GRIP DEVICE

Description

[0001] The invention relates to a gripping device comprising a chassis, at least one first finger element pivotably mounted on the chassis, at least one drive, and a force transmission element that couples the drive to the first finger element. The gripping device is designed as an orthopedic gripping device and is suitable for use as a prosthetic hand or part of a prosthetic hand.

[0002] The task of a gripping device is to grasp objects and hold them in the gripped position. Different objects require different gripping devices for optimal gripping. The simplest gripping device consists of two rod-like gripping elements that can be moved toward or away from each other around a rigid pivot axis. With such a gripping device, flat objects, for example, are easy to grasp. It becomes problematic when a gripping device is required to grip a large number of objects or to be able to grip a large number of objects with different shapes.Such a challenge arises particularly when using the gripping device as an orthopedic gripping device in a hand prosthesis, since a patient or user of a hand prosthesis is confronted with a multitude of different objects that need to be grasped and held in daily use. Furthermore, a hand prosthesis needs to replace not only the function but also the appearance of a hand. For this purpose, finger elements are mounted on a chassis.

[0003] US 2004 / 00195638 A1 discloses a two-finger gripper in which two gripping devices can be moved from an open position to a closed position, in which the gripping devices are directly opposite each other. An object located between the gripping devices can thus be held. To release the grip, the drive can be reversed.

[0004] WO 03 / 017880 A1 relates to a prosthetic hand in which each individual prosthetic finger, mounted on a chassis, has a separate drive. The drive is located in the respective prosthetic finger. With such a prosthetic hand, it is possible to realize various gripping situations, such as a squirting grip or a lateral grip. Disadvantages include the high control effort required for each individual finger, the complex technology with drives integrated into the fingers, and an increased susceptibility to failure due to the complex design.

[0005] DE 405 871 B1 describes an artificial hand with a chassis or palm on which rotatable fingers and a rotatable thumb are arranged. In the palm, a drive disc rotatable about an axis perpendicular to the palm is connected to the fingers and thumb by means of connections such that rotation of the disc in one direction causes the fingers to open and in the opposite direction causes them to close. The rotation of the disc in one direction is effected by a cord, and the return movement in the opposite direction is effected by a spring inside the disc. Locking teeth are attached to the circumference of the drive disc; these engage with a pawl and hold the drive disc in the position it has reached during rotation by the cord.

[0006] EP 1 971 297 B1 describes a hand prosthesis with a chassis on which several finger prostheses are mounted in an articulated or elastic manner. These finger prostheses can be moved toward one another about at least one pivot axis relative to the chassis via a drive. Power transmission devices are coupled to the finger prostheses on a common drive via a coupling element in such a way that, starting from a rest position, at least two finger prostheses, depending on the direction of rotation of the drive, undergo different adjustment angles in the same direction relative to the chassis. The power transmission devices are coupled to the coupling element in such a way that their drive-side bearings have different dead center positions.

[0007] WO 2007 / 076763 A2 relates to a hand prosthesis comprising a chassis to which at least one finger prosthesis is articulated. The finger prosthesis is connected to the drive via a force transmission device and is movable about at least one pivot axis. The force transmission device between the drive and the finger prosthesis is designed to be rigid in tension and flexible in compression.

[0008] DE 10 2014 007 743 A1 relates to a modular hand element comprising a base element and several finger elements, which can be formed from a group of different finger elements. A thumb element is pivotably mounted on the base element about two axes. A motor for driving the thumb element is arranged within the thumb element. Its output shaft is connected to a gear, the output axis of which is functionally connected to a mounting area of ​​the thumb element via several gears and / or worm gears or other elements.

[0009] US 3,694,021 A describes a mechanical hand with a base plate on which a plurality of fingers are movably arranged. A thumb element is pivotally mounted on the base plate around three axes of rotation. Both the fingers and the thumb element have a plurality of pivot joints. The fingers and thumb element are driven by traction mechanisms that enable independent movement of the individual elements.

[0010] The object of the present invention is to provide a gripping device in which different gripping positions can be achieved in a simplified manner with the least possible effort.

