GRIPPER WITH BENDABLE FINGERS AND SWITCHING MEANS

Description

[0001] The invention relates to a gripper comprising a gripper base body, at least two gripper fingers, at least one of which is movably mounted on the gripper base body, and at least one drive motor designed to move the at least one gripper finger associated with it and movably mounted on the gripper base body, wherein the at least one gripper finger movably mounted on the gripper base body has a kinematic chain of several successive, mutually adjustable finger links, wherein a proximal finger link in the kinematic chain forms a finger root link and a distal finger link in the kinematic chain forms a fingertip link, and at least one traction means extending longitudinally along the kinematic chain of the respective finger links is provided,which is connected to the fingertip member and which is designed to move the gripper finger movably mounted on the gripper base body from an open position into a closed position of the movably mounted gripper finger and to bend the kinematic chain of the finger members of the movably mounted gripper finger by pulling on the traction means.

[0002] DE 10 2020 207038 A1 describes a gripper comprising a gripper base body, at least two gripper fingers, at least one of which is adjustably mounted on the gripper base body, and a drive motor arranged on the gripper base body, which drive motor is designed to move the at least one gripper finger adjustably mounted on the gripper base body, wherein each gripper finger adjustably mounted on the gripper base body is moved by means of at least one traction means into which a traction force is introduced by the drive motor in order to selectively open or close the gripper by moving the at least one gripper finger adjustably mounted on the gripper base body.

[0003] DE 10 2006 009 559 B3 describes a gripper device in the form of an artificial hand with at least two fingers attached to a frame, of which at least one finger can be transferred from an elongated to a curved finger position by means of an actuator along a movement plane assigned to the finger, wherein the finger is formed in one piece and has a longitudinal extension along which at least one region is provided around which the finger can be bent in the movement plane assigned to it, wherein the at least one region around which the finger can be bent in the movement plane assigned to it is formed in a joint-like manner, that an elongated actuating element with two actuating element ends is provided along the at least one actuator-bendable finger, which transmits tensile and compressive forces,of which one end of the actuator is connected to a fingertip area of ​​the finger opposite the frame and the other end of the actuator is connected in one piece to the actuator.

[0004] The object of the invention is to improve a gripper having at least one bendable gripper finger such that, on the one hand, convex objects can be reliably gripped by bending the at least one bendable gripper finger, and, on the other hand, flat-walled objects can also be reliably gripped without the at least one bendable gripper finger bending. In particular, a purely mechanical solution is to be created that does not require additional active drives.

[0005] The object is achieved by a gripper comprising a gripper base body, at least two gripper fingers, at least one of which is movably mounted on the gripper base body, and at least one drive motor which is designed to move the at least one gripper finger assigned to it and movably mounted on the gripper base body, wherein the at least one gripper finger movably mounted on the gripper base body has a kinematic chain of several successive, mutually adjustable finger links, wherein a proximal finger link in the kinematic chain forms a finger root link and a distal finger link in the kinematic chain forms a fingertip link, and at least one traction means extending longitudinally along the kinematic chain of the respective finger links is provided,which is connected to the fingertip link and which is designed to move the gripper finger, which is movably mounted on the gripper base body, from an open position into a closed position of the movably mounted gripper finger and to bend the kinematic chain of the finger links of the movably mounted gripper finger by pulling on the traction means, wherein the gripper has a switching means which can be switched between a first switching position and a second switching position and which, in the first switching position, completely releases the traction means, so that by pulling on the traction means, the gripper finger, which is movably mounted on the gripper base body, is both pulled into its closed position and the kinematic chain of the finger links of the movably mounted gripper finger is bent, and which, in the second switching position, blocks a traction means section of the traction means running along the kinematic chain of the finger links of the movably mounted gripper finger,so that by pulling on the traction means, the gripper finger movably mounted on the gripper base body is merely pulled into its closed position without the kinematic chain of the finger links of the movably mounted gripper finger being bent.

[0006] The gripper finger in question is movably mounted on the gripper base body, for example, linearly adjustable, i.e., similar to a jaw gripper, or pivotally adjustable, i.e., similar to a pincer gripper. A combined movement of the gripper finger can also be provided.

[0007] The traction means runs from a gripper center, i.e. a central axis of symmetry of the gripper, along which the motor or the motor shaft or spindle shaft of the motor also extends, into the finger base joint at a lower entry point, where it is deflected by approximately 90 degrees, so that the traction means is guided distally upwards along the longitudinal extent of the finger joints of the gripper finger and is fixed to the distal fingertip joint. By pulling on the traction means, the gripper finger can accordingly be pulled into its closed position by the traction means adjusting the finger base joint relative to the gripper base body, wherein in addition the traction means section of the traction means running along the gripper finger is shortened, so that the chain of finger joints of the gripper finger bends.

