WHEELCHAIR

To facilitate attachment of a seat and suppress rattling of the attached seat, a seat frame is provided with a frame abutment section that abuts a side frame from one side in a left-right direction; an abutment member that abuts the side frame from the other side in the left-right direction; and a shaft member that supports the abutment member in a manner to allow rotation thereof about an axis extending in a body front-rear direction with respect to a body portion of the seat frame. The side frame includes a convex section that protrudes upward, the convex section pressing the abutment member from below during attachment of the seat frame and thereby causing the abutment member to rotate in a direction in which a portion of the abutment member below the axis abuts the side frame.

TECHNICAL FIELD

The present disclosure relates to a folding wheelchair that is configured to be foldable.

BACKGROUND ART

In general, folding wheelchairs configured to be foldable when not in use have been known (for example, see JP2022-114838A). In the wheelchair disclosed in JP2022-114838A, a left support arm is rotatably coupled to a left side frame, to which a left drive wheel is attached, and a right support arm is rotatably coupled to a right side frame, to which a right drive wheel is attached. When the wheelchair is unfolded from a folded state, the left support arm and the right support arm rotate rearward. In this way, a distance between the left side frame and the right side frame is reduced, and thus the wheelchair can be made compact.

In the wheelchair disclosed in JP2022-114838A, a seat before being folded has to be detached from the left side frame and the right side frame. Thus, the seat is attachable/detachable to/from both of the side frames. More specifically, pins, each of which protrudes forward from a seat frame, are inserted in insertion holes formed in both of the side frames. In this way, the seat is fixed to both of the side frames. Meanwhile, the seat can be detached from both of the side frames by retracting the pins.

SUMMARY

However, as in JP2022-114838A, in the case where such a structure is adopted that the pins, each of which advances from the seat frame, are inserted in the insertion holes of the side frames, an operation to switch the pins from a retracted state to an advanced state has to be performed when the seat is attached. Thus, time and effort are required to attach the seat.

In addition, the pins cannot be inserted smoothly unless an outer diameter of each of the pins is set to be smaller than an inner diameter of the insertion hole. However, when the outer diameter of each of the pins is set to be smaller than the inner diameter of the insertion hole, such a problem occurs that the seat is likely to rattle against the side frames.

The present disclosure has been made in view of such a point, and accordingly allows easy attachment of a seat and to suppress rattling of the attached seat.

In order to achieve the above purpose, a first aspect of the present disclosure can assume a folding wheelchair including a seat on which a wheelchair user can be seated. The wheelchair includes: a left side frame that axially supports a drive wheel on a left side of a body; a right side frame that axially supports a drive wheel on a right side of the body; and a support arm that couples the left side frame and the right side frame and is foldable. The seat has a seat frame that is configured to be attachable to the left side frame and the right side frame from above. The seat frame is provided with a frame abutment section that abuts at least one side frame of the left side frame and the right side frame from one side in a left-right direction; an abutment member that abuts the one of the side frames from the other side in the left-right direction; and a shaft member that supports the abutment member in a manner to allow rotation of the abutment member about an axis extending in a body front-rear direction with respect to a body portion of the seat frame.

The one of the side frames is provided with a convex section in a manner to protrude upward, the convex section pressing the abutment member from below during attachment of the seat frame and thereby causing the abutment member to rotate in a direction in which a portion of the abutment member below the axis abuts the one of the side frames.

With this configuration, when the seat frame is attached to the side frame, the convex section of the side frame presses the abutment member of the seat frame from below. Since the abutment member that is pressed from below is supported to be rotatable about the axis extending in the body front-rear direction with respect to the body portion of the seat frame. Thus, the abutment member rotates in the direction in which the lower portion of the abutment member abuts the side frame. As a result, the frame abutment section and the abutment member of the seat frame hold the side frame in the left-right direction. Accordingly, there is no need to switch a pin from a retracted state to an advanced state as in the related art, the attachment of the seat is facilitated, a clearance is unlikely to be provided between the seat frame and the side frame, and rattling of the seat is thereby suppressed.

The convex section according to a second aspect of the present disclosure is disposed to press a portion of the abutment member on one side in the left-right direction of the axis during the attachment of the seat frame.

With this configuration, since the portion pressing the abutment member in the convex portion is the portion on the one side in the left-right direction rather than the axis. Thus, a downward pressing force by the convex section is applied such that the portion of the abutment member below the axis abuts the side frame from the other side in the left-right direction. In this way, the abutment member can reliably abut the side frame.

The seat frame according to a third aspect of the present disclosure is provided with an urging member that constantly urges the abutment member in a direction away from the frame abutment section.

With this configuration, in a state where the seat is not attached, the abutment member rotates in the direction away from the side frame by the urging force generated by the urging member. Thus, when the seat is attached, the seat frame can easily be inserted between the frame abutment section and the abutment member.

The abutment member according to a fourth aspect of the present disclosure may extend to a position below the one of the side frames along a side surface of the one of the side frames. In this case, a lower end portion of the abutment member can be formed with a protruding section that is disposed to protrude to one side in the left-right direction and oppose a lower surface of the one of the side frames.

With this configuration, when the side frame, which is held by the frame abutment section and the abutment member, moves downward to be removed from the position between the frame abutment section and the abutment member in the attachment state of the seat, the protruding section of the abutment member is disposed to oppose the lower surface of the side frame. Thus, the lower surface of the side frame contacts the protruding section. This ensures that the side frame is not unexpectedly removed from the position between the frame abutment section and the abutment member.

In a fifth aspect of the present disclosure, a predetermined space is provided between the protruding section of the abutment member and the lower surface of the one of the side frames.

With this configuration, the predetermined space is provided between the protruding section of the abutment member and the lower surface of the side frame in the state where the seat is attached. Thus, when it is attempted to detach the seat, the seat frame can be lifted with respect to the side frame by the space. As a result, the abutment member rotates in the direction away from the side frame by the urging force of the urging member. Thus, the seat frame can easily be detached from the side frame.

The urging member according to a sixth aspect of the present disclosure can be formed of a coil spring that is disposed between the frame abutment section and the abutment member in a manner that a compression direction is oriented in the left-right direction. In this case, an intermediate portion of the convex section in the body front-rear direction can be formed with a notched section in which an intermediate portion of the coil spring in the left-right direction can be accommodated.

With this configuration, the abutment member can be urged in a desired direction by a simple configuration of using the coil spring that can be compressed or extended in the left-right direction. In this case, it is possible to avoid interference between the convex section of the side frame and the coil spring.

As it has been described so far, when the seat is attached, the side frame is held in the left-right direction by causing the rotation of the abutment member. Therefore, it is possible to easily attach the seat and suppress rattling of the attached seat.

DETAILED DESCRIPTION

A detailed description will hereinafter be made on an embodiment of the present disclosure with reference to the drawings. The following description on a preferred embodiment is essentially and merely illustrative and thus has no intention to limit the present disclosure, application subjects thereof, and application thereof.

FIG.1is a perspective view in which a wheelchair1according to the embodiment of the present disclosure is seen diagonally upward from the front. As illustrated inFIG.2andFIG.3, this wheelchair1is a wheelchair configured that a seat3can be detached from a wheelchair body2without the need for a tool.FIG.4is a left side view of the seat3that is detached from the wheelchair body2. As illustrated inFIG.5andFIG.6, the wheelchair body2in a detachment state of the seat3is configured to be foldable. Thus, the wheelchair1according to this embodiment is a folding wheelchair on which a wheelchair user can be seated.

In the description of this embodiment, an advancing direction of the wheelchair1during forward travel is simply referred to as the front, and a front side of the wheelchair1corresponds to a front side of the wheelchair user (not illustrated) who is seated on the wheelchair1. In addition, an advancing direction of the wheelchair1during rearward travel is simply referred to as the rear, and a rear side of the wheelchair1corresponds to a rear side of the wheelchair user who is seated on the wheelchair1. A front-rear direction of the wheelchair1is also a longitudinal direction of a body. A left side of the wheelchair user who is seated on the wheelchair1is a left side of the body of the wheelchair1and is simply referred to as the left. Furthermore, a right side of the wheelchair user who is seated on the wheelchair1is a right side of the body of the wheelchair1and is simply referred to as the right. A left-right direction of the wheelchair1is a width direction of the body and is also referred to as a body width direction. An “upper side” of the wheelchair1is a side that becomes the upper side when the wheelchair1in a seating position is placed on a horizontal surface, and a “lower side” of the wheelchair1is a side that becomes the lower side when the wheelchair1in the seating position is placed on the horizontal surface.

