Mounting structure of footrest for wheelchair

Abstract

To provide a footrest mounting structure allowing a user to adjust an installation angle of the footrest with easy operation.SOLUTION: A footrest mounting structure 39 comprises a first connecting member 50, a second connecting member 65, and press-contact means 81 for press-contacting the mating surfaces of the pair of connecting members. The press-contact means 81 includes a male screw member 90 screwing with the first connecting member 50, an operation part 86 for rotating the male screw member 90, and a contact part 84 coming into contact with an end on the opposite side to the mating surface 69 of the second connecting member 65. The mating surfaces 56 and 69 of the first connecting member 50 and the second connecting member 65 have a plurality of engagement teeth in an annular shape in plan view, where a locked state in which rotation of the first connecting member 50 is restricted by the engagement of the engagement teeth of the pair of connecting members 50 and 65 and an unlocked state in which the rotation of the first connecting member 50 is permitted by disengagement of the engagement teeth are changed over by rotational operation of the operation part 86.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a mounting structure for a wheelchair footrest, and more particularly to a mounting structure for a wheelchair footrest that allows the installation angle of the wheelchair footrest to be adjusted. [Background technology]

[0002] The angle of the footrest on a wheelchair can be adjusted to suit the wheelchair user. The following Patent Document 1 discloses an example of a footrest mounting structure that allows the installation angle of the footrest to be changed. This Patent Document 1 discloses that an angle adjustment mechanism made of a clamp is interposed between the frame side member of the wheelchair and the footrest, and when adjusting the angle of the footrest, a fastening bolt is loosened at the fastening part of the clamp to either the frame side member or the footrest, and the fastening bolt is tightened after the angle is adjusted.

[0003] However, in such a footrest mounting structure, tools such as a screwdriver and a wrench are required to adjust the installation angle. Considering that many wheelchair users are elderly or physically disabled, it is desirable to be able to adjust the installation angle of the footrest with easier operations. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2008-279240 A Summary of the Invention [Problem to be solved by the invention]

[0005] SUMMARY OF THE PRESENT DISCLOSURE ... In view of the above circumstances, the present invention has been made with an object to provide a footrest mounting structure that allows the installation angle of the footrest to be adjusted with a simple operation. [Means for solving the problem]

[0006] The footrest mounting structure according to the first aspect of the present invention is defined as follows: a first connecting member attached to the footrest; a second connecting member attached to the footrest support rod; and a pressing means for pressing the mating surfaces of the pair of connecting members against each other, the pressing means includes a male screw member that penetrates the second connecting member and screws into the first connecting member, an operating portion that rotates the male screw member integrally, and an abutment portion that abuts against an end portion of the second connecting member opposite to the mating surface portion, A plurality of engagement teeth are provided on mating surfaces of the first connecting member and the second connecting member around the axis of the male screw member in a ring-like or arc-like shape in a plan view, The operating unit can be rotated to switch between a locked state in which the engagement teeth of the pair of connecting members engage to restrict rotation of the first connecting member around the axis, and an unlocked state in which the engagement teeth are released from each other to allow rotation of the first connecting member around the axis.

[0007] According to the wheelchair footrest mounting structure of the first aspect defined in this manner, the footrest can be rotated together with the first connecting member around the axis of the male screw member by rotating the operating part constituting a part of the pressing means in the direction in which the screw loosens, and the footrest can be fixed so that it cannot rotate by rotating the operating part in the direction in which the screw tightens. In other words, the installation angle of the footrest can be adjusted by the simple operation of rotating the operating part constituting a part of the pressing means without using a separate tool.

[0008] Here, a plurality of spring members that bias the pair of connecting members in a direction separating them from each other can be provided at different circumferential positions around the axis of the male screw member (second aspect). In this way, the gap between the first connecting member and the second connecting member in the unlocked state can be easily maintained substantially constant in the circumferential direction, allowing the first connecting member 50 to rotate without interference without making the gap excessively large.

