WO2021074900A2

WO2021074900A2 - A collapsible wheelchair

Info

Publication number: WO2021074900A2
Application number: PCT/IB2020/059788
Authority: WO
Inventors: Adrian Timothy CARD
Original assignee: Ingenuity Aiding Mobility Ltd
Priority date: 2019-10-17
Filing date: 2020-10-18
Publication date: 2021-04-22
Also published as: GB2588887A; GB2588887B; WO2021074900A3; GB201915037D0

Abstract

The invention relates to wheelchairs in particular to collapsible wheelchairs which can be folded for stowage and transport. A collapsible wheelchair comprises: two main wheels each of which is connectable to a T-piece frame member. The T-piece frame members define lateral sides of the wheelchair and a seat is slung between them. A foot well is defined between distal ends of the T-piece members. A junction of the T-piece frame members is defined by a shorter side limb that connects to a longer of two T-piece members. An array of apertures is provided for receiving the main wheels so that each main wheel is capable of being connected to the T-piece frame member at one of a plurality of user selectable positions. The invention enables the wheelchair to be dismantled and readily reassembled or readjusted to suit the size of a user.

Description

A Collapsible Wheelchair

Field of the Invention

The present invention relates to wheelchairs, more particularly but not exclusively, the invention relates to collapsible wheelchairs of the type which can be folded or collapsed for stowage and transport.

Background of the Invneiton

Many existing wheelchairs are cumbersome and can be difficult to stow for storage or transport. However, some types of foldable wheelchairs are designed to be collapsible so as to enable them to be packed away for storage and transportation. This feature is a great benefit when travelling long distances, for example in an automobile, and enables a user arriving at a destination to remove a collapsed wheelchair, which typically has been folded and stowed in the boot or trunk of an automobile, so that it can be assembled quickly and easily for their use or for use by a parent or carer.

Prior Art

An example of a collapsible wheelchair is described in US patent application US 2019/133854 (US Government) wherein a manual wheelchair includes a collapsible frame. At least one brace is connected to at least one of the frame members. A drive wheel axel extends along a first axis of rotation and engages a drive wheel, the first brace and a portion of a transmission means.

A push rim axel extends along a second axis of rotation and engages a push rim wheel and a second brace and a portion of the transmission, which transmits rotation of the push rim to rotation of the drive wheel. At least one of the braces is configured to release one or both of the frame members so as to enable a user to collapse the wheelchair for stowage.

Canadian patent application CA 1039172 (Hallam) discloses a foldable wheelchair which includes a pair of sides each having an upstanding backrest support member, and a soft backrest suspended between both members. Below each member there is mounted a side wheel and a pair of seat supports interconnect the sides. When a bar is drawn forward, the chair is unfolded to provide an extended wheelbase and the respective parts of the chair are locked in place by the weight of a person on the seat. The wheelbase may be shortened, and the chair folded for storage by pushing the bar rearwardly between the sides which folds the seat supports rearwardly and the seat upwardly.

German patent application DE 3 517 050 (Purkott) discloses a wheelchair with perforated plates having holes arranged in a predetermined grid which are located on parts of the chassis frame. The holes are intended to selectively receive a hub axle of a particular drive wheel so that individual adjustment of the wheelchair in terms of height and inclination of the seat is possible.

International patent application WO-A-94/11235 (Doom) discloses a wheelchair construction with a singular main strut T-configuration for supporting the main wheels of the wheelchair in a manner that allows easy positioning of the main wheels in one of a range of positions.

German patent application DE 3 742 547 (Meyra Wilhelm Meyer) discloses a wheelchair with perforated plates which are located on its side frames and which project outwards and which have bearing holes which receive the axle of each rear wheel. The perforated plate is mounted so as to be pivotable at least around one axle on a separate frame which is mounted by means of a spacer device to be displaceable with respect to the frame.

