Wheelchair having wheel-support struts hinged on a seat-support plate so that the struts can be grouped together in the folded position

Abstract

The invention relates to a wheelchair, of the type comprising a frame (1) from which at least three struts (2) extend, each having a lower end (20) bearing at least one wheel (R) and an upper end (21) connected to the frame, these struts including two lateral struts (2L) each bearing a lateral wheel (22) and at least one central strut (2C) bearing at least one directional wheel (23), the lateral struts, when in a rolling configuration, having an inclined position in which the lower ends thereof are set further apart than the upper ends thereof, the wheelchair being characterized in that the frame (1) comprises a central plate (10), at least the lateral struts (2L) each being hinged on a pivot (100) on the central plate (10) and being able to move about the pivot between the rolling configuration and a folded configuration in which the lateral struts (2L) are pivoted towards the central strut (2C) and grouped close together.

Description

[0001] The field of the invention is that of the design and manufacture of equipment for people with reduced mobility.

[0002] More specifically, the invention relates to a wheelchair of the type comprising at least three wheel-supporting legs, including two side wheels and a central, front or rear wheel.

[0003] The range of wheelchairs is now very wide to meet different conditions of use and also aesthetic choices, corresponding for example to the personality of the user, with possibilities of general appearance either traditional or modern.

[0004] We can distinguish two main families of wheelchairs, namely: so-called transfer or transport chairs; chairs designed for sports activities.

[0005] In the category of transfer or transport wheelchairs, these have a very classic general structure, comprising a supporting frame with two rear wheels and two directional front wheels (the rear wheels traditionally being of a diameter significantly greater than that of the front wheels), the frame carrying a seat and a backrest.

[0006] Of course, many accessories can be offered to provide different functionalities and / or improve user comfort.

[0007] As mentioned previously, many variations of these armchairs are available, including, for example: "shell" wheelchairs; specific bathroom and toilet chairs; wheelchairs for obese people; wheelchairs for small people; electric wheelchairs; wheelchairs with reclining backrests; standing wheelchairs;

[0008] Some of these wheelchairs are foldable, whether in combination with one of the chairs listed above or not.

[0009] According to a very widespread design of these folding wheelchairs, these comprise two lateral sub-assemblies, each carrying a rear wheel and a front wheel, the two sub-assemblies being connected by two rigid elements crossing and being articulated together at their center, so that the two sub-assemblies can be moved apart from each other in the rolling position or, in the folding position, brought together, almost against each other.

[0010] Wheelchairs of this type are described in particular in the patent documents published under the numbers EP2328536, EP2985014, EP2796121, EP2140846 or EP3120819.

[0011] Such a design, while it undoubtedly ensures the wheelchair's folding function, requires the use of numerous parts, which tends to: complicate the design, with numerous points of articulation; complicate the assembly of the chair; considerably increase the weight of the chair; increase the cost price and, consequently, the selling price of the chair.

[0012] EP2075183 discloses a folding wheelchair, comprising a frame from which three legs extend.

[0013] Another type of design is described by the patent document published under the number EP3156027. According to this design, the chair is folded by tilting the backrest forward, which simultaneously causes the legs carrying the front wheels to tilt backwards (these two front legs being mounted articulated on the seat support). Thus, in the folded position, the chair has a configuration according to which the backrest is folded against the seat support and the front wheels are brought closer to the rear wheels, extending in front of them.

[0014] Such a design not only does not overcome the disadvantages mentioned above but also causes a relatively large footprint in the folded configuration of the chair.

[0015] In the category of wheelchairs for sports activities, these are of a specific design, particularly for speed sports, with a very elongated general shape, due to the presence of a single, very offset front wheel. The frames of these chairs are traditionally fixed, not cushioned, in order to offer optimal rigidity to provide stability.

[0016] Furthermore, to ensure their maneuverability, sports wheelchairs are designed to be as light as possible. For this reason, sports wheelchairs do not incorporate complex folding structures, such as those mentioned above.

[0017] The invention aims in particular to overcome these drawbacks of the prior art.

[0018] More specifically, the invention aims to provide a wheelchair, of the transfer or transport type or of the type for sports activity, which has a structure that is both light for its maneuverability and which is designed to allow the chair to be folded.

[0019] The invention also aims to provide such a wheelchair which allows one to move from a rolling configuration to a folded configuration, or vice versa, easily and quickly.