Configuration of Wheelchair Body

As illustrated inFIG.1,FIG.2, and the like, the wheelchair body2includes left and right drive wheels10,11, left and right casters12,13, left and right side frames20,30, upper and lower support arms40,50, and a footrest60. The left drive wheel10is axially supported on the left side frame20, and the right drive wheel11is axially supported on the right side frame30. In addition, the left side frame20and the right side frame30are coupled by the upper support arm40and the lower support arm50. By folding the upper support arm40, the lower support arm50, and the footrest60, as illustrated inFIG.5andFIG.6, the wheelchair1can be brought into a folded state.

The drive wheels10,11are large-diameter wheels that are hand-held and rotated forward or rearward by the wheelchair user who is seated on the seat3, and can also be referred to as drive rear wheels as being provided on a rear side of the wheelchair body2. Although structures of the drive wheels10,11are not particularly limited, in this embodiment, the drive wheels10,11are structured that rubber tires10b,11bare respectively attached to wheels10a,11a, each of which is molded of carbon fiber-reinforced plastics (CFRP). Hand rims10c,11cthat are hand-held by the wheelchair user during driving are respectively provided on outer sides of the wheels10a,11ain the body width direction. Although not illustrated, the wheelchair1is provided with a brake. The brake is configured to be manually operable by the wheelchair user who is seated on the seat3. More specifically, the brake generates a braking force by contacting the tires10b,11b.Such a brake has been well known conventionally.

The casters12,13are wheels for changing the advancing direction of the wheelchair1and have smaller diameters than the drive wheels10,11. Since the casters12,13are provided on the front side of the wheelchair body2, the casters12,13can also be referred to as front wheels for changing the advancing direction.

Configurations of Side Frames

As illustrated inFIG.2, the left side frame20includes an upper frame section21that extends in the front-rear direction and a caster support section22.FIG.7illustrates the left side frame20when the wheelchair1is placed on the horizontal surface. As illustrated inFIG.7, the upper frame section21is gently inclined upward to the front. An inclination angle of the upper frame section21may not be the illustrated angle and may be horizontal. The upper frame section21and the caster support section22are integrally molded of the CFRP. Thus, the left side frame20is configured as a single component. Here, the left side frame20may be formed of a metal material or may be formed by joining plural components.

A rear end portion of the upper frame section21is formed with an axle insertion hole21ain which a right portion of an axle10d(illustrated inFIG.1) provided to the left drive wheel10is fixedly inserted. In a state where the right portion of the axle10dis fixed to the rear end portion of the upper frame section21, the left drive wheel10is axially supported on the left side frame20in a manner to be rotatable about an axis extending in the left-right direction.

A left seat frame accommodation section21bin a concave shape is formed in a right portion of the upper frame section21. In the left seat frame accommodation section21b,a rear portion of a left frame section93(indicated by an imaginary line) provided to the seat3is accommodated. In a portion of the upper frame section21other than the rear end portion, the left seat frame accommodation section21bis formed continuously in the front-rear direction. The left seat frame accommodation section21bis opened upward and rightward, is also opened forward, and can thereby accommodate the rear portion of the left frame section93from above.

As indicated by the imaginary line inFIG.7, a front portion of the left frame section93is disposed to protrude forward from the left seat frame accommodation section21b.The upper frame section21is provided with a seat support plate section23for supporting an intermediate portion of the left frame section93in the front-rear direction from below. The seat support plate section23has an elongated plate shape that extends forward, and constitutes a part of the left side frame20. A front end portion of the seat support plate section23is located behind a front end portion of the left frame section93. A concave section23ais provided on a right surface (an inner surface in the body width direction) of an intermediate portion of the seat support plate section23in the front-rear direction.

The left side frame20has an arm coupling member24. The arm coupling member24is a member that is fixed to a right surface (a surface located on the inner side in the body width direction) of an intermediate portion of the left side frame20in the front-rear direction and to which left end portions of the upper support arm40and the lower support arm50are coupled. An upper protruding plate section24athat extends in an up-down direction is provided to an upper portion of the arm coupling member24in a manner to protrude rightward. The upper protruding plate section24ais formed with an upper through hole24bthat penetrates the upper protruding plate section24ain the front-rear direction. A lower protruding plate section24cthat extends in the up-down direction is provided to a lower portion of the arm coupling member24in a manner to protrude rightward. The lower protruding plate section24cis positioned behind the upper protruding plate section24a.The lower protruding plate section24cis formed with a lower through hole24dthat penetrates the lower protruding plate section24cin the front-rear direction.

The caster support section22is formed to extend forward and is lowered toward a front end. A caster attachment section22ais provided to a front end portion of the caster support section22in a manner to protrude downward. To the caster attachment section22a,the left caster12is attached to be turnable about an axis that extends in the up-down direction. Furthermore, a footrest support section22bthat supports the footrest60described below is provided to the front end portion of the caster support section22in a manner to protrude downward. As illustrated inFIG.3, the footrest support section22bis located on the right side (the inner side in the body width direction) of the caster attachment section22a.

The right side frame30has a shape that is bilaterally symmetrical to the left side frame20. More specifically, as illustrated inFIG.8, the right side frame30includes an upper frame section31and a caster support section32.

A rear end portion of the upper frame section31of the right side frame30is formed with an axle insertion hole31ain which a left portion of an axle11d(illustrated inFIG.11) provided to the right drive wheel11is fixedly inserted. In a state where the left portion of the axle11dis fixed to the rear end portion of the upper frame section31, the right drive wheel11is axially supported on the right side frame30in a manner to be rotatable about an axis extending in the left-right direction.

A right seat frame accommodation section31bin a concave shape is formed in a left portion of the upper frame section31of the right side frame30. In the right seat frame accommodation section31b,a rear portion of a right frame section94(indicated by an imaginary line) provided to the seat3is accommodated. In a portion of the upper frame section31other than the rear end portion, the right seat frame accommodation section31bis formed continuously in the front-rear direction. The right seat frame accommodation section31bis opened upward and leftward, is also opened forward, and can thereby accommodate the rear portion of the right frame section94from above.

As indicated by the imaginary line inFIG.8, a front portion of the right frame section94is disposed to protrude forward from the right seat frame accommodation section31b.The upper frame section31is provided with a seat support plate section33for supporting an intermediate portion of the right frame section94in the front-rear direction from below. The seat support plate section33has an elongated plate shape that extends forward, and constitutes a part of the right side frame30. A front end portion of the seat support plate section33is located behind a front end portion of the right frame section94. A concave section33ais provided on a left surface of an intermediate portion of the seat support plate section33in the front-rear direction.

The right side frame30has an arm coupling member34. The arm coupling member34is a member that is fixed to a left surface (a surface positioned on the inner side in the body width direction) of an intermediate portion of the right side frame30in the front-rear direction and to which right end portions of the upper support arm40and the lower support arm50are coupled. An upper protruding plate section34athat extends in the up-down direction is provided to an upper portion of the arm coupling member34in a manner to protrude leftward. The upper protruding plate section34ais formed with an upper through hole34bthat penetrates the upper protruding plate section34ain the front-rear direction. A lower protruding plate section34cthat extends in the up-down direction is provided to a lower portion of the arm coupling member34in a manner to protrude leftward. The lower protruding plate section34cis located behind the upper protruding plate section34a.The lower protruding plate section34cis formed with a lower through hole34dthat penetrates the lower protruding plate section34cin the front-rear direction.

The caster support section32of the right side frame30is formed to extend forward and is lowered toward a front end. A caster attachment section32ais provided to a front end portion of the caster support section32in a manner to protrude downward. To the caster attachment section32a,the right caster13is attached to be turnable about an axis that extends in the up-down direction. Furthermore, a footrest support section32bthat supports the footrest60described below is provided to the front end portion of the caster support section32in a manner to protrude downward. As illustrated inFIG.3, the footrest support section32bis located on the left side (the inner side in the body width direction) of the caster attachment section32a.

Configuration of Footrest

As illustrated inFIG.1, the footrest60for the wheelchair user who is seated on the seat3to place his/her feet is provided to a front portion of the wheelchair body2. The footrest60is configured to couple the footrest support section22b,which is a front end portion of the left side frame20, and the footrest support section32b,which is a front end portion of the right side frame30, and to be foldable in a central portion in the left-right direction.

