GB2473833A

GB2473833A - A collapsible wheelchair with means to assist in movement over stairs

Info

Publication number: GB2473833A
Application number: GB0916752A
Authority: GB
Inventors: Craig Camidge
Original assignee: Evac and Chair International Ltd
Current assignee: Evac and Chair International Ltd
Priority date: 2009-09-24
Filing date: 2009-09-24
Publication date: 2011-03-30
Also published as: GB0916752D0

Abstract

A wheelchair comprising a collapsible main frame and means 30 to insist in movement over stairs attached to the rear of the frame. Movement of the frame from an operable position to an inoperable one and vice versa automatically moves the stair movement means 30 in the same manner. However, when the frame is in the operable position it may also be possible to move the stair movement means 30 to its inoperable position. The stair movement means 30 may be a flexible track 31 with a region for the track to be displaced into and means to automatically tension the track. Lockable and extendable handles 60 may also be provided. A footrest 17 may be provided with a locking means activated by twisting a handle and featuring an axle with a flexible element. A pivoting seat 14 may be provided with a locking means on its underside. Braking means with a piercing pin may also be used.

Description

Title: A Wheelchair

Description of Invention

This invention relates to a wheelchair. More particularly, but not exclusively, this invention relates to a wheelchair which can also be used to transport/carry person up or down a flight of stairs or steps. For ease of reference, the term "stair(s)" will be used hereinafter to encompass a flight of stairs, steps, or any equivalent thereto.

The invention has been devised for use by medical staff, e.g. paramedics, to assist them in transporting a patient from one location (e.g. the patient's home) to another location (e.g. an ambulance) so that the patient can then be transported to a desired medical facility. The invention has been devised with a view to being used for transporting/carrying bariatric patients (i.e. clinically obese patients), although it will be appreciated that the invention could also be used for non-obese patients.

It is an object of the present invention to provide an improved wheelchair.

According to a first aspect of the invention, we provide a wheelchair having a main frame which is moveable between an operable and an inoperable condition, and vice versa, the wheelchair including at least one stair support assembly pivotally connected to a rear of the main frame, the stair support assembly being pivotally moveable between a stored and a operative condition, wherein, when the main frame is moved from its inoperable condition to its operable condition, the stair support assembly is automatically moved to its operative condition.

Further features of the first aspect of the invention are set forth in claims 2 to 17 appended hereto.

According to a second aspect of the invention, we provide a wheelchair having at least one stair support assembly connected to a rear of a main frame of the wheelchair, the stair support assembly having an endless flexible member which is supported for rotation by a support member which provides at least.

two points of inflexion of the endless flexible member, wherein the support member affords a region into which the endless flexible member is displaceable.

Further features of the second aspect of the invention are set forth in claims 19 to 25 appended hereto.

According to a third aspect of the invention, we provide a wheelchair having at least one stair support assembly connected to a rear of a main frame of the wheelchair, the stair support assembly having an endless flexible member which is supported for rotation by a support member which provides at least two points of inflexion of the endless flexible member, wherein the stair support assembly includes means for automatically tensioning the endless flexible member.

Further features of the third aspect of the invention are set forth in claims 27 to 34 appended hereto.

According to a fourth aspect of the invention, we provide a wheelchair having at least one lifting device for assisting in lifting the wheelchair, the lifting device including a handle which is connected to an elongate member, the elongate member being slidably moveable relative to the main frame between a stored condition and a fully deployed condition, wherein the lifting device includes means for holding the elongate member at any position between the stored and fully deployed conditions.

Further features of the fourth aspect of the invention are set forth in claims 36 to 50 appended hereto.

According to a fifth aspect of the invention, we provide a device for holding a first part of an apparatus relative to a second part of an apparatus, the first part having a holding formation and the second part having a receiving formation, wherein the holding formation is receivable in the receiving formation when the former is oriented in a first orientation relative to the receiving formation, and wherein, when the holding formation is subsequently moved to a second orientation relative to the receiving formation, the receiving formation prevents the holding formation from being withdrawn therefrom.

Further features of the fifth aspect of the invention are set forth in claims 52 to 69 appended hereto.

According to a sixth aspect of the invention, we provide a wheelchair having a first side frame part and a second side frame part, wherein the first and second side frame parts are connected to each other by a flexible element which permits the first and second side frame parts to move relative to each other.

Further features of the sixth aspect of the invention are set forth in claims 71 to 76 appended hereto.

According to a seventh aspect of the invention, we provide a wheelchair having a main frame and a seat, the seat being pivotally connected to the main frame and being pivotally moveable between an operable and an inoperable condition, the wheelchair including a holding device for holding the seat in its operable condition, wherein the holding device includes a first part which is connected to the seat and a second part provided on, connected to or supported by the main frame, wherein when the seat is moved to its operable condition the first part moves under gravity to engage the second part.

Further features of the seventh aspect of the invention are set forth in claims 78 to 90 appended hereto.

According to a eighth aspect of the invention, we provide a braking device for a wheel which is supported for rotation by a wheel axle connected to a body, the braking device including a first part which is rotationally fast relative to the wheel, and a second part connected to the body, the second part including a projecting formation which is moveable to pierce a surface of the first part.

Further features of the eighth aspect of the invention are set forth in claims 92 to 103 appended hereto.

