WO2019053453A1

WO2019053453A1 - Wheelchair

Info

Publication number: WO2019053453A1
Application number: PCT/GB2018/052628
Authority: WO
Inventors: Joshua Nicholas George REID
Original assignee: Poolpod Products Ltd
Priority date: 2017-09-14
Filing date: 2018-09-14
Publication date: 2019-03-21
Also published as: GB2581623A; GB2566482A; GB202005267D0; GB201714812D0; GB2581623B

Abstract

A wheelchair (10) comprises a chassis (12) formed of two spaced-apart side members (30, 32) and a transverse cross-member (34). The transverse cross member (34) connects the side members (30, 32) to form the chassis (12). The transverse cross member (34) is connected to each side member (30, 32) towards the top and towards the front of each side member (30, 32). The front wheels (24R, 24L) connect to the front of each side member (30, 32) and the rear wheels (22R, 22L) connect to the rear of each side member (30, 32) and a leading edge of the seat assembly (14) is connected to the chassis (12) proximate the transverse cross member (34).

Description

WHEELCHAIR

FIELD OF THE INVENTION

The present invention relates to a wheelchair. In particular, but not exclusively, the present invention relates to a wheelchair adaptable and adjustable to suit various users and facilities.

BACKGROUND TO THE INVENTION

People with restricted mobility and people with certain disabilities may on occasion or regularly need to use a wheelchair to transport themselves or to be transported from one place to another. Some people with restricted mobility may only use a wheelchair occasionally for longer distances or when they wish to feel more secure and comfortable. Each user has their own set of anthropometric and medical requirements based around a large set of variables.

Current wheelchairs optimise their designs around a particular set of users, for example some wheelchairs incorporate tilting features, other wheelchairs can be function specific, for example for use in a shower. Some wheelchairs are designed for children's proportions, while some are designed for obese people; it will be appreciated, wheelchairs that are large enough for obese people do not provide sufficient support for a child.

There are several situations where wheelchairs are provided for temporary use or incidental use, for example in an airport, swimming pool, visitor attractions, hotels, shopping malls and so on.

It may be an object of one or more aspects, examples, embodiments or claims of the present disclosure to solve or at least mitigate one or more of the problems of the prior art, such as herein described or otherwise.

SUMMARY

Known wheelchairs incorporate adjustable features to accommodate a range of user requirements within their chosen market segment but do not accommodate a wide range of users. As such, a provider, such as a theme park or hospital often requires a range of wheelchairs to suit a range of needs or a range of wheelchairs for a specific group of users, which means that some users are excluded.

In certain locations, for example a theme park, it will be appreciated that using wheelchairs with a small range of adjustment is less efficient than using a wheelchair with a wide range of adjustment because a large number of children may arrive at one time. Typically, wheelchairs are not easily reconfigurable between child and adult proportions without attaching or removing additional parts during reconfiguration. It will be appreciated that this activity can be time-consuming and detachable parts may become lost.

As noted above, known wheelchair designs are typically optimised around a single usage environment. For example, they are suitable for ordinary outdoor use, or suitable for showering, or for use in a swimming pool, or they are easy to secure in a vehicle.

A swimming pool is an example of an environment in which a wheelchair may be used. Typically, a wheelchair for use in a swimming pool environment has a low back rest, which does not provide sufficient support for a disabled occupant with a higher level of

dependency. Some specialist swimming pool wheelchairs are known such as tilting swimming pool wheelchairs and fully horizontal swimming pool wheelchairs, but as discussed above these are typically optimised around a specific function, for example tilting.

Typically, these wheelchairs comprise a narrow range of features, which means that swimming pools wishing to cater for a wide range of disabled users, for example users with restricted mobility, would require several wheelchairs to cater for the needs of all users.

Most swimming pools fail to provide wheelchairs suitable for children with disabilities. This means that very often children do not get the opportunity to engage with water-borne activity until later in life. This is far from an ideal situation, because it is well known that swimming and water borne activity can be particularly beneficial for people with restricted mobility and can have positive effects and therapeutic benefit.

It may be an object of one or more aspects, examples or embodiments of the present disclosure to provide a wheelchair configured for use by a range of users of various sizes and proportions and for users with restricted mobility and/or various forms of disability.

An aspect of the present invention provides a wheelchair. The wheelchair may comprise a chassis. The wheelchair may comprise one or more front wheels, such as a pair of front wheels. The wheelchair may comprise one or more rear wheels, such as a pair of rear wheels. The chassis may comprise two spaced-apart side members. The chassis may comprise a transverse cross-member connecting the side members. The transverse cross member may be connected to each side member. The transverse cross member may be connected to each side member towards the top of each side member. It will be appreciated that the top of the side member may comprise a position at or towards a maximum height of the side member, such as a portion of the side member furthest from the ground. The transverse cross member may be connected to each side member towards the front of each side member. It will be appreciated that the front of the side member may comprise a position at or towards a foremost portion of the side member, such as a portion of the side member proximal a front wheel. The front of the side member may be located at or in a front half of the wheelchair. The wheelchair may comprise a seat assembly. The seat assembly may comprise a leading edge. The leading edge of the seat assembly may be connected to the chassis proximate the transverse cross member.

In at least one example, the wheelchair comprises a chassis, front wheels, rear wheels and a seat assembly, wherein the front wheels, rear wheels and seat assembly are connectable to the chassis and wherein the chassis comprises two spaced-apart side members and a transverse cross-member connecting the side members, wherein the transverse cross member is connected to each side member towards the top and towards the front of each side member, and wherein a leading edge of the seat is connected to the chassis proximate the transverse cross member.

An advantage of locating the transverse member high and forward on the chassis, may be that the configuration of the wheelchair can comprise an open structure, free of transverse obstructions, which facilitates locating the wheelchair over a lavatory bowl and facilitates rearward reclining of the seat assembly.

An advantage of the configuration of the chassis may be that the seat assembly can be pivotally mounted relative to the transverse cross member and the envelope of rotation of the seat assembly can be increased compared with conventional chassis configurations.

Each side of the wheelchair may comprise a single side member positioned towards each respective side of the wheelchair. For example, the wheelchair may comprise a single left side member and a single right side member.

Each side member may connect the respective front wheel to the rear wheel on the associated side of the wheelchair. The top of the side member may be defined by an intermediate portion of the side member. The top of the side member may be positioned at a height above the front wheel. The top of the side member may be positioned directly above the front wheel. In at least some examples, the top of the side member may be located rearwards of front wheel.

The top of the/each side member may correspond to a user-related height, such as corresponding to a height or position of a knee joint of a user when located in or on the wheelchair.