US patent US 4 405 142 (Stainless Medical Products Inc ) teaches a collapsible wheelchair that can be quickly disassembled and reassembled and includes a pair of side frames connectable together by a front frame by means of quick release pins and by a back frame by means of quick release pins with a set of main wheels that are mounted to the respective side frames by means of quick release pins. US patent US 5 480 172 (Quickie Designs Inc) describes a three-wheeled sports wheelchair which has a wheelchair frame with a beam that extends generally from an aft portion to a fore portion thereof.

US patent US 5573260 (Invacare Corp) describes a sports wheelchair which includes a T-frame that interconnects enlarged rear wheels and a single small diameter caster front wheel. A footrest is adjustably secured to the T-frame and may be adjusted height wise and front to rear as desired by the user.

Although successful these types of foldable wheelchairs have tended to be of a nature where they are quite limited in that a user cannot easily vary the size of the wheelchair or the relative position of the seat and a footrest.

Therefore the aforementioned wheelchairs have tended to be of ‘one size fits all’ type, and although popular, have tended to offer limited comfort as they are only suited for a certain sized occupant and so can become relatively uncomfortable for smaller occupants or children especially when used for extended periods.

To overcome this problem different sized wheelchairs had to be built for users, for use from when they were children, through adolescence to adulthood. This has tended to make the aforementioned collapsible wheelchairs more expensive to consumers.

In an attempt to overcome the problem of comfort, smaller occupants have often bulked or padded out the seat back and side spaces with cushioning and other padding, but this often resulted in the occupant sliding out of the seat as they sat too high in the wheelchair. This was sometimes alleviated by using a seatbelt. Larger occupants on the other hand sometimes became cramped due to lack of legroom, because they sat too low in the wheelchair.

An aim of the present invention is to provide a wheelchair which is able to be dismantled and readily reassembled or readjusted.

Another aim of the present invention is to provide a wheelchair which is adjustable to suit the size of a user and to improve their personal comfort. Summary of the Invention

According to a first aspect of the invention there is provided a collapsible wheelchair comprising: two main wheels each of which is connectable to aT-piece frame member, the T-piece frame members define lateral sides of the wheelchair; a seat is slung between the two T-piece frame members and a foot well is defined between distal ends of the T-piece frame members, characterised in that at a junction of the T-piece frame members, where a shorter side limb connects to a longer member of the T -piece frame member, an array of connection points is provided for receiving the main wheels so that each main wheel is capable of being connected to the T-piece frame member at one of a plurality of user selectable positions.

The array of connection points may be protrusions for connection to an item or member with holes or slots formed therein; or the connection points may be apertures for receiving bolts or threaded members on other items.

Ideally a frame is provided between the two T-piece frame members that defines lateral sides of the wheelchair.

In some embodiments the chair is connected to, or formed integrally with, a back rest against which an occupant rests either directly or on a cushion, mattress or soft support. The backrest may be formed from an injection moulded material.

Optionally recycled materials may be used to form the backrest and other portions of the wheelchair that are formed of injection moulding.

In some embodiments each wheel includes a push rim, which is used by an occupant to propel the wheelchair.

Ideally each rim extends around each wheel. Ideally wheels are fitted with quick release connectors and have suspension connections that enable them to flex when connected to the T-piece frame members. This assists in absorbing bumps and shocks. In some embodiments an array of apertures is formed by drilling or punching holes of a size and dimension suitable for receiving a connector or an axle of a main wheel so that the point at which a wheel connects to the frame can be varied.

Optionally the seat is slung from different connection points in the array to those from which the main wheels are connected. A harness or seat support may also be used to support and surround the seat.

Optionally a safety harness or seat belt is fitted to the wheelchair in order to prevent an occupant from falling.

The array of connection points is preferably labelled so that each connection point has a unique address. In some embodiments the array of connection points is labelled with letters for columns and labelled with numerals for rows. Alternatively colours or textured features may be used.

The wheelchair is ideally foldable. The advantages of the collapsible wheelchair are that: it be disassembled in order to be stowed for transportation for example and is adapted to be reconfigured to suit different sized occupants.