Embodiments of the present invention will now be described by way of examples only with reference to the accompanying drawings, of which:-Figure 1 is a front perspective view of a wheelchair in accordance with the present invention in an operable condition; Figure 2 is a rear perspective view of a wheelchair in accordance with the present invention in an operable condition; Figure 3 is a side view of a wheelchair in accordance with the present invention in an operable condition; Figure 4 is a rear view of a wheelchair in accordance with the present invention in an inoperable condition; Figure 5 is a plan view of a wheelchair in accordance with the present invention in an operable condition; Figure 6 is a front view of a wheelchair in accordance with the present invention in an inoperable condition; Figure 7 is a front perspective view of a wheelchair in accordance with the present invention in an inoperable condition; Figures 8 to 11 show side views of a wheelchair in accordance with the present invention being moved from its operable condition to its inoperable condition; Figures 12 to 14 show side views of a wheelchair in accordance with the present invention with the stair support assembly thereof being moved from its operative condition to its stored condition; Figure 15 is a side cross-sectional view of components parts of the stair support assembly; Figure 16 is a side cross-sectional view of components parts of the stair support assembly; Figure 17 is an exploded perspective view of components parts of the stair support assembly; Figure 18 is a side cross-sectional view of further components parts of the stair support assembly; Figure 19 is an exploded perspective view of the components parts of figure 18; Figure 20 is a side view of a holding device for holding the wheelchair in its operable condition; Figure 21 is a further side view of the holding device; Figure 22 is a side view of the wheelchair with a lifting device thereof in a stored condition; Figure 23 is a side view of the wheelchair with a lifting device thereof in a fully deployed condition; Figure 24 is a side view, with parts cut away, of the wheelchair with a lifting device thereof in a stored condition; Figure 25 is an exploded perspective view of components parts of the lifting device; Figure 26 is a side cross-sectional view of components parts of the lifting device, with an urging member thereof shown in a first position; Figure 27 is a side cross-sectional view of components parts of the lifting device, with an urging member thereof shown in a second position; Figure 28 is an end cross-sectional view of components parts of the lifting device; Figure 29 is a perspective view of a braking device provided for the left side rear wheel of the wheelchair; Figure 30 is a perspective view of a braking device provided for the right side rear wheel of the wheelchair; Figures 31 and 32 are side views of component parts of the braking device in operation; Figure 33 is an exploded perspective view of the braking device shown in figure 29; Figure 34 is a plan view of a footrest of the wheelchair; Figure 35 is a close-up perspective view of component parts of the footrest; Figure 36 is a further close-up perspective view of component parts of the footrest; Figure 37 is a yet further close-up perspective view of component parts of the footrest with a holding formation thereof in a first orientation; and Figure 38 is a yet further close-up perspective view of component parts of the footrest with a holding formation thereof in a second orientation.

Referring to figures 1 to 14, these show a wheelchair 10 in accordance with the present invention. The wheelchair 10 has a main frame 12 constructed from a plurality of frame members (the specific details of which will be discussed later), and a four ground-engaging wheels 18, 20, one positioned, generally, at each corner of the wheelchair 10. The front wheels 18 are castor wheels, which are connected to the main frame 12 such that they are free to swivel about a substantially upright axis. The rear wheels 20 (which are larger in diameter than the wheels 18) are fixed for rotation only about a horizontal axis. The wheelchair 10 also includes a seat 14 which in this example is pivotally connected to the main frame 12. Mounted on a rear and upwardly extending part of the main frame 12 is a backrest 15. Seat 1 4a and back I 5a cushions are provided to improve comfort for the user. The wheelchair 10 also includes a pivotally moveable footrest 17 which can be stored, if desired.

The wheelchair 10 in the present example has been devised for use by medical staff, e.g. paramedics, to assist them in transporting a patient from one location (e.g. the patient's home) to another location (e.g. an ambulance) so that the patient can then be transported to a desired medical facility. The wheelchair 10 of the present example has been devised with a view to being used for transporting/carrying bariatric patients (i.e. clinically obese patients), although it will be appreciated that the invention could also be used for non-obese patients. Thus, the seat is constructed to withstand the loads caused by a person weighing up to 250kg, although it would be possible to increase the structural strength of the wheelchair 10 if it was desired to be able to support patient's weighing in excess of 250kg.

The wheelchair 10 has also been devised to assist not only in transporting a patient along a generally flat surface, but also for transporting/carrying person up or down a flight of stairs or steps. Thus, the wheelchair 10 includes a pair of stair support assemblies 30, which are connected to a rear of the main frame 12. One stair support assembly 30 is provided on one (left) side of the rear of the wheelchair 10 and one stair support assembly 30 is provided on the other (right) side of the rear of the wheelchair 10. The construction and functionality of the stair support assemblies 30 will be discussed later.

The wheelchair 10 is moveable between an operable position (see, for example, figures 1, 2, 3, 5, 12, 13 and 14) and an inoperable or collapsed condition (see, for example, figures 4, 6, 7 and 11). Figures 8, 9 and 10 show side views of the wheelchair 10 as it is progressively moved from its operable condition to its inoperable (or collapsed) condition. It should be noted that the wheelchair 10 has been configured such that when in its inoperable (or collapsed) condition, the width of the wheelchair 10 (when viewed side on -as shown in figure 11) is virtually identical to the diameter to the rear wheel 20. In other words, no components parts of the wheelchair 10 (except for a small portion of the stair support assemblies 30) extend beyond the diameter of the rear wheel 20 in either the forwards or rearwards direction.

In more detail, the main frame 12 has a rear frame part comprised of two upwardly extending tubular frame parts 22 which mirror each other. Each frame part 22 extends from adjacent an axle 108 supporting the rear wheels (to which it is connected by a bracket) upwardly towards the seat 14 where it then extends substantially diagonally outwardly. Each frame part 22 then extends substantially vertically to afford a connection area for the backrest 15 and finally extends substantially horizontally inwardly towards a generally vertical axis of the wheelchair 10. At this point, the frame parts 22 connect to each other.

A support for the backrest 15, which is connected to the frame parts 22, and extends substantially laterally therebetween, supports a hand rail 16, which is substantially U-shaped when viewed from the rear. The hand rail 16 is slidably moveable relative to the main frame 12 so that it can be adjust to best suit a person pushed or pulling the wheelchair 10. It may be desirable for the person to adjust the height of the hand rail 16, depending on whether they are moving the wheelchair 10 along a flat surface or up/down a flight of stairs.

