STANDING CHAIR

Abstract

A standing wheelchair (10) for a user (20), preferably with a disability, is presented. The wheelchair comprises a seat (12), a backrest (14), and a footrest (16). A mechanism for moving the seat (15) is adapted to move the wheelchair from a seated position to a sit-stand position and vice versa. In the seated position, an angle αct between the spine (25) in a straight position and a line Lp joining the user's hip joint (27) to their knee joint (23) is between 85 and 100 degrees. In the sit-stand position, the angle αct is between 130 and 140 degrees. The footrest is movable along a horizontal axis (H), and its movement is mechanically independent of the seat's movement. (See abstract figure: Figure 2)

Description

Title of the invention: STANDING CHAIR technical field

[0001] The present disclosure falls within the field of standing chairs, that is to say chairs allowing a transition from a seated position to at least a sit-to-stand position, particularly intended for people with reduced mobility and people with disabilities. Previous technique

[0002] People with disabilities who use wheelchairs suffer physiological problems from remaining in a seated position for prolonged periods. Furthermore, they are disadvantaged by not being at the same height as able-bodied people in everyday interactions.

[0003] To address these problems, standing chairs have been developed. They are articulated to allow the user to move from a seated position to a sit-stand or standing position. In the seated position, the user's torso is at approximately 90 degrees to their thighs. In the upright position, the user's torso is at approximately 180 degrees to their thighs. In the sit-stand position, the user is not completely upright, and their torso is at an angle between approximately 90 degrees and approximately 180 degrees. In one embodiment, the sit-stand position presents a torso angle of approximately 135 degrees to the thighs. The seated and sit-stand positions can be optimized for each user.

[0004] The benefits of verticalization can be as follows: by putting weight on the bones, it promotes better growth and helps prevent osteoporosis; it also improves blood circulation, bowel movements, and bladder emptying, thus preventing urinary tract infections. Finally, verticalization prevents skeletal deformities.

[0005] However, the verticalization process can often be uncomfortable for the user due to an often unnatural movement of the body. Summary

[0006] This disclosure improves the situation.

[0007] A standing chair is proposed for a user preferably with a disability or impairment. The chair comprises a seat, a backrest, a footrest; a mechanism for moving the seat adapted to move the chair from a seated position to a sit-stand position and vice versa. In the seated position, an angle act between the spine in a straight position and a line Lp joining the hip joint to the knee joint of the user is between 85 and 100 degrees. In the sit-stand position, the angle is between 130 and 140 degrees. The footrest is movable along a horizontal axis H, and its movement is mechanically independent of the seat's movement.

[0008] The features described in the following paragraphs may optionally be implemented independently of each other or in combination with each other:

[0009] - the footrest is mounted on at least one rail, and in the absence of the user, the The footrest is free to move along the horizontal axis.

[0010] - when the user is seated in the chair with their feet in the footrest In a normal seated position and the seat is set in motion by the seat movement mechanism, the movement of the footrest along the horizontal axis is passively transmitted by the user's body.

[0011] - wherein the chair further comprises a mechanism for setting the footrest to move the footrest along the horizontal axis.

[0012] - the footrest movement mechanism is controllable by the user.

[0013] - the footrest movement mechanism is adapted to move the footrest following the following kinematics:

[0014] [Math.l] d ~ x eùsCa^jj - - (y s2 — (cx sinfœ.))2 +■ x - cxx tanCou,)) - cx sin(O()®u is a distance of the footrest 16 along the horizontal axis H between a position of the footrest when the user is in a seated position and a position of the footrest at a time t between the seated position and the sit-stand position, Le the length of the user's thighs, al the angle of the race line Co of the seat with respect to a vertical axis V, aci is an initial angle of the user's thighs with respect to the horizontal axis, and c is the distance along the race line Co between a position of the hip joint in a seated position and a position of the hip joint at time t between the seated position and the sit-stand position.

