EP1762210A1 - Foldable wheelchair frame and wheelchair - Google Patents

Abstract

The wheelchair chassis consists of two rigid side frames (1, 2) linked by crossing bars (8) connected by a pivot (12) with a vertical axis. Each bar has one end hinged to a side frame upright (6), and the other connected by horizontal sliding joints (9, 10) to the opposite frame. The two frames have upper and lower bars, while locking levers fix the chassis in the deployed position. An independent claim describes a chassis with side frames having one lengthwise bar each.

Description

The majority of folding wheelchairs that are known generally comprise a frame with one or more pairs of braces articulated on one another forming a parallelogram system deformable in a vertical plane.

This kind of chairs has several disadvantages. In particular, when the chair is folded, the size of the braces, which depending on the size of the chair protrude above the level of the armrests, prevents the folding of the backrest, which does not facilitate the transport of the chair and requires packaging of big size. On the other hand, the difficulties of operating the chassis constitute an obstacle to its use in certain circumstances. In particular, when folding the chair, this type of frame does not allow its sides to remain parallel. Although the flanks are found parallel at the end of folding, they are not during folding, which implies a tension of the backrest lining and a hard spot during the folding or unfolding phases of the chair.

This type of deformable parallelogram chassis comprises moving parts, some of which are only occasionally in contact with each other. The contacting of these parts during closing or opening movements of the chair can sometimes cause rapid wear or deterioration of the object, whose life can be shortened. In addition, it is not possible to design a production of standardized chassis, usable indifferently for different widths of chair.

The object of the present invention is to design a principle of realization of foldable wheelchairs frame allowing the manufacture and the marketing of foldable wheelchairs not having the defects mentioned above.

For this purpose, while known foldable wheelchairs frames comprise sets of braces articulated on horizontal axes, the present invention proposes in particular assemblies with pairs of braces articulated around vertical axes.

More particularly, the present invention relates to a foldable wheelchair frame as defined in claim 1. It also relates to a foldable wheelchair as defined in claim 6.

Other important features of the invention are defined in the dependent claims.

• la fig. 1 est une vue en perspective simplifiée d'une première forme d'exécution du châssis selon l'invention, en position dépliée,
• les fig. 2 et 3 sont des vues en plan de dessus du châssis de la fig. 1, dans des positions respectivement semi pliée et entièrement pliée,
• les fig. 4, 5, et 6 sont des vues en perspective montrant un fauteuil roulant utilisant le châssis des fig. 1 à 3, dans des positions respectivement ouverte, semi pliée et entièrement pliée,
• les fig. 7 et 8 sont des vues en perspective d'une structure de fauteuil roulant avec une deuxième forme d'exécution du châssis selon l'invention, dans des positions respectivement dépliée et semi pliée,
• la fig. 9 est une vue en perspective d'une structure de fauteuil roulant avec une troisième forme d'exécution du châssis selon l'invention en position dépliée,
• la fig. 10 est une vue en perspective d'un fauteuil roulant utilisant la première forme d'exécution du châssis selon l'invention avec un système de verrouillage à deux biellettes articulées sous le siège, le fauteuil étant en position semi pliée,
• la fig. 11 est une vue schématique en perspective montrant en position semi pliée le châssis selon la première forme d'exécution avec un système de verrouillage à biellettes, articulées entre la liaison coulissante des croisillons et un montant des flancs, et
• la fig. 12 illustre un exemple de conditionnement possible pour le transport d'un fauteuil roulant selon la présente invention.

The peculiarities and advantages of these various possible embodiments within the scope of the invention will emerge from the following description and comments, describing several embodiments by way of example only with reference to the drawings.

