wheelchair

Abstract

The seat cushion can be securely locked to the chassis to prevent it from coming loose, while the locking and unlocking operations are simplified for improved usability. [Solution] The upper portion 31 has a front end with a chassis-side inclined surface 31b that protrudes forward as it goes upward, and a rear end with an engaging recess 31c. The seat cushion includes a claw portion 75 that rotates in a direction toward and toward the rear end of the upper portion 31 in accordance with the rotation of the seat back member 73. The front lower part of the vertical member 81 has a cushion-side inclined surface 81h that matches the chassis-side inclined surface 31b and protrudes rearward as it goes downward. The chassis-side inclined surface 31b and the cushion-side inclined surface 81h interlock, and when the seat back member 73 is in the upright position, the claw portion 75 enters the engaging recess 31c and engages.

Description

Technical Field

[0001] The present disclosure relates to a wheelchair in which a seat cushion is configured to be detachable from a chassis frame.

Background Art

[0002] For example, Patent Document 1 discloses a folding wheelchair in which a seat cushion on which a wheelchair user sits is detachable from a chassis. The chassis of this type of foldable wheelchair has a pair of left and right chassis frames and a link mechanism that connects the left and right chassis frames to transition between a folded state and a deployed state. When not in use, after removing the seat cushion from the chassis, the left and right chassis frames can be brought close to each other in the vehicle width direction by the operation of the link mechanism, making it compact and enhancing portability.

[0003] Further, in Patent Document 1, in a state where the seat cushion is attached to the chassis, the seat cushion is fixed to the left and right chassis frames by pins protruding in the front-rear direction from the seat cushion.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, when a wheelchair user uses a wheelchair in a folded state, first, the chassis in the folded state is placed on the ground and deployed. Then, the seat cushion is attached to the chassis. In order to prevent the seat cushion from accidentally coming off when attached to the chassis, it needs to be locked, but the locking operation and unlocking operation should be made as simple as possible.

[0006] On the other hand, when the seat cushion is locked to the chassis, there is a need to securely fasten it so that it does not easily come off the chassis, which is contrary to the desire to simplify the locking and unlocking operations.

[0007] The problems described above are not limited to folding wheelchairs; they can also occur when attaching a removable seat cushion to a non-folding chassis.

[0008] This disclosure is made in view of the above points, and its purpose is to enable the seat cushion to be securely locked in place so that it does not come off when attached to the chassis, while simplifying the locking and unlocking operations to improve operability. [Means for solving the problem]

[0009] To achieve the above objective, one aspect of this disclosure may provide a wheelchair comprising a pair of left and right chassis frames that pivotally support wheels outward in the width direction of the vehicle, and a separate seat cushion that is mounted on the left and right chassis frames at specific front-rear positions.

[0010] The chassis frame has a pair of left and right cushion mounting members that extend in the front-rear direction at positions close to the inside of the left and right wheels. The cushion mounting members have a front end with a chassis-side inclined surface that protrudes forward as it goes upward, and a rear end with an engaging recess that is recessed toward the front.

[0011] The seat cushion includes a pair of left and right vertical members that extend in the front-rear direction at a position overlapping the cushion mounting member in a plan view, a seat back member that is rotatably supported in the front-rear direction by hinge portions provided at the rear of the left and right vertical members and displaces between an upright position and a forward-tilted position, and a claw portion that is connected to the pivot point side of the hinge portion on the seat back member and rotates in a direction toward and toward the rear end of the cushion mounting member in accordance with the rotation of the seat back member.

[0012] A cushion-side inclined surface is formed on the lower front side of the vertical member, which matches the chassis-side inclined surface and protrudes further rearward as it goes down. When the seat cushion is placed on the chassis frame, the chassis-side inclined surface and the cushion-side inclined surface interlock, and in the upright position of the seat back member, the claw portion enters and engages with the engagement recess of the cushion mounting member, thereby fixing the vertical member to the cushion mounting member.

[0013] With this configuration, by removing the seat cushion from the chassis frame and folding the seat back member forward, the seat back member is stored, making it easy to carry and store the seat cushion.

[0014] When attaching the seat cushion to the chassis frame, the seat cushion is placed on the chassis frame, and the inclined surface on the chassis side and the inclined surface on the cushion side are interlocked. Furthermore, the seat back member, which is in the forward-folding position, is rotated around the pivot point of the hinge to the upright position. When the seat back member is rotated to the upright position, the claw portion approaches the rear end of the cushion mounting member, enters the engaging recess, and engages. This locks the seat cushion in place, fixing it to the chassis frame.

[0015] On the other hand, when removing the seat cushion fixed to the chassis frame, the seat back member, which is in the upright position, is rotated around the pivot point of the hinge to the forward-folding position. When the seat back member is rotated to the forward-folding position, the claw portion separates from the rear end of the cushion mounting member, and thus disengages from the engagement recess. This releases the lock of the seat cushion from the chassis frame.

[0016] In other words, locking and unlocking can be performed by switching the seatback member from the upright position to the folded-forward position, and vice versa. This simplifies the locking and unlocking operations, resulting in improved operability.

[0017] The outer portion of the cushion mounting member in the vehicle width direction may be provided with an outer embankment that protrudes upward and extends in the front-rear direction. In this case, the vertical member can be firmly integrated with the cushion mounting member by fitting it into the inner side of the outer embankment in the vehicle width direction.

[0018] The hinge portion may be attached to the pivot point side of the seat back member, as well as to the base end of the claw portion. In this case, when the seat back member is in the upright position, the pivot point can be positioned forward of the pivot point side of the seat back member and the base end of the claw portion. Furthermore, when the seat back member is in the upright position, the claw portion can be positioned rearward and downward of the pivot point.

[0019] Furthermore, when the seat back member is in the forward-folded position, the claw portion may be positioned above and behind the rear end of the cushion mounting member. In this case, the rotational trajectory of the claw portion may be set such that, as the seat back member rotates from the forward-folded position to the upright position, the claw portion moves downward while simultaneously moving forward to enter the engagement recess. This ensures that when the seat back member is in the forward-folded position, the claw portion is reliably disengaged from the engagement recess, making it easy to remove the seat cushion, while when the seat back member is in the upright position, the claw portion is reliably engaged with the engagement recess. [Effects of the Invention]

[0020] As explained above, the seat cushion can be securely locked to the chassis to prevent it from coming off, while the locking and unlocking operations can be simplified to improve usability. [Brief explanation of the drawing]

