SYSTEM AND METHOD FOR THE REDUCTION OF FORCES ACTING ON AN ARM OF A HUMAN

Abstract

A system having an arrangement for supporting an arm of a user is disclosed. The arrangement has an actuator, which is connected to a shoulder element by a joint chain. The joint chain is designed to extend along the shoulder blade of a shoulder of the user and to introduce vertically acting forces into the shoulder element. Moreover, the joint chain is guided by a flexible structure that extends over the shoulder of the user. By virtue of the deformability of the flexible structure, it is possible to ensure that a lifting of the shoulder, resulting from a lifting of a hand of the user, is not impeded.

Claims

1. A system for reducing forces acting on an arm of a user, comprising: a pelvic element which is configured to be connected to the user's pelvis; a shoulder element which is configured to be connected to the user's shoulder girdle; a spinal element which connects the shoulder element and the pelvic element and is configured to transmit forces exerted on the shoulder element onto the pelvic element; and an arrangement for supporting the arm of the user; wherein the arrangement comprises an actuator which is connected to the shoulder element by a link chain, the link chain being configured to extend along the shoulder blade of a shoulder of the user and to transmit forces acting in the vertical direction to the shoulder element; wherein the link chain is guided by a flexible structure which is configured to extend over the shoulder of the user.

2. The system of claim 1, wherein the link chain is configured to allow a movement of the actuator in a horizontal plane and to prevent a movement of the actuator in the vertical direction, when the user stands upright.

3. The system of claim 2, wherein the joints of the link chain have parallel axes of rotation.

4. The system of claim 3, wherein the parallel axes of rotation extend in the vertical direction when the user stands upright.

5. The system of claim 1, wherein the link chain is a planar swivel link chain.

6. The system of claim 1, wherein the flexible structure comprises one or more elongated and/or flat elements, which are configured to exert a guiding force against a pulling direction onto the link chain.

7. The system of claim 6, wherein the one or more elongated and/or flat elements are bendable or pliable transversely to the direction of pull.

8. The system of claim 1, wherein the flexible structure has elements which are hingedly connected to one another.

9. The system of claim 8, wherein an axis of rotation of the elements which are hingedly connected to one another extends in the vertical direction, when the user stands upright.

10. The system of claim 9, wherein the flexible structure is configured to guide the actuator on a circular path lying in a horizontal plane, when the user is stands upright.

11. The system of claim 10, wherein the pivot of the shoulder joint of the user is in the center of the circular path.

12. The system of claim 8, wherein one of the hingedly connected elements has a curved section which is configured to allow for a vertical displacement of a part of the flexible structure by a vertical offset between the ends of the curved section.

13. The system of claim 12, wherein the curved portion is L- or U-shaped.

14. A method of reducing forces acting on an arm of a user, comprising: attaching the system of claim 1 to the pelvis and the shoulder girdle of the user; and controlling the actuator to reduce the forces acting on the arm of the user; wherein an obstruction to raising the shoulder, resulting from raising a hand of the user, is avoided by the deformability of the flexible structure.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In the following, the invention will be explained in more detail in the detailed description on the basis of exemplary embodiments, wherein reference is made to the drawings in which:

[0017] FIG. 1 is a schematic perspective view of a first system according to the invention;

[0018] FIGS. 2 to 4 are schematic perspective views of a second system according to the invention;

[0019] FIGS. 5 to 7 are schematic perspective views of a third system according to the invention; and

[0020] FIG. 8 shows a flow chart of a method of reducing forces acting on an arm of a user.

[0021] Notably, the shown elements are not necessarily depicted true to scale and in detail, but primarily serve to illustrate the inventive idea.

DESCRIPTION OF THE EMBODIMENTS

[0022] FIG. 1 shows a system 10 for reducing forces acting on an arm of a user. The system 10 comprises a pelvis element 12 for establishing a connection to the pelvis of the user. When the system 10 is put on, the pelvic element 12 is arranged in such a way that it surrounds the user's pelvis and rests on the user's body, thereby enabling a transmission of force between the system 10 and the torso of the user. The pelvic element 12 can also be provided with a pelvic belt 14, or be integrated into a (textile) piece of clothing which encloses the pelvis of the user, to secure the force transmission.

[0023] The system 10 further comprises a shoulder element 16 for establishing a connection to the shoulder girdle of the user. When the system 10 is put on, the pelvic element 16 is arranged in such a way that it surrounds the user's pelvis and rests on the user's body, thereby enabling a transmission of force between the system 10 and the torso of the user. The shoulder element 16 may also be provided with shoulder straps 18 (only exemplary shown for the right shoulder in FIG. 1) or be integrated into a (textile) item of clothing which (partially or completely) encloses the shoulders of the user, to secure the force transmission.

[0024] The shoulder element 16 is connected to the pelvic element 12 by a spinal element 20 which transmits the forces acting on the shoulder element 16 onto the pelvic element 12. The spinal element 20 consists of a plurality of rigid segments 20a which are rotatable relative to one another about two (in the upright state, essentially) horizontal axes of rotation 20b, which allows bending the upper body. To support straightening the upper body, the spinal element 20 can be provided with one or more actuators (not shown) by means of which the relative positions of the segments 20a can be controlled.