When the wheelchair is viewed from the side, the/each side member may define an A- shape. A front portion of the side member may define a fore lowermost point of the side member. A rear portion of the side member may define a rear lowermost point of the side member. The top of the side member may be defined by an apex, such as when viewed from the side. The apex may comprise the intermediate portion of the side member, between the front and rear portions of the side member. The fore lowermost point of the front portion of the side member may be lower than the rear lowermost point of the rear portion of the side member, such as where the rear wheel comprises a higher pivot axis than the front wheel (e.g. where the rear wheel has a larger diameter than the front wheel). The apex of the side member may be at or of a similar height to the leading edge of the seat and/or of the knee-joint of the user.

The front portion may extend from the apex downwards to the front wheel. The front portion may be inclined at an angle from horizontal of greater than 45 degrees, optionally greater than 60 degrees, optionally greater than 75 degrees. Accordingly, the top of the side member may be located towards a forward part of the side member (e.g. towards the front end of the wheelchair).

The transverse cross member may be positioned at a height proximal to or corresponding to the leading edge - at least at or towards a central portion of the transverse member, such as at or towards a laterally central portion of the wheelchair (e.g. between or equidistant the side members). Accordingly, at least the chassis, optionally the wheelchair as such, may comprise or define a void or open space beneath the seat portion - at least at or towards the front or a front half of the wheelchair. The void or open space may be free from obstruction between the ground and the transverse member and/or between the ground and the seat portion.

The transverse member may be positioned at a single height. For example, the transverse cross member may extend horizontally between the side members.

The seat assembly may be pivotally connected to the chassis such that it is pivotal relative to the transverse cross member between a rearward inclined configuration and an upright position, wherein the upright position is between substantially horizontal and a forward inclined position. The seat assembly may be connected at the leading edge to the transverse cross member, wherein the transverse cross member defines an axis about which the seating assembly pivots.

The seat assembly may comprise a seat portion. The seat assembly may comprise a backrest portion. The backrest portion imay be slidably connected to the seat portion such that the depth of the seat portion is adjustable.

The backrest portion may include an attachment member comprising a bulbous profile at its base, wherein the bulbous profile is defined by a shaped void that extends rearwards, down and returns forward, wherein the void is dimensioned to accommodate a length or the seat portion during adjustment of seat depth, wherein the attachment member terminates with a substantially straight section, wherein the substantially straight section facilitates connection of the backrest portion relative to the seat portion and wherein the substantially straight section facilitates displacement of the backrest portion relative to the seat portion. The bulbous profile may be bulbous when viewed from the side of the wheelchair. It will be appreciated that the backrest portion may be formed from or comprise a member of uniform cross-section; such as with a uniform cross-section profile being bent or curved to define the bulbous form.

The substantially straight section may be received in the rear of the seat portion and is operable to slide, guided by and relative to the seat portion to adjust the depth of the seat portion.

The backrest portion may comprise at least one height adjustable back-support component, wherein the at least one height adjustable back-support component is movable relative to the seat portion to adjust the extent of back support.

The combined adjustment of the depth of the seat portion and the height of the backrest portion provides a wheelchair suitable for use by a range of users, for example users of different heights, such as a small child and a tall adult.

The wheelchair may comprise a leg support, which is pivotally connected to the chassis or the seat assembly, wherein the leg support is pivotal relative to a leading edge of the seat assembly and the transverse cross member.

The leg support may be may be dimensioned to fit between the side members of the chassis such that the leg support is pivotal between an extended and retracted configuration;

wherein the extended configuration is where the leg support extends forward of the chassis wherein a lower edge of the leg support is located forward of the leading edge of the seat portion; and

the retracted configuration is where the leg support extends towards the rear of the chassis, wherein the lower edge of the leg support is located between the side members and rearward of the leading edge of the seat portion.

It will be appreciated that the leading edge of the seat portion may comprise the leading edge of the seat assembly.

The leg support may be pivotally dependent on the seat portion, wherein reclining the seat portion causes the leg support to extend forward of the chassis. In addition, the leg support may be pivotally independent of the chassis, wherein the leg support is operable to pivot towards the rear of the chassis independent of the position of the seat portion. The pivotally independent relationship of the leg support and the seat portion may require the seat portion to be in an upright configuration, wherein the upright configuration is where the seat portion is oriented between a forward incline and substantially horizontal orientation.

It will be appreciated, the upright configuration may make it easier for a user to embark and/or disembark from the wheelchair.

The leg support may be pivotally connected to the leading edge of the seat portion or to the transverse cross member, wherein the leading edge of the seat portion or the transverse cross member define an axis of rotation. The axis of rotation may comprise a horizontal axis of rotation.

The leg support may comprise an upper support member and a lower support member, wherein the lower support member is configured to move relative to the upper support member to adjust the length of the leg support. The leg support may comprise a foot rest, wherein the foot rest is connected to or forms part of the lower support member. The lower support member may slidably engage with the upper support member to adjust the length of the leg support.

The leg support may comprise an actuation member operable to lock the leg support against pivotal movement and operable to release the leg support for retraction rearwards relative to the chassis.

The leg support may be narrower than a gap between the front wheels such that it may pass between the wheels during retraction.

The leg support may be pivotable to retract into the void or open space beneath the seat portion.

The leg support may be configured to support both legs of a user.

The wheelchair may comprise arm rests pivotally connected towards the rear of the seat portion. By providing the arm rests on the seat portion, the affect of adjusting the seat depth or backrest height has no affect on the arm rest orientation or position relative to a user sitting on the seat assembly position.

The rear wheels may include a diameter substantially equal to or less than the height of the seat, when the seat is in the upright configuration. Restricting the size of the rear wheels facilitates parallel transfer of a user to and from a wheelchair from and to an adjacent surface. It will be appreciated that the diameter may comprise a maximum diameter of the rear wheel, such that the rear wheels may comprise a maximum diameter that is equal to or less than the height of the seat portion, when the seat is in the upright configuration. The backrest portion may comprise one or more back support components, wherein one or more of the back support components are height adjustable relative to the seat portion and in use relative to a user's back and head.

The backrest portion may comprise at least a head support portion and a lumbar support portion, wherein the head support portion includes a handle configured for assisted propulsion of the wheelchair.

The wheelchair may comprise a flotation aid configured to overlay the seat assembly.

The flotation aid may comprise buoyancy elements distributed about it's perimeter, wherein the buoyancy elements are configured, in use to raise the flotation aid and user from the seat assembly, when the wheelchair is immersed in a body of water.

