Arm support mechanism

Abstract

Arm support mechanism for supporting a movement of an arm (2) of a user (1) around a shoulder complex (3) of the user, comprising an arm attack (4) which is set up to attack the arm (2) of the user (1), a pool module (5) that is set up to attack a pool of the user (1), a pivot joint (6), a connection on the arm side (7) which is arranged with an end on the arm attack side at the arm attack (4) and which is arranged with an end on the pivot joint side at the pivot joint (6), a pelvic-side connection (8) which is arranged with one pelvic-module-side end on the pelvic module (5) and which is arranged with its opposite end on the pivot joint (6), a drive (9) which is configured to drive the swivel joint (6) about a rotation axis of the swivel joint (6), wherein the pivot joint (6) is arranged to move the arm-side connection (7) and the pelvic-side connection (8) relative to each other about the axis of rotation of the pivot joint (6), wherein the arm attachment (4) is connected to the arm-side connection (7) via a cardan joint or a hinge joint and wherein the pelvic module (5) is connected to the pelvic connection (8) via a cardan joint or a ball joint.

Description

[0001] The invention relates to an arm support mechanism for supporting a movement of a user's arm around a shoulder complex of the user. The arm support mechanism comprises an arm attachment configured to engage the user's arm, a pelvic module configured to engage a user's pelvis, a pivot joint, an arm-side connection between the arm attachment and the pivot joint, and a pelvic-side connection between the pelvic module and the pivot joint. The arm support mechanism further comprises a drive with which the pivot joint can be driven about a pivot joint axis. The drive is configured to move the arm-side connection and the pelvic-side connection relative to one another about the pivot axis of the pivot joint.

[0002] Many everyday work activities require the manual handling of heavy objects or people. Such activities are often associated with considerable strain for those involved. Examples include the manual handling of anesthetized patients in an operating room prep room or general lifting, holding, pushing, pulling, and overhead activities, for example, in logistics and production. To prevent musculoskeletal occupational diseases, it is desirable to provide support for such activities.

[0003] Systems such as patient hoists, sliding boards, and mechanical cable pulley systems are known from the state of the art. Passive exoskeletons for overhead work and lifting tasks have also been proposed in the state of the art, for example, in DE 10 2017 112 436 A1. In this system, a support worker acts purely passively using an elastomer cable pulley via levers.

[0004] DE 10 2016 121 201 A1 describes an orthosis with an abutment element which, when the orthosis is in use, rests against a torso of the wearer of the orthosis, a guide element with an extension direction, an arm support element which, when the orthosis is in use, supports an arm of the wearer, and a joint by means of which the guide element is movable relative to the abutment element, wherein, when the orthosis is in use, the joint is arranged above (cranially) a shoulder of the wearer and the arm support element is displaced relative to the guide element along the extension direction or a length of the guide element is changed in the extension direction when the guide element is moved relative to the abutment element.

[0005] WO 2019 / 081851 A1 describes an exoskeleton with a back structure that can be arranged on the back of a user, an arm structure that can engage the user's arm and a shoulder connection element that connects the back structure to the arm structure, wherein the shoulder connection part has various joints that allow rotation of the arm structure relative to the back structure.

[0006] US 9,889,554 B2, WO 2018 / 083 009 A1, and US 10,383,785 B2 describe other similar arm support devices and exoskeletons.

[0007] Known active exoskeletons are very complex in their basic design and are usually too heavy for practical use. Furthermore, existing solutions are usually designed for specific applications and are not very versatile.

[0008] The object of the present invention is to provide a mechanism which has a low complexity, can be realized with low weight and at the same time allows the support of persons with great strength.

[0009] This object is achieved by the arm support mechanism according to claim 1. The dependent claims specify advantageous developments of the arm support mechanism according to the invention.

[0010] According to the invention, an arm support mechanism is provided for supporting the movement of a user's arm around a shoulder joint or shoulder complex of the user. The human shoulder complex contains a plurality of elements that effectively function as a joint. The terms "shoulder complex" and "shoulder joint" are therefore used synonymously here. The shoulder joint enables rotation of the arm around a plurality of different axes of rotation. The arm support mechanism according to the invention has a pivot joint that is rotatable about a pivot joint axis. The arm support mechanism according to the invention therefore supports the movement of the arm around this pivot joint axis or a pivot axis of the shoulder complex that is coaxial with this pivot joint axis.

[0011] Supporting a movement is understood to mean a force exerted by the arm support mechanism on the user's arm, moving the arm or supporting it in a stationary position. For example, during a lifting activity, the arm support mechanism would exert a force that supports the lifting movement, meaning the user would have to exert less muscle force than without the support. During a holding activity, the arm support mechanism would exert a force that supports holding the arm in the holding position, meaning the user would also have to exert less muscle force to hold it. During a pushing or pulling activity, the arm support mechanism can exert a force that supports the pushing or pulling movement.

[0012] According to the invention, the arm support mechanism has an arm engagement device configured to engage the user's arm, preferably the upper arm or the elbow joint. In principle, engagement with the forearm is also possible, particularly with an optional extension; however, the degree of freedom of the elbow joint would then be unavailable. Advantageously, the arm engagement device can be an arm shell into which the arm can be placed. An arm cuff that can grip the arm is also possible, for example.

[0013] The arm support mechanism also includes a pelvic module configured to engage a user's pelvis or hip. The pelvic module may also be referred to as a hip module. The pelvic module is preferably configured to be fixable to the user's hip or pelvis, particularly preferably in such a way that forces acting on the pelvic module are directed directly to the user's hip, pelvis, and / or legs, but preferably not to the user's spine. The pelvic module may, for example, wrap around the user's waist and bear weight on the user's pelvis. The pelvic module may, for example, be a pelvic shell.

[0014] The arm support mechanism also features the aforementioned pivot joint, which is rotatable about a pivot axis. This axis, hereinafter also referred to as the pivot axis, should be coaxial with an axis about which the user's shoulder complex is rotatable when the arm support mechanism is worn by the user as intended. Preferably, the pivot joint is rotatable about exactly one pivot axis.

[0015] According to the invention, the arm support mechanism further comprises an arm-side connection, which is arranged at one end, hereinafter referred to as the arm-engagement end, on the arm engagement point, and at its opposite end, hereinafter referred to as the pivot-joint end, on the pivot point. The arm-side connection can preferably be configured as a rod.

[0016] Furthermore, the arm support mechanism of the invention has a pelvic-side connection, one of whose ends is arranged on the pelvic module. This end will hereinafter be referred to as the pelvic module-side end. The opposite end of the pelvic connection is arranged on the swivel joint. This end will hereinafter be referred to as the swivel joint-side end. The pelvic-side connection can also advantageously be designed as a rod. To enable adaptation to the size of the user, the pelvic-side connection can advantageously be variable in length and fixable. For this purpose, it can be designed, for example, as a telescopic rod. Such a rod can have a fixing mechanism for setting the length of the telescopic rod.

