Footrest support mechanism

Abstract

To provide a footrest support mechanism with a novel configuration which can adjust the footrest at an optional height with easy operation.SOLUTION: A footrest support mechanism 32 includes: a footrest support rod 25 having a first rod-like member 33 and a second rod-like member 37 in which the first rod-like member 33 is inserted and fitted into the inside thereof in a slidable manner; and a clamp device 46 attached to the second rod-like member 37 and holding the first rod-like member 33 in an unslidable manner. The second rod-like member 37 includes elastically deformable parts 40a, 40b which can elastically deforms in a plate thickness direction. The clamp device 46 includes: a holding part 48 for holding the elastically deformable part; and a lever mechanism part 61 which deforms the holding part 48 in a diameter-shrink direction along with rotation of a lever body 62. The rotation of the lever body 62 allows switching between: a lock state in which the elastically deformable parts 40a, 40b are brought into pressure contact with the first rod-like member 33 to hold the first rod-like member 33 at a desired position; and a lock cancel state in which slide of the first rod-like member 33 is permitted.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a footrest support mechanism, and more particularly to a footrest support mechanism that enables adjustment of the height of a footrest of a wheelchair. [Background technology]

[0002] In wheelchairs, the height of the footrest (foot rest) is adjusted according to the length of the wheelchair user's lower legs. For this reason, wheelchairs are provided with a mechanism for adjusting the height of the footrest. For example, a structure is known in which multiple adjustment holes are provided along the longitudinal direction of the leg frame that supports the footrest, and the footrest is directly fastened to one selected from these adjustment holes via a bolt. However, considering that many wheelchair users are elderly or physically disabled, it is desirable to be able to adjust the footrest to any height with a simpler operation.

[0003] The footrest support structure in Patent Document 1 below discloses that a sliding frame to which a footrest is attached is inserted slidably into the leg frame of a wheelchair, and a lock pin is inserted into one of a number of adjustment holes formed in the sliding frame to temporarily fix the sliding frame at a predetermined height, and the footrest is fixed at a predetermined height by pressing the sliding frame against the leg frame via a pressing member. The footrest support structure described in Patent Document 1 requires the operation of two types of levers, a height adjustment lever for inserting / removing the lock pin into / from the adjustment hole, and a lock lever for pressing the pressing member against the sliding frame, and therefore improvement is desired in terms of ease of operation. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-176549 A Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in light of the above circumstances, with an object to provide a novel footrest support mechanism that allows the footrest to be adjusted to any height with a simple operation. [Means for solving the problem]

[0006] The footrest support mechanism according to the first aspect of the present invention is defined as follows: a footrest support rod having a first rod-shaped member and a second rod-shaped member into which the first rod-shaped member is slidably inserted; a clamp device attached to the second rod-shaped member and configured to non-slidably hold the first rod-shaped member; A footrest support mechanism for a wheelchair, comprising: The second rod-shaped member has an elastic deformation portion that is elastically deformable in a plate thickness direction, The clamp device includes a holding portion that contains the elastic deformation portion, and a lever mechanism that deforms the holding portion in a diameter reducing direction in accordance with a rotation of a lever body, By rotating the lever body, it is possible to switch between a locked state in which the elastic deformation portion is pressed against the first rod-shaped member to hold the first rod-shaped member in a desired position, and an unlocked state in which the first rod-shaped member is allowed to slide.

[0007] According to the footrest support mechanism of the first aspect thus defined, the height of the footrest can be adjusted steplessly by rotating a single type of lever body without using tools or the like.

[0008] Here, the clamp device is provided with a pair of pressure-receiving pieces arranged opposite to each other with a gap therebetween at each end of the holding portion, The lever mechanism portion is a lever body having a pressing portion for pressing an outer surface of one of the pressure-receiving pieces; A shaft pin that rotatably supports the lever body; It can be configured to include a connecting rod that is arranged across the pair of pressure-receiving pieces, one end of which is connected to the pivot pin and the other end of which faces the outer surface of the other pressure-receiving piece (second aspect).

[0009] In the present invention, a pair of the elastic deformation portions are provided with their free ends closely facing each other, The clamp device can be attached so that the gap between the pair of pressure-receiving pieces and the gap between the pair of elastically deforming portions overlap (third aspect). In this way, the pair of elastically deforming portions can be efficiently elastically deformed toward the first rod-shaped member based on the clamping force of the clamp device.

