Electric wheelchairs and electric wheelchair wheels

Abstract

This simplifies the process of attaching the wheels to the frame. [Solution] The operating rod 32 is axially relative to the axle 31 between a wheel lock position that positions the wheel lock member 33 in an engaged position and a wheel unlock position that allows the wheel lock member 33 to move to an unlocked position. The operating rod 32 is pushed from the wheel unlock position toward the wheel lock position by the elastic force of the first elastic member 38, and is movable from the wheel lock position toward the wheel unlock position by being pushed by the user. The stopper member 34 engages with the operating rod 32 when the operating rod 32 is in the wheel unlock position and maintains the operating rod 32 in the wheel unlock position against the elastic force of the first elastic member 38.

Description

Technical Field

[0001] The present disclosure relates to an electric wheelchair and a wheel of an electric wheelchair.

Background Art

[0002] The electric wheelchair disclosed in Patent Document 1 below has electric motors on the left and right wheels. The wheels can be removed from the frame of the electric wheelchair. The user can load the electric wheelchair into a vehicle or store it at home with the wheels removed.

[0003] In the electric wheelchair of Patent Document 1, the wheel has a rod 48 inserted inside a cylindrical axle. A locking member 49 is attached to the tip of the rod 48. Balls 52 are arranged on the outer peripheral surface of the locking member 49, and the locking member 49 pushes the balls 52 out to the outside of the outer peripheral surface of the axle ១១. These balls 52 engage with a sleeve 54 provided on the frame, and the wheel is locked to the frame. That is, separation of the wheel from the frame is restricted. When the user pushes the rod 48 against the elastic force of the spring 51, the position of the locking member 49 is displaced from the position of the balls 52. As a result, sinking of the balls 52 is allowed, and the engagement between the balls 52 and the sleeve 54 is released. Thereby, the user can remove the wheel from the frame.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In Patent Document 1, in order to reattach the wheel that has been removed to the frame, the user must continue to push the rod 48 against the elastic force of the spring 51. However, the wheel is heavy because it has a built-in electric motor. When attaching the wheel to the frame, the process of holding the heavy wheel while continuously pushing the rod 48 and fitting the axle 11 into the sleeve 54 is cumbersome. [Means for solving the problem]

[0006] (1) The wheel of the electric wheelchair proposed in this disclosure comprises a cylindrical axle for fitting inside a cylindrical support portion provided on the vehicle body, an operating rod inserted inside the cylindrical axle, a first elastic member, a wheel lock member movable radially of the cylindrical axle between an engagement position in which it engages with the cylindrical support portion and a release position in which it does not engage with the cylindrical support portion, and a stopper member. The operating rod is axially relative to the cylindrical axle between a wheel lock position in which the wheel lock member is positioned in the engagement position and a wheel lock release position that allows the wheel lock member to move to the release position. The operating rod is pushed from the wheel lock release position toward the wheel lock position by the elastic force of the first elastic member, and is movable from the wheel lock position toward the wheel lock release position by being pushed by a user. The stopper member engages with the operating rod when the operating rod is in the wheel lock release position and maintains the operating rod in the wheel lock release position against the elastic force of the first elastic member.

[0007] (2) In the wheel described in (1), the stopper member is positioned in a housing hole formed in the cylindrical axle and is movable in the radial direction of the cylindrical axle inside the housing hole. A stoppered portion is formed on the operating rod. The stopper member engages with the stoppered portion when the operating rod is in the wheel unlocked position to maintain the operating rod in the wheel unlocked position.

[0008] (3) In the wheel described in (2), the stopper member has a through hole that penetrates the stopper member in the axial direction, the operating rod extends in the axial direction through the through hole, and the stopper member has an engaging portion on the inside of the through hole that engages with the portion to be stopped.

[0009] (4) In the wheel described in any of (1) to (3), when the operating rod is in the wheel unlock position, the cylindrical axle is removed from the cylindrical support in the axial direction, and the operating rod automatically returns from the wheel unlock position to the wheel lock position by the elastic force of the first elastic member.

[0010] (5) In the wheel described in any of (2) to (4), the wheel lock release position includes a first position and a second position which is closer to the wheel lock position than the first position. The operating rod is pushed by the first elastic member from the first position toward the second position. When the operating rod is in the first position, the operating rod allows the wheel lock member to move toward the release position, and the stopper member engages with the stopped portion, maintaining the operating rod in the first position. When the operating rod is in the second position, the operating rod allows the wheel lock member to move toward the release position, and the stopper member is not engaged with the stopped portion.

[0011] In the wheel described in (6)(5), when the stopper member is located inside the cylindrical support portion together with the cylindrical axle, the operating rod is not maintained in the first position but moves to the second position due to the elastic force of the first elastic member.

[0012] In the wheel described in (7), (5), or (6), the stopper member is movable in the radial direction of the cylindrical axle between a stopper position in which the stopper member engages with the portion to be stopped and maintains the operating rod in the first position, and a stopper release position in which the engagement between the stopper member and the portion to be stopped is released. The stopper member is biased from the stopper release position to the stopper position by the elastic force of the second elastic member. When the stopper member is inside the cylindrical support portion together with the cylindrical axle, its movement from the stopper release position to the stopper position is restricted.

[0013] In the wheel described in (8)(7), the stopper member has an interference portion that protrudes from the outer circumferential surface of the cylindrical axle when the stopper member is in the stopper position. When the stopper member is inside the cylindrical support together with the cylindrical axle, the interference portion interferes with the inner circumferential surface of the cylindrical support, restricting the movement of the stopper member from the stopper release position to the stopper position.

[0014] (9) In the wheel described in any of (1) to (8), the maintenance of the operating rod in the wheel lock release position is automatically released during the process in which the cylindrical axle is inserted into the inside of the cylindrical support portion while the operating rod is in the wheel lock release position.

[0015] In the wheel described in any of (10)(2) to (8), the stopper member is movable in the radial direction of the cylindrical axle between a stopper position in which the stopper member engages with the stopped portion and maintains the operating rod in the hole-lock release position, and a stopper release position in which the engagement between the stopper member and the stopped portion is released. The stopper member has an interference portion that protrudes from the outer circumferential surface of the cylindrical axle when the stopper member is in the stopper position. The interference portion is pushed by the inner circumferential surface of the cylindrical support portion, moving the stopper member from the stopper position to the stopper release position.

[0016] (11) In the wheel according to any one of (1) to (10), when the operating rod is in the wheel locking position, the operating rod pushes out the wheel locking member to the outside in the radial direction of the tubular axle so that the wheel locking member and the tubular support portion engage with each other. When the operating rod is in the wheel unlocking position, the operating rod allows the wheel locking member to sink toward the center in the radial direction of the tubular axle.

