Tiltable leg rest device for wheelchair

Description

[0001] The present invention relates to the field of wheelchairs, and more particularly to an adjustable leg rest device.

[0002] A wheelchair mainly consists of a rolling chassis on which is attached a chair comprising, in addition to a seat, a backrest and armrests, a leg rest, consisting of 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 a footrest at its free end, in the form of a platform or adjustable angle pallet.

[0004] Finally, the pads and footrest preferably include means of adjustment, allowing the user to find the most comfortable position.

[0005] The possibility of varying the angle of the leg rest relative to the chair, however, 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 located below and behind that of the knee joint.

[0006] Thus, when moving from the position with legs bent to the position with legs extended, for example, the distance between the footrest and the axis of the knee joint decreases, therefore leaving less room for the legs, and vice versa when folding.

[0007] To overcome this drawback, the leg rest device includes a pivoting structure mounted on the chair frame on which the cushioned platform can slide longitudinally, perpendicular to the pivot axis, so as to allow adaptation and adjustment of the distance between the footrest and the axis of the knees.

[0008] However, another problem remains: when moving from a bent-legged to a straight-legged position, the feet are supported on the footrest, but the pivot axis of the structure that supports the leg rest is placed below the axis of the knees, so that the user's calves no longer touch the pads, which presents discomfort for the user, since the legs end up in hyperextension.

[0009] Of course, during the reverse movement from the position of extended legs to bent legs, the symmetrical problem arises, namely that if the calves rest on the pads, the feet are no longer against the footrest.

[0010] To overcome this drawback, various devices have been proposed to adjust the height of the bearings, often manually, sometimes automatically via a set of connecting rods, for example. However, these devices have disadvantages, notably that to achieve the desired bearing height adjustments, they alter the initial position, which is actually the most comfortable for the user.

[0011] US patent application US2003075967 describes a flip-up leg rest for a wheelchair. The leg rest comprises a frame to support the lower leg of a user, the frame being attachable to the wheelchair, and being movable between a lowered and raised position around a pivot point when attached to the wheelchair.

[0012] However, this document does not resolve the aforementioned drawbacks.

[0013] The present invention aims to remedy the various aforementioned drawbacks by proposing a leg rest device of simple design, which allows switching from a bent-legged to a stretched-legged position and vice versa, without changing the initial position chosen to be the most comfortable for the user.

[0014] The tilting leg rest device for a wheelchair according to the invention, wherein said wheelchair comprises a rolling chassis on which is fixed a chair comprising, in addition to a seat, a backrest and armrests, said leg rest comprising a structure mounted pivoting on said chassis, so that the user can find a position between two extreme positions, legs bent and legs extended, said leg rest also comprising a platform or the like fitted with cushions for resting the calves, and which is mounted sliding on said pivoting structure, so as to allow adjustment in length and adaptation of the positioning of said cushions, and it is characterized in that said platform is mounted sliding on said pivoting structure through a curved guide path, which is convex on the side supporting the legs.

[0015] Thus, the curvature of the path traveled by the platform during its translation generates an elevation of said platform relative to the general plane of the pivoting structure, sufficient to compensate for the offset due to pivoting.

[0016] According to an additional feature of the tilting leg rest device according to the invention, the pivoting structure is driven by an electric actuator, attached to said pivoting structure, and whose rod is attached to the chassis, through a pivot with an axis eccentric relative to that of pivoting of said pivoting structure.

[0017] According to another additional feature of the tilting leg rest device according to the invention, the movable platform is connected to the frame by means of a strap or similar device, which passes over return pulleys, one of which is movable under the effect of pivoting, so as to generate a modification of the path of said strap or similar device during the folding operation, and vice versa, and therefore the displacement of said movable platform.

[0018] According to another additional feature of the tilting leg rest device according to the invention, the pivoting structure includes a first return pulley near the pivot axis of said pivoting structure, while a connecting rod mounted pivotally at one end on the chassis and extending under said pivoting structure has at its other end a return pulley, capable of moving away from said first return pulley during the folding operation, and vice versa.

[0019] The advantages and characteristics of the tilting leg rest 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.

[0020] In the attached drawing: there figure 1 represents a schematic profile elevation view of a leg rest device according to the invention in its folded position, the figure 2 represents a schematic profile elevation view of the same leg rest device in an intermediate deployment position, the figure 3 represents a schematic profile elevation view of the same leg rest device in the deployed position.

[0021] With reference to these figures, a leg rest device according to the invention can be seen, which comprises a structure 1 pivotally mounted on a part 2 of a wheelchair frame not shown, around a pivot 20 and under the action of a jack 3, while a platform 4 is slidably mounted on the structure 1. This platform 4 is equipped with pads 40, only one of which is visible, intended to support the user's calves, and has at its free end a footrest plate 41.