[0021] [Figure 1]FIG. 1 is a perspective view of a wheelchair according to an embodiment of the present invention as seen from the front. [Figure 2] FIG. 2 is a perspective view of the wheelchair as seen from the left side. [Figure 3] FIG. 3 is a left side view of the wheelchair. [Figure 4] FIG. 4 is a perspective view of the seat cushion as seen from the left side. [Figure 5] FIG. 5 is a view corresponding to FIG. 2 showing the state where the seat cushion is removed. [Figure 6] FIG. 6 is a perspective view of the wheelchair body with the left and right wheels omitted as seen from the front. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. 6. [Figure 8] FIG. 8 is a cross-sectional view taken by cutting along a vertical plane passing through the center in the left-right direction of the wheelchair and extending in the front-rear direction. [Figure 9] FIG. 9 is a cross-sectional view taken along line IX-IX in FIG. 6. [Figure 10] FIG. 10 is a perspective view of the seat cushion with the seat surface portion and the seat back omitted as seen from the lower front side. [Figure 11] FIG. 11 is a perspective view of the seat cushion with the seat surface portion and the seat back omitted as seen from the lower rear side. [Figure 12] FIG. 12 is a view corresponding to FIG. 7 showing the state before the seat cushion is placed. [Figure 13] FIG. 13 is a view corresponding to FIG. 7 showing the state after the seat cushion is placed. [Figure 14] FIG. 14 is a perspective view of the vicinity of the right hinge portion of the seat cushion with the seat back member in the upright position as seen from below. [Figure 15] FIG. 15 is a perspective view of the seat cushion with the seat back member in the forward-tilted position as seen from the left side. [Figure 16] FIG. 16 is a view corresponding to FIG. 9 showing the state where the claw portion is engaged with the chassis frame.

MODE FOR CARRYING OUT THE INVENTION

[0022] Embodiments of the present invention will be described in detail below with reference to the drawings. The following description of preferred embodiments is essentially illustrative and is not intended to limit the present invention, its applications, or its uses.

[0023] Figure 1 is a perspective view of the wheelchair 1 according to an embodiment of the present invention, viewed from the front and diagonally above. Figure 2 is a perspective view of the wheelchair 1 according to an embodiment of the present invention, viewed from the left side. Figure 3 is a left side view of the wheelchair 1. Figure 4 shows the removed seat cushion 3, and Figure 5 shows the wheelchair body 2 with the seat cushion 3 removed.

[0024] This wheelchair 1 is configured so that the seat cushion 3 can be removed from the wheelchair body 2 without the need for tools, and comprises a wheelchair body 2 and a separate seat cushion 3 that can be attached to and removed from the wheelchair body 2. The wheelchair body 2 with the seat cushion 3 removed is configured to be foldable, and therefore the wheelchair 1 according to this embodiment is a foldable wheelchair in which a wheelchair user can sit, i.e., a folding wheelchair.

[0025] In this description of the embodiment, the direction of travel of the wheelchair 1 when moving forward is simply referred to as "forward," and the front of the wheelchair 1 corresponds to the front of the wheelchair user (not shown) seated in the wheelchair 1. Similarly, the direction of travel of the wheelchair 1 when moving backward is simply referred to as "rear," and the rear of the wheelchair 1 corresponds to the rear of the wheelchair user seated in the wheelchair 1. The front-rear direction of the wheelchair 1 is also the longitudinal direction of the vehicle body. Furthermore, the left side of the wheelchair user seated in the wheelchair 1 is the left side of the vehicle body of the wheelchair 1, and is simply referred to as "left." In addition, the right side of the wheelchair user seated in the wheelchair 1 is the right side of the vehicle body of the wheelchair 1, and is simply referred to as "right." The left-right direction of the wheelchair 1 is the width direction of the vehicle body, and is also referred to as the vehicle width direction. Furthermore, the "upper side" of the wheelchair 1 is the side that is at the top when placed on a horizontal surface in a seated state, and the "lower side" of the wheelchair 1 is the side that is at the bottom when placed on a horizontal surface in a seated state.

[0026] The wheelchair body 2 is the part that makes up the chassis of the wheelchair 1. The wheelchair body 2 includes a pair of left and right drive wheels 10 and 11, a pair of left and right casters 12 and 13, a pair of left and right chassis frames 20 and 30, a linkage mechanism 40 (shown in Figures 5 and 6), and a foldable footrest 60. The seat cushion 3 is placed on the pair of left and right chassis frames 20 and 30 at a specific front-to-back position.

[0027] The left drive wheel 10 is pivotally supported on the left side of the left chassis frame 20 in the vehicle width direction (left side). The right drive wheel 11 is pivotally supported on the right side of the right chassis frame 30 in the vehicle width direction (right side). The left drive wheel 10 and the right drive wheel 11 are large-diameter wheels that a wheelchair user seated on the seat cushion 3 can hold by hand and rotate forward or backward, and can also be called drive rear wheels as they are located at the rear of the wheelchair body 2. The left drive wheel 10 and the right drive wheel 11 have a structure in which rubber tires 10b and 11b are attached to the outer circumference of the wheels 10a and 11a, respectively. Handrims 10c and 11c are provided on the outer side of the wheels 10a and 11a in the vehicle width direction, respectively, for the wheelchair user to hold by hand when driving.

[0028] On the other hand, the left caster 12 and the right caster 13 are wheels used to change the direction of travel of the wheelchair 1, and are smaller in diameter than the left drive wheel 10 and the right drive wheel 11. Since the left caster 12 and the right caster 13 are located on the front side of the wheelchair body 2, they can also be called front wheels for changing the direction of travel.

[0029] As shown in Figures 5 and 6, the left chassis frame 20 comprises a left upper edge portion 21 and a left caster support portion 22. The left upper edge portion 21 extends in the longitudinal direction at a height between the central axis (wheel axis) 10d of the left drive wheel 10 and the upper outer edge of the left drive wheel 10, and is located close to the inner side (right side) in the vehicle width direction of the left drive wheel 10. Since this is the part on which the left side of the seat cushion 3 is placed, it can also be called the left cushion mounting member. The central axis 10d of the left drive wheel 10 is the rotational axis of the wheel 10a and is pivotally supported below the left upper edge portion 21 on the left chassis frame 20. The outer edge of the left drive wheel 10 is composed of the outer edge of the tire 10b. The upper outer edge of the left drive wheel 10 is composed of the outer edge of the tire 10b that is located above the central axis 10d of the left drive wheel 10. The height between the central axis 10d of the left drive wheel 10 and the upper outer edge of the left drive wheel 10 is above the central axis 10d of the left drive wheel 10 and below the upper outer edge of the left drive wheel 10.

[0030] The left caster support portion 22 is formed to extend forward from the middle of the left upper edge portion 21 in the front-rear direction, and to be positioned lower as it approaches the front end. The left caster 12 is attached to the front end of the left caster support portion 22 so as to be able to pivot around an axis that extends in the vertical direction.