The flotation aid may comprise full body support element and additional support for a user's head.

The flotation aid may comprise sling attachment points thereby facilitating lifting a user from the wheelchair outside a body of water.

One or more of the front wheels may comprise a forward facing projection operable to engage with a stop provided on or associated with a surface upon which the wheelchair is supported, such that engagement of the forward facing projection and the stop prevents rolling of the wheelchair.

The wheelchair may comprise a releasable fastener connecting the side members and the transverse cross member, such that the side members and the transverse cross member are releasably connected to collapse the chassis to a suitable size for storage or transportation. The releasable fastener may provide a pivotal connection such that upon release of the fastener one or both side members are pivotal relative to the transverse cross member.

The side members may be disconnectable from the transverse cross member to collapse the chassis to a suitable size for storage or transportation.

Each side member may comprise a substantially straight portion defining the rear of the chassis and a curved portion defining the front of the chassis.

The present invention may provide a modular and adjustable wheelchair configured for use by a range of users of various sizes and proportions and for users with restricted mobility and/or various forms of disability.

According to a further aspect, there is provided a floatation aid for a wheelchair.

According to a further aspect, there is provided a leg support for a wheelchair. According to a further aspect, there is provided a method of adapting or modifying a wheelchair. The method may comprise configuring a wheelchair for use with a swimming pool lift, such as a Poolpod™ swimming pool lift available from the Applicant on the priority and/or filing date of this application, such as described in patent application WO2012164290, the contents of which are hereby incorporated herein.

The invention may include one or more corresponding aspects, embodiments or features in isolation or in various combinations whether or not specifically stated (including claimed) in that combination or in isolation. For example, it will readily be appreciated that features recited as optional with respect to one aspect, example, embodiment or claim may be additionally applicable with respect to another aspect, example, embodiment or claim, without the need to explicitly and unnecessarily list those various combinations and permutations here (e.g. the apparatus of one aspect may comprise features of any other aspect). Optional features as recited in respect of a method may be additionally applicable to an apparatus or device; and vice versa. For example, an apparatus may be configured to perform a feature of a method of any other aspect, example, embodiment or claim. In addition, corresponding means for performing one or more of the discussed functions are also within the present disclosure.

DESCRIPTION OF THE DRAWINGS

Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which:

Figure 1 shows a schematic representation of a wheelchair according to embodiments of the present invention;

Figure 2A and 2B shows a schematic representation of the wheelchair configured to support users of different size;

Figure 3 shows a schematic representation of a chassis of the wheelchair illustrated in figures 1 , 2A and 2B;

Figure 4 shows a schematic representation of the chassis of figure 3 comprising a support for a seat assembly;

Figures 5A and 5B show a schematic representation of a seat and backrest of a wheelchair and illustrates how the seating area is adjusted by moving the backrest relative to the seat assembly;

Figures 6 and 7 show the wheelchair of figures 1 , 2A and 2B in an upright configuration to enable parallel transfer; Figures 8, 9A and 9B show a schematic representation of the wheelchair with the leg support in a retracted configuration;

Figure 10 shows a schematic representation of mechanism controlling displacement of the leg support;

Figures 1 1 , 12 and 13 show a schematic representation of the adjustable height of the leg support;

Figures 14 and 15 show a schematic representation of the assembly of the backrest assembly;

Figures 16 to 19 show a schematic representation of the wheelchair with a flotation aid; Figures 20 to 23 show a schematic representation of the wheelchair of figures 1 to 19 in use with a lavatory bowl; and

Figures 24 to 26 show a schematic representation of the wheelchair including a castor arrangement acting as a stop for the wheelchair;

DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Referring to Figure 1 , there is illustrated a perspective view of an adjustable wheelchair 10 suitable to accommodate children and adults securely and in comfort. Figures 2A and 2B illustrate a comparison of the wheelchair 10 being used by a child (figure 2A) and by an adult (figure 2B). The adjustment of the wheelchair 10 to accommodate different sized users is described further below with reference to figures 2A, 2B and figures 14 and 15.

The wheelchair 10 includes a chassis 12 (discussed further below with reference to figure 3), a seat assembly 14, a backrest assembly 16 (discussed further below with reference to figures 14 and 15), a leg support 18 (discussed further below with reference to figures 1 1 , 12 and 13), arm rests 20 (discussed further below with reference to figures 1 to 8), two rear wheels 22, which can be used to self-propel the wheelchair 10 and two castor type front wheels 24.

Referring to figure 3, the chassis 10 provides a construction of minimal structural elements and simplifies the configuration of a wheelchair thereby providing a more versatile wheelchair of reduced weight and less complexity compared with typical wheelchair construction.

The chassis 12 includes two side members 30, 32 and a cross-member 34, which extends between the two side members 30, 32. The transverse cross member 34 is fixed at each end to the side members 30, 32. The location of the transverse cross member is towards the top of the chassis 12 and forward of the rear wheels 22.

In the illustrated example, each side member 30, 32 is a unitary piece of tubular metal, which includes a substantially straight portion 36R, 36L and a curved portion 38R, 38L.

The substantially straight portion 36R, 36L defines the rear of the chassis 12, where a large rear wheel 22R, 22L is attached to the end of a corresponding straight portion 36R, 36L and to the outside face of each side member 12, 14.

The curved portion 38R, 38L defines the front of the chassis 12, where a small articulated wheel 24R, 24L is attached to each end of the curved portion 38R, 38L.

In the illustrated example, the side members 30, 32 and the transverse cross member 34 are releasably connected such that the side members 30, 32 can be disconnected from the transverse cross member 34, or at least pivoted relative to the transverse cross member 34, to collapse the chassis 12 to a suitable size for storage or transportation.

In the illustrated example a bracket 40R, 40L facilitates attachment of the transverse cross member 34 to the side members 30, 32 and release of the transverse cross member 34 from one or both side members 30, 32 to allow the chassis 12 to be collapsed for storage and transportation.

As shown here, each side of the wheelchair 10 comprises a single side member 30, 32 positioned towards each respective side of the wheelchair 10: a single left side member 32 and a single right side member 30. Each side member 30, 32 connects the respective front wheel 24R, 24L to the respective rear wheel 22R, 22L on the associated side of the wheelchair 10. The top of each side member 30, 32 is defined by an intermediate portion of the side member 30, 32. As shown here, the top of each side member 30, 32 is positioned at a height above the front wheel 24R, 24L. The top of each side member 30, 32 corresponds to a user-related height, such as corresponding to a height or position of a knee joint of a user when located in or on the wheelchair 10.

