JP7750750B2 - wheelchair - Google Patents

Description

The present disclosure relates to a wheelchair having a seat section and multiple wheels.

For example, in the wheelchair described in Patent Document 1, the footrest is configured to be displaceable in the vertical direction relative to the seat section via an arm.

JP 2016-20280 A

A footrest is a part that supports the legs of a seated person. Therefore, this disclosure discloses an example of a wheelchair that can prevent the footrest from displacing too much when, for example, the weight of a seated person acts on the footrest.

A wheelchair equipped with a seat portion (2) on which a user can sit and multiple wheels (3A-3D) attached to the seat portion (2) preferably has at least one of the following components:

In other words, the components preferably include a footrest (4A) for supporting the legs of a seated occupant; a support arm (51A) that supports the footrest (4A) so that it can be moved between an in-use position and a retracted position offset from the in-use position, the support arm (51A) being swingably connected to the chair portion (2); a first link (52) that transmits an operating force for swinging the support arm (51A) to the support arm (51A), the first link (52) being swingably connected to the chair portion (2); a second link (53) having one end swingably connected to the first link (52) and the other end swingably connected to the support arm (51A); and a restriction portion (58) that restricts the second connection center (O2) from moving away from the seat line (Lo) by more than a predetermined distance when a load is applied to the footrest (4A) when the footrest (4A) is in the in-use position.

Furthermore, when the second connection center (O2) moves away from the holding line (Lo), the footrest (4A) is configured to displace toward the retracted position, and when the footrest (4A) is in the use position, the second connection center (O2) is located in an area on one side of the holding line (Lo) (hereinafter referred to as the use area), and when the footrest (4A) is in the retracted position, the second connection center (O2) is located in an area on the other side of the holding line (Lo).

The first connection center (O1) refers to the connection center between the first link (52) and the seat section (2). The second connection center (O2) refers to the connection center between the first link (52) and the second link (53). The third connection center (O3) refers to the connection center between the second link (53) and the support arm (51A). The imaginary line (Lo) refers to the imaginary line that passes through the first connection center (O1) and the third connection center (O3).

As a result, in this wheelchair, when the second connecting center (O2) is located on the tilt line (Lo), that is, when the second connecting center (O2) coincides with the tilt point (dead point), the footrest (4A) is in the position furthest from the retracted position (hereinafter referred to as the furthest position). When the second connecting center (O2) moves away from the tilt line (Lo) so as to enter the use area, the footrest (4A) is in the use position.

In other words, the use position of the wheelchair is shifted from the farthest position toward the retracted position. Therefore, when a large load acts on the footrest (4A) while it is in the use position, the second connection center (O2) moves away from the center line (Lo) and the footrest (4A) moves closer to the retracted position.

In response to this, the wheelchair is equipped with a restriction section (58) that restricts the second connection center (O2) from moving away from the center line (Lo) beyond a predetermined distance.

As a result, even if a large load acts on the footrest (4A) when it is in the use position, the footrest (4A) can be prevented from shifting significantly from the use position toward the retracted position. Consequently, this wheelchair prevents the footrest (4A) from being displaced significantly when the weight of the seated occupant acts on the footrest (4A).

Incidentally, the symbols in parentheses above are examples showing the correspondence with the specific configurations, etc. described in the embodiments described below, and the present disclosure is not limited to the specific configurations, etc. indicated by the symbols in parentheses above.

1 is a diagram showing a wheelchair according to a first embodiment. FIG. 1 is a diagram showing a wheelchair according to a first embodiment. FIG. 1 is a diagram showing a wheelchair according to a first embodiment. FIG. FIG. FIG. FIG. FIG. 1 is a side view of a wheelchair according to a first embodiment. FIG. 1 is a side view of a wheelchair according to a first embodiment. 9A to 9C are explanatory diagrams of the operation of the support mechanism. FIG. 10 is a diagram showing a first operating lever according to a second embodiment. 10A and 10B are diagrams illustrating the structure of a first operating lever according to a second embodiment.

The following "Embodiments of the Invention" are examples of embodiments within the technical scope of this disclosure. In other words, the invention-specific matters set forth in the claims are not limited to the specific configurations and structures shown in the following embodiments.

