WO2016034755A1

WO2016034755A1 - Drive device for active orthosis

Info

Publication number: WO2016034755A1
Application number: PCT/ES2015/070646
Authority: WO
Inventors: Josep Maria FONT LLAGUNES; Daniel CLOS COSTA
Original assignee: Universitat Politècnica De Catalunya
Priority date: 2014-09-03
Filing date: 2015-09-03
Publication date: 2016-03-10
Also published as: ES2562340A1; ES2562340B1

Abstract

The invention relates to an actuating device for active orthosis, which includes proximal and distal brackets (1, 2) to be attached to proximal and distal parts of the orthosis, respectively. The proximal and distal brackets (1, 2) are connected to one another by a supporting joint (3). A screw (5) operatively connected such as to be turned by an electric motor (4), a runner (10) movable along linear guides (11) parallel to the screw (5), and a nut (9) attached to the runner (10) and connected to the screw (5) are installed in the proximal bracket (1). A connecting rod (6) has a first end connected to the runner (10) via a proximal joint (7) and a second end connected to the distal bracket (2) via a distal joint (8). The connecting rod (6) converts the movement of the runner (10) into a turn of the distal bracket (2) around the supporting joint (3).

Description

MOTORIZATION DEVICE FOR OR ACTIVE RTESIS

DESCRIPTION

Field of the art The present invention concerns a motorization device for an active leg brace that includes a joint, and especially though not exclusively for an active brace that includes a knee joint, the motorization device comprising an electric motor and a mechanical transmission to drive the movement of the joint. Background of the invention

In documents [1] and [2] a SCKAFO (Stance Control Knee Ankle Foot Orthosis) type orthosis device is described, which includes a joint in the knee and another in the ankle, intended to assist the march, where the joint The knee is driven by an electric motor in cooperation with a three-stage epicyclic reducer that has a transmission ratio of 186: 1. In one embodiment, the output shaft of the epicycloidal reducer is connected directly to the axis of the knee joint, the motor-reducer assembly being protruding outwardly with its axis in a direction perpendicular to the sagittal plane, and therefore perpendicular to the longitudinal direction of the leg, which has the drawback that can be a hindrance. In another embodiment, the output shaft of the epicycloidal reducer is connected to the axis of the knee joint by means of a right angle forwarding comprising two conical sprockets with a 1: 1 transmission ratio. However, both embodiments have the disadvantage of needing an epicyclic reducer of very high transmission ratio. US 20140094345 A1 discloses an active orthosis that includes a knee joint and a motorization device to drive the movements of this knee joint. The motorization device comprises an electric gearmotor assembly fixed to a part of the orthosis corresponding to the thigh, and an extensible spindle connected at its end to a part of the orthosis corresponding to the leg, and a nut coupled to the spindle and actuated by the assembly electric gearmotor References

[1] Sistiaga Vidal-Ribas, Javier. "Disseny mechanic d'una ortesi activates per a lesionats medul lars from the dynamic analysis of the human marxa." Master thesis Universitat Politècnica de Catalunya. December 2012. [2] Font-Llagunes, Josep M .; Pámies-Vilá, Rosa; Alonso, Javier; and Lugrís, Urban. "Simulation and design of an active orthosis for an incomplete spinal cord injured subject" 2011 Symposium on Human Body Dynamics. Elsevier, Procedure IUTAM 2 (2011) 68-81.

Exhibition of the invention

The present invention constitutes an alternative to the state of the art, by providing a drive device that provides a compact and lightweight design, increased transmission performance, reduced angular play, and the possibility of actuation and blocking. The drive device for active brace of the present invention comprises a proximal support intended to be fixed to a proximal part of the orthosis and a distal support intended to be fixed to a distal part of the orthosis, wherein said proximal and distal supports are connected to each other by a support joint having an axis of rotation aligned in use with an axis of articulation between said proximal and distal parts of the orthosis. The drive device includes a mechanism connected to the proximal and distal supports and driven by an electric motor fixed to the proximal support to rotate the distal support relative to the proximal support around said rotation axis.