[0008] According to the invention, the switching means blocks or brakes or clamps this traction means or a separate additional traction means in the gripper finger, so that despite pulling on the traction means, bending of the chain of the finger links of the gripper finger does not occur when the switching means is in its second switching position, but the gripper continues to close as a result of the pulling.

[0009] Essentially, the switching means comprises a button which is activated when the gripper is closed when the movable gripper finger touches the object to be gripped, and a traction means clamping device which blocks or brakes or clamps the traction means or a separate additional traction means in the gripper finger in order to prevent bending of the gripper finger during the closing of the gripper finger when the button is actuated, ie the switching means is in the second switching position.

[0010] The switching means can, in principle, be based on various physical principles. Only the traction mechanism clamping device must operate mechanically insofar as the traction mechanism clamping device is designed to lock or block the traction mechanism. The switching means, in particular the button, and the coupling means can generally operate mechanically, electrically, magnetically, hydraulically, and / or pneumatically, or can consist of a combination of these modes of operation, for example, electromechanically. The button can thus deliver a signal which is transmitted, for example, electrically or electronically to the traction mechanism clamping device. Alternatively or additionally, a force or a torque can be transmitted from the button to the traction mechanism clamping device, for example via a mechanical coupling, such as a coupling rod or a cable.However, the coupling can also transmit magnetically, hydraulically and / or pneumatically if necessary.

[0011] The position of the probe determines whether the gripper finger can bend or remain straight when it is moved into its closed position. The triggering distinction is whether the probe located on the distal phalanx makes contact with the object to be grasped.

[0012] If an object touches the grasping finger at the distal phalanx first, it is either an object that is grasped in a pincer grip, e.g. a small object, or an object that has essentially straight surface parts so that these can be clamped in parallel.

[0013] If, however, the middle phalanges touch the object first, the grasping finger should be curved to best encompass the object. The grasping finger can be curved until the distal phalange or the stylus touches the object, and the grasping finger then fully contacts the object. From this point on, the fingers are essentially only pressed together toward the middle and no longer curved.

[0014] The respective gripper finger therefore has a mechanical trigger, pivoting, sliding, or otherwise mounted, which mechanically transmits contact with the object to a locking element, i.e., the traction mechanism clamping device, and locks the gripper finger against further bending. This trigger can be spring-loaded and is located in an open end position when unfolded.

[0015] The switching means can be a driveless switching means which comprises a mechanical button mounted on the fingertip phalanx, a traction means clamping device and a coupling means which transmits the movement of the mechanical button to the traction means clamping device, so that when the button is actuated, the traction means clamping device is moved into its clamping position in order to assume the second switching position of the switching means.

[0016] In the second switching position of the switching device, the traction device, for example, an actuator cable, is clamped by a lock at the level of the proximal phalanx of the finger, so that the entire cable tensile force is transmitted only to the proximal phalanx. This eliminates the relative tensile force between the phalanxes, which would shorten the gripper finger on the front side. The force on the individual phalanxes is transmitted as a compressive force across the overlapping back surfaces.

[0017] As a possible embodiment, the trigger (i.e., the button) and the lock (i.e., the traction mechanism clamping device) can each be designed as spring-loaded levers that are mechanically connected via a coupling means, such as a traction cable. The coupling means or the traction cable can preferably be guided in the neutral bending fiber of the gripper finger and thus does not experience any change in length when the finger is bent. The clamping can take place in the area of ​​a deflection at the fingertip.

[0018] The traction means clamping device can be formed on the finger root phalanx and can be configured, in its clamping position, to lock the traction means leading through the finger root phalanx in the second switching position of the switching means on the finger root phalanx.

[0019] The traction mechanism clamping device can be designed in the form of a clamping wedge or a brake shoe. The traction mechanism clamping device can comprise a pivoting member or a pivoting jaw, which is pivotally mounted, for example, on the finger base member. The pivotally mounted clamping wedge or brake shoe comprises a clamping surface which, in the second switching position of the switching device, presses against the traction mechanism to clamp the traction mechanism between the clamping wedge or brake shoe and a counter-holding device that is firmly formed on the finger base member.

[0020] The mechanical button can be pivotally mounted on the fingertip phalanx and have a first lever to which a distal end of the coupling means is connected, wherein a proximal end of the coupling means is connected to a second lever which is pivotally mounted on the finger root phalanx and carries the traction means clamping device.

[0021] The coupling means can, for example, be a coupling rod or a coupling cable that connects the first lever to the second lever, so that the second lever executes a movement synchronous with the movement of the first lever. To achieve a certain gear ratio, the first lever and the second lever can have different effective lever lengths. Alternatively, the first lever and the second lever can have identical effective lever lengths.

[0022] The coupling means can be designed as a second traction means which is guided along the kinematic chain of the finger segments of the movably mounted gripper finger in the region of a neutral bending fiber of the gripper finger from the fingertip segment to the finger root segment.

