WO2017031530A1

WO2017031530A1 - A wheel assembly for a wheelchair

Info

Publication number: WO2017031530A1
Application number: PCT/AU2016/050570
Authority: WO
Inventors: Brad FORTUNE; John OTAGO
Original assignee: Technology Assisting Disability Wa Inc (tadwa)
Current assignee: Technology Assisting Disability Wa Inc (tadwa)
Priority date: 2015-08-21
Filing date: 2016-06-30
Publication date: 2017-03-02
Anticipated expiration: 2018-02-21

Abstract

Provided is a wheel assembly (10), which finds particular application for use with a wheelchair (30). The wheel assembly (12) typically comprises an inner hub (12) which is configured for attachment to the wheelchair (30), along with an outer rim (14) which generally defines a contact surface (16). The wheel assembly (10) further comprises a plurality of spokes 18 that supports the outer rim (14) on the inner hub (12). The spokes (18) are generally configured to extend between the hub (12) and the rim (14) in an arcuate manner, with a bulge (24) of each spoke's arc directed away from a preferred direction of rotation of the wheel assembly (10). This configuration produces a digging, scooping or paddling action when the wheel assembly (10) travels through a particulate material, such as sand, soft soil, snow, etc., or a liquid, such as water.

Description

Ά WHEEL ASSEMBLY FOR Ά WHEELCHAIR

TECHNICAL FIELD

[0001] This invention relates to a wheelchair, a wheel assembly for a wheelchair, a method of transporting a person in a wheelchair, a method for converting a wheelchair for travel over a surface, and a method of manufacturing a wheel assembly .

BACKGROUND ART

[0002] The following discussion of the background art is intended to facilitate an understanding of the present invention only. The discussion is not an acknowledgement or admission that any of the material referred to is or was part of the common general knowledge as at the priority date of the application.

[0003] Wheelchairs, as generally used to assist mobility- restricted people, are known in the art. There is an ongoing need in the art, however, for wheelchairs that are able to travel on sand, snow, and other soft soils or similar unstable surfaces.

[0004] Conventionally, in order to address this need, some examples of wheelchairs include low-pressure balloon-type wheels that are typically so soft in order to facilitate rolling over soft or unstable surfaces. This effect is generally achieved with an increased contact patch between the larger balloon wheel and the surface, wherein the wheels flatten in order to roll over sand, snow or other unstable surfaces where conventional wheels would become stuck.

[0005] Further examples include wheelchairs with non- pneumatic tires (NPT) , or airless tires, which are tires that are not supported by air pressure. A major advantage of airless tires is that they cannot go flat, which finds particular application in wheelchair use where a user already suffers from reduced mobility and would typically not be able to attend to pneumatic punctures, or the like.

[0006] The Applicants have identified a need in the art for a wheelchair with improved travel capability over soft or unstable surfaces. The following disclosure seeks to propose possible improvements, at least in part, to conventional wheelchairs and associated wheels for travel across soft or unstable surfaces.

SUMMARY OF THE INVENTION

[0007] According to a first aspect of the invention there is provided a wheelchair comprising:

a frame;

a seat arrangement for operatively receiving a user; and at least two wheel assemblies supporting the frame, in use, each wheel assembly comprising an inner hub configured for attachment to the frame, an outer rim defining a contact surface, and a plurality of spokes supporting said outer rim on the inner hub, wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly to facilitate a digging action when the wheel assembly travels across or through a particulate material or a liquid.

[0008] In one example, the contact surface of the outer rim may be peaked. The contact surface may be peaked by being shaped as an arc, having a bevelled peak, or the like.

[0009] Typically, the outer rim overhangs the spokes and inner hub by being flanged.

[0010] Typically, the spokes are manufactured from a resiliently deformable material to facilitate shock- absorption .

[0011] Preferably, the wheel assembly is manufactured via a polymer injection moulding process.

[0012] Typically, the frame comprises an axle for receiving each wheel assembly.

[0013] According to a second aspect of the invention there is provided a wheel assembly for a wheelchair, said wheel assembly comprising:

an inner hub configured for attachment to the wheelchair;

an outer rim defining a contact surface; and

a plurality of spokes supporting said outer rim on the inner hub;

wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly in order to produce a digging action when the wheel assembly travels through a particulate material or through a liquid .

[0014] Typically, the contact surface of the outer rim may be peaked. The contact surface may be peaked by being shaped as an arc, having a bevelled peak, or the like.