[0031] The right chassis frame 30 has a symmetrical structure with the left chassis frame 20 and includes a right upper edge portion 31 and a right caster support portion 32. The right upper edge portion 31 extends in the longitudinal direction at a height between the central axis (wheel axis) 11d (shown in Figure 8) of the right drive wheel 11 and the upper outer edge of the right drive wheel 11, at a position close to the inner side (left side) in the vehicle width direction of the right drive wheel 11, and since it is the part on which the right side of the seat cushion 3 is placed, it can also be called the right cushion placement member. The central axis 11d of the right drive wheel 11 is the rotational axis of the wheel 11a and is pivotally supported below the right upper edge portion 31 on the right chassis frame 30. The outer edge of the right drive wheel 11 is composed of the outer edge of the tire 11b. The upper outer edge of the right drive wheel 11 is composed of the outer edge of the tire 11b that is located above the central axis 11d of the right drive wheel 11. The height between the central axis 11d of the right drive wheel 11 and the upper outer edge of the right drive wheel 11 is above the central axis 11d of the right drive wheel 11 and below the upper outer edge of the right drive wheel 11. The central axis 11d of the right drive wheel 11 and the central axis 10d of the left drive wheel 10 are located on the same straight line extending in the vehicle width direction.

[0032] The right caster support portion 32 is formed to extend forward from the middle of the right upper edge portion 31 in the front-rear direction, and to be positioned lower as it approaches the front end. The right caster 13 is mounted to the front end of the right caster support portion 32 so as to be able to pivot around an axis that extends in the vertical direction.

[0033] The link mechanism 40 shown in Figure 6 connects the inner side of the left chassis frame 20 in the vehicle width direction to the inner side of the right chassis frame 30 in the vehicle width direction, and is a folding mechanism that transitions between a folded state in which the left chassis frame 20 and the right chassis frame 30 are close to each other in the vehicle width direction and an unfolded state in which the left chassis frame 20 and the right chassis frame 30 are farthest apart in the vehicle width direction. Because the wheelchair 1 includes the link mechanism 40, the wheelchair body 2 can be transitioned from the unfolded state to the folded state and from the folded state to the unfolded state without the use of tools or the like. When the wheelchair body 2 is in the unfolded state, the seat cushion 3 can be attached to the wheelchair body 2 by placing it from above on the upper part of the left chassis frame 20 and the upper part of the right chassis frame 30. On the other hand, the wheelchair body 2 can be folded by removing the seat cushion 3 from the wheelchair body 2.

[0034] In this embodiment, the seat cushion 3 is detachably attached to the wheelchair body 2. Therefore, when the wheelchair 1 is not in use, the seat cushion 3 can be removed from the wheelchair body 2, allowing the wheelchair body 2 and the seat cushion 3 to be separated, making them lighter and easier to transport, as well as more compact. Furthermore, since the wheelchair body 2 is foldable, the wheelchair body 2 becomes more compact.

[0035] In other words, the link mechanism 40 comprises an upper link 41 and a lower link 42, and an upper connecting member 43 and a lower connecting member 44. The left chassis frame 20 includes a left link bracket 26 to which the upper link 41 and the lower link 42 are attached. The right chassis frame 30 also includes a right link bracket 36 to which the upper link 41 and the lower link 42 are attached. The left link bracket 26 and the right link bracket 36 are made of plate material or the like that extends in the vertical and front-rear directions.

[0036] The upper link 41 includes a left link component 41a and a right link component 41b. The left end of the left link component 41a of the upper link 41 is rotatably attached to the left link bracket 26 of the left chassis frame 20 around an axis extending in the front-rear direction. The right end of the right link component 41b of the upper link 41 is rotatably attached to the right link bracket 36 of the right chassis frame 30 around an axis extending in the front-rear direction. The right end of the left link component 41a and the left end of the right link component 41b are rotatably attached to the upper connecting member 43 around an axis extending in the front-rear direction.

[0037] The lower link 42 is a link positioned below the upper link 41, and like the upper link 41, it includes a left link component 42a and a right link component 42b. The left end of the left link component 42a of the lower link 42 is rotatably attached to the left link bracket 26 of the left chassis frame 20 around an axis extending in the front-rear direction. The right end of the right link component 42b of the lower link 42 is rotatably attached to the right link bracket 36 of the right chassis frame 30 around an axis extending in the front-rear direction. The right end of the left link component 42a and the left end of the right link component 42b of the lower link 42 are rotatably attached to the lower connecting member 44 around an axis extending in the front-rear direction. The left link component 42a of the lower link 42 has a predetermined inclination angle such that it is positioned lower as it moves to the right, and the right link component 42b has a predetermined inclination angle such that it is positioned lower as it moves to the left.

[0038] The upper connecting member 43 and the lower connecting member 44 are separate. A gripping portion 45 is attached to the upper connecting member 43. When the gripping portion 45 is lifted by hand, the upper connecting member 43 attempts to move upward, which pulls the right end of the left link component 41a and the left end of the right link component 41b of the upper link 41 upward. As a result, the left link component 41a pivots upward around the axis on the left chassis frame 20 side, and the right link component 41b pivots upward around the axis on the right chassis frame 30 side, causing the upper link 41 to fold upward so that it becomes convex.

[0039] Since the left link component 42a and the right link component 42b of the lower link 42 have a predetermined inclination angle, the left link component 42a swings downward with the axis on the left chassis frame 20 side as the pivot point, and the right link component 42b swings downward with the axis on the right chassis frame 30 side as the pivot point, causing the lower link 42 to fold so that it becomes convex downwards.

[0040] The folding operations of the upper link 41 and the lower link 42 are almost simultaneous. When the upper link 41 and the lower link 42 are folded, the left chassis frame 20 and the right chassis frame 30 are folded in a way that brings them close to each other in the vehicle width direction.

[0041] On the other hand, when a force is applied to the left chassis frame 20 and the right chassis frame 30, which are in a folded state, in a direction that separates them in the vehicle width direction, the left link component 41a of the upper link 41, which was convex upward, swings downward with the axis on the left chassis frame 20 side as the pivot point, and the right link component 41b swings downward with the axis on the right chassis frame 30 side as the pivot point, resulting in the upper link 41 becoming elongated in the left-right direction. The left link component 42a of the lower link 42, which was convex downward, swings upward with the axis on the left chassis frame 20 side as the pivot point, and the right link component 41b swings upward with the axis on the right chassis frame 30 side as the pivot point, resulting in the lower link 42 becoming elongated in the left-right direction.

[0042] The upper link 41 and the lower link 42 deploy almost simultaneously. When the upper link 41 and the lower link 42 deploy, the left chassis frame 20 and the right chassis frame 30 can be separated to their maximum extent in the vehicle width direction, resulting in the deployed state.

[0043] The structure of the link mechanism 40 is not limited to the structure described above, and any structure that can transition between a state in which the left chassis frame 20 and the right chassis frame 30 are close together in the vehicle width direction and an expanded state in which they are furthest apart in the vehicle width direction is acceptable. For example, the structure may be such that both the upper link 41 and the lower link 42 are bent upwards, or the structure may be such that both the upper link 41 and the lower link 42 are bent downwards.