• fig. 1 is a simplified perspective view of a first embodiment of the frame according to the invention, in the unfolded position,
• figs. 2 and 3 are plan views from above of the frame of FIG. 1, in respectively semi-folded and fully folded positions,
• figs. 4, 5, and 6 are perspective views showing a wheelchair using the frame of FIGS. 1 to 3, in positions respectively open, half folded and fully folded,
• figs. 7 and 8 are perspective views of a wheelchair structure with a second embodiment of the frame according to the invention, in positions respectively unfolded and semi-folded,
• fig. 9 is a perspective view of a wheelchair structure with a third embodiment of the frame according to the invention in unfolded position,
• fig. 10 is a perspective view of a wheelchair using the first embodiment of the frame according to the invention with a locking system with two links articulated under the seat, the chair being in the half-folded position,
• fig. 11 is a schematic perspective view showing in a semi-folded position the frame according to the first embodiment with a locking system with rods, articulated between the sliding connection of the braces and an amount of the flanks, and
• fig. 12 illustrates an example of possible packaging for the transport of a wheelchair according to the present invention.

The simplified chassis shown in FIGS. 1 to 3 is a robust and rigid construction using prefabricated elements easy to work. Each of the flanks 1 and 2 consists of rigid bars, for example metal, especially steel or light metal tubes preferably assembled by welding, although other known assembly methods can also be envisaged. The upper 3 and lower 4 bars of each side are rigidly connected to the front and rear uprights 5, 6, and intended to work in a horizontal position. The rear uprights 6 serve as guiding bushings or connecting yokes 7 pivoting on them and each of which is fixed the rear end of a spider 8 whose front end is secured to a movable sliding linkage 9 along the other side. The braces 8 and their connection devices with socket 7 at one end and 9 at the other end represent an essential part of the frame described. Each upright 9 is connected, at its upper and lower ends, by pivoting articulations of vertical axis with two slides 10 and 11 being able to move along the upper and lower bars 4 of the sidewalls 1 and 2. This gives the structure of fig. 1 which we understand that it can be more or less folded as shown in Figs. 2 and 3 by simply sliding the elements 10 and 11 linked by pivoting to the uprights 9 on the bars 3 and 4. The assembly is such that the braces 8 pass one above the other. They are preferably connected by a pivoting device 12 of vertical axis as shown in FIGS. 1 and 2, the latter representing the chassis in the semi-folded position, while FIG. 3 shows a fully folded position reachable by an adequate conformation of the device 12, for example with extractable pivot rod. The structures of the various elements described may be chosen differently depending on the intended use. In particular, the slides 10, 11 are not necessarily tubular, they can also be trough-shaped. It is also noted that the device 12 can be arranged externally to the bars or tubes of the braces 8, which avoids weakening their rigidity by holes.

The use of the frame of FIGS. 1 to 3 for the construction of a wheelchair is illustrated in FIGS. 4 to 6. The structural elements 3, 4, 5 and 6 of the flanks 1 and 2 and the connecting uprights 9 of the crosspieces 8 are recognized. A rigid seat plate 13, with a central longitudinal articulation, fixed by its longitudinal edges on the bars 3 of the flanks 1 and 2, keeps the braces 8 in the spread positions when the chair is unfolded as shown in FIG. 4, thus ensuring the locking of the chair in the unfolded position. Of course, a security locking device of the seat plate in the locked position can be added. The longitudinal joint may take the form of a system of hinges placed under the elements of the seat plate. The armrests 14 and the side walls 15 are rigidly fixed to the bars 3 while the two parallel handles 16 are mounted at the rear end of the bars 3 beyond the uprights 6, so as to allow their folding in the folded or unfolded position. Between the risers of the handles 16, one can naturally provide the installation of a flexible backrest, for example textile, or rigid with a possibility of folding when the wheelchair in the folded position. The steerable front wheels 17 and the rear carrying wheels 18 are mounted via their hubs on brackets 19 and 20 which are attached to appropriate elements integral with the frames of the sidewalls 1 and 2. It can be seen that the consoles 19 of the front wheels have forks pivoting on vertical axes at the front of the uprights 5. A footrest 21 is further provided on each side 1 and 2 so as to fold forward of the wheels 17 when the chair is in the unfolded position (Fig 4). An important advantage of the described construction is the ease and safety offered for the passage from the unfolded position to a semi-folded position, for example for crossing a path constriction, or at the fully position folded, for example for boarding in another vehicle or for a simple trip.