Note that arrows and diagonal lines indicating directions in each figure are included to facilitate understanding of the relationships between the figures and the shapes of each component or part. Therefore, the invention presented in this disclosure is not limited to the directions indicated in each figure. Diagonal lines do not necessarily indicate cross-sectional views.

At least one component or part that is described with a reference number is provided, unless otherwise specified, such as "one." In other words, unless otherwise specified, such as "one," two or more components may be provided. The wheelchair shown in this disclosure includes at least the components, such as components or parts, that are described with a reference number, as well as the structural parts shown in the drawings.

(First embodiment)
<1. Wheelchair Overview>
In this embodiment, an example of a wheelchair according to the present disclosure is applied to a foldable wheelchair. As shown in Figure 1, the wheelchair 1 includes at least a seat section 2, a plurality of wheels 3A to 3D, two footrests 4A and 4B, and two support mechanisms 5A and 5B.

The seat section 2 is the area where a user can sit. The seat section 2 is composed of a frame, seat cloth 2A, etc. The frame is made up of multiple metal pipes. The seat cloth 2A is attached to the frame to form the seat surface, such as the seating surface.

Multiple wheels 3A-3D are attached to the frame and support the chair portion 2 for movement. Wheels 3A and 3B form the drive wheels and support much of the load acting on the chair portion 2. Wheels 3C and 3D maintain the position of the chair portion 2 and assist in steering (changing direction) the wheelchair 1.

The footrests 4A and 4B are footrests for supporting the legs (soles of the feet in this embodiment) of a seated person. The footrest 4A is supported by a support mechanism 5A so as to be displaceable. The footrest 4B is supported by a support mechanism 5B so as to be displaceable.

Specifically, the support mechanisms 5A and 5B support the footrests 4A and 4B, respectively, so that they can be displaced between a use position (see Figure 2) and a retracted position (Figure 3) that is offset from the use position. The use position in this embodiment is located above the retracted position. The retracted position in this embodiment is a position where the footrests 4A and 4B can come into contact with the floor or ground.

Note that the footrests 4A, 4B and the support mechanisms 5A, 5B are configured to be approximately symmetrical with respect to the center of the wheelchair 1 in the left-right direction. The support mechanisms 5A and 5B can operate independently of each other. The following explanation mainly focuses on the support mechanism 5A.

<2. Support mechanism>
2.1 Configuration of the support mechanism
As shown in FIG. 4, the support mechanism 5A is configured to have at least one (two in this embodiment) support arm 51A, 51B, a first link 52, a second link 53, a base portion 54, etc.

The base 54 is attached to the frame of the chair 2 and supports the load acting on the support arms 51A and 51B. The support arms 51A and 51B are members that support the footrest 4A so that it can be displaced between the use position and the retracted position, and are swingably connected to the base 54.

Specifically, one end of the support arm 51A (hereinafter referred to as the first support arm 51A) is rotatably connected to the base 54. The other end of the first support arm 51A is rotatably connected to the front shaft 4C of the footrest 4A.

One end of the support arm 51B (hereinafter referred to as the second support arm 51B) is rotatably connected to the base 54 at a position shifted rearward and downward from the first support arm 51A. The other end of the second support arm 51B is rotatably connected to the rear end shaft 4D of the footrest 4A.

As a result, the base 54, first support arm 51A, second support arm 51B, and footrest 4A form a four-joint link mechanism. Therefore, when at least one of the first support arm 51A and the second support arm 51B swings, the footrest 4A swings and displaces accordingly (see Figures 4 to 6).

The first link 52 is a member that transmits an operating force to the drive arm to swing and displace either the first support arm 51A or the second support arm 51B (hereinafter, this support arm will be referred to as the drive arm). Note that the drive arm in this embodiment is the first support arm 51A.

One end of the first link 52 is swingably connected to the chair portion 2 (in this embodiment, the base portion 54). The second link 53 is a member swingably connected to the first link 52 at one end and to the drive arm, i.e., the first support arm 51A, at the other end.