[0017] (12) In the wheel according to (11), the operating rod has a large-diameter portion and a small-diameter portion that are separated in the axial direction. When the operating rod is in the wheel locking position, the large-diameter portion pushes out the wheel locking member to the outside in the radial direction of the tubular axle and restricts the movement of the wheel locking member in the radial direction. When the operating rod is in the wheel unlocking position, the small-diameter portion allows the wheel locking member to sink toward the center in the radial direction of the tubular axle.

[0018] (13) The electric wheelchair proposed in the present disclosure includes the wheel according to any one of (1) to (12).

Effect of the Invention

[0019] According to the electric wheelchair and the wheel proposed in the present disclosure, the work of attaching the wheel to the vehicle body can be facilitated.

Brief Description of the Drawings

[0020] [Figure 1] It is a side view of an electric wheelchair. [Figure 2] It is a cross-sectional view of the wheel taken along the line II-II shown in FIG. 1. [Figure 3A] It is an exploded perspective view showing the main part of the wheel. [Figure 3B] It is an enlarged view of the operating rod shown in FIG. 3A. [Figure 4A] It is a perspective view of the stopper member. [Figure 4B] It is a side view of the stopper member. [Figure 5] It is a cross-sectional view for explaining the movements of the operation rod, the wheel lock member, and the stopper member. In (a) of the figure, the operation rod is disposed at the wheel lock position. In (b) of the figure, the operation rod is disposed at the wheel lock release position. [Figure 6] It is a cross-sectional view for explaining the movements of the operation rod, the wheel lock member, and the stopper member. In (a) of the figure, the operation rod is disposed at a first position which is a part of the wheel lock release position. In (b) of the figure, the operation rod is disposed at a second position which is another part of the wheel lock release position. [Figure 7] It is a view for explaining the operation performed by an operator when removing the axle from the cylindrical support portion fixed to the frame, and the movements of each member. [Figure 8] It is an enlarged view of FIG. 7. [Figure 9] It is a view for explaining the operation performed by an operator when attaching the axle to the cylindrical support portion fixed to the frame, and the movements of each member.

Embodiments for Carrying out the Invention

[0021] Hereinafter, the electric wheelchair and the wheel of the electric wheelchair proposed in the present disclosure will be described. FIG. 1 is a side view of an electric wheelchair 100 which is an example of the electric wheelchair proposed in the present disclosure.

[0022] In the following description, the Z1 and Z2 directions shown in FIG. 1 are respectively referred to as upward and downward. Also, the Y1 and Y2 directions shown in FIG. 1 are respectively referred to as forward and backward. The X1 and X2 directions shown in FIG. 2 are respectively referred to as rightward and leftward. The X1-X2 direction shown in FIG. 2 is also the direction along the axis Ax of the axle 31 of the wheel 10. The direction along the axis Ax is referred to as the "axial direction".

[0023] As shown in Figure 1, the electric wheelchair 100 has wheels 10 positioned on the right and left sides of the vehicle body. Tires 11 are attached to the outer circumference of the wheels 10. The wheels 10 also have handrims 12 positioned along the tires 11 and a cover 13 that covers the electric motor 20, which will be described later. The electric wheelchair 100 has a battery 71 that stores the power supplied to the electric motor 20 and a battery holder 72 that holds the battery 71.

[0024] As shown in Figure 1, the electric wheelchair 100 has casters 66 positioned in front of the wheels 10, foot supports 61 for the user's feet, a seat 62 for the user to sit on, a back support 63 for supporting the user's back, and arm supports 64 for the user's arms. An operating unit 65 that receives input from the user is positioned in front of the arm supports 64. The user can input instructions regarding the direction of travel and speed of the wheelchair 100 through the operating unit 65. The operating unit 65 may have, for example, a joystick 65a. The operating unit 65 may also have a power switch and a switch for adjusting the maximum speed.

[0025] As shown in Figure 1, the electric wheelchair 100 has a frame 50. The frame 50 has rear frame sections 51 that are located on the right and left sides of the vehicle body and extend vertically. The rear frame sections 51 support the right and left sides of the back support 63. The frame 50 may also have a seat frame section 52 that supports the right and left sides of the seat 62, and a lower frame section 53 located below the seat frame section 52 that supports casters 66, etc.

[0026] The wheels 10 will be described below. As mentioned above, the electric wheelchair 100 has two wheels 10, one on the left side and one on the right side of the vehicle body. In this specification, the wheel 10 located on the right side will be described with reference to Figures 2 to 9. The structures of the left and right wheels 10 may be symmetrical.

[0027] [wheel] As shown in Figure 2, the wheel 10 includes an axle 31, a rotating shaft 41, an electric motor 20, and a reduction mechanism 40.

[0028] As shown in Figure 2, the body of the electric wheelchair 100 is provided with a support section 55 for supporting the wheels 10. The support section 55 is cylindrical. The axle 31 is inserted inside this support section 55. The axle 31 is inserted into the support section 55 from the outside in the left-right direction of the vehicle body. That is, the axle 31 of the right wheel 10 is inserted into the support section 55 from the right side of the vehicle body. Conversely, the axle 31 of the left wheel 10 is inserted into the support section 55 from the left side of the vehicle body.

[0029] The support portion 55 is fixed to the frame 50. The support portion 55 is fixed, for example, to the lower part of the rear frame portion 51. A screw hole that penetrates the rear frame portion 51 in the axial direction (X1-X2 direction) may be formed in the lower part of the rear frame portion 51. The support portion 55 may be inserted into this screw hole. In this case, threads may be formed on the outer surface of the support portion 55. Washers 56 may be placed at the ends of the support portion 55 (the outer ends in the left-right direction).

[0030] The support portion 55 is not limited to being fixed to the rear frame portion 51. For example, the support portion 55 may be fixed to the rear of the lower frame portion 53.

[0031] As shown in Figure 2, the electric motor 20 has a rotor 21 that is rotatable around the axis Ax of the axle 31 and a stator 22. The rotor 21 and stator 22 are, for example, facing each other in the axial direction. The rotor 21 has, for example, permanent magnets, and the stator 22 has coils.

[0032] As shown in Figure 2, a through hole is formed in the center of the rotor 21. The rotating shaft 41 is inserted into this through hole. The inner circumferential surface of the through hole engages with the outer circumferential surface of the rotating shaft 41, so that the rotor 21 and the rotating shaft 41 can rotate together. The wheel 10 has a hub 15 (see Figure 2) which is connected to a rim 14 (see Figure 1) via spokes 16. The rotation of the rotating shaft 41 is transmitted to the hub 15 via a reduction mechanism 40. The reduction mechanism 40 is, for example, a two-stage planetary gear mechanism.