[0044] As shown in Figure 6, a right-side recess 31a, which opens upward, is formed in a portion of the right upper edge portion 31 in the front-rear direction. The right-side recess 31a is continuous from near the rear end of the right upper edge portion 31 to the middle in the front-rear direction. Specifically, the right upper edge portion 31 has an outer embankment portion 33 that protrudes upward and extends in the front-rear direction on the outer side in the vehicle width direction, and an inner embankment portion 34 that protrudes upward and extends in the front-rear direction so as to be opposite the outer embankment portion 33 in the vehicle width direction on the inner side in the vehicle width direction. The outer embankment portion 33 is continuous from near the rear end of the right upper edge portion 31 to the middle in the front-rear direction. On the other hand, the rear end of the inner embankment portion 34 is set back from the rear end of the right upper edge portion 31, and a gap is created between the rear end of the inner embankment portion 34 and the rear end of the right upper edge portion 31. The outer embankment portion 33 extends further forward than the front end of the inner embankment portion 34. As a result, the front-to-back dimension of the inner embankment portion 34 is shorter than the front-to-back dimension of the outer embankment portion 33.

[0045] The right-side link bracket 36 is fastened below the inner ridge portion 34 on the right-side upper edge portion 31. The portion of the right-side upper edge portion 31 where the inner ridge portion 34 is formed has increased rigidity and strength because the inner ridge portion 34 functions like a rib. By fastening the right-side link bracket 36 to this portion with increased rigidity and strength, the mounting strength of the right-side link bracket 36 can be increased.

[0046] As shown in Figure 7, the height of the inner embankment 34 is lower than the height of the outer embankment 33, and the upper end of the outer embankment 33 is located above the upper end of the inner embankment 34. Furthermore, the left side of the outer embankment 33 (the inner side in the vehicle width direction) is the first inner surface 33a that faces the inner embankment 34. The first inner surface 33a is formed as an inclined surface that is positioned further outward in the vehicle width direction as it goes upward. In other words, the surface of the outer embankment 33 that faces the inner embankment 34 is inclined to be positioned further inward in the vehicle width direction as it goes downward.

[0047] Furthermore, the right side of the inner embankment portion 34 (outer side in the vehicle width direction) is a second inner side 34a that faces the first inner side 33a of the outer embankment portion 33 in the vehicle width direction. The second inner side 34a is formed as an inclined surface that slopes inward in the vehicle width direction as it goes upward.

[0048] The first inner surface 33a is inclined so that it is positioned further outward in the vehicle width direction as it goes upward, and the second inner surface 34a is inclined so that it is positioned further inward in the vehicle width direction as it goes upward. As a result, the distance between the first inner surface 33a and the second inner surface 34a in the vehicle width direction widens as it goes upward. In other words, the distance between the first inner surface 33a and the second inner surface 34a expands upward in the vehicle width direction. In this embodiment, the first inner surface 33a is inclined outward in the vehicle width direction and the second inner surface 34a is inclined inward in the vehicle width direction, but it is not limited to this, and the first inner surface 33a may be inclined and the second inner surface 34a may be formed as a vertical plane, or the second inner surface 34a may be inclined and the first inner surface 33a may be formed as a vertical plane.

[0049] As shown in Figure 8, the center of gravity G of the wheelchair occupant is located between the central axis 11d of the right drive wheel 11 and the front end of the right chassis frame 30. When a wheelchair occupant of standard build sits on the seat cushion 3, the anterior-posterior position of the center of gravity G is as shown in Figure 8. This center of gravity G is located in front of the central axis 11d of the right drive wheel 11 (central axis 10d of the left drive wheel 10) and behind the front end of the right chassis frame 30 (front end of the left chassis frame 20). Even if the wheelchair occupant's weight or build changes slightly, the center of gravity G of the wheelchair occupant will remain located between the central axis 11d of the right drive wheel 11 and the front end of the right chassis frame 30.

[0050] The longitudinal range of the outer embankment 33 and the inner embankment 34 includes the seated center of gravity G of the wheelchair occupant. That is, the outer embankment 33 has a long shape in the longitudinal direction, and in a side view, it extends both forward and backward of the seated center of gravity G of the wheelchair occupant. The inner embankment 34 also has a long shape in the longitudinal direction, and in a side view, it extends both forward and backward of the seated center of gravity G of the wheelchair occupant.

[0051] As shown in Figure 7, a bottom surface 35 extending in the vehicle width direction is formed between the lower part of the first inner surface 33a of the outer embankment 33 and the lower part of the second inner surface 34a of the inner embankment 34 on the right upper edge 31. This bottom surface 35 also extends in the front-rear direction.

[0052] As shown in Figure 9, the right upper edge portion 31 has a front end portion formed with a chassis-side inclined surface 31b that protrudes forward as it goes upward. The chassis-side inclined surface 31b is inclined so that it is located further forward as it goes upward with respect to the vertical plane, and further back as it goes downward, so that the front end portion of the right upper edge portion 31 has a shape that protrudes forward as it goes upward.

[0053] The right upper edge portion 31 has a rear end formed with an engagement recess 31c that is recessed toward the front and opens toward the rear. As will be described in detail later, the chassis-side inclined surface 31b and the engagement recess 31c of the right upper edge portion 31 are for fixing the right portion of the seat cushion 3 to the right upper edge portion 31.

[0054] As shown in Figure 6, the left upper edge portion 21 has a symmetrical structure with the right upper edge portion 31, and a left recess 21a opening upward is formed on a part of the left upper edge portion 21 in the front-rear direction. Furthermore, the left upper edge portion 21 has an outer embankment portion 23 that protrudes upward and extends in the front-rear direction on the outer part in the vehicle width direction, and an inner embankment portion 24 that protrudes upward and extends in the front-rear direction so as to be opposite the outer embankment portion 23 in the vehicle width direction on the inner part in the vehicle width direction. The front-rear dimension of the inner embankment portion 24 is shorter than the front-rear dimension of the outer embankment portion 23. The left link bracket 26 is fastened below the inner embankment portion 24 on the left upper edge portion 21. This increases the mounting strength of the left link bracket 26.

