Wheel retention unit, wheel unit equipped therewith, and walker

Abstract

To provide a wheel detachment preventing unit that is used with a walking car involving frequent replacement of wheels and can reduce the possibility that a wheel comes off due to loosening or not being completely fitted to an axle.SOLUTION: A wheel detachment preventing unit 100 includes: an axle insertion hole 120 into which an axle 12 can be inserted; a notch 122 communicating with the axle insertion hole 120; a pair of axle groove slide-fitting parts 124 facing the notch 122 and arranged opposite each other at an interval that allows slide-fitting into the axle groove 20 of the axle 12; and an axle insertion hole filling part 138 to be fitted in the axle insertion hole 120 with the axle 12 lying in the notch 122 and the axle groove 20 fitted in the axle groove sliding fitting parts 124.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a wheel retaining unit used for a walking aid for the elderly and others who have difficulty walking independently, a wheel unit including the same, and a walking aid.

Background Art

[0002] Conventionally, a retaining ring (also called an "E clip", "C clip", etc.) has been used to prevent the wheel from coming off the axle (for example, the retaining ring 6 in Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, with conventional retaining rings, there is a risk that they may loosen and fall off after being used for a certain period of time, or may fall off similarly because they do not fit properly into the axle.

[0005] By the way, for walking aids used by the elderly and others who have difficulty walking independently, of course, strong safety is required so that the wheels do not accidentally fall off during use. On the other hand, there is a special situation that rental rather than purchase is mostly selected. For this reason, inevitably, since one walking aid is used by various users for a long period of time, the frequency of wheel replacement increases, and there has been a concern that the possibility of the above-mentioned falling off increases. Therefore, it has been difficult to come up with the idea of adopting a retaining ring or the like, and means such as threading the axle and fixing it with a nut, which are relatively firmly fastened, have been adopted. On the other hand, since such a firmly fastening means is adopted, there is a problem that it takes unnecessary time and effort during maintenance and wheel replacement.

[0006] The present invention has been made in view of the above circumstances, and its purpose is to provide a wheel retention unit, a wheel unit equipped with the same, and a walker, which can be used in walkers where the wheels are frequently replaced, and which can be easily replaced and reduce the possibility of the wheel becoming loose and falling off during use or falling off because it is not properly seated on the axle. [Means for solving the problem]

[0007] According to one aspect of the present invention, A wheel retention unit for preventing wheels used in walking aids from coming off the axle, The axle has axle grooves formed in a direction perpendicular to the longitudinal direction. The axle insertion hole through which the axle can be inserted, A notch communicating with the axle insertion hole, A pair of axle groove sliding fitting portions facing each other and spaced apart so as to be able to slide into the axle groove, The axle is located in the notch, and the axle groove is fitted into the axle groove sliding fitting portion, and the axle insertion hole filling portion is fitted into the axle insertion hole. A wheel retention unit is provided.

[0008] Preferably, On the side of the axle insertion hole filling portion facing the notch, a biasing surface is formed that pushes the axle toward the back of the notch when the axle insertion hole filling portion is fitted into the axle insertion hole.

[0009] Preferably, It comprises the axle insertion hole, the axle groove sliding fitting portion, and the main body portion having the notch, The main body is, The axle insertion hole, the axle groove sliding fitting portion, and the plate-shaped portion with the notch formed therein, The plate-like portion has a retaining portion on its outer side that is thicker than the plate-like portion.

[0010] Preferably, The axle insertion hole, the axle groove sliding fitting portion, and the main body portion having the notch, It has the axle insertion hole filling portion and a lid portion that is rotatably attached to the main body portion, By rotating the lid portion relative to the main body portion, the axle insertion hole filling portion can be inserted into and removed from the axle insertion hole.

[0011] According to another aspect of the present invention, The aforementioned An axle in which the axle groove is formed in a direction perpendicular to the longitudinal direction, A wheel attached to the axle, It includes the wheel retention unit described above. A wheel unit for a walking aid is provided.