An operating link 55 is provided on the opposite side of the first link 52 across the connection point with the second link 53. The operating link 55 is a member for inputting an operating force to the first link 52. In other words, the first link 52 functions as a drive link. In this embodiment, the operating link 55 and the first link 52 swing together.

As shown in FIG. 7, a first operating lever 56 and a second operating lever 57 are directly or indirectly connected to the operating link 55. The first operating lever 56 and the second operating lever 57 are members operated by the user.

The first operating lever 56 is located on the front side of the seat section 2 (in this embodiment, forward of the wheels 3A). The second operating lever 57 is located on the rear side of the seat section 2. When either operating lever is operated, an operating force is input to the first link 52.

In this embodiment, the first operating lever 56 is directly fixed to the operating link 55 with a fastener such as a bolt 56A (see Figure 2). Therefore, the user can easily attach or detach the first operating lever 56 to or from the operating link 55 by attaching or detaching the bolt 56A (see Figure 8).

As shown in Figure 8, the second operating lever 57 in this embodiment is indirectly connected to the operating link 55 via a push-pull wire device. Note that even when the first operating lever 56 is detached, the user can still operate the first link 52 with the second operating lever 57.

2.2 Details of the support mechanism
<Definition of Terms (See FIG. 9A)>
First connection center O1: connection center between the first link 52 and the seat portion 2 Second connection center O2: connection center between the first link 52 and the second link Third connection center O3: connection center between the second link and the support arm 51A Virtual line Lo: virtual straight line passing through the first connection center O1 and the third connection center O3 <Operation of support mechanism>
When the drive link, i.e., the first link 52, swings, the first support arm 51A swings as shown in Figures 9A to 9C . At this time, when the second connection center O2 moves away from the tilt line Lo, the footrest 4A is displaced toward the retracted position. Note that when the second connection center O2 moves toward the retracted position relative to the tilt line Lo, i.e., downward relative to the tilt line Lo, the footrest 4A is also displaced toward the retracted position.

When the footrest 4A is in the use position, the second connection center O2 is located in an area on one side (in this embodiment, the upper side) of the line of sight Lo, i.e., the use area, and when the footrest 4A is in the retracted position, the second connection center O2 is located in an area on the other side (in this embodiment, the lower side) of the line of sight Lo.

However, when a load acts on the footrest 4A while it is in the use position, the second connection center O2 attempts to displace from its current position in a direction away from the target line Lo (upward in this embodiment).

In other words, when the footrest 4A is in the use position, the second connection center O2 is located in an area on one side of the line of inclination Lo. When a load is applied to the footrest 4A, the second connection center O2 attempts to move further away from the line of inclination Lo, causing the footrest 4A to displace toward the retracted position.

To address this issue, the support mechanism 5A according to this embodiment is provided with a restricting portion 58. When a load acts on the footrest 4A while the footrest 4A is in the use position, the restricting portion 58 restricts the second connection center O2 from moving away from the center line Lo by more than a predetermined distance.

Specifically, the restricting portion 58 contacts at least one of the first link 52 and the second link 53 (in this embodiment, the first link 52), thereby restricting the second connection center O2 from moving away from the center line Lo by more than a predetermined distance.

The restricting portion 58 according to this embodiment is provided on the first support arm 51A at the connection point (see 9A) with the base portion 54. The use position according to this embodiment is a state in which the restricting portion 58 and the first link 52 are in contact with each other, that is, a position in which the displacement of the first link 52 is restricted.

Incidentally, when the second connection center O2 is in the neutral position, that is, when the second connection center O2 coincides with the neutral point (dead center) as shown in Figure 9 (B), the footrest 4A is in its highest position. Therefore, the use position in this embodiment is slightly shifted toward the retracted position from this highest position.

3. Features of the wheelchair according to this embodiment (see FIGS. 9A to 9C)
In the wheelchair 1 according to this embodiment, when the second connecting center O2 is located on the tilt line Lo, that is, when the second connecting center O2 coincides with the tilt point, the footrest 4A is in the position furthest from the retracted position (hereinafter referred to as the furthest position). When the second connecting center O2 moves away from the tilt line Lo so as to enter the use area, the footrest 4A is in the use position.