[0011] According to the invention, this is achieved by a gripping device having the features of the main claim. Advantageous embodiments and further developments of the invention are disclosed in the subclaims, the description, and the figures.

[0012] The gripping device comprises a chassis, at least one first finger element pivotably mounted on the chassis, at least one drive, and a force transmission element that couples the drive to the first finger element. The force transmission element pivots the first finger element relative to the chassis about two differently oriented pivot axes. By supporting the finger element about two differently oriented pivot axes and pivoting the first finger element about the two pivot axes by the force transmission element, it is possible to move the first finger element into different positions via the drive using only one force transmission device and to be able to fix this position to a large extent.By arranging the force transmission element at different coupling points on the first finger element, it is possible to achieve different orientations and positions by combining the different rotational movements around the two pivot axes, resulting in improved adaptability to the respective intended use and a greater range of variation. The invention provides that at least one second finger element is pivotally mounted on the chassis and coupled to the drive in such a way that, starting from a rest position, the first and second finger elements traverse different trajectories relative to each other depending on the direction of rotation of the drive.The different trajectories depending on the direction of rotation of the drive make it possible to set different grip positions, for example, a lateral grip and a pinch grip, with the first finger element being rotatable around several pivot axes without the need for an additional drive. Simply by selecting the direction of rotation of the drive, the required grip or the assignment of the finger elements to each other can be achieved with a single switching movement, for example, using electromyographic impulses.

[0013] In addition to the single drive that pivots the finger element around two differently oriented pivot axes relative to the chassis, it is possible to provide additional drives that can be arranged within the finger element. For example, a finger joint can accommodate a drive or consist of a single drive that then serves as an auxiliary drive or as a positioning aid for adjusting the position of the finger joint.

[0014] The pivot axes around which the first finger element can be pivoted can be oriented perpendicular to each other, allowing for a simple design of the finger's movement depending on the drive. If the two axes intersect, the movement of one axis cannot influence the movement of the other. If the axes do not intersect, the rotation around one axis can be used to initiate another movement.

[0015] The first finger element can be mounted on a support so as to be pivotable about one of the pivot axes, with the support being mounted on the chassis so as to be pivotable about the other pivot axis. The support thus represents a first connection between the chassis and the finger element, which ultimately comes into contact with the object to be gripped. The support element enables almost free positioning of one pivot axis due to the possibility of designing the support in almost any way and freely choosing the location and orientation of one pivot axis. The other pivot axis serves to attach the support to the chassis, so that this pivot axis is subject to certain restrictions with regard to its arrangement. The support as an intermediate piece between the chassis and the finger element increases the design options and the orientations of the pivot axes relative to one another.

[0016] A variant of the invention provides that the force transmission element is fastened to the first finger. This fastening can result in a direct fastening of the force transmission element to the finger element. Without the interposition of further force transmission elements, it is possible to achieve a direct coupling between the drive and the finger element. The force transmission element is not coupled to the carrier, but directly to the finger element, so that a pivot axis formed by the carrier on the chassis does not coincide with a fastening point of the force transmission element on the first finger element. In particular, with a pivotable mounting of the force transmission element on the first finger element, the pivot axis about which the force transmission element is mounted on the finger element coincides with the pivot axis with which the carrier element is mounted on the chassis.This allows the distances between the bearing point of the force transmission element on the first finger element and the pivot axis on the chassis to be adjusted, thus altering the forces or torques that can be transmitted via the drive. Likewise, different travel ratios can be set, allowing the gripping device to be adapted to the specific application.

[0017] In a further embodiment, the force transmission element is gimbal-mounted on the first finger element, wherein a rotational degree of freedom about a pivot axis is locked, allowing the finger element to rotate about one of the pivot axes. By locking a rotational degree of freedom, it is possible to apply a torque about one of the pivot axes of the finger element. In a configuration of the gripping device with a finger element mounted on a carrier, the degree of freedom about the carrier pivot axis is preferably locked. The movement of the first finger element about the pivot axis formed on the carrier, the so-called carrier pivot axis, is thus predetermined and effected by the movement of the force transmission element.