[0015] Typically, the outer rim overhangs the spokes and inner hub by being flanged.

[0016] Typically, the spokes are manufactured from a resiliently deformable material to facilitate shock- absorption .

[0017] Typically, the wheel assembly is manufactured as a single unit via a polymer injection moulding process.

[0018] According to a third aspect of the invention there is provided a method of transporting a person in a wheelchair, said method comprising the steps of:

positioning the person in a wheelchair having a frame and a seat arrangement for operatively receiving such user, and at least two wheel assemblies supporting the frame, in use, each wheel assembly comprising an inner hub configured for attachment to the frame, an outer rim defining a contact surface, and a plurality of spokes supporting said outer rim on the inner hub, wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly in order to produce a digging action when the wheel assembly travels through a particulate material or through a liquid; and

urging said wheelchair over a surface.

[0019] According to a fourth aspect of the invention there is provided a method for converting a wheelchair for travel over a surface, said method comprising the steps of:

removing at least two conventional wheels from the wheelchair; and

replacing a removed wheel with a wheel assembly comprising an inner hub configured for attachment to the wheelchair, an outer rim defining a contact surface, and a plurality of spokes supporting said outer rim on the inner hub, wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly in order to produce a digging action when the wheel assembly travels through a particulate material or through a liquid .

[0020] According to a fifth aspect of the invention there is provided a method of manufacturing a wheel assembly, said method comprising the step of polymer injection moulding a wheel assembly comprising an inner hub configured for attachment to a wheelchair, an outer rim defining a contact surface, and a plurality of spokes supporting said outer rim on the inner hub, wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly in order to produce a digging action when the wheel assembly travels through a particulate material or through a liquid.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Further features of the present invention are more fully described in the following description of several non- limiting embodiments thereof. This description is included solely for the purposes of exemplifying the present invention. It should not be understood as a restriction on the broad summary, disclosure or description of the invention as set out above. The description will be made with reference to the accompanying drawings in which:

Figure 1 is a side representation of one example of a wheel assembly in accordance with an aspect of the invention;

Figure 2 is a front cross-sectional representation along line 2-2 of the wheel assembly of Figure 1; and

Figure 3 is side view diagrammatic representation of a wheelchair in accordance with an aspect of the invention.

DESCRIPTION OF EMBODIMENTS

[0022] The following modes, given by way of example only, are described in order to provide a more precise understanding of the subject matter of a preferred embodiment or embodiments.

[0023] In the figures, incorporated to illustrate features of an example embodiment, like reference numerals are used to identify like parts throughout the figures. [0024 ] The accompanying figures show an example of a wheel assembly 10, which finds particular application for use with a wheelchair 30. The wheel assembly 12 typically comprises an inner hub 12 which is configured for attachment to the wheelchair 30, along with an outer rim 14 which generally defines a contact surface 16.

[ 0025 ] The wheel assembly 10 further comprises a plurality of spokes 18 that supports the outer rim 14 on the inner hub 12, as shown. The spokes 18 are generally configured to extend between the hub 12 and the rim 14 in an arcuate manner, with a bulge 24 of each spoke's arc directed away from a preferred direction of rotation of the wheel assembly 10. Such a preferred direction of travel and rotation are indicated by the respective arrows shown in Figure 1.

[ 0026] Importantly, this configuration produces a digging, scooping or paddling action when the wheel assembly 10 travels through a particulate material, such as sand, soft soil, snow, etc., or a liquid, such as water. Furthermore, the wheel assembly 10 suffers no ill effect, such as a potentially destabilizing buoyancy force experienced with pneumatic tyres, when the wheel assembly 10 is driven into, or submerged under, water.

[ 0027 ] Preferably, the outer rim 14 is configured to overhang the spokes 18 and the inner hub 12, as shown. The outer rim 14 generally overhangs the spokes 18 and inner hub 12 by being flanged 20. By being flanged 20 in this manner, the outer rim 14 has an increased surface area or footprint, which aids in preventing particulate material from reaching the spokes 18. [0028] In one embodiment, the contact surface 16 of the outer rim 14 is peaked 22, as shown. In different embodiments, the contact surface 16 may be peaked by being shaped as an arc, having a bevelled peak, or the like. Such a peak 22 can be helpful when the wheel assembly 10 traverses particulate material, or the like. For example, the peak 22 of the contact surface 16 finds particular application when the wheel assembly 10 travels across beach sand, as it typically assists in displacing particulate matter in such a manner that the wheel assembly 10 can travel more easily across such matter.

