JP3172909B2 - Wheelchair caster angle adjustment structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for adjusting a caster angle of a front wheel composed of caster wheels in a wheelchair.

[0002]

2. Description of the Related Art Conventionally, a front wheel of a wheelchair is formed of a caster wheel, and an axle is supported by a fork extending obliquely. Is fixed, and the caster shaft is rotatably held at the front portion of the frame via a bearing or the like.

[0003] In a conventional wheelchair, if the outer diameter of the front wheel is increased according to the user's physique or preference, for example, in order to lower the seat surface backward, the front portion of the frame rises, , The caster angle (the angle between the axial direction of the caster shaft and the vertical direction) changes from 0 ° to several °.

[0004] If the caster angle deviates from the vertical direction in this way, it prevents the front wheels from freely rotating 360 °, making it difficult to change the direction of the wheelchair, which is not preferable.

Therefore, in a conventional wheelchair, Japanese Patent Laid-Open No. 9-2
As described in Japanese Patent No. 20261, adjustment was performed using two adjustment pipes. Each of these two adjusting pipes is configured such that the through hole on the inner peripheral side crosses the axial direction of the through-hole on the outer peripheral surface of the adjusting pipe.

[0006] The mode of use of these adjusting pipes is as follows.
With the bearing interposed, the inner peripheral adjustment pipe is externally mounted on the caster shaft, the outer peripheral adjustment pipe is externally mounted, and the outer peripheral adjustment pipe is fixed to the front side of the frame. The caster shaft was adjusted in the vertical direction so that the caster angle was 0 ° by appropriately rotating the inner and outer adjustment pipes.

However, the conventional structure requires two adjusting pipes, and further requires a means for fixing the inner circumferential adjusting pipe to the outer circumferential adjusting pipe, thus increasing the number of components.

Further, in the conventional structure, the adjusting pipe on the outer peripheral side is fixed to the front frame of the wheelchair, and is fixed to the head pipe arranged vertically in the axial direction. It was not possible to directly connect the caster wheels to the base pipe arranged in the vehicle.
By the way, if the caster shaft can be directly connected to the base pipe, the position of the caster shaft can be easily adjusted in the front-rear direction along the axial direction of the base pipe, which is convenient.

The present invention has been made to solve the above-mentioned problem, and can reduce the number of parts and directly connect a caster wheel to a base pipe disposed in the front-rear direction below a wheelchair. The caster angle adjustment structure of a wheelchair that can easily adjust the direction of the caster shaft in the vertical direction even if the angle of the base pipe from the horizontal direction is changed by changing the height position, outer diameter, etc. The purpose is to provide.

[0010]

According to the caster angle adjusting structure of the present invention, a caster shaft is fixed to an upper portion of a fork for supporting a front wheel, and the caster shaft is rotatably held by a bearing. Is mounted on a base pipe disposed in the front-rear direction of the lower part of the wheelchair, and is a structure for adjusting a caster angle of a wheelchair in which an axial direction of the caster shaft can be adjusted, wherein the clamp comprises the bearing On the inner periphery of the holding hole for holding the caster shaft with
Along with disposing a substantially cylindrical sleeve so that it can be fixed,
It has an insertion hole through which the base pipe is inserted, and is attached to the base pipe so that the circumferential arrangement position can be adjusted, and the sleeve has a fitting hole into which the bearing on the inner peripheral side is fitted. The axial direction of the fitting hole intersects the axial direction of the outer peripheral surface of the sleeve held in the holding hole.

[0011] The clamp includes a main body that forms a part of the inner peripheral surface of the holding hole and the inner peripheral surface of the insertion hole between the holding hole and the insertion hole, and one side of the main body. A sleeve side portion that is disposed on the other side of the inner peripheral surface of the holding hole, and a pipe side portion that is disposed on the other side of the main body portion and that forms the remaining inner peripheral surface of the insertion hole. The main body, the sleeve side, and the pipe side, there is provided an assembling hole having a screw hole at the part of the main body, the sleeve side and the sleeve side The holding hole and the insertion hole may be configured to be reduced in diameter by bolts that are inserted into and screwed into the mounting holes from both sides of the pipe side.

