EP4659727A1

EP4659727A1 - Leg rest assembly for a wheelchair

Info

Publication number: EP4659727A1
Application number: EP24179557.4A
Authority: EP
Inventors: Håkan BERGMAN; Jonas Jähkel; Johnny Nordin
Original assignee: Permobil AB
Current assignee: Permobil AB
Priority date: 2024-06-03
Filing date: 2024-06-03
Publication date: 2025-12-10
Also published as: WO2025252525A1

Abstract

A leg rest assembly (1) for a wheelchair, comprising: an elongated outer profile (3), a foot support connected to the outer profile (3), an elongated inner profile (5) having a longitudinal axis and being at least partly received by the outer profile (3), the inner profile (5) and outer profile (3) being movably arranged relative to each other, a linkage arm (7) arranged to be pivotally connected to a wheelchair, a motor drive system (11), a first carrier unit fixedly connected to the outer profile (3), and a second carrier unit pivotally connected to the linkage arm (7) to form a pivot axis, wherein the motor drive system (11) is configured to move the first carrier unit inside the inner profile (5) parallel with the longitudinal axis, thereby moving the outer profile (3) axially relative to the inner profile (5), to adjust an extension of the leg rest assembly (1), and wherein the motor drive system (11) is configured to move the second carrier unit inside the inner profile (5) along the longitudinal axis, whereby the pivot axis between the linkage arm (7) and the second carrier unit is moved along the inner profile (5).

Description

TECHNICAL FIELD

The present disclosure generally relates to leg rest assemblies for wheelchairs.

BACKGROUND

Wheelchairs may often have a leg rest equipped with a foot support. The leg rest may be pivotably connected to the wheelchair to allow for the leg rest to pivot between a lowered and a raised or elevated position.
In the event that the pivot coupling of the leg rest is offset from the knee joint, the foot support may drive the user's feet towards their knee when the leg rest is in the raised position. Pivotable leg rests are therefore often extendable, to eliminate this effect. In particular, the leg rest may be set in an extended position when the leg rest is in the raised or elevated position as compared to its extension in the lowered position. An example of such a leg rest is disclosed in US 2006/0086202 A1 . This document discloses a leg rest that comprises a single motor that drives a pulley connected to a lead screw having one portion provided with threads of a larger pitch than another portion of the lead screw. Moreover, the two threads have opposite handedness. The two portions of the lead screw are connected to a respective housing, which, due to the thread structure, when the motor is driven causes the two housings to move either away from each other or towards each other, at different speed. This movement causes extension/retraction, and rotation, of the leg rest.