[0017] According to the invention, the arm support mechanism also has a drive configured to drive the swivel joint about the rotational axis of the swivel joint. A drive is understood here to be an active element, i.e., an active drive. An active drive is, in particular, a drive that can exert a force or torque about the rotational axis without first having to apply a force to the drive, for example, to preload it. Such an active drive can, for example, be an electromechanical drive; alternatively, pneumatic or hydraulic drives are also possible, in which the required pressure is generated by means other than a force on the drive.

[0018] According to the invention, the swivel joint is designed to move the arm-side connection and the pelvic-side connection relative to each other around the rotation axis of the swivel joint. The arm-side connection and the pelvic-side connection can thus rotate relative to each other around the swivel joint axis.

[0019] In a preferred embodiment of the invention, the drive can be a rotary drive arranged on the rotary joint. Such a rotary drive has a rotary drive axis that is advantageously parallel to the rotary joint axis and particularly preferably coaxial with it. It should be noted that it is not necessary for the rotary joint axis and the rotary drive axis to be coaxial with each other, since torque from the drive can also be transmitted to the rotary joint, for example, via a gear or a V-belt. Compared to linear drives, a rotary drive has the advantage of requiring fewer components, thus reducing the weight and complexity of the arm support mechanism.

[0020] In an advantageous embodiment of the invention, the arm support mechanism can comprise a rail, which can preferably be considered part of the pelvic module. This rail can be designed such that the pelvic module-side end of the pelvic connection can be displaced on, in, or at this rail. For this purpose, the pelvic module-side end of the pelvic connection can have a suitable engagement mechanism that engages the rail and holds the pelvic module-side end in contact with the rail while allowing the pelvic module-side end to be displaced along the rail. The shape of the rail can be adapted to the given application. In many cases, however, a straight design of the rail is advantageous, so that the pelvic module-side end of the pelvic connection can be displaced along a straight line.

[0021] The position of the pelvic module end along the rail allows the angle of application of the force acting on the user's arm to be adjusted. The angle between this force and the longitudinal direction of the arm depends on the angle of the arm around the pivot axis, assuming a fixed position of the pelvic module end of the pelvic connection. If, for a given position of the pelvic module end of the pelvic connection, the force acting on the arm is essentially perpendicular to the longitudinal direction of the arm, this force will not act exactly perpendicularly for other arm positions, but will have force components parallel to the arm's longitudinal axis. These force components are then no longer used to lift, hold, pull, or push the arm and can lead to a shift in the arm's attack or to painful shear forces.The displacement of the pelvic module end of the pelvic connection along the rail allows for a substantially vertical application of force to the user's arm at different arm positions.

[0022] For many activities, it is preferable for the splint to extend from dorsal cranial to ventral caudal, i.e., from a rearward position facing the head to a forward position facing the feet, when the arm support mechanism is properly positioned on the user or worn by the user. If the arm-side connection and the pelvic-side connection are designed with a fixed length, this splint extension promotes the vertical application of the force acting on the arm relative to the arm's longitudinal axis.

[0023] In a simple embodiment, the pelvic module-side end of the pelvic-side connection can be fixed to the rail, for example by means of a quick release, a rotary knob, a clamp, a clamping screw, a snap hook, and / or a bolt. In this embodiment, the arm support mechanism can be permanently adjusted for use in a specific arm angular range. This simple solution is sufficient, for example, if the arm support mechanism is used for overhead work where it is not necessary for the arm support mechanism to exert a vertical force on the arm when the arm is not in the overhead area. For many activities, support is only required in small arm angular ranges. In such cases, it may be sufficient to firmly fix the pelvic module-side end to the rail in a suitable position in the manner described.

[0024] Particularly when an activity requires arm support over a larger angular range, it is advantageous if the arm support mechanism also has a force-exerting device with which a force can be exerted on the pelvic module-side end of the pelvic connection, with which force the pelvic module-side end of the pelvic connection can be displaced along the rail. A force-exerting device is generally understood to be any device with which a force can be exerted on the pelvic module-side end. The force-exerting device itself does not need to be an actuator. It can also redirect a force generated elsewhere, for example, by the drive, to the pelvic module-side end.Using such a force application device, the pelvic module-side end of the pelvic-side connection can be moved to a position depending on the current arm angle so that the supporting force acts as perpendicularly as possible on the arm. In this way, the forces acting in the longitudinal direction of the arm described above can be avoided for larger arm angle ranges.

[0025] It may be particularly preferred if the force application device comprises an elastic element arranged parallel to the rail, for example a spring with its spring axis arranged parallel to the rail. Such a spring can be, for example, a compression spring or a tension spring. A suitable choice of a spring constant for this spring can result in the pelvic module-side end of the pelvic-side connection assuming a position for a larger angular range of the arm in which the force acting on the arm is within an acceptable range around the direction perpendicular to the longitudinal direction of the arm, in order to thereby keep the force components occurring in the longitudinal direction of the arm within a sufficiently small range.

[0026] In an advantageous embodiment of the invention, the force-exerting device can comprise a rack and pinion gear, which, on the one hand, has a rack running parallel to the rail and, on the other hand, at least one displacement gear arranged at the end of the pelvic-side connection that engages the rack. Via such a rack and pinion gear, a force can be exerted on the pelvic-side end of the pelvic-side connection, allowing it to be displaced along the longitudinal direction of the rail.

[0027] Optionally, the displacement gear can be driven to rotate by a displacement drive. The displacement drive can preferably be an active drive that can apply a torque to the displacement gear. By appropriately driving the displacement gear, the end of the basin-side connection on the basin module side can be moved to a suitable position along the rail so that the force acting on the arm acts as perpendicularly as possible. The displacement drive can act directly on the displacement gear; however, it is advantageous if a gear transmission is arranged between the displacement drive and the displacement gear, which translates a torque from the displacement drive to the displacement gear. This allows the drive to be made weaker and therefore smaller, and it can also increase the precision of positioning.

[0028] In a further advantageous embodiment of the invention, the arm support mechanism can comprise a toothed belt that, on the one hand, runs around a drive gear that can be driven for rotation by the drive of the rotary joint directly or via a gear transmission, and, on the other hand, runs over an output gear that is identical to the displacement gear or is connected to the displacement gear via a gear transmission. In this way, the drive that also drives the movement around the rotary joint can also be used to drive the displacement gear. This is possible because the position that the pelvic module-side end of the pelvic-side connection should have on the rail depends on the angle of the arm, i.e., the angle of the pelvic-side connection and the arm-side connection around the rotation axis of the rotary joint.There is therefore a clear relationship between this angle and the optimal position of the pelvic module-side end of the pelvic connection on the rail. The drive force of the actuator that drives the swivel joint can therefore be directly used to determine the position of the pelvic module-side end of the pelvic connection on the rail. This further reduces the complexity and weight of the arm support mechanism.

