EP0699067A1

EP0699067A1 - Lifting device for a stand-up wheelchair and wheelchair using same

Info

Publication number: EP0699067A1
Application number: EP95913214A
Authority: EP
Inventors: Gérard BOBICHON
Original assignee: International Diffusion Consommateurs IDC SA
Current assignee: International Diffusion Consommateurs IDC SA
Priority date: 1994-03-18
Filing date: 1995-03-17
Publication date: 1996-03-06
Anticipated expiration: 2015-03-17
Also published as: EP0699067B1; US5772226A; ATE171061T1; WO1995025497A1; CA2163254A1; FR2717377B1; DE69504790D1; FR2717377A1; DE69504790T2

Abstract

PCT No. PCT/FR95/00330 Sec. 371 Date Mar. 25, 1996 Sec. 102(e) Date Mar. 25, 1996 PCT Filed Mar. 17, 1995 PCT Pub. No. WO95/25497 PCT Pub. Date Sep. 28, 1995A wheelchair having a lifting device wherein the seat and the footrest are independent from each other and are mounted on the top ends of two deformable quadrilaterals extending upwards from the chassis and sharing a common moving portion, and wherein the raising and lowering control devices comprise a drive member interposed between the chassis and one of the moving members of one of the quadrilaterals, and suitable for controlling the displacement of said quadrilaterals between a stable folded state and a stable unfolded state.

Description

LIFT DEVICE FOR VERTICALIS AUTEUR WHEELCHAIR AND WHEELCHAIR USING TECHNICAL FIELD APPLICATION

The present invention relates to wheelchairs used by the handicapped and disabled and it targets, indifferently, folding or non-folding wheelchairs.

There is no question that wheelchairs have provided mobility for the disabled and disabled. These wheelchairs have, however, several drawbacks due to the fact that the users can only occupy a seated position, moreover, generally maintained for relatively long periods. In an attempt to remedy the drawbacks arising from this single possibility of use, various proposals have been made so that such armchairs are rendered vertical, in order to allow the user to be kept in a substantially upright position.

PRIOR ART

As a general rule, the proposals made involve an articulated structure comprising a backrest, a seat and a footrest. Such a structure is mounted articulated generally by the seat on a horizontal front axis and perpendicular to the vertical plane of symmetry of the chassis. A motor means is interposed between the chassis and the structure to allow the raising or lowering of the latter, thus able to occupy a folded position called seat and an unfolded position called verticalized. The drive member can be either manual, electric or other.

To illustrate this prior technique, it is possible to cite, among others, French patent 69-35042, German application 26 25 045 or even French patent 82-11713.

These various proposals certainly meet the objective of verticalization and, in this sense, have brought undeniable well-being to users. The structural proposals which have been formulated by the prior art generally rely on the articulation of the articulated structure on a horizontal frontal axis and perpendicular to the vertical plane of symmetry of the chassis and resting on the latter. Such an organization has the effect, in the verticalization function, of transferring the articulated structure and the verticalized user to the front part of the chair with as a consequence an increase in the load on the front wheels and a reduction in that of the rear wheels.

Such a consequence introduces a factor of instability, given that the support polygon is not loaded equally. This is why, as a rule, additional support points are provided to stabilize the chair in the vertical state of the articulated structure. Such additional support points are frequently, not to say always, constituted by casters, skates, crutches or even by heels which are provided for construction in the extension of the footrest, so as to rest on the ground in the verticalized state of the articulated structure.

If such a proposal, in the general sense, makes it possible to confer a certain factor of stability and security for users, on the other hand, it poses an insurmountable problem when it is necessary to take into account the desire to make wheelchairs, mobile, even in the verticalized state of the articulated structure. Such a trend corresponds to the desire of users to be able to recover, by such a means, a perfectly understandable form of life and autonomy.

Being able to reconcile such a wish with current technology seems incompatible with the search for great stability and, where appropriate, good handling. In an attempt to remedy such a double requirement, different construction proposals have been made by the prior art. It has thus been proposed, for example as illustrated by US Pat. No. 3,907,051, to place the motorization means in a rear box, so as to ballast the wheelchair to lower the center of gravity and balance the frontal overload which is established in the vertical position.