The seat 14 is pivotally connected via an axle 21 to each frame part 22 such that it is pivotally moveable towards and away from the backrest 15. It will be noted from the figures that when the wheelchair 10 is in the inoperable or collapsed condition, a surface of the seat 14 abuts or at least rests close to a surface of the backrest 15.

Connected to each free end of the axle 108, outside each rear wheel 20, is a side frame part 26. Each side frame part 26 extends away from the rear wheel towards a front of the wheelchair 10 where it supports a respective castor wheel 18. The frame part 26 slopes slightly upwardly as it extends towards the front of the wheelchair 10.

Each side of the frame 12 is provided with a further side frame part 26 which is generally straight and pivotally connected at one end to the end of the frame part 26 adjacent the castor wheel 18. An opposite end of the frame part 24 is pivotally connected to an underside of the seat 14. The pivotal connection is substantially midway along a lateral side of the seat 14.

Finally, the main frame 12 includes a central link 88 which extends between the axle 108 and an underside of the seat 14. The link has two parts 89, 90 which are telescopically moveable relative to each other, with the part 89 being slidably received in an elongate cylindrical recess in the part 90. The free end of the link 89 is pivotally connected to the underside of the seat 14 by an axle 82 (see figures 20 and 21) and the free end of the part 90 is pivotally connected at 91 to central region of the axle 108.

The footrest 17 is substantially U-shaped and is pivotally connected at each of its side to and between the frame parts 24. The footrest 17 includes an cross member 17b which extends laterally across the U-shape section to provide supports for the heels of a user's feet, or for the rear of their shoes. When the wheelchair 10 is in its operable condition the footrest 17 extends forwarding and in front of the castor wheels 18.

As shown in figures 34 to 38 the wheelchair 10 includes a device 130 for holding the footrest 17 in its deployed condition. In the present example, this is provided in the form of an axle 136, which is formed from two axle parts 136a, 136b which are connected to each other by a flexible element 150 (discussed later). The axle 136 extends laterally across the main frame 12 and is supports at its opposite ends in apertures in the frame parts 24.

Outermost ends of each axle part 136a, 136b are each provided with a graspable knob or handle 138, which can be used to effect rotation of the axle parts 136a, 136b.

Each free end of the tubular U-shaped footrest section includes a slot 134 which extends diametrically through the tube to just past an axis of the tube.

The slots 134 are positioned such that they receive the axles 136a, 136b which the footrest 17 is in its deployed condition. Each axle 136a, 136b is provided with a disc-shaped formation 132, each of which is positioned such that it is aligned with its respective slot 134. The disc-shaped formations 132 are aligned with each other.

It can been seen from figures 36 and 37 that the disc-shaped formation 132 is receivable in the slot 134 when the disc-shaped formation 132 is oriented in a first orientation relative to the slot 134. In this orientation, it is possible for a user to pivot the footrest 17 to its stored condition, if desired. However, as shown in figure 38, when the disc-shaped formation 132 is rotated to a second orientation (e.g. as a result of the axle 136 being rotated 90° by one of the knobs 138) the slot 134 prevents the disc-shaped formation 132 from being withdrawn therefrom, and thus prevents the footrest 17 from moving to its stored condition. This is because the width (i.e. diameter) of the disc-shaped formation 132 is larger than the width dimension of the slot 134.

To assist a user, an inwardly facing surface of each knob 134 includes a formation 140 to hold the knob 138 in either of two predetermined positions.

The first corresponding to the disc-shaped formation 132 being aligned with and receivable in the slot 134, and the second corresponding to a 90° rotation of the axle 136. The fact that one knob 138 is provided at each side of the wheelchair 10 means that the footrest 17 can be unlocked and moved to its stored condition from either side of the wheelchair 10.

As mentioned above, the axles I 36a, 1 36b are connected to each other by a flexible element 150, which is manufactured from a polyamide material, e.g. Nylon®. This element 150 permits, to some degree, the left and right sides of the wheelchair 10 to move relative to each other. This is beneficial when the wheelchair 10 is being moved over uneven ground. In addition, the flexible element 150 permits the footrest 17 to be unlocked and moved to its stored condition irrespective of whether the from castor wheels 18 are at the same height, e.g. even if they are at different heights because the wheelchair 10 is on uneven ground. Such a flexible element could be utilised in any laterally extending part of wheelchairs which connected left and right sides thereof.

The wheelchair 10 includes a pair of lifting devices 60, one position at each side of the wheelchair 10. The lifting devices 60 are identical in construction and operation, and thus only one of them will be described in detail herein.

The lifting device 60 includes a handle 61 which is connected to one end of an elongate member 62. The elongate member 62 is slidably received in the frame part 26 such that the elongate member 62 is telescopically moveable out from and into the frame part 26, between a stored condition (see figure 22) and a fully deployed condition (see figure 23). The lifting device 60 advantageously includes means for holding the elongate member at any position between the stored and fully deployed conditions. The holding means in the present example (see figures 24 to 28) includes a pair of disc-shaped engaging members 66 which are each configured to engage an internal surface of the frame part 26. The engaging members 66 in this example are made from natural rubber, which provides a good friction with the internal surface of the frame part 26. It should be appreciated, however, that any other suitable material could be used for the engaging members 66.

The engaging members 66 are supported by a sildable body 65 which is sized so that is slides smoothly along the interior of the frame part 26. Upper and lower sides of the slidable body 65 each include a shallow cylindrical recess to receive and support the engaging members 66. The internally facing surface of each engaging member 66 abuts a support part 67 which is also circular in plan view. An internally facing surface of each support part is conically shaped. The slidable body 65 includes a horizontally extending aperture 69 which extends from a front of the slidable body 65 towards a rear thereof. The aperture 69 receives a slidable urging part 70, which is configured to urge the engaging members 66 into engagement with the internal surfaces of the frame part 26. The urging part 70 is frusto-conical in shape and is connected at its rear end to an end of a rod 72. The rod 72 includes a stepped shaft which supports a spring 71. A free end of the rod 72 includes an aperture 73 which provides a connection for a link 75 which extends from the rod 72 to an actuator member or trigger 74 which is pivotally connected to the elongate member 62 adjacent the handle 61.