SUMMARY

A general object of the present disclosure is to provide a leg rest assembly for a wheelchair which solves or at least mitigates the problems of the prior art.
There is hence according to a first aspect of the present disclosure provided a leg rest assembly for a wheelchair, comprising: an elongated outer profile, a foot support connected to the outer profile, an elongated inner profile having a longitudinal axis and being at least partly received by the outer profile, the inner profile and outer profile being movably arranged relative to each other, a linkage arm arranged to be pivotally connected to a wheelchair, a motor drive system, a first carrier unit fixedly connected to the outer profile, and a second carrier unit pivotally connected to the linkage arm to form a pivot axis, wherein the motor drive system is configured to move the first carrier unit inside the inner profile parallel with the longitudinal axis, thereby moving the outer profile axially relative to the inner profile, to adjust an extension of the leg rest assembly, and wherein the motor drive system is configured to move the second carrier unit inside the inner profile along the longitudinal axis, whereby the pivot axis between the linkage arm and the second carrier unit is moved along the inner profile.
The first and the second carrier units are arranged to move inside the inner profile. The first carrier unit and the second carrier unit are thus better protected from e.g., dust and dirt than the open first and second members disclosed in US 2006/0086202 A1 .
The extension of the leg rest assembly in relation to the pivot point of a user's knee can be kept constant irrespective of the angle of orientation of the leg rest assembly in relation to a wheelchair to which it has been mounted.
The motor drive system may be fixedly attached to the inner profile.
The inner profile may comprise a slot extending axially along the longitudinal axis of the inner profile, wherein the linkage arm may extend from the second carrier unit through the slot.
According to one embodiment the first carrier unit is configured to run between a first position and a second position inside the inner profile, wherein the first position is closer to a top end of the inner profile than the second position, wherein the second carrier unit is configured to run between a third position and a fourth position in the inner profile, wherein the third position is closer to the top end than the fourth position, wherein in a first extreme position of the leg rest assembly, the first carrier unit is in the second position, and the second carrier unit is in the third position, and wherein in a second extreme position of the leg rest assembly, the first carrier unit is in the first position and the second carrier unit is in the fourth position.
One embodiment comprises a first bearings arranged between the inner profile and the outer profile to facilitate linear movement between the inner profile and the outer profile.
One embodiment comprises a second bearings arranged between the second carrier unit and the inner profile to facilitate linear movement between the second carrier unit and the inner profile.
One embodiment comprises a first lead screw extending axially inside the inner profile, the first lead screw being threadedly connected to the first carrier unit, wherein the first lead screw is configured to be driven by the motor drive system.
One embodiment comprises a plate structure, wherein each of the outer profile and the first carrier unit is fixedly connected to the plate structure, and wherein movement of the first carrier unit by the motor drive system causes the plate structure to move relative to the inner profile, resulting in axial movement of the outer profile relative to the inner profile.
According to one embodiment the plate structure is connected to a lower end of the outer profile.
One embodiment comprises a second lead screw extending axially inside the inner profile, the second lead screw being threadedly connected to the second carrier unit, wherein the second lead screw is configured to be driven by the motor drive system.
The first lead screw and the second lead screw are two distinct screws, arranged in parallel, beside each other.
According to one embodiment the motor drive system comprises one or two electric motors, each electric motor being fixedly mounted to the inner profile.
According to one embodiment the motor drive system comprises a single electric motor, and a single drive assembly configured to transfer rotational motion from the single electric motor to drive the first carrier unit and the second carrier unit.
According to one embodiment the motor drive system comprises two electric motors, a first drive assembly, and a second drive assembly, the first drive assembly being configured to transfer rotational motion from a first of the electric motors to motion to drive the first carrier unit and the second drive assembly being configured to transfer rotational motion from a second of the electric motors to motion to drive the second carrier unit.
The first carrier unit and the second carrier unit may thus be individually and separately driven by the motor drive system. This allows for individual control of moving the pivot axis along the inner profile, i.e., angulation of the leg rest assembly when mounted to a wheelchair, by controlling the position of the second carrier unit, and adjusting the extension of the leg rest assembly by controlling the position of the first carrier unit.
One embodiment comprises a mount for mounting the inner profile to a wheelchair, the mount comprising a bearing to facilitate pivoting of the leg rest assembly relative to the wheelchair.
There is according to a second aspect of the present disclosure provided a wheelchair comprising a leg rest assembly according to the first aspect.
One embodiment comprises a seating system, wherein the linkage arm is pivotally connected to the seating system, wherein movement of the pivot axis along the inner profile causes a change of an angle of the inner profile and the outer profile relative to the seating system.
According to one embodiment the seating system comprises a seat and a lift and tilt device supporting the seat, the lift and tilt device comprising a support element arranged to be pivotable about a lift and tilt device pivot axis, wherein the leg rest assembly is arranged to allow pivoting of the leg rest assembly relative to the lift and tilt device about the lift and tilt device pivot axis by movement of the second carrier unit.
According to one embodiment the leg rest assembly is connected to the pivot axle in the median plane of the wheelchair.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means", etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, etc., unless explicitly stated otherwise.