[0029] Typically, the spokes 18 are manufactured from a resiliently deformable material to facilitate shock- absorption. In a preferred embodiment, the entire wheel assembly 10 is manufactured from a resiliently deformable polymer material, such as polyethylene, or the like. The wheel assembly 10 is typically manufactured as a single unit by means of a polymer injection moulding process.

[0030] It is to be appreciated that having the entire wheel assembly 10 manufactured from a polymer material completely removes the danger of a puncture which would otherwise severely impede the functioning of a pneumatic tyre or wheel .

[0031] Figure 3 shows an example of a wheelchair 30 that comprises a frame 32 and a seat arrangement 34 for operatively receiving a user 36. The wheelchair 30 generally comprises at least two of the wheel assemblies 10 that support the frame 32, as shown. [0032] In the example of Figure 3 the wheel assembly 10 is not deformed under the weight of the user 36. However, it is to be appreciated that the material out of which the wheel assembly 10 is manufactured can be chosen to provide different levels of resiliency, depending on the user' s weight, intended application or particulate surface material on which the wheelchair 30 is to be used, or the like.

[0033] For example, a more resiliently deformable material can be used for a wheel assembly 10 to be used on soft beach sand, or the like. This will typically cause the wheel assembly 10 to deform under the weight of the user 36 in such a manner that the wheel assembly 10 provides a much larger footprint or contact patch when used on beach sand, or the like. Similarly, a less resiliently deformable material can be used to support a large man as that compared to a small child, or the like.

[0034] The invention also encompasses an associated method of transporting a person 36 in a wheelchair 30, where the person 36 is positioned in the wheelchair 30 and urged over a surface, such as beach sand, or the like.

[0035] It is to be appreciated that the invention further encompasses a method for converting a conventional wheelchair, where at least two conventional wheels are removed from the wheelchair and replaced with the wheel assembly 10, as described above.

[0036] Applicants believe it advantageous that the wheel assembly 10 improves travel of a wheelchair 30 across a particulate material, such as beach sand, and that the wheel assembly 10 can easily travel into water, such as the ocean, without experiencing buoyancy or other ill effects that may adversely affect the wheelchair 30 or the performance thereof .

[ 0037 ] Optional embodiments of the present invention may also be said to broadly consist in the parts, elements and features referred to or indicated herein, individually or collectively, in any or all combinations of two or more of the parts, elements or features, and wherein specific integers are mentioned herein which have known equivalents in the art to which the invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

[ 0038 ] It is to be appreciated that reference to "one example" or "an example" of the invention is not made in an exclusive sense. Accordingly, one example may exemplify certain aspects of the invention, whilst other aspects are exemplified in a different example. These examples are intended to assist the skilled person in performing the invention and are not intended to limit the overall scope of the invention in any way unless the context clearly indicates otherwise .

[ 0039 ] It is to be understood that the terminology employed above is for the purpose of description and should not be regarded as limiting. The described embodiment is intended to be illustrative of the invention, without limiting the scope thereof. The invention is capable of being practised with various modifications and additions as will readily occur to those skilled in the art. [0040] Various substantially and specifically practical and useful exemplary embodiments of the claimed subject matter are described herein, textually and/or graphically, including the best mode, if any, known to the inventors for carrying out the claimed subject matter. Variations (e.g. modifications and/or enhancements) of one or more embodiments described herein might become apparent to those of ordinary skill in the art upon reading this application.

[0041] The inventor (s) expects skilled artisans to employ such variations as appropriate, and the inventor (s) intends for the claimed subject matter to be practiced other than as specifically described herein. Accordingly, as permitted by law, the claimed subject matter includes and covers all equivalents of the claimed subject matter and all improvements to the claimed subject matter. Moreover, every combination of the above described elements, activities, and all possible variations thereof are encompassed by the claimed subject matter unless otherwise clearly indicated herein, clearly and specifically disclaimed, or otherwise clearly contradicted by context.