When the wheelchair 10 is viewed from the side (e.g. Figures 2A, 2B), each side member 30, 32 defines an A-shape. The front portion of each side member 30, 32 defines a fore lowermost point of the side member 30, 32. The rear portion of the side member 30, 32 defines a rear lowermost point of the side member 30, 32. The top of the side member 30, 32 is defined by an apex, such as when viewed from the side. The apex comprises the intermediate portion of the side member 30, 32, between the front and rear portions of the side member 30, 32. The fore lowermost point of the front portion of the side member 30, 32 is lower than the rear lowermost point of the rear portion of the side member 30, 32, such as here where the rear wheel 22R, 22L comprises a higher pivot axis than the front wheel 24R, 24L (e.g. here where the rear wheel 22R, 22L has a larger diameter than the front wheel 24R, 24L). The apex of the side member 30, 32 is at or of a similar height to the leading edge of the seat assembly 14 and of the knee-joint of the user.

The front portion extends from the apex downwards to the front wheel 24R, 24L. The front portion is inclined at an angle from horizontal of greater than 75 degrees, being vertical or near-vertical as shown here. Accordingly, the top of the side member is located towards a forward part of the side member 30, 32 (e.g. towards the front end of the wheelchair 10).

The transverse cross member 34 is positioned at a height proximal to or corresponding to the leading edge - at least at or towards a central portion of the transverse member 34, such as at or towards a laterally central portion of the wheelchair 10 (e.g. between or equidistant the side members 30, 32). Accordingly, at least the chassis 12, here the wheelchair 10 as such, comprises or defines a void or open space beneath the seat assembly 14 - at least at or towards the front or a front half of the wheelchair 10. The void or open space is free from obstruction between the ground and the transverse member 32 and between the ground and the seat assembly 14. Here, the transverse member 34 is positioned at a single height, extending horizontally between the side members 30, 32. Figure 3 illustrates a braking mechanism 42, comprising a brake member 44 and a control lever 46, mounted on the outside face of each side member 30, 32 and situated adjacent to each rear wheel 22R, 22L such that the control lever 46 is within easy reach of the user of the wheelchair 10 or of the helper assisting the user and the brake member 44 is located to engage and disengage with the surface of the wheel 22R, 22L.

In figure 1 , the braking mechanism (not visible) is concealed by a cover 48 comprising an aperture or slot 49 through which the lever 46 extends to be accessible to the user or a person assisting the user. It will be appreciated, the cover 48 is located over the braking mechanism 42 to prevent contact between the user of the wheelchair 10 and the braking mechanism 42 and therefore helps to reduce the risk of injury to the user or a person assisting the user. Additionally, the cover 48 protects the braking mechanism and therefore eases maintenance and cleaning.

In the following, the versatility of the wheelchair 10 for use by users of various sizes and by users with different physical needs is demonstrated by describing and illustrating the function and arrangement of the seat assembly 14, the backrest assembly 16, the leg support 18, etc. to provide the wheelchair 10.

Referring to figure 4, a seat plate 60 is mounted on the chassis 12 relative to the transverse cross member 34 such that the seat plate 60 is pivotal relative to the transverse cross member 34. In the illustrated example, the transverse cross member 34 defines the axis of rotation of the seat plate 60 and the leg support 18 (as described further below).

The seat plate 60 is sized to be received between the two side members 30, 32 such that the seat (when assembled) can be tilted for security and comfort of the user and for ease of entering and exiting the wheelchair 10.

In the illustrated example, figure 4 includes a lever mechanism 62 mounted relative to the transverse cross member 34. The lever mechanism 62 is operable to lock and release the seat plate relative to the transverse cross member 34 and the side members 30, 32.

Figure 4 also illustrates a fastener 64, which locks against an attachment member (see figure 5A and 5B) supporting the backrest assembly 16, when the backrest assembly 16 is mounted on the wheelchair 10. The arrangement of the backrest assembly 16 and the seat assembly 14 is described further below.

Referring to figures 2A and 2B the versatility of the wheelchair 10 is demonstrated by a child user in figure 2A and an adult user in figure 2B. Figure 5A and 5B illustrates, schematically an arrangement of a seat assembly 14 and a backrest assembly 16 and how the backrest assembly 16 moves relative to the seat assembly 14 to adjust the seating area to accommodate smaller users and larger users, for example a child and an adult as represented in figures 2A and 2B.

In the illustrated example (figure 5A) an attachment member 70 is provided on both sides of the backrest assembly 16. Each attachment member 70 includes a vertical section 71 , which includes at its base a bulbous profile in the form of a curved portion 72 that extends rearwards, down and returns forward towards the front face of the backrest assembly 16 and terminates with a substantially straight section 74, which is received in slots (not visible in figure 5A) provided through the rear of the seat assembly 14.

The backrest assembly 16 is attached to the seat assembly 14 by inserting the substantially straight section 74 into the slots at the rear of the seat assembly 14 thereby connecting the backrest assembly 16 to the seat assembly 14.

To change the depth of the seat, the backrest assembly 16 is moved forwards or rearwards in the direction of arrows 14A, 14B relative to the seat assembly 14 via the substantially straight section 74 moving in the slot provided in the seat assembly 14. In figure 5, the maximum forward position 14A of the backrest assembly 16 is shown as a dotted outline of the backrest assembly 16 and represents the configuration to accommodate a small adult or child as illustrated in Figure 2A. The maximum rearward position 14B of the backrest assembly 16 is also illustrated in figure 5 as a solid outline and represents the configuration to accommodate a larger adult as illustrated in figure 2B. Figure 5B illustrates a wheelchair 10 (wheels omitted for clarity) which includes an alternative configuration of a backrest 16 compared with figure 5A. In figure 5B the backrest 16 is pivotally adjustable about pivot point 73 provided at the junction of the vertical portion 71 and the substantially straight section 74. It will be appreciated that the backrest 16 illustrated in figure 5B can be reclined independent of the recline angle of the seat portion.

Regarding figures 5A and 5B, it will be appreciated, the position of the backrest assembly 16 can be adjusted from the maximum forwards position to the maximum rearward position as indicated by arrows 14A and 14B. As noted above, with reference to figure 4, a fastener 64 is located on the side of the seat assembly 14. The fastener 64 acts as a lock against the straight section 74 of the attachment member 70 to prevent the backrest assembly 16 moving when supporting a user.

The fastener 64 can be a screw attachment or spring loaded and acts to clamp against the straight section 74 to prevent movement and of the backrest assembly until adjustment is required.