[0010] In addition, in this invention, the connecting rod is configured to have a male thread portion and the axle pin is configured to have a female thread hole, and the connecting rod and the axle pin can be screwed together (fourth aspect). In this way, the tightening force of the clamp device can be adjusted by changing the screw-in position of the connecting rod and the axle pin.

[0011] In the present invention, an axially extending engagement groove can be provided on the outer peripheral surface of the first rod-shaped member, and an engagement protrusion that engages with the engagement groove can be provided on the clamp device (fourth aspect). In this way, unintended relative rotation between the first rod-shaped member and the second rod-shaped member can be prevented. [Brief description of the drawings]

[0012] [Figure 1] 1 is a side view of a wheelchair equipped with a footrest support mechanism according to one embodiment of the present invention; [Diagram 2] 2 is an enlarged view of the footrest support mechanism and its surroundings in FIG. 1. [Diagram 3] FIG. 3 is an exploded perspective view of the footrest support mechanism of FIG. 2. [Figure 4] FIG. 2 is a view showing the main body of the clamp device alone. [Diagram 5] 3 is a perspective view showing the clamp device of FIG. 2 from the bottom side. FIG. [Figure 6]In the cross-sectional view taken along the line VI-VI in FIG. 2, (A) shows the locked state, and (B) shows the unlocked state. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] 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 support mechanism 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.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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. In this embodiment, a footrest support mechanism 32 is provided that includes the footrest support rod 25, and the height of the footrest 26 is adjustable. The footrest support mechanism 32 will be described in detail below.

[0020] 2 is an enlarged view of the footrest support mechanism and its surroundings in FIG. 1, and FIG. 3 is an exploded perspective view of the footrest support mechanism in FIG. The footrest support rod 25 is composed of a first rod-shaped member 33 and a second rod-shaped member 37, and these rod-shaped members 33, 37 are made of metal pipes. The first rod-shaped member 33 constitutes the lower member of the footrest support rod 25, and the footrest 26 is attached to its lower end. Engagement grooves 34, 34 extending in the axial direction (longitudinal direction) are formed on the left and right side surfaces of the first rod-shaped member 33 (see FIG. 3, for example). The engagement grooves 34, 34 are formed at positions that do not face free ends of elastic deformation portions 40a, 40b of the second rod-shaped member 37, which will be described later (see FIG. 6, for example).

[0021] The second rod-shaped member 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 second rod-shaped member 37 has an inner diameter slightly larger than the outer diameter of the first rod-shaped member 33, so that the first rod-shaped member 33 can be slidably inserted into the second rod-shaped member 37.

[0022] 3, the lower end of the second rod-shaped member 37 is provided with a circumferential slit 38 extending in the circumferential direction at a position a predetermined distance above the lower end edge, and an axial slit 39 extending in the axial direction from the lower end edge to the circumferential slit 38, forming a pair of elastically deforming portions 40a and 40b that are elastically deformable in the plate thickness direction. These elastically deforming portions 40a, 40b are formed symmetrically with their free ends closely facing each other with the gap of the axial slit 39 in between.

[0023] A fixing piece 42 for fixing a clamp device 46, which is a component of the footrest support mechanism 32, to the second rod-shaped member 37 is provided immediately above the circumferential slit 38. A through hole 43 is formed in this fixing piece 42.

[0024] The clamp device 46 includes a main body portion 47 and a lever mechanism portion 61 . The main body 47 is a member attached to the second rod-shaped member 37, and is provided with an arc-shaped holding portion 48 that curves along the second rod-shaped member 37 and contains the elastically deforming portions 40a, 40b. As shown in FIG. 4, the holding portion 48 has an inner circumferential surface 49 that has approximately the same diameter as the outer diameter of the second rod-shaped member 37. 4(C), a pair of pressure-receiving pieces 51, 52 are provided facing each other with a gap therebetween in the holding portion 48. The pressure-receiving pieces 51 and 52 extend radially outward from the circumferential ends of the holding portion 48 and are provided at positions facing each other with a gap δ therebetween.