[0023] A second basic embodiment, in contrast to the previously described variant, is based on fixing the length of the back of the gripper finger and thus preventing the back of the gripper finger from stretching to allow it to bend. In this case, a trigger, i.e. the button, presses a lock upon contact with an object, which blocks a separate pulling device, in particular a separate cable or fixing cable. This separate cable runs on the back of the finger, attached to the proximal phalanx of the fingertip, over the middle phalanxes to the distal phalanx of the fingertip, through which it is guided in a 180-degree arc with as little loss as possible when the trigger is not actuated. Since the back of the gripper finger lengthens when it is bent, the separate cable is also pulled on the back by the distal phalanx of the fingertip. When it is stretched, it must be pulled out of the back in the opposite direction, relatively speaking.To achieve this, the loose end of the rope can either be held under tension by a spring or be positively connected to a part of the gripper to ensure it remains taut. Preferably, the second end of the locking rope is also attached to the proximal phalanx and guided along the front of the finger. This rope guide ensures a sufficiently good length, since the front is shortened by the same amount as the back is lengthened when bent. A slight structural angle adjustment of the rope guide to the medial plane of the finger (front and / or back of the finger) can be used as a correction factor to ideally design the ratio of compression to extension, if necessary.

[0024] When the trigger is activated, the clamping takes place in the distal phalanx, preferably essentially on the front side of the finger, by clamping the rope between the lock and the distal phalanx or within a deflection in the phalanx.

[0025] In another slightly modified version, the separate cable is not attached as an endpoint on the back of the proximal phalanx, but is looped there, creating a double cable structure symmetrical to the medial plane of the finger. However, the functionality and principle remain completely unchanged.

[0026] For this purpose, the anchoring means is guided from the finger root joint from an inner side of the gripper finger via a deflection in the fingertip joint to the outer side of the gripper finger and is guided back from the outer side of the gripper finger to the inner side of the gripper finger up to the finger root joint by means of a deflection formed on the finger root joint.

[0027] The tension means clamping device can be formed on the fingertip member and can be configured, in its clamping position, to lock a tensioning means running through the fingertip member in the second switching position of the switching means on the fingertip member.

[0028] By integrating the tensioning device into the fingertip segment, the components of the probe, coupling element, and tensioning device can be fully integrated into the fingertip segment without the coupling element having to be routed through the entire gripper finger across multiple finger segments. The bracing element can provide additional stability to the bendable gripper finger.

[0029] The anchoring means can have a first end section anchored to the finger base link on the convex side of the neutral bending fiber of the kinematic chain of the finger links of the movably mounted gripper finger, a second end section anchored to the finger base link on the concave side of the neutral bending fiber of the kinematic chain of the finger links of the movably mounted gripper finger, and a middle section which runs from the first end section on the finger base link on the concave side of the gripper finger to the fingertip link and from the fingertip link on the concave side of the gripper finger back to the finger base link, which middle section ends at the second end section on the finger base link.

[0030] The central section of the guying means guided through the fingertip member can be released in the first switching position of the switching means for the guying means to pass through the fingertip member and in the second switching position of the switching means the guying means can be fixed in the fingertip member by the traction means clamping device.

[0031] The anchoring means can be guided from the finger root joint from an inner side of the gripper finger via a deflection in the fingertip joint to the outer side of the gripper finger and can be guided back from the outer side of the gripper finger to the inner side of the gripper finger up to the finger root joint by means of a further deflection formed on the finger root joint.

[0032] The gripper finger movably mounted on the gripper base body can be mounted on the gripper base body in a linearly displaceable manner, wherein a linear adjustment of the gripper finger relative to the gripper base body occurs when the pulling means of the movably mounted gripper finger is pulled.

[0033] The gripper finger movably mounted on the gripper base body can be pivotally mounted on the gripper base body, wherein a pivoting adjustment of the gripper finger relative to the gripper base body occurs when the pulling means of the movably mounted gripper finger is pulled.

[0034] A linear movement of the at least one gripper finger or of the multiple gripper fingers, in particular two gripper fingers, can be superimposed with a pivoting adjustment of the gripper finger or fingers. This means that the at least one gripper finger can perform a combined pushing / pivoting movement.

[0035] A substantially linear adjustment in combination with a pivoting movement component can be achieved, for example, by means of a parallelogram joint through which the gripper finger is mounted on the gripper base body.

[0036] An adjustable mounting of the at least one gripper finger, in particular of two gripper fingers, on the gripper base body can be achieved, for example, by means of a parallelogram four-bar linkage. In this case, the parallelogram four-bar linkage comprises two long bars arranged parallel to one another and two short bars arranged parallel to one another, each connected by a pivot joint or a swivel joint. The bars and the swivel joints can be formed as a one-piece molded part. Alternatively, however, the parallelogram four-bar linkage can also be replaced, for example, by a simple swivel joint or swivel joint, or a combination of a swivel joint and a swivel joint.