[0029] In an advantageous embodiment, the force-exerting device can also comprise a cable pull system. Such a cable pull system can comprise a cable. The cable can be made of various suitable materials. In general, any structure that essentially only transmits tensile forces can be considered a cable. A wire can also be considered a cable in this sense.

[0030] In this embodiment of the invention, the cable can be attached with one end to one end of the rail and with its other end to the arm-side connection. The cable pull system can then have a roller, referred to below as a rail roller, which is movable along the rail and which is connected to one end of the rail via an elastic element. The rail roller can, for example, slide along the rail on a carriage. This elastic element can, for example, be a spring. If this spring is a tension spring, it can be connected to the end of the rail to which the cable is not attached. If the spring is a compression spring, it can be connected to the end of the rail to which the cable is also attached.

[0031] The rope can then run from the end of the rail to which it is attached to the rail pulley. It can then at least partially encircle the rail pulley and continue behind the rail pulley toward the swivel joint. The fact that the rope at least partially encircles the rail pulley means that the rope touches the rail pulley and does not run straight along the rail pulley. Ultimately, it is important that the rope that runs from the end of the rail where it is attached to the rail pulley runs behind the rail pulley toward the swivel joint.

[0032] The cable then runs at least partially around the rotation axis of the swivel joint to the arm-side connection. For this purpose, the swivel joint can preferably have a pulley coaxial with the swivel joint axis, around which the cable runs.

[0033] Preferably, the cable pulley system also includes a guide pulley around which the cable runs at least partially between the rail pulley and the swivel joint. It is not necessary for the cable to contact this guide pulley in every state of the arm support mechanism. It may be sufficient for the guide pulley to merely define an area in which the cable runs between the rail pulley and the swivel joint.

[0034] In an advantageous embodiment, the arm support mechanism can comprise a support mechanism through which the pelvic-side connection is connected to the pelvic module. In this embodiment, the rail described above is not required. However, it can be optionally provided to enable the support mechanism to be moved.

[0035] The support mechanism can have two or more legs, each of which is arranged at one end on the pelvic module. The ends of the two legs are arranged at a distance from one another on the pelvic module, preferably at positions that have different positions in the horizontal and / or vertical direction, seen when the user is wearing the arm support mechanism as intended and standing. An arrangement in which the end of one leg is arranged dorsally cranial with respect to the end of the other leg, or the end of the other leg is arranged ventrally caudal with respect to the end of one leg is particularly advantageous. When the user is standing, one end can therefore be arranged at the top at the back with respect to the other end, which is arranged at the bottom at the front with respect to one end.

[0036] Advantageously, the legs can each be attached to the pelvic module via a swivel or ball joint. The legs can be positioned with their respective other ends at the pelvic module-side end of the pelvic connection. Preferably, the pelvic module-side end of the pelvic connection and the ends of the two legs meet at a common attachment point.

[0037] In this embodiment of the invention, the legs can be designed such that they have a flexible state in which they are bendable, and a rigid state in which they are rigid against forces acting in the direction of the end of the corresponding leg arranged on the pelvic module and / or acting on the leg with a force component in the direction of the pelvic module-side end of the corresponding leg in a direction not parallel to the leg's longitudinal direction. The legs can then be rigid against compression in the direction of their longitudinal axis, as well as against forces acting laterally on the legs and preferably having a compressive force direction. However, in the rigid state, the legs can also be rigid against forces in all directions.

[0038] The legs can advantageously each be designed such that a first leg is rigid and a second leg is flexible when the arm-side connection to the pelvic-side connection is in a first angular range around the rotation axis of the rotary joint, and such that the first leg is flexible and the second leg is rigid when the arm-side connection to the pelvic-side connection is in a second angular range around the rotation axis of the rotary joint, which is different from the first angular range. Preferably, the first and second angular ranges do not overlap, although this is optional. Preferably, the first and second angular ranges are directly adjacent to one another, so that neither leg is flexible at any angle of the arm-side connection to the pelvic-side connection around the rotary joint axis. Preferably, the first angular range is arranged next to the second angular range in the direction of the first leg.This direction is any direction in which the first leg is arranged next to the second leg.

[0039] The described legs can advantageously have a plurality of blocking elements. These blocking elements can be arranged on a support mechanism cable for each leg. The legs can therefore each have a support mechanism cable and a plurality of blocking elements arranged on it. The blocking elements can then be designed such that they block rotation of adjacent blocking elements about rotation axes that are not parallel to the support mechanism cable when the adjacent blocking elements are in contact with one another and / or are pressed against one another. The blocking elements can also be designed such that they do not block such rotation when they are not in contact with one another and / or are not pressed against one another. In this case, the flexibility of the support mechanism cable can allow the blocking elements to rotate against one another.In this way, the corresponding leg is in its rigid state when the blocking elements are in contact with each other and / or pressed against each other and in its flexible state when the blocking elements are not in contact with each other.

[0040] In the simplest case, the blocking elements can be designed as cubes or cuboids through which the corresponding support mechanism cable runs. However, greater rigidity can be achieved if the blocking elements are designed such that adjacent blocking elements engage with one another when they abut one another on the support mechanism cable. A particularly preferred design of the blocking elements is one in which the blocking elements each have a convex, for example conical, surface in one direction along the corresponding support mechanism cable and a concave, for example conical, surface in the opposite direction along the corresponding support mechanism cable, which surface is parallel to the convex surface. If the blocking elements then abut one another, the convex surface of one blocking element engages with the concave conical surface of the adjacent blocking element.This prevents the two adjacent locking elements from rotating relative to each other. The convex surface can also be referred to as the positive surface, and the concave surface as the negative surface. Advantageously, the locking elements, when in contact with each other, are positively locked in all directions except the one direction of the rope when released (and possibly around the rope's rotation axis as previously described). Instead of a conical design, prisms, pyramids, cuboids, and other shapes are also possible.

[0041] When the leg is in its rigid state, all blocking elements advantageously rest against their respective adjacent blocking elements. It is particularly preferred if the blocking elements are pressed together by a force. In the flexible state, the blocking elements do not have to be adjacent to one another and can be spaced apart. However, when they are adjacent to one another, they are not pressed against one another by a force in the flexible state.