[0020] The invention also aims to provide such a wheelchair which, although of light structure, ensures the comfort of the user.

[0021] These objectives, as well as others which will appear subsequently, are achieved thanks to the invention which relates to a wheelchair, of the type comprising a chassis from which extend at least three legs each having a lower end carrying at least one wheel and an upper end connected to the chassis, among which two lateral legs each carrying a lateral wheel and at least one central leg carrying at least one directional wheel, the legs having, according to a rolling configuration, an inclined position in which their lower ends have a spacing between them greater than that between their upper ends, in which the chassis comprises a central plate, at least the lateral legs each being mounted articulated around a joint on the central plate and movable around the joint between the rolling configuration and a folding configuration, in which the lateral legs are pivoted, in the direction of the central leg, and grouped in the vicinity of each other, characterized in that the chassis comprises, for each leg, a pivoting stop surmounting the leg to prevent the pivoting of the leg beyond a predetermined angular travel from the rolling configuration, and in that the plate has, for each leg, a cage in which extends an axis around which the leg is capable of pivoting, the upper end of the leg being housed in the cage, and a part, constituting the pivoting stop, is attached to the plate to close the cage from above.

[0022] Thus, thanks to the invention, a wheelchair can have two characteristics which are a priori antagonistic according to the prior art, namely: having a light chassis and being foldable.

[0023] Indeed, according to the invention, folding is not obtained by means of a complex chassis using articulated crosses, connecting rods or even locking systems, and does not involve the use of lateral tubular sub-assemblies and / or seat support.

[0024] Conversely, the chassis of a wheelchair according to the invention is foldable thanks to the implementation of a particularly light structure in which the chassis is essentially reduced to the plate, and in which folding is simply obtained by mounting the legs in an articulated manner on the plate. It is understood that with such a technique, folding or unfolding is carried out quickly and simply, since it is sufficient to pivot the lateral legs, and possibly the central leg, to move them from the rolling position to the folded position, or vice versa.

[0025] Furthermore, as will become more clear later, the person handling the wheelchair to bring it into its rolling configuration has very few actions to take, and does not have to worry about locking it in the rolling configuration since the simple weight of the person sitting on the wheelchair ensures that the wheelchair is kept in its rolling configuration.

[0026] It is also noted that such a wheelchair, in addition to its particularly low weight, has a small footprint. Indeed, as indicated previously, the chassis being essentially made up of the plate which supports the legs, this can be designed with reduced dimensions, that is to say dimensions necessary and sufficient to constitute a seat support between the two side wheels.

[0027] In any event, it is clear from the design of a wheelchair according to the invention that the chassis thereof, and the articulated leg system, together involve a limited number of parts. As a result, such a wheelchair involves reduced manufacturing costs, as well as relatively low assembly costs and assembly times compared to those incurred with the techniques of the prior art.

[0028] As mentioned previously, to move the wheelchair from its folding configuration to its rolling configuration, the user simply pivots the legs until they come into contact with the chassis. Since the legs occupy an inclined position in the rolling position (in which the longitudinal axis of the legs forms a non-zero angle with the vertical axis and the distance between the lower ends of the lateral legs is greater than or equal to the width of the plate), the simple weight of a person sitting on the chair (or even the simple weight of the chair itself) is sufficient to maintain both: the inclined position of the legs, i.e. the rolling configuration; the locking in a predetermined maximum angular position relative to the vertical of the legs, these, by their upper end, being locked in pivoting, which tends to “self-lock” the rolling configuration.

[0029] According to a first conceivable embodiment, in the folding configuration, the legs are pivoted and grouped close to each other under the plate.

[0030] In this case, the side legs are advantageously mounted articulated on the plate around an axis parallel to a median axis between the side legs.

[0031] According to a second possible embodiment, the lateral legs are mounted articulated on the plate around an axis orthogonal to a median axis between the lateral legs.

[0032] In this second case, we obtain a grouping of the legs around the central leg (which occupies a position in front or behind the plate depending on the case), the central leg remaining substantially in the same folding configuration or in the rolling configuration.

[0033] According to a preferred solution, the central leg is also mounted articulated on the plate, around an axis orthogonal to a median axis between the lateral legs.

[0034] This way, the user has more freedom in terms of the folded configuration he can adopt.

