JP2006116081A - Wheelchair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a wheelchair from getting shaky to a floor surface so that a user of the wheelchair or a helper can perform a stable transfer action at the time of the transfer of the user from the wheelchair to a bed, or the like. <P>SOLUTION: A wheelchair lifting mechanism is installed near the caster attaching position of the wheelchair and a part or all of external force acting on casters and the floor surface is shared by the lifting mechanism at the time of the transfer. Since a part of the lifting mechanism is connected to a wheelchair body and an end part comes into contact with the floor surface, it is made difficult to move the wheelchair by frictional force acting on the end part and the floor surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wheelchair, and more particularly to a technique for making it difficult for the wheelchair to move relative to the floor so that the wheelchair does not wobble or move when the user moves between the wheelchair and a bed or the like.

  Wheelchairs are often used for elderly people or persons with disabilities who are difficult to walk and move to a target position that is slightly away from their current position. Consider using this wheelchair in a geriatric health insurance facility. In this case, it is mainly used for going back and forth between a bed, a toilet, a dining table, and the like, but it is general that a caregiver needs assistance when changing from a bed to a wheelchair. This support work is a heavy labor that causes back pain for caregivers, while it also causes stress for wheelchair users.

  A manual wheelchair is generally difficult to move by applying a mechanical brake to a rear wheel, but a caster is difficult to restrain movement due to its structure. In other words, the caster includes a rotating wheel and a swing mechanism that changes the moving direction, but the rotation stop for the former is widely used for office chairs and the like, but there is no swing stop for the latter. In this state, the wheelchair is difficult to move in the traveling direction, but it is a drawback that it is easy to move with respect to the external force from the side. In particular, in the case of a transfer operation, the user moves to the bet or the like while laying the buttocks sideways, so that a lateral force acts on the wheelchair, and thus wobbles easily.

  In an electric wheelchair, an electric brake is applied to a drive wheel, but in a caster, the situation is the same as that of a manual wheelchair and has the same drawbacks. (See Patent Document 1)

It has also been proposed to reduce the wobble by installing mechanical restraint means on the caster separately from the wheelchair and installing the wheelchair on the mechanical restraint means during transfer (see Patent Document 2). There is a drawback that it can only be used in places where static restraint means are installed.
Japanese Patent Application No. 2004-126103 Japanese Patent Application No. 2004-126104

  It is an object of the present invention to prevent the wheelchair from wobbling against the floor surface so that a wheelchair user or a caregiver can perform a stable transfer action when transferring from a wheelchair to a bed or the like.

  A means for solving the problem is to install a wheelchair lifting mechanism in the vicinity of the caster part of the wheelchair. This lifting mechanism can be stored so as not to hinder the traveling during traveling, and bears a part or all of the load acting on the wheelchair caster during transfer. When all the burden is borne, the caster is lifted from the floor, and the wheelchair is supported by the driving wheel and the lifting mechanism. One end of the lifting mechanism is connected to the wheelchair body, and the other end is restrained by the frictional force with the floor surface, so that the wheelchair is fixed to the floor surface. Moreover, when bearing a part of load, a wheelchair is supported by a driving wheel, a caster, and a lifting mechanism. Even in this case, since the frictional force acts on the lifting mechanism with the floor surface, it is difficult to move even if an external force is applied during transfer.

  In the present invention, a wheelchair lifting mechanism is installed in the vicinity of the caster mounting position of the wheelchair, and a part or front part of the external force acting on the caster and the floor surface at the time of transfer is shared by this lifting mechanism. Since the lifting mechanism is partially connected to the wheelchair body and the end is in contact with the floor surface, the wheelchair is difficult to move due to the frictional force acting on the end and the floor surface. With this mechanism, the user or caregiver can perform a transfer operation with a stable posture during transfer, and the burden on the waist and the like is reduced.

  FIG. 1 is a perspective view of an electric wheelchair 1 shown in Patent Document 1 which is one of wheelchairs to which the present invention is applied. The seat where the user sits consists of a seating surface 3 parallel to the horizontal plane and a backrest 5 that supports the back, and is sandwiched between left and right armrests 7. The seating portion is supported by the right frame 9 and the left frame 11, and both the frames 9 and 11 are fixed to the bottom plate 13. The bottom plate 13 is supported by a caster 15 at the front and left and right by a drive wheel 17 at the rear, and can travel. When the user operates the joystick 19, the electric signal from the joystick 19 moves the drive motor unit 21, and the force moves the drive wheel 17.