BRIEF DESCRIPTION OF THE DRAWINGS

The specific embodiments of the inventive concept will now be described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a sideview of a leg rest assembly in a retracted state;
Fig. 2 is a sideview of the leg rest assembly in Fig. 1 in an extended state;
Figs 3A-3C show the leg rest assembly in Fig. 1 in the retracted state without its inner and outer profiles;
Fig. 4 is a perspective view of a cross-section along lines A-A of the leg rest assembly in Fig. 6;
Fig. 5 shows the leg rest assembly in the extended state without its inner and outer profiles;
Fig. 6 is a side view of the leg rest assembly in its extended state;
Fig. 7 is a cross-section along lines B-B of the leg rest assembly in Fig. 6;
Fig. 8 is a cross-section along lines C-C of the leg reast assembly in Fig. 6;
Figs 9A-9B shows the leg rest assembly with foot support, in lowered, and raised positions, respectively, when connected to a component of a wheelchair; and
Fig. 10 is a perspective view of an example of a wheelchair comprising a leg rest assembly.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which exemplifying embodiments are shown. The inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description.
Fig. 1 shows an example of a leg rest assembly 1 for a wheelchair, such as a power wheelchair.
The leg rest assembly 1 is configured to be actuated to attain a retracted state, shown in Fig. 1, and an extended state, shown in Fig. 2. as well as all states therebetween.
The leg rest assembly 1 is configured to be actuated to attain a lowered position in relation to a wheelchair, and a raised or elevated position, in which an angle of the leg rest assembly 1 is changed relative to the wheelchair. The leg rest assembly 1 can also attain all angular positions between the lowered position and the raised position.
Turning now to Fig. 2, the leg rest assembly 1 comprises an elongated outer profile 3.
The leg rest assembly 1 comprises an elongated inner profile 5. The inner profile 5 has a longitudinal axis.
The outer profile 3 has a longitudinal axis.
The inner profile 5 and the outer profile 3 are arranged parallel with each other. The longitudinal axis of the inner profile 5 and the longitudinal axis of the outer profile 3 are thus parallel.
The inner profile 5 is at least partly received by the outer profile 3.
The inner profile 5 and the outer profile 3 are arranged to slide relative to each other. The outer profile 3 is arranged to slide telescopically relative to the inner profile 5. A larger portion of the inner profile 5 is received by the outer profile 3 when the leg rest assembly 1 is in the retracted state than in the extended state.
The leg rest assembly 1 comprises a linkage arm 7. The linkage arm 7 is pivotable in relation to the inner profile 5 and in relation to the outer profile 3.
The leg rest assembly 1 may comprise a bracket 9 pivotally connected to one end of the linkage arm 7. The bracket 9 is configured to be connected to a wheelchair.
The leg rest assembly 1 comprises a motor drive system 11. The motor drive system 11 may comprise one or more than one electric motor 12.
The motor drive system 11 may be fixedly arranged relative to the inner profile 5.
The motor drive system 11 may comprise a transmission box 13. The transmission box 13 may comprising one or two drive assemblies.
The motor drive system 11 is configured to adjust the degree of extension of the leg rest assembly 1 and to adjust a position of the linkage arm 7 relative to the inner profile 5. The angle of the linkage arm 7 in relation to the inner profile 5 and the outer profile 3, and if present, in relation to the bracket 9, can thus be adjusted.
The transmission box 11 may be mounted to one end of the inner profile 5.
The leg rest assembly 1 may comprise a mount 15. The mount 15 may be arranged on top of the transmission box 13. The mount 15 may form one axial end of the leg rest assembly 1. The mount 15 is for connecting the leg rest assembly 1 to a wheelchair.
The mount 15 may have a through-opening 17 which extends in a direction perpendicular to the longitudinal axis of the inner profile 5. The mount 15 may comprise a bearing 19 arranged in the through-opening 17. The bearing 19 may be a slide bearing.
The leg rest assembly 1 may have two separate connections for connection with a wheelchair, namely the mount 15 and the bracket 9.
Fig. 3A shows a front view of the leg rest assembly 1 without the inner profile 5 and the outer profile 3, to expose internal components of the leg rest assembly 1. Fig, 3B shows the leg rest assembly 1 in Fig. 3A in a perspective view.
The leg rest assembly 1 comprises a first carrier unit 21. The first carrier unit 21 is fixedly connected to the outer profile 3.
The first carrier unit 21 may be a tube.
The motor drive system 11 is configured to move the first carrier unit 21, bringing with it the outer profile 3. The outer profile 3 can thereby be moved linearly in relation to the inner profile 5. The degree of extension of the leg rest assembly 1 may thereby be set.