[0025] The pressure-receiving pieces 51, 52 receive an external force and deform the holding portion 48, and the outer surfaces 51a, 52a of the pressure-receiving pieces 51, 52 are receiving surfaces that receive a force from the lever mechanism portion 61. As shown in Fig. 4(C), the outer surface 51a is a curved surface, and the outer surface 52a is a flat surface. Further, the pair of pressure-receiving pieces 51, 52 are formed with an oval through hole 53 through which a connecting rod 70, which will be described later, is inserted.

[0026] A groove 55 capable of accommodating an operating portion 68 of a lever body 62 (described later) is formed along the circumferential direction on the outer surface of the holding portion 48 connected to the outer surfaces 51a, 52a of the pair of pressure-receiving pieces 51, 52. In addition, as shown in Figures 4(C) and 5, an engagement protrusion 56 is provided at the bottom of the holding portion 48, which protrudes inward from the inner surface 49 of the holding portion 48 and engages with the engagement groove 34 of the first rod-shaped member 33.

[0027] A pair of arm-shaped mounting pieces 58, 58 extend from the peripheral wall of the holding portion 48 on the side opposite the pressure-receiving pieces 51, 52, and a through hole 59 is formed at the tip of each of the mounting pieces 58, 58. The pair of mounting pieces 58, 58 sandwich the fixed piece 42 of the second rod-shaped member 37 shown in Fig. 3, and the clamp device 46 is attached and fixed to the second rod-shaped member 37 by a mounting bolt 45 inserted through the through holes 59, 59 and the through hole 43 of the fixed piece 42 and a nut (not shown). In this example, as shown in Figure 6, the clamp device 46 is attached to the second rod-shaped member 37 so that the gap δ between the pair of pressure-receiving pieces 51, 52 of the holding portion 48 overlaps with the gap (slit 39) between the pair of elastic deformation portions 40a, 40b of the second rod-shaped member 37.

[0028] The lever mechanism 61 includes a lever body 62, a pivot pin 64, and a connecting rod 70, and deforms the holding portion 48 in the radially reducing direction as the lever body 62 rotates. As shown in Fig. 3, the tip of the lever body 62 is bifurcated, and each of the bifurcated ... In this example, since the tip portion is formed in a bifurcated shape, the areas within the pressure-receiving piece 51 that are actually pressed by the pressing portion 66 are two areas: an area above the through hole 53 and an area below the through hole 53.

[0029] On the other hand, the portion extending from the tip of the lever body 62 to the opposite side to the pressing portion 66 is curved in an arc shape to form an operating portion 68 .

[0030] The connecting rod 70 is composed of a bolt having a rod-shaped shaft 71 with a male thread portion 71a formed thereon and a head portion 72 with a larger diameter than the shaft portion 71. As shown in Figures 6(A) and (B), the connecting rod 70 is disposed so as to pass through the through holes 53, 53 and straddle the pair of pressure-receiving pieces 51, 52. At the tip side of the connecting rod 70, the male thread portion 71a and the female thread hole 64a formed in the shaft pin 64 are screwed together. At the base end side of the connecting rod 70, the head portion 72 of the connecting rod 70 is disposed to face the outer surface 52a of the other pressure-receiving piece 52.

[0031] In the footrest support mechanism 32 thus configured, the state shown in Fig. 6(A), that is, the state where the region 66a of the pressing portion 66 with a large radial dimension faces the outer surface 51a of the pressure receiving piece 51, is the locked state. At this time, the clamping force of the lever mechanism portion 61 acts on the holding portion 48 in the direction (diameter contraction direction) of bringing the pair of pressure receiving pieces 51, 52 closer to each other as shown by the arrow in the figure, and the elastic deformation portions 40a, 40b of the second rod-shaped member 37 contained therein elastically deform radially inward and press the first rod-shaped member 33 located further inside. As a result, the footrest 26 of the wheelchair 10 is held at a desired position. In this locked state, the operating portion 68 of the lever body 62 is housed in the circumferential groove 55 of the clamp device 46.

[0032] 6(B), when the lever body 62 is rotated so that the area 66b of the pressing portion 66 with a small radial dimension faces the outer surface 51a of the pressure-receiving piece 51, this state is the unlocked state, in which no fastening force is applied to the holding portion 48 sufficient to elastically deform the elastic deformation portions 40a, 40b of the second rod-shaped member 37 radially inward, allowing the first rod-shaped member 33 to slide and allowing the height of the footrest 26 to be adjusted.