Such a proposal must certainly make it possible to respond in part to the problems of stability and security, but does not appear to be usable in all configurations and with all the energies likely to be used to ensure the motorization of the wheelchair.

Furthermore, such a proposal hardly appears incompatible with the desire to have a wheelchair which is always foldable to allow its easy transport, in particular in a motor vehicle.

The prior art knows a different proposal from the application WO 82-01314 which recommends mounting on the chassis of the wheelchair an articulated structure which, when passing into the verticalized position, experiences a relative back-displacement having the effect of placing the assembly of the structure and of the user substantially in alignment with the vertical axis passing through the center of the support polygon which constitutes or which the chassis defines.

In this way, the general verticalized load is distributed with respect to the support polygon and gives the latter a certain stability making it possible to envisage the motorization and the movement of the wheelchair, even in this state of verticalization.

Examination of the proposal nevertheless reveals that the technology proposed by application WO 82-01314 is relatively complicated and implements a high number of points of articulation between the various elements of the articulated structure and numerous connections by links connecting the structure to the chassis.

These numerous articulation links weaken the construction, weigh down the whole and require constant maintenance to prevent any local malfunction from resulting in defective folding or unfolding, which can lead to accidents.

In addition, a large part of these joints are placed in the front part of the chair and in particular in a frontal area at the seat with the effect of hampering access to the latter for a handicapped person or an invalid.

In addition, the fact of automatically causing the retro-displacement of the articulated structure implies to move the footrest in the same direction, from a frontal position corresponding to a seated state to a corresponding retracted position. to a verticalized state.

This displacement in the antero-posterior direction during the two movements implies leaving sufficient passage clearance for the footrest and poses a difficult problem of adaptation on the chassis of front wheels, pivoting and directional, generally more smaller diameter than the rear load-bearing wheels, as is most frequently adopted for wheelchairs.

This subjection complicates the manufacture of the chair, as well as the realization of the latter in a space gauge in particular transverse, compatible with the various fields of use, such as domestic use, for which a passage between the legs of standard door frames must be made possible.

The number of articulations and the large number of connecting rods also have the effect of considerably weighing down the equipped wheelchair which becomes less easy to handle, while requiring from the user a greater physical expense when the movement of the wheelchair n is not insured or assisted by an on-board motorization.

The present invention aims to remedy the above drawbacks by proposing new means of connection between an articulated structure and a stand-up wheelchair frame, such means, while allowing verticalization, moreover making it possible to cause, automatically and simultaneously to the verticalization phase, a retro-displacement of the articulated structure to center the verticalized load with respect to the support polygon and thus give the chair placed in such a state of use stability and security allowing mobility and the ability to manual or motorized movement, without any risk for the verticalized subject.

Another object of the invention is to provide support and articulation means which are simple, reliable, light and inexpensive, so as to make possible adaptation under the best conditions, without considerably weighing down the chair and rendering thus possible, if necessary, an adaptation on folding armchairs. STATEMENT OF THE INVENTION

To achieve the above objectives, the lifting device for a stand-up wheelchair is characterized in that - the seat and the footrest are independent of each other and are mounted on the upper ends of two deformable quadrilaterals , rising from the chassis and having a common mobile part, the lifting-lowering control means comprise a motor member interposed between the chassis and one of the mobile members of one of the quadrilaterals and capable of controlling the movement said quadrilaterals between a folded stable state corresponding to a so-called sitting position of the structure and an unfolded stable state corresponding to a so-called verticalization position of the structure in which the mass which the latter represents is substantially centered relative to the support polygon. The subject of the invention is also a stand-up wheelchair comprising an articulated structure linked to the chassis by the above means.

Various other characteristics will emerge from the description given below with reference to the appended drawings which show, by way of nonlimiting examples, embodiments of the subject of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic side elevation of a chair according to the invention.