These advantages are achieved by repositioning the main wheels at different positions in an array of connection points defined around the junction of the two T-piece frame members so as to suit the height of an occupant and/or the length of their torso and legs.

Optionally connection means for attaching wheels to the frame are of lockable and ideally they are also quick release which enables wheels to be fitted to a frame without any tools by hand.

Optionally the seat is also collapsible and is connected to the two side pieces that make up the frame. The collapsible seat may include a series of concertina side portions and/or sprung side portions which connect to the two side frame pieces so that the seat can expand to fit the space between the lateral sides and optionally a seat rear portion, or back rest, can also extend upwards to accommodate variations in torso length and girth.

Handles are provided to enable a helper, parent or carer to push the wheelchair or manoeuvre the wheelchair. Ideally these handles are adjustable and also removable. The handles, also referred to as push handles, are ideally multi-positional using a ratchet system similar to those used on pushchairs.

Preferably the handles range from a height of around 900 mm for taller carers to a height of around 750 mm, for use by a standard height person.

Handles can be folded down or swivelled to be tucked away parallel with the frame of the wheelchair when not in use. This assists in stowage as well as enables the wheelchair to be customised for occupants as well as for users of different heights and sizes.

Optionally handles may be formed integrally with the T-piece frame members or the handles may be adapted to connect to the lateral sides of the wheelchair so as to be removably attached thereto, for example by way of a clip or push-fit connection.

Brief Description of the Drawings

Figure 1 shows a diagrammatical plan view of an embodiment of a collapsible wheelchair;

Figure 2 shows a diagrammatical front elevational view of the embodiment of the collapsible wheelchair shown in Figure 1 ;

Figure 3 shows a diagrammatical side elevational view of the embodiment of the collapsible wheelchair shown in Figure 1 ;

Figure 4 shows an overall diagrammatical view of the collapsible wheelchair shown in Figure 1 ; Figures 5a, 5b and 5c show plan views of a T-piece frame member in which an array of connection points or apertures is formed at the junction where a shorter side limb connects to a longer member of the T-piece member;

Figure 6 is a plan view of one example of a wheel which may be used with the wheelchair shown in Figure 1 ;

Figure 7 is an overall view of a second embodiment of the wheelchair;

Figure 8 is a side elevational view of a second embodiment of the wheelchair, shown in Figure 7, and depicts varying tipped positions of the seat, tipped forwards and backwards;

Figure 9 shows a side elevational view of an alternative embodiment of the wheelchair, shown in Figure 7, and depicts varying positions of the seat raised and lowered with respect to the main frame; and

Figure 10 shows detailed views of alternative positions of a front wheel and the foot rest, of the alternative embodiment of the wheelchair, shown in Figure 7, the front wheel is connected by way of a quad link suspension assembly.

Detailed Description of Preferred Embodiments of the Invention

Referring to the Figures generally and in particular Figures 1 to 6, there is shown a collapsible wheelchair 10 in an assembled or deployed condition. The wheelchair 10 has a left wheel 12 and a right wheel 14 each respectively connected by quick release connectors 19. The left wheel 12 and right wheel 14 are connected to, and supported by, a T-piece frame member 16a and 16b. The longer limb of each T-piece frame member 16a and 16b is of a generally serpentine form.

The T-piece frame members 16a and 16b are typically formed from steel or a strong composite material which has a high tensile and compressive strength and is lightweight as well as providing strength and rigidity to the wheelchair 10 so as to support other features of the wheelchair 10, such as the seat, back rest and foot well. The seat 22 has a multi-positional ergonomic cushion and squab (seat) with pelvic support utilising a reclining and height adjustable hydraulic mechanism to provide lockable or suspension support along with independently positional arm rests 240 which are interpedently adjustable to improve user comfort. This provides a bespoke wheelchair for users of different sizes, differing masses and heights.