[0033] As shown in Figure 2, the electric motor 20 has a motor housing 23. The rotor 21 and stator 22 described above are arranged inside the motor housing 23. The hub 15 has an outer circumference 15a that is located radially outward from the motor housing 23 and surrounds the motor housing 23, and a side portion 15b that is located outward in the left-right direction from the motor housing 23. An operation button 37 may be located in a through hole formed in the center of the side portion 15b. As will be described later, the operator can remove the wheel 10 from the vehicle body by pressing this operation button 37.

[0034] [Wheel attachment / detachment mechanism] The wheel 10 is detachable from the body of the electric wheelchair 100. More specifically, the axle 31 of the wheel 10 is detachable from the support part 55 which is fixed to the frame 50.

[0035] As shown in Figure 3A, the axle 31 is formed in a cylindrical shape. The wheel 10 has an operating rod 32 inserted inside the axle 31 and a wheel locking member 33. The wheel locking member 33 is a member for fixing the axle 31 to the support part 55, that is, for preventing the axle 31 from coming out of the support part 55. The aforementioned operating button 37 (see Figure 2) is attached to the base of the operating rod 32.

[0036] [Wheel locking component] The wheel lock member 33 is, for example, a ball. As shown in Figure 5(a), the wheel 10 has, for example, two wheel lock members 33 positioned on opposite sides of the axis Ax. The axle 31 has a housing hole 31a that penetrates the axle 31 in the radial direction. The wheel lock member 33 is positioned inside this housing hole 31a. The wheel lock member 33 is movable inside this housing hole 31a in the radial direction of the axle 31 (in the direction perpendicular to X1-X2 in Figure 5). Specifically, the wheel lock member 33 is movable between the engaged position shown in Figure 5(a) and the released position shown in Figure 5(b).

[0037] When the wheel lock member 33 is in the engaged position, it engages with the support portion 55. As shown in Figure 5(a), when the wheel lock member 33 is in the engaged position, a portion of the wheel lock member 33 protrudes radially outward from the outer circumferential surface 31g of the axle 31. As a result, the distance from the axis Ax to this portion of the wheel lock member 33 becomes greater than the outer diameter (radius) of the outer circumferential surface of the axle 31. This portion of the wheel lock member 33 then catches on the support portion 55. This prevents the axle 31 from coming out of the support portion 55.

[0038] The wheel lock member 33 hooks onto, for example, the inner end 55a of the support portion 55 (the end closer to the center in the left-right direction of the electric wheelchair 100). This prevents the axle 31 from coming out of the support portion 55. The position where the wheel lock member 33 hooks does not have to be the inner end 55a of the support portion 55. For example, a hole may be formed in the inner circumferential surface of the cylindrical support portion 55, and a part of the wheel lock member 33 may fit into this hole.

[0039] As shown in Figure 5(b), the wheel lock member 33 does not engage with the support portion 55 when it is in the released position. In other words, when the wheel lock member 33 is in the released position, the engagement between the wheel lock member 33 and the support portion 55 is released. The movement (sinking) of the wheel lock member 33 toward the axis Ax of the axle 31 is permitted by the small diameter portion 32b of the operating rod 32, which will be described later. As a result, the entire wheel lock member 33 fits inside the outer circumferential surface 31g of the axle 31. This allows the axle 31 to detach from the support portion 55.

[0040] Furthermore, the shape of the wheel lock member 33 is not limited to a ball. The shape of the wheel lock member 33 is not particularly limited as long as it can restrict the axle 31 from coming out of the support part 55. Also, there may be one wheel lock member 33 or more than two.

[0041] [Operating rod] The operating rod 32 is axially movable relative to the axle 31. The operating rod 32 is movable between a wheel lock position (Figure 5(a)) that positions the wheel lock member 33 in the engaged position and a wheel lock release position (Figure 5(b)) that allows the wheel lock member 33 to move to the release position. The operating rod 32 is biased outward in the left-right direction by a first elastic member 38 (see Figure 3A). The operating rod 32 moves from the wheel lock position (Figure 5(a)) to the wheel lock release position (Figure 5(b)) when an operator presses the operating button 37 (see Figure 2) from the outside in the left-right direction.

[0042] As shown in Figure 3B, the operating rod 32 has a large-diameter section 32a at its tip. The operating rod 32 also has a small-diameter section 32b that is smaller in diameter than the large-diameter section 32a. The small-diameter section 32b is located closer to the base of the operating rod 32 (operating button 37).

[0043] As shown in Figure 5(a), when the operating rod 32 is in the wheel lock position, the position of the large-diameter portion 32a coincides with the position of the housing hole 31a where the wheel lock member 33 is located. The large-diameter portion 32a then pushes the wheel lock member 33 outward in the radial direction of the axle 31, restricting the movement (sinking) of the wheel lock member 33 toward the axis Ax (the radial center of the axle 31).

[0044] On the other hand, as shown in Figure 5(b), when the operating rod 32 is in the wheel lock release position, the position of the small-diameter portion 32b coincides with the position of the housing hole 31a where the wheel lock member 33 is located. The small-diameter portion 32b then allows the wheel lock member 33 to move (sink) toward the axis Ax (the radial center of the axle 31). This allows the wheel lock member 33 to be positioned in the release position.

[0045] As shown in Figure 3B, both the large-diameter portion 32a and the small-diameter portion 32b are cylindrical. However, the shapes of the large-diameter portion 32a and the small-diameter portion 32b are not limited to these. The large-diameter portion 32a does not have to be cylindrical as long as it is a shape that restricts the movement (sinking) of the wheel lock member 33 toward the axis Ax. For example, the large-diameter portion 32a may be a convex portion that protrudes toward the inside of the housing hole 31a. Also, the small-diameter portion 32b does not have to be cylindrical as long as it is a shape that allows the movement (sinking) of the wheel lock member 33 toward the axis Ax. For example, the small-diameter portion 32b may be a recess formed on the outer circumferential surface of the operating rod 32.

[0046] [First elastic member] As described above, the wheel 10 has a first elastic member 38 (see Figure 3A). The first elastic member 38 biases the operating rod 32 outward in the left-right direction. In other words, the first elastic member 38 biases the operating rod 32 in the direction from the wheel unlocked position to the wheel locked position. In Figure 5, the first elastic member 38 pushes the operating rod 32 to the right.