[0015] - when the seat changes from the seated position to the sit-stand position, the footrest has a fixed and identical orientation at all times, and the fixed orientation of the footrest is preferably at an angle of 10 degrees relative to the horizontal axis.

[0016] - the footrest is free to pivot around a transverse axis T to the horizontal axis and to a vertical axis.

[0017] - the seat movement mechanism is adapted to move the seat according one along a straight racing line Co having a fixed angle al with respect to a vertical axis V, the angle al being preferably between 8 and 3 degrees, and more preferably 5 degrees.

[0018] - when the seat is set in motion by the movement mechanism of the seat, the seat remains fixed in a horizontal plane.

[0019] - the seat is pivotable about a transverse axis T to the horizontal axis and to an axis vertical V.

[0020] - when the seat is set in motion by the movement mechanism From the seat, the backrest moves along the Co travel line while remaining in a vertical plane. Brief description of the drawings

[0021] Other features, details and advantages will become apparent from reading the detailed description below and from analyzing the accompanying drawings, in which: Fig. 1

[0022] [Fig.1] shows a standing chair with the user in a seated position according to one embodiment. Fig. 2

[0023] [Fig.2] shows the standing chair of [Fig.1] with the user in position sitting-standing. Fig. 3

[0024] [Fig.3] shows a kinematic of the body of a user of the wheelchair in Figures 1 and 8. Fig. 4

[0025] [Fig.4] shows a position of the user's torso when the chair is in the sit-stand position and associated reference angles. Fig. 5

[0026] [Fig.5] shows a position of the user's feet when the chair is in the seated position as well as associated reference angles. Fig. 6

[0027] [Fig.6] shows the footrest of the chair according to one embodiment. Fig. 7

[0028] [Fig.7] shows the seat of the chair according to one embodiment. Description of the implementation methods

[0029] Reference is now made to Figures 1 and 2, which show a standing wheelchair 10 in the seated and sit-to-stand positions respectively, according to one embodiment. In the seated position of the wheelchair 10, the user 20 is seated and a torso 22 of the user 20 (more precisely the spine 25 in a straight position) is at an angle of between 85 and 100 degrees with respect to their thighs. 24 (more precisely a line Lp joining the hip joint 27 to the knee joint 23). [Fig. 1] illustrates a normal seated position of the user 20 in the seated position of the chair 10. In the sit-stand position of the chair 10, the user 20 is almost standing (i.e., almost vertical), with the torso 22 of the user 20 at an angle of between 130 and 140 degrees relative to their thighs 24, preferably at 135 degrees.

[0030] The standing chair 10 can be a wheelchair or a fixed chair. If the chair is wheelchair, it can be motorized or manual. In one embodiment, the chair 10 is a gyropod.

[0031] The chair 10 includes a frame 11 supporting a seat 12 adapted to receive the buttocks and in some cases the thighs 24 of the user 20, a backrest 14 against which the user 20 can lean back and a footrest 16 which receives the feet of the user 20. A mechanism for moving the seat 15 allows the seat 12 to be raised in order to move the chair 10 from the seated position to the sit-stand position, and vice versa.

[0032] To ensure the upright positioning of the chair 10, the seat 12 follows a straight line of travel Co having a fixed angle al with respect to a vertical axis V. In one embodiment, the angle al is between 8 and 3 degrees, preferably 5 degrees. By adopting a non-strictly vertical line of travel Co, the ergonomics of the user 20 are preserved during upright positioning.

[0033] The movement mechanism 15 of the seat 12 can allow the user 20 to be positioned in any intermediate position to the extreme seated and sit-stand positions, following the line of travel Co.

[0034] According to one embodiment, the seat movement mechanism 15 includes a cylinder, such as a hydraulic or pneumatic cylinder, to ensure a straight line of travel. The seat movement mechanism 15 can be controlled by the user 20 for activation and deactivation according to the user's needs.

[0035] The footrest 16 is mobile relative to the seat 12 along a horizontal axis H. Even if the footrest 16 moves between the sitting and sit-stand positions of the chair 10, the movement of the footrest 16 is mechanically independent of that of the seat 12, and remains along the horizontal axis H.