The leg rest assembly 1 may comprise a plate structure 3a. The plate structure 3a is fixedly connected to a lower end of the outer profile 3.
The first carrier unit 21 maybe fixedly connected to the plate structure 3a. For example, one end of the first carrier unit 21, furthest away from the transmission box 13, may be fixedly connected to the plate structure 3a. Thus, when the first carrier unit 21 is moved by the motor drive system 11, the plate structure 3a, and thus the outer profile 3, is translated by the first carrier unit 21.
The leg rest assembly 1 comprises a second carrier unit 23. The linkage arm 7 is pivotally connected to the second carrier unit 23. A pivot axis 25, shown in Fig. 3B, is thereby formed between the second carrier unit 23 and the linkage arm 7. The linkage arm 7 has a proximal end, which is pivotally connected to the second carrier unit 23, forming the pivot axis 25. The linkage arm 7 has a distal end which is pivotally connected to the bracket 9, or which can be directly connected to a wheelchair in examples without the bracket 9.
As the second carrier unit 23 is moved inside the inner profile 5, the pivot axis 25 is moved concurrently in relation to the inner profile 5. The position of the proximal end of the linkage arm 7 is thus moved along the inner profile 5. The angle of the linkage arm 7 relative to the longitudinal axis of the inner profile 5 may thereby be adjusted. This is especially the case when the leg rest assembly 1 has been mounted to a wheelchair, because then the distal end of the linkage arm 7, directly or via the bracket 9, is attached to the wheelchair and the mount 15 is also attached to the wheelchair.
The inner profile 5 may have a slot extending axially along a longitudinal axis of the inner profile 5. The slot may be a rear slot, i.e., at a rear face of the inner profile 5, facing in the same direction as the extension of the linkage arm 7. The linkage arm 7 may extend from the second carrier unit 5 through the slot. The slot may be dimensioned to be so narrow that it allows for the linkage arm 7 to extend through it with a predefined manufacturing tolerance.
Fig. 3C shows the leg rest assembly 1 without the first carrier unit 21 and the second carrier unit 23. The leg rest assembly 1 comprises a first lead screw 27.
The first lead screw 27 is arranged in the inner profile 5. The first lead screw 27 is configured to be driven by the motor drive system 11. The first lead screw 27 is thus configured to be rotated by the motor drive system 11. The first lead screw 27 extends parallel with the longitudinal axis of the outer profile 3.
The first lead screw 27 may have threads with a first pitch. The first lead screw 27 may have threads with a first helix angle.
The first lead screw 27 is threadedly connected to the first carrier unit 21. Rotation of the first lead screw 27 causes the first carrier unit 21 to move along the first lead screw 27. The threaded connection may be direct or indirect. According to the example shown in Fig. 3C, the leg rest assembly 1 comprises a first nut 29 arranged around the first lead screw 27. The first nut 29 is in direct threaded engagement with the first lead screw 27. The first nut 29 is connected to the first carrier unit 21. The connection between the first nut 29 and the first carrier unit 21 is rotationally fixed. For example, the first nut 29 may have one or more radial recess or cut-out, and the first carrier unit 21 may have an inner surface provided with a corresponding number of radial inwards extending protrusions, each engaging with a respective recess or cut-out. Alternatively, the inner surface of the first carrier unit 21 may be provided with one or more radial recess or cut-out and the first nut 29 may comprise a corresponding number of radially outwards extending protrusions, each engaging with a respective recess or cut-out. Alternatively, the first nut 29 and the first carrier unit 21 may be rotationally locked by means of splines or other means known to the skilled person.
The leg rest assembly 1 comprises a second lead screw 31. The second lead screw 31 is arranged in the inner profile 5. The second lead screw 31 is configured to be driven by the motor drive system 11. The second lead screw 31 is thus configured to be rotated by the motor drive system 11. The second lead screw 31 extends parallel with the longitudinal axis of the inner profile 5.