[0047] The first elastic member 38 is, for example, a coil spring. As shown in Figure 5(a), the operating rod 32 is inserted inside the first elastic member 38. The first elastic member 38, together with the operating rod 32, is inserted inside the axle 31. One end of the first elastic member 38 is supported by a receiving surface 31e formed on the inner circumferential surface of the axle 31. The other end of the first elastic member 38 is supported by a stopper ring 35 attached to the operating rod 32. The first elastic member 38 pushes the stopper ring 35 outward in the left-right direction.

[0048] The movement of the stopper ring 35 to the right, i.e., outward movement of the stopper ring 35 in the left-right direction, is restricted by other members of the wheel 10. The movement of the stopper ring 35 to the right may be restricted, for example, by a rotating shaft 41 (see Figure 2) which is located coaxially with the axle 31.

[0049] [Stopper component] As shown in Figure 3A, the wheel 10 has a stopper member 34. The stopper member 34 engages with the operating rod 32 when the operating rod 32 is in the wheel unlock position. The stopper member 34 then maintains the position of the operating rod 32 in the wheel unlock position against the elastic force of the first elastic member 38.

[0050] As shown in Figure 4A, the stopper member 34 has a through hole 34a that penetrates the stopper member 34 in the axial direction. The operating rod 32 is inserted inside this through hole 34a. An engaging portion 34b (see Figure 4A) is formed inside the through hole 34a. The engaging portion 34b is, for example, a convex portion that protrudes inward from the through hole 34a. The operating rod 32 has a stopped portion 32c (see Figure 3B). The stopped portion 32c is, for example, a portion that is thinner (smaller in diameter) than the rest of the operating rod 32. As shown in Figure 6(a), the engaging portion 34b fits into this stopped portion 32c and maintains the operating rod 32 in the wheel lock release position. In other words, the engaging portion 34b restricts the movement of the operating rod 32 from the wheel lock release position to the wheel lock position.

[0051] As shown in Figure 3B, the operating rod 32 has a recess, which is the stopper portion 32c, formed around the entire circumference of the outer surface of the operating rod 32. Alternatively, the stopper portion 32c may be a recess or hole formed only on a part of the outer surface of the operating rod 32.

[0052] Note that the structure of the stopper member 34 and the stopped portion 32c is not limited to the example described here. For example, contrary to the example shown in Figure 4A, a through hole may be formed in the operating rod 32, and the stopper member 34 may be fitted into this through hole. The stopped portion 32c may then be formed in this through hole.

[0053] [Operation procedures by the worker and the movement of the operating rod, etc.] Referring to Figures 7 and 8, the operations performed by the worker when removing the wheel 10 from the vehicle body will be described. Figures 8(a), (b), and (c) are enlarged views of Figures 7(a), (b), and (c), respectively.

[0054] In the initial state (with the axle 31 fitted into the support portion 55), as shown in Figure 5(a), the operating rod 32 is in the wheel lock position and the wheel lock member 33 is in the engagement position. As shown in Figure 7(a), the operator pushes the operating rod 32 (more specifically, the operating button 37) towards the center in the left-right direction, against the elastic force of the elastic member 38. As a result, as shown in Figure 8(a), the operating rod 32 is placed in the wheel lock release position, and the movement of the wheel lock member 33 toward the release position (sinking toward the axis Ax) is permitted.

[0055] Subsequently, as shown in Figure 7(b), the operator stops pushing the operating rod 32. Then, as shown in Figure 7(c), the operator pulls the axle 31 out of the support 55. At this time, the operator separates the axle 31, along with the electric motor 20, hub 15, and rotating shaft 41 from the frame 50.

[0056] As shown in Figures 8(a) and 8(b), when the axle 31 is inside the support portion 55, the stopper function of the stopper member 34 described above does not work even when the operating rod 32 is positioned in the wheel lock release position. That is, the engaging portion 34b of the stopper member 34 does not engage with the stopped portion 32c of the operating rod 32. Therefore, as shown in Figures 7(c) and 8(c), when the axle 31 is completely pulled out from the support portion 55, the operating rod 32 automatically returns to the wheel lock position due to the elastic force of the first elastic member 38. The structure that realizes this operation of the wheel 10 will be described in detail later.

[0057] Referring to Figure 9, the operations performed by the worker when attaching the wheel 10 to the vehicle body will be explained.

[0058] In the initial state (where the entire axle 31 is outside the support portion 55), the operating rod 32 is positioned in the wheel lock position. Therefore, as shown in Figure 8(c), the wheel lock member 33 is in the engaged position. The operator pushes the operating rod 32 (more specifically, the operating button 37) against the elastic force of the first elastic member 38 to position the operating rod 32 in the wheel lock release position (Figure 9(a)). This allows the wheel lock member 33 to move to the release position. At this time, the stopper member 34 described above also comes into action. Therefore, even if the operator stops pushing the operating rod 32, the position of the operating rod 32 is maintained in the wheel lock release position.

[0059] Next, as shown in Figure 9(b), the operator inserts the axle 31 into the support portion 55. As will be described later, the stopper function of the stopper member 34 is automatically released during the process of inserting the axle 31 into the support portion 55. Therefore, as shown in Figure 9(c), when the axle 31 is fully inserted into the support portion 55, the operating rod 32 moves from the wheel lock release position to the wheel lock position due to the elastic force of the first elastic member 38. As a result, the wheel lock member 33 is pushed radially outward by the large diameter portion 32a of the operating rod 32, as shown in Figure 5(a), and engages with the inner end portion 55a of the support portion 55. In other words, the wheel 10 is fixed to the support portion 55.

[0060] In this way, when the worker attaches the wheel 10 to the frame 50 (support portion 55), the stopper member 34 temporarily maintains the position of the operating rod 32 in the wheel lock release position. This allows the worker to stop pushing the operating rod 32. Therefore, the worker can hold the wheel 10 with both hands and fit the axle 31 into the support portion 55. This makes the work of attaching the wheel 10 to the frame 50 easier.

[0061] Furthermore, in the electric wheelchair 100, the position of the motor housing 23 in the rotational direction of the wheel 10, or more specifically, the position of the motor housing 23 in the rotational direction relative to the frame 50, may be predetermined. For example, a recess (or protrusion) formed in the frame 50 and a protrusion (or recess) formed in the motor housing 23 may fit together. These recesses and protrusions may then define the position of the motor housing 23 in the rotational direction of the wheel 10. Since the wheel 10 has a stopper member 34, the operator can stop pushing the operating rod 32, hold the wheel 10 with both hands, adjust the position of the motor housing 23 in the rotational direction, and then fit the axle 31 into the support part 55.

