in the middle of the member described above. One end of the support arm is pivotally attached to a fixed length rear fixing member protruding from the fixing rod toward the wheelchair, and the other end of the support arm is pivotally connected to a cross frame provided from the rear of the wheelchair side frame to the front lower end. By wearing, the occupant shifts his / her weight to the rear of the wheelchair and shifts the center of gravity of the wheelchair to the rear, whereby the wheelchair tilts backward and the front caster of the wheelchair can be easily lifted.
[0008]
A second feature of the present invention is the wheelchair overturn prevention mechanism according to claim 1, comprising two support arms. By using two support arms that are pivotally attached to the fixing member, it is possible to receive the weight of the occupant behind the wheelchair and to have a structure in which the pivot does not shake even when rotating.
[0009]
A third feature of the present invention is that at least one of the support arms has a bent portion in which a spring member is urged, and the fall prevention mechanism for a wheelchair according to claim 1 or 2, wherein: It is. By providing a bent portion in which at least one of the support arms is biased by a spring member, when the occupant shifts his / her weight to the rear of the wheelchair and moves the center of gravity of the wheelchair, the rear casters can easily move rearward. .
[0010]
A fourth feature of the present invention is a wheelchair in which the height of an armrest on which the fall prevention mechanism according to any one of claims 1 to 3 is mounted is adjustable. By adjusting the height of the armrests according to the occupant, whether it is a tall person or a short person, the wheelchair is equipped with a fall prevention mechanism that does not get tired even if the person is in a wheelchair for a long time.
[0011]
A fifth aspect of the present invention is a wheelchair having a plurality of wheel mounting holes provided with the overturn prevention mechanism according to any one of claims 1 to 4. In a wheelchair in which the overturn prevention mechanism of the present invention is mounted on a wheelchair having a plurality of wheel mounting holes, a large wheel is mounted when the occupant runs by himself, and a small wheel is replaced when a passenger is present. Can be used.
[0012]
DESCRIPTION OF THE PREFERRED EMBODIMENTS
The wheelchair overturn prevention mechanism of the present invention will be described below in detail with reference to the drawings. The fall prevention mechanism mounted on the wheelchair of the present invention can be mounted on various types of wheelchairs by attaching a fixing member to the lower rear end of the cross frame of the wheelchair, and is limited to the wheelchair shown in the following embodiments. Not something.
[0013]
FIG. 1 shows an example of a wheelchair equipped with a fall prevention mechanism of the present invention. The wheelchair equipped with the fall prevention mechanism of the present invention has a rear frame 11 provided with a backrest, a side frame 13 provided with a seat, and an armrest 12 mounted thereon. A cross frame 15 is provided, and a front caster 16 and a main wheel 17 are mounted on the cross frame 15. An auxiliary frame 22 is provided from the lower frame 21 to the cross frame 15. At the rear of the cross frame 15, one end of the support arm 24 is pivotally mounted slightly downward and slightly behind the auxiliary frame 22. Further, one end of a support arm 23 is rotatably mounted on the upper end of the auxiliary frame 22. The other ends of the support arms 23 and 24 are mounted on the rear fixing member 20 of the rear caster 18. One end of a telescopic rod 25 is mounted on the upper part of the support arm 24 on the rear side. The other end of the telescopic rod 25 was pivotally mounted at the middle of the back pipe. In the wheelchair equipped with the overturn prevention mechanism of the present invention shown in FIG. 1, both the front casters 16 and the rear casters 18 are grounded on a plane centering on the main wheels.
[0014]
When the occupant shifts his / her weight slightly behind the wheelchair and shifts the center of gravity of the wheelchair to the rear, as shown in FIG. 2, the support arms 23 and 24 push the rear casters 18 rearward, and the wheelchair tilts rearward, The caster 16 is lifted. When the wheelchair is moved forward in that state, the front caster 16 rides on the step and can get over the step. In the overturn prevention mechanism 100 of the present invention, when the occupant shifts the weight rearward, the rear casters 18 move rearward, so that the distance between the main wheel 17 and the rear casters 18 further increases, and the rearward casters 18 To increase stability. Furthermore, the fall prevention mechanism 100 of the present invention enables the occupant to climb over a step by himself or rotate in a narrow space when the vehicle runs on its own. In addition, when riding over a step or rotating in a narrow space even when an assistant is present, the assistant can easily lower the rear portion of the wheelchair by pushing down the grip portion 30 of the rear frame 11 and raise the front caster 16. Can be done.