[0055] The height of the inner embankment 24 is lower than the height of the outer embankment 23. Furthermore, the longitudinal formation range of the outer embankment 23 and the inner embankment 24 includes the seated center of gravity G of the wheelchair occupant (shown in Figure 8). In addition, the left side of the outer embankment 23 (inner side in the vehicle width direction) is the first inner side 23a, which faces the inner embankment 24. The first inner side 23a is formed as an inclined surface that is positioned further outward in the vehicle width direction as you go upwards. Furthermore, the right side of the inner embankment 24 (outer side in the vehicle width direction) is the second inner side 24a, which faces the outer embankment 23. The second inner side 24a is formed as an inclined surface that is positioned further inward in the vehicle width direction as you go upwards. As a result, the distance between the first inner side 23a and the second inner side 24a increases upwards in the vehicle width direction. Alternatively, only the first inner surface 23a may be inclined and the second inner surface 24a may be formed as a vertical plane, or only the second inner surface 24a may be inclined and the first inner surface 23a may be formed as a vertical plane.

[0056] Between the lower part of the first inner surface 23a of the outer embankment 23 and the lower part of the second inner surface 24a of the inner embankment 24 on the left upper edge portion 21, a bottom portion 25 is formed that extends in the vehicle width direction and the front-rear direction.

[0057] As shown in Figure 6, the left upper edge portion 21 has a front end with a chassis-side inclined surface 21b that protrudes forward as it goes upward, and a rear end with an engaging recess 21c that is recessed toward the front and opens toward the rear. As will be described in detail later, the chassis-side inclined surface 21b and the engaging recess 21c of the left upper edge portion 21 are for fixing the left side portion of the seat cushion 3 to the left upper edge portion 21.

[0058] As shown in Figure 4, the seat cushion 3 comprises a seat surface 70, a seat back 71, a frame (cushion frame) 72 supporting the seat surface 70, a seat back member 73 supporting the seat back 71, and a hinge portion 74. The seat surface 70 is the part on which the wheelchair occupant sits, and is made of, for example, foam or fabric, forming a seat surface that extends in the front-to-back and left-to-right directions. The seat back 71 is the part that supports the area near the wheelchair occupant's waist, and is made of, for example, foam or fabric.

[0059] As shown in Figures 10, 11, and 12, the frame 72 has a pair of left and right vertical members 80 and 81, and a pair of front and rear transverse members 82 and 83 that connect the left and right vertical members 80 and 81 in the vehicle width direction. The left vertical member 80 is a member that extends in the front-rear direction at a position that overlaps with the left upper edge portion 21 in a plan view. The right vertical member 81 is a member that extends in the front-rear direction at a position that overlaps with the right upper edge portion 31 in a plan view. Since the left upper edge portion 21 and the right upper edge portion 31 are substantially parallel, the left vertical member 80 and the right vertical member 81 are also substantially parallel. The left vertical member 80 and the right vertical member 81 are designed to align with the left upper edge portion 21 and the right upper edge portion 31 from above when they are deployed.

[0060] The front transverse member 82 extends in the vehicle width direction below the front of the seat surface 70 and is a member that connects the left longitudinal member 80 to the front of the center in the longitudinal direction and the right longitudinal member 81 to the front of the center in the longitudinal direction. The rear transverse member 83 extends in the vehicle width direction below the rear of the seat surface 70 and is a member that connects the left longitudinal member 80 to the rear of the center in the longitudinal direction and the right longitudinal member 81 to the rear of the center in the longitudinal direction.

[0061] As shown in Figures 10 and 11, a downward-facing right-side protrusion 81a is formed on a portion of the lower part of the right-side longitudinal member 81 in the front-rear direction, matching the right-side recess 31a of the right-side upper edge portion 31. As shown in Figure 13, when mounted on the right-side chassis frame 30, the right-side protrusion 81a has a shape that tapers downwards in a front view, contacting the first inner surface 33a of the outer embankment portion 33 and the second inner surface 34a of the inner embankment portion 34 of the right-side upper edge portion 31. Specifically, the right side (outer surface in the vehicle width direction) 81b of the right-side protrusion 81a is formed as an inclined surface that follows the first inner surface 33a of the outer embankment portion 33, and is positioned further outward in the vehicle width direction as it goes upwards. The left side (inner surface in the vehicle width direction) 81c of the right-side protrusion 81a is formed as an inclined surface that follows the second inner surface 34a of the inner embankment portion 34, and is positioned further inward in the vehicle width direction as it goes upwards. The right side surface 81b of the right-side protrusion 81a abuts against the first inner surface surface 33a of the outer embankment 33, and the left side surface 81c of the right-side protrusion 81a abuts against the second inner surface surface 34a of the inner embankment 34. As the downward load acting on the frame 72 increases when a wheelchair user sits on the seat cushion 3, the right-side protrusion 81a of the right-side vertical member 81 makes strong contact with the first inner surface surface 33a of the outer embankment 33 and the second inner surface surface 34a of the inner embankment 34 due to the so-called wedge effect, eliminating any play. Furthermore, the left-right positioning of the right-side vertical member 81 with respect to the right upper edge 31 is achieved.

[0062] The lower surface portion 81d of the right-side protrusion 81a extends in the left-right and front-rear directions. When the right-side longitudinal member 81 is mounted on the right-side chassis frame, the lower surface portion 81d of the right-side protrusion 81a faces the bottom surface portion 35 of the recess 31a of the right-side upper edge portion 31 from above and is spaced upward from the bottom surface portion 35. As a result, when a wheelchair occupant is seated, the right-side protrusion 81a does not lift up from the first inner surface 33a of the outer embankment portion 33 or from the second inner surface 34a of the inner embankment portion 34, and the right-side protrusion 81a can be reliably brought into contact with both the first inner surface 33a and the second inner surface 34a.

[0063] When the seat cushion 3 is placed on the right chassis frame 30, the right protrusion 81a of the right vertical member 81 is inserted from above into the right recess 31a of the right upper edge 31 and fits together. In this state, the right vertical member 81 is formed to extend forward from the front end of the right upper edge 31 and cover its upper portion, and the portion extending forward from the front end of the right upper edge 31 is called the forward extension 81e. The forward extension 81e is used as a place for wheelchair occupants to rest their hands when getting in and out of the wheelchair.

[0064] As shown in Figures 10 and 11, the lower part of the left vertical member 80 has a symmetrical structure with the lower part of the right vertical member 81. That is, a downward-facing left protrusion 80a is formed on a part of the lower part of the left vertical member 80 in the front-rear direction, which matches the left recess 21a of the left upper edge 21. When mounted on the left chassis frame 20, the left protrusion 80a has a shape that tapers downwards in a front view, contacting the first inner surface 23a of the outer embankment 23 and the second inner surface 24a of the inner embankment 24 of the left upper edge 21. Specifically, although not shown, the left side (outer surface in the vehicle width direction) of the left protrusion 80a is formed as an inclined surface that is inclined along the first inner surface 23a of the outer embankment 23, and becomes further outward in the vehicle width direction as it goes upwards. The right side (inner side in the vehicle width direction) of the left protrusion 80a is formed as an inclined surface that follows the second inner side 24a of the inner embankment 24, and is positioned inward in the vehicle width direction as it goes upward. The right side of the left protrusion 80a abuts against the first inner side 23a of the outer embankment 23, and the left side of the left protrusion 80a abuts against the second inner side 24a of the inner embankment 24. As the downward load acting on the frame 72 increases when a wheelchair user sits on the seat cushion 3, the left protrusion 80a of the left vertical member 80 comes into strong contact with the first inner side 23a of the outer embankment 23 and the second inner side 24a of the inner embankment 24 due to the so-called wedge effect, eliminating any play. Furthermore, the left vertical member 80 is positioned in the left-right direction relative to the left upper edge 21.