[0012] According to another aspect of the present invention, A walking aid equipped with the aforementioned wheel unit is provided. [Effects of the Invention]

[0013] According to the wheel retention unit of the present invention, after inserting the axle into the axle insertion hole, the wheel retention unit can be attached to the axle by sliding the axle groove fitting portion into the axle groove formed in the axle, and then moving the axle into a notch communicating with the axle insertion hole.

[0014] With the axle in the notch and the axle groove fitted into the axle groove sliding fitting portion, the axle insertion hole filling portion is fitted into the axle insertion hole. As a result, the axle is prevented from moving from the notch to the axle insertion hole by the axle insertion hole filling portion, thus preventing the axle retention unit from loosening and falling out during use.

[0015] In addition, if the axle has not fully moved into the notch, the axle will obstruct the insertion hole filling portion from being fitted into the axle insertion hole. This prevents the axle retention unit from not being properly fitted to the axle, thus preventing the axle retention unit from falling out.

Brief Description of the Drawings

[0016] [Figure 1] It is an exploded perspective view showing an example of a wheel unit 10 to which the present invention is applied. [Figure 2] It is a perspective view showing an example of a wheel removal and stop unit 100 to which the present invention is applied. [Figure 3] It is a perspective view showing an example of a wheel removal and stop unit 100 to which the present invention is applied. [Figure 4] It is a perspective view showing an example of a wheel removal and stop unit 100 to which the present invention is applied. [Figure 5] It is a cross-sectional view showing an example of a wheel removal and stop unit 100 to which the present invention is applied. [Figure 6] It is a perspective view showing an example of a cover 16. [Figure 7] It is a perspective view showing the assembled state of the wheel unit 10. [Figure 8] It is a perspective view showing the state where the cover 16 is removed from the state of FIG. 7. [Figure 9] It is a diagram showing the procedure for attaching the wheel removal and stop unit 100 to the axle 12. [Figure 10] It is a diagram showing the procedure for attaching the wheel removal and stop unit 100 to the axle 12. [Figure 11] It is an exploded perspective view showing the wheel unit 10 according to Modification 1. [Figure 12] In the wheel unit 10 according to Modification 1, it is a diagram showing the procedure for attaching the wheel removal and stop unit 100 to the axle 12. [Figure 13] In the wheel unit 10 according to Modification 1, it is a diagram showing the procedure for attaching the wheel removal and stop unit 100 to the axle 12. [Figure 14] In the wheel unit 10 according to Modification 1, it is a diagram showing the procedure for attaching the wheel removal and stop unit 100 to the axle 12. n

Modes for Carrying Out the Invention

[0017] (Regarding the configuration of the wheel unit 10) One embodiment of a wheel unit 10 to which the present invention is applied will be described. As shown in Figure 1, the wheel unit 10 generally comprises an axle 12, a wheel 14, a wheel retention unit 100, and a cover 16.

[0018] The axle 12 is a cylindrical member that protrudes horizontally from the lower end of the leg frame B of the walker A, and has an axle groove 20 formed in a direction perpendicular to the longitudinal direction.

[0019] In this embodiment, a pair of axle grooves 20 are formed facing each other at the tip of the axle 12. The axle groove 20 may be formed as a single groove extending around the circumference, or as a single groove not extending around the circumference. Furthermore, the position on the axle 12 where the axle groove 20 is formed is not particularly limited.

[0020] The wheel 14 has an axle hole 22 through which the axle 12 is inserted. In this embodiment, a circular recess 24 is formed on the side of the wheel 14 opposite to the side facing the leg frame B, with the axle hole 22 as the center. With the wheel retention unit 100 housed in this recess 24, the cover 16 is placed over the recess 24 from the outside.

[0021] The wheel retention unit 100 has the role of preventing the wheel 14 from coming off the axle 12, and as shown in Figures 2 to 4, it generally comprises a main body 102 and a cover 104.