[0015]
As shown in FIG. 3, the structure of the overturn prevention mechanism 100 of the present invention has a fixed length rear fixing member 20 protruding from the fixing rod 19 toward the wheelchair, and one end of each of the support arms 23 and 24 is attached to the rear fixing member 20. It is pivotally mounted on the shaft. The other ends of the support arms 23 and 24 are rotatably mounted on the front fixing member 26 and the auxiliary frame 22. One end of a telescopic member 25 is pivotally mounted on the upper part of the support arm 24 which is pivotally mounted rearward. The other end of the elastic member 25 is rotatably mounted at the center of the rear pipe 11.
[0016]
The supporting arms 23 and 24 are loaded with the weight of the occupant when the front casters 16 are raised, and further, when rotating, a load of torsion due to the rotational motion is provided, so that at least two supporting arms are provided. Is desirable. Further, the support arms 23 and 24 are made of two flat steels so as to sandwich the rear fixing member 20, and reinforcing members 23a and 24a are provided on the back so as to connect the two flat steels, and a lateral force is provided. Is desirable.
[0017]
The support arm 23, which is axially mounted on the front side of the rear fixing member 20, is provided with a bent portion 23b which biases a spring member 23c, so that the center of gravity of the wheelchair can be moved rearward with less force when the weight of the occupant is moved. Can be transferred. In the state shown in FIG. 3, the front casters 16, the main wheels 17, and the rear casters 18 are on the same plane. When the weight is shifted to the rear of the wheelchair, the center of gravity of the wheelchair shifts rearward, and as shown in FIG. 4, the bent portion 23b of the front support arm 23 extends, and the two support arms 23 and 24 move the rear caster 18 rearward. Become almost parallel to push out. A spring member 23c is urged to the bent portion 23b, and when the occupant moves the weight forward or the caregiver lifts the grip portion 30 lightly, the spring urged by the extendable member 25 and the support arm 23 is applied. The rear caster 18 returns to the original position by the force of the member 23c.
[0018]
FIG. 5 shows an example in which the support arm 23 provided on the front side of the rear fixing member 20 is not provided with the bent portion 23b. As shown in FIG. 5, the front casters 16, the main wheels 17, and the rear casters 18 are on the same plane. When the occupant shifts weight to the rear of the wheelchair, the center of gravity of the wheelchair moves rearward and the front casters 16 of the wheelchair can be raised as shown in FIG. However, when the bent portion 23b was not provided on the support arm 23 as compared with the support arm provided with the bent portion 23b, much force was required to push the rear caster 18 backward.
[0019]
FIG. 7A shows a front fixing member 27 attached to the cross frame 15, and one ends of the support arms 23 and 24 are pivotally attached to the front fixing member 27, and one end of the telescopic member 25. An example is shown in which the shaft is mounted slightly forward from the rear of the support arm 24. FIG. 7B shows a state in which the center of gravity of the wheelchair has moved rearward, and the rear casters 18 have been pushed rearward. FIG. 8A shows an example in which the auxiliary fixing member 20a is fixed to the rear fixing member 20, and one ends of the support arms 23 and 24 are attached to the auxiliary fixing member 20a. FIG. 8B shows a state in which the center of gravity of the wheelchair has moved rearward, and the rear caster 18 has been pushed rearward. FIG. 9A is a modification of the support arms 23 and 24, and shows an example in which the position of the bent portion 23b is positioned above the support arm 23 and the method of urging the spring member 23c is changed. FIG. 9B shows a state in which the center of gravity of the wheelchair has moved rearward, and the rear casters 18 have been pushed rearward.
[0020]
FIG. 10 shows a wheelchair in which the height of the armrest 28 can be adjusted in accordance with the occupant's posture by appropriately changing the position of the screw of the armrest adjusting section 29 to provide a fall prevention mechanism of the present invention. 100 shows an example in which 100 is mounted. FIG. 10 shows an example in which two wheel mounting holes 31 are provided. However, by providing a plurality of wheel mounting holes 31, a large wheel is used when the occupant runs by himself, and a small wheel is used when a passenger is present. Depending on the purpose, it is possible to replace a large wheel with a small wheel and use it for various purposes. FIG. 11 shows a state in which the center of gravity of the wheelchair is shifted rearward, the rear casters 18 are pushed rearward, and the front casters 16 are lifted. Further, the overturn prevention mechanism 100 of the present invention can be mounted on a wheelchair provided with a plurality of wheel mounting holes 31 for mounting the main wheels 17.