Figs. 7 and 8 also illustrate a construction of a wheelchair with two rear carrying wheels 22 and two steerable front wheels 23. However, the carrying frame of this chair is of a simpler and lighter design than in the first form of execution while allowing the same applications. This frame, designated generally by 24, comprises two sidewalls each formed with a single structural element in the form of a horizontal rigid bar 25. The latter has, at the rear end, a pivoting articulation of vertical axis for a rear end of a spider 27 and, at the front end, an upright 28 rigidly connected to the bar 25, oriented vertically and guiding one of the steerable front wheels 23. A second rigid upright 29 is disposed at a predetermined location of the length of the bar 25. It extends vertically and carries the hub 30 of one of the wheels 22. Finally, between the uprights 28 and 29, each bar 25 carries a sliding connection 31 which can be of the same type as the slides 10 and 11 and on which pivots one end of a cross 34 constituting the second cross of the pair ensuring the operation of the frame. The braces 27 and 34 thus pivot on the pivot links 26 at the rear ends of the flanks 25 of the frame. They are articulated one on the other by a pivoting connection 33 similar to the link 12 of the first embodiment so that the unfolding and the folding of the chassis are carried out without difficulty and gradually, the two sides being guided while remaining parallel to each other and the links 31 sliding on the bars 25. The uprights 29 carry at their lower end consoles with the axles 30 of the wheels 22. At their upper end they will carry structural elements for the seat, side sides, armrests, handles and other accessories necessary for this kind of furniture. Fig. 8 shows the chair in a semi-folded position. The transition from the unfolded position to the semi-folded position being very easy, this intermediate position can be used momentarily while the occupant remains seated, for example to cross a narrow passage.

A heavier and more massive embodiment of the frame according to the invention is shown in FIG. 9. Here, the two sides 35 each formed of a rectangular frame are connected by two pairs of braces 36, 37 and 38, 39 intersecting on the same axis, at a distance from each other, each pair of braces being mounted on a pivot axis 40, 41. Whatever the folded, semi-folded or open position of the frame, the common axis of the two pairs of braces is always located in the middle between the flanks and parallel to their planes. The distance between the two pairs of braces may be greater or less depending on the desired performance for the chair. The two parallel flanks 35 comprise, as in the embodiments already described, auxiliary elements for mounting two steerable front wheels and two load wheels (not shown). The folding system uses here the two pairs of braces 36, 37 and 38, 39 whose pivot axes 40 and 41 are superimposed. Amounts 42, 43 and 44, 45 are rigidly fixed to the ends of the crosspieces so that the entire system forms two rigid frames intersecting on the pivot axis 40, 41. In each of these frames, one of the uprights forms the sliding connection device of the frame on the bars respectively upper and lower of a side while the other upright is a pivoting joint, using a socket or clevis on the rear pillar of the other side. This gives a layout quite similar to that of the first embodiment, shown in FIG. 1, extremely simple and robust, very easy to handle, even for furniture or vehicles that have to withstand heavy loads.

Fig. 9 also shows that the two uprights 43 and 44 carry halfway up the outer elements in the form of rotating handles 46, 47. They represent the control of a locking means of the sliding connections of the pairs of braces on the upper and lower bars flanks. In fact, the frames of the various exemplary embodiments can be equipped with locking systems as desired in the example of FIG. 9.

Other examples of locking systems will now be described with reference to FIGS. 10 and 11. Thus, the two flanks 48 and 49 of the frame of FIG. 10, whose structure is similar to that of the first embodiment with a single pair of braces, are connected to the front of the frame by an articulated structure formed of two links 50, 51, hinged at one end on the uprights front of each of the flanks 48, 49 and at the other end to one another so as to form a compass, so that in the semi-folded or fully folded position of the frame, the compass is open while in unfolded position the two rods are locked in the extension of one another. This system, which can be doubled at the rear of the chair, supports the seat 52. The backrest 53 is also shown in FIG. 10. Alternatively, the rod system shown in FIG. 10 could be replaced by a system with several rods bracing each other keystone. A lever control would then allow the user to modify himself the width of the chair. The bracing elements could have a certain thickness and be connected by a flexible band.