In other words, the footrest60has a three-part structure having: a left footrest component61that constitutes a left portion of the footrest60; a right footrest component62that constitutes a right portion of the footrest60; and a bracket63that couples a right end portion of the left footrest component61and a left end portion of the right footrest component62in a manner to allow rotation thereof. The bracket63is disposed in the central portion of the footrest60in the left-right direction. Each of the left footrest component61and the right footrest component62is formed of a plate material, and the left footrest component61and the right footrest component62constitute a plate-shaped foot placement section that extends in the left-right direction.

FIG.9is a plan view of the footrest60. A left coupling shaft22cthat extends in the front-rear direction is supported by the left footrest support section22b.A left end portion of the left footrest component61is coupled to the left footrest support section22bvia the left coupling shaft22c.The left footrest component61is rotatable in the up-down direction about an axis of the left coupling shaft22c.The left coupling shaft22cmay rotate with respect to the footrest support section22b,or the left footrest component61may rotate with respect to the left coupling shaft22c.

Similar to the left coupling shaft22cside, a right coupling shaft32cthat extends in the front-rear direction is supported by the right footrest support section32b.A right end portion of the right footrest component62is coupled to the right footrest support section32bvia the right coupling shaft32c.The right footrest component62is rotatable in the up-down direction about an axis of the right coupling shaft32c.

The right end portion of the left footrest component61is formed with a left notch section61ain a central portion in the front-rear direction. The left end portion of the right footrest component62is also formed with a right notch section62ain a central portion in the front-rear direction. The left notch section61aand the right notch section62aare aligned in the front-rear direction. Thus, an opening64is formed between the right end portion of the left footrest component61and the left end portion of the right footrest component62by both of the notch sections61a,62a.

A first coupling shaft63athat extends in the front-rear direction is supported by a left portion of the bracket63. The right end portion of the left footrest component61is rotatably coupled to the bracket63via the first coupling shaft63a.In addition, a second coupling shaft63bthat extends in the front-rear direction is supported by a right portion of the bracket63. The left end portion of the right footrest component62is rotatably coupled to the bracket63via the second coupling shaft63b.

When the footrest60is unfolded, the bracket63is disposed in the opening64that is formed between the right end portion of the left footrest component61and the left end portion of the right footrest component62. Then, when the footrest60is unfolded, the bracket63is held between the left footrest component61and the right footrest component62from both of the left and right sides. More specifically, the bracket63is formed such that a left end portion abuts an edge of the left notch section61aof the left footrest component61when the footrest60is unfolded. In addition, the bracket63is formed such that a right end portion abuts an edge of the right notch section62aof the right footrest component62when the footrest60is unfolded.

Just as described, the footrest60has the three-part structure. The left footrest component61is coupled to the footrest support section22bin the manner to be rotatable in the up-down direction, the right footrest component62is coupled to the footrest support section32bin the manner to be rotatable in the up-down direction, and the bracket63is coupled to the left footrest component61and the right footrest component62in a manner to be rotatable relative to the left footrest component61and the right footrest component62. Thus, the footrest60can be switched from an unfolded state (a usable state) illustrated inFIG.1and the like to a folded state (an unusable state) illustrated inFIG.5and the like, and vice versa. When the footrest60is folded the transition is made from the unfolded state to the folded state, the left footrest component61and the right footrest component62rotate upward such that the footrest60defines a shape forming a convexity in the up direction. When the footrest60is unfolded the transition is made from the folded state to the unfolded state, the left footrest component61and the right footrest component62rotate downward such that the footrest60takes a posture extending in the left-right direction. In other words, a folding direction and an unfolding direction of the footrest60match the up-down direction. Thus, the footrest60does not interfere with folding and unfolding of the wheelchair1.

A rear end portion of the bracket63protrudes higher than upper surfaces of the left footrest component61and the right footrest component62, and this upward protruding portion supports a third coupling shaft63cthat extends in the left-right direction. The third coupling shaft63cis a member for coupling a lower end portion of a rod85, which will be described below, to the bracket63.

Structures of Upper Support Arm and Lower Support Arm

The wheelchair body2is configured that the wheelchair body2can be brought into the folded state illustrated inFIG.5andFIG.6from the unfolded state illustrated inFIG.1toFIG.3and can be brought into the unfolded state from the folded state without using the tool or the like. In the unfolded state, a distance between the left side frame20and the right side frame30is increased, which enables attachment of the seat3. Meanwhile, in the folded state, the distance between the left side frame20and the right side frame30is reduced, which prevents the attachment of the seat3.

In this embodiment, the seat3is configured to be attachable/detachable to/from the wheelchair body2. Accordingly, when the wheelchair1is not in use, the seat3is detached from the wheelchair body2, and the seat3and the wheelchair body2thereby separate from each other. As a result, the seat3and the wheelchair body2can separately be carried due to light weight and can also be made compact. In addition, since the wheelchair body2can be folded, the wheelchair body2becomes compact. Hereinafter, as a structure that makes the wheelchair body2foldable, the upper support arm40and the lower support arm50will be described in detail.

As illustrated inFIG.10toFIG.14, the upper support arm40is formed of plural members, couples the left side frame20and the right side frame30, and is folded in the up-down direction in a central portion thereof in the left-right direction (a longitudinal direction). The lower support arm50couples the left side frame20and the right side frame30, is folded in the up-down direction in a central portion thereof in the left-right direction (a longitudinal direction), and is provided below the upper support arm40. The lower support arm50is also formed of plural members. Here, the number of the support arms is not limited two.

As illustrated inFIG.10, the upper support arm40is configured to extend in the left-right direction when in the unfolded state. The upper support arm40is located right below the seat3. However, since the upper support arm40extends in a substantially horizontal direction, the upper support arm40does not interfere with a cushion portion of the seat3when the wheelchair user is seated. This upper support arm40has: a first upper arm component41that constitutes a left portion of the upper support arm40; a second upper arm component42that constitutes a right portion of the upper support arm40; and an upper coupling member43that couples a right end portion of the first upper arm component41and a left end portion of the second upper arm component42in a manner to allow rotation thereof.

The lower support arm50is configured to be positioned higher toward a left end and toward a right end when in the unfolded state. In other words, the lower support arm50has such a shape that a central portion in the left-right direction protrudes downward when compared to both end portions. However, since there is an empty space between the left and right drive wheels10,11, the lower support arm50in this shape does not cause a problem when in use or the like. This lower support arm50has: a first lower arm component51that constitutes a left portion of the lower support arm50; a second lower arm component52that constitutes a right portion of the lower support arm50; and a lower coupling member53that couples a right end portion of the first lower arm component51and a left end portion of the second lower arm component52in a manner to allow rotation thereof. The first lower arm component51is disposed to be inclined such that the right end portion of the first lower arm component51is positioned lower than a left end portion. The second lower arm component52is disposed to be inclined such that the left end portion of the second lower arm component52is positioned lower than a right end portion.

FIG.15illustrates a positional relationship in the unfolded state between a group including the first upper arm component41and the second upper arm component42and a group including the first lower arm component51and the second lower arm component52. As illustrated inFIG.15, in the back view (same in the front view), a distance between the upper support arm40and the lower support arm50is increased toward the central portion in the left-right direction and is reduced toward a left end and toward a right end.

A left end portion of the first upper arm component41is coupled to the upper protruding plate section24aof the arm coupling member24of the left side frame20via a first upper support shaft41a.The first upper support shaft41aextends in the front-rear direction and is supported in an inserted state in the upper through hole24b.The first upper support shaft41acan rotate about an axis with respect to the left end portion of the first upper arm component41or can rotate about the axis with respect to the upper protruding plate section24a.In other words, the left end portion of the first upper arm component41is coupled to the left side frame20in a manner to be rotatable about the shaft extending in the front-rear direction.

The left end portion and the right end portion of the first upper arm component41are end portions that respectively serve as the left end portion and the right end portion in the unfolded state and respectively serve as a lower end portion and an upper end portion in the folded state. Similarly, the left end portion and a right end portion of the second upper arm component42are end portions that respectively serve as the left end portion and the right end portion in the unfolded state and respectively serve as an upper end portion and a lower end portion in the folded state.