[0012]

According to the caster angle adjusting structure of the present invention, the sleeve is provided between the inner peripheral surface of the holding hole of the clamp fixed to the base pipe and the bearing rotatably supporting the caster shaft. The sleeve has a substantially cylindrical shape, and the axial direction of the fitting hole on the inner peripheral side for fitting the bearing intersects the axial direction of the outer peripheral surface.

Therefore, when the height position and the outer diameter of the caster wheel are changed to change the angle of the base pipe in the axial direction from the horizontal direction, the sleeve held by the holding hole of the clamp is fixed to a predetermined position. The caster shaft can be easily adjusted in the vertical direction if the clamp itself is rotated and fixed at a predetermined angle in the circumferential direction of the base pipe while being fixed by being rotated by an angle.

Then, a simple structural part of a sleeve having a predetermined shape and a clamp capable of fixing the sleeve and assembling to the base pipe is used, and thereafter, a general-purpose caster shaft or fork is used. Thus, the caster wheel can be directly connected to the base pipe.

Therefore, in the caster angle adjusting structure according to the present invention, the caster wheel can be directly connected to the base pipe arranged in the front-rear direction below the wheelchair with a small number of parts, and the caster wheel can be connected directly. Even if the angle of the base pipe in the axial direction from the horizontal direction is changed by changing the height position, the outer diameter, or the like, the direction of the caster shaft can be easily adjusted in the vertical direction.

The clamp is disposed on one side of the main body, the main body constituting a part of the inner peripheral surface of the holding hole and the inner peripheral surface of the insertion hole between the holding hole and the insertion hole. A sleeve side portion that forms the remaining portion of the inner peripheral surface of the holding hole, and a pipe side portion that is disposed on the other side of the main body portion and that forms the remaining portion of the inner peripheral surface of the insertion hole. , A sleeve side portion, and a pipe side portion, an assembling hole having a screw hole in the main body portion is provided, and the sleeve side portion and the pipe side portion are inserted from both sides and screwed together. In the case where the diameter of the holding hole and the insertion hole is reduced by using the bolt, the following operation and effect can be obtained.

That is, by inserting the bolt into the mounting hole and screwing it into the screw hole from both sides of the sleeve side and the pipe side, the diameter of the holding hole and the diameter of the insertion hole can be reduced. Therefore, for example, first, the sleeve is rotated by a predetermined angle, and the sleeve is fixed to the clamp by tightening a bolt inserted from the side of the sleeve, and then the clamp itself is rotated by a predetermined angle around the base pipe, The clamp can be fixed to the base pipe by tightening the bolt inserted from the pipe side, and the caster shaft can be easily adjusted in the vertical direction by the operation of tightening or loosening the two types of bolts.

Further, the clamp is simply provided with an assembling hole having a screw hole, and a predetermined bolt is inserted from both sides of the assembling hole, so that the number of parts increases and the assembling hole is increased. Can be suppressed as much as possible, and the configuration can be simplified.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings.

As shown in FIG. 1, the wheelchair C of the embodiment is provided with a base pipe 2 arranged in the front-rear direction at a lower portion on both left and right sides of a frame 1. A front wheel 42 as a caster wheel is attached to each of the left and right base pipes 2 using a clamp 7 or the like. The rear wheel 5 is attached to each of the back pipes 3 arranged on the right and left rear portions of the wheelchair C using the axle attachment bracket 4. The seats are arranged between the seat pipes 6 arranged on the left and right sides of the wheelchair C.

As shown in FIGS. 1 and 4, the front wheel 42 is rotatably supported by disposing a bearing such as a ball bearing (not shown) on a horizontally disposed axle 43. The fork 41 is supported by a fork 41. In the fork 41, a plurality of arrangement holes 41a for disposing the axle 43 are arranged vertically displaced so that the height of the front wheels 42 can be adjusted and the inclination of the seat can be adjusted.

As shown in FIGS. 2 to 4, a caster shaft 34 extending upward is fixed to a top of the fork 41 with a nut 39 fixed thereto. The caster shaft 34 has a cylindrical shaft portion 35, a hexagonal plate-shaped nut portion 36 disposed below the shaft portion 35, and a bolt portion 37 disposed below the nut portion 36 and screwed with the nut 39. And is provided. The shaft portion 35 is provided with a screw hole 35a opening at the upper end.