[0022] The pivoting of structure 1 is ensured by the cylinder 3, which is preferably electric, fixed in pivot to structure 2, and whose rod 30 is made fixed to part 2 of the chassis.

[0023] The end of the rod 30 carries a pulley 31 via a pivot 32 fixed to part 2 of the frame, and whose axis is parallel to that of the pivot 20, and eccentric with respect to the latter. It will be understood that the extension stroke of the rod 30 causes the unfolding of the structure 1, as shown in the diagrams. figures 2 And 3 .

[0024] As explained, it is necessary to lengthen the leg rest section during deployment, the distance between the footrest and the axis of the knee joint decreases, which is achieved by sliding the platform 4 on the pivoting structure 1. However, this translation movement should be motorized.

[0025] The sliding in one direction or another is obtained by modifying the path traveled by a strap or similar 5, shown in transparency on these figures, by lengthening or shortening the distance separating its two ends, one of which 50 is fixed to the movable plate 4, while the other 51 is fixed to part 2 of the chassis.

[0026] It should be noted that, but not limited to, a strap is preferentially used.

[0027] This shortening or lengthening is obtained by pivoting the structure 1, under the action of the cylinder 3, through the movement of a return pulley 33, which is mounted at the free end of a connecting rod 21, articulated on the part 2 of the chassis, and which extends under the structure 1. On the other hand, the structure 1 includes, near the pivot 20, a return pulley 34.

[0028] Thus, the strap 5 passes successively, from the fixing of its end 50 on the movable plate 4, over the return pulley 34, over the return pulley 33 by passing under the pivoting structure 1, then over the pulley 31 before being fixed to the part 2 of the chassis by its end 51.

[0029] During the folding pivot of structure 1, the connecting rod 21 is forced to fold and its return pulley 33 moves away from the return pulley 34, which lengthens the path of the strap 5 and thus causes the platform 4 to slide towards the pivot 20. Conversely, during the deployment of structure 3, the return pulley 33 moves closer to the return pulley 34, which shortens the path of the strap 5 and allows the platform 4 to move away from the pivot 20.

[0030] This configuration allows the platform 4 to move according to the pivoting of the structure 1 under the action of the cylinder 3.

[0031] Although this architecture allows for the automatic translation movement of the platform 4 during folding or unfolding, it does not allow for compensation of the variation in height of the legs relative to the pads 40.

[0032] However, according to the invention, the sliding of the plate 4 on the structure 1 is achieved through a curved guide path 10, convex upwards, i.e. in the direction of the plate 4.

[0033] Thus, when raising the leg rest device, that is, when raising structure 1 as shown in the figures 2 And 3 In addition to the lengthening of the leg rest, without modifications to the adjustment between the footrest 41 and the pads 40, the latter, following the curvature of the guide path 10, move away from the general plane of the structure 1 and vice versa when folding.

[0034] According to the invention, the height adjustment of the bearings 40 is carried out automatically during pivoting.

Claims

1. An inclinable leg rest device for a wheelchair, wherein said wheelchair comprises a wheeled frame (2) to which a seat is attached, which seat further comprises a seat portion, a backrest and armrests, said leg rest comprising a structure (1) mounted pivotably on said frame (2) in order for the user to be able to assume a position between two extreme positions of the legs being bent and the legs being straightened, said leg rest additionally comprising a board (4) or the like provided with pads (41) for calf placement, which board is slidably mounted on said pivoting structure (1) so as to enable a lengthwise adjustment and an adaptation of the positioning of said pads (41), characterized in that said board (4) is slidably mounted on said pivoting structure (1) through a curved guide path (10), which is convex on the side that supports the legs.

2. The inclinable leg rest device according to claim 1, characterized in that the pivoting structure (1) is moved by an electric jack (3), secured to said pivoting structure (1), and whose rod (30) is secured to the frame (2), through a pivot with an axis eccentric with respect to the pivot axis (20) of said pivoting structure (2).

3. The inclinable leg rest device according to claim 1 or claim 2, characterized in that the movable board (4) is connected to the frame (2) by means of a strap (5) or the like, which passes over return pulleys (31, 33, 34), one of which (33) is movable under the effect of the pivoting, so as to generate a lengthening of the path of said strap (5) or the like during the folding operation, and vice versa, and thus the displacement of said movable board (4).

4. The inclinable leg rest device according to claim 3, characterized in that the pivoting structure (1) comprises a first return pulley (34) proximate to the pivot axis (20) of said pivoting structure (2), while a connecting rod (21) pivotably mounted by one end on the frame (2) and extending under said pivoting structure (1) comprises, at its other end, a return pulley (33) capable of moving away from said first return pulley (34) during the folding operation, and vice versa.