As can be seen from figures 26 and 27, the spring 71 acts to bias the urging part 70 inwardly towards the engaging members 66. The frusto-conical shape of the urging part 70 and the conical shape of the support parts 67 ensures that movement of the urging part 70 in a first direction towards the engaging members 66, urges the engaging members 66 away therefrom in a direction A which is substantially perpendicular to the direction of travel of the rod 72.

Pivoting movement of the trigger 74 effects linear movement of the rod 72, and the urging part 70, away from the engaging members 66. The trigger 74 can be operated by a digit of a person's hand when that hand is grasping the handle 61, which is highly beneficial. The person lifting the wheelchair 10 can therefore maintain a grip of the handle 61 whilst adjusting the position of the handle 61 relative to the main frame 12.

Providing a lifting device 60 in accordance with the present invention at each side of the wheelchair 10 is highly beneficial, as it permits a person to easily lift a front end of the wheelchair 10. The user can grasp both handles 61 and extend the handle 61 to the desired length at the same time, without having to release either of the handles 61. In addition, the length of extension of the handles 61 can be adjusted to any position between the stored and fully deployed conditions -they are thus infinitely adjustable between the extreme positions. This can be advantageous if, for example, the wheelchair is being carried up or down a non-linear flight of stairs, e.g. a spiral staircase. In this example, the outermost handle 61 can be extended further towards the fully deployed condition than the innermost handle 61, thus rendering it much easier for the person lifting the front end of the wheelchair 10.

As mentioned earlier the wheelchair 10 includes a pair of stair support assemblies 30, one provided on the left rear of the wheelchair 10 and one provided on the right rear of the wheelchair 10. The stair support assemblies are identical in construction and functionality and thus only the left-hand side stair support assembly 30 will be discussed in detail. Each stair support assembly 30 is pivotally connected to the main frame and projects rearwardly away from the main frame 12 such that it is inclined at an angle to the main frame and to the vertical. Each stair support assembly 30 is moveable between a stored condition (see figure 14) and a stored condition (see figures 22 and 23). Each stair support assembly 30 is configured such that, advantageously, when the main frame 12 is moved from its inoperable condition to its operable condition, the stair support assembly 30 is automatically, and gradually, moved to its operative condition. It is therefore not necessary for a user to open out the wheelchair 10 and then subsequently move the stair support assemblies 30 to their operative condition, as is required with prior art wheelchairs. One single operation of opening the wheelchair 10 renders it complete to use. An addition benefit with the stair support assembly 30 of the present invention is that it can still be moved to and from the stored condition whilst the wheelchair 10 is maintained in its operable condition.

In more detail, each stair support assembly 30 includes an endless flexible member 31 which is extends around three rotatable pulleys 36, 37 and 38.

These pulleys 36, 37 and 38 each define a point of inflexion of the endless flexible member 31, and are configured such that the length of the stair-facing portion of the endless flexible member 31 (i.e. that which extends linearly directly between the pulleys 36 and 37) is shorter than the remainder of the endless flexible member 31 (i.e. that which extends between the pulleys 36 and 37, but via the pulley 38). The lowermost pulley 38 is manufactured from a resiliently deformable material, which is beneficial because in use this area of the wheelchair 10 often engages, with significant force, an edge of the stair, which can cause damage to the pulley if it is substantially rigid / brittle, in in the

prior art wheelchairs.

The endless flexible member 31 has a castellated outer surface which is made from a resilient material, e.g. rubber. The rubber is adhered to a backing material, e.g. a woven polyamide material with minimal elongation properties.

In the present example, the endless flexible member 31 is substantially inextensible in the directions of its travel. However, it could be resiliently extensible, if desired.

The pulleys 36, 37 and 38 are supported for rotation by a support member 32 which is connected at its lower end to the axle 108 by a bracket. The support member 32, when viewed from the side, is a shallow V-shape. In other words, a lower part of the support member 32 extends substantially vertically upwardly and an upper part of the support member 32 extends diagonally upwardly away from the first part. Thus, the endless flexible member 31 defines a triangular path along which it can travel in either direction (depending on whether the wheelchair 10 is moved down or up a stair/step). As can be seen from the figures, the support member 32 affords a region 33 into which a stair-facing portion of the endless flexible member 31 is displaceable, e.g. when it is engaged with a stair or step 28. In other words, the endless flexible member 31 is able to move inwardly toward the main frame 12 when it engages a stair or step 28.

The stair support assembly 30 includes means 40 for automatically tensioning the endless flexible member 31. In this example the tensioning means is provided by a tensioning member 41 which is supported in a recess 42 in an upper part of the support member 32. in this example the tensioning member 41 includes the pulley 36, and is slidably moveable relative to the support member 32. The tensioning member 32 is biased outwardly by a resilient member 43 (e.g. a block of rubber) which is supported in the recess 42. The tensioning member 41 therefore tensions the endless flexible member 31, and maintains a desired tension in the endless flexible member 31 when it engaged with a stair or step 28.

The stair support assembly 30 also includes a frictional member 35 which is connected to a rearwardly facing surface of the support member 32 adjacent the pulley 37. The purpose of the frictional member 35 is to engage with the stair-facing portion of the endless flexible member 31 when the latter is displaced into the region 33. The frictional resistance caused by the frictional member 35 to rotation of the end'ess flexible member 31 assists a user in lowering the wheelchair 10 down a flight of stairs.