[0065] The lower surface (not shown) of the left-side protrusion 80a extends in the left-right and front-rear directions. The lower surface of the left-side protrusion 80a of the left-side longitudinal member 80, when mounted on the left-side chassis frame 20, faces the bottom surface 25 (shown in Figure 6, etc.) of the recess 21a of the left-side upper edge 21 from above, and is spaced upward from the bottom surface 25. As a result, when a wheelchair occupant is seated, the left-side protrusion 80a does not lift up from the first inner surface 23a of the outer embankment 23 or from the second inner surface 24a of the inner embankment 24, and can be reliably brought into contact with both the first inner surface 23a and the second inner surface 24a.

[0066] When the seat cushion 3 is placed on the left chassis frame 20, the left protrusion 80a of the left vertical member 80 is inserted from above into the left recess 21a of the left upper edge 21 and fits together. In this state, the left vertical member 80 is formed to extend forward from the front end of the left upper edge 21 and cover its upper part, and the portion that extends forward from the front end of the left upper edge 21 is called the forward extension 80e. The forward extension 80e is used as a place for the wheelchair occupant to place their hands when getting in and out of the wheelchair.

[0067] In the right longitudinal member 81, an intermediate recess 81f is formed in the longitudinal middle section, into which the right inner embankment 34 fits, opening downward and inward in the vehicle width direction. As a result, the right longitudinal member 81 fits into the vehicle width direction inward of the right outer embankment 33. Similarly, in the left longitudinal member 80, an intermediate recess 80f is formed in the longitudinal middle section, into which the left inner embankment 24 fits, opening downward and inward in the vehicle width direction. As a result, the left longitudinal member 80 fits into the vehicle width direction inward of the left outer embankment 23. The front transverse member 82 connects the part of the right longitudinal member 81 in front of the intermediate recess 81f and the part of the left longitudinal member 80 in front of the intermediate recess 80f. The rear transverse member 83 connects the part of the right longitudinal member 81 in rear of the intermediate recess 81f and the part of the left longitudinal member 80 in rear of the intermediate recess 80f.

[0068] The seat cushion 3 is equipped with hinge portions 74 on the left and right sides, and seat back members 73 on the left and right sides, respectively. The left hinge portion 74 is located at the rear of the left vertical member 80, and the left seat back member 73 is supported by the left hinge portion 74 so as to be rotatable in the front-rear direction. The right hinge portion 74 is located at the rear of the right vertical member 81, and the right seat back member 73 is supported by the right hinge portion 74 so as to be rotatable in the front-rear direction.

[0069] As shown in Figure 14, the left and right hinge portions 74 each have a pivot axis 74a extending in the vehicle width direction. The pivot axis 74a is a component that constitutes the pivot point of the hinge portion 74. Figure 14 shows the seat back member 73 in the upright position, which is the position in which a wheelchair occupant can sit. By rotating the seat back member 73 in the upright position forward around the pivot axis 74a, it can be moved to the tilted-forward position as shown in Figure 15. The tilted-forward position is the position taken when removing the seat cushion 3 from the chassis frame 20, 30. By rotating the seat back member 73 in the tilted-forward position shown in Figure 15 upward around the pivot axis 74a, it can be moved to the upright position shown in Figures 14 and 16. In this way, the seat back member 73 is configured to be displaceable between the upright position and the tilted-forward position. Reference numeral 100, as shown in Figures 11 and 15, is an operating member for operating a locking mechanism (not shown) that locks the rotation of the hinge portion 74. When the seat back member 73 is moved to the upright position, the locking mechanism automatically locks, and when the seat back member 73 is moved to the forward-tilted position, the locking mechanism automatically locks. By operating the operating member 100, the locking mechanism can be released, so the locking mechanism is released before switching the seat back member 73 from the upright position to the forward-tilted position, and from the forward-tilted position to the upright position. The locking mechanism and operating member 100 may be provided as needed. Furthermore, the structure of the locking mechanism and operating member 100 may be any structure.

[0070] The seat cushion 3 also includes left and right claw portions 75. The left and right claw portions 75 are connected to the pivot point side of the hinge portion 74 on the left and right seat back members 73, respectively. The left claw portion 75 rotates in a direction toward and toward the rear end of the left upper edge portion 21 in accordance with the rotation of the left seat back member 73 (in the direction indicated by arrow A in Figure 15). Similarly, the right claw portion 75 rotates in a direction toward and toward the rear end of the right upper edge portion 31 in accordance with the rotation of the right seat back member 73. Since the left seat back member 73 and the right seat back member 73 are connected by a connecting member 78, the left and right claw portions 75 rotate simultaneously by the same amount. The rotation trajectories of the left and right claw portions 75 can be arbitrarily set by the structure of the hinge portion 74 and the relative positional relationship between the pivot axis 74a and the claw portion 75.

[0071] Specifically, the left hinge portion 74 is attached to the pivot point side (rotation axis 74a side) of the left seat back member 73, as well as the base end of the left claw portion 75. As shown in Figures 10 and 11, when the left seat back member 73 is in the upright position, the pivot point is positioned forward of the pivot point side of the left seat back member 73 and the base end of the left claw portion 75, while the left claw portion 75 is positioned rearward and downward of the pivot point. Also, as shown in Figure 15, when the left seat back member 73 is in the tilted-forward position, the left claw portion 75 is positioned above and rearward of the rear end of the left upper edge portion 21. The rotation trajectory of the left claw portion 75 is set such that, as the left seat back member 73 rotates from the tilted-forward position to the upright position, the left claw portion 75 moves downward while moving forward to enter and engage with the engagement recess 31c formed at the rear end of the left upper edge portion 21.

[0072] Similarly, on the right side, the pivot point side (rotation axis 74a side) of the right seat back member 73 is attached to the right hinge portion 74, as is the base end of the right claw portion 75. As shown in Figures 10 and 11, when the right seat back member 73 is in the upright position, the pivot point is positioned forward of the pivot point side of the right seat back member 73 and the base end of the right claw portion 75, while the right claw portion 75 is positioned rearward and downward of the pivot point. Also, as shown in Figure 15, when the right seat back member 73 is in the forward-folding position, the right claw portion 75 is positioned above and rearward of the rear end of the right upper edge portion 31. The rotational trajectory of the right claw portion 75 is set such that, as the right seat back member 73 rotates from the tilted forward position to the upright position, the right claw portion 75 moves downward and forward, entering and engaging with the engagement recess 21c formed at the rear end of the right upper edge portion 31.

