TECHNICAL FIELD
[0001] The present invention generally relates to a wheelchair, in particular a manual wheelchair
intended for bariatric or heavy-duty use, also referred to as bariatric wheelchair
or heavy-duty wheelchair.
BACKGROUND OF THE INVENTION
[0002] Bariatric wheelchairs are known as such in the art and are typically based on enlarged,
more robust iterations of conventional wheelchairs. Typical bariatric wheelchairs
are in essence widened versions of conventional wheelchairs with larger seating areas
and reinforced chassis structure designed to cope with the inherent requirements that
come with increased load.
[0003] As a matter of fact, when it comes to the design of bariatric wheelchairs, little
consideration has been given (so far at least) to comfort for the patient, wheelchair
use and handling, as well as aesthetics. As a matter of fact, known bariatric wheelchairs
provide limited comfort for the patient, are more difficult to use and handle than
conventional wheelchairs, are visually bulky and have too much of a "medical" look,
and the aesthetics thereof could accordingly be greatly improved.
[0004] Figure 11 is a greyscale photographic illustration of a conventional bariatric wheelchair
as sold for instance by Invacare® Corporation under the product designation Invacare
9000 Topaz™, which bariatric wheelchair is typically available with a seating width
ranging from 20 to 30 inches (i.e. approx. 500 millimeters to 760 millimeters) and
has a weight capacity exceeding 250 kg.
[0005] US Patent Publication No.
US 2014/0252747 A1 discloses wheelchair designs and enhancements for use with conventional wheelchair
designs, including bariatric extension panels allowing extension and widening of the
seating area if need be. The proposed wheelchair designs are especially intended to
be used in high security areas (such as prisons and psychiatric wards) and are therefore
ill-suited for more conventional, day-to-day uses.
[0006] There is therefore a need for an improved wheelchair design that is more suited for
bariatric patients.
SUMMARY OF THE INVENTION
[0007] A general aim of the invention is to provide a wheelchair, which improves comfort
for bariatric patients as well as handling of the wheelchair by such population of
wheelchair users.
[0008] A further aim of the invention is to provide such a wheelchair that exhibits a more
aesthetically pleasing appearance.
[0009] Yet another aim of the invention is to provide such a wheelchair that is both lighter
and easier to handle, but which does not compromise robustness.
[0010] Still another aim of the invention is to provide such a wheelchair that can be more
easily handled and transported by bariatric patients, in particular through narrow
passages like doorways or elevators.
[0011] These aims are achieved thanks to the solutions defined in the claims.
[0012] In accordance with the invention, there is provided a wheelchair as defined in claim
1, in particular a manual wheelchair for bariatric or heavy-duty use, comprising a
wheelchair chassis, a seating area provided on the wheelchair chassis, a backrest
supported onto the wheelchair chassis, as well as front wheels and rear wheels provided
on the wheelchair chassis to allow wheeling of the wheelchair. According to the invention,
the wheelchair further comprises a rolling support structure provided at a rear portion
of the wheelchair to support the wheelchair in an upright position in which the wheelchair
is tilted back and is supported by the rolling support structure to allow displacement
of the wheelchair in the upright position, which rolling support structure includes
at least three, in particular four, rolling elements providing rolling support for
the wheelchair in the upright position.
[0013] The rolling elements preferably provide omnidirectional rolling support for the wheelchair
in the upright position and may in particular advantageously be ball casters.
[0014] In accordance with a preferred embodiment of the invention, at least part, especially
all, of the rolling elements are supported onto the wheelchair chassis.
[0015] According to a particularly advantageous embodiment of the invention, in the upright
position of the wheelchair, the rear wheels do not rest on the ground, each rear wheel
being preferably mounted on the wheelchair chassis by means of a quick-release mechanism.
[0016] By way of preference, the rolling support structure is at least partly deployable
between a storage position at a rear portion of the wheelchair chassis and a working
position where the rolling elements are fully deployed to provide rolling support
for the wheelchair in the upright position.
[0017] The rolling elements may furthermore include at least a pair of lower rolling elements
that also act as anti-tip devices.
[0018] In accordance with a particularly preferred embodiment of the invention, a front-to-rear
position of a rear-wheel axis of the rear wheels along the wheelchair chassis is adjustable
and the rolling support structure is supported in such a way that any adjustment of
the front-to-rear position of the rear-wheel axis of the rear wheels leads to a corresponding
adjustment of a front-to-rear position of the rolling support structure. In this context,
the rolling support structure may in particular be supported in a fixed relationship
with respect to the front-to-rear position of the rear wheel axis.
[0019] In accordance with yet another preferred embodiment of the aforementioned wheelchairs,
the wheelchair chassis is designed as a rigid, non-foldable chassis and is made of
lightweight materials, in particular aluminum. In this context, the backrest may advantageously
be foldable frontward onto the seating area.
[0020] More particularly, the wheelchair chassis may be designed as a rigid, non-foldable
chassis comprising side frames provided on left and right sides of the wheelchair
chassis, each comprising a rear wheel support to support a corresponding one of the
rear wheels at a position defining the rear-wheel axis, a front-to-rear position of
the rear wheel support along each side frame, and therefore the front-to-rear position
of the rear-wheel axis, being adjustable. In this particular context, the rolling
support structure can be supported in a fixed relationship with respect to the front-to-rear
position the rear-wheel axis.
[0021] In the context of this aforementioned embodiment, the rolling support structure may
be supported directly onto the rear wheel supports or onto a rear cross member of
the wheelchair chassis, which rear cross member is interposed between the rear wheel
supports.
[0022] In accordance with another aspect of the invention, the backrest may advantageously
exhibit a lower backrest portion supported onto the wheelchair chassis, next to the
seating area, the seating area and lower backrest portion having a first width that
is selected to accommodate a wheelchair user's hips. In accordance with this other
aspect of the invention, the backrest further exhibits an upper backrest portion,
in the vicinity of the wheelchair user's shoulders, having a second width that is
smaller than the first width, which second width is selected to liberate space for
movement of the wheelchair user's arms and shoulders.
[0023] By way of preference, the first width is selected to accommodate a wheelchair user's
nominal hip width ranging between 500 millimeters and 800 millimeters and the second
width is selected so as not to exceed a wheelchair user's nominal shoulder articulation
width ranging between 400 millimeters and 600 millimeters.