[0042] The use of any and all examples, or exemplary language (e.g., "such as") provided herein, is intended merely to better illuminate one or more embodiments and does not pose a limitation on the scope of any claimed subject matter unless otherwise stated. No language in the specification should be construed as indicating any non- claimed subject matter as essential to the practice of the claimed subject matter. [ 0043 ] The use of words that indicate orientation or direction of travel is not to be considered limiting. Thus, words such as "front", "back", "rear", "side", "up", down", "upper", "lower", "top", "bottom", "forwards", "backwards", "towards", "distal", "proximal", "in", "out" and synonyms, antonyms and derivatives thereof have been selected for convenience only, unless the context indicates otherwise. The inventor (s) envisage that various exemplary embodiments of the claimed subject matter can be supplied in any particular orientation and the claimed subject matter is intended to include such orientations.

[ 0044 ] The use of the terms "a", "an", "said", "the", and/or similar referents in the context of describing various embodiments (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. The terms "comprising," "having," "including," and "containing" are to be construed as open- ended terms (i.e., meaning "including, but not limited to,") unless otherwise noted.

[ 0045 ] Moreover, when any number or range is described herein, unless clearly stated otherwise, that number or range is approximate. Recitation of ranges of values herein are merely intended to serve as a shorthand method of referring individually to each separate value falling within the range, unless otherwise indicated herein, and each separate value and each separate sub-range defined by such separate values is incorporated into the specification as if it were individually recited herein. For example, if a range of 1 to 10 is described, that range includes all values there between, such as for example, 1.1, 2.5, 3.335, 5, 6.179, 8.9999, etc., and includes all sub-ranges there between, such as for example, 1 to 3.65, 2.8 to 8.14, 1.93 to 9, etc.

[0046] Accordingly, every portion (e.g., title, field, background, summary, description, abstract, drawing figure, etc.) of this application, other than the claims themselves, is to be regarded as illustrative in nature, and not as restrictive; and the scope of subject matter protected by any patent that issues based on this application is defined only by the claims of that patent.

Claims

1 . A wheelchair comprising:

a frame;

a seat arrangement for operatively receiving a user; and

at least two wheel assemblies supporting the frame, in use, each wheel assembly comprising an inner hub configured for attachment to the frame, an outer rim defining a contact surface, and a plurality of spokes supporting said outer rim on the inner hub, wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly to facilitate a digging action when the wheel assembly travels across or through a particulate material or a liquid.

2 . The wheelchair of claim 1, wherein the contact surface of the outer rim is peaked.

3. The wheelchair of claim 2, wherein the contact surface is peaked by being shaped as an arc, having a bevelled peak.

4 . The wheelchair of any of claims 1 to 3, wherein the outer rim overhangs the spokes and inner hub by being flanged .

5 . The wheelchair of any of claims 1 to 4, wherein the spokes are manufactured from a resiliently deformable material to facilitate shock-absorption.

6. The wheelchair of any of claims 1 to 5, wherein the wheel assembly is manufactured via a polymer injection moulding process.

7. The wheelchair of any of claims 1 to 6, wherein the frame comprises an axle for receiving each wheel assembly.

8. A wheel assembly for a wheelchair, said wheel assembly comprising :

an inner hub configured for attachment to the wheelchair;

an outer rim defining a contact surface; and

a plurality of spokes supporting said outer rim on the inner hub;

9. The wheel assembly of claim 8, wherein the contact surface of the outer rim is peaked.

10. The wheel assembly of claim 9, wherein the contact surface is peaked by being shaped as an arc, having a bevelled peak.

11. The wheel assembly of any of claims 8 to 10, wherein the outer rim overhangs the spokes and inner hub by being flanged .

12. The wheel assembly of any of claims 8 to 11, wherein the spokes are manufactured from a resiliently deformable material to facilitate shock-absorption.

13. The wheel assembly of any of claims 8 to 12, which is manufactured as a single unit via a polymer injection moulding process.

14. A method of transporting a person in a wheelchair, said method comprising the steps of:

urging said wheelchair over a surface.

15. A method for converting a wheelchair for travel over a surface, said method comprising the steps of:

removing at least two conventional wheels from the wheelchair; and

16 . A method of manufacturing a wheel assembly, said method comprising the step of polymer injection moulding a wheel assembly comprising an inner hub configured for attachment to a wheelchair, an outer rim defining a contact surface, and a plurality of spokes supporting said outer rim on the inner hub, wherein the outer rim is configured to overhang the spokes and the inner hub, said spokes arcuately extending from the hub to the rim with a bulge of each arc directed away from a preferred direction of rotation of the wheel assembly in order to produce a digging action when the wheel assembly travels through a particulate material or through a liquid.