In other words, the use position of the wheelchair 1 is shifted from the farthest position toward the retracted position. Therefore, when a large load acts on the footrest 4A while it is in the use position, the second connection center O2 moves away from the center line Lo, and the footrest 4A moves closer to the retracted position.

In response to this, the wheelchair 1 is equipped with a restriction section 58 that restricts the second connection center O2 from moving away from the center line Lo by more than a predetermined distance.

As a result, even if a large load acts on the footrest 4A when it is in the use position, the footrest 4A can be prevented from shifting significantly from the use position toward the retracted position. Consequently, the wheelchair 1 prevents the footrest 4A from being displaced significantly when the weight of the seated occupant acts on the footrest 4A.

In this embodiment, the displacement of the footrest 4A is not restricted by restricting the operation of the first operating lever 56 or the second operating lever 57 (wire device). Therefore, compared to a configuration in which a restricting mechanism is provided on the wire device, for example, the wheelchair 1 is superior in terms of safety and reliability.

By contacting at least one of the first link 52 and the second link 53, the restricting portion 58 restricts the second connection center O2 from moving away from the center line Lo by more than a predetermined distance. This ensures that the wheelchair 1 restricts the footrest 4A from being displaced too far.

A second operating lever 57 for operating the first link 52 is provided on the rear side of the chair portion 2. This allows an assistant assisting from behind the wheelchair 1 to displace the footrest 4A without having to move to the front side of the wheelchair 1.

The first operating lever 56, located on the front side of the chair portion 2, is detachable. This allows the first operating lever 56 to be removed when it is not needed.

Second Embodiment
In this embodiment, as shown in Fig. 10, a telescopic operating lever 59 is used as the first operating lever 56. Specifically, as shown in Fig. 11, the operating lever 59 is configured to include an outer pipe 59A, an inner pipe 59B, and a locking device 59C.

The outer pipe 59A is fixed to the operating link 55. The inner pipe 59B is slidably inserted into the outer pipe 59A. The locking device 59C is provided on the outer pipe 59A and restricts sliding displacement of the inner pipe 59B relative to the outer pipe 59A.

That is, the locking device 59C includes a plunger (a steel ball in this embodiment) 59E, a spring 59F, and a holder portion 59G. The plunger 59E is a member that can fit into a hole or recess (hole 59D in this embodiment) provided on the outer periphery of the inner pipe 59B.

The spring 59F is an elastic body that presses the plunger 59E toward the inner pipe. The holder portion 59G holds the plunger 59E in a displaceable manner. As a result, when the inner pipe 59B slides and the position of the plunger 59E coincides with the position of the hole 59D, the plunger 59E fits into the hole 59D, restricting the displacement of the inner pipe 59B.

When the force sliding the inner pipe 59B increases, the plunger 59E disengages from the hole 59D, reducing the force restricting the sliding displacement of the inner pipe 59B, allowing the inner pipe 59B to slide easily.

The inner periphery of the outer pipe 59A and the outer periphery of the inner pipe 59B are provided with ridges that fit together slidably. This prevents the inner pipe 59B from rotating around the central axis of the outer pipe 59B. This allows the plunger 59E to fit securely into the hole 59D when the inner pipe 59B slides.

In this embodiment, when the footrests 4A, 4B are in their retracted positions (see Figure 3), i.e., when the user is getting on or off the chair portion 2, the first operating lever 56 (hereinafter referred to as operating lever 59) is positioned further forward than in the use position.

As a result, when a user gets on or off the chair portion 2, the operating lever 59 may become an obstacle, making it difficult for the user to get on or off. However, in this embodiment, the operating lever 59 is extendable, so the user can retract the operating lever 59 when getting on or off.

This in turn prevents the operating lever 59 from becoming an obstacle when getting on and off the vehicle. Furthermore, if the operating lever 59 is in an extended state when the user operates the operating lever 59, the operating force required to operate the operating lever 59 is reduced.

In other words, this embodiment can prevent the operating force required to operate the first operating lever 56 (operating lever 59) from becoming excessively large while minimizing deterioration in ease of getting in and out of the vehicle.