[0009] In addition, in this invention, the male thread member can be configured to pass through insertion holes formed in the operating member on which the operating portion is provided, the second connecting member, and the footrest support rod, and to be screwed into the female thread hole of the first connecting member (third aspect). In this way, a structure that enables the footrest to rotate around an axis perpendicular to the footrest support rod can be realized with a small number of parts. [Brief description of the drawings]

[0010] [Figure 1] 1 is a side view of a wheelchair equipped with a footrest mounting structure according to one embodiment of the present invention; [Diagram 2] FIG. 2 is an enlarged view of the footrest and its surrounding area in FIG. [Diagram 3] 4 is a cross-sectional view of the mounting structure for the footrest of the embodiment in a locked state. FIG. [Figure 4] FIG. 4 is an exploded view of the mounting structure of the footrest according to the embodiment. [Diagram 5] FIG. 2 is a plan view of the footrest and the first connecting member. [Figure 6] FIG. 2 is a perspective view showing the footrest mounting structure of the embodiment separated at a mating surface. [Figure 7] 4 is a cross-sectional view of the footrest mounting structure of the embodiment in an unlocked state. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a side view of a wheelchair equipped with a footrest mounting structure according to an embodiment of the present invention. The wheelchair 10 includes left and right frames 12, a flexible cloth seat 14 disposed between the frames 12, and left and right front wheels 16 and rear wheels 17 attached to the frames 12. In this specification, left and right refer to the left and right of a wheelchair user seated in the wheelchair 10, and front and rear refer to the front and rear of a wheelchair user seated in the wheelchair 10. FIG. 1 shows only the left side of the wheelchair 10, but the right side of the wheelchair 10, not shown, also includes a frame 12, a front wheel 16, and a rear wheel 17 that are symmetrical to the left side of FIG. 1.

[0012] Each frame 12 includes an upper rod-shaped member 19 extending in the front-rear direction and having an arm support (armrest portion) 18 attached to its upper surface, an intermediate rod-shaped member 20 disposed below the upper rod-shaped member 19 and extending in the front-rear direction, a front rod-shaped member 21 connected to the front end of the intermediate rod-shaped member 20 and extending in the vertical direction, a lower rod-shaped member 23 disposed below the intermediate rod-shaped member 20, extending in the front-rear direction and having its front portion connected to the front rod-shaped member 21, and a rear rod-shaped member 24 extending in the vertical direction and connecting the rear portion of the lower rod-shaped member 23 to the rear end of the intermediate rod-shaped member 20 and the rear end of the upper rod-shaped member 19 and erected behind the seat 14. These rod-shaped members constituting part of the frame 12 are made of metal pipes.

[0013] The left and right rear rod-like members 24, 24 are fitted with corresponding ends of a flexible cloth back support 29. The back support 29 constitutes a backrest against which a wheelchair user leans.

[0014] In the figure, reference numeral 27 denotes a push handle made of resin that is grasped by the caregiver when moving the wheelchair 10. The push handle 27 is supported by the rear rod-shaped members 24 that extend upward.

[0015] An axle support hole (not shown) is provided in the lower part of each rear rod-shaped member 24, and the axle of the rear wheel 17 is fitted into the axle support hole to support the rear wheel 17 for free rotation. The rear wheel 17 in this example includes a rubber or resin tire 28 mounted on the outer periphery of a hard rim 17b.

[0016] A crossbar 31 having an X-shape in a front view is disposed between the left and right frames 12, 12, and the left and right frames 12, 12 are connected to each other via each crossbar 31 in a foldable manner.

[0017] An inverted L-shaped footrest support rod 25 is connected to each front rod-shaped member 21, and a footrest (footrest portion) 26 is attached to the lower end of each footrest support rod 25. The following describes the footrest support rod 25 and footrest 26 on the left side shown in FIG. 1, but the same applies to the footrest support rod 25 and footrest 26 on the right side, which is shaped symmetrically to the left side in FIG.