The right end portion of the second upper arm component42is coupled to the upper protruding plate section34aof the arm coupling member34of the right side frame30via a second upper support shaft42a.The second upper support shaft42aextends in the front-rear direction and is supported in an inserted state in the upper through hole34b.The second upper support shaft42acan rotate about an axis with respect to the right end portion of the second upper arm component42or can rotate about an axis with respect to the upper protruding plate section34a.In other words, the right end portion of the second upper arm component42is coupled to the right side frame30in a manner to be rotatable about the shaft extending in the front-rear direction.

The right end portion of the first upper arm component41is coupled to a left portion of the upper coupling member43via a third upper support shaft43a.The third upper support shaft43aextends in the front-rear direction and is supported by the upper coupling member43while penetrating the right end portion of the first upper arm component41in the front-rear direction. The third upper support shaft43acan rotate about an axis with respect to the right end portion of the first upper arm component41or can rotate about the axis with respect to the upper coupling member43. In other words, the right end portion of the first upper arm component41is coupled to the upper coupling member43in a manner to be rotatable about the shaft extending in the front-rear direction.

The left end portion of the second upper arm component42is coupled to a right portion of the upper coupling member43via a fourth upper support shaft43b.The fourth upper support shaft43bextends in the front-rear direction and is supported by the upper coupling member43while penetrating the left end portion of the second upper arm component42in the front-rear direction. The fourth upper support shaft43bcan rotate about an axis with respect to the left end portion of the second upper arm component42or can rotate about the axis with respect to the upper coupling member43. In other words, the left end portion of the second upper arm component42is coupled to the upper coupling member43in a manner to be rotatable about the shaft extending in the front-rear direction.

The left end portion of the first lower arm component51is coupled to the lower protruding plate section24cof the arm coupling member24of the left side frame20via a first lower support shaft51a.The first lower support shaft51aextends in the front-rear direction and is supported in an inserted state in the lower through hole24d.The first lower support shaft51acan rotate about an axis with respect to the left end portion of the first lower arm component51or can rotate about the axis with respect to the lower protruding plate section24c.In other words, the left end portion of the first lower arm component51is coupled to the left side frame20in a manner to be rotatable about the shaft extending in the front-rear direction.

The left end portion and the right end portion of the first lower arm component51are end portions that respectively serve as the left end portion and the right end portion in the unfolded state and respectively serve as an upper end portion and a lower end portion in the folded state. Similarly, the left end portion and the right end portion of the second lower arm component52are end portions that respectively serve as the left end portion and the right end portion in the unfolded state and respectively serve as a lower end portion and an upper end portion in the folded state.

The right end portion of the second lower arm component52is coupled to the lower protruding plate section34cof the arm coupling member34of the right side frame30via a second lower support shaft52a.The second lower support shaft52aextends in the front-rear direction and is supported in an inserted state in the lower through hole34d.The second lower support shaft52acan rotate about an axis with respect to the right end portion of the second lower arm component52or can rotate about the axis with respect to the lower protruding plate section34c.In other words, the right end portion of the second lower arm component52is coupled to the right side frame30in a manner to be rotatable about the shaft extending in the front-rear direction.

The right end portion of the first lower arm component51is coupled to a left portion of the lower coupling member53via a third lower support shaft53a.The third lower support shaft53aextends in the front-rear direction and is supported by the lower coupling member53while penetrating the right end portion of the first lower arm component51in the front-rear direction. The third lower support shaft53acan rotate about an axis with respect to the right end portion of the first lower arm component51or can rotate about the axis with respect to the lower coupling member53. In other words, the right end portion of the first lower arm component51is coupled to the lower coupling member53in a manner to be rotatable about the shaft extending in the front-rear direction.

The left end portion of the second lower arm component52is coupled to a right portion of the lower coupling member53via a fourth lower support shaft53b.The fourth lower support shaft53bextends in the front-rear direction and is supported by the lower coupling member53while penetrating the left end portion of the second lower arm component52in the front-rear direction. The fourth lower support shaft53bcan rotate about an axis with respect to the left end portion of the second lower arm component52or can rotate about the axis with respect to the lower coupling member53. In other words, the left end portion of the second lower arm component52is coupled to the lower coupling member53in a manner to be rotatable about the shaft extending in the front-rear direction.

The upper support arm40is formed as a single arm by coupling the first upper arm component41, the second upper arm component42, and the upper coupling member43. The lower support arm50is formed as a single arm by coupling the first lower arm component51, the second lower arm component52, and the lower coupling member53. In addition, a left end portion of the upper support arm40and a left end portion of the lower support arm50are coupled to the left side frame20. A right end portion of the upper support arm40and a right end portion of the lower support arm50are coupled to the right side frame30. In this way, the left side frame20, the right side frame30, and a pair of the upper support arm40and the lower support arm50in the unfolded state form a truss structure as a structural framework under the seat3. In the truss structure, all joints are hinged joints.

FIG.16illustrates a positional relationship in the folded state between the group including the first upper arm component41and the second upper arm component42and the group including the first lower arm component51and the second lower arm component52. In this embodiment, the upper support arm40is folded when the first upper arm component41and the second upper arm component42rotate upward. Thus, the folding direction of the upper support arm40is the up direction. When being folded, the upper support arm40defines such a shape that forms the convexity in the up direction. Meanwhile, the lower support arm50is folded when the first lower arm component51and the second lower arm component52rotate downward. Thus, a folding direction of the lower support arm50is an opposite direction from the folding direction of the upper support arm40, that is, the down direction. When being folded, the lower support arm50defines such a shape that forms a convexity in the down direction. In addition, as illustrated inFIG.14, the upper support arm40is positioned in front of the lower support arm50.

As illustrated inFIG.15andFIG.16, in the right end portion of the first upper arm component41, plural first upper teeth41bare formed around the axis of the third upper support shaft43a.In the left end portion of the second upper arm component42, plural second upper teeth42bare formed around the axis of the fourth upper support shaft43b.The first upper teeth41band the second upper teeth42bare disposed to mesh with each other. In the right end portion of the first lower arm component51, plural first lower teeth51bare formed around the axis of the third lower support shaft53a.In the left end portion of the second lower arm component52, plural second lower teeth52bare formed around the axis of the fourth lower support shaft53b.The first lower teeth51band the second lower teeth52bare disposed to mesh with each other.

Structure of Retaining Wheelchair Body in Folded State

In this embodiment, a retention mechanism is provided to retain the wheelchair body2in the folded state. By providing the retention mechanism, when being carried, the wheelchair body2in the folded state can easily be carried without being unexpectedly unfolded. The retention mechanism may also include a mechanism that retains the wheelchair body2in the unfolded state. This stabilizes the wheelchair body2in the unfolded state.

Hereinafter, the retention mechanism will be described in detail. For example, as illustrated inFIG.10, the retention mechanism includes: a left pin (a first pin)44aand a right pin (a second pin)44bas a first engaged section provided to the upper support arm40; an engaged plate (a second engaged section)54provided to the lower support arm50; and an engagement section70. The engaged section in this embodiment includes the first engaged section having the left pin44aand the right pin44band the second engaged section having the engaged plate54. However, the engaged section is not limited thereto and may only include one of the first engaged section and the second engaged section. That is, such a structure can be adopted that includes the engaged section provided to at least one of the upper support arm40and the lower support arm50.

As also illustrated inFIG.15andFIG.16, the left pin44aprotrudes rearward from a portion on the right side of a central portion of the first upper arm component41in the longitudinal direction, more specifically, from the left side of the third upper support shaft43a.Meanwhile, the right pin44bprotrudes rearward from a portion on the left side of a central portion of the second upper arm component42in the longitudinal direction, more specifically, from the right side of the fourth upper support shaft43b.The left pin44aand the right pin44bare parallel to each other.

As enlarged inFIG.17, the engaged plate54is disposed in front of the right end portion of the first lower arm component51and the left end portion of the second lower arm component52, and is rotatably attached to the right end portion of the first lower arm component51and the left end portion of the second lower arm component52. More specifically, a front end portion of the third lower support shaft53aand a front end portion of the fourth lower support shaft53bpenetrate the engaged plate54, and each of the third lower support shaft53aand the fourth lower support shaft53bcan rotate about an axis with respect to the engaged plate54. In this way, the first lower arm component51and the second lower arm component52are also coupled by the engaged plate54in a manner to be rotatable relative to each other.

A left protruding section54athat protrudes leftward is formed in an upper left portion of the engaged plate54. A right protruding section54bthat protrudes rightward is formed in an upper right portion of the engaged plate54.