[0018] In an alternative embodiment, the force transmission element is connected to the first finger element via a ball joint, whereby the movement of the first finger element, as with a gimbal mount, is controlled or predetermined by the force transmission element. The drive changes the angular position of the force transmission element in the main plane of the drive movement, which runs essentially perpendicular to the axis of rotation of the drive. The force transmission element is pivoted in the main plane and controls the movement of the finger element by changing the angular position due to the rotational movement. The ball joint enables free pivoting of the first finger element.

[0019] The force transmission element can be mounted on a rotatable bearing journal driven by the drive. The bearing journal can rotate on a circular disk or be mounted on an arm driven by the drive. If the force transmission element, which is preferably designed as a rigid component, for example a frame, a support transmitting tensile and compressive forces, or another essentially rigid structure, is pivotally mounted about the bearing journal, the force transmission element performs a circular movement or a circular-segment-shaped movement at the bearing point or moves on a circular or circular-segment-shaped trajectory. This movement preferably takes place in a plane, with the horizontal and vertical movement components of a circular movement in a plane serving to achieve a compound displacement of the finger element about the two pivot axes.

[0020] The power transmission element can be pivotably mounted about an axis perpendicular to the longitudinal extension of the bearing journal, resulting in a cardanic or nearly cardanic mounting of the power transmission element at the bearing point on the bearing journal. This can prevent blockages in the movement.

[0021] If the bearing pin is arranged on an arm, it can be mounted on a frame on a bearing arm that can pivot about an axis, resulting in a superposition of rotational movements that means that the orientation of the force transmission element can be changed in a variety of ways, whereby the pivoting of the finger element about the two pivot axes can be coordinated with each other.

[0022] The arm can be driven on a turntable mounted in the chassis, which allows easy realization of the drive by rotary movements.

[0023] The frame, on which the bearing arm is mounted and on which the arm and bearing pin are also mounted, can be mounted so that it can move in a plane on the chassis. By moving the frame in a plane, additional finger elements can be driven in conjunction with the first finger element. The movement can be controlled via a sliding guide, allowing complex displacement movements of the frame and thus also individual movements of the additional finger elements relative to the chassis.

[0024] A pivot axis of the first finger element may intersect the axis formed by the bearing pin, so that rotation about this axis does not affect the orientation of the first finger element with respect to this one pivot axis.

[0025] The tensile and compressive force-transmitting design of the force transmission element enables precise control of the movement of the first finger element in all directions, allowing a direct coupling between the drive and the finger element without spring elements. In principle, it is possible to incorporate elastic components into the force transmission chain. These components are not primarily intended to return the finger element to its original position, but rather to protect the mechanical system or to achieve a flexible movement behavior of the finger element when subjected to external forces, which is particularly pleasant for the user in orthopedic gripping devices. If the first finger element strikes an object, the interposition of elastic buffer elements can reduce the direct transmission of force to the drive, the motor, and, if applicable, the support on a forearm stump.

[0026] The at least one second finger element can be coupled to the drive via a bracket mounted on the chassis so that it can be folded about an axis. The bracket allows for almost any arrangement of a power transmission device with which the bracket can be coupled to the drive. This makes it particularly easy to make adjustments, so that pivot angles and power transmissions can be changed by differently positioning the first power transmission device between the drive and the bracket. The first power transmission device, which connects the drive to the bracket, can be mounted on an eccentrically moved bearing element coupled to the drive, so that when the drive is activated, the bracket can be pivoted or folded about the axis in one direction or the other together with the first finger element.

[0027] The bracket can be coupled to the at least one second finger element via a second force transmission device. The second force transmission device can be fixable at different locations on the bracket so that, depending on the positioning of the second force transmission device on the bracket, different adjustment angles relative to the chassis can be achieved with the same pivoting angle of the bracket relative to the chassis. This allows the movements of the second finger elements relative to one another and of the second finger elements relative to the first finger element to be changed and adapted to the respective gripping situation or the respective intended use. Both the first force transmission device and the second force transmission device can be designed to transmit tensile force and compressive force. This eliminates the need for return elements; instead, a forced movement is brought about by changing the direction of rotation of the drive.