[0035] According to an advantageous embodiment, the wheelchair comprises, for each leg, at least one shock absorber between the leg and the plate, in contact with the leg and the plate in the rolling configuration, and intended to produce a damping of the inclination of the leg for a pivoting of the leg when approaching a predetermined angular travel from the folding configuration.

[0036] Such an embodiment obviously tends to significantly improve user comfort. The presence of shock absorbers, under the seat, between the chassis and the legs, makes it possible to absorb any jolts or shocks received by the wheels and avoids transmitting them, or at the very least attenuates them, so that the person using the wheelchair does not feel them or feels them only slightly. This is all the more important since these people are required to spend many hours in the wheelchair.

[0037] In this case, the plate has, for each leg, a cage in which extends an axis around which the leg is capable of pivoting, the upper end of the leg being housed in the cage facing a bottom of the cage, the shock absorber being mounted in the extension of the upper end of the leg and intended to come to bear against the bottom of the cage.

[0038] This method of implementation proves to be particularly effective and also has the advantage of requiring very simple and rapid assembly.

[0039] Advantageously, the shock absorber is made up of an elastomer pad.

[0040] Again, the installation of such a cushion is quick and easy. In addition, such a shock absorber can be easily replaced with another, for example to change the damping stiffness.

[0041] According to a particular solution, the plate comprises two blocks, one on top of the other, providing between them the housings for the articulation axes of the legs. Such a solution makes it easier to mount the articulation axes of the legs, with machining of the blocks in question being able to be carried out inexpensively.

[0042] According to another advantageous solution, the plate has, for each leg, a groove in height in which the upper end of the leg is housed and allows pivoting movement of the leg.

[0043] Such a mounting therefore allows the upper end of the legs to be embedded in the plate while allowing the legs to pivot around their articulation on the plate. Thus, the articulated mounting of the legs on the plate is achieved without having to increase the dimensions of the plate to allow the mounting and pivoting of the legs.

[0044] Other characteristics and advantages of the invention will appear more clearly on reading the following description of a preferred embodiment of the invention, given as a simple illustrative and non-limiting example, and the appended drawings among which: THE Figures 1 and 2are overall views of a wheelchair according to the invention, respectively in rolling configuration and in folded configuration; Figures 3 and 4 are perspective views of a subassembly of a wheelchair according to the invention, respectively in rolling configuration and in folded configuration; Figures 5 and 6 are top views of a subassembly of a wheelchair according to the invention, respectively in rolling configuration and in folded configuration; the figure 7 is a view of a subassembly of a wheelchair according to an alternative embodiment of the invention, in which the transition from the rolling configuration to the folded configuration is schematically illustrated; figures 8 and 9 schematically illustrate the chassis of a wheelchair according to the invention, respectively seen in perspective and from the side.

[0045] In reference to the figures 1 to 6 , a wheelchair according to the invention is of the type comprising: a chassis 1; at least three legs 2, extending from the chassis 1 and each having a lower end 20 carrying at least one wheel R, each leg having an upper end 21 connected to the chassis.

[0046] As illustrated by the figures 1 to 6 , the wheelchair according to the invention has: two lateral legs 2L, these lateral legs each carrying a lateral wheel 22; at least one central leg 2C, carrying at least one directional wheel 23 (in this case carrying a hanger 230 provided with a directional wheel at each of its ends).

[0047] The legs 2, and in particular at least the lateral legs 2L, are mounted on the chassis so as to be able to occupy two distinct configurations, namely: a rolling configuration in which the legs occupy an inclined position in which their lower ends 20 have a spacing between them greater than that between their upper ends 21 ( figures 1 And 3 ) ; a folding configuration described in more detail later, and as illustrated by the figures 2 And 4 .

[0048] According to the principle of the invention, the chassis comprises a central plate 10 on which the lateral legs 2L are each mounted articulated around an articulation 100. Thus, the lateral legs 2L are mounted movably on the central plate around the articulation 100 between the rolling configuration ( figures 1 And 3 ) and the folding configuration ( figures 2 And 4 ).

[0049] As it appears on the figures 2 , 4 And 7, the side legs 2L are pivoted into the folding configuration toward the central leg 2C, the legs 2 being grouped in the vicinity of each other in the folding configuration.

[0050] According to the embodiment illustrated by the Figures 5 and 6 , the legs 2 are, in the folding configuration, pivoted and grouped in the vicinity of each other under the plate 10.