The engagement section70is a portion that engages the left pin44aand the right pin44bduring folding of the upper support arm40and the lower support arm50and thereby prevents relative displacement in the up-down direction of the central portions of the upper support arm40and the lower support arm50in the left-right direction. In addition, the engagement section70engages the engaged plate54during unfolding of the upper support arm40and the lower support arm50and thereby prevents the relative displacement in the up-down direction of the central portions of the upper support arm40and the lower support arm50in the left-right direction.

In this embodiment, the engagement section70is provided to the upper coupling member43, and the engagement section70and the upper coupling member43are integrated. Thus, the engagement section70and the upper coupling member43can constitute a fixed section A (only illustrated inFIG.18). In this case, the engagement section70provided in the fixed section A engages the pins44a,44bor the engaged plate54and thereby prevents the relative displacement in the up-down direction of the central portions of the upper support arm40and the lower support arm50in the left-right direction. However, the engagement section70and the upper coupling member43may not constitute the fixed section A.

As illustrated inFIG.18, the engagement section70includes a left engagement member (a first engagement member)71and a right engagement member (a second engagement member)72. The left engagement member71is supported by a portion on the left side of a central portion of the upper coupling member43in the left-right direction via a left rotary shaft71a.The left rotary shaft71ais disposed below the third upper support shaft43aand near the central portion in the left-right direction, and extends in the front-rear direction. Accordingly, the left engagement member71can rotate about an axis of the left rotary shaft71a.

In a portion above the left rotary shaft71ain the left engagement member71, an upper concave section71bis formed to be opened leftward. In a portion below the left rotary shaft71ain the left engagement member71, a lower concave section71cis formed to be opened rightward.

The right engagement member72is supported by a portion on the right side of the central portion of the upper coupling member43in the left-right direction via a right rotary shaft72a.The right rotary shaft72ais disposed below the fourth upper support shaft43band near the central portion in the left-right direction, and extends in the front-rear direction. Accordingly, the right engagement member72can rotate about an axis of the right rotary shaft72a.

In a portion above the right rotary shaft72ain the right engagement member72, an upper concave section72bis formed to be opened rightward. In a portion below the right rotary shaft72ain the right engagement member72, a lower concave section72cis formed to be opened leftward.

The left pin44a(indicated by an imaginary line inFIG.18) enters the upper concave section71bof the left engagement member71from the left side when the upper support arm40and lower support arm50are folded. Then, the left pin44athat enters the upper concave section71bengages and comes into contact with an inner surface of the upper concave section71b.The right pin44b(indicated by an imaginary line inFIG.18) enters the upper concave section72bof the right engagement member72from the right side when the upper support arm40and lower support arm50are folded. Then, the right pin44bthat enters the upper concave section72bengages and comes into contact with an inner surface of the upper concave section72b.

The left protruding section54aof the engaged plate54enters the lower concave section71cof the left engagement member71from a lower right side when the upper support arm40and lower support arm50are unfolded. Then, the left protruding section54athat enters the lower concave section71cengages and comes into contact with an inner surface of the lower concave section71c.The right protruding section54bof the engaged plate54enters the lower concave section72cof the right engagement member72from a lower left side when the upper support arm40and lower support arm50are unfolded. Then, the right protruding section54bthat enters the lower concave section72cengages and comes into contact with an inner surface of the lower concave section72c.InFIG.18, both of an engagement state during unfolding of the upper support arm40and the lower support arm50and an engagement state during folding thereof are indicated by the imaginary lines. However, in one of the engagement states, the other engagement state cannot be achieved in reality.

FIG.18illustrates a case where the left engagement member71is located at an engagement position at which the left engagement member71engages the left pin44aand the left protruding section54a.When the left engagement member71rotates rightward about the axis of the left rotary shaft71a,the left engagement member71is positioned at a disengagement position at which the left engagement member71does not engage the left pin44aand the left protruding section54a.Similarly,FIG.18illustrates a case where the right engagement member72is located at an engagement position at which the right engagement member72engages the right pin44band the right protruding section54b.When the right engagement member72rotates leftward about the axis of the right rotary shaft72a,the right engagement member72is positioned at a disengagement position at which the right engagement member72does not engage the right pin44band the right protruding section54b.In other words, each of the left engagement member71and the right engagement member72is supported by the upper coupling member43in a manner to be rotatable between the engagement position and the disengagement position.

The engagement section70includes a spring member73that urges each of the left engagement member71and the right engagement member72toward the engagement position. The spring member73is formed of a torsion spring and has an annular section73ain a central portion thereof. A first arm73band a second arm73cextend from the annular section73a.In the central portion of the upper coupling member43in the left-right direction, a pin-shaped spring support section43dis provided above the left rotary shaft71aand the right rotary shaft72aand protrudes rearward. By inserting the spring support section43din the annular section73aof the spring member73, the spring member73is retained in the upper coupling member43.

The first arm73bof the spring member73is locked to a portion above the left rotary shaft71ain the left engagement member71. The second arm73cof the spring member73is locked to a portion above the right rotary shaft72ain the right engagement member72. The spring member73generates an urging force in a direction in which a distance between the first arm73band the second arm73cis increased. As a result, each of the left engagement member71and the right engagement member72is urged toward the engagement position.

When the left pin44aand the right pin44bare engaged with the left engagement member71and the right engagement member72, respectively, the left pin44aand the right pin44bapproach the upper concave sections71b,72bby folding the upper support arm40and lower support arm50in the unfolded state, and enter the upper concave sections71b,72bwhile sliding against circumferential edges of the upper concave sections71b,72b,respectively. Since a folding force is greater than the urging force of the spring member73, the left engagement member71and the right engagement member72rotate against the urging force of the spring member73, and are then brought into the engagement state when the left pin44aand the right pin44bfully enter the upper concave sections71b,72b,respectively.

In addition, when the left protruding section54aand the right protruding section54bare engaged with the left engagement member71and the right engagement member72, respectively, the left protruding section54aand the right protruding section54bapproach the lower concave sections71c,72cby unfolding the upper support arm40and lower support arm50in the folded state, and enter the lower concave sections71c,72cwhile sliding against introduction surfaces71d,72dformed below the lower concave sections71c,72c,respectively. At this time, since an unfolding force is greater than the urging force of the spring member73, the left engagement member71and the right engagement member72rotate against the urging force of the spring member73, and are then brought into the engagement state when the left protruding section54aand the right protruding section54bfully enter the lower concave sections71c,72c,respectively.

As illustrated inFIG.11,FIG.13, and the like, the wheelchair body2includes an operation section80for a switching operation of the engagement section70from the engagement state with the engaged section to the disengagement state. The operation section80is formed of a lever-like member that extends in the front-rear direction, and is provided to penetrate the upper coupling member43in the front-rear direction. An intermediate portion of the operation section80in the front-rear direction is rotatably attached to the upper coupling member43by an attachment shaft80a(illustrated inFIG.11) that extends in the left-right direction. In this way, the operation section80can freely swing about the attachment shaft80a.

A front portion of the operation section80protrudes forward from a front surface of the upper coupling member43. Meanwhile, a rear portion of the operation section80protrudes rearward from a rear surface of the upper coupling member43. As indicated by an imaginary line inFIG.18, the rear portion of the operation section80is disposed above a portion on the right side of the left rotary shaft71ain the left engagement member71and above a portion on the left side of the right rotary shaft72ain the right engagement member72. When the operation section80is operated in a manner to lift the front portion of the operation section80, the rear portion of the operation section80moves downward and presses the left engagement member71and the right engagement member72downward. When the left engagement member71and the right engagement member72are pressed downward by the rear portion of the operation section80, the left engagement member71and the right engagement member72rotate to the disengagement positions against the urging force of the spring member73. In this way, the left pin44aand the right pin44bcan be disengaged from the left engagement member71and the right engagement member72, respectively, and the left protruding section54aand the right protruding section54bcan be disengaged from the left engagement member71and the right engagement member72, respectively.

The upper coupling member43is provided with a handle48. The handle48protrudes forward from the front surface of the upper coupling member43and is positioned above the front portion of the operation section80. The wheelchair body2can be carried by holding the handle48. In addition, a distance in the up-down direction between the handle48and the front portion of the operation section80is set such that the front portion of the operation section80can be lifted by hanging the front portion of the operation section80with fingers in a state of placing a palm of an adult hand on an upper surface of the handle48, for example. In this way, the operation section80can easily be operated by using the handle48. The handle48may protrude rearward.

