Wheelchair

Abstract

To enable a seat to be easily attached and prevent rattling of the seat after attachment.SOLUTION: A wheelchair includes a foldable support arm connecting a left side frame and a right side frame. A seat includes a seat frame configured to be attachable to and detachable from the left side frame and the right side frame. The seat frame is provided with a sandwiching part 100 sandwiching at least one of the left side frame and the right side frame from a horizontal direction.SELECTED DRAWING: Figure 21

Description

[Technical field]

[0001] The present disclosure relates to a foldable wheelchair that is configured to be foldable. [Background technology]

[0002] Generally, a folding wheelchair that can be folded when not in use is known (see, for example, Patent Document 1). In the wheelchair of Patent Document 1, a left support arm is rotatably connected to a left side frame to which a left drive wheel is attached, and a right support arm is rotatably connected to a right side frame to which a right drive wheel is attached. When changing from a folded state to an unfolded state, the left support arm and the right support arm are rotated backward, thereby narrowing the space between the left side frame and the right side frame, making the wheelchair compact.

[0003] In the wheelchair of Patent Document 1, the seat needs to be removed from the left and right side frames before folding, so the seat is detachable from both side frames. Specifically, the seat is fixed to both side frames by inserting pins protruding forward from the seat frame into insertion holes formed in both side frames, while the seat can be removed from both side frames by retracting the pins. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2022-114838 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, when adopting a structure in which a pin extending from the seat frame is inserted into an insertion hole in the side frame as in Patent Document 1, it is necessary to switch the pin from a retracted position to an extended position when installing the seat, which makes installing the seat time-consuming.

[0006] In addition, the outer diameter of the pin must be smaller than the inner diameter of the insertion hole in order to insert it smoothly, but if the outer diameter of the pin is smaller than the inner diameter of the insertion hole, there is a problem that the seat will be more likely to rattle against the side frame.

[0007] The present disclosure has been made in consideration of the above points, and has an object to make it possible to easily install a seat and to suppress rattling of the seat after installation. [Means for solving the problem]

[0008] In order to achieve the above object, a first aspect of the present disclosure can be premised on a foldable wheelchair equipped with a seat on which a wheelchair user can sit. The wheelchair includes a left side frame that supports a drive wheel on the left side of the vehicle body, a right side frame that supports a drive wheel on the right side of the vehicle body, and a foldable support arm that connects the left side frame and the right side frame. The seat has a seat frame that is configured to be detachable from the left side frame and the right side frame. The seat frame is provided with a clamping portion that clamps at least one of the left side frame and the right side frame from the left and right directions.

[0009] According to this configuration, when the seat frame is attached to the side frame, the side frame is clamped in the left-right direction by the clamping portion of the seat frame, so there is no need to switch the pin from the retracted state to the advanced state as in the conventional case, making it easier to attach the seat. In addition, because the side frame is clamped in the left-right direction by the clamping portion of the seat frame, play is unlikely to occur between the seat frame and the side frame, suppressing rattling of the seat.

[0010] The clamping portion according to the second aspect of the present disclosure may be configured as a part of the seat frame, and may have a frame abutment portion that abuts against one of the side frames from one side in the left-right direction, an abutment member that abuts against the one of the side frames from the other side in the left-right direction, a first biasing member that biases the abutment member in a direction in which the abutment member abuts against the one of the side frames, and a locking portion that locks the abutment member in a state in which the abutment member abuts against the one of the side frames. In this case, the locking portion may be connected to an unlocking operation portion provided in a seat back portion of the seat via an operation wire.

[0011] According to this configuration, the abutment member is locked in a state of abutment against the side frame by the biasing force of the first biasing member, so that the seat is firmly fixed to the side frame. On the other hand, when removing the seat, the unlocking operation part is operated, and the operating force is transmitted to the locking part via the operating wire, so that the locking can be released. At this time, since the unlocking operation part is provided in the seat back part, which is located higher than the seat cushion part, operability is good.

[0012] The locking portion according to a third aspect of the present disclosure may have a locking pin that is inserted into a hole of the abutting member in a state supported by the seat frame, and a second biasing member that biases the locking pin in a direction of insertion into the hole. A guide surface that guides the locking pin into the hole may be provided on an inner surface of the hole.

[0013] According to this configuration, the lock pin biased by the second biasing member is guided into the hole by the guide surface, so that the lock pin can be reliably inserted into the hole to lock the abutment member.

[0014] The operating wire according to the fourth aspect of the present disclosure may be connected to the lock pin. The lock pin and the second biasing member may be disposed on the vehicle body rear side of the abutment member.

[0015] According to this configuration, the lock pin can be positioned relatively far back, so that the lock pin and the unlocking operation part can be brought closer together, which makes it possible to shorten the length of the operation wire and makes it easier to handle the operation wire, improving operability when unlocking.

[0016] A recess may be provided on a side surface of the one side frame in the front-rear direction middle portion according to the fifth aspect of the present disclosure. In this case, the abutment member may have a fitting portion that fits into the recess.

[0017] According to this configuration, by fitting the fitting portion of the abutment member into the recess of the side frame, it is possible to position the seat frame in the fore-aft direction relative to the side frame, thereby preventing the seat frame from shifting when getting in.

[0018] The contact member according to the sixth aspect of the present disclosure may be disposed on the inner side of the seat frame in the vehicle width direction.

[0019] That is, since the abutment member is a member that moves in the vehicle width direction (left and right direction) when the seat frame is installed, it may be vulnerable to external impacts. According to this configuration, by arranging the abutment member on the inside of the seat frame in the vehicle width direction, it is less likely for objects to hit the abutment member from the outside compared to when the abutment member is arranged on the outside in the vehicle width direction, and as a result, damage to the abutment member can be suppressed. Effect of the Invention

[0020] As described above, since the seat frame is provided with the clamping portions that clamp the side frames from the left and right, the seat can be easily installed and rattling of the seat after installation can be suppressed. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a perspective view of a wheelchair according to an embodiment of the present invention, seen from the front. [Diagram 2]FIG. 2 is a perspective view of the wheelchair from the front with the seat removed. [Diagram 3] FIG. 3 is a front view of the wheelchair with the seat removed. [Figure 4] FIG. 4 is a left side view of the seat. [Diagram 5] FIG. 5 is a perspective view of the folded wheelchair body seen from above. [Figure 6] FIG. 6 is a front view of the folded wheelchair body. [Figure 7] FIG. 7 is a right side view of the left side frame. [Figure 8] FIG. 8 is a left side view of the right side frame. [Figure 9] FIG. 9 is an enlarged plan view showing the footrest, the rod, the support arm and their surroundings in the deployed state. [Figure 10] FIG. 10 is a cross-sectional view corresponding to the line XX in FIG. [Figure 11] FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. [Figure 12] FIG. 12 is a view equivalent to FIG. 10, showing the wheelchair main body in a folded state. [Figure 13] FIG. 13 is a perspective view of the wheelchair body in a folded state as seen from the left side, with the left side frame and wheels omitted. [Figure 14] FIG. 14 shows the wheelchair body in a folded state as viewed from the left side, with the left side frame and wheels omitted. [Figure 15] FIG. 15 is a diagram showing the positional relationship of each arm component in the deployed state. [Figure 16] FIG. 16 is a diagram showing the positional relationship of each arm component member in the folded state. [Figure 17] FIG. 17 is a front view showing the lower arm component and the engaged plate in the deployed state. [Figure 18] FIG. 18 is a rear view of the engagement portion attached to the upper connecting member. [Figure 19] FIG. 19 is a plan view of the sheet. [Figure 20] FIG. 20 is a rear view of the seat. [Figure 21] FIG. 21 is a cross-sectional view corresponding to the line XXI-XXI in FIG. [Figure 22] FIG. 22 is a diagram of the left frame portion of the seat frame as viewed from above, showing a partial cross section. [Diagram 23] FIG. 23 is a view of a part of the seat back portion seen from the rear. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. Note that the following description of the preferred embodiments is merely illustrative in nature and is not intended to limit the present invention, its applications, or its uses.