Referring to Figure 5a, 5b and 5c, it is apparent that the shorter side limb 17 connects to the longer serpentine frame member, at a junction where an array of connection points, which are shown as apertures 20 in this embodiment. The feature of the variable position as a consequence of the different connection points, ensures easy adjustment of the size of the wheelchair and its centre of gravity. The wheels 12 and 14 connect to the T-piece frame member by way of connection devices, such as bolts (not shown) which pass through specific apertures and are locked thereto by way of nuts (not shown).

In a preferred arrangement the apertures 20, formed on each T-piece frame member are provided in a labelled array. Each aperture is typically labelled with an address, for example each row may be labelled with letters, such as ‘A’, ‘B’ and Ό’ etc, and each column may be labelled with numerals, such as , ‘2’ and ‘3’ etc.

The T-piece frame members are ideally curved in appearance and extend from a handle to a foot rest as a continuous casting or moulding. A track and clamp system is received within the overall space defined by the wheelchair frame with universal fittings which permit items and components to be attached to the T-piece frame members at one of a plurality of user selectable positions.

The position and orientation of the front wheel, foot rests, seat and hydraulic shock absorber may be configured to be dismantled for stowage either for transport or long term storage or packing. The flexible arrangement that enables wheelchair components can be fitted to various positions on the T-piece frame member also enables them to be slid up or down the frame members thereby enabling a user to customise a bespoke wheelchair for each occupant. As a child grows they become taller and heavier and they alter the centre of gravity when they sit and recline in the wheelchair. As this happens a wheelchair occupant’s centre of gravity alters as they grow taller and their legs longer. As a consequence of these changes in physique of an occupant the centre of gravity of the wheelchair varies. By enabling the user to vary the position of where wheels connect to the frame, the tipping point of for a wheelchair can be altered in order to compensate this.

These features enable variation of the points at which wheels connect to and are positioned on the wheelchair 110, enables connection of the components of the wheelchair to be changed according to the shape and size of an occupant. These features are deemed to be important because they enable different sized users to use the wheelchair or the same user to use the wheelchair throughout the period of growth, for example during puberty and their early teens when there are often relatively rapid changes in size and weight of an occupant.

This labelling ensures that positions at which, for example the wheels are connected to one side of the wheelchair, are the same on the other side so that they match the same orientation and position; otherwise the wheelchair would be lop-sided.

A purpose of the apertures therefore enables a user to vary the configuration of their wheelchair in order to accommodate physiological changes in their torso and legs as they grow.

Ideally the seat 22 and/or back rest 18 are both connected to the T-piece frame members 16a and 16b by way of click fit, push-fit or similar type quick release connectors.

In order to retain a degree of stability it is necessary for a notional plumb line, at the centre of gravity of the wheelchair, when in use, to remain within an area of the wheel base as defined by the points where the two larger wheels and the smaller front wheel are in contact with a surface, over which the wheelchair travels.

Figures 7 to 10 show an alternative embodiment of a wheelchair in which like parts have been indicated using the same reference numerals as in Figures 1 to 6. Figure 7 shows an overall view of a second embodiment of the wheelchair 100 and depicts left wheel 120 and right rear wheel 140. Wheels may comprise tubeless self sealing latex type tyres which allow for lower operational pressure. Tyres may be supplied in a range of sizes, such 24 inches, 26 inches, 27.5 inches and 29 inches. The T-piece main frame members 160a and 160b show how they support seat 220, back rest 180 and arms rests 240. Front wheel 260 is supported on a quad link suspension 255. A foot rest 270 is located above the front wheel 260 is a broad tubeless tyre with self-sealing latex to reduce or avoid punctures and permit operation at lower pressures, thereby providing a smoother ride.

Figure 8 shows is a side elevational view of an alternative embodiment of the wheelchair 100 and illustrates varying positions of the seat 220 with respect to the main T-piece main frame members 160a and 160b. One or more hydraulic dampers 275 enables adjustment of the inclination of the back rest 180 of the chair and may be used to cushion the back rest 180 of the wheelchair 100 and to absorb shocks as well providing an ergonomic seat, back and pelvic support which is adjustable.