[0021]
The fall prevention mechanism 100 of the present invention can be attached to any type of wheelchair other than the illustrated one as long as the wheelchair has a portion for pivotally attaching the elastic member 25 and one end of the two support arms 23 and 24. is there. If the front caster 16 is difficult to lift even if the bent portions 23b of the support arms 23 and 24 are provided for a person with a light weight, the position of the main wheel 17 is changed to adjust the position of the center of gravity. A wheelchair with a fall prevention mechanism that is easy to use even for light weight persons can be provided.
[0022]
【The invention's effect】
By pivoting one end of the pivoting member to the support arm of the caster and pivoting the other end to the frame at the rear of the wheelchair, the weight of the occupant can be shifted, or the caregiver can easily push down on the handle. You can lift the front caster. By using two rotating members that are axially attached to one end of the support arm, the weight of the occupant can be received, and a strong structure that does not shake even when rotating can be achieved.
[0023]
Further, by enabling the height of the armrest to be adjusted, the height of the armrest can be adjusted according to a tall user or a short user, so that the user can use it for a long time without fatigue. In addition, by providing a plurality of wheel mounting holes, a large wheel can be exchanged with a small wheel when the occupant travels by himself, and the wheel can be used according to the purpose.
[Brief description of the drawings]
FIG. 1 is a side view of a wheelchair provided with a fall prevention mechanism.
FIG. 2 is a side view in which a wheelchair provided with a fall prevention mechanism is inclined rearward.
FIG. 3 is a partial perspective view of a fall prevention mechanism.
FIG. 4 is a partial perspective view of a fall prevention mechanism.
FIG. 5 is a side view of a wheelchair equipped with another embodiment of a fall prevention mechanism. FIG. 6 is a side view of a wheelchair equipped with another embodiment of a fall prevention mechanism inclined rearward. FIG. 7 is a partial side view of the fall prevention mechanism. FIG.
FIG. 8 is a partial side view of a fall prevention mechanism.
FIG. 9 is a partial side view of a fall prevention mechanism.
FIG. 10 is a side view of a wheelchair in which a fall prevention mechanism is mounted on a wheelchair in which the height of an armrest is adjustable.
FIG. 11 is a side view in which a wheelchair in which a fall prevention mechanism is mounted on a wheelchair in which the height of an armrest is adjustable is inclined backward.
[Explanation of symbols]
100: overturn prevention mechanism 11: rear frame 12: armrest 13: side frame 14: front frame 15: cross frame 16: front caster 17: main wheel 18: rear caster 19: caster bracket 20: rear fixing member 21: lower part Frame 22: Auxiliary frame 23: Support arm 24: Support arm 25: Telescopic member 26: Rotating support part 27: Front fixing member 28: Armrest 29: Armrest adjustment part 30: Holding part 31: Wheel mounting hole

Claims (5)

In a fall prevention mechanism attached to a wheelchair having a front caster and a main wheel, the fall prevention mechanism includes a caster, a fixed rod extending substantially in a vertical direction, and a caster fixed to a lower end to be rotatable. A rear fixing member having a fixed length protruding toward the wheelchair, and a cross frame having one end rotatably mounted on the rear fixing member and the other end disposed downward from the rear of the side frame of the wheelchair to the front. A support arm pivotally attached to the rear side and downward of the wheel, and one end is pivotally attached to the support arm and the other end is pivotable in the middle of a member on the back of the wheelchair. A fall prevention mechanism for a wheelchair, comprising a telescopic member pivotally mounted on the wheelchair. 2. The wheelchair overturn prevention mechanism according to claim 1, comprising two support arms. 3. The wheelchair overturn prevention mechanism according to claim 1, wherein at least one of the support arms has a bent portion to which a spring member is urged. A wheelchair in which the height of an armrest on which the fall prevention mechanism according to any one of claims 1 to 3 is mounted is adjustable. A wheelchair having a plurality of wheel mounting holes provided with the overturn prevention mechanism according to any one of claims 1 to 4.

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