[0022] The main body portion 102 generally consists of a plate-shaped portion 110 and a holding portion 112.

[0023] The plate-like portion 110 is made of a metal such as iron or aluminum, and has an axle insertion hole 120, a notch 122, and a pair of axle groove sliding fitting portions 124.

[0024] The axle insertion hole 120 is a hole formed to a size that allows the axle 12 to be inserted (i.e., a hole formed to be larger than the diameter of the axle 12). In this embodiment, the axle insertion hole 120 is formed by combining a rectangular hole and a semicircular hole, but the shape of the axle insertion hole 120 is not limited to this, and for example, it may be a circular hole.

[0025] The notch 122 is formed in a position that communicates with the axle insertion hole 120, allowing the axle 12, which is inserted through the axle insertion hole 120, to move through the notch 122 while remaining inserted.

[0026] The pair of axle groove sliding fitting portions 124 are positioned opposite each other, facing the notch 122, and are spaced apart so that they can slide into the pair of axle grooves 20 formed in the axle 12.

[0027] If the axle groove 20 formed on the axle 12 is a single groove that does not extend around the circumference, one axle groove sliding fitting portion 124 will be slidably fitted against the axle groove 20, and the other axle groove sliding fitting portion 124 will be brought into contact with the circumferential surface of the axle 12 at a position opposite the axle groove 20. If there is a single groove that extends around the circumference, one axle groove sliding fitting portion 124 will be slidably fitted against the axle groove 20.

[0028] The retaining portion 112 is a part formed on the outside of the plate-shaped portion 110 described above, and is thicker than the plate-shaped portion 110. By forming the retaining portion 112 thicker than the plate-shaped portion 110 in this way, the wheel retention unit 100 can be attached to and detached from the axle 12 without using any tools.

[0029] In this embodiment, a pair of retaining recesses 126 are formed on both sides of the notch 122 on the periphery of the retaining portion 112, and the user moves the wheel retention unit 100 by placing their fingers on these retaining recesses 126. In addition, a lid fitting recess 128 into which the lid portion 104 fits is formed in the center of the retaining portion 112, and the axle insertion hole 120, notch 122, and a pair of axle groove sliding fitting portions 124 of the plate-shaped portion 110 are exposed at the bottom of this lid fitting recess 128.

[0030] Furthermore, a sliding projection 129 is provided on the surface of the holding portion 112 opposite to the surface where the lid fitting recess 128 is formed (the surface facing the recess 24 of the wheel 14). When the wheel retention unit 100 is attached to the axle 12 or when the wheel 14 rotates, only the tip surface of this sliding projection 129 contacts and slides against the bottom surface of the recess 24 of the wheel 14. This results in less friction compared to when the entire surface of the holding portion 112 facing the recess 24 contacts and slides against the bottom surface of the recess 24, making the wheel retention unit 100 less likely to hinder the smooth rotation of the wheel 14, which is advantageous.

[0031] In this embodiment, the holding portion 112 is a resin member that is insert-molded to enclose the plate-shaped portion 110, but it is not limited to this.

[0032] The lid portion 104 is a member that is rotatably attached to the main body portion 102, and has a lid body 134, an engaging portion 136, and an axle insertion hole filling portion 138.

[0033] More specifically, the lid portion 104 is made rotatable by fitting a pair of pivot holes 130 formed at the outer end of the lid portion fitting recess 128 of the main body portion 102 (holding portion 112) into the pivot shafts 132 that protrude from one end of the lid portion body 134 on both sides.

[0034] The engaging portion 136 protrudes from the other end of the lid body 134, and when the lid 104 is rotated relative to the body 102 and the lid 104 is fitted into the lid fitting recess 128, it engages with the engaging recess 140 formed on the end of the lid fitting recess 128 of the body 102 (holding portion 112) opposite to the end where the rotation hole 130 is formed. This prevents the lid 104, which is fitted into the lid fitting recess 128, from unintentionally separating from the body 102.