[0018] The footrest support rod 25 is a rod-shaped member to which the footrest 26 is attached, and is composed of a lower support rod 33 and an upper support rod 37, and these rod-shaped members 33, 37 are made of metal pipes. The upper support rod 37 constitutes the upper member of the footrest support rod 25, and its upper end is connected to the front rod-shaped member 21 as shown in Fig. 1. The upper support rod 37 has an inner diameter slightly larger than the outer diameter of the lower support rod 33, so that the lower support rod 33 can be slidably inserted into the upper support rod 37. The lower support rod 33 constitutes the lower member of the footrest support rod 25, and the footrest 26 is attached to its lower end. A clamp device 38 is attached to the end of the upper support rod 37, and after sliding the lower support rod 33 up and down, it is fixed so that it cannot slide, making it possible to adjust the footrest 26 to any desired height.

[0019] As shown in FIG. 5, the footrest 26 is composed of a footrest body 40, and sleeve portions 41 and 42 which are arranged separately in the front-rear direction along the axial direction of a mounting shaft 45 and through which the mounting shaft 45 can be inserted. The footrest body 40 and the front and rear sleeves 41, 42 are made of hard synthetic resin such as polyacetal. The footrest body 40 may be provided with recesses for reducing weight and ribs for increasing rigidity. Furthermore, the top surface 40a that comes into contact with the feet of the wheelchair user may be provided with protrusions to prevent slipping.

[0020] In this embodiment, as shown in Fig. 4, for example, the footrest 26 is attached to the lower support rod 33 so that the installation angle of the footrest 26 can be adjusted (for example, as shown by the two-dot chain line in Fig. 2) under a mounting structure including the first connecting member 50, the second connecting member 65, and the pressing means 81. The mounting structure 39 for the footrest will be described in detail below.

[0021] 4, the footrest 26 is attached to the first connecting member 50 via a mounting shaft 45, and the footrest 26 is rotatable around the mounting shaft 45. In the use state, the outer surface 43 of the footrest body 40 abuts against the outer wall of the first connecting member 50, and the position of the footrest 26 around the mounting shaft 45 is regulated so that the upper surface 40a is approximately horizontal.

[0022] The first connecting member 50 is composed of a tubular portion 52 having a through hole 51 formed therein for inserting the mounting shaft 45 therethrough, and a disk-shaped portion 55 (see FIG. 5) that is approximately parallel to the mounting shaft 45. The portion of the disk-shaped portion 55 opposite the cylindrical portion 52 serves as a first mating surface portion 56 that comes into contact with a second connecting member 65 (see FIG. 4). The first mating surface portion 56 has a circular shape in a plan view, and a female screw hole 57 that screws into a male screw member 90 (described later) is formed in the center thereof in a manner that protrudes from the peripheral portion. A circular flat portion 58 is formed on the outside of the female screw hole 57 and is concentric with the female screw hole 57.

[0023] 6, an interlocking portion 60 having a plurality of engagement teeth 59 formed in an annular shape in a plan view is provided on the outer side of the flat portion 58. An annular flange portion 61 is formed further outboard of the interlocking portion 60, protruding toward the opposing second connecting member 65 and covering a portion of the second connecting member 65. The flange portion 61 also functions as a guide when the first connecting member 50 is rotated.

[0024] The second connecting member 65 is a truncated cone-shaped member attached to the end of the lower support rod 33. An upwardly opening fitting hole 66 is formed on the outer circumferential surface of the second connecting member 65, into which the end of the lower support rod 33 can be inserted. An inwardly protruding engagement protrusion 67 is formed on the inner circumferential surface of the fitting hole 66, as shown in the balloon view of Fig. 4, in a manner extending in the vertical direction. Engagement grooves 34, 34 extending in the axial direction (longitudinal direction) are formed on the left and right sides of the lower support rod 33, and the engagement protrusion 67 engages with the engagement groove 34 of the lower support rod 33 inserted into the mating hole 66, thereby regulating the orientation of the lower support rod 33.

[0025] A portion of the second connecting member 65 that faces the first mating surface 56 of the first connecting member 50 is a second mating surface 69. The second mating surface 69 is circular in plan view, and has an insertion hole 70 formed in the center thereof, through which the male screw member 90 is inserted in the thickness direction of the second connecting member 65. The opening 70a of the insertion hole 70 on the second mating surface portion 69 side is sized to fit with the peripheral portion 57a ​​of the female threaded hole 57 on the first connecting member 50 side, and the opening 70b on the opposite side of the insertion hole 70 is sized to fit with the annular protrusion 85a of the operating member 82.

