Note: Descriptions are shown in the official language in which they were submitted.
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The present invention relates to a foldable
invalid chair, or wheelchair.
Wheelchairs of this type are essentially
constituted by a seat supported by drive wheels which
are possibly provided with a hand-wheel, and by support
and steering wheels. The chairs generally comprise
footrests. They may possibly be foldable on themselves
so that they can be placed for example in a car boot,
thanks to cross bars pivoting with respect to each
other about a common axis lying at the center thereof.
The ends of these bars are fixed by a pivoting device
to the side walls of the chair or to structures fast
therewith.
These presently known wheelchairs are made
from a tubular structure, generally made of chromium-
plated metal. However, such a structure is heavy:
consequently, the invalid, or the person accompanying
him, often finds it difficult to fold then lift such
a wheelchair when this proves necessary.
It is therefore one of the objects of the
present invention to provide an invalid chair, or
wheelchair, which is both robust and as light as possible.
Another object of the invention if to provide
such a wheelchair which is simple and reliable to
fold and unfold.
It is a further object of the invention
to provide a wheelchair of this type at a relatively
moderate cost.
According to the present invention, there
is provided:
a foldable invalid chair comprising:
- two;lateral sides;
- a driving wheel and a steering wheel
carried by each of said sides;
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- means for holding said lateral sides
apart and for folding the chair; and
- a seat fixed to each of said sides;
wherein said two lateral sides and said two driving
wheels are of a composite material comprising two
walls made of a filamentous armature embedded in an
organic resin material, said walls being joined together
with a cellular material.
Preferably, the cellular material is a
foam or a material of honeycomb structure.
Preferably, the holding means comprise
two pairs of polygons, said polygons of each pair
being articulated at one of their ends to each other
and articulated at the other end to one of said lateral
sides respectively, each polygon being of said composite
material.
- Preferably, the two polygons of each pair
- of polygons are connected together with hinge means,
the hinge means of one pair of polygons are connected
to those to the other pair of polygons by means of
a bar, and a device is provided for blocking the hinge
means of one of said two pairs of polygons so that
the two polygons of each pair of polygons are in line
with each other.
A preferred embodiment of the invention
will be more readily understood on reading the following
description given as example, without limitative manner,
with reference to the accompanying drawings, in which:
Fig. 1 shows a schematic side view of an
invalid chair according to the present invention.
Fig.~2 is a rear view of this same chair,
and
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Fig. 3 is a schematic view from underneath of the chair shown
in Fig. 2.
Referring now to the drawings, the following description refers
to an invalid chair in unfolded position, i.e. when used by an invalid.
Such a wheelchair comprises side elements on each of its sides
and, for reasons of convenience, the major part of the specification will
refer only to one of these side elements.
Thus, side element I comprises a base part 2, a front vertical
part 3 and a rear vertical part 4.
Each side element I is constituted by two walls, or skins, made
of a composite material, coupled together so as to define a space adapted
to be filled with a cellular material such as a foam or a material of honey-
comb structure.
The front vertical part 3 is extended forwardly by a foldable
15 footrest 5 and downwardly by a support and steering wheel 6.
Drive wheels 7 are each mounted on a pin 8 passing through the
rear vertical part 4, in manner known per se, and possibly comprise on
their outer part a handwheel 9 of which the distance from the wheel may
vary as the invalid wishes.
These drive wheels are obtained by coupling together two half-
wheels 7a and 7b which are shown schematically in Fig. 2 (the wheel being
schematically shown in section along a spoke).
According to a preferred embodiment of the invention, this invalid
chair also comprises means for folding and unfolding it and for maintaining
25 the two side elements in spaced apart relationship.
These means comprise at least one assembly composed of two
polygons 10 and 11 which are articulated on each other, on the one hand,
and each on a side element, as shown in Fig. 2, as well as other means
known per se cooperating with this assembly.
This assembly is for example disposed perpendicularly between
the two rear vertical parts 4 and at a level lower than that of the seat.
In this way, each polygon is articulated on the one hand on the corresponding
rear vertical part and, on the other hand, with the other polygon preferably
along a common side.
This assembly of two polygons may also be made of a composite
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material.
The composite material used for making different elements of
an invalid chair according to the present invention may be the same for
all or different as a function of the specific stresses on each element.
5 In general, for the walls, or skins, of these elements, a composite material
of filamentary structure is used, whilst the space between these walls
is filled with a composite material of cellular structure. The composite
material of filamentary structure is constituted by a filamentous armature
(carbon, polyamide, glass, etc... fibers) embedded in an organic material
10 (polyester, epoxy, acrylic, etc... resin). The composite material of cellularstructure is generally a polyurethane or epoxy foam, for example, or a
material of honeycomb structure. This composite material generally has
a thickness of between I and 2 cm. For example, each side element I has
a thickness of about 1.5 cm and is formed by two walls, or skins, each
5 0.075 cm thick, connected together by a material of honeycomb structure
of which the alveolar cells have horizontal generatrices parallel to the
pins 8 of the drive wheels.
In the present embodiment, this invalid chair comprises two assem-
blies each of two polygons 10, 11 and 12, 13. The second assembly is disposed
20 at a level lower than that of the seat and perpendicularly between the
front vertical parts 3.
These polygons are trapeziums which are articulated by their
large base on the corresponding vertical part of the corresponding side
- element and by their small base on each other.
In this way, the polygons of each assembly can be folded on them-
selves thanks to hinges 14 and 15 respectively, disposed substantially at
the centre of each assembly.
These means for maintaining the side elements I in spaced apart
relationship and for folding the wheelchair, further comprise, according
30 to this embodiment, a bar 16 parallel to the side elements I and connecting
the hinges for articulation of the polygons of each assembly with each
other, as well as a device 17 for blocking one of these hinges (hinge 14
in the present example) so that the two polygons of each assembly are
in line with each other.
An invalid chair according to the present invention naturally also
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comprises all the elements usually found in such a wheelchair: in particular,
arrn-rests 18 and handles 19 disposed on the vertical part 4 to enable a
person accompanying the invalid to push and steer the wheelchair.