[0024] The backrest may advantageously comprise a backrest frame acting as structural element
of the backrest, which backrest frame is shaped to exhibit lower and upper frame portions
supporting respectively the lower and upper backrest portions. In this context, the
backrest frame preferably includes a pair of back canes having lower ends supported
onto the wheelchair chassis and being separated by the first width, which back canes
are curved inwardly so that upper ends thereof, in the vicinity of the wheelchair
user's shoulders, are separated by the second width.
[0025] According to another aspect of the present invention, the wheelchair may further
comprises a pair of removable front canes supported into corresponding sockets provided
on the wheelchair chassis next to a front part of the seating area, which pair of
removable front canes can take at least a first position in which the removable front
canes act as transfer aid devices to assist the wheelchair user in raising up from
or, conversely, sitting onto the seating area of the wheelchair, each removable front
cane exhibiting a handle portion that is oriented frontward, in the first position.
By way of preference, the removable front canes are reversible and can take at least
a second position, opposite to the first position, with the handle portion being oriented
rearward, to act as forearm supports for the wheelchair user.
[0026] Further advantageous embodiments of the invention are discussed below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0027] Other features and advantages of the present invention will appear more clearly from
reading the following detailed description of embodiments of the invention which are
presented solely by way of non-restrictive examples and illustrated by the attached
drawings in which:
Figures 1A and 1B are greyscale perspective views, respectively from the front and
the rear, of a wheelchair in accordance with a first embodiment of the invention ;
Figures 2A and 2B are black-and-white perspective views corresponding respectively
to Figures 1A and 1B ;
Figure 2C is a perspective frontal view of the wheelchair of Figures 2A-2B ;
Figure 2D is a perspective view of the wheelchair of Figures 2A-2B as seen from the
right-hand side ;
Figure 2E is a perspective view of a cross-section of the wheelchair of Figures 2A-2B
as seen from the same perspective as Figure 2D, which cross-section is taken along
a median plane A-A as depicted in Figure 2C ;
Figure 3A is a perspective view of the wheelchair of Figures 2A-2B as seen from the
same perspective as Figure 2A, where the seat upholstery, backrest trim and wheelchair
cushions have been omitted ;
Figure 3B is a perspective view of the wheelchair of Figure 3A as seen from the right-hand
side, like Figure 2D ;
Figure 3C is a perspective view of a cross-section of the wheelchair of Figure 3A
as seen from the same perspective as Figure 3B, which cross-section is taken along
the same median plane A-A as depicted in Figure 2C ;
Figure 3D is a partial perspective view of the cross-section of Figure 3C taken from
a different perspective and focusing on a rear wheel support region of the wheelchair;
Figure 4 is a perspective view of the wheelchair chassis and backrest frame of the
wheelchair of Figures 2A-2E ;
Figure 5A is a side view of the wheelchair chassis of Figure 4 taken from the left-hand
side;
Figures 5B and 5C are enlarged partial side views of a rear portion of the wheelchair
chassis shown in Figure 5A highlighting operation of a deployable rolling support
structure provided at the rear-end of the wheelchair chassis ;
Figure 5D is a view of the wheelchair of Figures 2A-2E, with folded backrest, sitting
in an upright position in which the wheelchair is tilted back and is supported by
the deployed rolling support structure ;
Figures 6A and 6B are respectively a perspective view and a front view of a backrest
frame forming part of the backrest of the wheelchair of Figures 2A-2E ;
Figure 6C is a side view of the backrest frame of Figures 6A-6B taken from the right-hand
side ;
Figures 7A and 7B are schematic perspective views illustrating a backrest design in
accordance with a preferred aspect of the invention and highlighting the resultingly
improved hand rim accessibility of the wheelchair;
Figure 7C is a schematic anatomic view of an overweight person and highlighting relevant
morphologic characteristics that are preferably taken into consideration for the design
of the backrest of the wheelchair;
Figures 8A and 8B are schematic side views of the wheelchair seating area highlighting
a preferred backrest profile accommodating distinct wheelchair user morphologies ;
Figures 9A to 9C are schematic side views of the wheelchair of Figures 2A-2E highlighting
a pair of reversible front canes provided at the front of the wheelchair chassis and
used, in a first position thereof shown in Figures 9A and 9B, as devices to assist
the wheelchair user in raising up from or, conversely, sitting onto the seating area
of the wheelchair and, in second position shown in Figure 9C, as forearm supports
;
Figures 10A to 10C are respectively a perspective view and two cross-sectional views
of a wheelchair in accordance with another embodiment of the invention ; and
Figure 11 is a greyscale photographic illustration of a conventional bariatric wheelchair
as sold for instance by Invacare® Corporation under the product designation Invacare
9000 Topaz™.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0028] The present invention will be described in relation to various illustrative embodiments.
It shall be understood that the scope of the invention encompasses all combinations
and sub-combinations of the features of the wheelchair disclosed herein.
[0029] As described herein, when two or more parts or components of the wheelchair are described
as being connected, secured or coupled to one another, they can be so connected, secured
or coupled directly to each other or through one or more intermediary parts.
[0030] The expression "manual wheelchair" as used herein is intended to refer to a wheelchair
that can be wheeled manually by the user. This expression also encompasses power-assisted
manual wheelchairs that are additionally provided with means to assist propulsion.
[0031] Referring to Figures 1A and 1B, there is shown a bariatric (or heavy-duty) wheelchair
designated generally by reference numeral 1 in accordance with a first embodiment
of the invention. Figures 1A and 1B are greyscale perspective views, respectively
from the front and from the rear, of the wheelchair 1. Figures 2A and 2B are black-and-white
perspective views of the wheelchair 1 (without shadings) corresponding respectively
to Figures 1A and 1B. Figures 2C and 2D are respectively a perspective frontal view
of the wheelchair 1 and a perspective view of the wheelchair 1 as seen from the right-hand
side. Figure 2E, on the other hand, is a perspective view of a cross-section of the
wheelchair 1 as seen from the same perspective as Figure 2D, which cross-section is
taken along a median plane A-A as depicted in Figure 2C.
[0032] The wheelchair 1 comprises a wheelchair chassis 30, a seating area 10 provided on
the wheelchair chassis 30, a backrest 20 supported onto the wheelchair chassis 30,
as well as front wheels 45 and rear wheels 40 provided on the wheelchair chassis 30
to allow wheeling of the wheelchair 1, as is typical in the art. The wheelchair 1
may optionally, but preferably, be equipped with a pair of footrests 50, known as
such in the art, that are mounted on a front end of the wheelchair chassis 30.