The second lead screw 31 is threadedly connected to the second carrier unit 23. Rotation of the second lead screw 31 causes the second carrier unit 23 to move along the second lead screw 31. The threaded connection may be direct or indirect. According to the example shown in Fig. 3C, the leg rest assembly 1 comprises a second nut 33 arranged around the second lead screw 31. The second nut 33 is in direct threaded engagement with the second lead screw 31. The second nut 33 is connected to the second carrier unit 23. The connection between the second nut 31 and the second carrier unit 23 is rotationally fixed. For example, the second nut 33 may have one or more radial recess or cut-out, and the second carrier unit 23 may have an inner surface provided with a corresponding number of radial inwards extending protrusions, each engaging with a respective recess or cut-out. Alternatively, the inner surface of the second carrier unit 23 may be provided with one or more radial recess or cut-out and the second nut 33 may comprise a corresponding number of radially outwards extending protrusions, each engaging with a respective recess or cut-out. Alternatively, the second nut 33 and the second carrier unit 23 may be rotationally locked by means of splines or other means known to the skilled person.
The second lead screw 31 may have threads with a second pitch. The second pitch may be smaller than the first pitch.
The second lead screw 31 may have threads with a second helix angle. The second helix angle may be smaller than the first helix angle. Thus, if the first lead screw 27 and the second lead screw 31 are rotated simultaneously at the same speed by the motor drive system 11, the first carrier unit 21 will move faster along the first lead screw 27 than the second carrier unit 23 will along the second lead screw 31.
Fig. 4 is a cross-section of the leg rest assembly 1 along lines A-A shown in Fig. 6.
According to the example, the motor drive system 11 comprises two electric motors 12. Alternatively, the motor drive system 11 could comprise a single electric motor 12.
Each electric motor 12 may be fixedly mounted to the inner profile 5. All the electric motors 12 may be connected to the transmission box 13, which is fixedly connected to the inner profile 5.
In the example with two electric motors 12, each electric motor 12 is configured to drive a respective one of the first lead screw 27 and the second lead screw 31.
According to the example in Fig. 4, the transmission box 13 comprises a first drive assembly 11a, and a second drive assembly 11b.
The first drive assembly 11a is configured to transfer rotational motion from a first of the electric motors 12 to motion to drive the first carrier unit 21. In particular, the first drive assembly 11a is configured to cause rotation of the first lead screw 27. The first drive assembly 11a comprises a first force transfer means 11c, such as gears, a belt, a chain, or a worm drive, which connects the rotor shaft of one of the electric motors 12 with the first lead screw 27.
The second drive assembly 11b is configured to transfer rotational motion from a second of the electric motors 12 to motion to drive the second carrier unit 23. In particular, the second drive assembly 11b is configured to cause rotation of the second lead screw 31. The second drive assembly 11b comprises a second force transfer means 11d, such as gears, a belt, a chain, or a worm drive, which connects the rotor shaft of the other one of the electric motors 12 with the second lead screw 31.
As an alternative to the above, in case the motor drive system 11 comprises a single electric motor, the single drive assembly may comprise a single force transfer means, such as gears, a belt, a chain, or a worm drive, which drives both the first lead screw 27 and the second lead screw 31.
Fig. 5 shows the leg rest assembly 1 in its extended state, with the inner profile 5 and the outer profile 3 removed.
The first carrier unit 21 is configured to run between a first position, shown in Figs 3A-B, and a second position, shown in Fig. 5. The first carrier unit 21 is closer to the to the top end of the inner profile 5 in the first position than in the second position. The first carrier unit 21 is closer to the transmission box 13 in the first position than in the second position. The first carrier unit 21 essentially receives the entire first lead screw 27 when the first carrier unit 21 is in the first position. In the second position, a large portion of the first carrier unit 21 has essentially moved out from the inner profile 5. Thus, in the second position, the majority of the first carrier unit 21 is arranged outside the inner profile 5. The top part of the first carrier unit 21, closest to the transmission box 13, may, depending on the implementation which in turn may depend on the user, have moved along approximately the entire length of the first lead screw 27 when the first carrier unit 21 is in the second position.
The second carrier unit 23 is configured to run between a third position and a fourth position in the inner profile 5. The third position is closer to the top end of the inner profile 5 than the fourth position.
A first extreme position of the leg rest assembly 1 is shown in Fig. 5. In the first extreme position the leg rest assembly 1 is in the raised position and in an extended state. The first carrier unit 21 is in this case in the second position, and the second carrier unit 23 is in the third position. In a second extreme position of the leg rest assembly 1 shown in Figs 3A-C, the leg rest assembly 1 is in the lowered position and in a retracted state. The first carrier unit 21 is in this case in the first position and the second carrier unit 23 is in the fourth position.