[0026] 6, in the second mating surface portion 69, a circular flat portion 72 is formed outside the insertion hole 70 and concentric with the insertion hole 70. Two recessed holes 73, 73 for accommodating the spring member 96 are formed on either side of the insertion hole 70 in the flat portion 72. The spring member 96 housed in the recess 73 has one end abutting against the bottom surface of the recess 73 and the other end abutting against the flat portion 58 of the first connecting member 50, biasing the pair of connecting members 50 and 65 in a direction separating them from each other.

[0027] 6, an interlocking portion 76 having a plurality of engagement teeth 75 formed in a ring shape in a plan view is provided on the outside of the flat portion 72. In this example, the engagement teeth 59 of the first connecting member 50 and the engagement teeth 75 of the second connecting member 65, which are arranged opposite to each other, are brought into an interlocking state, thereby restricting relative rotation between the first connecting member 50 and the second connecting member 65.

[0028] 4, the portion of the second connecting member 65 opposite the second mating surface portion 69 is an abutted portion 80 that abuts against the opposing operating member 82. The abutted portion 80 is circular in plan view, and the other surfaces are recessed relative to the periphery.

[0029] The operation member 82 is a substantially disk-shaped member and has an outer circumferential surface 82a that is inclined continuously from the second connecting member 65 when combined with the second connecting member 65. The outer circumferential surface 82a is inclined radially inward toward the tip side. The portion of the operating member 82 on the right side in the figure that faces the second connecting member 65 is an abutting portion 84 that abuts against the abutted portion 80 of the second connecting member 65. The abutting portion 84 has a stepped convex shape that corresponds to the shape of the abutted portion 80 of the second connecting member 65, and the operating member 82 is configured to be relatively rotatable about the axis while in abutment against the second connecting member 65. An insertion hole 85 for inserting a male screw member 90 is formed in the center of the operation member 82 so as to penetrate the member in the thickness direction.

[0030] The tip side (left side in the figure) portion of the operating member 82, including the outer circumferential surface 82a, is configured as an operating portion 86 that rotates the male screw member 90 integrally. A recess 87 that is hexagonal in plan view and fits with a head 93 of the male screw member 90 is provided at the end (tip) of the insertion hole 85 opposite to the abutment portion 84.

[0031] The male screw member 90 is a bolt having a shaft 92 with a male screw portion 91 formed at the tip side and a hexagonal head 93. The male screw member 90 is inserted through the insertion holes 85, 70 and 35 formed in the operation member 82, the second connecting member 65 and the lower support rod 33, respectively, and the male screw portion 91 is screwed into the female screw hole 57 of the first connecting member 50. At this time, the shaft 92 of the male screw member 90 extends toward the inside in the left-right direction of the wheelchair 10, and the operation unit 86 is disposed on the outside in the left-right direction of the wheelchair 10. The male screw member 90 and the operating member 82 are members that constitute a pressing means 81 that presses the mating surfaces 56, 69 of the pair of connecting members 50, 65 against each other.

[0032] In the footrest mounting structure 39 of this embodiment configured as described above, when the male screw member 90 is rotated in the tightening direction by operating the operating portion 86, the mating surfaces 56, 69 of the pair of connecting members 50, 65 are pressed against each other, resulting in the locked state shown in Fig. 3. At this time, the engagement teeth 59, 75 of the pair of connecting members 50, 65 mesh with each other, restricting the rotation of the male screw member 90 around the axis P of the first connecting member 50, and the footrest 26 is fixed at a predetermined installation angle.

[0033] On the other hand, in the locked state shown in Fig. 3, when the male screw member 90 is rotated in the loosening direction by operating the operating portion 86, the screwing position changes, and as shown in Fig. 7, a gap δ is generated between the engagement teeth 59, 75 of the pair of connecting members 50, 65, and the engagement between the engagement teeth is released (at this time, the engagement between the male screw member 90 and the female screw hole 57 is maintained). This state is the unlocked state. In this state, rotation of the first connecting member 50 about the axis P is permitted. That is, the installation angle of the footrest 26 can be adjusted about the axis P. In this embodiment, the biasing force of the spring members 96, 96 makes it easier to ensure a uniform gap δ in the circumferential direction between the pair of connecting members 50, 65, so that the first connecting member 50 can be rotated without interference without making the gap excessively large.