  FIG. 2 is a sectional view showing a first embodiment of the present invention. Here, the lifting mechanism is constituted by a rotating lever 23. The rotation lever 23 is installed in a gap between the seating surface 3 and the right frame 7 and between the seating surface 3 and the left frame 9 (see FIGS. 1 and 3). A bearing portion of the rotation center 25 of the rotation lever 23 is not shown, but is fixed to the bottom plate 13 close to the mounting position of the caster 15.

  The lower portion 27 of the rotary lever is below the bottom plate 13, and the upper portion 29 of the rotary lever is an upper portion of the bottom plate 13, and the overall shape is a rod-like body bent into a “<” shape.

  3 to 5 are perspective views for explaining the movement of the rotary lever 23 during transfer. However, users are omitted in these drawings. FIG. 3 shows the position of the rotary lever 23 during normal travel. The rotary lever upper part 29 protrudes in front of the seating part. In this case, a role of protecting the lower limbs of the user from the left and right may be imposed on the rotary lever upper part 29.

  FIG. 4 shows a first stage in which the transfer operation is started. That is, after the electric wheelchair 1 is stopped beside a bed or the like (not shown), the armrest 7 is retracted backward to facilitate transfer. Next, the uppermost portion 31 of the rotating lever is pulled backward, that is, the rotating lever 23 is rotated in the direction of the arrow 33.

  FIG. 5 shows a second stage in which the transfer operation is performed, and shows a state where the rotation lever 23 has been completely turned. Since the lowermost part of the rotating lever is in contact with the floor surface and the upper part 29 of the rotating lever is hidden below the seating surface 3, the transfer operation is not hindered.

  6 to 8 are diagrams for explaining the above operation in more detail. FIG. 6 shows a state during traveling. The lowermost portion 35 of the rotary lever is separated from the floor surface 37, so that it does not interfere with traveling.

  FIG. 7 is a first stage in which the transfer operation corresponding to FIG. 4 is started. The armrest 7 is tilted backward, but the lowermost portion 35 of the rotary lever is separated from the floor surface 37.

  FIG. 8 shows a state of the wheelchair during the transfer operation. Since the lowermost portion 35 of the rotary lever is in contact with the floor surface 37 and lifts the front portion of the wheelchair 1, the caster 15 is in a state of floating from the floor surface 37. Accordingly, the wheelchair 1 is supported by the drive wheel 17 and the rotary lever lower portion 27, and the wheelchair 1 is fixed to the floor surface by the frictional force acting on the lowermost portion 35 of the rotary lever and the floor surface 37.

9 and 10 are diagrams for explaining in detail the shape of the rotating lever 23, particularly the shape of the lowermost portion 35 of the rotating lever. In FIG. 9, a rubber-like body 39 is stretched at the lowermost portion 35 of the rotary lever 23. The rubber-like body 39 functions to increase the coefficient of friction with the floor surface.

  In FIG. 10, a roller 41 is provided in the lowermost portion 35 of the rotation lever 23 instead of the rubber-like body 39. Since the rotation shaft of this roller is fixed, it is easy to rotate in the traveling direction of the wheelchair but difficult to move in the lateral direction. Therefore, the force in the front-rear direction of the wheelchair at the time of transfer is restrained by the brake in the drive wheel 17, and the force in the lateral direction is restrained by the roller 41 and the drive wheel 17. The advantage of providing a roller compared to a rubber-like body is that less force is required for the lifting operation.

  11 and 12 show the second embodiment, and the shape of the rotating lever 23 is different. As can be seen from FIG. 11, the overall bending direction of the rotary lever 23 is opposite to that shown in FIG. Along with this, the rotation direction of the rotary lever for performing the lifting operation is reversed, but the function itself is the same, so the description of the operation is omitted.

  The shape described in FIG. 3 is assumed when the upper part 29 of the rotating lever can be used to protect the user's knees and the like when traveling, and the shape described with reference to FIG. 11 when the upper part 29 of the rotating lever seems to be an obstacle when traveling. The selected shape may be selected.

  The conventional lifting mechanism has been a case where the lifting operation is performed by the caregiver or the user, but FIGS. 13 and 14 show a third embodiment in which the lifting operation is performed by a motor. In FIG. 13, the drive motor 51 has a large gear 53 on the same axis, and the rotational movement of the drive motor 51 rotates the large gear 53 about the vertical axis. The large gear 53 meshes with the small gear 55. A ball screw 57 is provided on the rotation shaft of the small gear 55. The rotational movement of the small gear 55 is the vertical movement of the ball screw 57 in the axial direction, and this vertical movement lifts the end of the lever 61 via the link 59. Since the lever 61 is configured to rotate around the rotation shaft 63, this movement becomes a rotation movement of the lever 61. At the time of transfer, the rotational motion of the motor 51 rotates the lever 61 in the direction of the arrow 65. This figure is a diagram for explaining the principle of movement of each part, and the attachment of the drive motor 51, the bearing of the ball screw 57, and the like are omitted.