Said mechanism comprises, according to the present invention, a spindle rotatably supported on the proximal support and operatively connected to be rotated by said electric motor, a movable slide along at least one linear guide parallel to said spindle and supported on the proximal support, a nut fixed to said slide and coupled to the spindle, and a connecting rod having a first end connected to the slide by a proximal joint and a second end connected to the distal support by a distal joint.

Throughout this description, the term "articulation" is used to cover both a rotating joint with respect to an axis and a spherical joint or a cardan joint. Optionally, the connecting rod can be connected to the slide and to the distal support by two rotating joints with respect to an axis, two spherical joints, a rotating joint with respect to an axis and a spherical joint, a rotating joint with respect to an axis and a cardan joint, or a spherical joint and a cardan joint. If one or two rotating joints are used with respect to an axis for said proximal and distal joints, they must have respective joint axes parallel to said axis of rotation.

The electric motor has an output shaft aligned with the spindle axis and is directly coupled thereto, and the spindle is supported on the proximal support in a position that in use is substantially parallel to a longitudinal direction of the proximal part of the orthosis . Thus an extraordinarily compact design is achieved, in which the brackets, the electric motor and the mechanism protrude little from the orthosis laterally compared to the prior art devices.

The electric motor is fixed to an electric motor support, which is coupled to a bearing support in which a bearing that rotatably guides the spindle is installed. The bearing is preferably a bearing, and more preferably an oscillating ball bearing.

The electric motor support and the bearing support are imprisoned against each other by proximal and distal packing plates connected to each other by rods that have connecting portions connected to the proximal and distal packing plates. The proximal and distal packing plates have respective anchors in which an anchor portion of the proximal support is fixed. The aforementioned stems extend parallel to the spindle from the distal packing plate to an end plate. One or more of the stems are slidably inserted in corresponding guide holes of the slide, the said linear guides for it being constituted.

Thus, the slider can move along the spindle guided by the linear guides between the distal packing plate and the end plate. The end of the spindle furthest from the electric motor is not rotatably guided with respect to the proximal support, and it is the nut installed on the slide that keeps the spindle in alignment with the output shaft of the electric motor. The oscillating ball bearing, which is located adjacent to the end of the spindle closest to the electric motor, absorbs any possible misalignment.

The spindle and nut are preferably a spindle and nut assembly of recirculating balls. An activation of the electric motor spins the spindle, it displaces the sliding and the connecting rod pushes the distal support or pulls it to rotate the distal support relative to the proximal support around the support joint. Advantageously, the passage and configuration of the spindle is selected to ensure that the coupling between the nut and the spindle is irreversible, whereby the support joint remains locked when the electric motor is not activated.

In one embodiment, the connecting rod comprises at least a portion made of a slightly elastic material, such as a polymer, which provides a certain elasticity to the mechanism.

The motorization device for active brace of the present invention is designed for a knee brace, where the proximal part of the brace is fixed to the thigh and the distal part of the brace is fixed to the leg. However, one skilled in the art will understand that with slight modifications, the motorization device for active brace of the present invention can be applied alternatively to an elbow brace, where the proximal part of the brace is fixed to the forearm and the distal part of The brace is attached to the arm, or to a hip brace, an ankle brace, etc.

Brief description of the figures

The foregoing and other advantages and features will be more fully understood from the following detailed description of an exemplary embodiment with reference to the accompanying drawings, which should be taken by way of illustration and not limitation, in which: Fig. 1 is a perspective view of an active orthotic motorization device according to an embodiment of the present invention; Fig. 2 is a side elevational view of the motorization device of Fig. 1 in an extended position; Fig. 3 is a side elevation view of the motorization device of Fig. 1 in a bent position; Fig. 4 is a cross-sectional view taken along the plane IV-IV of Fig. 2; Fig. 5 is a partially exploded perspective view of the motorization device of Fig. 1; and Fig. 6 is a cross-sectional view taken on a plane comprising the axis of a spindle and the axis of a linear guide of the motorization device. Detailed description of an embodiment example

Figs. 1 to 6 show a drive device for active brace according to an embodiment of the present invention, which comprises a proximal support 1 intended to be fixed to a proximal part of the brace (not shown) by means of fixing screws 24 and a distal support 2 intended to be fixed to a distal part of the orthosis (not shown) by other fixing screws 25. The proximal and distal supports 1, 2 are connected to each other by a support joint 3 having a rotation axis E1, which, when the drive device is fixed to the orthosis, is aligned with an axis of articulation between said proximal and distal parts of the orthosis. The support joint 3 comprises, for example, a friction bearing 26 disposed between the proximal support 1 and the distal support 2 (Fig. 5).