Figure 2 is a front view, taken along the line II-II of Figure 1. Figures 3 and 4 are views similar to Figure 1, illustrating the chair in two characteristic positions. Figure 5 is a front view similar to Figure 2, but illustrating an alternative embodiment. BEST WAY TO REALIZE THE INVENTION

Figures 1 and 2 schematically show a wheelchair 1 comprising a chassis 2 consisting of a lower frame 3, for example formed by side members 4 joined by crosspieces 5 and 6. It goes without saying that this embodiment is not given as an example and schematically, for the sole purpose of lightening the representation while allowing the understanding of the subject of the invention. Thus, the chassis 2 is provided, in a usually known manner, with generally supporting, main and driving wheels 7 and with steering wheels 8, orientable by means of pivots 9. The wheels 8 are generally, but not necessarily, placed at the front part of the chassis 2, while the carrying wheels 7 occupy the rear part. The wheels 7 and 8 define, by the points of contact with the ground S, a support or support polygon through the center of which passes a vertical axis x-x '. The wheels 7 are mounted on the chassis 2 by means of bearings 10 and can advantageously be associated with motor members for reversible rotation drive 11, such as one or more electric motors capable of being powered from a source 12 on board and arranged on a console 13 placed between uprights 14.

The chassis 2 conventionally supports an articulated structure comprising a seat 20, a backrest 21 and a footrest 22. In a known manner, the articulated structure is organized so as to be able to occupy a stable, folded state, corresponding to a so-called sitting position, as illustrated in FIG. 1 and a stable, unfolded state, corresponding to a verticalization position, as illustrated in FIG. 4. In these two positions and by means known in the art and not shown , the articulated structure is able to support a disabled or disabled person in a seated position and in a vertical position respectively.

According to the invention, the articulated structure is organized so that the seat 20 is carried by the frame 2 by means of an articulation means 23 in the form of a deformable quadrilateral, such means being for example organized in two lateral assemblies 24. Each assembly comprises a rear articulated part or link 25 and a front articulated part or link 26 which are respectively mounted by axes 27 and 28 on the rear uprights 14 and on the longitudinal members 4. The upper ends of the articulated parts or connecting rods 25 or 26 carry the seat 20 by means of articulation axes 29 and 30 which are respectively placed substantially in the middle part of the underside of the seat 20 and in the front part of the latter. In the folded state, the part 25 extends from the uprights 14 towards the front, in a substantially horizontal direction, while the front articulated part 26 also extends towards the front but in an upward inclination from chassis 2.

The backrest 21 is mounted, according to the invention, by a hinge pin 31 on the rear part of the seat 20 and is linked to the latter by a hinge means 32 in the form of a deformable quadrilateral. The means 32 comprises a movable part which is common to the deformable quadrilateral 23.

The means 32 is for example constituted by an extension 21a extending downward from the backrest 21 and on which is articulated, by an axis 33, a movable part 34, such as one or two links linked by an axis 35 at the rear part or parts 25 constituting the deformable quadrilateral 23.

The mobile part 34 can also be organized into two lateral assemblies in the same way as the assemblies 24.

The footrest 22 is preferably constituted by two legs 40 each provided at the base of a sole 41. The two legs 40 are independent and devoid of articulation with the seat 20 and are carried by the frame 2 by by means of an articulation means 42, of the deformable quadrilateral type, preferably also organized like the other quadrilaterals in the form of two lateral assemblies. Each lateral assembly comprises a front part 43 articulated by an axis 44 on the chassis 2 and carrying the corresponding jamb by an upper articulation axis 45. Each lateral assembly also involves, for the constitution of the deformable quadrilateral, a common element with the quadrilateral deformable 23, such a common element being constituted by the front part 26 which is, in such a case, situated posterior to the front part 42. To assume this function, the front part 26 is provided, below its point of articulation 30 with the seat 20, an extension 46 on which is mounted the leg 40 by means of a hinge pin 47.

The front part 43 of each deformable quadrilateral 42 extends forwardly in a rising inclination between the frame 2 and the leg 40.

As shown in FIG. 1, the deformable quadrilateral system 23 is defined by the articulation points 27, 28, 29 and 30. The deformable quadrilateral articulation system 32 is defined by the articulation points 29, 31, 33 and 35.

The articulation system based on a deformable quadrilateral 42 is defined by the articulation points 28, 44, 45 and 47.