[0035] The axle insertion hole filling portion 138 is a component that is fitted into the axle insertion hole 120 when the axle 12 is in the notch 122 of the main body portion 102 and the axle groove 20 is fitted into the axle groove sliding fitting portion 124. It is provided protruding adjacent to the engaging portion 136 on the lid body 134, closer to the inside (closer to one end of the lid body 134). Adjacent includes cases where it is continuous with the engaging portion 136, and cases where it is adjacent to the engaging portion 136 at a predetermined distance.

[0036] As a result, as shown in Figure 5, the axle insertion hole filling portion 138 can be inserted into and removed from the axle insertion hole 120 by rotating the lid portion 104 relative to the main body portion 102.

[0037] Furthermore, on the side of the axle insertion hole filling portion 138 facing the notch 122, a biasing surface 142 is formed that biases the axle 12 toward the back of the notch 122 when the axle insertion hole filling portion 138 is fitted into the axle insertion hole 120.

[0038] The axle insertion hole filling portion 138 may be formed separately from the main body portion 102 and the cover portion 104.

[0039] As shown in Figures 1 and 6, the cover 16 is a component that is placed over the wheel retaining unit 100 when it is housed in the recess 24 of the wheel 14, covering the recess 24. The cover has a cover body 144, a fitting projection 146, an inspection hole 148, a notch 150, and an engaging projection 152.

[0040] By attaching the cover 16 to the wheel 14, even if the lid 104 of the wheel retention unit 100 is damaged or the engagement of the lid 104 with the main body 102 is not successful, it is possible to prevent the wheel retention unit 100 from moving undesirably and coming off the axle 12.

[0041] The cover body 144 is a roughly disc-shaped component.

[0042] The fitting projection 146 is a portion that protrudes from the surface of the cover body 144 facing the wheel 14, and is designed to fit into the recess 24 of the wheel 14. In this embodiment, the fitting projection 146 has a cross-sectional shape consisting of a ring-shaped portion and four straight portions that extend radially outward from the ring-shaped portion. The shape of the fitting projection 146 is not limited to this, as long as it can fit into the recess 24.

[0043] The inspection hole 148 is a through-hole formed in the center of the cover body 144, allowing the wheel retention unit 100 housed in the recess 24 to be visually inspected when the cover 16 is attached to the wheel 14. This ensures that even if the wheel retention unit 100 is not attached to the axle 12 when the cover 16 is attached to the wheel 14, the absence of the wheel retention unit 100 can be confirmed through the inspection hole 148.

[0044] Two notches 150 are formed symmetrically from the center of the cover body 144. The presence of these notches 150 creates thin-walled sections 154 on the outside of the notches 150. When the user presses these thin-walled sections 154 toward the center of the cover body 144, the thin-walled sections 154 flex in the same direction.

[0045] The engaging projection 152 is a portion of the pair of thin-walled portions 154 described above that protrudes from the surface facing the wheel 14, and is designed to engage with the engaging recess 156 formed on the surface of the wheel 14.

[0046] The cover 16 is fixed to the wheel 14 by inserting the fitting projection 146 into the recess 24 formed in the wheel 14 and engaging the engaging projection 152 with the engaging recess 156. When removing the cover 16 from the wheel 14, the thin-walled portion 154 of the cover body 144 is pressed toward the center of the cover body 144 (see Figure 7), causing the thin-walled portion 154 to bend in the same direction, releasing the engagement of the engaging projection 152 with the engaging recess 156. By pulling the cover 16 while maintaining the bent state, the cover 16 can be removed from the wheel 14 (see Figure 8).

[0047] (Features of the wheel retention unit 100) According to the wheel retention unit 100 of this embodiment, after inserting the axle 12 into the axle insertion hole 120 (see Figure 9), the wheel retention unit 100 can be attached to the axle 12 by sliding the axle groove fitting portion 124 into the axle groove 20 formed in the axle 12 and moving the axle 12 into the notch 122 that communicates with the axle insertion hole 120 (see Figure 10).

