Telescopic inclinable footrest device for a motorised wheelchair

Abstract

The invention relates to a telescopic inclinable footrest device for a motorised wheelchair, wherein the wheelchair comprises a frame (1) which pivots the structure (3) of a legrest (2) comprising a sliding plate (4), the structure (3) being pivotably mounted so as to pivot between a deployed end position and a stowed end position, the steps of pivoting and sliding the legrest (2) being provided by motor means. The motor means consist of a single cylinder (30) that is rigidly attached to the structure (3) and to the frame (1), wherein a portion of the retraction stroke of the cylinder (30) brings the structure (3) into the stowed position while the extension of the retraction stroke of the cylinder (30) generates the movement of a pulley (11) borne by the rod of the cylinder over which passes a strap (5) which connects the plate (4) to the frame (1), said movement being suitable for shortening the path of the strap (5) and thus deploying the plate (4).

Description

[0001] The present invention relates to the field of motorized wheelchairs, and more particularly to a telescopic footrest device.

[0002] A wheelchair mainly consists of a rolling chassis on which is attached a seat comprising, in addition to a seat, a backrest and armrests, a leg rest including a platform fitted with cushions to rest the calves and which is angle adjustable by being pivotally mounted on the chassis, so that the user can find the most comfortable position possible between the two extreme positions, legs bent and legs extended.

[0003] On the other hand, generally and usually, the leg rest has at its free end a footrest, in the form of a roughly perpendicular paddle, with an adjustable angle.

[0004] Finally, the pads and footrest have adjustment mechanisms allowing the user to find the most comfortable position.

[0005] The possibility of varying the angle of the leg rest relative to the chair poses a problem, namely that the pivot axis of the leg rest and that of the user's knee joint are not coaxial, but very eccentric, the pivot axis of the leg rest being in particular located below and behind that of the knee joint.

[0006] Thus, when transitioning from a bent-legged to a fully extended position, for example, the distance between the footrest and the knee joint decreases, leaving less legroom. To overcome this drawback, the platform is mounted on a sliding, pivoting structure, allowing the distance between the footrest and the knee joint to be adjusted as the angle of inclination changes.

[0007] The sliding stroke of the platform is not limited to this adaptation, it is advantageously planned to be able to extend the deployment of the platform until the footrest pallet comes into contact with the ground, in order to facilitate the transfer of the user.

[0008] Thus the footrest / leg rest has two functions, on the one hand pivoting associated with a compensatory extension, and on the other hand extension until resting on the ground.

[0009] The first feature, which combines two movements, is achieved in a known way through an electric actuator connecting the two pivoting parts, so that tilting in one direction or the other automatically generates the lengthening or shortening of the leg rest.

[0010] The second functionality consists of a purely rectilinear movement which therefore cannot be achieved by the cylinder of the other functionality, so that this movement is generated, in a manner known per se, by a second cylinder, dedicated to this functionality.

[0011] The known footrest devices, which have these two functionalities, are therefore necessarily equipped with two cylinders, namely electric cylinders.

[0012] We know, from the state of the art, of European patent application EP 2 438 896 which describes a wheelchair comprising at least three wheels, a seat, and a backrest, the wheelchair further comprising a leg rest connected to the frame and a footrest.

[0013] The leg rest is connected to the frame so that it can pivot around a pivot axis and can be manually and continuously pivoted between a downward position, in which the footrest is automatically moved towards the pivot axis, and an upward position, in which the footrest is automatically moved in a direction away from the pivot axis.

[0014] It is also known, in the US patent document US2003075967, as a liftable leg rest for a wheelchair.

[0015] The present invention aims to provide a telescopic tilting footrest device for a motorized wheelchair, which has the two aforementioned functionalities, but whose implementation requires only one cylinder.

[0016] The telescopic tilting footrest device for a motorized wheelchair according to the invention, wherein said wheelchair comprises a rolling chassis on which is mounted a chair comprising, in addition to a seat, a backrest and armrests, a leg rest consisting of a platform fitted with cushions for resting the calves and which is of adjustable angle and adaptable length by being slidably mounted on a structure pivotally mounted on said chassis, said platform having at its free end a footrest in the form of an adjustable angle pallet, said structure being pivotally mounted between two extreme positions deployed and folded, while said leg rest is deployable to the ground by the movement of said platform when said structure is in a vertical or substantially vertical position, the pivoting of said structure as well as the sliding of said leg rest being ensured by motorized means,and it is characterized in that said driving means consist of a single cylinder fixed on one side by pivot to said structure and on the other side by pivot to said chassis by means of a pivot eccentric to the axis of pivot of said structure on said chassis such that part of the retraction stroke of said cylinder brings said structure into the folded position, while said pivot is able to move on said chassis, perpendicular to its axis of pivot and under the action of an extension of the retraction stroke of said cylinder, said pivot carrying a pulley over which passes a strap or similar which connects said platform to said chassis by passing over intermediate right-angle pulleys, the movement of said pivot and therefore of said pulley being able to modify the path of said strap or similar and thus to effect the deployment of said platform, or vice versa.