[0051] It is noted that, according to this embodiment, the central leg 2C is also mounted articulated on the plate 10.

[0052] To move from the rolling configuration to the folding configuration as specified above, the lateral legs 2L are mounted articulated on the plate 100 around an axis 101 parallel to a median axis A ( Figure 5 ) between the lateral legs 2L. The central leg 2C is mounted articulated on the plate 10 around an axis 103 orthogonal to the median axis A between the lateral legs 2L.

[0053] To proceed with the folding of the wheelchair according to the invention, it is therefore understood that the legs 2 are pivoted from the rolling configuration around their respective articulation. Thus, the lateral legs 2L are pivoted towards the space extending under the plate 10, as well as the central leg 2C. Ultimately, the lateral legs 2L are indeed pivoted towards the central leg 2C when the latter occupies its position in the folding configuration. In addition, the legs 2 are all grouped together in the vicinity of each other under the plate 10.

[0054] According to the embodiment variant illustrated by the figure 7 , the lateral legs 2L are mounted articulated on the plate 10 around an axis 102 orthogonal to the median axis A between the lateral legs 2L.

[0055] Thus, in this case, when changing from the rolling configuration to the folding configuration, the lateral legs 2L are, from the rolling configuration, pivoted around each of their axis 102 in the direction of the central leg 2C, as illustrated by the arrows F1 and F2 (the central leg being able to remain in the same position in the rolling configuration and in the folding configuration). Finally, in the folding configuration, the legs are grouped together in the vicinity of each other, in front or behind the chair depending on the position of the central leg 2C.

[0056] In reference to the figures 3, 4 , 7 and 8 , the mounting of the legs on the plate is carried out as described below.

[0057] For each leg, the plate 10 has a cage 12 in which extends the axis around which the corresponding leg 2 is capable of pivoting. Thus, for the lateral legs 2L, the axis 101 extends in the cage 12 and, for the central leg 2C, the axis 103 extends in the cage 12. In addition, the upper end 21 of the legs 2 is housed in the cage 12.

[0058] It is noted that this cage 12 is delimited by the walls of a groove 105 extending over the entire height of the plate 10 allowing both the upper end 21 of each leg to be housed and allowing pivoting movement of the leg inside the groove.

[0059] Furthermore, the chassis comprises, for each leg, a pivoting stop 11 surmounting the leg to prevent the leg from pivoting beyond a predetermined angular travel from the rolling configuration, i.e. so that the legs do not have, with respect to the vertical, an inclination greater than that illustrated by the figures 1 And 3 For example.

[0060] To do this, according to the present embodiment, a part constituting the pivoting stop 11 is attached to the plate 10 to close the cage 12 from above.

[0061] This part 110, as illustrated by the figures 8 and 9 , also constitutes a seat support coupled to the plate 10, with, for information purposes, a series of elastic balls 111 interposed between the part 110 and the plate 10.

[0062] Furthermore, for each leg 2, a shock absorber 24 is interposed between the corresponding leg 2 and the plate 10. These shock absorbers are intended to be in contact with the leg and the plate in the rolling configuration, to produce damping of the inclination of the leg for pivoting of the leg when approaching a predetermined angular travel from the folding configuration.

[0063] In other words, in the rolling configuration as illustrated by the figures 1 And 3 for example, each shock absorber is in contact with a leg and the plate, such that, due to shocks or vibrations exerted on the wheels of the chair or due to jolts imposed by the user himself, each shock absorber is likely to be compressed to absorb the corresponding jolt or vibration.

[0064] According to the present embodiment, each shock absorber is mounted in the extension of the upper end of a leg and is intended to come into contact with the bottom 120 of the corresponding cage 12 in the rolling position of the chair.

[0065] According to the design which has just been described, the angular travel of each leg, from the folding position, is limited by the upper surface 210 of the upper end 21 of each leg coming into abutment against the lower face of the part 110 which closes each cage 12 in height. Before coming into abutment against this part 110, the shock absorbers 24 are compressed between the upper end 21 of each leg, or of one of the legs, thus preventing the upper surface from impacting the part 110 in a manner which is too perceptible to the user of the chair.