The drive device comprises a mechanism connected to the proximal and distal supports 1, 2 and driven by an electric motor 4 to rotate the distal support 2 with respect to the proximal support 1 around the axis of rotation E1. For this, the proximal support 1 is fixed to a motor support 13, which has the electric motor 4 fixed by means of screws 20, and to a bearing support 14, in which a bearing 15 is installed, such as a bearing oscillating balls (Fig. 6), which rotatably supports and guides a spindle 5. The motor support 13 and the bearing support 14 are coupled to each other and imprisoned against each other by proximal and distal packing plates 16 , 17 mutually parallel. These proximal and distal packing plates 16, 17 have respective facing holes through which connecting portions 12a of mutually parallel stems 12 are inserted. The connecting portions 12a have threaded end portions of thread in which nuts 21 are secured.

As Fig. 6 best shows, when said nuts 21 are tightened, nuts 21 press on the proximal packing plate 16 and the proximal packing plate 16 presses on projections 13a of the motor support 13, while at the same time projections 12b between the rods 12 and their connecting portions 12a press on the distal packing plate 17 and the distal packing plate 17 presses on projections 14a of the bearing support 14, resulting in the motor support 13 and the support bearing 14 are pressed against each other trapping and immobilizing axially between the two an outer ring of the bearing 15 arranged in a corresponding inner seat of the bearing support 14.

The proximal and distal packing plates 16, 17 have respective anchors 16a, 17a in which an anchoring portion 1 a of the proximal support 1 is fixed by means of screws 22. The stems 12 extend from the distal packing plate 17 to an end plate 18, and are fixed to this end plate 18 by means of screws 23.

The spindle 5 has an outer seat formed in an inner ring of the bearing 15, and a threaded threaded portion in which a nut 27 is attached which axially immobilizes the inner ring of the bearing 15, so that the spindle is supported and guided rotatably in the bearing support 14 which in turn is fixed in the proximal support 1. As Fig. 4 best shows, the spindle 5 is located in a space between the stems 12 in a position parallel to them. The bearing 15 is located near a proximal end of the spindle 5, and the spindle 5 has a free distal end adjacent to the end plate 18 but not supported on the end plate 18.

The electric motor 4 has an output shaft 4a directly coupled to the spindle 5, so that the output shaft 4a of the electric motor 4 is aligned with an axis Eh of the spindle 5 and the spindle 5 is operatively connected to be rotated by the motor electric 4. The spindle 5 is supported on the proximal support 1 in a position such that, in use, that is, when the drive device is fixed to the orthosis, its axis Eh is substantially parallel to a longitudinal direction of the proximal part of the orthosis (not shown).

The mechanism of the drive device further comprises a slide 10 provided with two guide holes 19 (Figs. 4 and 6) in which two of the stems 12 are slidably inserted, which constitute linear guides 11 parallel to the spindle 5 a along which the slide 10 is movable. In the guide holes 19 friction bushings 28 are installed in contact with the corresponding stems 12 (Fig. 6). The slide 10 has a central opening 29 (Figs. 4 and 6) in which a nut 9 is fixed, which in turn is coupled to the spindle 5. The spindle 5 and the nut 9 are preferably a spindle and nut assembly of recirculating balls.

The mechanism of the drive device is completed with a connecting rod 6 having a first end connected to the slide 10 by a proximal joint 7 and a second end connected to the distal support 2 by a distal joint 8, where both proximal and distal joints 7, 8 have respective axes of articulation E2, E3 parallel to the axis of rotation E1 of the support joint 3. On the distal support 2, the distal joint 8 is located in lug 2a projecting in order avoid interference between the connecting rod 6 and the distal support 2, especially when the device adopts bent positions (Fig. 3), and increase the lever arm with respect to the axis of rotation E1 of the support joint 3.