[0025] Notably, the embodiment of the spinal element 20 shown in FIG. 1 is only an exemplary possibility and the invention is not limited in this regard. For example, instead of the rigid segments 20a, flexible segments 20a may be used, the rigidity of which is adjusted by means of actuators, and the relative rotation of the segments 20a may be superimposed with a relative displacement of the segments 20a. In addition, the spinal element 20 may comprise more or fewer segments 20a than shown in FIG. 1.

[0026] As shown in FIG. 1, an arrangement 22 for supporting the arm of the user is coupled to the shoulder element 16. The arrangement 22 has an actuator 24 in the form of a pneumatic cylinder which is connected to the shoulder element 16 by a two-link link chain 26. The link chain 26 comprises a first element 26a, wherein a first end of the first element 26a is rotatably coupled to the shoulder element 16 about a vertical axis A, and a second element 26b, wherein a first end of the second element 26b is rotatably coupled to the second end of the first member 26a about a vertical axis B. As shown in FIG. 1, the actuator 24 is rotatably coupled to the second end of the second element 26b about a vertical axis C and causes a rotary movement of an upper arm, forearm, or wrist support 26 about a horizontal axis D.

[0027] The link chain 26 is also guided by means of a flexible structure 30 which spans the user's shoulder (or rests on the user's shoulder). The flexible structure 30 is pliable in the vertical direction and thus transmits (almost) no forces in the vertical direction. As shown in FIG. 1, the flexible structure 30 may comprise two elements 30a, 30b which are articulated to one another (rotatable about an axis of rotation E extending in the vertical direction). If the arm support 26 is designed as an upper arm support and the axes of rotation D and E intersect at the pivot point of the shoulder joint, the upper arm can be supported in its natural movement pattern.

[0028] In order to obstruct raising the shoulder, resulting from raising a hand of the user, as little as possible, one of the articulated elements 30a, 30b has a curved, U-shaped section which is provided for vertical displacement of a part of the flexible structure 30 by a vertical offset between the ends of the curved section. In other words, the second element 30b of the flexible structure 30 is guided between the actuator 24 and the pivot point over the shoulder in the form of two “L” on a non-direct path. This facilitates raising the shoulder, but also allows the actuator 24 to be guided reliably in a circular path around the shoulder pivot point. A similar indirect force flow can also be provided for the first element 30a of the flexible structure 30.

[0029] FIG. 2 shows a further possible embodiment of a system 10 according to the invention, which differs from the system 10 shown in FIG. 1 in that the second element 30b of the flexible structure has an L-shaped section 30b-1, the distal end of which is connected to the link chain 26 by a connecting element 30b-2. As shown in FIG. 3, the material of the second element 30b is chosen such that when the shoulder is raised, the initially flat L-shaped section 30b-1 can be bent away from the initially flat connecting piece 30b-2 in the vertical direction (whereby the L-shaped section is twisted). As illustrated in FIG. 4, the flexible structure 30 gives way when the arm is raised, so that no gap must be provided between the flexible structure 30 and the shoulder (when the arm is lowered) and the system 10 can be designed to be more compact.

[0030] FIGS. 5 to 7 show a further possible embodiment of a system 10 according to the invention, which differs from the system 10 shown in FIGS. 2 to 4 in that the second element 30b is designed as a flexible (textile) band. As shown in FIG. 6, the material of the flexible band is selected such that it expands when the shoulder is raised and thus compensates for the resulting increased height offset. As illustrated in FIG. 7, the raising of the user's shoulder is thus not hindered when the arm is raised, since the flexible band stretches over the shoulder, but does not block the shoulder movement.

[0031] FIG. 8 shows a method of reducing the forces acting on an arm of a user. In step 32, the pelvis element 12 is connected to the pelvis and the shoulder element 16 is connected to the shoulders, and in step 34, the actuator 24 is controlled to reduce the forces acting on the arm of the person. For example, the system 10 can be provided with sensors, from the measured values of which a load condition of the user can be derived and the user can be supported according to his load condition. In particular, the user can be supported in an activity in which the user holds his hands above his head in order to prevent fatigue of the user or to reduce a strain that the user otherwise could not cope with.

LIST OF REFERENCE SIGNS

[0032] 10 system [0033] 12 pelvic element [0034] 14 pelvic belt [0035] 16 shoulder element [0036] 18 shoulder strap [0037] 20 spinal element [0038] 20a segment [0039] 20b axis of rotation [0040] 22 arrangement [0041] 24 actuator [0042] 26 link chain [0043] 26a element (link chain) [0044] 26a element (link chain) [0045] 28 (arm) support [0046] 30 flexible structure [0047] 30a element [0048] 30b element [0049] 30b-1 L-shaped section [0050] 30b-2 connector [0051] 32 process step [0052] 34 process step [0053] A-E rotary axes