A substantially cylindrical sleeve 23 is disposed around the caster shaft 34 with two bearings 29 and 30 formed of a ball bearing or the like interposed therebetween. Outer cases 29a and 30a of these bearings 29 and 30 (see FIG. 4)
Are the upper and lower large diameter portions 2 in the fitting hole 27 of the sleeve 23.
7a and 27c are fixed by interference fit. Further, the upper bearing 29 has an inner case 29b which is externally mounted on a holding bolt 32 screwed into a screw hole 35a of the shaft portion 35, and is pressed against the upper end surface of the shaft portion 35 by the bolt 32. Further, the lower bearing 30 is
0b is provided on the outer periphery of the lower portion of the shaft portion 35. The caster shaft 34 is rotatable with respect to the sleeve 23 by the bearings 29 and 30.

The sleeve 23 is formed in a substantially cylindrical shape having flanges 25 and 26 on the upper and lower sides of the main body 24 as shown in FIGS. Hole 2 for fitting bearings 29 and 30 together
7 is provided. The fitting hole 27 is
The large diameter portions 27a and 27c for fitting the respective 30 with each other and a small diameter portion 27b between the large diameter portions 27a and 27c are provided.

The axial direction X2 of the fitting hole 27 is
The outer circumferential surface of the sleeve main body 24 intersects with the axial direction X1. In the case of the embodiment, the intersection angle α between the axial directions X1 and X2 is 5 °.

Reference numeral 27d denotes a wide-open portion into which a cap 21 for closing the fitting hole 27 is fitted.
Is the axial direction X1 of the outer peripheral surface of the sleeve body 24.
Matches. An O-ring 22 is provided on the cap 21. 26a is a sleeve 23
This is a flat portion provided on the flange portion 26 for gripping when rotating.

As shown in FIGS. 2 to 6, the clamp 7 for holding the sleeve 23 has a holding hole 11 for holding the main body 24 and the upper flange 25 of the sleeve 23. It is provided with an insertion hole 12 that can be assembled to the base pipe 2 at right angles. This clamp 7
Is a holding hole 11 between the holding hole 11 and the insertion hole 12.
And a main body portion 8 that forms a part of the inner peripheral surface of the main body portion and the inner peripheral surface of the insertion hole 12.
Sleeve side portion 9 constituting the remaining portion of the inner peripheral surface of the main body portion 8
, And a pipe side portion 10 that forms the remaining portion of the inner peripheral surface of the insertion hole 12. Further, the clamp 7 is formed with four assembly holes 13 penetrating the main body 8, the sleeve side 9, and the pipe side 10. Each of these assembling holes 13 is configured such that a portion of the main body 8 is formed as a screw hole 16, and a hole 14 of the sleeve side portion 9 and a hole 15 of the pipe side portion 10 are respectively formed with the large diameter portions 14 a. And small diameter portions 14b and 15b.

Then, the clamp 7 is inserted into the assembling hole 13 from both sides of the sleeve side 9 and the pipe side 10 by four bolts 18 and 19, respectively.
The holding hole 11 and the insertion hole 12 are configured to be reduced in diameter.

If the diameter of the holding hole 11 is reduced, the sleeve 23 can be fixed to the clamp 7.
By reducing the diameter of 2, the clamp 7 can be fixed to the base pipe 2. Further, when the bolts 18 and 19 are tightened, their heads are housed in the large diameter portions 14a and 15a of the assembling hole 13, so that interference between the heads and surrounding members is minimized. It is configured to:

In the wheelchair C of this embodiment, when adjusting the angle of the seat, the height of the axle 43 supporting the front wheel 42 is adjusted, that is, the arrangement position of the axle 43 is adjusted to the position of the fork 41. Is performed by changing to the arrangement hole 41a.
Of course, the outer diameter of the front wheel 42 can be changed,
Back pipe 3 of axle mounting bracket 4 supporting
May be adjusted.