[0062] [Movement of stopper member] As shown in Figure 6(a), the axle 31 has a housing hole 31b that intersects with the axis Ax. The stopper member 34 is positioned in the housing hole 31b and is movable in the radial direction of the axle 31. Specifically, the stopper member 34 is movable inside the housing hole 31b between the "stopper position" shown in Figure 6(a) and the "stopper release position" shown in Figure 6(b).

[0063] The stopper position is the position where the stopper member 34 engages with the stopped portion 32c of the operating rod 32. That is, when the stopper member 34 is in the stopper position, the engaging portion 34b fits into the stopped portion 32c. The position of the operating rod 32 is then maintained in the wheel lock release position.

[0064] On the other hand, the stopper release position is the position in which the stopper member 34 does not engage with the stopped portion 32c, or in other words, the position in which the engagement between the two is released. When the stopper member 34 is in the stopper release position, the engaging portion 34b is not fitted into the stopped portion 32c. Therefore, movement of the operating rod 32 from the wheel lock release position to the wheel lock position is permitted.

[0065] As shown in Figure 6(a), a second elastic member 39 is positioned inside the housing hole 31b of the axle 31. The second elastic member 39 biases the stopper member 34 toward the stopper position (the position shown in Figure 6(a)). Therefore, when the operating rod 32 moves to the wheel lock release position (more specifically, the "first position" described later) while the axle 31 is outside the support portion 55, the stopper member 34 engages with the stopped portion 32c due to the elastic force of the second elastic member 39.

[0066] The second elastic member 39 is, for example, a coil spring. The second elastic member 39 is expandable and contractible in the radial direction of the axle 31. The second elastic member 39 is positioned between the base of the stopper member 34 (the part opposite to the interference portion 34e, which will be described later) and the bottom 31c of the housing hole 31b.

[0067] [Interference portion of the stopper member] As shown in Figure 6(a), the stopper member 34 has an interference portion 34e at its tip. The interference portion 34e protrudes from the outer circumferential surface 31g of the axle 31 when the stopper member 34 is in the stopper position. That is, the distance between the tip of the stopper member 34 (the tip of the interference portion 34e) and the axis Ax becomes greater than the distance from the axis Ax to the outer circumferential surface 31g of the axle 31.

[0068] On the other hand, as shown in Figure 6(b), when the stopper member 34 is in the stopper release position, the entire stopper member 34, including the interference portion 34e, fits into the housing hole 31b. That is, the distance between the tip of the stopper member 34 (the tip of the interference portion 34e) and the axis Ax is substantially the same as the distance from the axis Ax to the outer circumferential surface 31g of the axle 31.

[0069] When the stopper member 34 is in the stopper position, the engaging portion 34b engages with the stopped portion 32c of the operating rod 32, and the position of the operating rod 32 is maintained in the wheel lock release position (the "first position" described later). At this time, the interfering portion 34e protrudes from the outer circumferential surface 31g of the axle 31. Therefore, in the process of inserting the axle 31 into the support portion 55 as shown in Figure 9(b), the interfering portion 34e interferes with the support portion 55. Then, the stopper member 34 is pushed by the inner circumferential surface of the support portion 55 against the elastic force of the second elastic member 39 and moves from the stopper position to the stopper release position.

[0070] As described above, a washer 56 may be placed at the end (entrance) of the support portion 55. In this case, during the process of inserting the axle 31 into the support portion 55, the interfering portion 34e first interferes with the washer 56, and the stopper member 34 moves to the stopper release position.

[0071] In this way, the retention of the operating rod 32 in the wheel lock release position by the stopper member 34 is automatically resolved. That is, the retention of the operating rod 32 in the wheel lock release position is resolved without the operator having to move the stopper member 34.

[0072] As shown in Figure 9(b), when the wheel lock member 33 is located inside the support portion 55, the wheel lock member 33 remains attached to the small diameter portion 32b of the operating rod 32. Therefore, in this state, the movement of the operating rod 32 to the wheel lock position due to the elastic force of the first elastic member 38 is restricted by the wheel lock member 33. As shown in Figure 9(c), when the axle 31 is fully fitted into the support portion 55, that is, when the wheel lock member 33 moves beyond the position of the inner end portion 55a of the support portion 55, the operating rod 32 moves to the wheel lock position. The wheel lock member 33 is also pushed by the large diameter portion 32a and moves to the engagement position, engaging with the inner end portion 55a of the support portion 55.

[0073] As shown in Figures 4A and 4B, the interference portion 34e of the stopper member 34 may be, for example, hemispherical. With this shape of the stopper member 34, when the interference portion 34e comes into contact with the washer 56 during the process of inserting the axle 31 into the support portion 55, a force is generated that returns the stopper member 34 to the stopper position (a force acting in the radial direction of the axle 31). In addition, friction between the interference portion 34e and the inner circumferential surface of the support portion 55 can be reduced during the process of removing the axle 31 from the support portion 55 and the process of fitting the axle 31 into the support portion 55.

[0074] The shape of the stopper member 34 is not limited to the example shown in Figure 4A, etc. For example, a slope may be formed at the tip of the stopper member 34. Then, during the process of inserting the axle 31 into the support portion 55, this slope may come into contact with the washer 56, generating a force that returns the stopper member 34 to the stopper position.

[0075] [The first and second positions, which are part of the wheel lock release position] As described above, when the axle 31 is inside the support portion 55, the stopper function of the stopper member 34 (engagement with the operating rod 32) does not work. The structure for this purpose will be described below.

[0076] As described above, when the operating rod 32 is in the wheel lock release position, the position of the small diameter portion 32b coincides with the housing hole 31a in which the wheel lock member 33 is positioned. The wheel lock release position includes a first position of the operating rod 32 shown in Figure 6(a) and a second position of the operating rod 32 shown in Figure 6(b). The first position is, for example, the position in which the operating rod 32 is pushed as far as possible inside the axle 31. The second position is a position slightly back toward the wheel lock position from the first position. As shown in Figures 6(a) and (b), the first position and the second position are shifted by a distance ΔP. The operating rod 32 is biased by the first elastic member 38 from the first position toward the second position.

[0077] As shown in Figures 6(a) and (b), the position of the small-diameter portion 32b of the operating rod 32 coincides with the position of the housing hole 31a, whether the operating rod 32 is in the first position or the second position. As a result, in either state, the wheel lock member 33 is allowed to move from the engaged position to the released position. To allow the operating rod 32 to move between the first and second positions, a clearance is ensured in the axial size L1 of the small-diameter portion 32b (see Figure 6(b)).