[0017] According to an additional feature of the device according to the invention, it comprises two intermediate return pulleys, one fixed to the pivoting structure near the pivot axis of the latter, the other fixed to the free end of a connecting rod whose other end is pivotally mounted on the chassis, the strap or similar passing successively, from said chassis, over the pulley of said connecting rod and then over the pulley of said structure before being attached to the platform.

[0018] According to another additional feature of the device according to the invention, the pivot of the cylinder pulley is movable in translation in a guide path of the chassis, of substantially vertical orientation, the end of which closest to the pivot axis of the structure corresponds to the position allowing the pivoting of the latter.

[0019] According to another additional feature of the device according to the invention, it includes means for immobilizing the pivot of the cylinder pulley in the guide path at its end closest to the pivot axis of the structure, during the deployment and folding operations of the latter.

[0020] According to another additional feature of the device according to the invention, the means suitable for immobilizing the pivot consist of at least one controlled compression means.

[0021] According to another additional feature of the device according to the invention, the controlled compression means consists of a gas spring.

[0022] The advantages and characteristics of the footrest device according to the invention will become clearer from the following description, which relates to the attached drawing, which represents a non-limiting embodiment thereof.

[0023] In the attached drawing: there figure 1 represents a schematic profile view of a footrest device according to the invention in its horizontally deployed position, the figure 2 represents a schematic profile view of the same footrest device during folding, the figure 3 represents a schematic profile view of the same footrest device in the folded position, the figure 4 represents a schematic profile view of the same footrest device in the deployed position down to the ground.

[0024] In these figures we can see part 1 of the chassis of a motorized wheelchair, not shown, as well as a footrest device 2 according to the invention, carried by a structure 3 mounted pivotally on part 1 around a shaft 10, with a horizontal axis and transverse to the direction of movement of the wheelchair.

[0025] The footrest device 2 includes a platform 4 mounted sliding on the structure 3 through a slide 34, and which has on the upper part pads 40, only one of which is visible, intended to rest the legs, and more particularly the calves, and on the other hand at its free end, a footrest paddle 41.

[0026] As can be seen on the figures 1, 2 And 3 Structure 3 is mounted to pivot, allowing it to move from a roughly horizontal deployed position, as shown on the... figure 1 , in a folded, roughly vertical position, as shown on the figure 3 .

[0027] The pivoting of the structure 3 is ensured by a jack 30, preferably electric, fixed in pivot to the structure 3, and whose rod 31 is made fixed to the part 1 of the chassis.

[0028] The end of the rod 31 carries a pulley 11 via a pivot 12 fixed to part 1 of the frame. The pivot 12, whose axis is parallel to that of the shaft 10, is mounted to move in translation within a guide groove 13 in part 1, which extends substantially vertically. In fact, part 1 has two parallel grooves 13, only one of which is visible, in each of which an extreme portion 15 of the pivot 12 can move.

[0029] It can also be seen that part 1 of the chassis includes a gas spring 14, which pushes back and locks the pivot 12 in the upper end 16 of the groove 13, which is eccentric with respect to the axis of the shaft 10.

[0030] It will be understood that when the cylinder 3 is fully extended, the structure 3 is in a deployed position approximately horizontal, and that when the rod 31 is retracted, the structure 3 folds back.

[0031] To compensate for the fact that the pivot axis of structure 3 and that of the user's knee joint are not coaxial, the leg rest should lengthen during deployment, and conversely during folding, which is achieved by sliding the platform 4 on structure 3.

[0032] This sliding in one direction or another is obtained by shortening or lengthening a strap or similar 5, one end 50 of which is fixed to the movable plate 4, while the other end 51 is fixed to part 1 of the chassis.

[0033] It should be noted that, but not limited to, a strap is preferentially used.

[0034] This shortening or lengthening is obtained by pivoting the structure 3, through the movement of a return pulley 32, which is mounted at the free end of a connecting rod 17, articulated on the part 1 of the chassis, and which extends under the structure 3. On the other hand, the structure 3 includes, near the shaft 10, a return pulley 33.