At the time of this adjustment, for example, when the axial direction Y of the base pipe 2 is to be parallel to the horizontal direction H, first, each bolt 18 is loosened, and the diameter of the holding hole 11 is increased.
Then, the sleeve 23 is rotated in a predetermined direction, and as shown in FIG.
2 so that they face up and down, and then each bolt 18
Tighten. At this time, the caster shaft 34 is merely oriented in the vertical direction when viewed from the side.
Not suitable for

Therefore, each bolt 19 is loosened, and the diameter of the insertion hole 12 is increased. Then, the clamp 7 is rotated by a predetermined angle in the circumferential direction of the base pipe 2 so that the axial direction X2 of the caster shaft 34 is oriented in the vertical direction V as shown in FIG.
Each bolt 19 may be tightened.

With this adjustment, the axial direction X2 of the caster shaft 34 becomes the vertical direction V, so that the front wheel 42 can rotate 360 ° about the caster shaft 34 without any trouble, and the direction of the wheelchair C Does not hinder conversion.

Therefore, in the caster angle adjusting structure of the embodiment, even if the angle of the base pipe 2 in the axial direction Y from the horizontal direction H is changed by changing the height position, the outer diameter and the like of the caster wheel 42, The direction of the caster shaft 34 can be easily adjusted in the vertical direction by the turning operation of the sleeve 23 with respect to the clamp 7 and the turning operation of the clamp 7 with respect to the base pipe 2 together with the tightening and loosening operations of the clamps 18 and 19. .

In the embodiment, a simple structural part of a sleeve 23 having a predetermined shape and a clamp 7 which can fix the sleeve 23 and can be assembled to the base pipe 2 is used. Caster shaft 34 and fork 41
The caster wheel 42 can be connected to the base pipe 2 only by using the caster wheel 42 with a small number of parts.
Can be directly connected.

Further, in the embodiment, the clamp 7 is provided with the main body 8 which forms a part of the inner peripheral surface of the holding hole 11 and the inner peripheral surface of the insertion hole 12 between the holding hole 11 and the insertion hole 12.
And a sleeve side portion 9 forming the remaining portion of the inner peripheral surface of the main holding hole 11 and a pipe side portion 10 forming the remaining portion of the inner peripheral surface of the insertion hole 12. Part 9 and the pipe side part 10
Is provided with an assembling hole 13 having a threaded hole 16 at the portion, and the holding holes 11 are inserted by bolts 18 and 19 which are inserted from both sides of the sleeve side portion 9 and the pipe side portion 10 and screwed.
And the insertion hole 12 are configured to be reduced in diameter.

Therefore, the sleeve side 9 and the pipe side 1
Bolts 18 and 19 from both sides of the mounting hole 1
3 and screwed into the screw hole 16, the diameter of each of the holding hole 11 and the insertion hole 12 can be reduced. For example, first, the bolt 18 inserted from the sleeve side 9 is loosened and the sleeve 18 is loosened. The sleeve 23 is fixed to the clamp 7 by rotating the bolt 23 by a predetermined angle and tightening the bolt 18.
Loosen the bolt 19 inserted from 0 and clamp 7
The clamp 7 can be fixed to the base pipe 2 by rotating itself by a predetermined angle around the base pipe 2 and tightening the bolt 19.
The caster shaft 34 can be easily adjusted in the vertical direction by the two-stage turning operation of the sleeve 23 and the clamp 7 together with the tightening and loosening operations of each of the 19. Incidentally, the two-stage turning operation of the sleeve 23 and the clamp 7 may be performed simultaneously or one of them may be performed first.

Further, the clamp 7 of the embodiment has a structure in which the assembling hole 13 having the screw hole 16 is simply provided, and predetermined bolts 18 and 19 are inserted from both sides of the assembling hole 13. In addition, an increase in the number of parts and an increase in the number of mounting holes 13 can be suppressed as much as possible, and the configuration can be simplified.

In the clamp 7 of the embodiment, the screw hole 16 is provided in the assembling hole 13.
The holding hole 11 and the insertion hole 12 are formed by using bolts and nuts so as to connect the sleeve side portion 9, the main body portion 8, and the pipe side portion 10 without using the mounting hole 13 as a simple through hole. The diameter may be reduced. Incidentally, when one bolt is inserted into the mounting hole 13 in this way, the diameter of the holding hole 11 and the insertion hole 12 can be reduced at the same time.