According to the invention, provision is made to provide the lifting device described above with a drive member 50 making it possible to pass the articulated structure from the position according to FIG. 1 to the position according to FIG. 4 and vice versa. Such a driving member 50 may be constituted by a manually controlled mechanism or, preferably, by an energy transformer, of the electric jack type, capable of being supplied from the source 12, in particular by means of a manipulator 51 accessible, for example on one of the removable or orientable armrests 52, fitted to the backrest 21 or the seat 20. The drive member 50 is interposed between the chassis 2 and one of the movable elements of one deformable quadrilaterals and preferably that 23 specific to the seat 20. In an appropriate example illustrated by FIG. 1, the motor member 50 is constituted by an electric actuator whose base is adapted to the chassis 2 and whose rod is, for example, articulated by an axis 53 on a crosspiece connecting the parts 25 of the two lateral assemblies 24.

In the case of adaptation of a manually controlled drive member 50, provision may be made to associate elastic compensators, such as gas cylinders, making it possible to relieve the load, in particular, during the unfolding of the articulated structure for to pass from the state according to figure 1 to the verticalized state according to figure 4.

Although this is not shown, the chassis 2 can be organized to reveal one or more stops 60 reserving a support for the articulated structure in position or in the folded state, by cooperating for example directly or indirectly with the seat 20 and / or one of the appropriate deformable quadrilaterals. In the state according to Figure 1, the articulated structure is in the folded position in a position such that the seat 20 is substantially horizontal and that the footrest 22 is arranged just in front of the front part of the chassis and of the transverse plane of the articulation pivots of the steered wheels 8.

When it is desired to control the change of state of the articulated structure to make it pass into a verticalization state, the motor member 50 is controlled, for example to ensure its extension stroke, so that it tends to lift the articulated elements 25 constituting the deformable quadrilateral 23 specific to the seat 20. The articulated elements 25 are thus required to pivot in the direction of the arrow fj (fig.3) on the axes 27 and cause the axis to move 29 along a circular path T, having the axis 29 at the center and the length of the elements 25 as their radius.

The movement of the axis 29 drives in the same direction the seat 20, the articulation axis 30 of which is displaced along a circular trajectory T ₂ having the axis 28 at its center and the length of the front part 26 as its radius. The constructive characteristics of the deformable quadrilateral 23 mean that the curves T, and T ₂ intersect at a point O "as illustrated in FIG. 3, so that the seat moved backwards is simultaneously subjected to relative pivoting in the direction of arrow f ₂ *

Simultaneously, the pivoting of the seat 20 causes the upward movement of the axis 31 which subjects the backrest 21 to a relative movement relative to the seat, although remaining by itself substantially in the same inclination. Such a characteristic is provided by the structure of the deformable quadrilateral 32.

The displacement along the curve T ₂ of the point 30 causes the displacement along the curve T ₃ of the articulation point 47 of the deformable quadrilateral 42, this trajectory T ₃ having as its center the articulation point 28 and for the radius the link portion 26 between this point and the axis 47. Via the legs 40, the articulation points 45 are displaced along a circular trajectory T ₄ , having the axis 44 for center and the length of the front elements 42 for radius.

This characteristic means that, in the intermediate phase and concomitantly with the movement in the direction of the arrow f ₂ of the seat 20, the footrest 22 is raised and back-displaced, as shown in FIG. 3. The measurement d elevation is conferred by the constructive characteristics of the deformable quadrilateral 42, such so that, when the soles 41 suφlombent the horizontal casing of pivoting of the front wheels 8, with their initial inclination, they are located at a height from the ground S greater than the diameter of the latter. In this way, the retro-displacement of the footrest 22 can be carried out freely whatever the orientation of the front steering wheels 8.

The characteristics of the deformable quadrilaterals are chosen by construction so that, after the displacement of the drive member 50 on its active stroke, the seat 20 and the backrest 21 are substantially placed in alignment at a slight inclination, while the feet 22 is located by retro-displacement included inside the support polygon defined by the wheels 7 and 8. In this so-called verticalization state, as shown in FIG. 4, it appears that the articulated structure is distributed as a whole on either side of the vertical axis x-x ', so that the load or mass which it represents alone and that which constitutes the verticalized subject are perpendicular to said vertical axis xx' and substantially at the center of the support polygon to give the chair brought into such a configuration, a stable state allowing movement via the wheels.