Coupling Structure of Support Arms and Footrest

In this embodiment, the folding direction and the unfolding direction of the upper support arm40match the folding direction and the unfolding direction of the footrest60, respectively. Thus, a coupling structure is provided to couple the upper support arm40and the footrest60with a highly strong and highly rigid member. More specifically, the wheelchair1includes the rod85that connects the central portion of the upper support arm40in the left-right direction and the central portion of the footrest60in the left-right direction. The rod85is made of a member with high strength and high rigidity such as metal or the CFRP.

As illustrated inFIG.9, a lower end portion (one end portion) of the rod85is coupled to the bracket63of the footrest60via the third coupling shaft63c.Thus, the lower end portion of the rod85is only allowed to rotate about an axis of the third coupling shaft63cwith respect to the bracket63. Meanwhile, an upper end portion (the other end portion) of the rod85is coupled to the front surface of the upper coupling member43, which is located in the central portion of the upper support arm40in the left-right direction, in a manner not to move. As illustrated inFIG.18, in the case where the upper coupling member43constitutes a part of the fixed section A, the rod85can be coupled to the first upper arm component41and the second upper arm component42, which constitute the upper support arm40, via the fixed section A.

When the wheelchair user is seated on the seat3in a state where the wheelchair body2is unfolded and the seat3is attached thereto (a state illustrated inFIG.1), weight of the wheelchair user is applied to the left side frame20and the right side frame30. In this way, a force in the unfolding direction is applied to the upper support arm40and the lower support arm50. The force applied to the upper support arm40is transmitted to the central portion of the footrest60in the left-right direction via the rod85. Since the upper support arm40is also unfolded in the same direction as the unfolding direction of the footrest60, the force in the unfolding direction of the upper support arm40can be applied, as the force in the unfolding direction, to the footrest60. In this way, the footrest60is maintained in the unfolded state. Thus, body rigidity can be improved by using the footrest60.

The force that is applied to the upper support arm40by the seated wheelchair user is transmitted to the bracket63via the rod85. As a result, the bracket63is held between the left footrest component61and the right footrest component62from both of the left and right sides. As a result, rattling of the footrest60is reduced, and thus the body rigidity is further improved.

Unfolding Operation Assistance Mechanism

In this embodiment, an assistance mechanism for an unfolding operation is provided to facilitate the unfolding operation of the wheelchair body2during unfolding of the wheelchair body2. As illustrated inFIG.13andFIG.14, the wheelchair1includes: a wire (a tensioning member)86having a flexibility that is coupled to the upper support arm40and the lower support arm50; a winding device87capable of winding the wire86; and a grip section88. It is configured that a predetermined tensile force input to the wire86can urge the upper support arm40and the lower support arm50, each of which is in the folded state, in the unfolding direction.

The wire86is a member for applying a force in the unfolding direction to the upper support arm40and the lower support arm50in the folded state, and may be made of metal or resin. Instead of the wire86, a member that is long and thin and can be bent or curved, such as a string, a thread, a chain, a rope, or a metal wire, may be used as the tensioning member.

As indicated by an imaginary line inFIG.18, a distal end portion of the wire86is fixed to the rear portion of the operation section80. In other words, since the operation section80is provided to the upper coupling member43, the distal end portion of the wire86is coupled to the upper coupling member43via the rear portion of the operation section80. Thus, the tensile force of the wire86is directly applied to the rear portion of the operation section80.

As illustrated inFIG.14and the like, the wire86that is fixed to the rear portion of the operation section80extends downward, and the lowest end portion of the wire86is coupled to the lower coupling member53of the lower support arm50. More specifically, a rear surface of the lower coupling member53is provided with a pulley53dthat rotates about an axis extending in the left-right direction, and the wire86is coupled to the lower coupling member53in a state where an intermediate portion of the wire86is wound around this pulley53d.Instead of providing the pulley53d,a guide member may be provided to the rear surface of the lower coupling member53. The guide member prevents the intermediate portion of the wire86from being shifted in the left-right direction while allowing the intermediate portion of the wire86to slide against the guide member.

The upper coupling member43is provided with a pedestal section89on which the winding device87can be placed. The pedestal section89is formed to protrude rearward from the rear surface of the upper coupling member43and be lowered to the rear, and a rear portion of the pedestal section89has a shape that is recessed downward. By placing the winding device87in the recessed portion of the pedestal section89, the winding device87is retained in a manner to prevent relative movement to the wheelchair body2in the left-right direction and the front-rear direction. In the folded state, the winding device87that is placed on the pedestal section89is positioned above and away from the pulley53d.

The wire86that is wound around the pulley53dextends upward and is then connected to a winding mechanism (not illustrated) that is provided inside the winding device87. The winding device87is configured to be able to constantly apply a force in a winding direction to the wire86, and any conventionally well-known winding mechanism can be used for the winding device87. A winding force of the wire86by the winding device87(in other words, a force required to eject the wire86) can be set as desired by the winding mechanism. In this embodiment, the winding force is set such that the wire86is ejected when the wire86is pulled downward by a lighter load than weight of the wheelchair body2(weight excluding the winding device87). Although not illustrated, the winding device may be of an electric type. In the case where the winding device is of the electric type, the wire86can be wound by a motor or the like when a switch is operated, for example. Thus, there is no need to lift the winding device.

The grip section88provided on top of the winding device87is a portion that is gripped by the wheelchair user or the like when the wheelchair body2is unfolded. Since the grip section88is provided on top of the winding device87, the grip section88can easily be gripped from above. Thus, the grip section88is attached, via the winding device87, to an opposite side of the wire86from a side thereof that is coupled to the upper support arm40and the lower support arm50.

When the folded wheelchair body2is unfolded, for example, the wheelchair user grips the grip section88to lift the winding device87, and the wire86is then pulled upward. At this time, the wire86pulls the rear portion of the operation section80downward. Consequently, the operation section80is operated by the wire86, and the left engagement member71and the right engagement member72each rotate to the disengagement position. In addition, the wire86is coupled to the central portions of the upper support arm40and the lower support arm50in the left-right direction. Accordingly, when the tensile force of the wire86becomes the predetermined tensile force, the upper support arm40is urged in the unfolding direction, and the lower support arm50is also urged in the unfolding direction. As a result, the upper support arm40and the lower support arm50are unfolded.

The winding device87is configured to be able to eject the wire86until the winding device87moves upward from the placement position (indicated by a solid line inFIG.14), at which the winding device87is placed on the pedestal section89, by a predetermined distance and is disposed at a departure position (indicated by an imaginary line inFIG.14) away from the pedestal section89. Since the wire86is flexible, a movement direction of the grip section88gripped by the wheelchair user is unlikely to be regulated by the upper support arm40and the lower support arm50. Thus, the grip section88can move relatively freely. This allows the wheelchair user to input the predetermined tensile force while pulling the grip section88toward himself/herself and to move the grip section88to a position at which the wheelchair user can easily input the tensile force. As a result, the unfolding operation of the wheelchair body2is facilitated.

An ejection amount of the wire86by the winding device87is regulated such that the winding device87does not move upward from the placement position, at which the winding device87is placed on the pedestal section89, by a longer distance than the predetermined distance. In other words, when a distance in the up-down direction between the placement position and the departure position is long, the winding device87has to be lifted to a higher position during the unfolding operation, which possibly makes the unfolding operation difficult, especially in the seated state. In order to handle such a problem, the ejection amount of the wire86is determined in advance to prevent the need for lifting the winding device87to the higher position during the unfolding operation. This further facilitates the unfolding operation.

When the lower support arm50is unfolded, the central portion of the lower support arm50in the left-right direction moves upward, and thus a distance between the pulley53dand the winding device87, which is placed on the pedestal section89, is reduced. This results in the excess wire86. However, since an excess portion of the wire86is wound by the winding device87, the wire86is unlikely to become slack and tangled with another member or the like.

Seat Attachment/Detachment Structure

As illustrated inFIG.4, the seat3includes a seat cushion section91, on which the wheelchair user is seated, a back cushion section92, and a seat frame90. The seat frame90is provided to a lower portion of the seat3and is configured to be attachable to the left side frame20and the right side frame30from above.