[0023] Fig. 1 is a perspective view of a wheelchair 1 according to an embodiment of the present invention, seen obliquely from above and ahead. As shown in Figs. 2 and 3, this wheelchair 1 is configured so that the seat 3 can be removed from the wheelchair body 2 without the need for tools. Fig. 4 is a left side view of the seat 3 removed from the wheelchair body 2. Furthermore, the wheelchair body 2 with the seat 3 removed is configured so as to be foldable, as shown in Figs. 5 and 6, and therefore the wheelchair 1 according to this embodiment is a foldable wheelchair on which a wheelchair user can sit.

[0024] In the description of this embodiment, the direction of travel of the wheelchair 1 when moving forward is simply referred to as "front," and the front of the wheelchair 1 corresponds to the front of the wheelchair user (not shown) seated in the wheelchair 1. 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 body. The left side of the wheelchair user seated in the wheelchair 1 is the left side of the body of the wheelchair 1, and is simply referred to as "left." The right side of the wheelchair user seated in the wheelchair 1 is the right side of the 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 body, and is also referred to as the width direction of the body. The "upper side" of the wheelchair 1 is the side that is the top when placed on a horizontal surface in a seatable state, and the "lower side" of the wheelchair 1 is the side that is the bottom when placed on a horizontal surface in a seatable state.

[0025] (Structure of the wheelchair body) As shown in Figures 1 and 2, the wheelchair body 2 includes left and right drive wheels 10, 11, left and right casters 12, 13, left and right side frames 20, 30, upper and lower support arms 40, 50, and a footrest 60. The left drive wheel 10 is journaled on the left side frame 20, and the right drive wheel 11 is journaled on the right side frame 30. The left side frame 20 and the right side frame 30 are connected by an upper support arm 40 and a lower support arm 50. By folding the upper support arm 40, the lower support arm 50, and the footrest 60, the wheelchair 1 can be folded as shown in Figures 5 and 6.

[0026] The driving wheels 10, 11 are large-diameter wheels that a wheelchair user seated on the seat 3 can hold by hand and rotate forward or backward. They can also be called driving rear wheels because they are provided on the rear side of the wheelchair body 2. The structure of the driving wheels 10, 11 is not particularly limited, but in this embodiment, they are configured such that rubber tires 10b, 11b are attached to wheels 10a, 11a molded from carbon fiber reinforced plastics (CFRP). Hand rims 10c, 11c are provided on the outer sides of the wheels 10a, 11a in the vehicle width direction, respectively, for the wheelchair user to hold by hand when driving. Although not shown, the wheelchair 1 is provided with a brake. The brake is configured to be operated by the hand of a wheelchair user seated on the seat 3, and specifically, it generates a braking force by contacting the tires 10b, 11b. Such a brake is conventionally well known.

[0027] The casters 12, 13 are wheels for changing the direction of travel of the wheelchair 1, and have a smaller diameter than the drive wheels 10, 11. The casters 12, 13 are provided on the front side of the wheelchair body 2, and therefore can also be called front wheels for changing the direction of travel.

[0028] (Side frame configuration) As shown in Fig. 2, the left side frame 20 includes an upper frame portion 21 extending in the front-rear direction, and a caster support portion 22. Fig. 7 shows the left side frame 20 when the wheelchair 1 is placed on a horizontal surface, and as shown in this figure, the upper frame portion 21 is gently inclined so that it is positioned higher as it goes forward. The inclination angle of the upper frame portion 21 does not have to be the angle shown in the figure, and it may be horizontal. The upper frame portion 21 and the caster support portion 22 are integrally molded from the above-mentioned CFRP, and therefore the left side frame 20 is composed of a single part. The left side frame 20 may be composed of a metal material, or may be composed by joining multiple parts.

[0029] An axle insertion hole 21a into which the right side of the axle 10d (shown in FIG. 1) of the left driving wheel 10 is inserted and fixed is formed at the rear end of the upper frame portion 21. With the right side of the axle 10d fixed to the rear end of the upper frame portion 21, the left driving wheel 10 is journaled so as to be rotatable about an axis extending in the left-right direction relative to the left side frame 20.

[0030] A concave left seat frame accommodating portion 21b is formed on the right side of the upper frame portion 21 to accommodate the rear portion of the left frame portion 93 (shown in phantom lines) of the seat 3. The left seat frame accommodating portion 21b is formed continuously in the front-rear direction in a portion of the upper frame portion 21 excluding the rear end portion. The left seat frame accommodating portion 21b is open upward and to the right, and also toward the front, so that the rear portion of the left frame portion 93 can be accommodated from above.

[0031] As shown by an imaginary line in Fig. 7, a front portion of the left frame portion 93 is disposed so as to protrude forward from the left seat frame accommodation portion 21b. The upper frame portion 21 is provided with a seat support plate portion 23 for supporting a front-rear middle portion of the left frame portion 93 from below. The seat support plate portion 23 has a long and narrow plate shape extending forward, and constitutes a part of the left side frame 20. The front end portion of the seat support plate portion 23 is located rearward of the front end portion of the left frame portion 93. A recess 23a is provided on the right side surface (inner surface in the vehicle width direction) of the front-rear middle portion of the seat support plate portion 23.

[0032] The left side frame 20 has an arm connecting member 24. The arm connecting member 24 is fixed to a right side surface (a surface located inside in the vehicle width direction) of the left side frame 20 in the front-rear direction middle portion, and is a member to which the left end portions of the upper support arm 40 and the lower support arm 50 are connected. An upper protruding plate portion 24a extending in the vertical direction is provided on the upper side of the arm connecting member 24 so as to protrude toward the right side. An upper through hole 24b penetrating in the front-rear direction is formed in the upper protruding plate portion 24a. A lower protruding plate portion 24c extending in the vertical direction is provided on the lower side of the arm connecting member 24 so as to protrude toward the right side. The lower protruding plate portion 24c is located rearward of the upper protruding plate portion 24a. A lower through hole 24d penetrating in the front-rear direction is formed in the lower protruding plate portion 24c.

[0033] The caster support part 22 is formed so as to extend forward and to be positioned lower as it approaches the front end. A caster mounting part 22a, to which the left caster 12 is attached so as to be rotatable about an axis extending in the vertical direction, is provided at the front end part of the caster support part 22 so as to protrude downward. Furthermore, a footrest support part 22b, which supports a footrest described later, is provided at the front end part of the caster support part 22 so as to protrude downward. As shown in FIG. 3, the footrest support part 22b is located to the right (inner in the vehicle width direction) of the caster mounting part 22a.

[0034] The right side frame 30 has a shape that is bilaterally symmetrical to the left side frame 20. That is, the right side frame 30 includes an upper frame portion 31 and a caster support portion 32, as shown in FIG.

[0035] An axle insertion hole 31a into which the left end of the axle 11d (shown in FIG. 11) of the right driving wheel 11 is inserted and fixed is formed at the rear end of the upper frame portion 31 of the right side frame 30. With the left end of the axle 11d fixed to the rear end of the upper frame portion 31, the right driving wheel 11 is journaled so as to be rotatable about an axis extending in the left-right direction relative to the right side frame 30.

[0036] A concave right seat frame accommodating portion 31b is formed on the left side of the upper frame portion 31 of the right side frame 30 to accommodate a rear portion of a right frame portion 94 (shown in phantom lines) of the seat 3. The right seat frame accommodating portion 31b is formed continuously in the front-rear direction in a portion of the upper frame portion 31 excluding the rear end portion. The right seat frame accommodating portion 31b is open upward and leftward, and is also open toward the front, so that the rear portion of the right frame portion 94 can be accommodated from above.

[0037] As shown by an imaginary line in Fig. 8, a front portion of the right frame portion 94 is disposed so as to protrude forward from the right seat frame accommodation portion 31b. The upper frame portion 31 is provided with a seat support plate portion 33 for supporting a front-rear intermediate portion of the right frame portion 94 from below. The seat support plate portion 33 has a long and narrow plate shape extending forward, and constitutes a part of the right side frame 30. The front end portion of the seat support plate portion 33 is located rearward of the front end portion of the right frame portion 94. A recess 33a is provided on the left side surface of the front-rear intermediate portion of the seat support plate portion 33.