A right hand hydraulic disc brake 280 is shown supported on the shorter side limb member 170 from a main T-piece frame member 160a, which is also referred to as a main frame member, as each provides structural strength and integrity to the wheelchair. Variation of the position of connection of the wheels and seat 220 to each of the T-piece frame members 160a and 160b the seat 220 and back rest 180 are depicted in different positions which are shown in Figures 8, 9 and 10 and the wheelchair 100 is seen in different configurations.

Figure 7 shows how adjustable wheels 120 and 140 splay and widen in order to increase the size of the wheel base which improves stability and aids manoeuvrability.

Figure 8 shows how the arm rests 240 are independent and adjustable and can be reclined in order to accommodate multi point brake levers (not shown) or actuators (not shown) for driving and/or steering a powered version of the wheelchair in order to adapt to limitations in arm or hand use. Figures 8 and 9 together illustrate, in ghost lines, how the wheelchair 100 is able to be adjusted in order to vary the reclining position of the seat 220 and to raise, to lower or to tip the arm rests 240 (Figure 8) in order to adopt different positions according to the size and weight of the occupant and to improve their comfort.

Figure 9 shows a side elevation of the alternative embodiment of the wheelchair 100 and how by varying the position of attachment of the seat 220 to the T-piece frame members 160a and 160b, different configurations enable the height of the back rest 180 to be varied (d-i). Arm rests 240 are shown in a plurality of different positions. By varying the position of attachment of the seat 220 to the T -piece frame members 160a and 160b the seat 220 and the arm rests 240 can be raised and lowered, on both sides of the wheel chair, and this is indicated by the variable distance (d2) shown in Figure 9.

Connection of the wheels 120 and 140 and the seat 220, back rest 180 and arm rests 240 with the T-piece main frame members 160a and 160b, shown in Figures 5a, 5b and 5c enable repositioning of the seat 220 and the back rest 180 in a range of different positions to suit occupant and carer.

Figure 10 shows a detailed view of alternative positions of the front wheel 260 and foot rest 270 which are achieved by way of the quad link suspension 255 is designed to aid comfort and performance on uneven terrain.

Referring to Figures 9 and 10, a multi-positional front wheel 260 is varied in order to shorten lengthen the wheelbase. A quad link suspension 255 is designed to aid comfort and performance on uneven terrain.

Optionally hydraulic disc brakes 280 may be provided, and these are controlled by multi point brake levers. Brake levers and control means may be provided on the arm rest or a part of a main frame.

Multi-positional and one or more extendable foot rests 270 aid comfort by providing a wider range of adjustable leg lengths to the user and enable independent adjustment of each of the extendable foot rests 270 improves comfort. Referring to Figures 9 and 10, the foot rests 270 are optionally designed to be interchangeable or a foot rest may be customised to be bespoke to the left and right side.

Ideally the foot rests 270 are removable for repair, replacement and stowage. In some embodiments the footrest and a footwell may be formed form a synthetic plastics material which may be formed from recycled plastics material.

Optionally lights, such as light emitting diodes (LEDs), may be positioned on the wheelchair. Lights may be placed to the front and/or rear of the wheelchair so as to assist a user or operator to see and to be seen.

Optionally the seat 22 and/or back rest 18 are formed from a polycarbonate plastics material which is a thermoplastics polymer that can be made to be completely translucent or coloured with a suitable dyestuff. This synthetic plastics material is commonly used in a ‘see through’ or transparent form.

Another synthetic plastics material, from which many of the components may be made, is acrylonitrile butadiene styrene (ABS) which is a widely used thermoplastic.

Another synthetic plastics material, from which many of the components may be made; polymer polydicyclopentadiene (pDCPD) is a thermoset plastics which is structurally resistant to extreme temperatures.

Components of the wheelchair may also be formed from steel or an alloy or a composite materials such as a carbon fibre or high density polymer.

Optionally a bell or horn may be provided in order to attract attention.