[0048] In addition, if the axle 12 has not fully moved into the notch 122, even if the lid 104 is to be rotated relative to the main body 102, the axle 12 will get in the way, preventing the axle insertion hole filling part 138 from being fitted into the axle insertion hole 120. This prevents the wheel retention unit 100 from not being properly fitted to the axle 12, thus preventing the wheel retention unit 100 from falling out.

[0049] Furthermore, on the side of the axle insertion hole filling portion 138 facing the notch 122, a biasing surface 142 is formed that pushes the axle 12 toward the back of the notch 122 when the axle insertion hole filling portion 138 is fitted into the axle insertion hole 120. Therefore, if the axle 12 is slightly protruding from the notch 122, rotating the lid portion 104 relative to the main body portion 102 to bring the axle insertion hole filling portion 138 closer to the axle insertion hole 120 will cause the biasing surface 142 to push the axle 12 toward the back of the notch 122, thereby completely moving the axle 12 into the notch 122. This makes it possible to more reliably avoid a situation where the wheel retention unit 100 is not properly fitted to the axle 12.

[0050] (Variation 1) In the embodiment described above, the cover 16 was attached to the wheel 14 by placing it over the wheel retention unit 100, thus providing a double layer of protection against the wheel retention unit 100 coming off. However, instead of the cover 16, a wheel retention unit clip 202 may be formed on the side of the caster fork 200 to which the wheel 14 is rotatably mounted, as shown in Figure 11.

[0051] This wheel retention unit clip 202 is a component that has a wheel retention unit housing wall 204 formed in a substantially arc shape, centered on a fork axle hole 203 through which the axle 12 is inserted, which is formed on the side surface of the caster fork 200.

[0052] The wheel retention unit housing wall 204 has a contact portion 206 that abuts against the outer circumference of the wheel retention unit 100 when the wheel retention unit 100 is attached to the axle 12. In this modified example 1, since the outer circumference of the wheel retention unit 100 is substantially circular, the shape of the contact portion 206 is also substantially arc-shaped. If the outer circumference of the wheel retention unit 100 is a different shape (for example, rectangular), it is preferable to match the shape of the contact portion 206 to that (for example, rectangular). In addition, although the wheel retention unit housing wall 204 in modified example 1 has a shape in which a part of the lower part is missing, the wheel retention unit housing wall 204 may be formed continuously.

[0053] The upper end of the contact portion 206 (as shown in Figure 13) extends beyond the lower half of the outer circumference shape (approximately circular) of the wheel retention unit 100, and a projection 208 is formed at this end, facing toward the wheel retention unit 100.

[0054] The procedure for attaching the wheel retention unit 100 to the wheel retention unit clip 202 will now be described. As shown in Figure 12, when the axle 12 is inserted through the axle insertion hole 120 of the wheel retention unit 100, approximately half of the wheel retention unit 100 protrudes outward (diagonally upward in the figure) from the wheel retention unit housing wall 204. In addition, the projection 208 is fitted into the retaining recess 126 on the periphery of the retaining portion 112 of the wheel retention unit 100.

[0055] From this state, when the wheel retention unit 100 is moved diagonally downward along the caster fork 200 in the figure, as shown in Figure 13, the axle 12 moves from the axle insertion hole 120 to the notch 122, and at the same time, the wheel retention unit 100 passes over the projection 208 and enters the inside of the wheel retention unit housing wall 204 and comes into contact with the contact portion 206. Note that the wheel retention unit 100 does not need to pass over the projection 208 and enter the inside of the wheel retention unit housing wall 204 and be housed with a clearance, for example, while surrounded by the contact portion 206, and is not limited to coming into contact with the contact portion 206.