It will be appreciated, a catch, a pin or other suitable device that is configured to connect with the substantially straight section 74 via access through the seat assembly 14 can be used to prevent movement of the backrest assembly 16 relative to the seat assembly 14.

Figures 1 , 2A and 2B each illustrate the wheelchair 10 with the seat assembly and the back assembly in a reclined position. Where the seat assembly is pivoted clockwise relative to the transverse cross member 34, which results in the backrest assembly reclining rearwards.

Also, being able to reclined the seat of the wheelchair whilst occupied by a user can improve comfort and stability of the user and can have positive health effects on the user such as improving circulation or relieving bed sores.

The wheelchair 10 is reconfigurable between the reclined configuration illustrated in figures 1 , 2A and 2B and the upright configuration as illustrated in figure 6 and 7.

The upright configuration is where the seat of the wheelchair 10 is at least horizontal or is reclined forwards to make it easier for a user to sit on or leave the seat. By referring to figures 6 and 7, it will be appreciated that the outside diameter of the rear wheels 22R, 22L is such that the top of the wheel does not obstruct side movement from the seat. As such, parallel transfer from the wheelchair 10 to another surface of similar height is enabled when the seat assembly and the backrest assembly are oriented in the upright configuration.

As described above, the fastener 64 is located on the side of the seat assembly 14 to allow seat depth adjustment. The location of the fastener means that transference of the occupant 80 of the wheelchair to/from the wheelchair from/to a neighbouring surface is free from obstruction and therefore facilitates a parallel transfer as illustrated in figure 7.

Figures 1 , 2A, 2B, 6 and 7 include a leg support 18 extending down from the leading edge of the seat assembly 14.

In the illustrated examples, the leg support 18 is pivotally dependent on the seat assembly 14 when the seat assembly 14 is moving between the upright position and the reclined position i.e. the inclination of the leg support 18 is determined by the inclination of the seat assembly 14. However, the leg support 18 is also pivotally independent of the seat assembly as illustrated in figures 8, 9A, 9B and 10, when the seat assembly 14 is in the upright position to aid embarking and disembarking the wheelchair 10.

Figure 8 shows the wheelchair 10 in an upright configuration and the leg support 18 pivoted rearwards (in the direction of arrow 18A) such that the leg support 18 is located behind the front wheels 24R, 24L. As shown here, the leg support is pivotable to retract into the void or open space beneath the seat assembly 14, passing directly between the front wheels 24R, 24L.

Figure 9A illustrates a user 80 in a "ready for sitting" state and indicates the centre of gravity moving over and towards the seat assembly 14 (schematically illustrated) as the user's bottom moves towards the seating surface 84 of the seat assembly 14.

Figures 9A and 9B illustrate the leg support 18 in a pivotally retracted position, where the leg support 18 and the footrest 19 are pivoted backwards about a transverse axis. The transverse axis may be provided by the transverse cross member 34 or the leading edge of the seat assembly 14. In this position, the leg support 18 and the footrest 19 are moved between the front wheels (omitted for clarity) and come to rest behind the front/leading edge of the seat assembly 14 as indicated by line 86. By moving the leg support 18 and the footrest 19 to this position the user 80 can position his/her feet and legs close to the wheelchair 10 (schematically illustrated), for example such that his/her knee joint 88 is proximate or touching the leading edge of the seat assembly 14 and at least the heel area of his/her feet can be located in the space between the front wheels in an area below the leading edge of the seat assembly 14.

Figure 10 illustrates the chassis 12, where the leg support 18 is suspended from a guide block 90, which forms part of the seat plate 60 (see figure 4). A release member 92 slides sideways to release the leg support 18 such that the leg support pivots backwards towards the rear of the chassis 12. In the illustrated example, the leg support 18 is pivotally attached to the seat plate 60 via the guide block 90, but it will be appreciated the leg support 18 could be pivotally attached to the transverse cross member 34.

The release member 92 may include a spring return mechanism, which means that the user can apply minimal force on the release member 92, for example, by applying a pushing action against the release member 92, such that the leg support 18 is released and moved to the rearward position illustrated in figure 9A and 9B.

A catch (not illustrated) may be provided to retain the leg support 18 in the rearward position (as illustrated in Figures 9A and 9B) until the user 80 is seated. The catch may be releasable such that when the user is seated the leg support 18 can return, under the action of the spring return mechanism, to the forward position indicated in figures 6 and 7.

In the example illustrated in Figures 1 , 2A, 2B, 6 to 8, 1 1 and 12 the leg support 18 is provided by an assembly of a lower leg support member 100 and an upper leg support member 102. The lower leg support member 100 and the upper leg support member 102 are connected via a leg support connector 104, which allows telescopic extension and retraction of the leg support 18, where the lower leg support member 100 moves in the direction of arrow 100A relative to the upper leg support member 102, to increase and decrease the length of the leg support 18.

A guide slot 106 is provided in the lower support member 100, which facilitates telescopic retraction and extension of the leg support 18 via the lower support member 100 sliding relative to the upper support member 102 as guided by the connector 104 which is received in the slot 106.

Referring to figure 13, an articulation member 108 is connected at one end to the leg support 18 (schematically illustrated) and at the other end to the seat assembly 14. In the example illustrated, the articulation member 108 is telescopic and pivotally connected relative to the seat assembly 14 and the leg support 18 such that the ends of the articulation member 108 can be linearly and angularly displaced relative to each other when adjusting the tilt of the seat assembly 14, the backrest assembly 16 and leg support 18. The length of the articulation member 108 can be fixed to prevent rotation of the leg support 18 relative to the seat assembly 14 and the length of the articulation member 108 can be increased or decreased to adjust the angle between the leg support 18 and the seat assembly 14.

An alternative construction to that described above is where the articulation member 108 connects the leg support 18 to at least one of the side members 30, 32 such that rotation of the leg support 18 is relative to the side members 30, 32. The articulation member 108 may incorporate a spring (not illustrated) such that the leg support 18 returns to the forward/deployed position from the rearward/retracted position.

Figures 1 , 2A, 2B, 6, 7, 8, 11 , 12 and 14 illustrate an example of a backrest assembly 16, which is connected to the seat assembly 14 in the manner described above with reference to figure 5.

Figures 1 , 2A, 2B, 6, 7, 8, 1 1 and 12 illustrate the backrest assembly 16 being formed with three back-support components 200, 202, 204. Each component supports a region of the back, for example a pelvic and lumbar support 200, a thoracic support 202 and a cervical and head support 204. The back-support components 200, 202, 204 are each connected to an attachment member 206, to form the backrest assembly 16. The attachment member 206 facilitates connection of backrest assembly 16 to the seat assembly 14 as described above with reference to figure 5.