[0078] As shown in Figure 6(a), when the operating rod 32 is in the first position, the position of the stoppered portion 32c of the operating rod 32 coincides with the position of the stopper member 34 (more specifically, the position of the engaging portion 34b). Therefore, as shown in the figure, when the operating rod 32 is pushed to the first position with the axle 31 outside the support portion 55, the stopper member 34 moves to the stopper position and engages with the stoppered portion 32c. That is, the engaging portion 34b fits into the stoppered portion 32c. As a result, the operating rod 32 is maintained in the first position.

[0079] On the other hand, when the operating rod 32 is in the second position, as shown in Figure 6(b), the position of the stopped portion 32c is offset from the position of the stopper member 34 (more specifically, the position of the engaging portion 34b). Therefore, the stopper member 34 remains in the stopper release position and does not engage with the stopped portion 32c. That is, the engaging portion 34b does not fit into the stopped portion 32c. As shown in the same figure, a part 34c of the engaging portion 34b of the stopper member 34 is in contact with the outer circumferential surface 32d of the portion between the stopped portion 32c and the small diameter portion 32b. As a result, the operating rod 32 is not maintained in the second position, and movement to the wheel lock position due to the elastic force of the first elastic member 38 is permitted.

[0080] [Movement of the stopper member when the axle is inside the support part] As described above, the stopper member 34 has an interference portion 34e (see Figure 6(a)) at its tip. As shown in Figure 8(a), when the stopper member 34 is inside the support portion 55, the interference portion 34e interferes with the inner circumferential surface of the support portion 55. Therefore, in this state, movement of the stopper member 34 to the stopper position is not permitted. As a result, when the stopper member 34 is inside the support portion 55, the operating rod 32 is not maintained in the first position, but moves to the second position due to the elastic force of the first elastic member 38, as shown in Figure 8(b).

[0081] When the operating rod 32 is in the second position, the stopper member 34 remains in the stopper release position and does not engage with the stopped portion 32c. Therefore, as shown in Figures 7(c) and 8(c), when the axle 31 is disengaged from the support portion 55, the operating rod 32 automatically moves from the wheel lock release position to the wheel lock position due to the elastic force of the first elastic member 38. In other words, the operating rod 32 moves to the wheel lock position without any special work being performed by the operator to return the operating rod 32 to the wheel lock position. The wheel lock member 33 is then positioned in the engagement position, and a portion of the wheel lock member 33 protrudes from the outer circumferential surface 31g of the axle 31.

[0082] Furthermore, if the axle 31 is reinserted into the support portion 55 before the axle 31 is completely removed from the support portion 55, the operating rod 32 automatically returns from the wheel lock release position to the wheel lock position, and the wheel lock member 33 engages with the support portion 55. In other words, the separation of the axle 31 from the support portion 55 is restricted.

[0083] [Engaging portion of stopper member] As shown in Figure 4A, the engaging portion 34b is formed only in a part of the through hole 34a formed in the stopper member 34. In other words, the width of the engaging portion 34b in the axial direction is smaller than the width of the stopper member 34 in the axial direction. Therefore, the stopper member 34 has a guide surface 34f adjacent to the engaging portion 34b on the inner surface of the through hole 34a. This guide surface 34f is a curved surface and, as shown in Figures 6(a) and 4B, is positioned along the outer circumferential surfaces 32d and 32e of the operating rod 32 when the engaging portion 34b is fitted into the stopped portion 32c. When the stopper member 34 is in the stopper position, the guide surface 34f may be in contact with the outer circumferential surfaces 32d and 32e of the operating rod 32. The stopped portion 32c is formed between the two outer circumferential surfaces 32d and 32e. This structure of the stopper member 34 and the operating rod 32 allows for proper positioning of the stopper member 34 when it is in the stopper position.

[0084] If the guide surface 34f is not formed on the inner surface of the through hole 34a, the stopper portion 32c is narrower than the diameter of the through hole 34a, which can cause the orientation of the stopper member 34 within the housing hole 31b to change in an unintended direction. For example, the stopper member 34 may rotate around a center line perpendicular to the axis Ax. In this state of rotation, even if the stopper member 34 moves from the stopper position to the stopper release position, the edge of the through hole 34a of the stopper member 34 may remain caught on the edge of the stopper portion 32c (recess). In that case, the operating rod 32 cannot return from the wheel lock release position to the wheel lock position.

[0085] In contrast, in the wheel 10, as shown in Figure 4B, when the engaging portion 34b is fitted into the stoppered portion 32c, the guide surface 34f is positioned along the outer circumferential surfaces 32d and 32e of the operating rod 32. Therefore, the orientation of the stopper member 34 within the housing hole 31b is optimized. As a result, when the stopper member 34 moves from the stopper position to the stopper release position, the engagement between the stopper member 34 and the stoppered portion 32c is immediately released. Consequently, the operating rod 32 can return more reliably from the wheel lock release position to the wheel lock position.

[0086] Furthermore, the stopper member 34 does not necessarily have an engaging portion 34b that protrudes inward from the through hole 34a. In this case, the inner surface of the through hole 34a may function as an engaging portion that fits into the stoppered portion 32c. [summary] (1) As described above, the wheel 10 includes an axle 31 for fitting inside a support portion 55 provided on the vehicle body, an operating rod 32 inserted inside the axle 31, a first elastic member 38, a wheel lock member 33 that is movable radially on the axle 31 between an engagement position (Figure 5(a)) in which it engages with the support portion 55 and a release position (Figure 5(b)) in which it does not engage with the support portion 55, and a stopper member 34. The operating rod 32 is axially relative to the axle 31 between a wheel lock position (Figure 5(a)) that positions the wheel lock member 33 in the engagement position and a wheel lock release position (Figure 5(b)) that allows the wheel lock member 33 to move to the release position. The operating rod 32 is pushed from the wheel lock release position toward the wheel lock position by the elastic force of the first elastic member 38, and can be moved from the wheel lock position toward the wheel lock release position by being pushed by the user. The stopper member 34 engages with the operating rod 32 when the operating rod 32 is in the wheel lock release position, and maintains the operating rod 32 in the wheel lock release position against the elastic force of the first elastic member 38.

[0087] With this wheel 10, when an operator attaches the wheel 10 to the frame 50, the stopper member 34 temporarily maintains the position of the operating rod 32 in the wheel lock release position, so the operator can stop pushing the operating rod 32. As a result, the operator can hold the wheel 10 with both hands and fit the axle 31 into the support part 55. This makes the process of attaching the wheel 10 to the frame 50 easier.