Another embodiment of a locking system is schematically shown in FIG. 11. A frame similar to that of fig. 1 comprises two parallel flanks 54 and 55 connected by two braces 56, 57 articulated on a central pivot 58. The sliding connections 59 and 60 allowing the mobile ends of the braces to move along the sidewalls 54 and 55 are subjected to a stress of limitation of their movements by a system of articulated links 61, 62 whose operation is clear from FIG. 11. When the frame is in fully open position, the links 61, 62 are tensioned and any subsequent movement of the slides is prohibited until the beginning of a folding of the frame. Although the rods 61, 62 have been shown only on the sidewall 54, this locking system could also be mounted on both sidewalls 54 and 55.

The realization of the frame with braces articulated around vertical axes allows to provide a foldable backrest on the front because, when the frame is folded, it does not overflow over the armrests. A chair made with this arrangement allows to offer unparalleled compactness so far for its transport. Indeed, the only incompressible, non-removable or non-folding elements of a wheelchair being the wheels, the arrangement of the chair according to the present invention, with horizontal braces, folding backrest on the front and quick release wheel of the type. known, can be easily stored and transported in a box of almost square shape with dimensions barely larger than the diameter of the wheel, as illustrated in FIG. 12.

In addition, the design of the articulated frame articulated around vertical axes allows the realization of chassis standardized for different widths of armchairs.

As can be seen, numerous alternative embodiments are possible on the basis of the design of the chassis object of the invention, as described above, and the skilled person may realize others without departing from the scope of the invention. the invention.

Thus, all the examples described are illustrated with adjustable wheels fixed to the front of the chair, the load wheels being at the rear. But of course, the steerable wheels can be arranged at the rear, the load wheels being at the front of the chair. Similarly, it is possible to have the load wheels in the center of the wheelchair with steerable wheels at the front and rear.

Claims (8)

Foldable wheelchair frame, characterized in that it comprises two rigid and non-deformable sidewalls (1, 2; 25; 35; 48,49; 54,55), a bar structure forming at least one pair of crosspieces (8; 27, 34; 36, 37, 38, 39; 56, 57), and articulated connections between the ends of the braces and flank members, said links being, for each spider, at a horizontal sliding end (9, 10, 11; 31; 43, 44; 59, 60) on one member of a sidewall and at the other end pivoting vertically on an element of the other side (7; 26; 42 , 45). Chassis according to claim 1, characterized in that the two bars of each pair of braces are connected to each other by a pivoting articulation of vertical axis (12; 33; 40,41; 58). Frame according to claim 1, characterized in that the flanks are rigid frames (1, 2; 35; 54, 55; 48, 49) having two horizontal bars respectively upper and lower (3, 4) and two end uprights. (5, 6) secured to the horizontal bars, one of the uprights of each side constituting a guide member (6) for the pivotal connection of one of said braces. Chassis according to claims 1 and 2, characterized in that the flanks are structures with a single horizontal bar (25) intended to cooperate with a single pair of braces (27, 34), and in that they each carry a end of a vertical axis pivot connection (26) for one of the braces (27 or 34) of the pair and along the bar a sliding connection arrangement (31) receiving one end of the other spider (34 or 27). ) of said pair. Chassis according to any one of the preceding claims, characterized in that it comprises a link locking system (61, 62) or articulated spacer (50, 51) blocking the frame in the deployed position. Folding wheelchair comprising a frame according to any one of the preceding claims, characterized in that at each side there are connected supporting elements for at least one steerable wheel (17, 23), a carrier wheel (18, 22), a seat (13; 52) and a backrest (53). Armchair according to claims 6 and 5, characterized in that the seat is a flexible structure (52) associated with at least one system of articulated rods (50, 51) constituting said locking system. Armchair according to claims 6 and 5, characterized in that the seat is a structure composed of two rigid parts hinged to one another, said hinged portions constituting said locking system.

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