[0033] Further elements (not shown in the illustrations) could be provided, including armrests
and/or elbow supports to provide support for the wheelchair user's arms or elbows,
as well as clothing guards or like protective panels interposed between the rear wheels
40 and the seating area 10 to prevent clothing from getting stuck or caught in the
rear wheels 40. This being said, armrests or armpads as found typically on conventional
wheelchairs (see e.g. Figure 11) could in effect be detrimental in that they potentially
interfere with a proper handling and driving of the wheelchair by the wheelchair users.
In that respect, it may be preferable not to equip the wheelchair of the invention
with any armrest or armpad at all.
[0034] The rear wheels 40 are each typically equipped with a hand rim 41 allowing the wheelchair
user to wheel the wheelchair 1 in any desired direction as is known in the art (see
also Figure 7A which illustrates handling and wheeling of a wheelchair 1' in accordance
with a particularly preferred embodiment of the present invention). The front wheels
45, on the other hand, are mounted on the wheelchair chassis 30 so as to pivot about
a vertical axis, here by means of a pair of front wheel supports (or forks) 46.
[0035] In the illustrated example, the wheelchair chassis 30 is designed as a rigid, non-foldable
chassis and is preferably made of lightweight materials, in particular aluminum. While
a foldable chassis could in theory be contemplated within the context of the present
invention (see e.g. International Publication No.
WO 2014/020377 A1, the disclosure of which is incorporated herein by reference), the necessary structural
elements to allow the chassis to be foldable would inherently increase weight, which
is counterproductive for application as a bariatric wheelchair.
[0036] By way of preference, the wheelchair chassis 30 therefore exhibits a rigid construction
(as depicted e.g. in Figure 4) with a pair of side frames (partly visible in Figures
1A-1B and 2A-2E and designated in the following by reference numeral 310), on the
left and right sides of the wheelchair chassis 30, each supporting a rear wheel 40
and front wheel 45, which side frames 310 are connected together by means of a plurality
of cross members (also partly visible in Figures 1A-1B and 2A-2E and designated in
the following by reference numerals 301, 302 and 303).
[0037] In the illustrated example, cross member 301 is provided at a location of the wheelchair
chassis 30 corresponding basically to a front part of the seating area 10, while cross
member 302 is provided in a middle portion of the wheelchair chassis 30, under the
seating area 10, and cross member 303 is provided at a rear portion of the wheelchair
chassis 30. A particularly preferred configuration of the wheelchair chassis 30 will
be detailed further below with reference to Figures 3A-3D, 4 and 5A-5D.
[0038] Turning to the seating area 10, a self-supporting seat upholstery 15 is provided
on the wheelchair chassis 30, which seat upholstery 15 consists of a sheet of resistant
material adapted to suitably support a wheelchair user, such as vinyl or nylon material.
In the present instance, the seat upholstery 15 is supported onto the upper portion
of the wheelchair chassis 30, namely between a pair of upper frame members 310A (see
e.g. Figures 3D, 4 and 5A) each forming a part of the side frames 310. Any other suitable
seating area configuration could be contemplated within the scope of the present invention,
and the particular seating area configuration illustrated in Figures 1A-1B and 2A-2E
is only illustrative of a possible, non-limiting configuration.
[0039] The backrest 20 preferably comprises a backrest frame 21 acting as structural element
of the backrest 20, which backrest frame 21 is supported onto the wheelchair chassis
30 by means of a pair of backrest frame supports 320 that are partly visible in Figure
2D (see also Figures 3A-3D, 4 and 5A-5D). Such backrest frame supports 320 are especially
designed, in the illustrated embodiments, so as to allow the backrest 20 to be folded
(or collapsible) frontward onto the seating area 10, as depicted for instance in Figure
5D. The backrest frame supports 320 can in particular be designed in accordance with
International Publication No.
WO 2014/020378 A1, the disclosure of which is incorporated herein by reference. The relevant mounting
location at which the backrest 20 is supported onto the wheelchair chassis 30 is designated
in Figures 2D, 2E, 3B, 3C and 5A by reference P. In the illustrated embodiments, mounting
location P in effect corresponds to a pivotal axis of the backrest with respect to
the wheelchair chassis.
[0040] Only part of the backrest frame 21 is visible in Figures 1A-1B and 2A-2E, the visible
part being a push handle 215 that forms an integral part of the backrest frame 21
in this embodiment. As the wheelchair chassis 30 is rigid and not foldable in the
present instance, the push handle 215 can be designed as a single transverse bar connecting
both sides of the backrest frame 21. The backrest frame 21 further comprises a pair
of back canes (not visible in Figures 1A-1B and 2A-2D but designated in the following
by reference numeral 210 - see e.g. Figures 3A-3C and 4 that will be discussed more
extensively in the following). These back canes 210 are each supported at a lower
end onto the wheelchair chassis 30, namely via the aforementioned backrest frame supports
320.
[0041] In accordance with a preferred embodiment of the invention, as highlighted in particular
by the illustration of Figure 2C, the backrest 20 exhibits a lower backrest portion
supported onto the wheelchair chassis 30, next to the seating area 10. The seating
area 10 and lower backrest portion of the backrest 20 have a first width W1 that is
selected to accommodate a wheelchair user's hips. The backrest 20 further exhibits
an upper backrest portion, in the vicinity of the wheelchair user's shoulders, having
a second width W2 that is smaller that the aforementioned first width W1, which second
width W2 is selected to liberate space for movement of the wheelchair user's arms
and shoulders (see also Figures 7A and 7B).
[0042] By way of preference, the first width W1 is selected to accommodate a wheelchair
user's nominal hip width WH (see Figure 7C) ranging between 500 millimeters and 800
millimeters, while the second width W2 is selected not to exceed a wheelchair user's
nominal shoulder articulation width WS (see again Figure 7C) ranging between 400 millimeters
and 600 millimeters.
[0043] Thanks to these dimensional considerations regarding the design of the backrest,
the wheelchair user has far better mobility in the arms and shoulders, leading to
better ergonomics and a greater amplitude of arm movement. Indeed, on all existing
bariatric wheelchairs (as for instance depicted in Figure 11), the backrest typically
includes two vertical back canes, separated by a distance corresponding to the aforementioned
wheelchair user's nominal hip width WH (as schematically illustrated by the two vertical
dashed lines in Figure 7C), which vertical back canes in effect restrain arm movement
as they end up directly behind the upper portion of the wheelchair user's arms. In
contrast, thanks to this preferred embodiment of the invention, space for movement
of the arms and shoulders is liberated.
