IE55704B1 - Invalid chair based on composite materials - Google Patents

Abstract

Invalid chair or wheel-chair based on composite materials comprising particularly a seat secured between two sides (1), each side comprising a drive wheel (7) providing with a handrail (9), a supporting and steering-wheel (6) and a foot rest (5). Both sides (1) and both drive wheels (7) as well as the foot rests (5) and means for holding the sides (1) spread apart and for holding said chair are made totally or partly with composite materials. [WO8501205A1]

Description

2 255704 The present invention relates to an invalid chair, or wheelchair, based on composite materials.

Wheelchairs of this type are essentially constituted by a seat supported by drive wheels which are possibly provided with a hand-wheel, 5 and by support and steering wheels. These 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 centre thereof. The ends of these bars are fixed by a pivoting device to the side walls of the chair 10 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 neces-15 sary.

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 is 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.

These objects as well as others which will appear hereinafter, are attained by a foldable invalid chair comprising: - two lateral sides ; 25 a driving wheel and a steering wheel carried by each of said sides ; - means for holding said lateral sides apart and for folding the cha ir ; and - a seat fixed to each of said sides .

According to the present invention, 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. 3 The cellular material is preferably a foam or a material of honeycomb structure.

The holding means advantageously comprise two pairs of polygons, said polygons of each pair being articulated 5 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.

The two polygons of each pair of polygons are preferably connected together with hinge means, the hinge means of one 10 pair of polygons are connected to those of the other pair of polygons by means of a bar, and a device is provided for blocking the hinge means of one of said pairs of polygons so that the two polygons of each pair of polygons are in line with each other. -)5 The invention will be more readily understood on reading the following description with reference to the accompanying drawings, in which: Fig. I 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 20 Fig. 3 is a schematic view from underneath of the chair shown in Fig. 2.

Referring now to the drawings, (he 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 ¢.

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 honeycomb 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 *i, in manner known ger 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 7j? 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 £er se cooperating with this assembly.

This assembly is for example disposed perpendicularly between the two rear vertical parts 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 5 material.

The composite material used for making different elements of an invalid chair at cording to the present invention may he the same for all or dilleicnt as a function of the specific stresses on each element.

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 cellular structure is generally a polyurethane or epoxy foam, for example, or a material of honeycomb structure. This composite material generally has a thickness of between 1 and 2 cm. For example, each side element 1 has a thickness of about 1.5 cm and is formed by two walls, or skins, each 15 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 assemblies 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 Uf 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 M 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 comprises all the elements usually found in such a wheelchair: in particular, arm-rests 18 and handles 19 disposed on the vertical part 4 to enable a person accompanying the invalid to push and steer the wheelchair.

Claims (5)

1. 7

2. 1. A foldable invalid chair comprising : t wo 1 aLeral s i des ; a driving wheel and a steering wheel carried by each of said sides ; - 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.

3. 2. A chair according to claim 1, wherein said cellular material is a foam or a material of honeycomb structure.

4. 3. A chair according to claim 1, wherein said lidding 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. A.- A chair according to claim 3, wherein 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 of 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.

5.- A foldable invalid chair according to claim 1, substantially as hereinbefore described with particular reference to and as illustrated in the accompanying drawings. F.R. KELLY & CO., AGENTS FOR THE APPLICANTS.