[0038] The right side frame 30 has an arm connecting member 34. The arm connecting member 34 is fixed to a left side surface (a surface located inside in the vehicle width direction) of the right side frame 30 in the front-rear direction middle portion, and is a member to which the right end portions of the upper support arm 40 and the lower support arm 50 are connected. An upper protruding plate portion 34a extending in the vertical direction is provided on the upper side of the arm connecting member 34 so as to protrude toward the left side. An upper through hole 34b penetrating in the front-rear direction is formed in the upper protruding plate portion 34a. A lower protruding plate portion 34c extending in the vertical direction is provided on the lower side of the arm connecting member 34 so as to protrude toward the left side. The lower protruding plate portion 34c is located rearward of the upper protruding plate portion 34a. A lower through hole 34d penetrating in the front-rear direction is formed in the lower protruding plate portion 34c.

[0039] The caster support part 32 of the right side frame 30 is formed so as to extend forward and to be positioned lower as it approaches the front end. A caster attachment part 32a is provided at the front end part of the caster support part 32 so as to protrude downward, to which the right caster 13 is attached so as to be rotatable about an axis extending in the vertical direction. Furthermore, a footrest support part 32b is provided at the front end part of the caster support part 32 so as to protrude downward, to support a footrest, which will be described later. As shown in FIG. 3, the footrest support part 32b is located to the left of the caster attachment part 32a (inner in the vehicle width direction).

[0040] (Footrest configuration) 1, a footrest 60 on which a wheelchair user seated on the seat 3 places his / her feet is provided at the front of the wheelchair body 2. The footrest 60 connects the footrest support part 22b, which is the front end part of the left side frame 20, and the footrest support part 32b, which is the front end part of the right side frame 30, and is configured to be foldable at the center in the left-right direction.

[0041] That is, the footrest 60 has a three-part structure and includes a left footrest component member 61 that constitutes the left side of the footrest 60, a right footrest component member 62 that constitutes the right side of the footrest 60, and a bracket 63 that rotatably connects the right end of the left footrest component member 61 and the left end of the right footrest component member 62. The bracket 63 is disposed in the center of the footrest 60 in the left-right direction. The left footrest component member 61 and the right footrest component member 62 are made of plate material, and the left footrest component member 61 and the right footrest component member 62 form a plate-shaped foot rest portion that extends in the left-right direction.

[0042] 9 shows a plan view of the footrest 60. A left connecting shaft 22c extending in the front-rear direction is supported on the left footrest support part 22b. The left end part of the left footrest component 61 is connected to the left footrest support part 22b via the left connecting shaft 22c. The left footrest component 61 is rotatable in the up-down direction around the axis of the left connecting shaft 22c. The left connecting shaft 22c may rotate relative to the footrest support part 22b, or the left footrest component 61 may rotate relative to the left connecting shaft 22c.

[0043] A right connecting shaft 32c extending in the front-rear direction is supported on the right footrest support part 32b in the same manner as on the left side. The right end part of the right footrest component 62 is connected to the right footrest support part 32b via the right connecting shaft 32c. The right footrest component 62 is rotatable in the up-down direction around the axis of the right connecting shaft 32c.

[0044] A left cutout 61a is formed in the center in the front-rear direction at the right end of the left footrest component member 61. A right cutout 62a is also formed in the center in the front-rear direction at the left end of the right footrest component member 62. The left cutout 61a and the right cutout 62a are positioned in the same position in the front-rear direction, and therefore an opening 64 is formed between the right end of the left footrest component member 61 and the left end of the right footrest component member 62 by both cutouts 61a, 62a.

[0045] A first connecting shaft 63a extending in the front-rear direction is supported on the left side of the bracket 63. A right end of the left footrest component 61 is rotatably connected to the bracket 63 via the first connecting shaft 63a. A second connecting shaft 63b extending in the front-rear direction is supported on the right side of the bracket 63. A left end of the right footrest component 62 is rotatably connected to the bracket 63 via the second connecting shaft 63b.

[0046] When the footrest 60 is unfolded, the bracket 63 is disposed in an opening 64 formed between the right end of the left footrest component 61 and the left end of the right footrest component 62. When the footrest 60 is unfolded, the bracket 63 is sandwiched between the left footrest component 61 and the right footrest component 62. Specifically, the left end of the bracket 63 is formed to abut against the edge of the left cutout 61a of the left footrest component 61 when the footrest 60 is unfolded. Also, the right end of the bracket 63 is formed to abut against the edge of the right cutout 62a of the right footrest component 62 when the footrest 60 is unfolded.

[0047] In this way, the footrest 60 has a three-part structure, the left footrest component 61 is connected to the footrest support 22b so as to be rotatable in the vertical direction, the right footrest component 62 is connected to the footrest support 32b so as to be rotatable in the vertical direction, and the bracket 63 is connected to the left footrest component 61 and the right footrest component 62 so as to be rotatable relative to each other, so that it is possible to switch from the unfolded state (usable state) shown in FIG. 1 etc. to the folded state (unusable state) shown in FIG. 5 etc., and vice versa. When switching from the unfolded state to the folded state, the left footrest component 61 and the right footrest component 62 are rotated upward so that the footrest 60 has a shape that forms a convex shape facing upward. When switching from the folded state to the unfolded state, the left footrest component 61 and the right footrest component 62 are rotated downward so as to assume a posture that extends in the left-right direction. In other words, the folding and unfolding directions of the footrest 60 are vertical, so that the footrest 60 does not hinder the folding and unfolding of the wheelchair 1.

[0048] The rear end of the bracket 63 protrudes upward beyond the upper surfaces of the left footrest component 61 and the right footrest component 62, and a third connecting shaft 63c extending in the left-right direction is supported on this upward protruding portion. The third connecting shaft 63c is a member for connecting the lower end of a rod 85 (described later) to the bracket 63.

[0049] (Structure of upper and lower support arms) The wheelchair body 2 is configured so that it can be changed from the unfolded state shown in Figures 1 to 3 to the folded state shown in Figures 5 and 6, and from the folded state to the unfolded state, without using tools or the like. In the unfolded state, the gap between the left side frame 20 and the right side frame 30 is widened, making it possible to attach the seat 3. On the other hand, in the folded state, the gap between the left side frame 20 and the right side frame 30 is narrowed, making it impossible to attach the seat 3.

[0050] In this embodiment, the seat 3 is configured to be detachable from the wheelchair body 2, so that when the wheelchair 1 is not in use, the seat 3 can be removed from the wheelchair body 2 to separate the wheelchair body 2 and the seat 3, making the wheelchair lighter and more compact to carry. In addition, the wheelchair body 2 is foldable, so the wheelchair body 2 becomes compact. Below, the upper support arm 40 and the lower support arm 50 will be described in detail as the structure that allows the wheelchair body 2 to be foldable.

[0051] As shown in Figures 10 to 14, the upper support arm 40 is made up of multiple members, connects the left side frame 20 and the right side frame 30, and is folded up and down at the center in the left-right direction (longitudinal direction). The lower support arm 50 connects the left side frame 20 and the right side frame 30, and is folded up and down at the center in the left-right direction (longitudinal direction), and is provided below the upper support arm 40. The lower support arm 50 is also made up of multiple members. The number of support arms is not limited to two.

[0052] 10, the upper support arm 40 is configured to extend in the left-right direction when in the unfolded state. The upper support arm 40 is located immediately below the seat 3, but since the upper support arm 40 extends in a substantially horizontal direction, it does not interfere with the cushion portion of the seat 3 when the user is seated. The upper support arm 40 has a first upper arm component 41 that constitutes the left side of the upper support arm 40, a second upper arm component 42 that constitutes the right side of the upper support arm 40, and an upper connecting member 43 that rotatably connects the right end of the first upper arm component 41 and the left end of the second upper arm component 42.

[0053] The lower support arm 50 is configured so that it is positioned higher toward the left end and the right end when in the deployed state. In other words, the left-right center of the lower support arm 50 is shaped to protrude downward compared to both ends, but since there is a gap between the left and right drive wheels 10, 11, this does not cause a problem during use. The lower support arm 50 has a first lower arm component 51 constituting the left side of the lower support arm 50, a second lower arm component 52 constituting the right side of the lower support arm 50, and a lower connecting member 53 that rotatably connects the right end of the first lower arm component 51 and the left end of the second lower arm component 52. The first lower arm component 51 is inclined so that the right end of the first lower arm component 51 is positioned lower than the left end, and the second lower arm component 52 is inclined so that the left end of the second lower arm component 52 is positioned lower than the right end.