[0028] A further development of the invention provides for the bracket to be elastically deformable, which allows the finger elements to be flexible in response to external forces, i.e., forces transmitted from the finger element to the chassis. It is also possible to generate changes in the adjustment angle or the respective trajectory through the elastic deformability.

[0029] As an alternative to driving the second finger elements via the bracket, it is possible to use the frame as a coupling element for the second force transmission device, so that the displacement of the frame relative to the chassis is transmitted via the second force transmission device to the second finger element coupled via the second force transmission device.

[0030] Exemplary embodiments of the invention are explained in more detail below with reference to the accompanying figures. They show: Figure 1- a plan view of an open gripping device in a first position; Figure 2 - a side view of the gripping device in the lateral grip; Figure 3 - a view according to Figure 1 in a partially closed position; Figure 4 - a view according to Figure 3 in a closed position in a pinch grip; Figure 5 - a view of the position according to Figure 2 in bottom view; Figure 6 - a side view of the position according to Figure 4 ; Figure 7 - a schematic representation of the gripping device in a bottom view; Figure 8 - a schematic representation according to Figure 7 in a side view; Figure 9 - a variant of the drive of the second finger elements in bottom view; Figure 10 - a variant of the drive of the second finger elements in plan view; and Figure 11 - a side view of the Figure 10 .

[0031] Figure 1shows a bottom view of a gripping device 1 in the form of a prosthetic hand with a chassis 2 on which a dovetail recess is formed in order to mechanically connect the chassis 2 to proximal prosthetic components, for example a forearm shaft. A first finger element 3, which is designed as a thumb, is pivotally mounted on the chassis 2. Furthermore, four second finger elements 321, 322, 331, 332 are pivotally mounted on the chassis 2. The two second finger elements 321, 322, designed as index fingers and middle fingers, are each mounted on the chassis 2 via a pivot axis 3210, 3220; the second finger elements 331, 332, designed as ring fingers and little fingers, are each likewise pivotally mounted on the chassis 2 via a pivot axis 3310, 3320 (not shown).Furthermore, a motor drive is attached to the chassis 2, which is arranged on the back or the side of the gripping device 1 corresponding to the back of the hand. The drive, which will be explained later, drives a force transmission element 5, which in turn is coupled to the first finger element 3, so that when the force transmission element 5 moves, the finger element 3 is displaced relative to the chassis 2 and thus also relative to the other finger elements 321, 322, 331, 332. The chassis 2 forms a frame to which the finger elements are attached and in which the drive and the other components are mounted. The chassis is essentially modeled on the shape of a palm of the hand and has a main plane that essentially corresponds to the palm of the hand and is oriented parallel to the plane of the page in the figure.

[0032] The power transmission element 5 is designed as a rigid component and is H-shaped. On the drive side, the power transmission element 5 is mounted about two axes 591, 592 on a bearing journal 9, which represents an eccentric point of the turntable 40. The bearing arm 10 is pivotally attached to a frame 11, which is slidably mounted on the chassis 2, about an axis 101. The bearing arm 10 is attached to the turntable 40 and pivotally mounted about the axis 81. Another bearing journal is formed around the axis 81, which forms another eccentric point on the turntable 40. The frame 11, the turntable 40, the bearing arm 10, and the arm 8 are arranged essentially parallel to one another and parallel to the main plane of the chassis 2.The axis 101 of the pivot arm 10 runs parallel to the pivot axis 81 of the arm 8 and parallel to the axis 592, which is formed by the longitudinal extension of the journal 9 and about which the force transmission element 5 is rotatably mounted. The force transmission element 5 is mounted via a sleeve on which journals are arranged, forming a second axis 591, which is oriented essentially orthogonal to the axis 592, which is formed by the longitudinal extension of the bearing journal 9. The two axes 591, 592 intersect. The second axis 591 runs essentially parallel to the plane in which the arm 8, the bearing arm 10, or the turntable 40 are arranged.