[0042] The pressure with which the blocking elements are pressed against each other to achieve the rigid state of the corresponding leg can advantageously be exerted on the legs by the end of the pool-side connection on the pool module side. For this purpose, it is advantageous if the support mechanism cables of the two legs are each attached at one end to the end of the corresponding leg with which this leg is attached to the pool module, then run through the leg and through the pool-side connection to the drive. In this way, the drive can be used to tension the support mechanism cables. By tensioning the support mechanism cables, the blocking elements are pressed towards the attachment points of the legs on the pool module and thus block, so that the leg transitions to the rigid state.On the other hand, if the tension on the support mechanism cable is released, this force disappears and the locking elements are no longer pressed against each other. The leg transitions to a flexible state.

[0043] Advantageously, the arm support mechanism can comprise a cable pulley arranged coaxially with the drive and driven to rotate by the drive. Those ends of the support mechanism side that are not attached to the pelvic module-side end of the legs can then be attached to the cable pulley. The support mechanism cables of the two legs preferably encircle the rotational axis of the cable pulley at least partially, preferably in opposite directions.

[0044] It should be noted that it is not necessary for the support mechanism cables to change direction at the pulley. It is only important that the support mechanism cables do not run directly in the direction of the pulley's rotational axis in every position of the pulley. Circumferential movement can therefore be defined such that different points of the support mechanism cables are positioned at different angles around the pulley's rotational axis and are arranged on the pulley in such a way that the pulley always releases a section of one support mechanism cable when it pulls on the other.

[0045] In many cases, it is sufficient to pull only a relatively small amount of the support mechanism ropes to place the corresponding legs into their rigid or flexible state. To avoid restricting the freedom of rotation of the arm-side connection around the pivot axis to this relatively small amount, the rope pulley can be connected to the drive via a clutch, such as a slip clutch. This can then allow the corresponding support mechanism rope to be tightened until the corresponding leg transitions to the rigid state, but can then allow further movement of the arm-side connection.

[0046] Another advantageous option for tightening or releasing the support mechanism cables is to attach one end of the support mechanism cables to the end of the corresponding leg with which this leg is attached to the pool module, and to attach the other end to a follower that can be moved along a track of a cam disk. The cam disk can then be rotated about a cam disk rotation axis. In this case, a position of the follower is preferably kept constant in the circumferential direction about the cam disk rotation axis. If the cam disk is now rotated, the follower follows the track. The track can then be designed such that it has sections at different distances from the cam disk rotation axis. If the cam disk is rotated and the follower follows the track, the follower changes its distance from the cam disk rotation axis.If the position of the follower is fixed in the circumferential direction, the follower only changes its position in the radial direction. This pulls on the corresponding support mechanism cable attached to it.

[0047] The cam disc can also have a deflection element, which can be, for example, a roller or a pin. This deflection element can be parallel or coaxial to the cam disc's rotation axis on the side of the cam disc on which the follower is arranged. This allows the corresponding support mechanism cable to extend at least partially around the deflection element, preferably touching it, when the follower is in a suitable position. It should be noted that it is not absolutely necessary for the support mechanism cable to touch the deflection pulley in every position of the cable pulley.

[0048] In an advantageous embodiment of the invention, the arm engagement point can be arranged at the arm-side connection via a joint, for example, a universal joint, a hinge joint, or a ball joint. This prevents torques from being exerted on the arm around an axis that is not the pivot axis.

[0049] Advantageously, the pelvic module can be connected to the pelvic-side connection via a joint, which can be, for example, a universal joint, a hinge joint, or a ball joint. This prevents torques from being exerted on the pelvic module that do not act around the pivot axis.

[0050] The invention will be explained below using a few examples. The features described in the examples can also be implemented independently of the specific example and combined between the examples. The same reference numerals indicate the same or corresponding features.

[0051] It shows Fig. 1 an arm support mechanism according to the invention, Fig. 2A to 2C show an arm support mechanism according to the invention with different positions of the arm, Fig. 3A to 3C show exemplary embodiments of an arm support mechanism according to the invention with a rail, Fig. 4 an arm support mechanism with a cable pull system, Fig. 5A to 5C an arm support mechanism with a support mechanism, Fig. 6A and Fig. 6B a possible design of a leg in the support mechanism, Fig. 7 a mechanism for tensioning a support mechanism rope with a slip clutch and Fig. 8 a mechanism for tensioning a support mechanism cable with a cam disc.

[0052] Fig. 1 shows an example of an arm support mechanism according to the invention for moving an arm 2 of a user 1 around a shoulder complex 3 of the user. The arm support mechanism has an arm engagement 4 configured to engage the user's arm 2. The arm support mechanism also has a pelvic module 5 configured to engage a hip or pelvis of the user 1. Furthermore, the arm support mechanism has a pivot joint 6 and an arm-side connection 7, which is arranged with an arm engagement-side end on the arm engagement 4 and with a pivot joint-side end on the pivot joint 6. The arm support mechanism also has a pelvic-side connection 8, which is arranged with a pelvic module-side end on a pelvic module 5 and with its opposite end on the pivot joint 6.In the example shown, the arm support mechanism also has an active drive 9, which is integrated with the swivel joint here and is designed to drive the swivel joint 6 about a rotation axis of the swivel joint 6. The swivel joint 6 is designed to move the arm-side connection 7 and the pelvis-side connection 8 against each other about the rotation axis of the swivel joint 6. The arm attachment 4 is designed here as an upper arm shell that is concave and into which the arm 2 can be inserted. The arm attachment 4 engages the upper arm of the user 1. The pelvis-side connection 8 is designed as a telescopic rod in the example shown, so that its length is variable. In this way, the distance between the pelvic module 5 and the swivel joint 6 can be adapted to the size of the user 1. In . Fig. In the example shown in Figure 1, the pelvic module 5 also has a back module 10 which, when worn, lies parallel to the back of the user 1.

[0053] The back module 10 is optional but not mandatory. It can be used to evenly distribute forces from the mechanism to the wearer's entire torso. The back module 10 can be secured to the torso with a strap system (for example, like a hiking backpack). The back module 10's design combines flexibility with rigidity to ensure optimal force distribution to the wearer's torso.

[0054] In the example shown, the drive 9 is an active rotary drive whose axis of rotation is parallel or coaxial to the axis of rotation of the rotary joint 6.

[0055] Fig. 2A, Fig. 2B and Fig. 2C show a side view of an arm support mechanism worn by a user 1 according to an example of the invention, in which the pelvic module 5 has a rail 11, which here runs from dorsally cranial to ventral caudal. The pelvic module-side end of the pelvic-side connection 8 is designed to be movable on this rail 11. In Fig. 2A, the arm 2 of the user 1 runs parallel to the body axis. In Fig. 2B, the arm 2 is stretched forward perpendicular to the body axis of the user 1. Fig. 2C shows a state between that of the Fig. 2A and the Fig. 2B. In Fig. In the example shown in Figure 2C, the rail also has an additional spring 12 which exerts a force upwards and backwards.