[0073] As shown in Figure 16, a cushion-side inclined surface 81h is formed on the front lower part of the right vertical member 81, which matches the chassis-side inclined surface 31b formed at the front end of the right upper edge portion 31. The cushion-side inclined surface 81h is composed of an inclined surface that is positioned further back as it goes downwards. Therefore, the cushion-side inclined surface 81h has a shape that protrudes further back as it goes downwards, and becomes a surface that follows the chassis-side inclined surface 31b.

[0074] The same applies to the left side. As shown in Figure 11, a cushion-side inclined surface 80h is formed on the front lower part of the left vertical member 80, which matches the chassis-side inclined surface 21b formed at the front end of the left upper edge portion 21. The cushion-side inclined surface 80h is composed of an inclined surface that is positioned further back as it goes downwards. Therefore, the cushion-side inclined surface 80h has a shape that protrudes further back as it goes downwards, and becomes a surface that follows the chassis-side inclined surface 21b.

[0075] With the seat cushion 3 mounted on the chassis frames 20 and 30, as shown in Figure 16, the right chassis-side inclined surface 31b and the cushion-side inclined surface 81h are in contact and interlock. Since both the chassis-side inclined surface 31b and the cushion-side inclined surface 81h are inclined so that they are located further back as they go downwards, when the chassis-side inclined surface 31b and the cushion-side inclined surface 81h are interlocked, the right vertical member 81 cannot be moved upward relative to the right upper edge portion 31. In this state, when the seat back member 73 is moved to the upright position, the right claw portion 75 enters and engages with the engagement recess 31c of the right upper edge portion 31, thereby fixing the right vertical member 81 to the right upper edge portion 31. The mechanism including the hinge portion 74 and the claw portion 75 is the engagement mechanism B. In other words, the right vertical member 81 is provided with an engagement mechanism B that engages with a part of the right chassis frame 30 to fix the right vertical member 81 to the right chassis frame 30.

[0076] The same applies to the left side. When the seat cushion 3 is placed on the chassis frames 20 and 30, the left chassis-side inclined surface 21b (shown in Figure 6, etc.) and the cushion-side inclined surface 80h (shown in Figure 11, etc.) come into contact and interlock. Both the left chassis-side inclined surface 21b and the cushion-side inclined surface 80h are inclined so that they are positioned further back as they go downwards. Therefore, when the chassis-side inclined surface 21b and the cushion-side inclined surface 80h are interlocked, the left vertical member 80 cannot be moved upward relative to the left upper edge portion 21. In this state, when the seat back member 73 is placed in the upright position, the left claw portion 75 enters and engages with the engagement recess 21c of the left upper edge portion 21, thereby fixing the left vertical member 80 to the left upper edge portion 21. The mechanism including the left hinge portion 74 and the claw portion 75 is also an engagement mechanism B.

[0077] As shown in Figures 1 to 4, the wheelchair 1 is equipped with a left side guard 90 and a right side guard 91 to prevent the wheelchair user's body or clothing from coming into contact with the left and right drive wheels 10 and 11. The left side guard 90 and the right side guard 91 extend in the front-rear and up-down directions, respectively, and are made of, for example, resin material. When attaching the left side guard 90 and the right side guard 91, fastening members such as screws can be used.

[0078] The right-side guard 91 is provided on the inside of the right-side drive wheel 11 in the vehicle width direction and is a plate-shaped member that separates the rotation area of ​​the right-side drive wheel 11 from the upper area of ​​the seat cushion 3 in the vehicle width direction. As shown in Figures 14 and 16, the lower end of the right-side side guard 91 extends in the front-rear direction along the right-side longitudinal member 81 of the frame 72 of the seat cushion 3 and is fixed to the rear side of the forward extension portion 81e of the right-side longitudinal member 81. The right-side guard 91 extends upward from the portion fixed to the right-side longitudinal member 81, and as shown in Figure 8, the upper end of the right-side side guard 91 is above the upper surface of the seat surface 70 and reaches the height where the upper end of the outer circumference of the wheel 11a of the right-side drive wheel 11 is located, but is below the upper end of the outer circumference of the tire 11b of the right-side drive wheel 11.

[0079] The upper end of the right side guard 91 has a shape that corresponds to the outer edge of the right drive wheel 11 when viewed from the side. The right drive wheel 11 is positioned to the right of the seated wheelchair occupant, and the upper and front portion of the right drive wheel 11 is positioned to the right of the wheelchair occupant. The outer edge of the upper and front portion of the right drive wheel 11 is an arc shape that rises as it moves towards the rear, and the center of this arc shape is the central axis 11d. The edge portion of the right side guard 91 extending from the front end to the upper end according to this embodiment has an arc shape that substantially coincides with the outer edge of the right drive wheel 11. Alternatively, only the upper end of the right side guard 91 may have an arc shape that substantially coincides with the outer edge of the right drive wheel 11.

[0080] Here, the shape corresponding to the outer edge of the right drive wheel 11 may be the same arc shape as the outer edge of the right drive wheel 11, or an arc shape similar to the outer edge of the right drive wheel 11, or a triangular shape similar to the outer edge of the right drive wheel 11. If it is a triangular shape similar to the outer edge of the right drive wheel 11, the shape corresponding to the outer edge of the right drive wheel 11 is obtained by making it a triangle that is inclined so that the upper side is positioned higher as it goes towards the rear in a side view. Alternatively, the shape corresponding to the outer edge of the right drive wheel 11 may be a shape in which the upper end of the right side guard 91 is inclined so that it is positioned higher as it goes towards the rear.

[0081] As shown in Figure 14, a peripheral plate portion 91a is integrally molded along the edge of the right side guard 91, extending from the front end to the upper end, and projecting outward in the vehicle width direction. The formation of the peripheral plate portion 91a increases the rigidity of the right side guard 91 and makes the shape of the portion of the right side guard 91 extending from the front end to the upper end more clearly defined.

[0082] As shown in Figure 11, the left side guard 90 has a symmetrical structure with the right side guard 91. That is, the left side guard 90 is provided on the inside in the vehicle width direction of the left drive wheel 10 and is a plate-shaped member that separates the rotation area of ​​the left drive wheel 10 from the upper area of ​​the seat cushion 3 in the vehicle width direction. The lower end of the left side guard 90 extends in the front-rear direction along the left longitudinal member 80 of the frame 72 of the seat cushion 3 and is fixed to the rear side of the forward extension portion 80e of the left longitudinal member 80. The left side guard 90 extends upward from the portion fixed to the left longitudinal member 80. In addition, the upper end of the left side guard 90 has a shape that corresponds to the outer edge of the left drive wheel 10 when viewed from the side. Furthermore, a peripheral plate portion 90a is integrally molded on the edge portion extending from the front end to the upper end of the left side guard 90, projecting outward in the vehicle width direction and extending along the edge portion.