In this example an upper part of the support member 32 is connected at 55 to a link which is pivotally connected to an underside of the seat 14. The link has two parts 45, 46 which are pivotally connected to each other by a pair of brackets 56 (see figures 15, 16 and 17). The part 45 is pivotally connected to the stair support assembly 30 at 55 and the other part 46 is pivotally connected at 57 to an underside of the seat 14. The two parts 45, 46 are lockable relative to each other in a position which corresponds to the stair support assembly 30 being in its operative or rearwardly projecting condition.

Although not shown in the figures, means may be provided to hold the parts 45, 46 relative to each other in a position which corresponds to the stair support assembly 30 being in its stored condition. Such means may include a magnet for holding the parts 45, 46 relative to each other.

Figure 17 shows the working components of the device which locks the parts 45, 46 to each other. The part 45 includes a recess which slidably supports an elongate locking part 47. The locking part 47 is biased away from the part 45, toward the part 46, by a spring 52. The locking device includes a lever 48 which is pivotally supported on an axle 49 which passes through the part 45 and through an elongate aperture 59 in the locking part 47. The lever 48 includes a camming surface 54 which (as can be seen from figures 15 and 16) engages a rod 58 which passes through an aperture in the locking part 47.

Pivotal movement of the lever 48 towards the main frame 12 effects linear movement of the locking part 47 disengaging it from the recess 52 in the part 46. A spring 52 is provided for returning the lever 48 automatically to its original position.

Once the lever 48 has been moved toward the main frame 12, to unlock the parts 45, 46 from each other, the stair support assembly 30 can be pivotally moved inwardly towards the main frame 12. This functionality permits a user to store the stair support assemblies 30 if it is not required.

The configuration of the link parts 45, 46 and the locking device is also beneficial, because the parts 45, 46 are automatically locked to each other when the main frame 12 is moved to its inoperable condition. Thus, if after the stair support assemblies 30 have been moved to their stored conditions the main frame 12 of the wheelchair 10 is moved to its inoperable condition, the parts 45 and 46 are caused to move in line with each other until the locking part 47 engages the recess 53. Thus, the next time the main frame 12 is moved to its operable condition, the stair support assemblies 30 automatically moved to their operative condition, as was the case before. Therefore, the stair support assemblies 30 wifl be automatically moved to their operative conditions even if the user leaves them in their stored conditions when the user collapses the main frame 12.

As mentioned earlier, the main frame 12 includes a central link 88 which extends between the axle 108 and the underside of the seat 14. The link has two parts 89, 90 which are telescopically moveable relative to each other. The free end of the link 89 is pivotally connected to the underside of the seat 14 by an axle 82. The wheelchair beneficially includes a holding device 80 for holding the seat 14 in its operable condition. The holding device 80 includes a first part 81 which is pivotally connected at 82 to an underside of the seat 14 and a second part 86 which is connected to the link part 89. The second part 86 is a rod which extends laterally through the part 89 and has a portion which extends laterally out of each side of the part 89.

The first part 81 is U-shaped in cross-section and includes, at each side thereof, an opening 84 to receive and engage the free ends of the rod 86. In this example, the part 81 is configured so that the openings 84 automatically engage the rod 86 when the seat 14 is moved to its operable condition. This, the part 81 is configured to pivot under gravity to engage the part 86 and hold the parts 81, 86 relative to each other. A lowermost edge of each side of the part 81 includes a camming surface 83 which engages the rod 86as the seat 14 is moved to its operable condition. The camming surfaces 83 cause the part Bito pivot as it engages the part 86. When the seat nears its operable condition, the rod 86 leaves the camming surface 83 and enters the opening 83, at which point the part 81 pivots back to its original position.

The first part 81 can be pivoted out of engagement with the rod 86 manually by a user, so that the seat 14 (and the main frame 12 in this example) can be moved to its inoperable condition.

The wheelchair 10 also includes a braking device 100 for each rear wheel 20.

The components parts of the braking device 100 and their functionality are shown in detail in figures 29 through 33. In summary, the braking device 100 has a first part 102 which is held rotationally fast relative to the wheel 20, and a second part 110 which is slidably connected to the frame part 26. The second part 110 includes a projecting formation or pin 102 (having a tapered point at its free end) which is moveable to pierce a surface of the first part 102, thus braking or at least inhibiting rotation of the wheel 20.

In more detail, the rear wheel 20 is supported on a hub 120 which is itself rotatably supported on the axle 108. The axle 108 extends across the wheelchair 10 between the rear wheels 20, where it passes, at each side, through the hub 120. Each end of the axle 108 is held in position by a connection part 106 which extends through an aperture 113 in a rear end of the frame part 26. An outermost side of the hub 120 includes a flange 102 which rotates with the wheel 20. The second part 110 in this example is an annular part which is slidably supported on the exterior of the frame part 26.

The annular part 110 is slidable relative to the frame part 26 but its movement is limited by a pin 112 which passes through the part 110 and through aligned slots in the upper and lower walls of the frame part 26.

An inner and rearwardly facing side of the annular part 110 supports the pin 104. Inside the frame part 26 is provided a U-shaped part 116 which is aligned vertically with the open end thereof facing towards a front of the wheelchair 10. The U-shaped part 116 is connected to the pin 112, and thus moves the pin 112 and annular part 100 when it is moved. An end part of the U-shaped part 116 is inclined at an angle to the vertical. Essentially, the U-shaped part 116 forms three sides of a parallelogram. The pin 112, and thus the annular part 110 are biased away from the flange 102 by a spring 114 which is connected to the part 106.

The braking device 100 includes a lever 118 which is pivotally connected to the frame part 26 by an axle 115 and extends rearwardly away from the frame part 26 The lever 118 supports a further axle 119 which itself supports a bushing 117. The axle 119 is spaced from the axle 115 and between them they sandwich the end part of the U-shaped part 116.