[0056] In Fig. 2A shows that when the arm support mechanism acts on the arm 2, which is directed downwards parallel to the body axis, the force exerted by the arm attachment 4 is applied to the arm 2 essentially perpendicular to the longitudinal axis of the arm 2. For this purpose, the pelvic module-side end of the pelvic-side connection 8 is positioned at the rear upper end, i.e., at the dorsal cranial end of the splint 11.

[0057] In Fig. In Figure 2B, the pelvic module-side end of the pelvic connection 8 is located at the anterior lower end, i.e., at the ventral caudal end of the rail 11. It can be seen that, in this state, due to the limited length of the rail 11, the force does not act on the arm 2 exactly perpendicular to the longitudinal direction of the arm, but the angle of attack is closer to the vertical than it would be if the pelvic module-side end of the pelvic connection 8 were located at the posterior upper end of the rail 11.

[0058] In the Fig. 2A and Fig. 2B, the pelvic module-side end of the pelvic connection 8 can, in the simplest case, be manually fixable to the rail 11, for example. The rail 11 can be straight or have a two-dimensional, plane, or three-dimensional, spatially curved curve. The fixation of the pelvic module-side end of the pelvic connection 8 can, for example, be achieved by means of a quick-release mechanism and can be adapted to the respective application and the supports. For example, pushing activities can be better supported by selecting the force application point in the rail 11 at the top rear. Lifting activities are better supported by fixing the force application point at the bottom front of the rail 11. For fixation, quick-release fasteners, rotary wheels, clamps, clamping screws, and other means such as bolts and snap hooks can be used.Such fixations allow the arm support mechanism to be prepared for specific activities, such as the activity “pulling / pushing” with the point of application in the back area and for “lifting / carrying” with the point of application of force in the area of ​​the front pelvis or the front hip.

[0059] In Fig. In the example shown in Figure 2C, the arm of user 1 is in an intermediate position between the Fig. 2A and Fig. 2B shown positions. In Fig. In the example shown in Figure 2C, the rail 11 also has a spring 12 that extends from the rear upper end of the rail to the end of the pelvic-side connection 8 on the pelvic module side and exerts a force thereon. The spring force F Feder acts here parallel to the longitudinal direction of the rail 11 to the rear and upwards. If the drive 9 now exerts a torque M Exo , the arm-side connection 7 exerts a resultant force F reson arm 2. This resulting force F res acts essentially perpendicular to the longitudinal direction of arm 2.

[0060] The Fig. The spring used in Fig. 2C can push the point of application of the pelvic module-side end of the pelvic connection 8 downwards and forwards. At the beginning of the movement, when the arm 2 runs parallel to the body axis, the rearward portion of the force vector of the attachment point is relatively large. The point shifts upwards and backwards. During the movement of the pelvic module-side end of the pelvic connection 8 from the top rear to the bottom front in the rail 11, the rearward portion of the force becomes increasingly smaller, and the spring can now push the point further and further forwards until it reaches the very front. The force application angle between arm 2 and arm engagement 4 therefore always remains almost vertical.

[0061] The Fig. The spring 12 shown in Figure 2C is preferably selected with a spring constant such that the tensile forces generated in the spring 12 counteract the longitudinal forces between arm 2 and arm attachment 4 at all times in both direction and magnitude. This solution reduces constraining forces, which increases comfort and user acceptance.

[0062] Fig. 3A, Fig. 3B and Fig. 3C show an exemplary embodiment of an arm support mechanism according to the invention, in which a force application device 13 is provided, with which a force can be applied to the pelvic module-side end of the pelvic connection 8, with which the pelvic module-side end of the pelvic connection 8 can be displaced along the rail 11. The force application device 13 is similar to the Fig. 3A, Fig. 3B and Fig. 3C, the gear mechanism is designed as a rack and pinion gear 13, which has a rack (not shown) running parallel to the rail 11 and a displacement gear 13 arranged at the end of the pool-side connection 8 on the pool module side, which engages with the rack.

[0063] In the Fig. 3A and Fig. 3B, the shift gear 13 is driven to rotate by its own drive. In Fig. 3B, the arm 2 of the user 1 extends vertically downwards parallel to his body axis. In Fig. 3A, arm 2 is angled at approximately 45°. Fig. 3A and Fig. 3B shows the effect of the displacement of the basin module end of the basin-side connection 8 along the rail. In Fig. In the example shown in Figure 3B, the pelvic module-side end of the pelvic-side connection is located at the rear upper end of the rail 11. This exerts a resulting force F on the arm. reswhich acts sufficiently close to the arm 2 in a direction perpendicular to the longitudinal direction of the arm 2. If the user 1 now moves his arm 2 forward, the pelvic module-side end of the pelvic-side connection 8 moves downwards and forwards on the rail 11 by means of the displacement gear 13. This ensures that even when the arm is bent, the resulting force F res acts essentially perpendicular to the longitudinal direction of the arm 2.

[0064] Fig. 3C shows a configuration like the Fig. 3A and Fig. 3B, however, the displacement gear 13 is not driven by its own drive, but by the drive 9, which drives the rotary joint 6. The torque M is transmitted from the drive 9 via a toothed belt 14 to a gear 31, which drives the displacement gear 13 to rotate. Applying the torque M by means of the drive 9 thus simultaneously causes a force on the arm 2 and the appropriate displacement of the pelvic module-side end of the pelvic-side connection 8, so that the resulting force F res as perpendicular as possible to the longitudinal direction of the arm. In Fig. In the example shown in Figure 3C, the toothed belt 14 runs on the drive 9 side around a gear wheel which is coaxial with the axis of rotation of the rotary joint 6 and is driven by the drive 9.

[0065] In Fig. 3A to 3C, a transmission mechanism can be provided that transmits the torque of the drive 9 or the drive provided for the displacement gear 13 to the displacement gear 13 via one or more transmissions. In the example shown, this transmission was realized with a total of five gears. In this way, a much higher speed can be achieved on the last gear 13. This displacement gear 13 is in engagement with the rack, along which the displacement gear 13 is subsequently displaced. The end of the connection 8 on the side of the basin module thus moves in a precisely defined manner along the rail 11 from the top rear to the bottom front during the movement of the drive. Fig. 3C shown V-belts or toothed belts 14, gear stages can also be saved.