Fig. 7 shows a cross-section of the leg rest assembly 1 along lines B-B in Fig. 6. The leg rest assembly 1 may comprise first bearings 35 arranged between the inner profile 5 and the outer profile 3 to facilitate linear movement between the inner profile 5 and the outer profile 3. The first bearings 35 may be slide bearings.
Fig. 8 shows a cross-section of the leg rest assembly 1 along lines C-C in Fig. 6. The leg rest assembly 1 may comprise second bearings 37 arranged between the second carrier unit 23 and the inner profile 5 to facilitate linear movement between the second carrier unit 23 and the inner profile 5. The second bearings 37 may be slide bearings.
As can be seen in Figs 7-8, the inner profile 5 may be circumferentially closed, or essentially circumferentially closed. For example, the inner profile 5 may have the aforementioned axial slot, through which the linkage arm 7 extends. The outer profile 3 may be circumferentially closed, or essentially circumferentially closed. The outer profile 3 may also comprise a slot, which is axially aligned with the slot of the inner profile 5 to allow the linkage arm 7 to extend through both the inner profile 5 and the outer profile 3 when the leg rest assembly 1 is in a retracted state.
Figs 9A-9B show the leg rest assembly 1 when it has been mounted to a support element or beam 39 of a lift and tilt device of a wheelchair. Only the support element 39 of the tilt and lift device is shown in the drawings.
The linkage arm 7 is connected to the support element 39. The bracket 9 may be connected directly to the support element 39. The bracket 9 may be connected to an underside of the support element 39. The bracket 9 may be fixedly connected to the underside of the support element 39.
The leg rest assembly 1 is pivotably connected to the support element 39 by means of the mount 15. The inner profile 5 is pivotably connected to the support element 39 via the mount 15.
The support element 39 may be elongated. The support element 39 may have a longitudinal axis that coincides with the median plate of the wheelchair.
In Fig. 9A, the leg rest assembly 1 is in a retracted state and the lowered position. The inner profile 5 and the outer profile 3 are thus at an angle which may be 90° or approximately 90° relative to the upper beam 39.
In Fig. 9B, the leg rest assembly 1 is in an extended state and the fully raised or elevated position. The inner profile 5 and the outer profile 3 may be arranged essentially parallel with the support element 39.
The leg rest assembly 1 comprises a foot support 41. The foot support 41 is connected to the outer profile 3. The foot support 41 is moved together with the outer profile 3 when the outer profile is moved in relation to the inner profile 5, and when the leg rest assembly 1 is actuated between the raised and lowered positions.
Fig. 10 shows an example of a wheelchair 43. The wheelchair 43 may be a power wheelchair.
The wheelchair 43 is according to the example a front-wheel drive wheelchair. The wheelchair 43 could alternatively be a mid-wheel drive wheelchair, a rear-wheel drive wheelchair, or a four-wheel drive wheelchair.
The wheelchair 43 comprises the leg rest assembly 1. Further, the wheelchair 43 comprises a seating system 45. The seating system 45 comprises a seat 45a and a backrest 45b.
The wheelchair 43 may comprise a lift and tilt device. The lift and tilt device may form part of the seating system. The lift and tilt device supports the seat 45a.
The lift and tilt device may comprise the support element 39, which may be arranged to be pivotable about a lift and tilt device pivot axis 40, shown in Fig. 9A, for enabling tilting of the seat 45a supported by the support element 39. The leg rest assembly 1 is connected to the support element 39 and arranged to allow pivoting of the inner profile 5 relative to the lift and tilt device about the lift and tilt device pivot axis 40, by movement of the second carrier unit 23.
The wheelchair 43 may comprise a control system configured to control the state and position of the leg rest assembly 1 by controlling the motor drive system 11.
In operation of the wheelchair 43 raising the leg rest assembly 1 to the raised position involves pivoting the leg rest assembly 1 to elevate the lower legs of the wheelchair user.
As an alternative to the leg rest assembly1 being mounted to an element of the lift and tilt device, the leg rest assembly 1 may be pivotally connected to the seat 45a, with the linkage arm 7 being fixedly connected to the seat 45a or to an element of the lift and tilt device.
As an alternative to an outer profile that is movable in relation to the mount, the inner profile could be movable, and the outer profile could be fixed in relation to the mount.
The inventive concept has mainly been described above with reference to a few examples. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.