[0037] The gripper can accordingly have a gripper base body on which each gripper finger is guided via an elastically deformable double joint symmetrically to the gripper center, along the rotational axis of the gripper motor shaft, parallel to the gripper's motor. To grip, the gripper fingers are actively pulled together toward the gripper center by a traction device, such as a cable, and to release, they are passively pulled outward again via separate, antagonistic elastic bands, so-called finger return bands. The traction device is continuously positioned between two gripper fingers. It engages the distal phalanx of the finger, is guided through the middle phalanxes of the finger, and is deflected at the proximal phalanx at an angle of essentially 90° such that it can be wound up by a centrally arranged cable shaft, which is located on the motor shaft or is formed by it.If the gripper finger is bent upon contact with an object to be grasped, an elastic finger extensor band supports the finger's return to the extended position when it is later released.

[0038] Concrete embodiments of the invention are explained in more detail in the following description with reference to the attached figures.

[0039] They show: Fig. 1 a perspective view of an exemplary embodiment of a gripper with a cable actuating means, wherein the gripper fingers are designed as kinematic chains of several links and joints, which can be both closed and bent by means of a cable as a pulling means, Fig. 2 an enlarged perspective partial view of the central cable actuating means according to Fig. 1 , Fig. 3 a schematic representation of a first exemplary embodiment of a switching means in the extended position of the bendable gripper finger with the traction means released, Fig. 4 a schematic representation of the first exemplary embodiment of the switching means according to Fig. 3 in the curved position of the bendable gripper finger with the traction means released, Fig. 5 a schematic representation of the first exemplary embodiment of the switching means according to Fig. 3 in the extended position of the gripper finger with the traction means locked, so that the gripper finger can no longer be bent, Fig. 6 a schematic representation of a concrete variant of a switching means in the extended position of the bendable gripper finger with levers and a coupling means in the neutral bending fiber of the gripper finger with the traction means released, Fig. 7 a schematic representation of the concrete variant of the switching means according to Fig. 6 with the traction means locked, Fig. 8 a schematic representation of a second exemplary embodiment of a switching means in the extended position of the bendable gripper finger with the traction means released, Fig. 9 a schematic representation of the second exemplary embodiment of the switching means according to Fig. 8 in the curved position of the bendable gripper finger with the traction means released, Fig. 10 a schematic representation of the second exemplary embodiment of the switching means according to Fig. 8 in the extended position of the gripper finger with the traction means locked, so that the gripper finger can no longer be bent, Fig. 11 a schematic representation of a concrete variant of a switching means in the extended position of the bendable gripper finger according to Fig. 8 with a rocker arm in a release position, Fig. 12 a schematic representation of the concrete variant of the switching means according to Fig. 11 with the rocker arm in a locking position, in which the additional pulling means, ie the guying means, is locked, and Fig. 13 a schematic representation of a modification of the gripper finger according to Fig. 11 und Fig. 12 , in which the additional pulling means, ie the anchoring means, is guided from an inside of the gripper finger via a deflection in the fingertip link to the outside of the gripper finger and is guided back to the inside of the gripper finger by means of a deflection from the outside of the gripper finger.

[0040] In the Fig. 1 and Fig. 2 an exemplary embodiment of a gripper 1 is shown.

[0041] The gripper 1 has a gripper base body 3 and a pair, ie two gripper fingers 2.1, 2.2, which are each adjustably mounted on the gripper base body 3.

[0042] The two gripper fingers 2.1, 2.2 are each formed with a kinematic chain of several successive, mutually adjustably mounted finger links 7, of which a distal finger link 7.7 in the kinematic chain forms a fingertip link 7c, wherein at least one section of a pulling means 8.1, 8.2 extends longitudinally along the kinematic chain of the respective finger links 7, and the respective pulling means 8.1, 8.2 is connected to the respective fingertip link 7c, so that when a pulling force is introduced into the respective pulling means 8.1, 8.2, the corresponding gripper finger 2.1, 2.2 executes a closing movement and the pulling force can optionally also cause the kinematic chain of the finger links 7 to bend at the same time.

[0043] The multiple consecutive, mutually adjustably mounted finger segments 7 are configured, for example, as a one-piece gripper finger body, wherein two adjacent finger segments 7 can be connected via a film hinge-like web 28, and the multiple webs 28 form a support column of the gripper finger 2.1, 2.2 extending longitudinally within the gripper finger 2.1, 2.2. These webs 28 or the support column form a neutral bending fiber 28a of the respective gripper finger 2.1, 2.2.

[0044] Each finger joint 7, with the exception of the proximal finger joint 7.1, which forms a finger root joint 7a, has a preferably elastic hollow body 21, each of which forms a contact body with which the gripper finger 2.1, 2.2 can contact an object to be grasped. The respective hollow body 21 can be hollow-cylindrical, with the cylinder axes extending parallel.