Figure 14 illustrates connection of a cervical and head support 204 to the attachment member 206.

The attachment member 206 illustrated in figures 1 , 2A, 2B, 6, 7, 8, 11 , 12 and 14 includes a substantially vertical elongate member 208 which extends upwards from a curved portion 210 which terminates with a substantially horizontal straight section 212. As described with reference to figure 5, the curved portion 210 extends from the substantially vertical elongate member 208, rearwards, downwards and returns forward towards the front face of the backrest assembly 16 and terminates with a substantially straight section 212, which is received in slots (not visible in figures 1 , 2A, 2B, 6, 7, 8, 1 1 , 12 and 14) provided through the rear of the seat assembly 14. The configuration of the curved section and the substantially straight section 214 facilitates increasing and decreasing the depth of the seating area such that the wheelchair 10 is suitable for use by different sized users.

The back-support components 200, 202, 204 are each connected to the vertical elongate member 208 and are arranged such the height of each back-support components 200, 202, 204 can be changed, by moving the back-support components in the direction of arrows 208A to suit different sized users.

In the illustrated examples, the attachment member 208 is formed from hollow elongate material to provide strength and to maintain the weight of the wheelchair assembly as lightweight as possible.

Figure 14 illustrates the connection of a cervical and head support 204 to the attachment member 208. In the illustrated example, the cervical and head support 204 is connected to the attachment member 206 via a releasable locking member 214. The releasable locking member 214 allows adjustment of the vertical position of the cervical and head support 204 relative to the attachment member 206, when tightened the releasable locking member 214 locks the cervical and head support 204 to prevent movement and when released the releasable locking member 214 permits removal of the cervical and head support 204 from the attachment member 206. The releasable locking member 214 is in the form of a clamp, that clamps against the substantially vertical elongate member 208 of the attachment

member206 to prevent movement of the cervical and head support 204 unless the releasable locking member 214 is released.

In the illustrated example, the front facing surface 216 of the cervical and head support 204 is padded for comfort and the rear facing surface 218 includes one or more restraint connection points 220 and a handle 222. The restraint connection points 220 facilitate connection of restraints to restrain the occupant of the wheelchair 10 if required.

In the illustrated example, the handle 221 can be used by an attendant to push the wheelchair 10. The handle 221 is oriented such that it is horizontal and at a height which is comfortable to use even if the backrest assembly 16 is tilted.

Referring to figures 1 , 2A, 2B, 6, 7, 8, 1 1 and 12, the lumbar support 200 and the thoracic support 202 are mounted on the substantially vertical elongate member 208 of the attachment member 206 in a similar way as the cervical head support 204 as described above with reference to figure 14.

In the illustrated example, the thoracic support 202 includes a handle 223 which facilitates ease of control of the wheelchair by attendants of different heights and can assist in hand placement to support the wheelchair 10 if tilting the wheelchair 10 onto the rear wheels 22R, 22L when the wheelchair 10 is occupied.

By providing a handle 221 , 223 on both the thoracic support 202 and the cervical and head support 204 regulatory controls of handle placement for assisted use are met because the ability to adjust the height of the support components 202, 204 provides a height window within which one or more of the handles 221 , 223 will be located depending on the location of the support component 202, 204 relative to the seat assembly 14.

Figure 6 and 15 illustrate the wheelchair 10 comprising the backrest assembly 16 and the seat assembly 14. Figure 6 shows compartments 222 located in the front face of the back- support components 200, 202, 204 and a compartment 224 located in the seat assembly 14. Figure 15 illustrates concealment of the compartments 222,224 by adding a cushion 226, 228 to each of the back-support components 200, 202, 204 and to the seat assembly 14. In the illustrated example, the cushions 226, 228 are attached, for quick release, with hook and loop fastening (Velcro®) to the front facing surface of the back-support components 200, 202, 204 and the upper surface of the seat assembly 14. The cushions 226, 228 provide comfort to the user and double as covers operable to conceal restraints, for example straps that can be used to secure a user in the wheelchair if required.

In the illustrated example, restraints 230 are stored in the compartments 222,224, such that when the cushion 226, 228 is peeled away from one or more of the back-support

components 200, 202, 204 or the seat assembly 14 the restraints 230 can be accessed. It will be appreciated, the cushions 226, 228 may include slots (not shown) through which the restraints 230 can extend if restraining the occupant is required. Otherwise, the restraints can remain concealed behind the cushion 226, 228.

As described above, the purpose of the illustrated wheelchair 10 is to accommodate users of different sizes and different needs. For example, one user may have negligible mobility and therefore requires to be restrained whilst sitting in the wheelchair and another user may be slightly immobile, for example poor leg mobility. Figures 1 , 2A, 2B, 6, 7, 8, 11 and 12 illustrate a wheelchair 10 that is adaptable to suit either user-type. In this regard, Figures 6 and 15 illustrate how multiple restraint points can be provided, but also demonstrates that each restraint point is concealable, for example behind and under cushions attachable to the front facing surface of the seat assembly 14 and the back-support components 200, 202, 204.

Figures 16, 17, 18, and 19 illustrate to a further adaptation of the wheelchair 10 of the described above with reference to figures 1 to 15. In figures 16, 17, 18, 19A and 19B the wheelchair 10 includes a flotation aid 300 as part of the seat assembly 14. The flotation aid

300 facilitates transferring a user from the wheelchair 10 into a body of water, for example a swimming pool, when the wheelchair 10 and user are at least partially immersed in the body of water.

In the illustrated example, the flotation aid 300 is installed as an overlay of the seat assembly 14 before the user sits in the wheelchair 10.

When the wheelchair 10 is lowered into the body of water the flotation aid 300 becomes buoyant and gently and securely lifts the disabled person away from the seat assembly, as illustrated in figures 18 and 19.

To maximise the stability of the user on the flotation aid 300 buoyancy elements 310 are distributed about the perimeter of the flotation aid 300. The flotation aid 300 includes a back-support element 316, a bottom support element 314 and a leg support element 318. These elements 314, 316, 318 are configured to overlay the corresponding part 14, 16, 18 of the wheelchair 10. A cushioned section 320 is provided to support the user's head.

The flotation aid 300 may also include a sling function (not illustrated) where the flotation aid includes attachment points for sling hooks to lift and lower a user from the wheelchair 10.

A warm water environment often promotes therapeutic benefits. Therefore, the flotation aid 300 can include heat storage and/or heat emitting and insulating members or materials (not illustrated.