As illustrated inFIG.19andFIG.20, the seat frame90includes: the left frame section93that is provided to the lower portion of the seat3and extends in the front-rear direction in a left portion of the seat3; the right frame section94that is provided to the lower portion of the seat3and extends in the front-rear direction in a right portion of the seat3; and a coupling frame section95(illustrated inFIG.20) that extends between the left frame section93and the right frame section94and couples the left frame section93and the right frame section94. The left frame section93is a portion that is accommodated in the left seat frame accommodation section21band supported by the seat support plate section23, and can be attached/detached to/from the upper frame section21of the left side frame20. The right frame section94is a portion that is accommodated in the right seat frame accommodation section31band supported by the seat support plate section33, and can be attached/detached to/from the upper frame section31of the right side frame30.

Since the left frame section93and the right frame section94have a bilaterally-symmetrical structure, the right frame section94will be described in detail below. As illustrated inFIG.22andFIG.25, the right frame section94is configured to hold the seat support plate section33from the left and right sides while being supported by the seat support plate section33. The left surface and a right surface of this seat support plate section33are parallel to each other and extend in the up-down direction. A lower surface of the seat support plate section33extends in the left-right direction and the front-rear direction.

The right frame section94includes a frame abutment section101, an abutment member102, and a shaft member103. The frame abutment section101is integrally molded into a body portion of the right frame section94. Although the frame abutment section101and the abutment member102are illustrated to be solid inFIG.22, the frame abutment section101and the abutment member102may be hollow. The frame abutment section101is formed by a portion of the right frame section94in the front-rear direction and is disposed to abut the right surface of the seat support plate section33from the right side. The abutment member102is a member that abuts the left surface of the seat support plate section33from the left side and is disposed on the inner side of the seat frame90in the body width direction. A lower portion of the abutment member102is disposed in the concave section33a(illustrated inFIG.8) of the seat support plate section33.

As illustrated inFIG.23, the abutment member102has a block shape and is supported by the shaft member103to be rotatable about an axis X extending in the front-rear direction with respect to an upper portion of the frame abutment section101.FIG.24illustrates a state where the abutment member102rotates in a direction away from the frame abutment section101(the left direction). As illustrated inFIG.22, an upper left portion (a portion on the inner side in the vehicle width direction) of the abutment member102is formed with a shaft through hole102athat penetrates the shaft member103. As indicated by broken lines inFIG.23, the shaft member103is set to be longer than a dimension in the front-rear direction of the abutment member102, a front end portion of the shaft member103protrudes forward from a front surface of the abutment member102, and a rear end portion of the shaft member103protrudes rearward from a rear surface of the abutment member102.

The front end portion and the rear end portion of the shaft member103are each supported by the body portion of the right frame section94. The front end portion of the shaft member103is supported by a portion of the right frame section94that is located in front of the abutment member102, and the rear end portion of the shaft member103is supported by a portion of the right frame section94that is located behind the abutment member102. The front end portion and the rear end portion of the shaft member103may be supported by the body portion of the right frame section94in the manner to be rotatable about the axis X, or the abutment member102may be supported by the shaft member103in a manner to be rotatable about the axis X.

As illustrated inFIG.25, the right frame section94is provided with an urging member105that constantly urges the abutment member102in a direction away from the frame abutment section101. The urging member105is formed of a coil spring that is disposed between the frame abutment section101and the abutment member102in a manner that a compression direction of the coil spring is oriented in the left-right direction. The urging member105separates downward from the shaft member103. A left portion of the urging member105is accommodated in a spring accommodation section102fthat is formed in the abutment member102. The spring accommodation section102fis configured as a concave portion that is opened to a right surface of the abutment member102. The left end portion of the urging member105abuts a bottom surface of the spring accommodation section102f.In a state where a left portion of the urging member105is accommodated in the spring accommodation section102f,the urging member105is held by an inner surface of the spring accommodation section102f.This suppresses falling of the urging member105.

A right end portion of the urging member105abuts an intermediate portion of the frame abutment section101in the up-down direction. Accordingly, an urging force of the urging member105is applied in the left-right direction in the portion that separates downward from the shaft member103. Thus, the urging force is a force that causes rotation of the abutment member102about the axis X in the left direction. Here, the urging member105is not limited to the coil spring, and may be formed of an elastic member such as a string spring, an elastomer, or rubber.

As illustrated inFIG.26, the right frame section94has a locking section110that locks the abutment member102in an abutment state with the seat support plate section33. The locking section110has a lock pin111and a coil spring112. The lock pin111and the coil spring112are disposed on the rear side of the abutment member102.

The right frame section94is provided with a lock pin accommodation box113that is adjacent to the rear side of the abutment member102. Inside the lock pin accommodation box113, the lock pin111is disposed in a posture extending in the front-rear direction. The lock pin111is supported by the lock pin accommodation box113in a manner to be movable in the front-rear direction, and can be switched between an advanced state where a front end portion (a distal end portion) of the lock pin111protrudes from a front surface of the lock pin accommodation box113and a retracted state where the front end portion of the lock pin111does not protrude from the front surface of the lock pin accommodation box113.

The coil spring112is also accommodated in the lock pin accommodation box113. One end portion of the coil spring112is retained inside the lock pin accommodation box113, and the other end portion of the coil spring112engages the lock pin111. In this state, the coil spring112urges the lock pin111in an advancing direction.

A rear wall portion of the abutment member102is formed with a hole102bin which the distal end portion of the lock pin111is inserted. A radial center of the hole102bis positioned to coincide with an axis of the lock pin111in a state where the abutment member102abuts the seat support plate section33. Since an urged direction of the lock pin111by the coil spring112is the front direction, the urged direction coincides with a direction in which the distal end portion of the lock pin111is inserted in the hole102b.By inserting the distal end portion of the lock pin111in the hole102b,the abutment member102does not rotate in the left-right direction and is locked in an abutment state with the seat support plate section33.

An inner surface of the hole102bis provided with a guide surface102cthat guides the lock pin111into the hole102b.The guide surface102cis provided in a rear portion of the inner surface of the hole102b,that is, a portion on the front side in the insertion direction of the lock pin111with the insertion direction being a reference. The guide surface102cis formed as a tapered surface, an inner diameter of which is increased toward the front side in the insertion direction. The guide surface102cmay be provided as needed. For example, although not illustrated, a diameter of the lock pin111may be reduced toward the distal end. This can exert the same effect as that in the case of providing the guide surface102c,that is, such an effect that the lock pin111is reliably inserted in the hole102band thus can lock the abutment member102.

As illustrated inFIG.22andFIG.24, a convex section39is provided to an upper surface of the seat support plate section33of the right side frame30in a manner to protrude upward. The convex section39is formed of a different member from the seat support plate section33and is fixed to the seat support plate section33by using a fastening member (not illustrated) or the like. However, the convex section39may be integrally molded into the seat support plate section33.

The convex section39is a portion that presses the abutment member102from below and thereby causes the abutment member102to rotate in the direction, in which the portion of the abutment member102below the axis X abuts the seat support plate section33of the right side frame30, when the seat frame90is attached to the side frames20,30. More specifically, while a left surface39aof the convex section39extends in the up-down direction from an upper portion to a lower portion of the convex section39, an upper portion of a right surface39bof the convex section39is configured as an inclined surface39cinclined to a vertical plane such that the inclined surface39cis located leftward to an upper end.

The upper portion of the abutment member102is provided with a protruding section104that protrudes in a direction away from the axis X, that is, rightward and downward. A convex surface104athat protrudes downward and leftward is formed on a left surface of the protruding section104. The convex surface104ais located above a lower end portion of the protruding section104. A distance in the left-right direction between the convex surface104aand an inner surface102hof the abutment member102is set such that the convex section39of the right side frame30can be disposed therebetween.

An upper end portion102don the right side of the abutment member102is formed to separate leftward from an upper end portion101don the left side of the frame abutment section101. In this way, a clearance for allowing the rotation of the abutment member102is provided between the upper end portion102don the right side of the abutment member102and the upper end portion101don the left side of the frame abutment section101.

A rib-shaped section101ethat extends in the front-rear direction is provided on a left surface of the frame abutment section101. As illustrated inFIG.25, the right end portion of the urging member105abuts the rib-shaped section101e.This rib-shaped section101emay be provided as needed, and may not be provided.