[0045] Each hollow body 21 has holes 22 ( Fig. 2 ), through which one of the traction means 8.1, 8.2 is threaded. Thus, in an assembled state, the first traction means 8.1, 8.2 each lie within the contour of the respective finger joints 7 or within the contour of the hollow bodies 21. The hollow bodies 21 extend from the neutral fiber 28a, which is defined by the film hinge-like webs 28, in the direction of the object to be gripped, with cross-sectional contours such that the hollow bodies 21 taper towards the object to be gripped. As a result, when the gripper finger 1 is in the extended state, gaps are created between each two adjacent hollow bodies 21, which allow the gripper finger 1 to bend.

[0046] Opposite the hollow body 21, on the other side of the neutral fiber 28a or the webs 28, rear support bodies 23 are formed, which rest on one another when the gripper finger 2.1, 2.2 is extended. For this purpose, the support bodies 23 have flat, pressure-resistant support wall sections arranged on the outside, which abut one another at the end when the gripper finger 2.1, 2.2 is extended. The flat, pressure-resistant support wall sections, together with the film hinge-like webs 28, which form the support column of the gripper finger 2.1, 2.2, form a box frame that is rigid in the opening direction.

[0047] At the respective upper end of each gripper finger 2.1, 2.2, a switching means 24 according to the invention is formed on the respective fingertip member 7.7. The switching means 24 can be designed in different ways and is used in the context of Fig. 3 bis Fig. 12 explained in more detail below.

[0048] An adjustable mounting of the two gripper fingers 2.1, 2.2 on the gripper base body 3 is achieved, for example, by means of a parallelogram four-bar linkage 14, as shown. The parallelogram four-bar linkage 14 comprises two long bars 14.1, 14.2 arranged parallel to one another and two short bars 14.3, 14.4 arranged parallel to one another, which are each connected by a rotary joint or a pivot joint 15.1, 15.2, 15.3, 15.4. In the present embodiment, the bars 14.1, 14.2, 14.3, 14.4 and the pivot joints 15.1, 15.2, 15.3, 15.4 are formed as a single-piece molded part. Alternatively, the parallelogram four-bar linkage 14 can, however, also be replaced, for example, by a simple pivot joint or rotary joint, which, however, is not shown in the embodiment shown.

[0049] The gripper 1 has a drive motor 4 arranged on the gripper base body 3, which is designed to move the at least two gripper fingers 2.1, 2.2, wherein the at least two gripper fingers 2.1, 2.2 are each moved, for example, by means of the traction means 8.1, 8.2. A tensile force can be introduced into the respective traction means 8.1, 8.2 by the drive motor 4 in order to selectively open or close the gripper 1 by moving the at least two gripper fingers 2.1, 2.2, and, if necessary, to perform the curving.

[0050] The gripper 1 has, for example, as shown, a central cable actuating means 16. This cable actuating means 16 is in Fig. 2 shown more clearly in an enlarged partial view.

[0051] The cable actuating means 16 is arranged between the at least two gripper fingers 2.1, 2.2 and is designed to pull the two pulling means 8.1, 8.2 of the two gripper fingers 2.1, 2.2 in the closing direction of the gripper 1 from one side to the central cable actuating means 16 by means of a drive movement of the drive motor 4 arranged on the gripper base body 3.

[0052] The central cable actuating means 16 according to Fig. 1 is even clearer in an enlarged partial view in Fig. 2 The cable actuating means 16 comprises a shaft 17.2, which is arranged centrally between one gripping side of one gripper finger 2.1 and the other gripping side of the other gripper finger 2.2 and extends longitudinally parallel to the gripping sides. The shaft 17.2 is rotatably mounted on the gripper base body 3. The shaft 17.2 has a casing wall 18.2, which is designed to simultaneously wind up one traction means 8.1 of one gripper finger 2.1 and the other traction means 8.2 of the other gripper finger 2.2 when the shaft 17.2 rotates in a winding direction.

[0053] In the case of the present embodiment, the jacket wall 18.2 is waisted.

[0054] The cable pull actuating means 16, i.e. in the case of the present embodiment the shaft 17.2 rotatably mounted on the gripper base body 3, has, for example, a shaft through-bore 29 through which the cable pull 8 is guided in the cable pull direction, in particular is guided through displaceably, wherein the cable pull 8 is designed to actuate the pair of two oppositely arranged gripper fingers 2.1, 2.2 in that one end of the cable pull 8 is connected to one gripper finger 2.1 and the other end of the cable pull 8 is connected to the other gripper finger 2.2. The cable pull 8 thus comprises one pulling means 8.1 of one gripper finger 2.1 and the other pulling means 8.2 of the other gripper finger 2.2. One traction means 8.1 of one gripper finger 2.1 and the other traction means 8.2 of the other gripper finger 2.2 can accordingly be formed by a single cable pull 8. The respective traction means 8.1, 8.2 serve in the second embodiment according to 。 Fig. 1 and Fig. 2 not only to move the two gripper fingers 2.1, 2.2 against each other to close the gripper 1, but also serves to bend the respective gripper finger 2.1, 2.2 by deflecting the respective traction means 8.1, 8.2 by 90 degrees on associated deflection means 30 for each gripper finger 2.1, 2.2, such as deflection rods or deflection rollers, and is guided along the longitudinal extent of the gripper fingers 2.1, 2.2 up to the respective fingertip link 7.7 and is only fixed there.