[0044] Tests carried out by the Applicant have demonstrated that the wheelchair user can
gain approximately 20% in amplitude of movement compared to typical bariatric wheelchairs
having conventional backrests. This amplitude of movement is further improved by adjusting
the position of the rear wheel axis to be more frontward (compared to conventional
wheelchairs), which is possible without compromising wheelchair stability as a center
of gravity of overweight persons inherently shifts forward. In that respect, it is
particularly advantageous to design the wheelchair in such a way that a front-to-rear
position of the rear wheel axis O along the wheelchair chassis is adjustable between
a plurality of selected positions so as to change a horizontal distance separating
the rear wheel axis O and the mounting location P of the backrest - which horizontal
distance is referred to as distance D2 in Figures 2D, 3B, 3C and 5A. By way of illustration,
the selected positions could be such that distance D2 can be changed between the following
values: 50, 75, 100 and 125 millimeters, which value are given for the purpose of
illustration only. This adaptability is especially useful in order to possibly adjust
the wheelchair configuration to different user weights and to the resulting shift
in the user's center of gravity. The relevant wheelchair configuration for a given
user can especially be selected with consideration of e.g. the normative definition
of the position of the user's center of gravity pursuant to ISO norm 7176 (which position
is a function of the weight of the user).
[0045] By the same token, the suppression of all armrests and armpads likewise offers greater
accessibility and improved drivability for the wheelchair user.
[0046] In the illustrated embodiment, the backrest 20 further comprises a backrest trim
(or backrest upholstery) 25 that encloses part of the backrest frame 21, as well as
a (first) cushion member 26 that is provided in the upper backrest portion of the
backrest 20 to support a corresponding upper portion of the wheelchair user's dorsum.
Also provided, in the illustrated embodiment, is an optional cushion belt 27 that
carries an additional cushion member 27A that is designed to provide additional support
for the wheelchair user's dorsum. Elements 25, 26, 27, 27A are of relevance insofar
as they are used to provide adequate support for the wheelchair user's dorsum. These
elements 25, 26, 27, 27A can be designed and formed in a variety of ways so as to
shape and adjust a profile of the backrest 20 to ensure optimal comfort for the wheelchair
user. For instance, while Figures 1A-1B and 2A-2E show that the lower portion of the
backrest 20 sits frontward of the upper backrest portion, Figures 8A-8B show an alternate
backrest 20*, the profile of which is such that the lower backrest portion forms a
recessed area 20A* facing a lower portion of the wheelchair user's dorsum. This helps
accommodating different wheelchair user's morphologies, providing space for the circulation
of air if need be and for accommodating for different user morphologies (see Figures
8A and 8B which schematically illustrate a person with an apple-shaped morphology
and a person with a pear-shaped morphology respectively). Figure 8A-8B further illustrate
that one can play with the shape of the cushion members 26*, 27A* to adjust the backrest
profile to the user's morphology.
[0047] Also visible in Figures 1A-1B and 2A-2E is a rolling support structure 60, including
a plurality of (here four) rolling elements 61, 62 provided at a terminal end of corresponding
support members 610, 620 (see e.g. Figure 2E), which rolling support structure 60
is preferably provided at a rear portion of the wheelchair 1, namely at a rear portion
of the wheelchair chassis 30. The purpose of this rolling support structure 60 will
be detailed later with reference to Figures 5A-5D.
[0048] In accordance with another aspect of a preferred embodiment of the present invention,
the wheelchair 1 is further provided with a pair of removable front canes 70 that
are supported into corresponding sockets 370 provided on the wheelchair chassis 30
next to a front part of the seating area 10. This pair of removable front canes 70
can take at least a first position (as depicted in Figures 1A-1B and 2A-2E) in which
the removable front canes 70 act as transfer aid devices to assist the wheelchair
user in raising up from or, conversely, sitting onto the seating area 10 of the wheelchair
1. As illustrated in Figures 1A-1B and 2A-2E, the front canes 70 each preferably exhibit
a handle portion 70a that is oriented frontward, in the depicted first position of
the front canes 70. Further details will be provided later in respect of these front
canes 70 with reference to Figures 9A-9C.
[0049] Figure 3A is a perspective view of the wheelchair 1 as seen from the same perspective
as Figure 2A, where the seat upholstery 15, backrest trim 25 and wheelchair cushions
26, 27, 27A have been omitted. Figure 3B is likewise a perspective view of the naked
wheelchair 1, stripped of elements 15, 25, 26, 27, 27A, as seen from the right-hand
side, like Figure 2D. By the same token, Figure 3C is a perspective view of a cross-section
of the naked wheelchair 1 as seen from the same perspective as Figure 3B, which cross-section
is taken along the same median plane A-A as depicted in Figure 2C.
[0050] Components that have already been described in connection with Figures 1A-1B and
2A-2E will not be discussed again. One will mainly focus on the backrest frame 21
and wheelchair chassis 30 that are now more clearly visible.
[0051] Turning first to the wheelchair chassis 30, one can more clearly see the rigid configuration
of the wheelchair chassis 30 with its two side frames 310 and cross members 301, 302,
303 interposed therebetween an ensuring the structural integrity and rigidity of the
wheelchair chassis 30.
[0052] In the illustrated example, one can more clearly see that the sockets 370 designed
to provide support for the front canes 70 are preferably formed in corresponding lateral
extensions 375 (also visible in Figures 1A-1B and 2A-2E) on either side of the wheelchair
chassis 30. These lateral extensions 375 can advantageously be an integral part of
the cross member 301, thus ensuring optimal bearing for the load that could be applied
via the front canes 70.
[0053] Also visible in Figures 3A-3C are two rear wheel supports 340 that are secured to
the wheelchair chassis 30 (namely to the side frames 310) and provide support for
each of the rear wheels 40. These rear wheel supports 340 - which are also partly
visible in Figures 1A-1B, 2A-2B and 2D-2E - define a position of a rear wheel axis
O of the rear wheels 40.
[0054] By way of preference, a front-to-rear position of each rear wheel support 340 along
the wheelchair chassis 30 (and therefore a front-to-rear position of the rear wheel
axis O) is adjustable. In the illustrated example, a vertical position of the rear
wheel axis O is likewise adjustable, namely thanks to the provision of a plurality
of (here four) mounting locations vertically along each rear wheel support 340. In
the illustrated example, the rear wheels 40 are mounted on the second mounting location
starting from the lower mounting location.