[0066] A big advantage of the Fig. 2 and Fig. The advantage of the arm support mechanisms shown in Figure 3 lies in the optimized force application angle on arm 2, whereby at the same time a rigid, multi-joint structure around the shoulder can be dispensed with. The force application angle of the force transmitted by the arm support mechanism on arm 2, in the examples shown on the upper arm, should ideally always be perpendicular to the upper arm. With a fixed joint on the pelvic module 5, the angle is almost perpendicular at the beginning of the movement, where arm 2 hangs downwards parallel to the body axis, but changes slightly as arm 2 moves forward into a sliding movement. This effect becomes even greater during lifting activities up to or above shoulder height, whereby larger portions of the force vector at arm connection 4 act parallel to arm 2.These forces are then no longer used to lift arm 2 and introduce unfavorable forces in the longitudinal direction of the arm, which can lead to a displacement of the connection 4 or to painful shear forces. The mechanisms shown in the examples described here reduce these undesirable forces parallel to the longitudinal direction of the arm.

[0067] Fig. Figure 4 shows another example of an arm support mechanism according to the invention, in which, as in the Fig. 2 and Fig. 3 the basin module-side end of the basin-side connection 8 is movable along a rail 11. The design and course of the rail 11 in the Fig. 2 and Fig. 3 What has been said should also apply to Fig. 4 apply. In Fig. In the example shown in Figure 4, the force application device is designed using a cable pull system. This cable pull system has a cable 15, which is attached with one end to one end of the rail 11, here the rear upper end, and which is attached with another end to the arm-side connection 7. The cable system 15 has a rail roller 15a that is displaceable along the rail 11 and is connected to one end of the rail 11 via an elastic element, for example a spring. If the spring is a tension spring, it is connected here to the end of the rail 11 to which the cable is not attached. In the case of a compression spring, this is connected to the end of the rail 11 to which the cable 15 is also attached. In the example shown, the cable pull system also has an optional guide roller 15b, around which the cable 15 runs at least partially between the rail roller 15a and the swivel joint 6.The cable of the cable pull mechanism then runs from the end of the rail 11 to which the cable 15 is attached, around the rail pulley 15a towards the swivel joint 6, then around the optional guide pulley 15b, then around the swivel joint 6 to the attachment point on the arm-side connection 7. The cable 15 can be guided around the swivel joint 6 and the drive 9, for example via one or more pulleys or cable winches. With a small angle between the pelvic-side and arm-side connections, the wound-up cable 15 is at its maximum length and little cable 15 remains towards the rail 11. The point of force application is therefore forced upwards and rearwards in the rail 11. If the arm is moved upwards (shoulder flexion), the angle between the arm-side connection and the pelvic-side connection increases.As a result, the cable 15 is released and the force application point slides further forward and downward in the rail 11, either voluntarily or due to additional spring force.

[0068] Fig. 5 shows an embodiment of an arm support mechanism according to the invention, which does not require a rail 11. In Fig. In the example shown in Figure 5, the arm support mechanism has a support mechanism 16, via which the pelvic-side connection 8 is connected to the pelvic module 5. For the sake of clarity, Fig. 5 only the arm-side connection 7, the pelvic-side connection 8, the pivot joint 6 with drive 9 and the support mechanism 16 are shown. The support mechanism 16 has two or more legs 16a and 16b, each of which is attached at one end to attachment points 18a and 18b on the pelvic module 5, respectively. The attachment points 18a and 18b are preferably located dorsally cranially and ventrally caudally to each other. For example, the attachment points 18a and 18b can engage points on the pelvic module 5 at which, in the other examples, the Fig. 2 to 4 runs along rail 11.

[0069] The legs 16a and 16b are each designed so that they can switch between a rigid and a flexible state. Fig. 5A, the leg 16a is in a rigid state and the leg 16b is in a flexible state. In Fig. 5B, however, leg 16a is in the flexible state and leg 16b is in the rigid state. Preferably, legs 16a, 16b are designed such that one of the legs 16a, 16b is always rigid, while the other leg 16a, 16b is flexible. It is not impossible for both legs 16a and 16b to be rigid, but both legs 16a and 16b should not be flexible at the same time.

[0070] Whether the legs 16a and 16b are rigid or flexible depends on Fig. 15 depends on the angle between the arm-side connection 7 and the pelvic-side connection 8. In a first angular range around the axis of rotation of the pivot joint 6 between the arm-side connection 7 and the pelvic-side connection 8, the first leg 16a should be rigid and the second leg 16b should be flexible. This example is shown in Fig. 5A. If the arm-side connection 7 to the pelvic-side connection 8 is in a second angular range that is different from the first angular range, the first leg 16a is flexible and the second leg 16b is rigid. This is shown in Fig. 5B. The first angular range is arranged adjacent to the second angular range in the direction of the first leg 16a. This means that when the arm-side connection 7 is further toward the first leg 16a, it is rigid, while when the arm-side connection 7 moves toward the second leg 16b, it becomes rigid.

[0071] In Fig. In the example shown in Figure 5, the legs 16a and 16b each have a plurality of blocking elements 19, which are arranged on a support mechanism cable 17a or 17b for each leg 16a, 16b. The blocking elements 19 are designed to block rotation of adjacent blocking elements 19 about rotation axes that are not parallel to the support mechanism cable 17a or 17b when the adjacent blocking elements 19 are pressed against one another.

[0072] In the simplest case, the blocking elements 19 can be realized as cuboids or cubes, as shown in Fig. 5A and Fig. 5B is indicated. However, a design as in Fig. 6 shown as an example. In Fig. 6, the blocking elements 19 are designed such that adjacent blocking elements 19 engage with each other when they rest against each other on the support mechanism cable 17. In Fig. 6A, the two blocking elements 19 shown do not lie against each other, so that the corresponding leg is flexible. In Fig. In the example shown in Figure 6B, the blocking elements 19 engage with each other so that the corresponding leg is rigid. The blocking elements can, as shown in Fig. 6, each have a convex, for example, conical, surface in one direction along the corresponding support mechanism cable. In the opposite direction along the corresponding support mechanism cable 17, they can have a concave, for example, conical, surface that is parallel to the convex conical surface. In this way, the convex surface can engage the concave surface of the adjacent blocking element 19. For edge-mounted blocking elements 19, it is sufficient if only the surface associated with another blocking element 19 has a corresponding convex or concave surface.

[0073] In Fig. In the example shown in Figure 6A, a resilient element 25 is provided between each two adjacent blocking elements 19, which pushes adjacent blocking elements 19 apart in order to prevent accidental contact of the blocking elements 19.

[0074] In Fig. In the example shown in Figure 6B, the adjacent blocking elements 19 engage with each other, thus achieving a positive fit. In this configuration, all forces and moments can now be transmitted. The support mechanism cables are preferably inextensible or barely extensible.