[0035] Thus, the strap 5 passes successively, from the fixing of its end 50 on the movable plate 4, over the return pulley 33, over the return pulley 32 by passing under the pivoting structure 3, then over the pulley 11 before being fixed to the part 1 of the chassis by its end 51.

[0036] During the pivoting and folding of the structure 3, the connecting rod 17 is forced to fold and its return pulley 32 moves away from the return pulley 33, which lengthens the distance between the ends 50 and 51 of the strap 5 and thus causes the plate 4 to slide towards the shaft 10. Conversely, during the deployment of the structure 3, the return pulley 32 moves closer to the return pulley 33, which shortens the distance between the ends 50 and 51 of the strap 5 and allows the plate 4 to move away from the shaft 10.

[0037] This configuration allows the platform 4 to move according to the pivoting of the structure 3.

[0038] On the figure 3 Structure 3 is in its fully folded position, cylinder 30 is in the plane of the groove, and its rod 31 is not fully retracted. Therefore, further retraction of rod 31 causes pivot 12 to slide in groove 13, compressing gas spring 14. This results in the displacement of pulley 11, and consequently, the shortening of the distance between the ends 50 and 51 of strap 5, without movement of connecting rod 17. This, in turn, allows the platform 4 to slide on structure 3 until the footrest pallet 41 is deployed on the ground by gravity, as shown in the diagram. figure 4 .

[0039] The use of a gas spring 14 is an economical solution, however other solutions can be considered, a compression spring for example, the main thing being to allow the pivot 12 to be immobilized at the upper end 16 of the groove 13, during pivoting movements of the structure 3.

[0040] Thus, the two functionalities of the footrest device according to the invention, namely its pivoting with adaptability of length, and deployment to the ground, are ensured by means of a single cylinder.

Claims

1. A telescopic inclinable footrest device for a motorized wheelchair, wherein said wheelchair comprises a rolling frame (1) on which is secured a chair comprising, in addition to a seat, a backrest and armrests, said device comprises a legrest (2) consisting of a plate (4) furnished with pads (40) for resting the calves and whose angle is adjustable and whose length is adaptable by being slidably mounted on a structure (3) pivotably mounted on said frame (1), said plate (4) comprising at its free end a footrest (41) in the form of a paddle whose angle is adjustable, said structure (3) being pivotably mounted between two extreme positions, deployed and stowed, while said legrest (2) is deployable to the ground by movement of said plate (4) when said structure (3) is in a vertical or substantially vertical position, the pivoting of said structure (3) and the sliding of said legrest (2) being provided by motor means, and is characterized in that said motor means consist of a single cylinder (30) pivotably connected on one side to said structure (3) and on the other side to said frame (1) via a pivot (12) eccentric to the pivot axis (10) of said structure (3) on said frame (1), so that a portion of the retraction stroke of said cylinder (30) brings said structure (3) into a stowed position, while said pivot is able to move on said frame (1), perpendicularly to its pivoting axis and under the action of an extension of the retraction stroke of said cylinder (30), said pivot (12) bearing a pulley (11) over which passes a strap or the like (5) which connects said plate (4) to said frame (1) by passing over intermediate angle-reversing pulleys (32, 33), the movement of said pivot (12) and thus of said pulley (11) being capable of modifying the path of said strap or the like (5) and thus deploying said plate (4), or vice versa.

2. The footrest device according to claim 1, characterized in that it comprises two intermediate return pulleys (32, 33), one (33) rigidly attached to the pivoting structure (3) close to the pivot axis (10) thereof, the other (32) rigidly attached to the free end of a connecting rod (17), the other end of which is pivotably mounted on the frame (1), the strap or the like (5) passing successively, from said frame (1), over the pulley (32) of said connecting rod (17) and then over the pulley (33) of said structure (3) before being attached to the plate (4).

3. The footrest device according to claim 1 or claim 2, characterized in that the pivot (12) of the pulley (11) of the cylinder (30) is translationally movable in a substantially vertically oriented guideway (13) of the frame (1), whose end (16) closest to the pivot axis (10) of the structure (3) corresponds to the position allowing the pivoting thereof.

4. The footrest device according to claim 3, characterized in that it comprises means (14) for immobilizing the pivot (12) of the pulley (11) of the cylinder (30) in the guideway (13) at its end (16) closest to the pivot axis (10) of the structure (3), during the deployment and stowing operations thereof.

5. The footrest device according to claim 4, characterized in that the means for immobilizing the pivot (12) consist of at least one controlled-compression means (14).

6. The footrest device according to claim 5, characterized in that the controlled-compression means consists of a gas-operated cylinder (14).

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