[0055] Adjustment of the front-to-rear position of the rear wheel supports 340 is achieved
by designing the chassis 30 so as to permit mounting of the rear wheel supports 340
at a plurality of distinct positions along each side frame 310. Only one position
is depicted in the illustrations, but it should be understood that the rear wheel
supports 340 could for instance be moved forward to one of multiple positions along
each side frame 310. To this end, a plurality of mounting holes (not shown) are provided
on a lower side of each upper frame member 310A (see Figure 3D) and corresponding
securing elements (such as screws or the like - not shown) are provided to secure
the upper end of each rear wheel support 340 to the relevant mounting holes provided
on the upper frame member 310A. At the lower end of each rear wheel support 340, there
is provided a claw member 345 (see Figures 3C and 3D) that is used to clip the lower
end of the rear wheel support 340 onto the lower frame member 310B of each side frame
310.
[0056] Mounting of the rear wheel supports 340 onto the wheelchair chassis 30 could be ensured
in any other suitable way and it suffices, in this context, that the support of the
rear wheels be such that a front-to-rear position of the rear wheel axis along the
wheelchair chassis can be adjusted.
[0057] Figures 3C, 3D and 4 (see also Figures 5A-5D) further illustrate how the rolling
support structure 60 is mounted onto the rear portion of the wheelchair chassis 30
in the context of this particular embodiment. As this is visible in the illustrations,
each rear wheel support 340 is designed in this particular embodiment to exhibit a
rear extension 340A projecting towards the rear of the wheelchair 1, which rear extension
340A is an integral part of each rear wheel support 340. Secured to this rear extension
340A is a support 360 carrying the relevant components of the rolling support structure
60, namely the lower and upper support members 610, 620 carrying the lower and upper
rolling elements 61, 62, respectively.
[0058] In the illustrated embodiment, it will be appreciated that the rolling support structure
60 is supported in such a way that any adjustment of the front-to-rear position of
the rear wheel axis O of the rear wheels 40 leads to a corresponding adjustment of
a front-to-rear position of the rolling support structure 60. More precisely, in the
illustrated example, the rolling support structure 60 is advantageously mounted on
the rear wheel supports 340 directly, and thus in a fixed relationship with respect
to the front-to-rear position of the rear wheel axis O.
[0059] Figures 3C, 3D and 4 further illustrate that the rear cross member 303 is interposed
between the rear wheel supports 340 (namely between the rear extensions 340A) and
thus likewise follows any adjustment of the front-to-rear position of the rear wheel
axis O. In other words, the rolling support structure 60 could, by way of alternative,
be mounted on the rear cross member 303.
[0060] In the illustrated embodiment, the lower rolling elements 61 that are mounted at
a terminal end of the lower support members 610 can advantageously act as anti-tip
devices, i.e. devices preventing tipping of the wheelchair onto its back. The lower
rolling elements 61 and associated lower support members 610 could be fixedly secured
to the relevant supports 360 or be potentially foldable or retractable for storage
purposes.
[0061] On the other hand, the upper rolling elements 62 that are located at a terminal end
of the upper support members 620 are preferably mounted on the relevant supports 360
so as to be movable between at least a first position (as illustrated in Figures 1A-1B,
2A-2E, 3A-3D, 4, 5A and 5B), or storage/non-deployed position, and a working/deployed
position (as illustrated in Figures 5C and 5D) to provide rolling support for the
wheelchair 1 in an upright position in which the wheelchair 1 is titled back and supported
by the rolling support structure 60, which upright position is depicted in Figure
5D.
[0062] In the upright position depicted in Figure 5D, and with the backrest 20 folded frontward
onto the seating area 10, the wheelchair 1 exhibits a sufficiently small profile to
allow the wheelchair 1 to be rolled through narrow passages, such as doorways or elevators.
This is of substantial importance in the present instance as the wheelchair chassis
30 is preferably designed as a rigid chassis.
[0063] Furthermore, and as depicted in Figure 5D, in the upright position of the wheelchair
1, the rear wheels 40 do not rest on the ground and are lifted slightly above the
ground, thus allowing easy removal of the rear wheels 40 if need be, as the wheelchair
user is not obliged to lift the wheelchair himself to perform such task, which would
be too complicated and tiresome for the user. In that context, each rear wheel 40
is preferably mounted on the wheelchair chassis 30 by means of a quick-release mechanism,
not shown, but known as such in the art. Thanks to such an arrangement, removal of
the rear wheels 40 for e.g. transport purposes is greatly facilitated and can easily
be performed either single-handed or with both hands being freed for that task.
[0064] In the illustrated embodiment, all of the rolling elements 61, 62 are supported onto
the wheelchair chassis 30, but one could alternatively contemplate to support only
part of the rolling elements 61, 62 on the wheelchair chassis 30 (e.g. the lower rolling
elements 61 only), while the remaining part of the rolling elements 61, 62 (e.g. the
upper rolling elements 62) could for instance be supported on the backrest 20. With
such a configuration, the upper rolling elements 62 could be deployed to the working
position upon folding the backrest 20 onto the seating area 10.
[0065] In accordance with a particularly preferred embodiment of the invention, the rolling
elements 61, 62 are ball casters, which ensures omnidirectional rolling support for
the wheelchair in the upright position. Such ball casters are known as such in the
art, for instance from US Patent No.
US 5,455,988 A and US Patent Publication No.
US 2015/0113765 A1, the disclosure of both of which is incorporated herein by reference.
[0066] Turning back to Figures 3A-3C and 4, one can see the structure of the backrest frame
21 with its two back canes 210 supported onto the wheelchair chassis 30 at lower ends
thereof, as well as the push handle 215 that is secured to upper ends of the two back
canes 210. The push handle 215 may conveniently be secured to the upper ends of the
back canes 210 so as to be adjustable in height. Also visible (see Figures 3C and
4) is a pair of cross members 211 interposed between the two back canes 210 and providing
structural integrity to the backrest frame 21, which pair of cross members 211 are
adapted to receive a backrest panel 212 (such as e.g. a wooden panel) - which backrest
panel 212 has been omitted in Figure 4.
[0067] The backrest frame 21 is further shown in isolation in the illustrations of Figures
6A-6C. As illustrated, lower ends 210A of the back canes 210 are supported onto the
wheelchair chassis 30 and are separated by the aforementioned first width W1. The
back canes 210 are furthermore curved inwardly so that upper ends 210B thereof, in
the vicinity of the wheelchair user's shoulders, are separated by the second width
W2. In other words, the back canes 210 each exhibit an inwardly-curved section 210a
where the backrest frame 21 transitions from a lower frame portion (corresponding
to the lower backrest portion of backrest 20) to an upper frame portion (corresponding
to the upper backrest portion of backrest 20).