The proximal and distal joints 7, 8 of the connecting rod 6 are formed by forks 30, 31 that support respective articulation pins. The forks 30, 31 are fixed at opposite ends of a rod portion 32. Optionally, this rod portion 32 of the connecting rod 6 is made of an elastic material, obviously with a low degree of elasticity selected to ensure the transmission of forces between the slide and the distal support 2 and at the same time provide a certain elasticity to the mechanism for purposes of ergonomics, consumption reduction and system protection. With this arrangement, an activation of the electric motor 4 causes a rotation of the spindle 5 and it drives the nut 9 and the slide 10 fixed thereto along the linear guides 11 constituted by two of the stems 12. The connecting rod 6 transmits the movements of the slide 10 to the distal support 2, converting the linear movements of the slide 10 into rotational movements of the distal support 2 relative to the proximal support 1 around the axis of rotation E1 of the support joint 3. Figs. 1 and 2 show the drive device in an extended position, while Fig. 3 shows the drive device in a bent position.

The angle between an extended limit position and a bent limit position will depend on the geometry of the mechanism, and can reach and even exceed 90 degrees.

The scope of the present invention is defined in the appended claims.

Claims

1. - Actuation device for active brace comprising a proximal support (1) intended to be fixed to a proximal part of the orthosis and a distal support (2) intended to be fixed to a distal part of the orthosis, said supports being proximal and distal (1, 2) connected to each other by a support joint (3) that has an axis of rotation (E1) aligned in use with an axis of articulation between said proximal and distal parts of the orthosis, an electric motor ( 4) fixed to said proximal support (1), and a mechanism connected to the proximal and distal supports (1, 2) and driven by said electric motor (4) to rotate the distal support (2) with respect to the proximal support (1 ) around said axis of rotation (E1), characterized in that said mechanism comprises:

a spindle (5) rotatably supported on the proximal support (1) and operatively connected to be rotated by said electric motor (4);

a slide (10) movable along at least one linear guide (11) parallel to said spindle (5) and supported on the proximal support (1);

a nut (9) fixed to said slide (10) and coupled to the spindle (5); Y

a connecting rod (6) having a first end connected to the slide (10) by a proximal joint (7) and a second end connected to the distal support (2) by a distal joint (8).

2. - Drive device for active brace according to claim 1, characterized in that said electric motor (4) has an output shaft (4a) aligned with an axis (Eh) of the spindle (5), and the spindle (5) it is supported on the proximal support (1) in a position that in use is substantially parallel to a longitudinal direction of the proximal part of the orthosis.

3. - Active orthosis drive device according to claim 2, characterized in that the electric motor (4) is fixed to a motor support (13) coupled to a bearing support (14) in which a bearing (15) is installed ) which rotatably guides the spindle (5).

4. - Actuating device for active brace according to claim 3, characterized in that said bearing (15) is an oscillating ball bearing.

5. - Drive device for active brace according to claim 3 or 4, characterized in that said motor support (13) and said bearing support (14) are locked against each other by a proximal packing plate (16) and a distal packing plate (17) connected to each other by connecting portions (12a) of rods (12).

6. - Actuation device for active brace according to claim 5, characterized in that said stems (12) extend parallel to the spindle (5) from said distal packing plate (17) to an end plate (18), and at least one of said stems (12) is slidably inserted in a corresponding guide hole (19) of the slide (10) constituting said linear guide (11).

7. - Active orthotic drive device according to claim 6, characterized in that said proximal packing plate (16) and said distal packing plate (17) have anchors (16a, 17a) in which an anchoring portion is fixed (1 a) of the proximal support (1).

8. Drive device for active brace according to claim 1, characterized in that said connecting rod (6) comprises at least a portion made of an elastic material.

9. Drive device for active brace according to claim 1, characterized in that the spindle (5) and said nut (9) are a spindle and nut assembly of recirculating balls.

10. An active orthosis drive device according to claim 1, characterized in that said proximal and distal joints (7, 8) have respective joint axes (E2, E3) parallel to said axis of rotation (E1).

11. Actuation device for active brace according to claim 1, characterized in that said proximal and distal joints (7, 8) comprise at least one rotating joint with respect to an articulation axis (E2, E3) parallel to said axis of rotation ( E1), and / or at least one ball joint and / or at least one cardan joint.