[0054] 15 shows the positional relationship when the first upper arm component 41 and the second upper arm component 42, and the first lower arm component 51 and the second lower arm component 52 are in the deployed state. As shown in this figure, when viewed from the back (the same applies when viewed from the front), the distance between the upper support arm 40 and the lower support arm 50 becomes wider toward the center in the left-right direction, but becomes narrower toward the left and right ends.

[0055] The left end of the first upper arm component 41 is connected to the upper protruding plate portion 24a of the arm connecting member 24 of the left side frame 20 via the upper first support shaft 41a. The upper first support shaft 41a extends in the front-rear direction and is supported in a state where it is inserted into the upper through-hole 24b. The upper first support shaft 41a is rotatable about an axis relative to the left end of the first upper arm component 41, or is rotatable about an axis relative to the upper protruding plate portion 24a. In other words, the left end of the first upper arm component 41 is connected to the left side frame 20 so as to be rotatable about an axis extending in the front-rear direction.

[0056] The left and right ends of the first upper arm component 41 are the left and right ends when in the unfolded state, and are the lower and upper ends, respectively, when in the folded state. Similarly, the left and right ends of the second upper arm component 42 are the left and right ends when in the unfolded state, and are the upper and lower ends, respectively, when in the folded state.

[0057] The right end of the second upper arm component 42 is connected to the upper protruding plate portion 34a of the arm connecting member 34 of the right side frame 30 via the upper second support shaft 42a. The upper second support shaft 42a extends in the front-rear direction and is supported in a state where it is inserted into the upper through-hole 34b. The upper second support shaft 42a is rotatable about an axis relative to the right end of the second upper arm component 42, or is rotatable about an axis relative to the upper protruding plate portion 34a. In other words, the left end of the second upper arm component 42 is connected to the right side frame 30 so as to be rotatable about an axis extending in the front-rear direction.

[0058] The right end of the first upper arm component 41 is connected to the left side portion of the upper connecting member 43 via the upper third support shaft 43a. The upper third support shaft 43a extends in the front-rear direction and is supported by the upper connecting member 43 in a state in which it penetrates the right end of the first upper arm component 41 in the front-rear direction. The upper third support shaft 43a is rotatable about an axis relative to the right end of the first upper arm component 41, or is rotatable about an axis relative to the upper connecting member 43. In other words, the right end of the first upper arm component 41 is connected to the upper connecting member 43 so as to be rotatable about an axis extending in the front-rear direction.

[0059] The left end of the second upper arm component 42 is connected to a right portion of the upper connecting member 43 via a fourth upper support shaft 43b. The fourth upper support shaft 43b extends in the front-rear direction and is supported by the upper connecting member 43 in a state in which it penetrates the left end of the second upper arm component 42 in the front-rear direction. The fourth upper support shaft 43b is rotatable about an axis relative to the left end of the second upper arm component 42, or is rotatable about an axis relative to the upper connecting member 43. In other words, the left end of the second upper arm component 42 is connected to the upper connecting member 43 so as to be rotatable about an axis extending in the front-rear direction.

[0060] The left end of the first lower arm component 51 is connected to the lower protruding plate portion 24c of the arm connecting member 24 of the left side frame 20 via a lower first support shaft 51a. The lower first support shaft 51a extends in the front-rear direction and is supported in a state where it is inserted into the lower through-hole 24d. The lower first support shaft 51a is rotatable about an axis relative to the left end of the first lower arm component 51, or rotatable about an axis relative to the lower protruding plate portion 24c. In other words, the left end of the first lower arm component 51 is connected to the left side frame 20 so as to be rotatable about an axis extending in the front-rear direction.

[0061] The left and right ends of the first lower arm component 51 are the left and right ends when in the unfolded state, and the upper and lower ends, respectively, when in the folded state. Similarly, the left and right ends of the second lower arm component 52 are the left and right ends when in the unfolded state, and the lower and upper ends, respectively, when in the folded state.

[0062] The right end of the second lower arm component 52 is connected to the lower protruding plate portion 34c of the arm connecting member 34 of the right side frame 30 via a lower second support shaft 52a. The lower second support shaft 52a extends in the front-rear direction and is supported in a state where it is inserted into the lower through-hole 34d. The lower second support shaft 52a is rotatable about an axis relative to the right end of the second lower arm component 52, or is rotatable about an axis relative to the lower protruding plate portion 34c. In other words, the left end of the second lower arm component 52 is connected to the right side frame 30 so as to be rotatable about an axis extending in the front-rear direction.

[0063] The right end of the first lower arm component 51 is connected to the left portion of the lower connecting member 53 via a lower third support shaft 53a. The lower third support shaft 53a extends in the front-rear direction and is supported by the lower connecting member 53 in a state in which it penetrates the right end of the first lower arm component 51 in the front-rear direction. The lower third support shaft 53a is rotatable about an axis relative to the right end of the first lower arm component 51, or is rotatable about an axis relative to the lower connecting member 53. In other words, the right end of the first lower arm component 51 is connected to the lower connecting member 53 so as to be rotatable about an axis extending in the front-rear direction.

[0064] The left end of the second lower arm component 52 is connected to a right portion of the lower connecting member 53 via a lower fourth support shaft 53b. The lower fourth support shaft 53b extends in the front-rear direction and is supported by the lower connecting member 53 in a state in which it penetrates the left end of the second lower arm component 52 in the front-rear direction. The lower fourth support shaft 53b is rotatable about an axis relative to the left end of the second lower arm component 52, or is rotatable about an axis relative to the lower connecting member 53. In other words, the left end of the second lower arm component 52 is connected to the lower connecting member 53 so as to be rotatable about an axis extending in the front-rear direction.

[0065] The upper support arm 40 is formed as a single arm by connecting the first upper arm component 41, the second upper arm component 42, and the upper connecting member 43, and the lower support arm 50 is formed as a single arm by connecting the first lower arm component 51, the second lower arm component 52, and the lower connecting member 53. The left end of the upper support arm 40 and the left end of the lower support arm 50 are connected to the left side frame 20, and the right end of the upper support arm 40 and the right end of the lower support arm 50 are connected to the right side frame 30, so that a truss structure whose nodes are all made of sliding joints is formed as a structural framework below the seat 3 by the left side frame 20, the right side frame 30, and the upper support arm 40 and the lower support arm 50 in the unfolded state.

[0066] FIG. 16 shows the positional relationship between the first upper arm component 41 and the second upper arm component 42 and the first lower arm component 51 and the second lower arm component 52 when they are in a folded state. In this embodiment, the first upper arm component 41 and the second upper arm component 42 rotate upward to fold the upper support arm 40, so the folding direction of the upper support arm 40 is upward. When the upper support arm 40 is folded, it takes a shape that forms a convex upward. On the other hand, the first lower arm component 51 and the second lower arm component 52 rotate downward to fold the lower support arm 50, so the folding direction of the lower support arm 50 is the opposite direction to the folding direction of the upper support arm 40, i.e., downward, and when the lower support arm 50 is folded, it takes a shape that forms a convex downward. Also, as shown in FIG. 14, the upper support arm 40 is positioned in front of the lower support arm 50 .

[0067] As shown in FIG. 15 and FIG. 16, a plurality of first upper teeth 41b are formed around the axis of the upper third support shaft 43a at the right end of the first upper arm component 41. A plurality of second upper teeth 42b are formed around the axis of the upper fourth support shaft 43b at the left end of the second upper arm component 42. The first upper teeth 41b and the second upper teeth 42b are arranged to mesh with each other. A plurality of first lower teeth 51b are formed around the axis of the lower third support shaft 53a at the right end of the first lower arm component 51. A plurality of second lower teeth 52b are formed around the axis of the lower fourth support shaft 53b at the left end of the second lower arm component 52. The first lower teeth 51b and the second lower teeth 52b are arranged to mesh with each other.

[0068] (Structure that holds the wheelchair body in the folded state) In this embodiment, a holding mechanism is provided for holding the wheelchair main body 2 in a folded state. By providing the holding mechanism, the wheelchair main body 2 in a folded state can be easily carried without being unfolded unexpectedly. The holding mechanism may also include a mechanism for holding the wheelchair main body 2 in an unfolded state. This stabilizes the wheelchair main body 2 in an unfolded state.