Claims

Leg rest assembly (1) for a wheelchair (43), comprising:
an elongated outer profile (3),

a foot support (41) connected to the outer profile (3),

an elongated inner profile (5) having a longitudinal axis and being at least partly received by the outer profile (3), the inner profile (5) and outer profile (3) being movably arranged relative to each other,

a linkage arm (7) arranged to be pivotally connected to a wheelchair (43),

a motor drive system (11),

a first carrier unit (21) fixedly connected to the outer profile (3), and

a second carrier unit (23) pivotally connected to the linkage arm (7) to form a pivot axis (25),

wherein the motor drive system (11) is configured to move the first carrier unit (21) inside the inner profile (5) parallel with the longitudinal axis, thereby moving the outer profile (3) axially relative to the inner profile (5), to adjust an extension of the leg rest assembly (1), and

wherein the motor drive system (11) is configured to move the second carrier unit (23) inside the inner profile (5) along the longitudinal axis, whereby the pivot axis (25) between the linkage arm (7) and the second carrier unit (23) is moved along the inner profile (5).
Leg rest assembly (1) as claimed in claim 1, wherein the first carrier unit (23) is configured to run between a first position and a second position inside the inner profile (5), wherein the first position is closer to a top end of the inner profile (5) than the second position, wherein the second carrier unit (23) is configured to run between a third position and a fourth position in the inner profile (5), wherein the third position is closer to the top end than the fourth position, wherein in a first extreme position of the leg rest assembly (1), the first carrier unit (21) is in the second position, and the second carrier unit (23) is in the third position, and wherein in a second extreme position of the leg rest assembly (1), the first carrier unit (21) is in the first position and the second carrier unit (23) is in the fourth position.
Leg rest assembly (1) as claimed in claim 1 or 2, comprising first bearings (35) arranged between the inner profile (5) and the outer profile (3) to facilitate linear movement between the inner profile (5) and the outer profile (3).
Leg rest assembly (1) as claimed in any of the preceding claims, comprising second bearings (37) arranged between the second carrier unit (23) and the inner profile (5) to facilitate linear movement between the second carrier unit (23) and the inner profile (5).
Leg rest assembly (1) as claimed in any of the preceding claims, comprising a first lead screw (27) extending axially inside the inner profile (5), the first lead screw (27) being threadedly connected to the first carrier unit (21), wherein the first lead screw (27) is configured to be driven by the motor drive system (11).
Leg rest assembly (1) as claimed in any of the preceding claims, comprising a plate structure (3a), wherein each of the outer profile (3) and the first carrier unit (21) is fixedly connected to the plate structure (3a), and wherein movement of the first carrier unit (21) by the motor drive system (11) causes the plate structure (3a) to move relative to the inner profile (5), resulting in axial movement of the outer profile (3) relative to the inner profile (5).
Leg rest assembly (1) as clamed in claim 6, wherein the plate structure (3a) is connected to a lower end of the outer profile (3).
Leg rest assembly (1) as claimed in any of the preceding claims, comprising a second lead screw (31) extending axially inside the inner profile (5), the second lead screw (31) being threadedly connected to the second carrier unit (23), wherein the second lead screw (31) is configured to be driven by the motor drive system (11).
Leg rest assembly (1) as claimed in any of the preceding claims, wherein the motor drive system (11) comprises one or two electric motors (12), each electric motor (12) being fixedly mounted to the inner profile (5).
Leg rest assembly (1) as claimed in claim 9, wherein the motor drive system (11) comprises a single electric motor (12), and a single drive assembly (11a, 11b) configured to transfer rotational motion from the single electric motor (12) to drive the first carrier unit (21) and the second carrier unit (23).
Leg rest assembly (1) as claimed in claim 9, wherein motor drive system (11) comprises two electric motors (12), a first drive assembly (11a), and a second drive assembly (11b), the first drive assembly (11a) being configured to transfer rotational motion from a first of the electric motors (12) to motion to drive the first carrier unit (21) and the second drive assembly (11b) being configured to transfer rotational motion from a second of the electric motors (12) to motion to drive the second carrier unit (23).
Leg rest assembly (1) as claimed in any of the preceding claims, comprising a mount (15) for mounting the inner profile (5) to a wheelchair (43), the mount (15) comprising a bearing (19) to facilitate pivoting of the leg rest assembly (1) relative to the wheelchair (43).
Wheelchair (43) comprising a leg rest assembly (1) as claimed in any of the preceding claims.
Wheelchair (43) as claimed in claim 13, comprising a seating system (54), wherein the linkage arm is pivotally connected to the seating system, wherein movement of the pivot axis along the inner profile causes a change of an angle of the inner profile (5) and the outer profile (3) relative to the seating system (45).
Wheelchair (43) as claimed in claim 14, wherein the seating system comprises a seat and a lift and tilt device supporting the seat (45a), the lift and tilt device comprising a support element (39) arranged to be pivotable about a lift and tilt device pivot axis (40), wherein the leg rest assembly is arranged to allow pivoting of the leg rest assembly (1) about the lift and tilt device pivot axis (40) by movement of the second carrier unit (23).
Wheelchair (43) as claimed in claim 15, wherein the leg rest assembly (1) is connected to the support element (39) in the median plane of the wheelchair (43).