[0055] Due to the shaft through-hole 29, through which the cable 8 is loosely guided ( Fig. 2 ) and due to the ends of the traction means 8.1, 8.2 fixed to the fingertip links 7.7, the two traction means 8.1, 8.2 are wound up on the casing wall 18.2 of the shaft 17.2 and to this extent the traction means 8.1, 8.2 are shortened and the two gripper fingers 2.1, 2.2 are moved towards each other and thus the gripper 1 is closed, and the gripper fingers 2.1, 2.2 are possibly curved by the traction means 8.1, 8.2 being guided over the deflection means 30 and pulling on the respective fingertip link 7.7 so that the finger links 7 twist and curve the gripper finger 2.1, 2.2.

[0056] The shaft through-bore 29 can be formed with an open-edged recess 31 so that a central section of the cable pull 8 can be suspended in a radial feed direction from outside the jacket wall of the shaft 17.2 into the shaft through-bore 29.

[0057] When the gripper fingers 2.1, 2.2 are fully open, the cable 8 can be provided to run stretched through the shaft through-bore 29, without the cable 8 wrapping around the casing wall 18.2 of the shaft 17.2 in this fully open position of the gripper fingers 2.1, 2.2. In this state, the cable 8 can then automatically realign itself centrally relative to the shaft 17.2 if undesirable side effects, for example due to asymmetrical friction effects, lead to the two gripper fingers 2.1, 2.2 being actuated differently, i.e. the two traction means 8.1, 8.2 being wound up differently.

[0058] One traction means 8.1 can be coupled to one gripper finger 2.1 at a first articulation point 20.1 and the other traction means 8.2 can be coupled to a second articulation point 20.2 ( Fig. 1 ) be coupled to the other gripper finger 2.2 in such a way that the two articulation points 20.1, 20.2 are at the same height, and the pulling means 8.1, 8.2 are connected to the cable actuating means 16 at a different height, which is closer to the gripper base body 3 than the first articulation point 20.1 and the second articulation point 20.2.

[0059] The connection point at which the pulling means 8.1, 8.2 are connected to the cable actuating means 16 at the same height can be formed by a closed shaft through-bore (not shown) or by the open-edged shaft through-bore 29.

[0060] By coupling one traction means 8.1 to a first articulation point 20.1 on one gripper finger 2.1 and the other traction means 8.2 to a second articulation point 20.2 on the other gripper finger 2.2, such that the two articulation points 20.1, 20.2 are at the same height, and the traction means 8.1, 8.2 are connected to the cable actuating means 16 at a lower height, which is closer to the gripper base body 3 than the first articulation point 20.1 and the second articulation point 20.2, it is ensured at first during a commencing closing movement of the gripper 1 that the traction means 8.1, 8.2 are aligned obliquely downwards in the direction of the center of the gripper 1, i.e. in the direction of the cable actuating means 16, so that a traction force caused by the drive motor 4, which is generated by the Traction means 8.1, 8.2 runs at the respective linkage point 20 of the gripper finger 2.1, 2.2 has a force component pointing in the direction of the gripper base body 3. At the same time, this ensures that the traction means 8.1, 8.2 are wound onto the shaft 17.1 or the shaft 17.2, starting from the closed shaft through-bore 19 or starting from the open-edged shaft through-bore 29 of the cable actuating means 16, in a direction away from the gripper base body 3, i.e., in the direction of the free end of the shaft 17.1 or the shaft 17.2.

[0061] The drive motor 4 can be arranged in a receiving pocket 32 ​​formed on the gripper base body 3, such that when the drive motor 4 is received in the receiving pocket 32, the motor shaft of the drive motor 4 extends centrally along an axis of symmetry of the gripper 1 out of the gripper base body 3 in the direction of the gripping gap of the gripper 1.

[0062] Various exemplary embodiments of the switchable switching means 24 according to the invention are shown in Fig. 3 bis Fig. 12 presented and explained in more detail below.

[0063] The switching means 24 is generally between a first switching position ( Fig. 3, Fig. 4 , Fig. 6 , Fig. 8 , Fig. 9 and Fig. 11 ) and a second switching position ( Fig. 5 , Fig. 7 , Fig. 10 and Fig. 12 ) switchable.

[0064] In the first switching position, the pulling means 8.1, 8.2 is completely released from the switching means 24, so that by pulling on the pulling means 8.1, 8.2, the gripper finger 2.1, 2.2 movably mounted on the gripper base body 3 is pulled into its closed position and the kinematic chain of the finger links 7 of the movably mounted gripper finger 2.1, 2.2 is bent.