[0066] It is noted that with such an assembly, the weight of the user installed in the chair tends to constrain the legs in the rolling configuration. Indeed, the weight of the user is exerted on the seat support constituted by the part 110, which results in a force from the lower face of the part 110 being exerted on the upper ends 21 of the legs. However, as illustrated by the figure 3, as long as the legs have not reached the predetermined maximum angular travel from the rolling configuration, the upper ends protrude upwards above the corresponding cage 12, this protruding part extending between the axis of the articulation and the bottom of the cage. As a result, by pressing on this protruding part of the upper end above the cage, pressing on it tends to promote the inclined position of the rolling configuration. On the other hand, once the predetermined maximum angular travel has been reached, the upper surface of the upper ends of the legs is in abutment under the part 110, preventing each leg from tilting further.

[0067] According to a preferred embodiment, each shock absorber 24 is constituted by an elastomer pad. These elastomer pads each have a base and the upper ends of the legs have a cavity intended to receive the base of the pads. The mounting of the base of the pads in the cavity is carried out in a slightly forced manner (i.e. by compressing the elastomer material of the pad to introduce it into the cavity of the upper end), ensuring that the pad is held in the upper end of the corresponding leg.

[0068] According to another characteristic of the present embodiment, the plate 10 comprises two blocks 102 and 103 arranged one on top of the other ( figures 8 and 9 ) and providing accommodation between them 104 ( figure 8) intended to receive the articulation axes of the legs. The two blocks 102 and 103 are secured together by means of fixing means passing through the two blocks, the elastic balls 111 and the part 110.

Claims

1. A wheelchair, of the type comprising a frame (1) from which at least three struts (2) extend each having a lower end (20) carrying at least one wheel (R) and an upper end (21) connected to the frame, including two lateral struts (2L) each carrying a lateral wheel (22) and at least one central strut (2C) carrying at least one steered wheel (23), the lateral struts having, according to a rolling configuration, an inclined position in which their lower ends have a spacing therebetween larger than that one between their upper ends, wherein the frame (1) comprises a central plate (10), at least the lateral struts (2L) each being hingedly mounted around a joint (100) on the central plate (10) and movable around the joint between the rolling configuration and a folding configuration, in which the lateral struts (2L) are pivoted, in the direction of the central strut (2C), and grouped together adjacent to each other, characterised in that the frame (1) comprises, for each strut (2), a pivoting stop (11) on top of the strut (2) to prevent pivoting of the strut beyond a predetermined angular stroke from the rolling configuration, and in that the plate (10) has, for each strut (2), a cage (12) in which an axis (101) extends around which the strut (2) could pivot, the upper end (21) of the strut being accommodated in the cage (12), and in that a part (110), making up the pivoting stop (11), is affixed on the plate (10) so as to close the cage (12) from above.

2. The wheelchair according to claim 1, characterised in that, in the folding configuration, the struts (2) are pivoted and grouped together in the vicinity of each other under the plate (10).

3. The wheelchair according to claim 2, characterised in that the lateral struts (2L) are hingedly mounted on the plate (10) about an axis (101) parallel to a median axis (A) between the lateral struts (2L).

4. The wheelchair according to claim 1, characterised in that the lateral struts (2L) are hingedly mounted on the plate (10) about an axis (102) orthogonal to a median axis (A) between the lateral struts (2L).

5. The wheelchair according to any one of claims 1 to 4, characterised in that the central strut (2C) is also hingedly mounted on the plate (10), about an axis (103) orthogonal to a median axis (A) between the lateral struts (2L) .

6. The wheelchair according to any one of claims 1 to 5, characterised in that it comprises, for each strut (2), at least one damper (24) between the strut (2) and the plate (10), in contact with the strut (2) and the plate (10) in the rolling configuration and intended to produce a damping of the inclination of the strut for a pivoting of the strut approaching a predetermined angular stroke from the folding configuration.

7. The wheelchair according to claim 6, characterised in that the upper end (21) of the strut is accommodated in the cage (12) facing a bottom (120) of the cage, the damper (24) being mounted in the extension of the upper end (21) of the strut and intended to bear against the bottom (120) of the cage.

8. The wheelchair according to claim 7, characterised in that the damper (24) consists of an elastomeric cushion.

9. The wheelchair according to any one of claims 1 to 8, characterised in that the plate (10) comprises two blocks (102), (103) on each other forming therebetween compartments (104) for hinge axes of the struts.

10. The wheelchair according to any one of claims 1 to 9, characterised in that the plate (10) has, for each strut (10), a heightwise groove (105) in which the upper end (21) of the strut is accommodated and enabling a pivotal travel of the strut (2).

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