[0056] Subsequently, the lid portion 104 is rotated relative to the main body portion 102 to fit the axle insertion hole filling portion 138 into the axle insertion hole 120, thereby completing the installation of the wheel retention unit 100 (see Figure 14).

[0057] In the wheel retention unit clip 202 according to Modification 1, the wheel retention unit housing wall 204, the contact portion 206, and the projection 208 prevent the wheel retention unit 100 from moving undesirably and coming off the axle 12, even if the axle insertion hole filling portion 138 is not fitted into the axle insertion hole 120.

[0058] Furthermore, since a projection 208 is formed on the upper side of the wheel retention unit housing wall 204 and a contact portion 206 is formed on the lower side of the wheel retention unit housing wall 204, there is no risk of the wheel retention unit 100 moving downward due to its own weight and detaching from the axle 12.

[0059] Furthermore, the cover 16 according to the above embodiment and the wheel retention unit clip 202 according to Modification 1 may be used on either the front wheel or the rear wheel of the walker A.

[0060] The invention is not limited to the embodiments disclosed in Embodiment and Modification 1, as long as it is a second means that provides a double layer of protection in addition to the first means for preventing the wheel retention unit 100 from coming off.

[0061] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0062] 10...Wheel unit, 12...Axle, 14...Wheel, 16...Cover 20... Axle groove, 22... Axle hole, 24... Recess (of wheel 14) 100...Wheel retention unit, 102...Main body, 104...Lid 110...Plate-shaped part, 112...Holding part 120...Axle insertion hole, 122...Notch, 124...Axle groove sliding fitting part, 126...Retaining recess, 128...Lid fitting recess, 129...Sliding projection, 130...Rotating hole, 132...Rotating shaft, 134...Lid body, 136...Engaging part, 138...Axle insertion hole filling part, 140...Engaging recess, 142...Biasing surface, 144...Cover body, 146...Fitting projection, 148...Inspection hole, 150...Notch, 152...Engaging projection, 154...Thin-walled part, 156...Engaging recess 200...Caster fork, 202...Wheel retention unit clip, 203...Fork axle hole, 204...Wheel retention unit housing wall, 206...Contact part, 208...Protrusion A...walker, B...leg frame

Claims

1. A wheel retention unit for preventing wheels used in walking aids from coming off the axle, The axle has axle grooves formed in a direction perpendicular to the longitudinal direction. The axle insertion hole through which the axle can be inserted, A notch communicating with the axle insertion hole, A pair of axle groove sliding fitting portions facing each other and spaced apart so as to be able to slide into the axle groove, The axle is located in the notch, and the axle groove is fitted into the axle groove sliding fitting portion, and the axle insertion hole filling portion is fitted into the axle insertion hole. Wheel retention unit.

2. On the side of the axle insertion hole filling portion facing the notch, a biasing surface is formed that pushes the axle toward the back of the notch when the axle insertion hole filling portion is fitted into the axle insertion hole. The wheel retention unit according to claim 1.

3. It comprises the axle insertion hole, the axle groove sliding fitting portion, and the main body portion having the notch, The main body is, The axle insertion hole, the axle groove sliding fitting portion, and the plate-shaped portion with the notch formed therein, The outer side of the plate-like portion has a retaining portion that is thicker than the plate-like portion. The wheel retention unit according to claim 1 or 2.

4. The axle insertion hole, the axle groove sliding fitting portion, and the main body portion having the notch, It has the axle insertion hole filling portion and a lid portion that is rotatably attached to the main body portion, By rotating the lid portion relative to the main body portion, the axle insertion hole filling portion can be inserted into and removed from the axle insertion hole. The wheel retention unit according to claim 1 or 2.

5. An axle in which the axle groove is formed in a direction perpendicular to the longitudinal direction, A wheel attached to the axle, The wheel retaining unit is provided as described in claim 1 or 2. Wheel unit for a walking aid.

6. The wheel unit is provided as described in claim 5. Walking aid.

Images