[0036] The vertical V and horizontal H axes are the natural axes defined when the chair 10 is in normal position on the ground.

[0037] According to one embodiment, the footrest 16 is free to move along the horizontal axis H. For example, the footrest 16 is mounted on one or more rails 17 arranged along the horizontal axis H, and is free from constraints along this axis, in the absence of the user 20. That is to say, when the user 20 If the user 20 is not installed in the chair 10, the footrest 16 can move freely along the horizontal axis H. However, when the user 20 is installed in the chair 10, their feet 28 are in the footrest 16, so that when the seat 12 is moved by the seat movement mechanism 15, the body of the user 20 passively transmits this movement via the legs of the user 20. Thus, when the seat 12 rises, the footrest 16 moves backwards along the horizontal axis H passively by the body of the user 20.

[0038] According to another embodiment, the footrest 16 has a movement along the horizontal axis H controlled by a footrest movement mechanism. The footrest movement mechanism is independent of the seat movement mechanism.

[0039] According to one embodiment, the user 20 controls the kinematics of the footrest 16 himself. For example, when he wants to adjust a position of the footrest 16 once he has adjusted the seat 12.

[0040] According to one embodiment, the footrest movement mechanism is programmed to move the footrest 16 according to a kinematic that depends on that of the seat 12 in order to maintain an optimal anatomical position for the user 20. The footrest movement mechanism 16 provides a displacement of the footrest that is mechanically independent of that of the seat, even if the kinematic may depend on that of the seat 12.

[0041] According to one embodiment, the kinematics of the footrest 16 are as follows:

[0042] [Math. 2] to ■- x - k,? - - (ex sîn((ï; 4- x - ex sin(«î)) d is the distance of the footrest 16 along the horizontal axis H between a position of the footrest when the user 20 is seated and a position of the footrest at a time t between the seated position and the sit-stand position. Le is the length of the user 20's thighs 24, al is the angle of the track Co of the seat 16 with respect to the vertical axis V, aci is an initial angle of the user 20's thighs 24 with respect to the horizontal axis H, and c is the distance along the track Co between a position of the hip joint 27 in the seated position and a position of the hip joint 27 at time t between the seated position and the sit-stand position. The distance d varies according to the distance c, which itself varies over time when moving from the seated position to the sit-stand position and vice versa.

[0043] According to one embodiment, whether the movement of the footrest 16 is free or Controlled along the horizontal axis H, the footrest 16 has a fixed orientation (arp angle) that is identical at all times. The fixed orientation of the footrest 16 is preferably at an arp angle between 0 and 15 degrees, preferably at 10 degrees relative to the horizontal axis H. According to one embodiment, and as illustrated in [Fig.5], an angle apt formed by the feet 28 and the tibias 26 of the user 20 is at 90 degrees.

[0044] According to one embodiment, as illustrated in [Fig. 6], whether the movement of the footrest 16 is free or controlled along the horizontal axis H, the footrest 16 is free to pivot about a transverse axis T to the horizontal axis H and a vertical axis V (angle ad). The transverse axis T corresponds to the axis of rotation of the knee joint 23 and the ankle joint of the user 20. This embodiment allows for movement of the footrest 16 when the user 20 is seated, independently of the lifting movement of the seat 12. Considering the lifting movement of the seat 12, the combination of this arrangement of the footrest 16 (pivot) during its horizontal movement improves user 20 comfort, as the footrest 16 automatically positions itself at the optimal angle ad according to the user's load applied to it.

[0045] According to one embodiment, whether the movement of the footrest 16 is free or controlled along the horizontal axis H, the seat 12 remains fixed in a horizontal plane during its verticalization movement.