As illustrated inFIG.24, when the seat frame90is attached to the right side frame30, the seat frame90is disposed above the right side frame30and thereafter moves downward. The convex section39is disposed to press a portion of the abutment member102on the right side (one side in the left-right direction) of the axis X. More specifically, a position of the convex section39is set such that the inclined surface39cof the convex section39abuts the convex surface104aof the abutment member102and presses the convex surface104aupward.

As illustrated inFIG.22, the abutment member102extends to a position below the seat support plate section33along the left surface of the seat support plate section33of the right side frame30. A lower end portion of the abutment member102is formed with a protruding section102ethat is disposed to protrude rightward (one side in the left-right direction) and oppose the lower surface of the seat support plate section33. A predetermined space S (illustrated inFIG.22) is provided between the protruding section102eof the abutment member102and the lower surface of the seat support plate section33.

In addition, as illustrated inFIG.23andFIG.27, an intermediate portion of the convex section39in the front-rear direction is formed with a notched section39din which an intermediate portion of the urging member105in the left-right direction can be accommodated. The notched section39dis opened upward. When the convex section39is inserted between the convex surface104aand the inner surface102hof the abutment member102, the urging member105is accommodated in the notched section39dfrom an open portion of the notched section39d.

Thus, in a state before the seat frame90is attached to the right side frame30, as illustrated inFIG.24, the abutment member102rotates about the axis X in the left direction and is stopped. This stop position is set appropriately and can be set by providing a member such as a stopper. In the state where the abutment member102has rotated leftward, a distance between the abutment member102and the frame abutment section101is increased. Thus, the convex section39can easily be inserted between the abutment member102and the frame abutment section101.

Then, when the right frame section94of the seat frame90is disposed above the right side frame30and then moves downward during the attachment of the seat frame90to the right side frame30, the convex section39presses the portion of the abutment member102on the right side of the axis X upward from below. Consequently, the abutment member102rotates about the axis X in the right direction. A rotation amount of the abutment member102in the right direction corresponds to an insertion amount of the convex section39between the convex surface104aand the inner surface102h.Thus, as the convex section39is deeply inserted between the convex surface104aand the inner surface102h,the rotation amount of the abutment member102in the right direction is increased.

A shape and a size of the convex section39, the space S between the protruding section102eand the lower surface of the seat support plate section33, and the like are set such that the lower surface of the seat support plate section33is located above the protruding section102eof the abutment member102at a stage immediately before the right frame section94is placed on the seat support plate section33. Thus, even in the case where the protruding section102ehas the shape that protrudes rightward, the protruding section102edoes not interfere with the left surface of the seat support plate section33until the right frame section94is completely placed on the seat support plate section33.

Thereafter, until the right frame section94is completely placed on the seat support plate section33, the protruding section102erotates to the position at which the protruding section102eopposes the lower surface of the seat support plate section33. Then, at the stage where the right frame section94is completely placed on the seat support plate section33, the protruding section102eis disposed right below the seat support plate section33as illustrated inFIG.22, the lock pin111, which is urged by the coil spring112, is inserted in the hole102bof the abutment member102as illustrated inFIG.26, and the abutment member102is thereby locked.

As illustrated inFIG.22, the protruding section102eis disposed right below the seat support plate section33. Thus, when the seat support plate section33, which is held by the frame abutment section101and the abutment member102, moves downward to be removed from the position between the frame abutment section101and the abutment member102in the attachment state of the seat3, the protruding section102eof the abutment member102contacts the lower surface of the seat support plate section33. This ensures that the seat support plate section33is not unexpectedly removed from the position between the frame abutment section101and the abutment member102.

As it has been described so far, the right frame section94can move downward until the right frame section94is completely placed on the seat support plate section33. In other words, the right frame section94moves downward until being placed on the seat support plate section33. Thereafter, a downward load that is applied to the right frame section94when the wheelchair user is seated on the seat3is almost entirely received by the upper surface of the seat support plate section33and is hardly applied to the abutment member102and the shaft member103.

Meanwhile, when the abutment member102rotates rightward until the right frame section94is completely placed on the seat support plate section33, the lower portion of the right surface of the abutment member102abuts the right surface of the seat support plate section33, and the seat support plate section33is held in the left-right direction by the frame abutment section101and the abutment member102. This can facilitate the attachment of the seat3and suppress rattling of the attached seat3.

As illustrated inFIG.4,FIG.19,FIG.20, and the like, the seat3has a seat back frame96that supports the back cushion section92. The back cushion section92and the seat back frame96constitute a seat back section B.

A cross member97that extends in the left-right direction is provided in an intermediate portion of the seat back frame96in the up-down direction. A lower end portion of the seat back frame96is supported by a rear end portion of the seat frame90via a tilting section98. The tilting section98is a portion that can tilt the seat back frame96forward. A pressing section99is provided on each of the left and right sides of lower portions of the tilting sections98. The pressing section99presses respective one of the rear end portion of the upper frame section21of the left side frame20and the rear end portion of the upper frame section31of the right side frame30from behind.

When the seat3is detached from the left side frame20and the right side frame30, the pressing sections99are released from the rear end portions of the upper frame sections21,31by tilting the seat back frame96forward. When the seat3is attached, an operation is performed to set the seat back frame96, which is tilted forward, rearward. In this way, the pressing sections99press the rear end portions of the upper frame sections21,31, thereby preventing rattling of the seat3.

As illustrated inFIG.28, the cross member97in the seat back section B is provided with an unlocking operation section120. The unlocking operation section120includes: an unlocking mechanism121that is provided in a central portion of the cross member97in the left-right direction; and an unlocking lever122that is provided to protrude downward from the cross member97. The unlocking mechanism121includes a left swing member123and a right swing member124that are respectively supported by support shafts123a,124ain a manner to be freely swingable in the up-down direction with respect to the cross member97. The unlocking lever122is disposed in a posture extending in the up-down direction, and an upper end portion of the unlocking lever122is rotatably coupled to the left swing member123and the right swing member124via rotary shafts122a.Accordingly, when the unlocking lever122moves upward, the left swing member123and the right swing member124swing upward about the support shafts123a,124a, respectively.

A base end portion of a right operation wire131for operating the lock pin111is connected to a portion below the support shaft124ain the right swing member124. The right operation wire131runs through the cross member97and the seat back frame96, and reaches the inside of the right frame section94as illustrated inFIG.26. A distal end portion of the right operation wire131is connected to a base end portion of the lock pin111via a connection member131a.In other words, since the locking section110is coupled to the unlocking operation section120via the right operation wire131, an urging force of the coil spring112is applied to the right operation wire131.

In addition, since the lock pin111is disposed on the rear side of the abutment member102, the lock pin111and the unlocking operation section120can be brought close to each other. As a result, a length of the right operation wire131can be reduced, which facilitates handling of the right operation wire131and thus ensures favorable operability during unlocking.

When the right swing member124swings upward by the unlocking lever122, the right operation wire131is pulled, and a pulling force of this right operation wire131is applied to the lock pin111in a removal direction (an unlocking direction) from the hole102b.

As illustrated inFIG.28, similar to the right side, a left operation wire130is connected to the left swing member123. This left operation wire130is a member for unlocking a left lock pin (not illustrated). In this embodiment, the left frame section93and the right frame section94have a bilaterally-symmetrical structure. However, the abutment member102may not be provided to one thereof.

Meanwhile, when the seat3is detached, the unlocking operation section120is operated, and an operating force thereof is transmitted to the lock pin111via the right operation wire131for unlocking. At this time, since the unlocking operation section120is provided to the seat back section B, which is positioned higher than the seat cushion section91, the favorable operability of the unlocking operation section120is ensured.

When the seat3is pulled upward and lifted in an unlocked state of the abutment member102, the convex section39moves downward relative to the abutment member102due to the provision of the space S (illustrated inFIG.22) between the protruding section102eand the lower surface of the seat support plate section33. Then, the abutment member102rotates about the axis X in the left direction by the urging force of the urging member105, and the protruding section102emoves to the left side of the seat support plate section33. Thus, the convex section39can completely be removed. Even when the protruding section102eis provided, just as described, the seat3does not interfere with the protruding section102eduring the attachment and the detachment of the seat3due to the provision of the space S.

The above-described embodiment is merely illustrative in all respect and thus should not be construed in a restrictive manner. Furthermore, modifications and changes that fall within the claims and equivalents thereof fall within the scope of the present disclosure.

As it has been described herein, the wheelchair according to the present disclosure can be used, for example, when being carried in an automobile or the like.