[0075] The function of the Fig. The configuration shown in Figure 5 is described again below. Fig. In the configuration shown in Figure 5B, the upper arm is stretched downwards. The load thus runs via the leg 16b to the point of application 18b, which is mounted on the pelvic module 5, for example, via a ball joint. The leg 16b is in a rigid state for this purpose. The blocking elements 19 of the leg 16a, however, are in a loose configuration in which they are simply lined up on the support mechanism cable 17a. If the swivel joint 6 rotates due to the action of the motor 9, then from a certain angle between the arm-side connection 7 and the pelvic-side connection 8, the blocking elements of the leg 16b become loose and those of the leg 16a become rigid. This is shown in Fig. 5A. Forces can now no longer be transmitted via leg 16b, but only via leg 16a, so that the effective bearing point shifts to the point of application 18a of leg 16a on the pelvic module 5. The point of application 18a is also preferably mounted on the pelvic module 5, for example, via a ball joint.

[0076] The engagement points 18a and 18b can be rotatably fixed to the basin module 5 and do not have to be movable.

[0077] In the embodiment of the invention that does not require a rail 11 and instead uses a support mechanism 16, the position of the force application point in the pelvic region shifts from one of the legs 16a, 16b to the other of the legs 16a, 16b depending on the angle of the arm-side connection 7 and the pelvic-side connection 8. Shifting the force application point also changes the force vector pointing toward arm 2. This ensures that the force application vector always points as perpendicularly as possible to arm 2.

[0078] In the Fig. 5 and Fig. 6, the legs 16a, 16b are placed in the rigid state by tightening the corresponding support mechanism cable 17a, 17b. Advantageously, this tightening is effected by means of the drive 9. Fig. Figure 7 shows an example of how a support mechanism cable 17 can be tightened by means of the drive 9. For this purpose, the support mechanism cable 17 is wound around a roller 20, which is connected to the drive 9 via a slip clutch. The drive 9 can thus cause a rotation of the roller 20 by a rotation that it performs in order to move the arm-side connection 7 relative to the pelvic-side connection 8, whereby the support mechanism cable 17 is wound up and tightened. The other of the support mechanism cables 17a, 17b would Fig. 7 are wound in opposite directions around the roller 20 or a roller 20 firmly connected to it, so that each rotation of the drive 9 tightens one cable 17a, 17b and releases another cable 17a, 17b. In this way, one of the legs 16a, 16b is always placed in a rigid state, while the other leg 16a, 16b is placed in a flexible state.

[0079] In the Fig. With the slip clutch shown in Figure 7, when the drive 9 rotates, the cable winch 20 rotates and winds up the cable 17, thereby pulling the blocking elements 19 together. Once these are fully contracted, the force pulling on the cable 17 increases dramatically, as the elements can no longer be pulled closer together. This is where the slip clutch engages, preventing further torques beyond a defined limit from being transmitted to the support mechanism cable 17.

[0080] Fig. 8 shows another possibility of tensioning the support mechanism cable 17. In Fig. In the example shown in Figure 8, the corresponding support mechanism cable 17 is attached at one end to a follower 24, which is displaceable on a track 22 of a cam plate 21. A position of the follower 24 in the circumferential direction of the cam plate is preferably fixed, so that the follower 24 can only move in the radial direction, but not in the circumferential direction of the cam plate 21. In the example shown, the track 22 is designed such that it has sections at different distances from a rotational axis of the cam plate 21, which here runs through the center of the cam plate 21. The support mechanism cable then runs from the leg around a deflection pulley 23 to the follower 24.If the cam disc 21 is rotated to a position such that the follower 24 is located in a section of the track that is a large distance from the center point, the support mechanism cable 17 is tightened and the corresponding leg 16a, 16b is in a rigid state. However, if the cam disc 21 is rotated so that the follower 24 is located at a position on the track 22 that is a short distance from the center point, the support mechanism cable 17 is released and the corresponding leg 16a, 16b is in a flexible state.

[0081] In addition to the Fig. In addition to the options shown in Figures 6 to 8, there are also other possibilities for implementing variable stiffness or rigidity of the legs 16a, 16b. For example, fluids under pressure or clamping solutions can be selected.

[0082] In addition to the Fig.In addition to the solutions shown in Figures 5 to 8 with variable stiffness of the legs 16a and 16b, solutions are also conceivable in which the force is transmitted via rigid elements, i.e., elements that do not have variable stiffness, but which can transmit force or not depending on the angle of the pivot joint 6. For example, the leg 16a could slide freely in the pelvic-side connection 8 by means of a prismatic or pivot joint, while the leg 16b and the pelvic-side connection 8 are firmly connected. From a certain angle of the pivot joint 6, in such an example, the leg 16a and the pelvic-side connection 8 can become jammed, preventing the joint freedom of the two elements and allowing force to be transmitted via the point of application 18a. At the same time, also depending on the angle, the bearing point 18b can become detached from its anchorage, whereby no force can be transmitted here.If the motor angle is reduced again, the displacement of the bearing 18b is reconnected at a defined angle, and power transmission is possible again. At the same time, the blocked connection between the leg 16a and the pelvic-side connection 8 can become loose, whereby no more forces are transmitted via the point of application 18a.

[0083] In all figures, the arm-side connection 7 can advantageously be connected to the arm engagement 4 via a joint and / or the pelvic-side connection 8 can be connected to the pelvic module 5 via a joint.

[0084] A particularly advantageous feature is that the arm support mechanism according to the invention requires only one active drive element. Furthermore, the active mechanism can provide force support in two opposite directions. A further advantage is the movable attachment of the mechanism to the pelvic module, which allows the force to be adjusted to suit the application and the user. For example, pushing and pulling can be better supported with a higher starting point than lifting, holding, and supporting above shoulder height. By eliminating additional actuators, further weight can be saved, control complexity reduced, and the wearer's freedom of movement improved.