[0033] As described above, according to the footrest support mechanism 32 of this embodiment, by rotating a single type of lever body 62 without using tools, etc., it is possible to switch between a locked state in which the first rod-shaped member 33 is held in a desired position and an unlocked state in which the first rod-shaped member 33 is allowed to slide, and the height of the footrest 26 can be adjusted steplessly with a simple operation.

[0034] In addition, according to the footrest support mechanism 32 of this embodiment, a pair of elastic deformation portions 40a, 40b are provided with their free ends closely facing each other, and the clamp device 46 is attached so that the gap δ between the pair of pressure-receiving pieces 51, 52 overlaps with the gap 39 between the pair of elastic deformation portions 40a, 40b, and the pair of elastic deformation portions 40a, 40b can be efficiently elastically deformed toward the first rod-shaped member 33 based on the tightening force of the clamp device 46.

[0035] Furthermore, according to the footrest support mechanism 32 of this embodiment, the connecting rod 70 is configured to have a male threaded portion 71a, and the axle pin 64 is configured to have a female threaded hole 64a, and the connecting rod 70 and the axle pin 64 are screwed together, and the clamping force of the clamp device 46 can be adjusted by changing the screw-in position of the connecting rod 70 and the axle pin 64.

[0036] In addition, according to the footrest support mechanism 32 of this embodiment, an axially extending engagement groove 34 is provided on the outer peripheral surface of the first rod-shaped member 33, and an engagement protrusion 56 that engages with the engagement groove 34 is provided on the clamp device 46, thereby preventing unintended relative rotation between the first rod-shaped member 33 and the second rod-shaped member 37 in the locked and unlocked states.

[0037] Although the embodiments of the present invention have been described in detail above, these are merely examples. The present invention can be embodied in various modified forms without departing from the spirit and scope of the present invention. [Explanation of symbols]

[0038] 10. Wheelchair 25 Footrest support rod 26 Footrest 32 Footrest support mechanism 33 First rod-shaped member 34 Engagement groove 37 Second rod-shaped member 39 Axial slit (gap) 40a, 40b Elastic deformation portion 46 Clamping device 48 Wrapping part 51 Pressure receiving piece 52 Pressure receiving piece 52a Exterior 56 Engagement protrusion 61 Lever mechanism 62 Lever body 64 Axle Pins 64a Female thread hole 70 Connecting rod 71a Male thread δ Gap

Claims

1. a footrest support rod having a first rod-shaped member and a second rod-shaped member into which the first rod-shaped member is slidably inserted; a clamp device attached to the second rod-shaped member and configured to non-slidably hold the first rod-shaped member; A footrest support mechanism for a wheelchair, comprising: The second rod-shaped member has an elastic deformation portion that is elastically deformable in a plate thickness direction, The clamp device includes a holding portion that contains the elastic deformation portion, and a lever mechanism that deforms the holding portion in a diameter reducing direction in accordance with a rotation of a lever body, A footrest support mechanism that can be switched between a locked state in which the elastic deformation portion is pressed against the first rod-shaped member to hold the first rod-shaped member in a desired position, and an unlocked state in which the first rod-shaped member is allowed to slide, by rotating the lever body.

2. The holding portion has a pair of pressure-receiving pieces disposed opposite each other at a distance from each other at each end, The lever mechanism includes: a lever body having a pressing portion for pressing an outer surface of one of the pressure-receiving pieces; A shaft pin that rotatably supports the lever body; 2. The footrest support mechanism as described in claim 1, further comprising a connecting rod arranged across the pair of pressure-receiving pieces, one end of which is connected to the pivot pin and the other end of which faces the outer surface of the other pressure-receiving piece.

3. The elastic deformation portion is provided as a pair with free ends closely facing each other, 3. The footrest support mechanism according to claim 2, wherein the clamp device is attached so that a gap between the pair of pressure-receiving pieces and a gap between the pair of elastic deformation portions overlap each other.

4. 3. The footrest support mechanism according to claim 2, wherein said connecting rod has a male threaded portion, said pivot pin has a female threaded hole, and said connecting rod and pivot pin are screwed together.

5. A footrest support mechanism as described in any one of claims 1 to 4, wherein an axially extending engagement groove is provided on the outer peripheral surface of the first rod-shaped member, and an engagement protrusion that engages with the engagement groove is provided on the clamp device.

Images