  FIG. 14 shows a state in which the caster 15 is lifted by the tip 67 of the lever 61 pushing the floor surface as a result of the rotation. In FIG. 14, the mounting tool for the drive motor 51 is omitted.

  In FIG. 13 and FIG. 14, the rotational motion of the drive motor is converted into a linear motion by a ball screw, and the rotational motion of the lever is made via the link mechanism. However, the mechanism is not limited to this mechanism. Various deformations are conceivable, such as converting motion to linear motion using racks and pinions. Furthermore, although the case where the drive motor is used as the drive source has been described, the present invention is not limited to this, and actuators such as pneumatic pressure and hydraulic pressure may be used.

  In the description so far, the lifting mechanism lifts the caster completely, but the present invention is not limited to this. That is, the lifting mechanism may reduce the force that the caster receives from the floor surface. That is, the reduced remaining force is shared by the lifting mechanism, and a frictional force is generated by the force at a position where the lifting mechanism and the floor surface are in contact with each other. This frictional force acts in the opposite direction to the external force parallel to the floor surface, making the wheelchair difficult to move.

  When the roller is provided at the contact portion with the floor surface of the lifting mechanism, since the rotation direction of the roller is the front-rear direction of the wheelchair as described above, the front-rear restraint cannot be expected in this case. However, the frictional force works against the external force from the side of the wheelchair, making it difficult for the wheelchair to move.

  In the above description, the lifting mechanism is described as being provided symmetrically on the left and right of the seating portion, but it may be provided only on one side. Even in this case, the wheelchair becomes much harder to move than in the case of only the casters, and stable transfer is possible. Of course, it is more effective to install them on the left and right, but the price increases.

  In the above description, the caster is on the front side of the electric wheelchair and the driving wheel is on the rear side, but the opposite case may be used. Also in this case, since it is necessary to provide the lifting mechanism near the caster, it is necessary to devise the shape when the lifting mechanism is realized by a rotating lever.

  In the above description, the case where the present invention is applied to an electric wheelchair has been described. However, the present invention is not limited to this, and needless to say, the present invention may be applied to an ordinary manual or rowing wheelchair. In Claim 1, although expressed as a drive wheel, the wheel which transmits the force of a hand corresponds to a drive wheel in this case.

  As described above, in a wheelchair configured to be movable with a plurality of driving wheels and casters, a mechanism for bearing a part or all of the force exerted on the floor surface by the casters when the wheelchair user is transferred is added near the casters. I explained that. The mechanism that bears part or all of the force exerted on the floor by the caster is a lifting mechanism that is installed near the bottom of the main body of the wheelchair and lifts the wheelchair so as to reduce the force of the wheelchair caster pushing the floor I explained that.

The perspective view of the electric wheelchair suitable for applying this invention 1st Example of applying the present invention of a conventional electric wheelchair The perspective view for demonstrating the operation | movement of this invention The perspective view for demonstrating the operation | movement of this invention The perspective view for demonstrating the operation | movement of this invention Side view showing the operation of the present invention in detail Side view showing the operation of the present invention in detail Side view showing the operation of the present invention in detail Detailed view of rotary lever used in the first embodiment of the present invention Another detailed view of the rotary lever used in the first embodiment of the present invention Second embodiment of the present invention (during traveling) Second embodiment of the present invention (during transfer) Third embodiment of the present invention (running) Third embodiment of the present invention (during transfer)

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electric wheelchair 3 Seating surface 5 Backrest part 7 Armrest 9 Right frame 11 Left frame 13 Bottom plate 15 Caster 17 Drive wheel 19 Joystick 21 Drive motor part 23 Rotation lever 25 Rotation center 27 Rotation lever lower part 29 Rotation lever upper part 31 Rotation lever uppermost part 33 Arrow 35 Bottom of rotation lever 37 Floor 39 Rubber-like body 41 Roller 51 Drive motor 53 Large gear 55 Small gear 57 Ball screw 59 Link 61 Lever 63 Rotating shaft 65 Arrow 67 Lever tip

Claims (2)

In a wheelchair configured to be movable by a plurality of drive wheels and casters, a mechanism for bearing part or all of the force exerted on the floor by the casters when the wheelchair user is transferred is added near the casters. Characteristic wheelchair The mechanism that bears part or all of the force exerted on the floor surface by the caster according to claim 1 is installed near the bottom of the main body of the wheelchair so as to reduce the force of the wheelchair caster pushing the floor surface. A wheelchair characterized by a lifting mechanism for lifting a wheelchair

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