Claims

[1] Arm support mechanism for supporting a movement of an arm (2) of a user (1) around a shoulder complex (3) of the user, comprising an arm attack (4) which is arranged to attack the arm (2) of the user (1), a pelvic module (5) which is arranged to engage a pelvis of the user (1), a swivel joint (6), an arm-side connection (7) which is arranged with an arm-side end on the arm attack (4) and which is arranged with a swivel joint end on the swivel joint (6), a basin-side connection (8) which is arranged with a basin-module-side end on the basin module (5) and which is arranged with its opposite end on the swivel joint (6), a drive (9) which is arranged to drive the rotary joint (6) about a rotation axis of the rotary joint (6), wherein the rotary joint (6) is arranged to move the arm-side connection (7) and the pelvic-side connection (8) against each other about the axis of rotation of the rotary joint (6), wherein the arm attack (4) is connected to the arm-side connection (7) via a cardan joint or a hinge joint and wherein the basin module (5) is connected to the basin-side connection (8) via a cardan joint or a ball joint. [2] Arm support mechanism according to the preceding claim, wherein the drive is a rotary drive (9) arranged on the rotary joint (6). [3] An arm support mechanism according to claim 2, wherein a rotation axis of the rotary drive (9) is parallel or coaxial to the rotation axis of the rotary joint (6). [4] Arm support mechanism according to one of the preceding claims, wherein the pelvic module has a rail (11) on which the pelvic module-side end of the pelvic-side connection is displaceable. [5] Arm support mechanism according to the preceding claim, wherein the rail (11) extends from dorsal cranial to ventral caudal in a state in which the arm support mechanism is arranged as intended on the user (1). [6] Arm support mechanism according to one of the two preceding claims, wherein the pelvic module-side end of the pelvic-side connection (8) can be fixed to the rail (11), preferably by means of a quick release, a rotary wheel, a clamp, a clamping screw, a snap hook and / or a bolt. [7] Arm support mechanism according to one of claims 4 to 6, further comprising a force exerting device (13) with which a force can be exerted on the pelvic module-side end of the pelvic side connection, with which the pelvic module-side end of the pelvic side connection can be displaced along the rail (11). [8] Arm support mechanism according to the preceding claim, wherein the force exerting device (13) comprises an elastic element (12) arranged parallel to the rail (11), preferably a spring (12) which is arranged with its spring axis parallel to the rail (11). [9] Arm support mechanism according to one of the two preceding claims, wherein the force application device (13) comprises a rack and pinion gear having a rack running parallel to the rail and at least one displacement gear arranged at the pelvic module-side end of the pelvic-side connection, which engages with the rack and pinion. [10] Arm support mechanism according to the preceding claim, wherein the displacement gear (13) is drivable for rotation by a displacement drive, wherein preferably between the displacement drive and the displacement gear (13) a gear transmission is arranged, which effects a transmission of a torque of the displacement drive to the displacement gear (13). [11] Arm support mechanism according to one of the two preceding claims, further comprising a toothed belt (14) which, on the one hand, runs around a drive gear which can be driven to rotate by the drive directly or via a gear transmission, and which, on the other hand, runs over an output gear which is identical to the displacement gear (13) or is connected to the displacement gear via a gear transmission. [12] An arm support mechanism according to any one of claims 7 to 10, wherein the force applying device comprises a cable pulley system, the cable pulley system comprising: a rope (15) which is attached with one end to one end of the rail (11) and which is attached with another end to the arm-side connection, a rail roller (15a) which is displaceable along the rail (11) and which is connected via an elastic element, preferably a spring, to one end of the rail (11), preferably to that end of the rail (11) to which the cable (15) is not attached, wherein the cable (15) runs from the end of the rail (11) to which it is attached to the rail roller (15a), then runs at least partially around the rail roller (15a) in the direction of the swivel joint (6), then runs partially around the axis of rotation of the swivel joint (6) to the arm-side connection (7), wherein the cable pull system preferably also comprises a guide roller (15b) around which the cable (15) runs partially between the rail roller (15a) and the swivel joint (6). [13] Arm support mechanism according to one of the preceding claims, wherein the pelvic-side connection (8) is connected to the pelvic module (5) via a support mechanism (16), wherein the support mechanism has two legs (16a, 16b), each of which is arranged with one end at, when the arm support mechanism is worn by the user (1) as intended and the user (1) is standing, in horizontal and / or vertical directions, different positions on the pelvic module (5) or dorsally cranial and ventral caudal to each other, and which are arranged with their respective other ends at the pelvic-module-side end of the pelvic-side connection (8), wherein the legs (16a, 16b) are each designed such that a first of the legs (16a) is rigid and a second of the legs (16b) is flexible when the arm-side connection (7) to the pelvic-side connection (8) is in a first angular range around the axis of rotation of the rotary joint (6), and that the first leg (16a) is flexible and the second leg (16b) is rigid when the arm-side connection (7) to the pelvic-side connection (8) is in a second angular range, which is different from the first angular range, around the axis of rotation of the rotary joint (6), wherein the first angular range is preferably arranged in the direction of the first leg (16a) next to the second angular range. [14] Arm support mechanism according to the preceding claim, wherein the legs each have a plurality of blocking elements (19), wherein the blocking elements (19) of the legs (16a, 16b) for each leg (16a, 16b) are each arranged on a support mechanism cable (17a, 17b), wherein the blocking elements (19) are designed such that they block rotation of adjacent blocking elements (19) about axes of rotation which are not parallel to the support mechanism cable (17a, 17b) when the adjacent blocking elements (19) are pressed against one another. [15] Arm support mechanism according to the preceding claim, and wherein the blocking elements (19) are designed such that adjacent ones of the blocking elements (19) engage with each other when they abut each other on the support mechanism cable (17a, 17b), wherein preferably the blocking elements (19) each have a convex surface in one direction along the corresponding support mechanism cable (17a, 17b) and have a concave surface in the opposite direction along the corresponding support mechanism cable (17a, 17b) which is parallel to the convex surface. [16] Arm support mechanism according to one of the two preceding claims, wherein the support mechanism cables (17a, 17b) of the two legs (16a, 16b) are each fastened at one end to that end of the corresponding leg (16a, 16b) with which this leg (16a, 16b) is fastened to the pelvic module (5), and are fastened at their other end to a cable pulley (20) which is arranged coaxially to the drive (9) and can be driven to rotate by the drive (9), wherein the support mechanism cables (17a, 17b) of the two legs (16a, 16b) at least partially revolve around an axis of rotation of the cable pulley (20) in the opposite direction. [17] Arm support mechanism according to the preceding claim, wherein the cable pulley (20) is connected to the drive (9) via a slip clutch. [18] Arm support mechanism according to one of claims 14 to 15, wherein the support mechanism cables (17a, 17b) of the two legs (16a, 16b) are each attached at one end to that end of the corresponding leg (16a, 16b) with which this leg (16a, 16b) is attached to the pool module (5), and are each attached at their other end to a follower (24) which is displaceable on a path of a cam disc (21), wherein the cam disc (21) is rotatable about a cam disc rotation axis while preferably a position of the follower (24) in the circumferential direction about the cam disc rotation axis is constant, wherein the track has sections of different distances from the cam disc rotation axis, wherein the cam disc (21) further comprises a deflection element (23) which is parallel or coaxial with the cam disc rotation axis on that side of the cam disc (21) on which the follower (24) is arranged, so that the corresponding support mechanism cable (17a, 17b) runs at least partially around the deflection element, preferably touching it, when the follower (24) is in a suitable position. [19] Arm support mechanism according to one of the preceding claims, wherein the pelvic-side connection (8) and / or the arm-side connection (7) comprises a telescopic rod with which a distance between the pelvic module (5) and the pivot joint (6) can be adjusted.

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