[0034] As described above, in the footrest mounting structure 39 of this embodiment, the footrest 26 can be rotated together with the first connecting member 50 around the axis of the male screw member 90 by rotating the operation unit 86 that constitutes a part of the pressing means 81 in a direction that loosens the screw, and the footrest 26 can be fixed so that it cannot rotate by rotating the operation unit 86 in a direction that tightens the screw. In other words, the installation angle of the footrest 26 can be adjusted by the simple operation of rotating the operation unit 86 that constitutes a part of the pressing means, without using a separate tool.

[0035] Furthermore, in the footrest mounting structure 39 of this embodiment, the two spring members 96, 96 that bias the pair of connecting members 50, 65 in a direction separating them from each other are provided at different circumferential positions around the axis of the male thread member 90. Therefore, the biasing force of the spring members 96, 96 makes it easier to ensure a uniform gap δ in the circumferential direction between the pair of connecting members 50, 65, and the first connecting member 50 can be rotated relative to the second connecting member 65 without interference without making the gap excessively large.

[0036] In addition, in the footrest mounting structure 39 of this embodiment, the male threaded member 90 is inserted through the insertion holes 85, 70 and 35 formed in the operating member 82, the second connecting member 65 and the footrest support rod 33, respectively, and is screwed into the female threaded hole 57 of the first connecting member 50, so that a configuration that allows the footrest 26 to rotate around the axis P perpendicular to the footrest support rod 33 can be realized with a small number of parts.

[0037] Although the embodiment of the present invention has been described in detail above, these are merely examples. For example, in the above embodiment, two spring members are provided around the axis of the male screw member, but it is also possible to arrange three or more spring members at equal intervals in the circumferential direction. In addition, in the above embodiment, the engaging teeth are provided in a ring shape when viewed from above on each mating surface of a pair of connecting members, but it is also possible to provide the engaging teeth on both mating surfaces or on either one of the mating surfaces in an arc shape. For example, the present invention can be embodied in various modified forms within the scope of its spirit. [Explanation of symbols]

[0038] 10. Wheelchair 25 Footrest support rod 26 Footrest 33 Lower support rod (footrest support rod) 34 Engagement groove 35,70,85 Through hole 39 Mounting structure 50 First connecting member 56 First mating surface 59,75 Engagement teeth 65 Second connecting member 69 Second mating surface 80 Abutted part 81 Pushing means 82 Operating parts 84 Contact part 86 Control section 90 Male threaded member 96 Spring parts

Claims

1. a first connecting member attached to the footrest; a second connecting member attached to the footrest support rod; and a pressing means for pressing the mating surfaces of the pair of connecting members against each other, the pressing means includes a male screw member that penetrates the second connecting member and screws into the first connecting member, an operating portion that rotates the male screw member integrally, and an abutment portion that abuts against an end portion of the second connecting member opposite to the mating surface portion, A plurality of engagement teeth are provided on mating surfaces of the first connecting member and the second connecting member around the axis of the male screw member in a ring-like or arc-like shape in a plan view, A mounting structure for a wheelchair footrest, in which a locked state in which the engagement teeth of the pair of connecting members engage with each other to restrict rotation of the first connecting member about the axis, and an unlocked state in which the engagement teeth are released from each other to allow rotation of the first connecting member about the axis, can be switched by rotating the operating unit.

2. 2. The mounting structure for a wheelchair footrest according to claim 1, wherein a plurality of spring members for biasing the pair of connecting members in a direction separating them from each other are provided at different circumferential positions around the axis of the male screw member.

3. 3. The mounting structure for a wheelchair footrest as claimed in claim 1, wherein the male screw member is inserted through insertion holes formed in an operating member having the operating portion, the second connecting member and the footrest support rod, and is screwed into a female screw hole of the first connecting member.

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