[0033] The end of the force transmission element 5 opposite the drive side is pivotally mounted on the first finger element 3 about a first axis 531, which is oriented substantially parallel to the second axis 591 on the bearing journal 9. The first finger element 3 is mounted on the chassis 2 via a support 6. The support 6 is pivotally mounted on the chassis 2 about a pivot axis 32 and forms a second pivot axis 31 at the end facing away from the chassis 2, which is oriented differently than the chassis-side pivot axis 32. The first finger element 3 can thus be displaced relative to the chassis 2 about two pivot axes 31, 32, which are formed by the support 6. The chassis-side pivot axis 32 is oriented such that the first finger element 3 can be pivoted or extended outwards, so that the first finger element 3 is pivoted in the direction of a plane in which the frame 11 or the turntable 40 is located.When the gripping device is configured as a prosthetic hand, this plane corresponds to the palm of the hand. When pivoted or flexed in the other direction, the first finger element 3 moves about the chassis-side pivot axis 32 toward the opposite second finger elements 331, 332, i.e., essentially perpendicular to the plane of the page according to FIG. Figure 1 .

[0034] In the illustrated embodiment, the finger-side pivot axis 31 does not intersect the chassis-side pivot axis 32 and runs in a plane that is oriented orthogonally to the chassis-side pivot axis 32. This makes it possible for the first finger element 3 to be pivoted about the finger-side pivot axis 31, wherein the pivoting movement can occur in the direction of the index finger 321 or away from it. To make this possible with a rigid force transmission element 5, the force transmission element 5 is mounted on the finger element 3 about a second axis 532 in addition to the first axis 531, resulting in a cardanic bearing that is locked in one rotational degree of freedom in order to effect a force transmission for pivoting the finger element about the finger-side pivot axis 31 when the force transmission element 5 is moved by the drive.

[0035] If the arm 8 is rotated counterclockwise about a rotation axis 401 of the turntable 40 and the bearing arm 10 is pivoted clockwise about the axis 101, the force transmission element 5 moves to the right. The axis 591 pivots clockwise about the bearing pin 9, and the first finger element 3 is displaced about the chassis-side pivot axis 32 in the direction of the palm of the hand or toward the opposite second finger element 332, which corresponds to the little finger in a prosthetic hand. A reverse movement and a displacement of the axis 591 in the direction of the chassis-side pivot axis 32, i.e., to the left, would cause a pivoting about the chassis-side pivot axis 32 and thus an opening of the gripping device 1 or a movement of the first finger element 31 outward.At the same time, due to the change in the orientation of the bearing pin 9 relative to the finger-side pivot axis 31, a pivoting movement of the finger element 3 about the finger-side pivot axis 31 is brought about. Since the first finger element 3 does not run parallel or coaxially to the finger-side pivot axis 31, but protrudes from it, i.e. the longitudinal extent of the first finger element does not coincide with the pivot axis 31, the orientation of the first finger element 3 to the chassis 2 and the distance and angular position to the other second finger elements 321, 322, 331, 332 also change. Starting from the maximum open or extended position, which is shown in the . Figure 1is approximately reached, depending on the direction of rotation of the drive and the pivoting movement of the bearing pin 9 in conjunction with the pivoting of the arm 8 or the bearing arm 10, different trajectories and movement courses of the respective finger elements 3, 321, 322, 331, 332 relative to one another result.