[0068] Looking at the backrest frame 21 from the side, as illustrated in Figure 6C, one
can note that the backrest frame 21 further exhibits an offset between the upper and
lower frame portions, the upper frame portion sitting rearward of the lower frame
portion. The upper and lower frame portions are preferably offset by a distance D1
ranging between 50 millimeters and 100 millimeters. This offset advantageously provides
more room to play with the backrest profile and incorporate varying sizes of cushions
as depicted e.g. in Figures 8A and 8B.
[0069] The backrest and backrest frame could be designed in any suitable way to match the
overall dimensional requirements mentioned above. Figures 7A and 7B for instance show
another wheelchair 1' in accordance with another embodiment of the present invention
having a backrest 20' comprising a backrest frame including two back canes 210' (which
could in essence be similar to the back canes 210 shown in Figures 3A-3C, 4 and 6A-6C)
with the difference that upper ends thereof are further curved rearwardly to form
a pair of push handles 215'.
[0070] A positive effect resulting from the aforementioned dimensional considerations regarding
the design of the backrest (besides providing better ergonomics and improving the
amplitude of arm movement) also resides in the overall improvement of the wheelchair
aesthetics and look. Indeed, the "slimmed" backrest design provides a far better general
look and feel to the overall wheelchair which appears visually less bulky than conventional
bariatric wheelchair. This is a non-negligible aspect for the relevant wheelchair
users. As a matter of fact, the backrest of the invention gives the visual impression
of a wheelchair that would be smaller than it actually is, which is a very positive
and important element for bariatric users.
[0071] Turning now to Figures 9A-9C, one will further discuss the relevance and usefulness
of the pair of removable front canes 70 that are supported in the corresponding sockets
370 provided on the wheelchair chassis 30, next to the front part of the seating area.
[0072] As already mentioned, the pair of removable front canes 70 can take at least a first
position, as depicted in Figures 1A-1B, 2A-2E, 9A and 9B, in which the removable front
canes 70 are oriented with the handle portion 70a facing frontward. In this position
the front canes 70 can be used by the wheelchair user as transfer aid devices to assist
the wheelchair user in raising up from or, conversely, sitting onto the seating area
10 of the wheelchair 1. By doing so, the wheelchair user applies load to the handle
portion 70a of the front canes 70, which ensures optimal support and stability for
the wheelchair user, the applied load being adequately distributed amongst the four
contact points between the ground and the wheels 40, 45.
[0073] The front canes 70 are advantageously adjustable in height with respect to the wheelchair
chassis 30 in order to accommodate for different user's morphologies, which can be
ensured by an adequate support of the front canes 70 into the relevant sockets 370.
[0074] As further illustrated in Figure 9C, the removable front canes 70 are preferably
reversible and can take at least a second position, opposite to the first position,
with the handle portion 70a facing rearward. In Figure 9C, the front canes are designated
by reference numeral 70' for the sake of differentiation. In this position, the front
canes 70' thus also act as forearm supports for the wheelchair user. This arrangement
is also beneficial in that, in the second position, the front canes 70' do not prevent
the user from getting closer e.g. to a table or desk.
[0075] The removable front canes 70 are preferably designed so as to be insertable from
above into the corresponding sockets 370, and can be removed entirely in case of necessity,
especially during transport of the wheelchair e.g. in the upright position depicted
in Figure 5D.
[0076] Figures 10A to 10C are respectively a perspective view and two cross-sectional views
of a wheelchair 1* in accordance with another embodiment of the invention. In Figures
10A to 10C, the wheelchair backrest has been omitted and could in essence be identical
to the backrest 20 of wheelchair 1.
[0077] The wheelchair 1* comprises a wheelchair chassis 30* that differs slightly from the
wheelchair chassis 30 of wheelchair 1, but likewise comprises two side frames 310*
and three cross members 301*, 302*, 303* interposed therebetween. One difference may
be noted in respect of the middle cross member 302* that is interposed between the
side frames 310* and connects both the upper and lower frame members thereof 310A*,
310B* in this other embodiment, rather than only the lower frame members.
[0078] The wheelchair chassis 30* likewise comprises a pair of rear wheel supports 340*
supporting the rear wheels 40 (here at the upper mounting location), which rear wheel
supports are secured to each side frame 310* between the upper and lower frame members
310A*, 310B* by means of adequate securing elements, including a claw member 345*
used to clip the lower end of the rear wheel support 340* onto the lower frame member
310B*. In this other embodiment, the rear wheel supports 340* are shown as being mounted
at a more forward position on the wheelchair chassis 30* compared to the previous
embodiment.
[0079] Each rear wheel support 340* likewise comprises a rear extension 340A* forming an
integral part thereof, which extension 340* is used to secure a support 360* carrying
the rolling support structure 60*. The rear cross member 303* is similarly interposed
between the rear wheel supports 340*, namely between the rear extensions 340A*.
[0080] Figure 10A illustrates that each support 360* can be pivoted about a vertical axis
so as to move the associated elements 61*, 610*, 62*, 620* of the rolling support
structure 60* between a retracted storage position (shown on the left-hand side of
Figure 10A) and a (partly) deployed working position (shown on the right-hand side
of Figure 10A). The rolling support structure 60* can thus be fully retracted to a
storage position behind and underneath the wheelchair 1* if need be.
[0081] Figures 10B and 10C respectively show the rolling support structure 60* in partly
and fully deployed configurations. In the partly deployed configuration, the lower
rolling elements 61* and associated supporting members 610* take a position where
they can act as anti-tip devices, as in the previous embodiment. In this first configuration,
the upper rolling elements 62* and associated supporting members 620* are not fully
deployed as they are not particularly exploited when the wheelchair 1* is being wheeled
normally on its front and rear wheels 40, 45. In the fully deployed configuration,
the upper rolling elements 62* and associated supporting members 620* are moved to
an upper, working position, much like the upper rolling elements 62 and associated
supporting members 620 of the previous embodiment. In this fully deployed configuration,
the wheelchair 1* can once again be tilted back to an upright position and be supported
by the rolling support structure 60* to allow displacement of the wheelchair in the
upright position. The rolling elements 61*, 62* are once again preferably ball casters,
which ensures omnidirectional rolling support for the wheelchair 1* in the upright
position.
[0082] Various modifications and/or improvements may be made to the above-described embodiments
without departing from the scope of the invention as defined by the annexed claims.