Referring to figures 20, 21 and 22, the wheelchair 10 (schematically illustrated) is configured for use with a lavatory bowl 352. In the illustrated example, the seat assembly 14

(schematically illustrated) includes a hole 350 proximate the centre of the seat assembly 14 to allow the user to use the lavatory when the wheelchair 10 is situated over the lavatory bowl 352 (see figure 22).

In the illustrated example, the configuration of the chassis 12 (schematically illustrated) is such that a transverse member/transverse cross member 34 is located forward and high on the side members 30, 32. As such, a wheelchair 10 constructed on chassis 12 can be positioned over a lavatory bowl 352 such that the user does not need to transfer from the wheelchair 10 to the lavatory bowl 352. In this example of use, a modular seat assembly could be used with the chassis 12; i.e. a seat assembly including a seat pad with a hole 350 through it.

As described above with reference to figures 1 , 2A, 2B, 6, 7, 8, 11 and 12 the seat assembly 14 is attached the chassis 12 relative to the cross-member 34 such that it can tilt forwards for ease of exit from the seat 14 and it can tilt rearwards to adopt a reclined position. It will be appreciated that even a slight recline can impart a feeling of security for the user because a feeling that they may fall or be ejected from the wheelchair is reduced.

Figures 20, 21 and 22 illustrate the placement of the wheelchair 10 relative to a lavatory bowl 352, wherein the angle of inclination of the seat assembly 14 can be adjusted to accommodate the lavatory bowl 352 beneath the seat assembly 14 and between the side members 30, 32

Figures 21 and 22 illustrates the degree of articulation of the seat assembly 14, the backrest assembly 16 and the leg support 18 relative to the lavatory bowl 352.

In the illustrated example, the seat assembly 14, the backrest assembly 16 and the leg support 18 are adjusted to the upright position, where the seat assembly is substantially horizontal (see figures 21 and 22), the backrest assembly 16 is substantially vertical and the leg support 18 is inclined forwards. Once the wheelchair 10 is positioned over the lavatory bowl 352, as illustrated in figure 22, the position of the seat assembly 14 can be

adjusted/tilted relative to the lavatory bowl 352 for the ease and comfort of the user.

The pivotal arrangement of the leg support 18 prevents obstruction when the wheelchair 10 is situated relative to the lavatory bowl 352 (see figure 22).

Figures 21 and 22 illustrate the arrangement of the leg support 18 and the footrest 19 when the wheelchair 10 is positioned over a lavatory bowl 352. In this example, the leg support 18 is inclined forwards such that it does not obstruct positioning the wheelchair 10 over the lavatory bowl 352.

Figure 23 illustrates an example of a wheelchair 10 similar to figures 20, 21 and 22, but where the wheelchair 10 does not include a leg support.

Referring to figures 1 , 6, 7, 8, 11 , 12 and 16, the wheelchair 10 includes arm rests 20. In the illustrated example, the arm rests 20 are pivotally attached to the rear of the seat assembly 14 such that they can be pivoted rearwards (towards the backrest 16) to allow parallel transfer to and from the wheelchair 10, as illustrated in figure 7. By attaching the armrest 20 to the seat assembly 14 the position of the armrests 20 is not affected when the backrest 16 is moved relative to the seat assembly 14 to adjust the depth of the seat as described above.

In the illustrated example, the armrests 20 include a solid surface and provide side support and containment for the user when seated in the wheelchair 10.

In each of the examples described above the seat assembly 14, backrest assembly 16 and leg support 18 can be tilted relative to the chassis 12. To tilt the seat assembly 14, the wheelchair 10 includes an actuating mechanism (not illustrated). The actuating mechanism may be provided by a lead screw, or a linear actuator or strut connected to the seat 14 and to the chassis 12. The actuating mechanism may be located to the rear of the wheelchair 10, attached to the seat assembly 14 and to the side members 30, 32 such that adjustment of the actuating mechanism cause angular displacement of the seat assembly 14, backrest assembly 16 and leg support 18 relative to the chassis 12.

Referring to figures 24 to 26, the wheelchair 10 (schematically illustrated) includes a castor wheel assembly 400, which includes a castor wheel 402 configured to pivot about a vertical axis (arrow 404) to control steering of the wheelchair 10 by permitting displacement the rotational axis of the castor wheel 402. In the illustrated example, the castor wheel 402 is permitted to rotated by approximately 90 degrees such that the face of the wheel 402 aligns with a forward-facing projection 406. Whilst the castor wheel 402 is oriented in this way, the forward-facing projection 406 is configured to interact with a barrier 408 on the surface (see figures 25 to 26), for example, by a poolside, in a vehicle, on a boat, on a platform lift etc. upon which the wheelchair 10 is received and upon which further movement of the wheelchair 10 is to be prevented.

Other examples of displacing the castor wheel 402 relative to an engagement member or lip, provided on a support surface, are illustrated in figures 25 to 26, where the orientation of the castor wheel 402 permits interaction between a projection 406 on the wheelchair 10 and an engagement member or barrier 408 to prevent the wheelchair 10 from moving. Figure 26 two variants of castor assembly 400, where each has a projection element 406 at different heights.

Whilst specific embodiments of the present invention have been described above, it will be appreciated that departures from the described embodiments may still fall within the scope of the present invention.

It will be appreciated that any of the aforementioned apparatus may have other functions in addition to the mentioned functions, and that these functions may be performed by the same apparatus.

The applicant hereby discloses in isolation each individual feature described herein and any combination of two or more such features, to the extent that such features or combinations are capable of being carried out based on the present specification as a whole in the light of the common general knowledge of a person skilled in the art, irrespective of whether such features or combinations of features solve any problems disclosed herein, and without limitation to the scope of the claims.

The applicant indicates that aspects of the present invention may consist of any such individual feature or combination of features. It should be understood that the embodiments described herein are merely exemplary and that various modifications may be made thereto without departing from the scope or spirit of the invention. For example, it will be appreciated that although shown here with two small front wheels and two large rear wheels, at leat some features and or aspects may be applicable to or suitable for other arrangements or configurations of wheelchairs.

Claims

1. A wheelchair comprising:

a chassis;

front wheels;

rear wheels; and

a seat assembly;

wherein the front wheels, rear wheels and seat assembly are connectable to the chassis; and

wherein the chassis comprises two spaced-apart side members and a transverse cross-member connecting the side members, wherein the transverse cross member is connected to each side member towards the top and towards the front of each side member, and wherein a leading edge of the seat is connected to the chassis proximate the transverse cross member.