As shown in figure 31, when the lever 118 is in its unbraked position (i.e. with a free end thereof pointing upwardly) the pin 104 is spaced from the flange 102. When the lever is moved downwardly, e.g. by a user's foot, the bushing 117 slides down the inclined end of the U-shaped part 116. Because the lever is fixed pivotally relative to the frame part 26, pivotal movement of the lever 118 downwardly effects linear movement of the annular part 110 until the pin 104 supported therein pierces a circumferential surface of the flange 102.

Thus, the wheel 20 is braked or at least inhibited from rotating whilst the lever 118 and pin 104 are in this position. To unbrake the wheel 20, the user needs to apply a force to move the lever 118 upwardly, where it will then be returned to its original position by the spring 114.

The braking device 100 in accordance with the present invention is beneficial over the prior art, because it is not necessary to provide relatively large surfaces which frictionally engage with each other to give the required braking force. The braking device 100 is therefore more compact and does not suffer from reduced braking when subjected to wet or damp conditions. The material selected for the flange 102 in this example is a polyamide, e.g. Nylon®, which permits the pin 104 (metal in this example) to penetrate its surface, but does not degrade over extended applications of braking. After many applications of the brake, the circumferential surface of the flange 102 will contain a plurality of holes caused by the pin 104 piercing the surface thereof. As a result, when the brake is used, the pin 104 may not need to pierce a fresh hole in the surface of the flange 102, but could, instead engage in a hole that was made during a previous application of the brake. The pin 104 need not pierce deeply into the flange 102. This is because the shearing forces experienced by the pin 104 in use will not be particularly high. Indeed, the inclines on which the wheelchair 10 will be brake will not be at all steep, and thus the depth of penetration show in the figures is adequate to prevent the rear wheels 20 from rotating and thus prevent the wheelchair 10 from moving.

When used in this specification and claims, the terms "comprises" and "comprising" and variations thereof mean that the specified features, steps or integers are included. The terms are not to be interpreted to exclude the presence of other features, steps or components.