[0069] The holding mechanism will be described in detail below. For example, as shown in FIG. 10, the holding mechanism includes a left pin (first pin) 44a and a right pin (second pin) 44b as a first engaged part provided on the upper support arm 40, an engaged plate (second engaged part) 54 provided on the lower support arm 50, and an engaging part 70. The engaged part in this embodiment includes a first engaged part including the left pin 44a and the right pin 44b, and a second engaged part constituted by the engaged plate 54, but is not limited thereto, and only one of them may be provided. In other words, a structure including an engaged part provided on at least one of the upper support arm 40 and the lower support arm 50 may be used.

[0070] 15 and 16, the left pin 44a protrudes rearward from a portion of the first upper arm component 41 that is to the right of the longitudinal center, specifically from the left side of the upper third support shaft 43a. The right pin 44b protrudes rearward from a portion of the second upper arm component 42 that is to the left of the longitudinal center, specifically from the right side of the upper fourth support shaft 43b. The left pin 44a and the right pin 44 are parallel to each other.

[0071] 17, the engaged plate 54 is disposed in front of the right end of the first lower arm component 51 and the left end of the second lower arm component 52, and is attached rotatably relative to the right end of the first lower arm component 51 and the left end of the second lower arm component 52. Specifically, the front end of the lower third support shaft 53a and the front end of the lower fourth support shaft 53b pass through the engaged plate 54, and the lower third support shaft 53a and the lower fourth support shaft 53b are rotatable about their axes relative to the engaged plate 54. As a result, the first lower arm component 51 and the second lower arm component 52 are connected by the engaged plate 54 so as to be rotatable relative to each other.

[0072] A left protruding portion 54a protruding to the left is formed at the upper left portion of the engaged plate 54. A right protruding portion 54b protruding to the right is formed at the upper right portion of the engaged plate 54.

[0073] The engaging portion 70 is a portion that prevents relative vertical displacement at the left-right center between the upper support arm 40 and the lower support arm 50 by engaging with the left pin 44a and the right pin 44b when the upper support arm 40 and the lower support arm 50 are folded. In addition, the engaging portion 70 prevents relative vertical displacement at the left-right center between the upper support arm 40 and the lower support arm 50 by engaging with the engaged plate 54 when the upper support arm 40 and the lower support arm 50 are unfolded.

[0074] In this embodiment, the engaging portion 70 is provided on the upper connecting member 43, and the engaging portion 70 and the upper connecting member 43 are integrated, so that the engaging portion 70 and the upper connecting member 43 can form a fixed portion A (shown only in FIG. 18). In this case, the engaging portion 70 of the fixed portion A engages with the pins 44a, 44b or the engaged plate 54, thereby preventing relative vertical displacement between the upper support arm 40 and the lower support arm 50 at the left-right central portion. It is not necessary for the engaging portion 70 and the upper connecting member 43 to form the fixed portion A.

[0075] As shown in Fig. 18, the engagement portion 70 includes a left engagement member (first engagement member) 71 and a right engagement member (second engagement member) 72. The left engagement member 71 is supported on a portion of the upper connecting member 43 that is to the left of the left-right center via a left rotating shaft 71a. The left rotating shaft 71a is located lower than the upper third support shaft 43a and closer to the left-right center, and extends in the front-rear direction. Thus, the left engagement member 71 is rotatable about the axis of the left rotating shaft 71a.

[0076] An upper concave portion 71b is formed in the left engaging member 71 above the left rotating shaft 71a so as to open to the left. A lower concave portion 71c is formed in the left engaging member 71 below the left rotating shaft 71a so as to open to the right.

[0077] The right engagement member 72 is supported via a right rotation shaft 72a on a portion of the upper connecting member 43 that is to the right of the left-right center. The right rotation shaft 72a is located lower than the upper fourth support shaft 43b and closer to the left-right center, and extends in the front-rear direction. Therefore, the right engagement member 72 is rotatable about the axis of the right rotation shaft 72a.

[0078] An upper concave portion 72b is formed in the right engagement member 72 above the right rotation shaft 72a so as to open to the right. A lower concave portion 72c is formed in the right engagement member 72 below the right rotation shaft 72a so as to open to the left.

[0079] When the upper support arm 40 and the lower support arm 50 are folded, the left pin 44a (shown by phantom lines in FIG. 18) enters the upper concave portion 71b of the left engagement member 71 from the left side, and the left pin 44a that has entered the upper concave portion 71b engages in a state of contacting the inner surface of the upper concave portion 71b. When the upper support arm 40 and the lower support arm 50 are folded, the right pin 44b (shown by phantom lines in FIG. 18) enters the upper concave portion 72b of the right engagement member 72 from the right side, and the right pin 44b that has entered the upper concave portion 72b engages in a state of contacting the inner surface of the upper concave portion 72b.

[0080] When the upper support arm 40 and the lower support arm 50 are unfolded, the left protruding portion 54a of the engaged plate 54 enters the lower concave portion 71c of the left engaging member 71 from the lower right, and the left protruding portion 54a that has entered the lower concave portion 71c engages in a state of contact with the inner surface of the lower concave portion 71c. When the upper support arm 40 and the lower support arm 50 are unfolded, the right protruding portion 54b of the engaged plate 54 enters the lower concave portion 72c of the right engaging member 72 from the lower left, and the right protruding portion 54b that has entered the lower concave portion 72c engages in a state of contact with the inner surface of the lower concave portion 72c. Note that, in FIG. 18, both the engaged state when the upper support arm 40 and the lower support arm 50 are unfolded and the engaged state when they are folded are shown by virtual lines, but in reality, when one engaged state is in one engaged state, the other engaged state cannot be taken.

[0081] FIG. 18 shows the left engaging member 71 in an engaged position where it engages with the left pin 44a and the left protruding portion 54a. When the left engaging member 71 rotates rightward about the axis of the left rotating shaft 71a, it is positioned in a non-engaged position where it is not engaged with the left pin 44a and the left protruding portion 54a. Similarly, FIG. 18 shows the right engaging member 72 in an engaged position where it engages with the right pin 44b and the right protruding portion 54b. When the right engaging member 72 rotates leftward about the axis of the right rotating shaft 72a, it is positioned in a non-engaged position where it is not engaged with the right pin 44b and the right protruding portion 54b. In other words, the left engaging member 71 and the right engaging member 72 are each supported by the upper connecting member 43 so as to be rotatable between the engaged position and the non-engaged position.

[0082] The engagement portion 70 includes a biasing member 73 that biases the left engagement member 71 and the right engagement member 72 toward the engagement position. The biasing member 73 is formed of a torsion spring and has an annular portion 73a in the center, from which a first arm 73b and a second arm 73c extend. A pin-shaped spring support portion 43d is provided in the left-right center of the upper connecting member 43 so as to protrude rearward above the left rotating shaft 71a and the right rotating shaft 72a. The biasing member 73 is held by the upper connecting member 43 by inserting the spring support portion 43d into the annular portion 73a of the biasing member 73.

[0083] The first arm 73b of the biasing member 73 is engaged with a portion above the left pivot shaft 71a of the left engagement member 71. The second arm 73c of the biasing member 73 is engaged with a portion above the right pivot shaft 72a of the right engagement member 72. The biasing member 73 generates a biasing force in a direction that widens the gap between the first arm 73b and the second arm 73c, thereby biasing the left engagement member 71 and the right engagement member 72 toward their respective engagement positions.

[0084] When engaging the left pin 44a and the right pin 44b with the left engagement member 71 and the right engagement member 72, the upper support arm 40 and the lower support arm 50 in the unfolded state are folded, so that the left pin 44a and the right pin 44b approach the upper concave portions 71b, 72b, respectively, and enter the upper concave portions 71b, 72b while sliding against the periphery of the upper concave portions 71b, 72b. At this time, since the folding force is greater than the biasing force of the biasing member 73, the left engagement member 71 and the right engagement member 72 rotate against the biasing force of the biasing member 73, and then, when the left pin 44a and the right pin 44b are completely inserted, they are engaged.

[0085] When engaging the left protrusion 54a and the right protrusion 54b with the left engagement member 71 and the right engagement member 72, the upper support arm 40 and the lower support arm 50 in the folded state are unfolded, so that the left protrusion 54a and the right protrusion 54b approach the lower recesses 71c and 72c, respectively, and enter the lower recesses 71c and 72c while sliding against the introduction surfaces 71d and 72d formed below the lower recesses 71c and 72c. At this time, since the unfolding force is greater than the biasing force of the biasing member 73, the left engagement member 71 and the right engagement member 72 rotate against the biasing force of the biasing member 73, and then, when the left protrusion 54a and the right protrusion 54b are completely inserted, they are engaged.