The constructive characteristic of the support and articulation means based on three deformable quadrilaterals has the characteristic of causing the relative displacement of the backrest, the seat and the footrest, along the paths Tj, T ₂ , T ₃ and T ₄ which are directed towards the rear part of the chair and thus generate a retro-displacement of the articulated structure to bring the latter from the seated position with an anterior tendency to a vertical position substantially centered on the axis x-x '.

Furthermore, as appears from the comparison of FIGS. 1, 3 and 4, the means according to the invention make it possible to significantly reduce the bulk in the anteroposterior plane of the chair in the verticalized position and to give it in this state a compactness. favoring evolutions.

A reverse operation to what has just been described is established when the member 50 is controlled to bring the articulated structure from the vertical position to the seated position illustrated in FIG. 1.

Figure 5 shows an alternative embodiment in which the quadrilaterals deformables are no longer organized in lateral sets such as 24, but in the form of a column by being grouped on either side of the anteroposterior plane of vertical symmetry P-P '.

INDUSTRIAL APPLICATION

The invention finds a particularly advantageous industrial application in stand-up armchairs which, moreover, offer a possibility of folding along a vertical, longitudinal plane of symmetry, so as to reduce their bulk in the transport phases, in particular in the automobile.

The invention is not limited to the examples described and shown since various modifications can be made thereto without departing from its scope.

Claims

1 - Lifting device for a stand-up wheelchair, of the type comprising a chassis (2) provided with wheels (7, 8) defining a support polygon and supporting an articulated structure comprising a seat (20), a footrest (22 ) and a backrest (21), a device comprising means for supporting and articulating the structure on the chassis and means for controlling the raising and lowering of said structure relative to the chassis, characterized in that - the seat and the footrests are independent of each other and are mounted on the upper ends of two deformable quadrilaterals (23, 42), rising from the chassis and having a common movable part (26),

- The means (50) for raising-lowering control comprise a motor member interposed between the chassis and one of the movable members of one of the quadrilaterals and capable of controlling the movement of said quadrilaterals between a folded stable state corresponding to a position said seat of the structure and an unfolded stable state corresponding to a so-called verticalization position of the structure in which the mass which the latter represents is substantially centered with respect to the support polygon.

2 - lifting device according to claim 1, characterized in that the structure comprises a footrest (22), a seat (20) and a backrest (21) articulated by its base on the rear part of the seat and linked by a deformable quadrilateral (32) to that of the seat with which it comprises a common movable part (25).

3 - A lifting device according to claim 1 or 2, characterized in that the articulated structure is mounted on the chassis by deformable quadrilaterals which are organized in two lateral assemblies (24).

4 - A lifting device according to claim 1 or 2, characterized in that the articulated structure is mounted on the chassis by deformable quadrilaterals which are organized in the form of a column. 5 - Lifting device according to one of claims 1 to 4, characterized in that the structure comprises a seat (20) which is articulated by its front part and substantially by its middle part on the upper ends of the movable parts (25 , 26) constituting the quadrilaterals and respectively called front and rear and linked to the lower part (3) and to the rear part (14) of the chassis.

6 - lifting device according to one of claims 1 to 5, characterized in that the structure comprises a footrest (22) which is articulated by its front part and by its rear part on, respectively, the upper end an anterior movable part (43) constituting the deformable quadrilateral (42), itself articulated on the lower part of the chassis and the so-called front movable part (26) of the deformable quadrilateral (23) specific to the seat.

7 - A lifting device according to one of claims 1 to 6, characterized in that the motor member (50) is constituted by an energy transformer inteφosed between the frame (2) and the quadrilateral (23) specific to the 'seated. 8 - A lifting device according to one of claims 1 to 6, characterized in that the motor member (50) is constituted by a manually controlled means associated with at least one elastic compensator.

9 - Verticalizing wheelchair comprising an articulated structure linked to the chassis by a lifting device according to one of claims 1 to 8.