[0036] Figure 2 shows a side view from the direction of the proximal connection point, i.e., in the area of ​​the dovetail guide for attaching the gripping device 1 to another component, for example, a forearm shaft. On the side of the chassis 2 facing away from the power transmission element 5, the drive 4 in the form of an electric motor can be seen. Via the drive 4, the turntable 40 and thus the bearing arm 10 and arm 8 as well as the frame 11 are displaced within the chassis 2, if necessary with the interposition of a gear. Figure 2The arrangement of the frame 11, layered in parallel planes, with the turntable 8 arranged therein and the bearing arm 10 and the arm 8 arranged above it, can be seen. The axis 591 runs essentially parallel to the plane of the frame 11, whereas the second axis 592 is oriented perpendicular to this plane and corresponds to the longitudinal extent of the bearing pin 9. The chassis-side pivot axis 32 also runs essentially parallel to the plane of the frame 11, so that the carrier 6, with its two perpendicularly oriented, spaced-apart pivot axes 32, 31, can be pivoted into a plane parallel to the plane of the frame 11 or perpendicular thereto about the chassis-side pivot axis 32. The finger element 3 can additionally be pivoted about the finger-side pivot axis 31. Figure 2The orientation of the first axis 531 can also be seen, which in this exemplary embodiment extends parallel to the axis 591 through the two pins perpendicular to the bearing pin 9. To create a cardanic bearing, the axis 531 is cardanically mounted via a bearing body pivotable about the second axis 532. Figure 2 shows the position of the gripping device in a so-called lateral grip, in which the first finger element 3 is placed laterally against the nearest second finger element 321, which is required, for example, for gripping flat elements such as a sheet or the like. Such a position of the finger elements 3, 321 is achieved by moving the drive 4 such that, starting from the open, extended position according to Figure 1the second finger elements 321, 322 are pivoted upwards from the plane formed by the frame 11 or the main plane of the chassis 2 more quickly than the first finger element 3, which is also pivoted forwards, i.e. around the finger-side pivot axis 31.

[0037] Figure 3 shows a position of the finger elements 3, 321, 322, 331, 332, in which the bearing pin 9, starting from the initial position according to Figure 1was pivoted clockwise. Likewise, the rotation axis 81 of the arm 8 was displaced clockwise around the rotation axis 401 of the turntable 40. The bearing arm 10 is moved downward by the displacement of the rotation axis 81. As a result, the frame 11 is also pivoted clockwise around the axis 101 by the bearing and thus moved downward. As a result, the second finger elements 321, 322, 331, 332 are pivoted about their respective pivot axes, so that the gripping device is increasingly closed when the finger elements 3, 321, 322, 331, 332 are flexed.The first finger element 3 was rotated counterclockwise about the finger-side pivot axis 31, while at the same time pivoting took place about the chassis-side pivot axis 32 in the direction of the other second finger elements 321, 322, 331, 332, so that the axis 531 was rotated counterclockwise and, upon further displacement of the bearing pin 9, the first finger element 3 is brought together with the two second finger elements 321, 322. This further movement and the combined position is shown in the . Figure 4 shown.

[0038] The frame 11 is displaced further downwards and the bearing arm 10 is rotated further clockwise around the axis 101, as is the arm 8, so that the bearing pin 9 is displaced further to the right along a path of movement. The distal ends of the finger elements 3, 321 are touching each other; a further displacement of the bearing pin 9 would lead to an increased contact force between the finger elements 3, 321. The Figure 4 The position shown is the so-called pointed grip, in which the tips of the curved finger elements 3, 321, 322 lie against each other.

[0039] In contrast, the alternative end position, in which the bearing pin 9 is turned counterclockwise to the maximum, is in the Figure 5 The so-called lateral grip guides the first finger element 3 laterally to the second finger element 321, the frame 11 is in comparison with the Figure 4further downwards so that the second finger elements 321, 322, 331, 332 are pivoted further out of the main plane of the chassis 2 into a closed position before contact with the first finger element 3 is reached.

[0040] The pointed handle according to Figure 4 is in the Figure 6 shown in a side view, all finger elements 3, 321,322, 331, 332 are pivoted maximally upwards from the plane of the frame 11 or the main surface or palm of the hand into a flexed position.