For instance, other elements could be contemplated in order to act as rolling elements
for the rolling support structure. Ball casters are particularly preferred in that
they ensure omnidirectional rolling support of the wheelchair in the upright position,
but a combination of more conventional casters could also be contemplated.
[0083] Furthermore, although the embodiments disclosed herein show wheelchairs equipped
with a backrest comprising a backrest frame and backrest trim enclosing at least partly
the backrest frame, other backrest configurations could be contemplated.
[0084] In addition, while the disclosed embodiments all relate to purely manual wheelchairs,
power-assisted means could additionally be provided to help, support or otherwise
assist propulsion of the wheelchair, including electric motors or the like.
LIST OF REFERENCE NUMERALS AND SIGNS USED THEREIN
[0085]
- 1
- wheelchair (first embodiment)
- 1'
- wheelchair (alternate embodiment
- 1*
- wheelchair (alternate embodiment)
- 10
- wheelchair seating area
- 15
- self-supporting seat upholstery
- 20
- (foldable) wheelchair backrest (first embodiment)
- 21
- backrest frame
- 210
- back canes (part of backrest frame 21)
- 210a
- inwardly curved section of back canes 210 (also preferably curved rearwardly)
- 210A
- lower end of back canes 210
- 210B
- upper end of back canes 210
- 211
- cross members (part of backrest frame 21)
- 212
- backrest panel (e.g. wooden panel - secured to cross members 210)
- 215
- push handle (part of backrest frame 21)
- 25
- backrest trim
- 26
- backrest cushion
- 27
- cushion belt for additional backrest cushion
- 27A
- additional backrest cushion
- 20'
- (foldable) wheelchair backrest (alternate embodiment)
- 210'
- back canes of backrest 20'
- 215'
- push handle (part of back canes 210')
- 20*
- (foldable) wheelchair backrest (alternate embodiment)
- 20A*
- recessed area in lower backrest portion of backrest 20*
- 26*
- backrest cushion
- 27*
- cushion belt for additional backrest cushion
- 27A*
- additional backrest cushion
- 30
- wheelchair chassis (first embodiment)
- 301
- front cross member (part of wheelchair chassis 30)
- 302
- central cross member (part of wheelchair chassis 30)
- 303
- rear cross member (secured to adjustable rear wheel supports 340)
- 310
- side frames (part of wheelchair chassis 30)
- 310A
- upper frame member (part of side frame 310)
- 310B
- lower frame member (part of side frame 310)
- 320
- backrest frame supports (part of wheelchair chassis 30)
- 340
- adjustable rear wheel supports (secured to wheelchair chassis 30)
- 340A
- rear extension of adjustable rear wheel supports 340 for securing rear cross member
303 and support 360
- 345
- claw members for securing lower end of adjustable rear wheel supports 340 to wheelchair
chassis 30, namely to lower frame member 310B
- 360
- support for rolling support structure 60 (secured to adjustable rear wheel supports
340 - first embodiment)
- 370
- sockets for front canes 70
- 375
- lateral extensions of wheelchair chassis 30 provided with sockets 370
- 30*
- wheelchair chassis (second embodiment)
- 301*
- front cross member (part of wheelchair chassis 30*)
- 302*
- central cross member (part of wheelchair chassis 30*)
- 303*
- rear cross member (secured to adjustable rear wheel supports 340*)
- 310*
- side frames (part of wheelchair chassis 30*)
- 310A*
- upper frame member (part of side frame 310*)
- 310B*
- lower frame member (part of side frame 310*)
- 340*
- adjustable rear wheel supports (secured to wheelchair chassis 30*)
- 340A*
- rear extension of adjustable rear wheel supports 340* for securing rear cross member
303* and support 360*
- 345*
- claw members for securing lower end of adjustable rear wheel supports 340* to wheelchair
chassis 30*, namely to lower frame member 310B*
- 360*
- support for rolling support structure 60* (secured to adjustable rear wheel supports
340 - second embodiment)
- 370*
- sockets for front canes 70
- 375*
- lateral extensions of wheelchair chassis 30* provided with sockets 370*
- 40
- rear wheels
- 41
- hand rims
- O
- rear wheel axis
- 45
- front wheels
- 46
- pivotable front wheel supports (or forks)
- 50
- footrests
- 60
- rolling support structure (first embodiment)
- 61
- (lower) rolling elements (e.g. ball casters) of rolling support structure 60 - also
acting as anti-tip members
- 62
- (upper) rolling elements (e.g. ball casters) of rolling support structure 60
- 610
- (lower) support members for lower rolling elements 61
- 620
- (upper) support members for upper rolling elements 62
- 60*
- rolling support structure (second embodiment)
- 61*
- (lower) rolling elements (e.g. ball casters) of rolling support structure 60* - also
acting as anti-tip members
- 62*
- (upper) rolling elements (e.g. ball casters) of rolling support structure 60*
- 610*
- (lower) support members for lower rolling elements 61*
- 620*
- (upper) support members for upper rolling elements 62*
- 70
- reversible front canes shown in first position, acting as transfer aid devices
- 70'
- front canes 70 shown in reversed position, acting as forearm supports
- 70a
- handle portion of front canes 70
- W1
- width of lower portion of backrest 20, 20', 20*, in the vicinity of the seating area
10 / distance separating lower ends 210A of back canes 210 (selected with consideration
of wheelchair user's nominal hip width)
- W2
- width of upper portion of backrest 20, 20', 20*, in the vicinity of the wheelchair
user's shoulders / distance separating upper ends 210B of back canes 210 (selected
with consideration of wheelchair user's nominal shoulder articulation width)
- WH
- wheelchair user's nominal hip width (preferably ranging between 500 millimeters and
800 millimeters)
- WS
- wheelchair user's nominal shoulder articulation width (preferably ranging between
400 millimeters and 600 millimeters)
- D1
- distance separating lower frame portion of backrest frame 21 (lower ends 210A of back
canes 210) and upper frame portion of backrest frame 21 (upper ends 210B of back canes
210 - selected with consideration of wheelchair user's dorsum morphology)
- P
- mounting location at which the backrest is supported onto the wheelchair chassis /
pivotal axis of backrest with respect to wheelchair chassis
- D2
- horizontal distance separating the rear wheel axis O of the rear wheels 40 and the
mounting location P
1. A wheelchair (1; 1*), in particular a manual wheelchair for bariatric or heavy-duty
use, comprising a wheelchair chassis (30; 30*), a seating area (10) provided on the
wheelchair chassis (30; 30*), a backrest (20; 20'; 20*) supported onto the wheelchair
chassis (30; 30*), as well as front wheels (45) and rear wheels (40) provided on the
wheelchair chassis (30; 30*) to allow wheeling of the wheelchair (1; 1*),
characterized in that the wheelchair (1; 1*) further comprises a rolling support structure (60; 60*) provided
at a rear portion of the wheelchair (1; 1*) to support the wheelchair (1; 1*) in an
upright position in which the wheelchair (1; 1*) is tilted back and is supported by
the rolling support structure (60; 60*) to allow displacement of the wheelchair (1;
1*) in the upright position, which rolling support structure (60; 60*) includes at
least three, in particular four, rolling elements (61, 62; 61*, 62*) providing rolling
support for the wheelchair (1; 1*) in the upright position.