[0086] As shown in Figures 11, 13, etc., the wheelchair main body 2 is equipped with an operating unit 80 for switching the engaging part 70 from an engaged state with the engaged part to a non-engaged state. The operating unit 80 is composed of a lever-shaped member extending in the front-rear direction, and is provided so as to penetrate the upper connecting member 43 in the front-rear direction. An intermediate part of the operating unit 80 in the front-rear direction is rotatably attached to the upper connecting member 43 by a mounting shaft 80a (shown in Figure 11) extending in the left-right direction, and this allows the operating unit 80 to freely swing around the mounting shaft 80a.

[0087] A front portion of the operating unit 80 protrudes forward from the front surface of the upper connecting member 43. Meanwhile, a rear portion of the operating unit 80 protrudes rearward from the rear surface of the upper connecting member 43. As shown by imaginary lines in FIG. 18, the rear portion of the operating unit 80 is disposed above a portion to the right of the left pivot shaft 71a of the left engaging member 71 and above a portion to the left of the right pivot shaft 72a of the right engaging member 72. When the operating unit 80 is operated so as to pull up the front portion of the operating unit 80, the rear portion of the operating unit 80 moves downward and pushes the left engaging member 71 and the right engaging member 72 downward. When the left engaging member 71 and the right engaging member 72 are pushed downward by the rear portion of the operating unit 80, the left engaging member 71 and the right engaging member 72 rotate against the biasing force of the biasing member 73 until they are in the disengaged position. This makes it possible to disengage the left side pin 44a and the right side pin 44b from the left side engagement member 71 and the right side engagement member 72, and to disengage the left side protrusion 54a and the right side protrusion 54b from the left side engagement member 71 and the right side engagement member 72.

[0088] The upper connecting member 43 is provided with a handle 48. The handle 48 protrudes forward from the front surface of the upper connecting member 43 and is positioned above the front portion of the operating unit 80. The wheelchair body 2 can be carried by holding the handle 48. The vertical distance between the handle 48 and the front portion of the operating unit 80 is set so that, for example, an adult can place the palm of their hand on the top surface of the handle 48 and hook their fingers on the front portion of the operating unit 80 to pull it up. This makes it easy to operate the operating unit 80 by using the handle 48. The handle 48 may protrude rearward.

[0089] (Support arm and footrest connection structure) In this embodiment, the folding direction and unfolding direction of the upper support arm 40 are the same as the folding direction and unfolding direction of the footrest 60, respectively, so a connecting structure is provided that connects the upper support arm 40 and the footrest 60 with a high-strength and high-rigidity member. That is, the wheelchair 1 includes a rod 85 that connects the left-right center of the upper support arm 40 and the left-right center of the footrest 60. The rod 85 is made of a member with high strength and rigidity, such as metal or the above-mentioned CFRP.

[0090] As shown in FIG. 9, the lower end (one end) of the rod 85 is connected to the bracket 63 of the footrest 60 via the third connecting shaft 63c. Therefore, the lower end of the rod 85 is only allowed to rotate around the axis of the third connecting shaft 63c relative to the bracket 63. On the other hand, the upper end (the other end) of the rod 85 is connected so as not to move relative to the front surface of the upper connecting member 43 located in the center of the upper support arm 40 in the left-right direction. As shown in FIG. 18, when the upper connecting member 43 constitutes a part of the fixing part A, the rod 85 can be connected to the first upper arm component 41 and the second upper arm component 42 constituting the upper support arm 40 via the fixing part A.

[0091] When the wheelchair user sits on the seat 3 with the wheelchair main body 2 unfolded and the seat 3 attached (as shown in FIG. 1), the weight of the wheelchair user is applied to the left side frame 20 and the right side frame 30, which causes a force in the unfolding direction to act on the upper support arm 40 and the lower support arm 50. The force applied to the upper support arm 40 is transmitted to the left-right center of the footrest 60 via the rod 85. Since the upper support arm 40 also unfolds in the same direction as the unfolding direction of the footrest 60, the force in the unfolding direction of the upper support arm 40 can be made to act on the footrest 60 as a force in the unfolding direction. As a result, the footrest 60 is maintained in an unfolded state, making it possible to improve the rigidity of the vehicle body using the footrest 60.

[0092] Furthermore, the force applied to the upper support arm 40 by the wheelchair user sitting on it is transmitted to the bracket 63 via the rod 85. As a result, the bracket 63 is sandwiched from the left and right directions between the left and right footrest component members 61 and 62, reducing wobbling of the footrest 60 and, as a result, further improving the rigidity of the vehicle body.

[0093] (Deployment operation assistance mechanism) In this embodiment, an auxiliary mechanism for the unfolding operation is provided to facilitate the unfolding operation when the wheelchair main body 2 is unfolded. As shown in Figures 13 and 14, the wheelchair 1 includes a flexible wire (tensioning member) 86 connected to the upper support arm 40 and the lower support arm 50, a winding device 87 capable of winding up the wire 86, and a gripper 88. A predetermined tension input to the wire 86 is configured to urge the upper support arm 40 and the lower support arm 50 in the folded state in the unfolding direction.

[0094] The wire 86 is a member for applying a force in the deployment direction to the upper support arm 40 and the lower support arm 50 in the folded state, and may be made of metal or resin. Instead of the wire 86, a long, thin, bendable or curveable member such as a string, thread, chain, rope, wire, etc. may be used as the tension applying member.

[0095] 18, the tip of the wire 86 is fixed to the rear portion of the operation unit 80. That is, since the operation unit 80 is provided on the upper connecting member 43, the tip of the wire 86 is connected to the upper connecting member 43 via the rear portion of the operation unit 80. Therefore, the tension of the wire 86 acts directly on the rear portion of the operation unit 80.

[0096] 14 and other drawings, wire 86 fixed to the rear portion of operation unit 80 extends downward, and is connected at its bottom end to lower connecting member 53 of lower support arm 50. Specifically, pulley 53d that rotates about an axis extending in the left-right direction is provided on the rear surface of lower connecting member 53, and wire 86 is connected to lower connecting member 53 with a middle portion of wire 86 wound around pulley 53d. Note that, without providing pulley 53d, a guide member may be provided on the rear surface of lower connecting member 53 to allow the middle portion of wire 86 to slide and prevent the middle portion of wire 86 from shifting in the left-right direction.

[0097] The upper connecting member 43 is provided with a base 89 on which the reeling device 87 can be placed. The base 89 protrudes rearward from the rear surface of the upper connecting member 43 and is formed so as to be positioned lower as it goes further rearward, with the rear portion of the base 89 having a shape that is recessed downward. By placing the reeling device 87 in the recessed portion of the base 89, the reeling device 87 is held so as not to move relative to the wheelchair main body 2 in the left-right and front-rear directions. In the folded state, the reeling device 87 placed on the base 89 is spaced upward from the pulley 53d.

[0098] The wire 86 wound around the pulley 53d extends upward and is then connected to a winding mechanism (not shown) provided inside the winding device 87. The winding device 87 is configured to be able to constantly apply a force in the winding direction to the wire 86, and a conventionally known winding mechanism can be used for the winding mechanism. The winding force of the wire 86 by the winding device 87 (in other words, the force required to unwind the wire 86) can be set arbitrarily by the winding mechanism, and in this embodiment, the wire 86 is unwound when pulled downward by a load smaller than the weight of the wheelchair body 2 (weight excluding the winding device 87). Although not shown, the winding device may be of an electric type. In the case of an electric type, for example, when a switch is operated, the wire 86 can be wound by a motor or the like, so there is no need to lift the winding device.

[0099] The grip part 88 provided on the upper part of the reeling device 87 is a part that a wheelchair user or the like grips when unfolding the wheelchair main body 2. Providing the grip part 88 on the upper part of the reeling device 87 makes it easy to grip the grip part 88 from above. As a result, the grip part 88 is attached via the reeling device 87 to the side of the wire 86 opposite to the side connected to the upper support arm 40 and the lower support arm 50.