[0041] Figure 7 shows a schematic representation of the gripping device in the position according to Figure 1 in the solid lines, in the dashed representation in the position according to Figure 5. The bearing, the drive and the assignment of the second finger elements are not shown here. Starting from the maximum open position of the gripping device, the force transmission element 5 is pivoted counterclockwise along a circular path, so that the bearing pin 9 moves downwards and to the right on the circular path. Due to the movement to the right, the first finger element 3 pivots about the chassis-side pivot axis 32 and performs a closing movement; due to the movement downwards, the pivoting about the finger-side pivot axis 31 takes place, whereby an adduction of the first finger element 3 occurs, i.e. a pulling towards the chassis 2 and the second finger elements. The end position, as shown in the dashed illustration, corresponds to the Figure 5shown position of the lateral handle. When pivoted by the drive 4 in the opposite direction, i.e. clockwise, the bearing pin 9 is displaced upwards and to the right, whereby in addition to the closing movement about the chassis-side pivot axis 32, an abduction movement about the finger-side pivot axis 31 occurs, so that in the respective end position the pointed handle is positioned, as shown in the Figure 4 is shown.

[0042] In the Figure 8 The movement of the first finger element 3 relative to the chassis 2 is shown in a side view. When pivoting from the starting position according to Figure 7The movement component away from the chassis-side pivot axis 32 causes a flexion of the first finger element 3 relative to the chassis 2, while an opposite movement causes an extension, i.e. an increase in the angle between the first finger element 3 on the side of the force transmission element 5 relative to the chassis 2. The flexed position is shown in the dashed line, the extended position in the solid line. The finger-side first axis 531 of the force transmission element 5 lies above the second axis 591, about which the force transmission element 5 is pivotally mounted on the bearing pin 9. By shifting the axis 591 in the main plane, a shift of the axis 531 and thus a pivoting of the support 6 and the finger element 3 arranged thereon about the chassis-side pivot axis 32 is possible.

[0043] Figure 9shows a schematic representation of the movement of the second finger elements 321, 322, 331, 332 by the displacement of the frame 11 relative to the chassis 2. The drive moves the frame 11 in a curved guide rail 111 in which a pin 22 of the chassis is guided. Furthermore, a pivot arm 21 is mounted on the chassis 2 and is pivotally mounted with the frame 11 in the region of the attachment point of the gripping device. If the frame 11 is displaced downwards by the drive 4, starting from the starting position shown in solid lines, the frame 11 moves along the guide rail 111 and around the pivot arm 21 into the position shown in dashed lines. The second finger elements 321, 322, 331, 332 pivot about the respective pivot axes 3210, 3220, 3310, 3320, since the frame 11 is coupled to the second finger elements 321, 322, 331, 332 via second force transmission elements 51.

[0044] An alternative way of driving the second finger elements is in the Figure 10Instead of a frame 11, a bracket 211 is mounted on the chassis 2 about a pivot axis 2110. The bracket 211 can be moved from the illustrated extended position of the second finger elements 321, 322, 331, 332 into a flexed position about the axis 2110. The second finger elements 321, 322, 331, 332 are then in a closed position, and the bracket 211 is pivoted away from the pivot axes 3210, 3220, 3310, 3320, as shown in the dashed illustration. In order to execute this pivoting movement of the bracket 211, the bracket 211 is connected to the drive 4 via a first power transmission device 51. The first power transmission device 51 is mounted on an eccentrically mounted bearing element 290 or a pin coupled to the drive 4. In the illustrated embodiment, the power transmission device 51 is designed as a loop that is wrapped around the bearing element 290.The first force transmission device 51 can slide along the bearing element 290, so that during the circular movement of the bearing element 290, upon rotation from a position maximally close to the axis 2110 to a position maximally distant from the axis 2110 along a circular path, a length compensation occurs between the two sections of the force transmission device. The force transmission device 51 can be pivotably and optionally displaceably mounted on the bracket 211. The bracket 211 can be made of an elastic material, for example, an elastic plastic material.

[0045] Figure 11shows the actuation of the second finger elements by means of the bracket 211 in a side view. In the starting position, the second finger elements are extended, i.e., the angle α between the main plane of the chassis 2 and the side of the second finger element facing the power transmission device 51 is at a maximum. In the dashed representation, the included angle α is at a minimum, i.e., the second finger elements are almost perpendicular to the main plane of the chassis 2. The bearing element 290 is displaced at a maximum distance from the axis 2110 of the bracket 211, so that the pivoting of the respective second finger element about the respective pivot axis on the chassis takes place via the displacement of the bearing element 290 and the pivoting of the bracket 211 and the associated pivoting of the second power transmission device, which couple the bracket 211 to the respective second finger elements.