[0046] According to another embodiment, as illustrated in [Fig. 7], whether the movement of the footrest 16 is free or controlled along the horizontal axis H, the seat 12 can pivot about the transverse axis T to the horizontal axis H and a vertical axis V (angle ab). This transverse axis T corresponds to the hip joint 27 of the user 20. The pivot of the seat 12 about the transverse axis T can be free or controlled. Considering the lifting movement of the seat 12, the combination of the pivoting of the seat 12 with its lifting improves user comfort, as the seat 12 automatically positions itself at the optimal angle according to the load applied to the user 20.

[0047] In the embodiments presented above, the backrest 14 can be fixedly connected to the seat 12. In this case, the backrest 14 moves along the line of travel Co, while remaining in a vertical plane.

[0048] The kinematics developed in the embodiments presented allow the center of gravity of the user 20 to evolve during lifting along a perfectly vertical line. In the case of a gyropod base for the wheelchair 10, this ensures that the movement will have no influence on the stability of the base.

[0049] The angles presented in this application must be considered with their margin of tolerance as is customary in the technical field of the invention.

Claims

Demands

1. Standing chair (10) for a user (20) preferably in a situation of disability or invalidity, the chair comprising: - a seat (12), a backrest (14), a footrest (16); and - a mechanism for moving the seat (15) adapted to move the chair from a seated position to a sit-stand position and vice versa, in the seated position an angle act between the spine (25) in a straight position and a line Lp joining the hip joint (27) to the knee joint (23) of the user is between 85 and 100 degrees, in the sit-stand position the angle act is between 130 and 140 degrees, characterized in that the footrest is mobile along a horizontal axis H, and a movement of the footrest is mechanically independent of the movement of the seat.

2. Armchair according to claim 1, in which the footrest is mounted on at least one rail (17), and in the absence of the user, the footrest is free to move along the horizontal axis.

3. Armchair according to claim 2, wherein when the user is seated in the armchair with feet in the footrest in normal seated position and the seat is set in motion by the seat movement mechanism, the movement of the footrest along the horizontal axis is passively transmitted by the user's body.

4. Armchair according to claim 1, further comprising a mechanism for moving the footrest to move the footrest along the horizontal axis.

5. Armchair according to claim 4, wherein the footrest movement mechanism is user-controllable.

6. Armchair according to claim 4, wherein the footrest movement mechanism is adapted to move the footrest according to the following kinematics: [Math. 3] æ 1... x — (^^ — (çx ))- 4 XJ — • xxj) — cx suifs. ) OR d is a distance of the footrest 16 along the horizontal axis H between a position of the footrest when the user is seated and a position of the footrest at a time t between the position seated and the sit-to-stand position, Le the length of the user's thighs (24), al the angle of the line of travel Co of the seat with respect to a vertical axis V, aci is an initial angle of the user's thighs with respect to the horizontal axis H, and c is the distance along the line of travel Co between a position of the hip joint in the seated position and a position of the hip joint at time t between the seated position and the sit-to-stand position.

7. Armchair according to any one of claims 1 to 6, wherein when the seat changes from the seated position to the sit-stand position, the footrest has a fixed and identical orientation at all times, and the fixed orientation of the footrest is preferably at an angle a rp of 10 degrees with respect to the horizontal axis.

8. Armchair according to any one of claims 1 to 6, wherein the footrest is free to pivot about a transverse axis T to the horizontal axis and to a vertical axis.

9. Armchair according to any one of the preceding claims, wherein the seat movement mechanism is adapted to move the seat along a straight line of travel Co having a fixed angle al with respect to a vertical axis V, the angle al being preferably between 8 and 3 degrees, and more preferably 5 degrees.

10. Armchair according to any one of claims 1 to 9, wherein when the seat is set in motion by the seat-setting mechanism, the seat remains fixed in a horizontal plane.

11. Armchair according to any one of claims 1 to 9, wherein the seat is pivotable about a transverse axis (T) to the horizontal axis and to a vertical axis (V).

12. Armchair according to any one of the preceding claims, wherein when the seat is set in motion by the seat-setting mechanism, the backrest moves along the line of travel Co while remaining in a vertical plane.

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