[0100] When unfolding the folded wheelchair main body 2, for example, when a wheelchair user grasps the gripping portion 88 and lifts the winding device 87, the wire 86 is pulled upward. At this time, the wire 86 pulls the rear portion of the operating unit 80 downward, whereby the operating unit 80 is operated by the wire 86 to rotate the left engaging member 71 and the right engaging member 72 until they are in the disengaged position. In addition, since the wire 86 is connected to the left-right center portions of the upper support arm 40 and the lower support arm 50, when the tension of the wire 86 reaches a predetermined tension, the upper support arm 40 is biased in the unfolding direction and the lower support arm 50 is also biased in the unfolding direction, so that the upper support arm 40 and the lower support arm 50 are unfolded.

[0101] The winding device 87 is configured to be able to reel out the wire 86 until it is positioned a predetermined distance above a placement position (shown by a solid line in FIG. 14) on the base 89 and is disposed at a removal position (shown by a virtual line in FIG. 14) away from the base 89. Because the wire 86 is flexible, the direction of movement of the gripping part 88 held by the wheelchair user is unlikely to be restricted by the upper support arm 40 or the lower support arm 50, and the gripping part 88 can be moved relatively freely. This makes it possible to input a predetermined tension while pulling the gripping part 88 towards the user, or to move the gripping part 88 to a location where it is easy to input tension, making it easier to unfold the wheelchair main body 2.

[0102] The amount of wire 86 that can be let out of the winding device 87 is regulated so that it does not move upward more than a predetermined distance from the placement position on the base 89. In other words, if the vertical distance between the placement position and the removal position is long, the winding device 87 must be lifted up to a high place when unfolding, which may make the unfolding operation difficult, especially when the user is sitting down. In response to this, the amount of wire 86 that can be let out is determined in advance so that the winding device 87 does not have to be lifted up to a high place when unfolding, making the unfolding operation even easier.

[0103] As the lower support arm 50 unfolds, the left-right central portion of the lower support arm 50 moves upward, shortening the distance between the pulley 53d and the winding device 87 placed on the base portion 89. This results in excess of the wire 86, but since the excess portion of the wire 86 is wound up by the winding device 87, the wire 86 is less likely to become slack and is less likely to become entangled with other members, etc.

[0104] (Seat removal and attachment structure) 4, the seat 3 includes a seat cushion portion 91 on which a wheelchair user sits, a back cushion portion 92, and a seat frame 90. The seat frame 90 is provided under the seat 3, and is configured to be detachable from the left side frame 20 and the right side frame 30.

[0105] 19 and 20, the seat frame 90 includes a left frame portion 93 extending in the front-rear direction on the left side under the seat 3, a right frame portion 94 extending in the front-rear direction on the right side under the seat 3, and a connecting frame portion 95 (shown in FIG. 20) extending from the left frame portion 93 to the right frame portion 94 and connecting the left frame portion 93 and the right frame portion 94. The left frame portion 93 is accommodated in the left seat frame accommodating portion 21b and is supported by the seat support plate portion 23, and is detachable from the upper frame portion 21 of the left side frame 20. The right frame portion 94 is accommodated in the right seat frame accommodating portion 31b and is supported by the seat support plate portion 33, and is detachable from the upper frame portion 31 of the right side frame 30.

[0106] Since the left frame portion 93 and the right frame portion 94 have a symmetrical structure, the left frame portion 93 will be described in detail below. As shown in FIG. 21, the left frame portion 93 includes a clamping portion 100 that clamps the seat support plate portion 23 from the left and right directions while being supported by the seat support plate portion 23. The clamping portion 100 includes a frame abutment portion 101 and an abutment member 102. The frame abutment portion 101 and the abutment member 102 are shown as being hollow in the drawings, but may be solid. The frame abutment portion 101 is formed of a part of the left frame portion 93 in the front-rear direction, and is disposed so as to abut against the seat support plate portion 23 from the left side. The abutment member 102 is a member that abuts against the seat support plate portion 23 from the right side, and is disposed on the inner side of the seat frame 90 in the vehicle width direction. A lower portion of the abutting member 102 is disposed within a recess 23a (shown in FIG. 7) of the sheet support plate portion 23, and has a fitting portion 102a that fits into the recess 23a.

[0107] The abutment member 102 is supported so as to be movable in the left-right direction relative to the frame abutment portion 101. That is, as shown in FIG. 22, the frame abutment portion 101 has a plurality of guide pins 103 extending in the left-right direction. The guide pins 103 are arranged at intervals in the front-rear direction. The left end (base end) of the guide pin 103 is fixed to the frame abutment portion 101. The guide pin 103 extends so as to penetrate the abutment member 102 in the left-right direction, and the right end (tip end) of the guide pin 103 protrudes from the right side surface of the abutment member 102. The abutment member 102 is slidable in the left-right direction relative to the guide pin 103, so that the abutment member 102 is guided by the guide pin 103 and is movable only in the left-right direction.

[0108] A fixed shaft 104 is provided between the front guide pin 103 and the rear guide pin 103 of the abutting member 102. This fixed shaft 104 extends in the left-right direction substantially parallel to the guide pin 103, and the right end of the fixed shaft 104 is fixed to the abutting member 102. The fixed shaft 104 protrudes from the left side surface of the abutting member 102 toward the inside of the frame abutting portion 101. The left portion of the fixed shaft 104 is accommodated in an accommodating portion 105 provided inside the frame abutting portion 101.

[0109] A first coil spring 106 serving as a first biasing member is accommodated inside the accommodation portion 105. The left side portion of the fixed shaft 104 is accommodated inside the first coil spring 106, and the axis of the fixed shaft 104 and the central axis of the first coil spring 106 are aligned. One end of the first coil spring 106 is held inside the accommodation portion 105, and the other end of the first coil spring 106 is engaged with the left side portion of the fixed shaft 104. In this state, the first coil spring 106 constantly exerts a force on the fixed shaft 104 to bias the fixed shaft 104 to the left. Since the fixed shaft 104 is fixed to the abutting member 102, the biasing force of the first coil spring 106 acts as a force to bias the abutting member 102 in a direction to abut against the sheet support plate portion 23.

[0110] The clamping unit 100 has a locking unit 110 that locks the contact member 102 in a state where the contact member 102 is in contact with the sheet support plate unit 23. The locking unit 110 has a locking pin 111 and a second coil spring 112 as a second biasing member, and the locking pin 111 and the second coil spring 112 are disposed on the rear side of the contact member 102. A lock pin storage box 113 is provided on the left frame portion 93 so as to be adjacent to the rear side of the abutment member 102. A lock pin 111 is arranged inside the lock pin storage box 113 in a position extending in the front-rear direction. The lock pin 111 is supported so as to be movable in the front-rear direction relative to the lock pin storage box 113, and can be switched between an advanced state in which a front end portion (tip portion) of the lock pin 111 protrudes from the front surface of the lock pin storage box 113 and a retracted state in which the lock pin does not protrude from the front surface of the lock pin storage box 113.

[0111] A second coil spring 112 is also accommodated in the lock pin housing box 113. One end of the second coil spring 112 is held inside the lock pin housing box 113, and the other end of the second coil spring 112 is engaged with the lock pin 111. In this state, the second coil spring 112 is a member for biasing the lock pin 111 in the advancing direction.

[0112] A hole 102b into which the tip of the lock pin 111 is inserted is formed in the rear wall of the abutment member 102. The radial center of the hole 102b is positioned so as to coincide with the axis of the lock pin 111 when the abutment member 102 is in abutment with the sheet support plate 23. The biasing direction of the lock pin 111 by the second coil spring 112 is the forward direction, which coincides with the direction in which the tip of the lock pin 111 is inserted into the hole 102b. By inserting the tip of the lock pin 111 into the hole 102b, the abutment member 102 is prevented from moving in the left-right direction and is locked in abutment with the sheet support plate 23.

[0113] The inner surface of the hole 102b is provided with a guide surface 102c that guides the lock pin 111 into the hole 102b. The guide surface 102c is provided on the rear part of the inner surface of the hole 102b, that is, on the front side of the insertion direction of the lock pin 111 based on the insertion direction, and is configured as a tapered surface whose inner diameter increases toward the front side of the insertion direction. The guide surface 102c may be provided as necessary. In addition, for example, although not shown, the diameter of the lock pin 111 may be reduced toward the tip, which can achieve the same effect as when the guide surface 102c is provided, that is, the effect that the lock pin 111 can be reliably inserted into the hole 102b to lock the abutting member 102.