The features disclosed in the foregoing description, or the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS1. A wheelchair having a main frame which is moveable between an operable and an inoperable condition, and vice versa, the wheelchair including at least one stair support assembly connected to a rear of the main frame, the stair support assembly being moveable between a stored and a operative condition, wherein, when the main frame is moved from its inoperable condition to its operable condition, the stair support assembly is automatically moved to its operative condition.
2. A wheelchair according to claim 1 wherein the stair support assembly, when in its operative condition, projects rearwardly away from the main frame.
3. A wheelchair according to claim 1 or claim 2 wherein the stair support assembly, when in its operative condition, is inclined at an angle relative to the main frame.
4. A wheelchair according to any preceding claim wherein during the course of movement of the main frame from its inoperable and its operable condition, the stair support assembly moves gradually to its operative condition.
5. A wheelchair according to any preceding claim wherein the stair support assembly is moveable from its operative condition to its stored condition, and vice versa, whilst the main frame is maintained in its operable condition.
6. A wheelchair according to any preceding claim wherein the wheelchair includes means for holding the stair support assembly in its stored condition
7. A wheelchair according to any preceding claim wherein the stair support assembly is pivotally connected to the main frame and is pivotally moveable between its stored and operative conditions.
8. A wheelchair according to any preceding claim wherein the stair support assembly is connected to a seat of the wheelchair.
9. A wheelchair according to claim 8 wherein the stair support assembly is pivotally connected to the seat.
10. A wheelchair according to any preceding claim wherein the seat is pivotally connected to the main frame.
11. A wheelchair according to claim 8, claim 9 or claim 10 wherein the stair support assembly is connected to the seat by a link.
12. A wheelchair according to claim 11 wherein the link includes at least two parts which are pivotally connected to each other, one part being connected to the stair support assembly and the other part being connected to the seat, and wherein the at least two parts are lockable relative to each other in a position which corresponds to the stair support assembly being in its operative condition.
13. A wheelchair according to claim 12 wherein means is provided for holding the links relative to each other in a position which corresponds to the stair support assembly being in its stored condition.
14. A wheelchair according to any preceding claim as appendant on claim 5 wherein if the stair support assembly has been moved to its stored condition and the main frame is then subsequently moved to its inoperable condition, the stair support assembly is configured such that it will automatically move to its operative condition the next time the main frame is moved to its operable condition.
15. A wheelchair according to any preceding claim wherein the wheelchair includes a holding device for holding the main frame in its operable condition.
16. A wheelchair according to any preceding claim wherein the stair support assembly includes an endless flexible member which is supported by and extends around at least two rotatable members.
17. A wheelchair according to any preceding claim wherein the wheelchair includes two stair support assemblies, one provided at each side of the main frame.
18. A wheelchair having at least one stair support assembly connected to a rear of a main frame of the wheelchair, the stair support assembly having an endless flexible member which is supported for rotation by a support member which provides at least two points of inflexion of the endless flexible member, wherein the support member affords a region into which the endless flexible member is displaceable.
19. A wheelchair according to claim 18 wherein the support member affords a region into which a stair-facing portion of the endless flexible member is displaceable.
20. A wheelchair according to claim 18 or claim 19 wherein the stair support assembly includes a frictional member which is connected to the support member and is engageable with the stair-facing portion of the endless flexible member when the latter is displaced into said region.
21. A wheelchair according to any one of claims 18 to 20 wherein the stair-facing portion of the endless flexible member extends between two points of inflexion, and wherein the length of the stair-facing portion of the endless flexible member is shorter than the remainder of the endless flexible member.
22. A wheelchair according to any one of claims 18 to 21 wherein the stair-facing portion of the endless flexible member extends linearly between the two points of inflexion, and wherein the support member provides a further point of inflexion of the remainder of the endless flexible member.
23. A wheelchair according to any one of claims 18 to 22 wherein the support member provides three points of inflexion, said inflexion points being provided by rotatable elements.
24. A wheelchair according to claim 23 wherein a lowermost rotatable element is resiliently deformable.
25. A wheelchair according to any one of claims 18 to 24 wherein the support member includes means for automatically tensioning the endless flexible member.
26. A wheelchair having at least one stair support assembly connected to a rear of a main frame of the wheelchair, the stair support assembly having an endless flexible member which is supported for rotation by a support member which provides at least two points of inflexion of the endless flexible member, wherein the stair support assembly includes means for automatically tensioning the endless flexible member
27. A wheelchair according to claim 26 wherein the means for automatically tensioning the endless flexible member includes a tensioning member which is supported by the support member, the tensioning member being biased into engagement with a portion of the endless flexible member.
28. A wheelchair according to claim 27 wherein the tensioning member biases one of the at least two points of inflexion away from the other point(s) of inflexion.
29. A wheelchair according to claim 27 or claim 28 wherein the tensioning member is slidably supported by the support member.
30. A wheelchair according to any one of claims 26 to 29 wherein the tensioning member is supported in a recess in the support member.
31. A wheelchair according to any one of claims 27 to 30 wherein the tensioning member includes a rotatable element which engages the endless flexible member.
32. A wheelchair according to claim 31 wherein the rotatable element is biased away from the support member and into engagement with an underside of the endless flexible member.
33. A wheelchair according to any one of claims 27 to 32 wherein the tensioning member is biased into engagement with a portion of the endless flexible member by a resiliently deformable member which is support by the support member.
34. A wheelchair according to claim 33 wherein the tensioning member is biased into engagement with a portion of the endless flexible member by a spring which is support by the support member.
35. A wheelchair having at least one lifting device for assisting in lifting the wheelchair, the lifting device including a handle which is connected to an elongate member, the elongate member being slidably moveable relative to the main frame between a stored condition and a fully deployed condition, wherein the lifting device includes means for holding the elongate member at any position between the stored and fully deployed conditions.
36. A wheelchair according to claim 35 wherein the elongate member is slidably supported by a frame member and wherein the holding means includes at least one engaging member which engages a part or surface of the frame member.
37. A wheelchair according to claim 36 wherein the engaging member frictionally engages a part or surface of the frame member.
38. A wheelchair according to claim 36 or claim 37 wherein the engaging member is urged into engagement with a part or surface of the frame member.
39. A wheelchair according to claim 38 wherein including a part which urges the engaging member into engagement with a part or surface of the frame member.
40. A wheelchair according to claim 39 wherein the urging part is biased towards the engaging member.
41. A wheelchair according to claim 39 or claim 40 wherein movement of the urging part in a first direction urges the engaging member away therefrom in a direction substantially perpendicularly thereto.
42. A wheelchair according to claim 39, claim 40 or claim 41 wherein the urging part is tapered.
43. A wheelchair according to any one of claims 39 to 42 wherein a surface of the engaging member, which surface abuts the urging part, is inclined at an angle relative to its direction of movement.
44. A wheelchair according to claim 43 wherein the surface is sloped, conical or tapered.
45. A wheelchair according to any one of claims 35 to 44 wherein the lifting device is provided with an actuator member, positioned adjacent the handle, the actuator controlling operation of the holding means.
46. A wheelchair according to claim 45 wherein the actuator member is positioned such that it can be operated by a digit of a user's hand when said hand is grasping the handle.
47. A wheelchair according to claim 45 or 46 when appendant to any one of claims 39 to 44 wherein the actuator member is connected to the urging part by a link, and actuation of the actuator member moves the urging part away from the engaging member.
48. A wheelchair according to any one of claims 35 to 47 wherein the holding means includes a pair of engaging members positioned opposite each other, each engaging member engaging a respective part or surface of the frame member.
49. A wheelchair according to claim 48 wherein the engaging members are positioned opposite each other and engage opposing part or surfaces of the frame member.
50. A wheelchair according to any one of claims 35 to 49 including a pair of lifting devices, one positioned at each side of the wheelchair.