Further, in the clamp 7 according to the embodiment, the main body 8, the sleeve side 9, and the pipe side 10 are completely separated.
Although the three parts are shown, the sleeve side part 9 and the pipe side part 10 are not completely separated from the main body part 8 without completely separating the outer peripheral surface of each of the holding hole 11 and the insertion hole 12. Each holding slit 11
Alternatively, the clamp 7 may be formed from an integral body in which the diameter of the insertion hole 12 can be reduced.

Furthermore, in the embodiment, the sleeve 23
The case where the intersection angle α between the axial direction X2 of the fitting hole 27 and the axial direction X1 of the outer peripheral surface of the sleeve main body 24 held in the holding hole 11 is 5 ° is shown, and this intersection angle α is 5 °.
The angle is not limited to 5 ° and may be more than 5 ° or less than 5 °. In addition, if the intersection angle α is increased, even if the axial direction Y of the base pipe 2 is largely changed, it can be easily dealt with.

[Brief description of the drawings]

FIG. 1 is a schematic side view of a wheelchair according to an embodiment of the present invention.

FIG. 2 is an enlarged side view of the vicinity of a clamp according to the embodiment.

FIG. 3 is an enlarged front view of the vicinity of the clamp according to the embodiment.

FIG. 4 is an exploded side view of the vicinity of a front wheel according to the embodiment.

FIG. 5 is a plan view of the clamp according to the embodiment.

FIG. 6 is a front view of the clamp.

FIG. 7 is a plan view of the sleeve of the embodiment.

FIG. 8 is a front view of the sleeve.

FIG. 9 is a bottom view of the sleeve.

FIG. 10 is a side view when the caster shaft of the embodiment is adjusted.

FIG. 11 is a front view when the caster shaft of the embodiment is adjusted.

[Explanation of symbols]

 2 ... base pipe, 7 ... clamp, 8 ... body, 9 ... sleeve side, 10 ... pipe side, 11 ... holding hole, 12 ... insertion hole, 13 ... assembly hole, 16 ... screw hole, 18/19 ... Bolt, 23 ... Sleeve, 27 ... Fit hole, 34 ... Caster shaft, 41 ... Fork, 42 ... (Caster wheel) Front wheel, X1 ... (outer peripheral surface of sleeve body) axial direction, X2 ... (Sleeve fitting hole) ) Axial direction, Y: (base pipe) axial direction, V: vertical direction, H: horizontal direction, C: wheelchair.

Claims (2)

(57) [Claims] A caster shaft is fixed to an upper portion of a fork supporting a front wheel, and a clamp for rotatably holding the caster shaft via a bearing is provided on a base pipe disposed in a front-rear direction below a wheelchair. A caster angle adjustment structure for a wheelchair, which is configured to be assembled and is capable of adjusting an axial direction of the caster shaft, wherein the clamp is provided on an inner periphery of a holding hole that holds the caster shaft with the bearing interposed. A substantially cylindrical sleeve is provided so as to be fixable, and an insertion hole through which the base pipe is inserted is attached to the base pipe so that a circumferential arrangement position can be adjusted. A fitting hole for fitting the bearing on the peripheral side is provided, and an axial direction of the fitting hole intersects an axial direction of an outer peripheral surface of the sleeve held by the holding hole. Adjust the structure of the wheelchair of the caster angle that. 2. The main body, wherein the clamp forms a part of the inner peripheral surface of the holding hole and the inner peripheral surface of the insertion hole between the holding hole and the insertion hole, and one of the main body portions And a pipe side disposed on the other side and constituting the remaining portion of the inner peripheral surface of the holding hole, and a pipe side disposed on the other side of the main body and constituting the remaining portion of the inner peripheral surface of the insertion hole. And an assembly hole that penetrates the main body portion, the sleeve side portion, and the pipe side portion and has a portion of the main body portion as a screw hole is provided. The caster angle of the wheelchair according to claim 1, wherein the holding hole and the insertion hole are reduced in diameter by bolts that are inserted into and screwed into the mounting holes from both sides of the pipe side. Adjustment structure.