[0088] (2) In the wheel of (1), the stopper member 34 is positioned in a housing hole 31b formed in the axle 31 and can move radially within the housing hole 31b of the axle 31. A stoppered portion 32c is formed on the operating rod 32. The stopper member 34 engages with the stoppered portion 32c when the operating rod 32 is in the wheel unlocked position, and maintains the operating rod 32 in the wheel unlocked position.

[0089] In the wheel of (3)(2), the stopper member 34 has a through hole 34a that penetrates the stopper member 34 in the axial direction. The operating rod 32 extends axially through the through hole 34a. The stopper member 34 has an engaging portion 34b inside the through hole 34a that engages with the stopped portion 32c. By forming a through hole 34a in the stopper member 34 in this way, a rod with a small diameter can be used as the operating rod 32.

[0090] In the wheel described in (4)(2) or (3), when the operating rod 32 is in the wheel unlock position and the axle 31 is inside the support portion 55, the stopper member 34 does not engage with the stoppered portion 32c. This structure prevents the operating rod 32 from being maintained in the wheel unlock position in a situation unintended by the operator. For example, if the axle 31 is reinserted into the support portion 55 before the axle 31 is completely withdrawn from the support portion 55, the operating rod 32 will not be maintained in the wheel unlock position, and the operating rod 32 may automatically return to the wheel lock position.

[0091] In the wheel described in any of (5)(2) to (4), the wheel lock release position includes a first position (Figure 6(a)) and a second position (Figure 6(b)) which is closer to the wheel lock position than the first position. The operating rod 32 is pushed from the first position to the second position by the first elastic member 38. When the operating rod 32 is in the first position, the operating rod 32 allows the wheel lock member 33 to move to the release position, and the stopper member 34 engages with the stopped portion 32c, maintaining the operating rod 32 in the first position. When the operating rod 32 is in the second position, the operating rod 32 allows the wheel lock member 33 to move to the release position, and the stopper member 34 is not engaged with the stopped portion 32c. With this structure, by positioning the operating rod 32 in the second position, it is possible to allow the wheel lock member 33 to move to the release position while preventing the position of the operating rod 32 from being maintained in the wheel lock release position.

[0092] In the wheel described in (6)(5), when the stopper member 34 is inside the support portion 55 together with the axle 31, the operating rod 32 is not maintained in the first position, but moves to the second position due to the elastic force of the first elastic member 38. With this structure, when the stopper member 34 is inside the support portion 55 together with the axle 31, it is possible to prevent the position of the operating rod 32 from being maintained in the wheel lock release position by the action of the stopper member 34.

[0093] In the wheel described in (7), (5), or (6), the stopper member 34 is movable in the radial direction of the axle 31 between a stopper position in which the stopper member 34 engages with the stopped portion 32c and maintains the operating rod 32 in a first position, and a stopper release position in which the engagement between the stopper member 34 and the stopped portion 32c is released. The stopper member 34 is biased from the stopper release position to the stopper position by the elastic force of the second elastic member 39. When the stopper member 34 is inside the support portion 55 together with the axle 31, its movement from the stopper release position to the stopper position is restricted. This structure prevents the position of the operating rod 32 from being maintained in the wheel lock release position by the action of the stopper member 34 when the stopper member 34 is inside the support portion 55. Furthermore, when the stopper member 34 is outside the support portion 55, the stopper member 34 moves to the stopper position due to the elastic force of the second elastic member 39, and as a result, the position of the operating rod 32 can be maintained in the wheel lock release position.

[0094] In the wheel described in (8)(7), the stopper member 34 has an interference portion 34e that protrudes from the outer circumferential surface of the axle 31 when the stopper member 34 is in the stopper position. When the stopper member 34 is inside the support portion 55 together with the axle 31, the interference portion 34e interferes with the inner circumferential surface of the support portion 55, restricting the movement of the stopper member 34 from the stopper release position to the stopper position. With this structure, when the stopper member 34 is inside the support portion 55, it is possible to prevent the position of the operating rod 32 from being maintained in the wheel lock release position by the action of the stopper member 34. Also, when the stopper member 34 is outside the support portion 55, the stopper member 34 moves to the stopper position due to the elastic force of the second elastic member 39, and as a result, the position of the operating rod 32 can be maintained in the wheel lock release position.

[0095] (9) In the wheel 10 described in any of (1) to (8), when the axle 31 is inserted into the support portion 55 while the operating rod 32 is in the wheel lock release position, the maintenance of the operating rod 32 in the wheel lock release position is automatically released. This structure makes the work of attaching the wheel 10 to the vehicle body simpler.

[0096] In the wheel 10 described in any of (10)(2) to (8), the stopper member 34 is movable in the radial direction of the axle 31 between a stopper position in which the stopper member 34 engages with the stopped portion 32c and maintains the operating rod 32 in the hole-lock release position, and a stopper release position in which the engagement between the stopper member 34 and the stopped portion 32c is released. The stopper member 34 has an interference portion 34e that protrudes from the outer circumferential surface 31g of the axle 31 when the stopper member 34 is in the stopper position. The interference portion 34e is pushed by the inner circumferential surface of the support portion 55, moving the stopper member 34 from the stopper position to the stopper release position. As a result, when the axle 31 is inserted inside the support portion 55, the operating rod 32 can automatically return to the wheel-lock position.

[0097] In the wheel 10 described in any of (11)(1) to (10), when the wheel is in the wheel locked position, the operating rod 32 pushes the wheel lock member 33 radially outward from the axle 31 so that the wheel lock member 33 engages with the support portion 55, and when the wheel is in the unlocked position, the operating rod 32 allows the wheel lock member 33 to sink toward the radial center of the axle 31.

[0098] In the wheel 10 described in (12)(11), the operating rod 32 has a large-diameter portion 32a and a small-diameter portion 32b that are separated in the axial direction. The large-diameter portion 32a pushes the wheel lock member 33 radially outward from the axle 31 and restricts the radial movement of the wheel lock member 33 when the operating rod 32 is in the wheel lock position. The small-diameter portion 32b allows the wheel lock member 33 to sink toward the radial center of the axle 31 when the operating rod 32 is in the wheel unlock position.

[0099] Furthermore, the wheel and electric wheelchair proposed in this disclosure are not limited to the wheel 10 and electric wheelchair 100 described above, and various modifications may be made.

[0100] For example, the structure that restricts the stopper member 34 from engaging with the operating rod 32 when the axle 31 is fitted inside the support portion 55 is not limited to the structure of the wheel 10 described above (specifically, the operating rod 32 positioned in the second location and the interference portion 34e of the stopper member 34), but may be modified as appropriate.