[0065] In the second switching position, the switching means 24 blocks a traction means section of the traction means 8.1, 8.2 running along the kinematic chain of the finger links 7 of the movably mounted gripper finger 2.1, 2.2, so that by pulling (arrow P) on the traction means 8.1, 8.2, the gripper finger 2.1, 2.2 movably mounted on the gripper base body 3 is only pulled into its closed position, without the kinematic chain of the finger links 7 of the movably mounted gripper finger 2.1, 2.2 being bent.

[0066] The switching means 24 can be a driveless switching means 24 which comprises a mechanical button 5 mounted on the fingertip member 7c, a traction means clamping device 6 and a coupling means 9 transmitting the movement of the mechanical button 5 to the traction means clamping device 6, so that upon actuation of the button 5, the traction means clamping device 6 is moved into its clamping position in order to assume the second switching position of the switching means 24.

[0067] The traction means clamping device 6 is in the case of the illustrated embodiments of the Fig. 3 bis Fig. 7 formed on the finger root phalanx 7a and is accordingly arranged, in its clamping position ( Fig. 5 , Fig. 7 ) to lock the pulling means 8.1, 8.2 leading through the finger root segment 7a in the second switching position of the switching means 24, ie in the present case the button 5, on the finger root segment 7a.

[0068] The mechanical button 5 is in the case of the execution game according to Fig. 6 and Fig. 7 pivotally mounted on the fingertip member 7c and has a first lever 11 to which a distal end of the coupling means 9 is connected and a proximal end of the coupling means 9 is connected to a second lever 12 which is pivotally mounted on the finger root member 7a and carries the traction means clamping device 6.

[0069] The coupling agent 9 is in the case of the embodiments according to Fig. 8 bis Fig. 13 designed as a second traction means 10 or as a guying means 13, which is guided along the kinematic chain of the finger links 7 of the movably mounted gripper finger 2.1, 2.2 in the region of a neutral bending fiber 28a of the gripper finger 2.1, 2.2 from the fingertip link 7c to the finger root link 7a.

[0070] In these embodiments, the traction means clamping device 6 is formed on the fingertip member 7c and is designed to be in its clamping position ( Fig. 10 , Fig. 12 ) to lock the tensioning means 13 running through the fingertip member 7c in the second switching position of the switching means 24 on the fingertip member 7c.

[0071] The anchoring means 13 can have a first end section 13.1 anchored to the finger root link 7a on the convex side of the neutral bending fiber 28a of the kinematic chain of the finger links 7 of the movably mounted gripper finger 2.1, 2.2, a second end section 13.2 anchored to the finger root link 7a on the concave side of the neutral bending fiber 28a of the kinematic chain of the finger links 7 of the movably mounted gripper finger 2.1, 2.2, and a middle section 13.3 guided from the first end section 13.1 on the finger root link 7a on the concave side of the gripper finger 2.1, 2.2 to the fingertip link 7c and from the fingertip link 7c on the concave side of the gripper finger 2.1, 2.2 back to the finger root link 7a, which middle section 13.3 is anchored to the second end section 13.2 ends at the finger root phalanx 7a.

[0072] The central section 13.3 of the anchoring means 13 guided through the fingertip member 7c can be in the first switching position of the switching means 24 ( Fig. 9 , Fig. 11 ) to pass through the tensioning means 13 through the fingertip member 7c and in the second switching position of the switching means 24 ( Fig. 10 , Fig. 12 ) the guying means 13 can be fixed by the traction means clamping device 6 in the fingertip member 7c.

[0073] In the modification according to Fig. 13 the anchoring means 13 is guided from the finger root member 7a from an inner side of the gripper finger 2.1, 2.2 via a first deflection 25.1 in the fingertip member 7c to the outer side of the gripper finger 2.1, 2.2 and is guided back from the outer side of the gripper finger 2.1, 2.2 to the inner side of the gripper finger 2.1, 2.2 up to the finger root member 7a by means of a second deflection 25.2 formed on the finger root member 7a.

Claims

1. Gripper having a gripper main body (3), having at least two gripper fingers (2.1, 2.2), of which at least one is mounted movably on the gripper main body (3), and having at least one drive motor (4) configured for moving the at least one gripper finger (2.1, 2.2) mounted movably on the gripper main body (3), which is assigned thereto, wherein the at least one gripper finger (2.1, 2.2) mounted movably on the gripper main body (3) has a kinematic chain of multiple successive finger members (7) which are mounted so as to be adjustable in relation to one another, wherein a proximal finger member (7.1) in the kinematic chain forms a finger-root member (7a) and a distal finger member (7.7) in the kinematic chain forms a fingertip member (7c), and provision is made of at least one pulling means (8.1, 8.2) which extends longitudinally along the kinematic chain of the respective finger members (7) and is connected to the fingertip member (7c) and is configured for moving the gripper finger (2.1, 2.2) mounted movably on the gripper main body (3) from an open position into a closed position of the movably mounted gripper finger (2.1, 2.2) and for curving the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2) by pulling on the pulling means (8.1, 8.2), characterized in that the gripper (1) has a switching means (24) which is switchable between a first switching position and a second switching position and which, in the first switching position, releases the pulling means (8.1, 8.2) completely, so that pulling on the pulling means (8.1, 8.2) results both in the gripper finger (2.1, 2.2) mounted movably on the gripper main body (3) being pulled into its closed position and in the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2) being curved, and which, in the second switching position, blocks a pulling-means portion of the pulling means (8.1, 8.2) running along the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2), so that pulling on the pulling means (8.1, 8.2) results in the gripper finger (2.1, 2.2) mounted movably on the gripper main body (3) merely being pulled into its closed position without the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2) being curved.