51. A device for holding a first part of an apparatus relative to a second part of an apparatus, the first part having a holding formation and the second part having a receiving formation, wherein the holding formation is receivable in the receiving formation when the former is oriented in a first orientation relative to the receiving formation, and wherein, when the holding formation is subsequently moved to a second orientation relative to the receiving formation, the receiving formation prevents the holding formation from being withdrawn therefrom.
52. A device according to claim 51 wherein the holding formation is rotatably moveable about an axis between its first and second orientations.
53. A device according to claim 52 wherein the first and second orientations of the holding formation are spaced substantially 90° from each other about the axis of rotation of the holding formation.
54. A device according to any one of claims 51 to 53 wherein a width dimension of the holding formation, when in its first orientation, is smaller than a width dimension of the receiving formation.
55. A device according to any one of claims 51 to 54 wherein a width dimension of the holding formation, when in its second orientation, is larger than a width dimension of the receiving formation.
56. A device according to any one of claims 51 to 55 wherein the receiving formation is an aperture in the first part.
57. A device according to claim 56 wherein the aperture is elongate.
58. A device according to any one of claims 51 to 57 wherein the holding formation is substantially d iscshaped.
59. A device according to any one of claims 51 to 58 wherein the device includes a pair of holding formations and a pair of receiving formations, one pair being provided at one side of the apparatus and the other pair being provided at an opposite side of the apparatus.
60. A device according to claim 59 wherein the holding formations are connected to each other by an axle.
61. A device according to claim 59 or claim 60 wherein the holding formations are synchronously moveable between their respective first and second orientations.
62. A device according to any one of claims 51 to 61 wherein the device includes a graspable handle for moving the holding formation(s) between its first and second orientations.
63. A device according to claim 62 wherein the graspable handle includes a formation for holding the handle in a position which corresponds to the holding formation being in its first orientation.
64. A device according to claim 62 or claim 63 wherein the graspable handle includes a formation for holding the handle in a position which corresponds to the holding formation being in its second orientation.64. A device according to any one of claims 51 to 64 wherein the first and second parts are frame parts of a wheelchair.66. A device according to claim 65 wherein one of the first or second parts is pivotally moveable relative to the other of the first or second parts.67. A device according to claim 66 wherein one of the first or second parts is a pivotally moveable footrest.68. A device according to any one of claims 65 to 67 as appendant to claim 62, claim 63 or claim 64 wherein the graspable handle is provided at one side of the wheelchair.69. A device according to claim 68 wherein a pair of graspable handles are provided, one position at each side of the wheelchair, wherein movement of either of the graspable handles effects movement of the holding formation(s).70. A wheelchair having a first side frame part and a second side frame part, wherein the first and second side frame parts are connected to each other by a flexible element which permits the first and second side frame parts to move relative to each other.71. A wheelchair according to claim 70 wherein the flexible element is provided as a portion of a part which connects the first and second side frame parts.72. A wheelchair according to claim 71 wherein the flexible element is provided as a portion of a part of a footrest of the wheelchair.73. A wheelchair according to claim 72 wherein the flexible element is provided as part of a device for holding the footrest in an operable condition.74. A wheelchair according to claim 73 wherein the flexible element is provided as part of an axle of said device, the axle having provided at each end thereof a holding formation, each of which is engageable with a respective receiving formation on the wheelchair.75. A wheelchair according to any one of claims 70 to 74 wherein the flexible element is made from a polyamide.76. A wheelchair according to any one of claims 70 to 74 wherein the flexible element is part of a device according to any one of claims 51 to 6769 77. A wheelchair having a main frame and a seat, the seat being pivotally connected to the main frame and being pivotally moveable between an operable and an inoperable condition, the wheelchair including a holding device for holding the seat in its operable condition, wherein the holding device includes a first part which is connected to the seat an a second part provided on, connected to or supported by the main frame, wherein when the seat is moved to its operable condition the first part moves under gravity to engage the second part.78. A wheelchair according to claim 77 wherein the first part of the holding device includes a camming surface which engages the second part of the holding device as the seat is moved to its operable condition.79. A wheelchair according to claim 78 wherein as the seat is moved to its operable condition the camming surface causes the first part to move away from the second part.80. A wheelchair according to claim 78 or claim 79 wherein as the seat nears its operable condition, the second part no longer engages the camming surface, and the first part moves under gravity to engage the second part.81. A wheelchair according to any one of claims 77 to 80 wherein the holding device is provided beneath the seat.82. A wheelchair according to any one of claims 77 to 81 wherein the first part of the holding device is connected to an underside of the seat.83. A wheelchair according to any one of claims 77 to 82 wherein the first part of the holding device is pivotally connected to the seat and pivots under gravity to engage the second part when the seat is moved to its operable condition.4. A wheelchair according to any one of claims 77 to 83 wherein the second part includes a projection and the first part includes an opening to receive the projection.85. A wheelchair according to claim 84 wherein the projection extends in a direction substantially parallel with the pivoting axis of the first part.86. A wheelchair according to any one of claims 77 to 85 wherein the seat is connected to the main frame by a link, a first part of the link being connected to the seat and a second part of the link being connected to the main frame, the first and second parts of the link being slidably moveable relative to each other, and wherein the second part of the holding device is connected to the second part of the link.87. A wheelchair according to claim 86 wherein the first and second parts of the link are telescopically moveable relative to each other.88. A wheelchair according to claim 86 or claim 87 wherein the first part of the link is pivotally connected to the frame.89. A wheelchair according to claim 86, claim 87 pr claim 88 wherein the second part of the link is pivotally connected to the main frame.90. A wheelchair according to any one of claims 77 to 89 wherein the first part can be moved out of engagement with the second part manually by a user, so that the seat can be moved to its inoperable condition.91. A braking device for a wheel which is supported for rotation by a wheel axle connected to a body, the braking device including a first part which is rotationally fast relative to the wheel, and a second part connected to the body, the second part including a projecting formation which is moveable to pierce a surface of the first part.92. A braking device according to claim 91 wherein the second part is biased to a position in which the projecting formation does not pierce a surface of the first part.93. A braking device according to claim 91 or claim 92 wherein the projecting formation is moveable to the position in which it pierces the surface of the first part by a user-operable actuator member.94. A braking device according to anyone of claims 91 to 93 wherein the user-operable actuator member is a lever.95. A braking device according to anyone of claims 91 to 94 wherein the user-operable actuator member is a foot -operable lever.96. A braking device according to anyone of claims 91 to 95 wherein the projecting formation tapers to a point at an end which pierces the first part.97. A braking device according to anyone of claims 91 to 96 wherein the first part is rotatably supported on the wheel axle.98. A braking device according to anyone of claims 91 to 97 wherein the projecting formation pierces a circumferential surface of the first part.99. A braking device according to anyone of claims 91 to 98 wherein the projecting formation pierces a radially outwardly facing circumferential surface of the first part.100. A braking device according to anyone of claims 91 to 99 wherein the second part is slidable relative to the body.101. A braking device according to anyone of claims 91 to 100 wherein the second part is substantially annular and includes an aperture to receive a part of the body, the second part being slidable along that part of the body.102. A braking device according to anyone of claims 91 to 101 wherein the braking device includes a third part to limit movement of the second part relative to the body.103. A braking device according to claim 102 wherein the third part limits movement of the second part away from the first part.104. A wheelchair substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.105. A braking device substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.106. A device for holding a first part of a wheelchair relative to a second part of a wheelchair substantially as hereinbefore described with reference to and/or as shown in the accompanying drawings.107. Any novel feature or novel combination of features described herein and/or in the accompanying drawings.