[0114] 4, 19, 20, etc., the seat 3 has a seat back frame 96 that supports a back cushion portion 92. The back cushion portion 92 and the seat back frame 96 form a seat back portion B.

[0115] A cross member 97 extending in the left-right direction is provided at the vertical middle portion of the seat back frame 96. The lower end of the seat back frame 96 is supported by the rear end of the seat frame 90 via a tilting portion 98. The tilting portion 98 is a portion that allows the seat back frame 96 to tilt forward. On both the left and right sides of the lower portion of the tilting portion 98, pressing portions 99 are provided that press the rear end of the upper frame portion 21 of the left side frame 20 and the rear end of the upper frame portion 31 of the right side frame 30 from the rear. When the seat 3 is removed from the left side frame 20 and the right side frame 30, the seat back frame 96 is tilted forward to separate the pressing portion 99 from the rear end of the upper frame portions 21, 31. When the seat 3 is attached, the seat back frame 96, which is tilted forward, is returned to the rear, so that the pressing portion 99 presses the rear end of the upper frame portions 21, 31, thereby suppressing rattling of the seat 3.

[0116] As shown in FIG. 23, the cross member 97 of the seat back portion B is provided with an unlocking operation part 120. The unlocking operation part 120 has a release mechanism 121 provided inside the center of the cross member 97 in the left-right direction, and a release lever 122 provided to protrude downward from the cross member 97. The release mechanism 121 has a left swinging member 123 and a right swinging member 124 supported by shafts 123a and 124a so as to be swingable in the vertical direction relative to the cross member 97. The release lever 122 is disposed in a position extending in the vertical direction, and the upper end of the release lever 122 is rotatably connected to the left swinging member 123 and the right swinging member 124 via the swinging shaft 122a. Therefore, when the release lever 122 is moved upward, the left swinging member 123 and the right swinging member 124 swing upward around the shafts 123a and 124a, respectively.

[0117] A base end of a left operation wire 130 for operating the lock pin 111 is connected to a portion of the left rocking member 123 below the support shaft 123a. The left operation wire 130 passes through the cross member 97 and the seat back frame 96, and reaches the left frame portion 93 as shown in FIG. 22. The tip end of the left operation wire 130 is connected to the base end of the lock pin 111 via a connecting member 130a. In other words, since the lock portion 110 is connected to the unlocking operation portion 120 via the left operation wire 130, the biasing force of the second coil spring 112 acts on the left operation wire 130.

[0118] In addition, since the lock pin 111 is disposed on the rear side of the abutting member 102, it is possible to bring the lock pin 111 close to the unlocking operation part 120. This makes it possible to shorten the length of the left side operation wire 130 and makes it easier to handle the left side operation wire 130, improving operability when unlocking.

[0119] When the left swing member 123 is swung upward by the release lever 122, the left operation wire 130 is pulled, and the pulling force of the left operation wire 130 acts on the lock pin 111 in the direction of pulling it out of the hole 102b (unlocking direction).

[0120] 23, a right operation wire 131 is connected to the right swing member 124 in the same manner as the left side. This right operation wire 131 is a member for unlocking the right lock pin (not shown). In this embodiment, the left frame portion 93 and the right frame portion 94 have a symmetrical structure, but one of them does not need to be provided with a clamping portion.

[0121] In the attachment / detachment structure of the seat 3 according to this embodiment, when the seat frame 90 is attached to the left side frame 20 and the right side frame 30, the left side frame 20 can be clamped in the left-right direction by the clamping portion 100 of the seat frame 90, making it easy to attach the seat 3. Furthermore, by clamping the left side frame 20 in the left-right direction by the clamping portion 100 of the seat frame 90, play is less likely to occur between the seat frame 90 and the left side frame 20, and rattling of the seat 3 after attachment is suppressed. The right side frame 30 can be clamped by the right clamping portion.

[0122] In addition, the abutting member 102 of the clamping part 100 is locked in abutment against the left side frame 20 by the biasing force of the first coil spring 106, so that the seat 3 is firmly fixed to the left side frame 20. On the other hand, when removing the seat 3, the unlocking operation part 120 is operated, and the operating force is transmitted to the lock pin 111 via the left operation wire 130 to release the lock. At this time, the unlocking operation part 120 is provided on the seat back part B, which is located higher than the seat cushion part 91, so that operability is good.

[0123] (Action and effect) As described above, according to this embodiment, by folding the upper support arm 40 and the lower support arm 50 in the vertical direction, the left side frame 20 and the right side frame 30 approach each other and the wheelchair main body 2 is in a folded state. When the left engaging member 71 and the right engaging member 72 of the engaging portion 70 are engaged with the left pin 44a and the right pin 44b with the wheelchair main body 2 in the folded state, the upper support arm 40 and the lower support arm 50 are prevented from being displaced relative to each other in the vertical direction at their left-right central portions, so that both support arms 40, 50 do not unfold and are maintained in the folded state.

[0124] Furthermore, when unfolding the folded wheelchair main body 2, the tension of the wire 86 can be used to release the engagement portion 70 and unfold the upper support arm 40 and the lower support arm 50 simply by lifting the winding device 87, making the unfolding operation easy. During this unfolding, the footrest 60 can be maintained in an unfolded state when getting on by connecting the upper support arm 40 and the foldable footrest 60, which connects the front end of the left side frame with the front end of the right side frame, with the rod 85. This allows the use of the footrest 60 to improve the rigidity of the vehicle body.

[0125] The above-described embodiment is merely illustrative in all respects and should not be construed as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention. [Industrial Applicability]

[0126] As described above, the wheelchair according to the present disclosure can be used, for example, when being carried in a car or the like. [Explanation of symbols]

[0127] 1. Wheelchair 10, 11 Left drive wheel, right drive wheel 20 Left side frame 30 Right side frame 40 Upper support arm 44a, 44b Left pin (first pin), right pin (second pin) 50 Lower Support Arm 54 Engaged plate (second engaged portion) 60 Footrest 70 Engagement part 80 Control section 85 Rod 86 Wire (tensioning member) 87 Winding device 88 Gripping part 89 Pedestal 90 Seat frame 100 Clamping part 101 Frame abutment 102 Contact member 106 First coil spring (first biasing member) 111 Lock pin

Claims

1. A folding wheelchair equipped with a seat on which a wheelchair user can sit, A left side frame that supports the drive wheel on the left side of the vehicle body; A right side frame that supports the drive wheels on the right side of the vehicle body; a foldable support arm connecting the left side frame and the right side frame, The seat includes a seat frame configured to be detachable from the left side frame and the right side frame, The wheelchair, wherein the seat frame is provided with a clamping portion that clamps at least one of the left side frame and the right side frame from the left and right directions.

2. 2. The wheelchair according to claim 1, the clamping portion is formed of a part of the seat frame, and has a frame abutment portion that abuts against one of the side frames from one side in the left-right direction, an abutment member that abuts against the one of the side frames from the other side in the left-right direction, a first biasing member that biases the abutment member in a direction in which the abutment member abuts against the one of the side frames, and a locking portion that locks the abutment member in a state in which the abutment member abuts against the one of the side frames, The locking portion is connected to an unlocking operation portion provided on a seat back portion of the seat via an operation wire.

3. 3. The wheelchair according to claim 2, the locking portion includes a locking pin that is inserted into a hole portion of the abutment member in a state where the locking portion is supported by the seat frame, and a second biasing member that biases the locking pin in a direction of inserting the locking pin into the hole portion, A wheelchair, wherein an inner surface of the hole portion is provided with a guide surface that guides the lock pin into the hole portion.

4. 4. The wheelchair according to claim 3, The operating wire is connected to the lock pin, The lock pin and the second biasing member are disposed on a vehicle body rear side of the abutment member.

5. 3. The wheelchair according to claim 2, A recess is provided on a side surface of the one side frame at a middle portion in the front-rear direction, A wheelchair, wherein the abutment member has a fitting portion that fits into the recess.

6. 3. The wheelchair according to claim 2, The abutment member is disposed on an inner side of the seat frame in a vehicle width direction.

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