Optionally a drinks holder may also be provided so as to help an occupant to remain hydrated. Optionally pockets or pouches may be provided in side panels or arms of the wheel chair so as to hold personal items and effects, such as a mobile telephone, suncream, medicaments or sunglasses. Pockets may be lockable or include a locking device (not shown) to prevent such items as mobile telephones from being accidentally removed, lost or stolen.

A servo assisted option may be provided for manual wheel chairs to enable the wheel chair to roll further with each normal push cycle.

The invention has been described by way of example only and it will be appreciated that variation may be made without departing from the scope of protection as defined by the claims.

Parts List

10 wheelchair

12 left wheel 12

14 right wheel 14

16a and 16b T-piece frame members

17 shorter side limb member

18 back rest

19 connectors

20 apertures 22 seat 24 arm rests 26 front wheel

27 foot well

28 handles 29 push rim 100 wheelchair 120 left wheel 12 128 handles 140 right wheel 14

160a and 160b T-piece frame members 170 shorter side limb member 180 back rest 190 connectors 200 apertures 220 seat 240 arm rests 255 quad link suspension 260 multi-positional front wheel 270 foot rest 275 hydraulic damper 280 hydraulic disc brakes

Claims

1. A collapsible wheelchair comprises: two main wheels each of which is connectable to a T-piece frame member, the T-piece frame members define lateral sides of the wheelchair; a seat is slung between the two T-piece frame members and a foot well is defined between distal ends of the T-piece frame members, characterised in that at a junction of the T-piece frame members, where a shorter side limb connects to a longer member of the T-piece frame member, an array of connection points is provided for receiving the main wheels so that each main wheel is capable of being connected to the T-piece frame member at one of a plurality of user selectable positions.

2. A wheelchair according to claim 1 wherein the array of connection points comprises protrusions for connection to an item or member with holes or slots formed therein.

3. A wheelchair according to claim 1 wherein the array of connection points comprises holes or slots formed therein for receiving bolts or threaded members.

4. A wheelchair according to any preceding claim wherein each wheel includes a push rim extending around the wheel.

5. A wheelchair according to claim 1 or 2 wherein the array of apertures is formed by drilling or punching holes of a size and dimension suitable for receiving a connector or an axle of a main wheel.

6. A wheelchair according to any preceding claim wherein the seat is slung from connection points in the array to those from which the main wheels are connected.

7. A wheelchair according to any preceding claim wherein the back rest is slung from the same connection points in the array as those from where the main wheels are connected.

8. A wheelchair according to any preceding claim wherein each connection point is labelled with a unique address.

9. A wheelchair according to claim 8 wherein points are labelled with letters or with textured features to indicate columns and with numerals or with textured features to indicate rows.

10. A wheelchair according to any preceding claim wherein the two main wheels are formed from a composite material.

11. A wheelchair according to any preceding claim wherein each T-piece frame member is formed from a composite material or steel.

12. A wheelchair according to any preceding claim wherein the seat is formed from a composite material.

13. A wheelchair according to any preceding claim wherein the back rest is formed from a composite material.

14. A wheelchair according to any preceding claim wherein the foot well, defined between distal ends of the T-piece frame members is formed from a composite material.

15. A wheelchair according to any of claims 10 to 14 wherein the composite material includes a synthetic plastics material which is acrylonitrile butadiene styrene (ABS).

16. A wheelchair according to any of claims 8 to 14 wherein the composite material includes a synthetic plastics material which is a thermoplastic polymer, such as polydicyclopentadiene (pDCPD).

17. A wheelchair according to any of claims 10 to 14 wherein the composite material includes a carbon fibre or high density polymer.

18. A wheelchair according to any preceding claim which is motorised.

19. A wheelchair according to claim 18 which includes a rechargeable battery.

20. A wheelchair according to any preceding claim includes at least one hydraulic damper which absorbs forces on the seat and/or back rest.

21.A wheelchair according to any preceding claim includes at least one hydraulic disc brake.

22. A wheelchair according to any preceding claim wherein the wheels have pneumatic tyres, preferably tubeless pneumatic tyres.

23. A wheelchair according to any preceding claim includes at least one quad link that supports a front wheel.