(Other embodiments)
In the above-described embodiment, the second operating lever 57 is connected to the operating link 55 via a push-pull wire type wire device. However, the present disclosure is not limited to this. That is, the present disclosure may be, for example, a link device in which the second operating lever 57 is configured with a connecting rod or the like, a wire device having two pull wires, or a wire device having one pull wire and a return spring.

In the above-described embodiment, the operating link 55 is configured to receive a manual operating force from the first operating lever 56 or the second operating lever 57. However, the present disclosure is not limited to this. In other words, the present disclosure may also be configured to receive an operating force from an electric actuator such as an electric motor.

In the above-described embodiment, when the second connection center O2 is displaced downward with respect to the tilt line Lo, the footrest 4A is displaced toward the retracted position. However, the present disclosure is not limited to this. That is, the present disclosure may be configured, for example, such that when the second connection center O2 is displaced downward with respect to the tilt line Lo, the footrest 4A is displaced toward the retracted position.

In the above-described embodiment, the restricting portion 58 restricts the separation of the second connection center O2 by contacting at least one of the first link 52 and the second link 53. However, the present disclosure is not limited to this. That is, the present disclosure may be configured such that, for example, an abutment portion is provided on the first link 52 or the second link 53, and the restricting portion 58 contacts the abutment portion.

In the above-described embodiment, the restricting portion 58 is provided at the base portion 54 of the first support arm 51A. However, the present disclosure is not limited to this. In other words, the present disclosure may also be configured such that the restricting portion 58 is provided at the base portion 54, for example.

The support mechanisms 5A, 5B in the above-described embodiments are configured to support the footrests 4A, 4B so that they can be displaced in the vertical direction. However, the present disclosure is not limited to this. In other words, the present disclosure may also be directed to support mechanisms 5A, 5B that support the footrests 4A, 4B so that they can be displaced in the horizontal direction, for example.

Furthermore, the present disclosure is not limited to the above-described embodiments, as long as it conforms to the spirit of the disclosure described in the above-described embodiments. Therefore, the present disclosure may be a configuration in which at least two of the above-described embodiments are combined, or a configuration in which any of the constituent elements shown in the drawings or those described with reference numerals in the above-described embodiments are eliminated.

REFERENCE SIGNS LIST 1... wheelchair 2... chair section 3A to 3D... wheels 4A, 4B... footrests 5A, 5B... support mechanism 13C... first operating lever 51A, 51B... support arm 52... first link 53... second link 54... base section 55... operating link 56... first operating lever 57... second operating lever 58... restricting section

Claims (4)

A wheelchair having a seat portion on which a user can sit and a plurality of wheels provided on the seat portion,
a footrest for supporting the soles of the feet of a seated person;
a support arm that supports the footrest so that it can be displaced between a use position and a retracted position that is a position shifted from the use position and in which the footrest can be in contact with the floor or the ground , the support arm being swingably connected to the chair portion;
a first link that transmits an operating force for swinging and displacing the support arm to the support arm, the first link being swingably connected to the chair portion;
a second link having one end pivotally connected to the first link and the other end pivotally connected to the support arm,
When a connection center between the first link and the chair portion is defined as a first connection center, a connection center between the first link and the second link is defined as a second connection center, a connection center between the second link and the support arm is defined as a third connection center, and an imaginary line passing through the first connection center and the third connection center is defined as a hypothetical line,
When the second connection center moves away from the center line, the footrest is displaced toward the retracted position,
When the footrest is in the use position, the second connection center is located in an area on one side of the line of sight, and when the footrest is in the retracted position, the second connection center is located in an area on the other side of the line of sight,
The wheelchair further includes a regulating portion that, when the footrest is in the use position and a load is applied to the footrest, prevents the second connection center from moving away from the center line by more than a predetermined distance, the regulating portion being provided on the support arm and contacting at least one of the first link and the second link . 2. The wheelchair according to claim 1 , wherein an operating section for operating the first link is provided on the rear side of the seat section. 3. The wheelchair according to claim 1, wherein a detachable operating lever for operating the first link is provided on the front side of the seat portion. 3. The wheelchair according to claim 1, wherein a telescopic operating lever for operating the first link is provided on the front side of the chair portion.