2. Gripper according to Claim 1, characterized in that the switching means (24) is a drive-free switching means (24) comprising a mechanical button (5), which is mounted on the fingertip member (7c), a pulling-means clamping device (6) and a coupling means (9), which transmits the movement of the mechanical button (5) to the pulling-means clamping device (6), so that, when the button (5) is actuated, the pulling-means clamping device (6) is moved into its clamping position in order for the second switching position of the switching means (24) to be assumed.

3. Gripper according to Claim 2, characterized in that the pulling-means clamping device (6) is formed at the finger-root member (7a) and is configured to arrest, in its clamping position, the pulling means (8.1, 8.2) leading through the finger-root member (7a) in the second switching position of the switching means (24) at the finger-root member (7a).

4. Gripper according to Claim 3, characterized in that the mechanical button (5) is mounted pivotably on the fingertip member (7c) and has a first lever (11) to which a distal end of the coupling means (9) is connected, and a proximal end of the coupling means (9) is connected to a second lever (12) which is mounted pivotably on the finger-root member (7a) and supports the pulling-means clamping device (6).

5. Gripper according to Claim 4, characterized in that the coupling means (9) is in the form of a second pulling means (10) which is guided from the fingertip member (7c) to the finger-root member (7a) along the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2) in the region of a neutral bent fibre (28a) of the gripper finger (2.1, 2.2).

6. Gripper according to Claim 2, characterized in that the pulling-means clamping device (6) is formed at the fingertip member (7c) and is configured to arrest, in its clamping position, a bracing means (13) running through the fingertip member (7c) in the second switching position of the switching means (24) at the fingertip member (7c).

7. Gripper according to Claim 6, characterized in that the bracing means (13) has a first end portion (13.1) which is anchored to the finger-root member (7a) on the convex side of the neutral bent fibre (28a) of the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2), has a second end portion (13.2) which is anchored to the finger-root member (7a) on the concave side of the neutral bent fibre (28a) of the kinematic chain of the finger members (7) of the movably mounted gripper finger (2.1, 2.2), and has a middle portion (13.3) which is guided from the first end portion (13.1) at the finger-root member (7a) on the concave side of the gripper finger (2.1, 2.2) as far as the fingertip member (7c) and from the fingertip member (7c) on the concave side of the gripper finger (2.1, 2.2) back to the finger-root member (7a) again, said middle portion ending at the finger-root member (7a) at the second end portion (13.2).

8. Gripper according to Claim 7, characterized in that, in the first switching position of the switching means (24), the middle portion (13.3) of the bracing means (13) guided through the fingertip member (7c) is released for passage of the bracing means (13) through the fingertip member (7c) and, in the second switching position of the switching means (24), the bracing means (13) is fixed in the fingertip member (7c) by the pulling-means clamping device (6).

9. Gripper according to Claim 8, characterized in that the bracing means (13), proceeding from the finger-root member (7a), is guided from an inner side of the gripper finger (2.1, 2.2) to the outer side of the gripper finger (2.1, 2.2) via a diversion (25.1, 25.2) in the fingertip member (7c) and, by means of a further diversion (26) formed at the finger-root member (7a), is guided from the outer side of the gripper finger (2.1, 2.2) back to the inner side of the gripper finger (2.1, 2.2) as far as the finger-root member (7a).

10. Gripper according to one of Claims 1 to 9, characterized in that the gripper finger (2.1, 2.2) mounted movably on the gripper main body (3) is mounted in a linearly displaceable manner on the gripper main body (3) and a linear adjustment of the gripper finger (2.1, 2.2) relative to the gripper main body (3) is realized if the pulling means (8.1, 8.2) of the movably mounted gripper finger (2.1, 2.2) is pulled, and / or the gripper finger (2.1, 2.2) mounted movably on the gripper main body (3) is mounted in a pivotable manner on the gripper main body (3) and a pivoting adjustment of the gripper finger (2.1, 2.2) relative to the gripper main body (3) is realized if the pulling means (8.1, 8.2) of the movably mounted gripper finger (2.1, 2.2) is pulled.