Claims

1. A gripping device for a hand prosthesis having - a chassis (2), - at least one first finger element (3) mounted pivotably on the chassis (2), - at least one a rotationl movement producing drive (4), and - a force transmission element (5) coupling the drive (4) to the first finger element (3), whereas the force transmission element (5) is adapted to pivot the first finger element (3) relative to the chassis (2) about two differently oriented pivot axes (31, 32), wherein at least one second finger element (321, 322, 323, 324) is mounted pivotably on the chassis (2) and is adapted to pivot upon activation of the drive (4) and is coupled to the drive (4) in such a way that, proceeding from a rest position, and depending on the direction of rotation of the drive (4), the first and second finger elements (3; 321, 322, 323, 324) travel on different trajectories relative to each other.

2. The gripping device as claimed in claim 1, characterized in that the pivot axes (31, 32) are oriented perpendicularly with respect to each other and / or do not intersect each other.

3. The gripping device as claimed in claim 1 or 2, characterized in that the first finger element (3) is mounted on a support (6) pivotably about one of the pivot axes (31), and the support (6) is mounted pivotably on the chassis (2) about the other pivot axis (32).

4. The gripping device as claimed in claim 3, characterized in that the force transmission element (5) is secured on the first finger element (3).

5. The gripping device as claimed in claim 4, characterized in that the force transmission element (5) is mounted pivotably on the first finger element (3).

6. The gripping device as claimed in claim 5, characterized in that the force transmission element (5) is mounted on the first finger element (3) by a cardan joint or by a ball-and-socket joint, and the movement of the first finger element (3) about one of the pivot axes (31) is controlled by the force transmission element (5).

7. The gripping device as claimed in one of the preceding claims, characterized in that the force transmission element (5) is mounted pivotably about a bearing pin (9) on a rotatable arm (8) driven by the drive (4).

8. The gripping device as claimed in claim 7, characterized in that the force transmission element (5) is mounted pivotably about an axis (591) perpendicular to the longitudinal extent of the bearing pin (9).

9. The gripping device as claimed in claim 7, characterized in that the arm (8) is mounted at a frame (11) on a bearing arm (10) pivotable about an axis (101).

10. The gripping device as claimed in claim 7 or 9, characterized in that the arm (8) is driven by a rotary disk (40) mounted in the chassis (2).

11. The gripping device as claimed in claim 9 or 10, characterized in that the frame (11) is mounted displaceably in one plane on the chassis (2).

12. The gripping device as claimed in one of claims 7 through 11, characterized in that a pivot axis (31) of the first finger element (3) intersects the axis (592) formed by the bearing pin (9).

13. The gripping device as claimed in one of the preceding claims, characterized in that the force transmission element (5) is configured to transmit tensile force and compressive force.

14. The gripping device as claimed in claim 1, characterized in that at least one second finger element (321, 322, 323, 324) is coupled to the drive (4) via a bracket (211) mounted on the chassis (2) so as to be foldable about an axis (2110).

15. The gripping device as claimed in claim 14, characterized in that the bracket (211) is connected to the drive (4) via a first force transmission device (51).

16. The gripping device as claimed in claim 15, characterized in that the first force transmission device (51) is mounted on an eccentrically moved bearing element (290) that is coupled to the drive (4).

17. The gripping device as claimed in one of claims 14 through 16, characterized in that the bracket (211) is coupled to the at least one second finger element (321, 322, 323, 324) via a second force transmission device (52).

18. The gripping device as claimed in one of claims 14 through 17, characterized in that the bracket (211) is designed to be elastically deformable.

19. The orthopedic gripping device as claimed in claim 1 in conjunction with claim 9, 10 or 11, characterized in that the frame (11) is coupled to the second finger element (321, 322).