[0083] By shaping the upper ends of the left side guard 90 and the right side guard 91 to correspond to the outer edges of the left drive wheel 10 and the right drive wheel 11, respectively, it becomes easier to align the seat cushion 3 to a specific position before placing it on the chassis frames 20 and 30.

[0084] In this embodiment, as shown in Figure 16, both the chassis-side inclined surface 31b and the cushion-side inclined surface 81h are inclined so that they are located further back as they go downwards (the same applies to the left side). Therefore, when attaching the seat cushion 3 to the chassis frames 20 and 30, the right vertical member 81 of the seat cushion 3 must be temporarily placed in a position forward of the mounting position (the position shown by the solid line in Figure 16), as shown by the dashed line in Figure 16 (the same applies to the left vertical member 80). When viewed from above, the chassis-side inclined surface 31b, the recess 31a, the cushion-side inclined surface 81h, the right protrusion 81a, etc. are hidden by the seat cushion 3. Therefore, it is difficult to align the seat cushion 3 to a specific front-to-back position while viewing the chassis-side inclined surface 31b, the recess 31a, the cushion-side inclined surface 81h, the right protrusion 81a, etc. from above.

[0085] In contrast, in this embodiment, the left side guard 90 and the right side guard 91 are fixed to the vertical members 80 and 81 of the seat cushion 3, respectively, and the upper ends of the left side guard 90 and the right side guard 91 have shapes corresponding to the outer edges of the left drive wheel 10 and the right drive wheel 11, respectively. Therefore, when attaching the seat cushion 3 to the wheelchair body 2, even a person who does not know the specific front-to-back position will naturally try to place the seat cushion 3 on the chassis frame 20 and 30 so that the upper ends of the side guards 90 and 91 align with the outer edges of the wheels 10 and 11. Since the position where the upper ends of the side guards 90 and 91 align with the outer edges of the wheels 10 and 11 is a specific front-to-back position, it becomes possible to easily place the seat cushion 3 on the chassis frame 20 and 30 at that specific front-to-back position without looking from below. After placing the seat cushion 3 on the chassis frames 20 and 30, it is shifted slightly backward so that the right-side convex portion 81a fits into the recess 31a, as shown by the solid line in Figure 16, and the right-side vertical member 81 moves downward until it is in its proper mounting position (the same applies to the left side). Then, when the seat back member 73 of the seat cushion 3 is rotated to the upright position, the left and right claw portions 75, 75 enter and engage with the engagement recesses 21c, 31c respectively, and the seat cushion 3 is fixed to the chassis frames 20 and 30.

[0086] To remove the seat cushion 3 from the chassis frames 20 and 30, the seat back member 73, which is in the upright position, is rotated to the forward-tilted position. This causes the left and right claws 75 to disengage from the engagement recesses 21c and 31c, detaching it from the chassis frames 20 and 30. Then, as shown by the dashed lines in Figure 16, the seat cushion 3 is lifted diagonally forward, detaching it from the chassis frames 20 and 30. After this, the wheelchair body 2 can be folded.

[0087] The embodiments described above are merely illustrative in all respects and should not be interpreted restrictively. Furthermore, any modifications or changes that fall within the equivalent scope of the claims are all within the scope of the present invention. [Industrial applicability]

[0088] As explained above, the wheelchair relating to this disclosure can be used, for example, when the seat cushion and chassis can be separated. [Explanation of Symbols]

[0089] 1 Wheelchair 2. Wheelchair chassis 3 Seat cushions 10, 11 Drive wheels 20 Left side chassis frame 21 Upper left side 26 Link Bracket 30 Right-side chassis frame 31 Right upper edge 31b Chassis-side inclined surface 33 Outer bank 33a 1st inner surface 34 Inner embankment 34a 2nd inner surface 35 Bottom part 31 Right upper edge 31c Engagement recess 40 Link mechanism 73 Seat back member 74 Hinge section 75 Claw part 80, 81 vertical members 81d Bottom part 81h Cushion side slope 82, 83 Horizontal members 90, 91 Side Guard 90a, 91a Circumferential plate part B Engagement mechanism

Claims

1. A wheelchair comprising a pair of left and right chassis frames that pivotally support the wheels outward in the width direction of the vehicle, and a separate seat cushion that is mounted on the left and right chassis frames at a specific front-rear position, The chassis frame has a pair of left and right cushion mounting members that extend in the front-rear direction at a position close to the inside of the left and right wheels, The cushion mounting member has a front end with a chassis-side inclined surface that protrudes forward as it goes upward, and a rear end with an engagement recess that is recessed toward the front. The seat cushion comprises a pair of left and right vertical members extending in the front-rear direction at a position overlapping the cushion mounting member in a plan view, a seat back member supported so as to be rotatable in the front-rear direction by hinge portions provided at the rear of the left and right vertical members and displaceable between an upright position and a forward-tilted position, and a claw portion connected to the pivot point side of the hinge portion on the seat back member and rotating in a direction toward and toward the rear end of the cushion mounting member in accordance with the rotation of the seat back member. A cushion-side inclined surface is formed on the lower front side of the longitudinal member, which matches the chassis-side inclined surface and protrudes further rearward as it goes downward. A wheelchair in which, when the seat cushion is mounted on the chassis frame, the chassis-side inclined surface and the cushion-side inclined surface interlock, and when the seat back member is in the upright position, the claw portion enters and engages with the engagement recess of the cushion mounting member, and the vertical member is fixed to the cushion mounting member.

2. In the wheelchair according to claim 1, The outer portion of the cushion mounting member in the vehicle width direction is provided with an outer embankment portion that protrudes upward and extends in the front-rear direction. The aforementioned vertical member is a wheelchair that fits into the inner side of the outer embankment in the vehicle width direction.

3. In the wheelchair according to claim 1, The hinge portion is to which the pivot point side of the seat back member is attached, and the base end of the claw portion is also attached. A wheelchair in which, when the seat back member is in the upright position, the pivot point is positioned forward of the pivot point side of the seat back member and the base end of the claw portion.

4. In the wheelchair described in claim 3, A wheelchair in which, when the seat back member is in the upright position, the claw portion is positioned rearward and downward from the pivot point.

5. In the wheelchair according to claim 4, When the seat back member is in the forward-folding position, the claw portion is positioned above and behind the rear end of the cushion mounting member. A wheelchair in which, as the seat back member rotates from a tilted forward position to an upright position, the rotational trajectory of the claw portion is set such that the claw portion moves downward while simultaneously moving forward and entering the engagement recess.

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