2. The wheelchair (1; 1*) according to claim 1, wherein the rolling elements (61, 62;
61*, 62*) provide omnidirectional rolling support for the wheelchair (1; 1*) in the
upright position.
3. he wheelchair (1; 1*) according to claim 2, wherein the rolling elements (61, 62;
61*, 62*) are ball casters.
4. The wheelchair (1; 1*) according to any one of the preceding claims, wherein at least
part, especially all, of the rolling elements (61, 62; 61*, 62*) are supported onto
the wheelchair chassis (30; 30*).
5. The wheelchair (1; 1*) according to any one of the preceding claims, wherein, in the
upright position of the wheelchair (1; 1*), the rear wheels (40) do not rest on the
ground, each rear wheel (40) being preferably mounted on the wheelchair chassis (30;
30*) by means of a quick-release mechanism.
6. The wheelchair (1; 1*) according to any one of the preceding claims, wherein the rolling
support structure (60; 60*) is at least partly deployable between a storage position
at a rear portion of the wheelchair chassis (30; 30*) and a working position where
the rolling elements (61, 62; 61*, 62*) are fully deployed to provide rolling support
for the wheelchair (1; 1*) in the upright position.
7. The wheelchair (1; 1*) according to any one of the preceding claims, wherein the rolling
elements (61, 62; 61*, 62*) include at least a pair of lower rolling elements (61;
61*) that also act as anti-tip devices.
8. The wheelchair (1; 1*) according to any one of the preceding claims, wherein a front-to-rear
position of a rear-wheel axis (O) of the rear wheels (40) along the wheelchair chassis
(30; 30*) is adjustable and wherein the rolling support structure (60; 60*) is supported
in such a way that any adjustment of the front-to-rear position of the rear-wheel
axis (O) of the rear wheels (40) leads to a corresponding adjustment of a front-to-rear
position of the rolling support structure (60; 60*),
and wherein the rolling support structure (60; 60*) is preferably supported in a fixed
relationship with respect to the front-to-rear position of the rear-wheel axis (O).
9. The wheelchair (1; 1*) according to any one of the preceding claims, wherein the wheelchair
chassis (30; 30*) is designed as a rigid, non-foldable chassis and is made of lightweight
materials, in particular aluminum,
and wherein the backrest (20; 20'; 20*) is preferably foldable frontward onto the
seating area (10).
10. The wheelchair (1; 1*) according to claim 8, wherein the wheelchair chassis (30; 30*)
is designed as a rigid, non-foldable chassis,
wherein the wheelchair chassis (30; 30*) comprises side frames (310) provided on left
and right sides of the wheelchair chassis (30; 30*), each comprising a rear wheel
support (340) to support a corresponding one of the rear wheels (40) at a position
defining the rear-wheel axis (O),
wherein a front-to-rear position of the rear wheel support (340) along each side frame
(310), and therefore the front-to-rear position of the rear-wheel axis (O), is adjustable,
and wherein the rolling support structure (60; 60*) is supported in a fixed relationship
with respect to the front-to-rear position the rear-wheel axis (O).
11. The wheelchair (1; 1*) according to claim 10, wherein the rolling support structure
(60; 60*) is supported directly onto the rear wheel supports (340) or onto a rear
cross member (303; 303*) of the wheelchair chassis (30; 30*), which rear cross member
(303; 303*) is interposed between the rear wheel supports (340).
12. The wheelchair (1; 1*) according to any one of the preceding claims, wherein the backrest
(20; 20'; 20*) exhibits a lower backrest portion supported onto the wheelchair chassis
(30; 30*), next to the seating area (10), the seating area (10) and lower backrest
portion having a first width (W1) that is selected to accommodate a wheelchair user's
hips,
wherein the backrest (20; 20'; 20*) further exhibits an upper backrest portion, in
the vicinity of the wheelchair user's shoulders, having a second width (W2) that is
smaller than the first width (W1), which second width (W2) is selected to liberate
space for movement of the wheelchair user's arms and shoulders,
13. The wheelchair (1; 1*) according to claim 12, wherein the first width (W1) is selected
to accommodate a wheelchair user's nominal hip width ranging between 500 millimeters
and 800 millimeters and wherein the second width (W2) is selected so as not to exceed
a wheelchair user's nominal shoulder articulation width ranging between 400 millimeters
and 600 millimeters.
14. The wheelchair (1; 1*) according to claim 12 or 13, wherein the backrest (20; 20';
20*) comprises a backrest frame (21) acting as structural element of the backrest
(20; 20'; 20*), which backrest frame (21) is shaped to exhibit lower and upper frame
portions supporting respectively the lower and upper backrest portions,
and wherein the backrest frame (21) preferably includes a pair of back canes (210;
210') having lower ends (210A) supported onto the wheelchair chassis (30; 30*) and
being separated by the first width (W1), which back canes (210; 210') are curved inwardly
so that upper ends thereof (210B), in the vicinity of the wheelchair user's shoulders,
are separated by the second width (W2).
15. The wheelchair (1; 1*) according to any one of the preceding claims, further comprising
a pair of removable front canes (70) supported into corresponding sockets (370; 370*)
provided on the wheelchair chassis (30; 30*) next to a front part of the seating area
(10), which pair of removable front canes (70) can take at least a first position
in which the removable front canes (70) act as transfer aid devices for assisting
the wheelchair user in raising up from or, conversely, sitting onto the seating area
(10) of the wheelchair (1; 1*), each removable front cane (70) exhibiting a handle
portion (70a) that is oriented frontward, in the first position,
and wherein the removable front canes (70) are preferably reversible and can take
at least a second position, opposite to the first position, with the handle portion
(70a) being oriented rearward, to act as forearm supports for the wheelchair user.