[0101] Furthermore, the structure for the stopper member 34 to automatically return to the stopper release position when the axle 31 is fitted into the support portion 55 is not limited to the structure of the wheel 10 (specifically, the interference portion 34e of the stopper member 34), but may be modified as appropriate. For example, instead of the interference portion 34e of the stopper member 34, a protrusion may be formed on the inner surface of the support portion 55 to push the stopper member 34 toward the stopper release position. [Explanation of symbols]

[0102] 10: Wheel, 11: Tire, 12: Handrim, 13: Cover, 14: Rim, 15: Hub, 15a: Outer circumference, 15b: Side, 16: Spoke, 20: Electric motor, 21: Rotor, 22: Stator, 23: Motor housing, 31: Axle, 31a: Housing hole, 31b: Housing hole, 31c: Bottom, 31e: Receiving surface, 31g: Outer circumference, 32: Operating rod, 32a: Large diameter part, 32b: Small diameter part, 32c: Stoppered part, 32d·32e: Outer circumference, 33: Wheel locking member, 34: Stopper member, 34a: Through hole, 34b: Engaging part, 34e: Interference part, 34f: Guide surface, 35: Stopper ring, 37: Operation button, 38: First elastic member, 39: Second elastic member, 40: Reduction mechanism, 41: Rotating shaft, 50: Frame, 51: Rear frame part, 52: Seat frame part, 53: Lower frame part, 54: Sleeve, 55: Support part, 55a: Inner end part, 56: Washer, 61: Foot support, 62: Seat, 63: Back support, 64: Arm support, 65: Operation part, 65a: Joystick, 66: Caster, 71: Battery, 72: Battery holder, 100: Electric wheelchair.

Claims

1. Wheels that can be attached to and removed from the frame of an electric wheelchair, A cylindrical axle for fitting inside a cylindrical support portion provided on the vehicle body, An operating rod inserted inside the cylindrical axle, First elastic member and A wheel locking member is provided that is movable in the radial direction of the cylindrical axle between an engagement position in which it engages with the cylindrical support portion and a release position in which it does not engage with the cylindrical support portion. Stopper member and It has, The operating rod is axially movable relative to the cylindrical axle between a wheel lock position that positions the wheel lock member in the engagement position and a wheel unlock position that allows the wheel lock member to move to the unlock position. The operating rod is pushed from the wheel lock release position toward the wheel lock position by the elastic force of the first elastic member, and is movable from the wheel lock position toward the wheel lock release position by being pushed by the user. The stopper member engages with the operating rod when the operating rod is in the wheel lock release position and maintains the operating rod in the wheel lock release position against the elastic force of the first elastic member. Wheels for an electric wheelchair.

2. The stopper member is positioned in a housing hole formed in the cylindrical axle and is capable of moving within the housing hole in the radial direction of the cylindrical axle. A stopper portion is formed on the aforementioned operating rod. The stopper member engages with the stopped portion when the operating rod is in the wheel lock release position, thereby maintaining the operating rod in the wheel lock release position. A wheel for an electric wheelchair as described in claim 1.

3. The stopper member has a through hole that penetrates the stopper member in the axial direction. The operating rod extends axially through the through hole, The stopper member has an engaging portion on the inside of the through hole that engages with the portion to be stopped. A wheel for an electric wheelchair as described in claim 2.

4. When the operating rod is in the wheel lock release position and the cylindrical axle is inside the cylindrical support portion, the stopper member does not engage with the portion to be stopped. A wheel for an electric wheelchair as described in claim 1.

5. The wheel lock release position includes a first position and a second position which is closer to the wheel lock position than the first position. The operating rod is pushed by the first elastic member from the first position toward the second position, When the operating rod is in the first position, the operating rod allows the wheel lock member to move to the release position, the stopper member engages with the stopped portion, and maintains the operating rod in the first position. When the operating rod is in the second position, the operating rod allows the wheel lock member to move to the release position, and the stopper member is not engaged with the stopped portion. A wheel for an electric wheelchair as described in claim 2.

6. When the stopper member is located inside the cylindrical support portion together with the cylindrical axle, the operating rod is not maintained in the first position, but moves to the second position due to the elastic force of the first elastic member. A wheel for an electric wheelchair as described in claim 5.

7. The stopper member is movable in the radial direction of the cylindrical axle between a stopper position in which the stopper member engages with the portion to be stopped and maintains the operating rod in the first position, and a stopper release position in which the engagement between the stopper member and the portion to be stopped is released. The stopper member is biased from the stopper release position to the stopper position by the elastic force of the second elastic member. When the stopper member is located inside the cylindrical support portion together with the cylindrical axle, movement from the stopper release position to the stopper position is restricted. A wheel for an electric wheelchair as described in claim 5.

8. The stopper member has an interference portion that protrudes from the outer circumferential surface of the cylindrical axle when the stopper member is in the stopper position. When the stopper member is located inside the cylindrical support portion together with the cylindrical axle, the interfering portion interferes with the inner circumferential surface of the cylindrical support portion, thereby restricting the movement of the stopper member from the stopper release position to the stopper position. A wheel for an electric wheelchair as described in claim 7.

9. As the cylindrical axle is inserted into the cylindrical support portion while the operating rod is in the wheel lock release position, the retention of the operating rod in the wheel lock release position is automatically released. A wheel for an electric wheelchair as described in claim 1.

10. The stopper member is movable in the radial direction of the cylindrical axle between a stopper position in which the stopper member engages with the portion to be stopped and maintains the operating rod in the hole-lock release position, and a stopper release position in which the engagement between the stopper member and the portion to be stopped is released. The stopper member has an interference portion that protrudes from the outer circumferential surface of the cylindrical axle when the stopper member is in the stopper position. The interfering portion is pressed by the inner circumferential surface of the cylindrical support portion, causing the stopper member to move from the stopper position to the stopper release position. A wheel for an electric wheelchair as described in claim 2.

11. When the operating rod is in the wheel lock position, it pushes the wheel lock member outwards in the radial direction of the cylindrical axle so that the wheel lock member and the cylindrical support portion engage. When the operating rod is in the wheel lock release position, the wheel lock member is allowed to sink toward the radial center of the cylindrical axle. A wheel for an electric wheelchair as described in claim 1.

12. The operating rod has a large diameter portion and a small diameter portion that are separated in the axial direction. The large-diameter portion pushes the wheel lock member outward in the radial direction of the cylindrical axle and restricts the radial movement of the wheel lock member when the operating rod is in the wheel lock position. The small diameter portion allows the wheel locking member to sink toward the radial center of the cylindrical axle when the operating rod is in the wheel lock release position. A wheel for an electric wheelchair as described in claim 11.

13. An electric wheelchair having the wheels described in claim 1.

Images