2. A wheelchair as claimed in claim 1 , wherein the seat assembly is pivotally connected to the chassis such that it is pivotal relative to the transverse cross member between a rearward inclined configuration and an upright position, wherein the upright position is between substantially horizontal and a forward inclined position.

3. A wheelchair as claimed in claim 1 or 2, wherein the seat assembly is connected at the leading edge to the transverse cross member, wherein the transverse cross member defines an axis about which the seating assembly pivots.

4. A wheelchair as claimed in any preceding claim, wherein the seat assembly comprises a seat portion, and a backrest portion, wherein the backrest portion is slidably connected to the seat portion such that the depth of the seat portion is adjustable.

5. A wheelchair as claimed in claim 4, wherein the backrest portion includes an attachment member comprising a bulbous profile, wherein the bulbous profile is defined by a shaped void that extends rearwards, down and returns forward, wherein the void is dimensioned to accommodate a length or the seat portion during adjustment of seat depth, wherein the attachment member terminates with a substantially straight section, wherein the substantially straight section facilitates connection of the backrest portion relative to the seat portion and wherein the substantially straight section facilitates displacement of the backrest portion relative to the seat portion.

6. A wheelchair as claimed in claim 5, wherein the substantially straight section is received in the rear of the seat portion and is operable to slide, guided by and relative to the seat portion to adjust the depth of the seat portion.

7. A wheelchair as claimed in claim 4, 5 or 6, wherein the backrest portion comprises at least one height adjustable back-support component, wherein the at least one height adjustable back-support component is movable relative to the seat portion to adjust the extent of back support.

8. A wheelchair as claimed in any preceding claim, further comprising a leg support, which is pivotally connected to the chassis or the seat assembly, wherein the leg support is pivotal relative to the leading edge of the seat assembly and the transverse cross member.

9. A wheelchair as claimed in claim 8, wherein the leg support is dimensioned to fit between the side members of the chassis such that the leg support is pivotal between an extended and retracted configuration; wherein the extended configuration is where the leg support extends forward of the chassis and a lower edge of the leg support is located forward of the leading edge of the seat portion; and

the retracted configuration is where the leg support extends towards the rear of the chassis, and the lower edge of the leg support is located between the side members and rearward of the leading edge of the seat portion.

10. A wheelchair as claimed in claim 8 or 9, wherein the leg support is pivotally dependent on the seat portion, wherein reclining the seat portion causes the leg support to extend forward of the chassis.

1 1. A wheelchair as claimed in claim 8, 9 or 10, wherein the leg support is pivotally independent of the chassis, wherein the leg support is operable to pivot towards the rear of the chassis independent of the position of the seat portion.

12. A wheelchair as claimed in claim 12, wherein the pivotally independent relationship of the leg support and the seat portion requires the seat portion to be in an upright

configuration, wherein the upright configuration is where the seat portion is oriented between a forward incline and substantially horizontal orientation.

13. A wheelchair as claimed in any of claims 8 to 12, wherein the leg support is pivotally connected to the leading edge of the seat portion or to the transverse cross member, wherein the leading edge of the seat portion or the transverse cross member define an axis of rotation.

14. A wheelchair as claimed in any of claims 8 to 13, wherein the leg support comprises an upper support member and a lower support member, wherein the lower support member is configured to move relative to the upper support member to adjust the length of the leg support.

15. A wheelchair as claimed in claim 14, wherein the lower support member slidably engages with the upper support member to adjust the length of the leg support.

16. A wheelchair as claimed in claim 14 or 15, further comprising a foot rest connected to or forming part of the lower support member, wherein the foot rest is located at a lower end of the lower support member.

17. A wheelchair as claimed in any of claims 8 to 16, wherein the leg support further comprises an actuation member operable to lock the leg support against pivotal movement and operable to release the leg support for retraction rearwards relative to the chassis.

18. A wheelchair as claimed in any of claims 8 to 17, wherein the leg support is narrower than a gap between the front wheels such that the leg support passes between the wheels during retraction.

19. A wheelchair as claimed in any of claims 8 to 18, wherein the leg support is configured to support both legs.

20. A wheelchair as claimed in any preceding claim, further comprising arm rests pivotally connected towards the rear of a bottom receiving seat portion of the seat assembly, wherein the arms are pivotal about a horizontal axis and in a vertical plane.

21. A wheelchair as claimed in any of claims 4 to 20, wherein the backrest portion comprises one or more back support components, wherein one or more of the back support components are height adjustable relative to the seat portion and in use relative to a user's back and head.

22. A wheelchair as claimed in any of claims 4 to 20, wherein the backrest portion comprises at least a head support portion and a lumbar support portion, wherein the head support portion includes a handle to the rear, wherein the handle is configured for assisted propulsion of the wheelchair.

23. A wheelchair as claimed in any preceding claim, further comprising a flotation aid configured to overlay the seat assembly.

24. A wheelchair as claimed in claim 23, wherein the flotation aid comprise buoyancy elements distributed about the perimeter of the flotation aid and wherein the buoyancy elements are configured, in use to raise the flotation aid and user from the seat assembly, when the wheelchair is immersed in a body of water.

25. A wheelchair as claimed in claim 23 or claim 24, wherein the flotation aid comprises a full body support element and additional support for a user's head.

26. A wheelchair as claimed in claim 23, 24 or 25, wherein the flotation aid further comprises one or more sling attachment points thereby facilitating lifting a user from the wheelchair.

27. A wheelchair as claimed in any preceding claim, wherein one or more of the front wheels comprises a forward facing projection operable to engage with a stop provided on a surface upon which the wheelchair is supported, such that engagement of the forward facing projection and the stop prevents rolling of the wheelchair.

28. A wheelchair as claimed in any preceding claim, further comprising a releasable fastener connecting the side members and the transverse cross member, such that the side members and the transverse cross member are releasably connected to collapse the chassis to a suitable size for storage or transportation.

29. A wheelchair as claimed in claim 28, wherein the releasable fastener provides a pivotal connection such that upon release of the fastener one or both side members are pivotal relative to the transverse cross member.

30. A wheelchair as claimed in claim 28 or 29, wherein the side members are

disconnectable from the transverse cross member to collapse the chassis to a suitable size for storage or transportation.

31. A wheelchair as claimed in any preceding claim, wherein each side member comprises a substantially straight portion defining the rear of the chassis and a curved portion defining the front of the chassis.

32. A wheelchair as claimed in any preceding claim, wherein the rear wheels include a diameter substantially equal to or less than the height of a bottom receiving part of the seat assembly, when the seat assembly is in an upright configuration wherein the upright position is between substantially horizontal and a forward inclined position.