ROBOT GRIPPER

Abstract

The invention relates to a robot gripper comprising: a main gripper body that has a connection flange designed to secure the rotational gripper to a tool flange of a robotic arm; also a base element that is mounted on said main gripper body such that it can rotate about a first rotational axis by means of a first rotational joint able to be adjusted automatically by a first drive motor; and a first gripper finger mounted such that it can rotate about a second rotational axis aligned parallel to the first rotational axis, relative to the base element, by means of a second rotational joint which can be adjusted automatically by a second drive motor; as well as at least one additional gripper finger, said second rotational joint being designed to adjust the first gripper finger individually, using the second drive motor, independently of said at least one additional gripper finger.

Claims

1. Robot gripper, comprising a main gripper body (12) that has a connecting flange (13), which is designed to secure the rotational gripper (11) to a tool flange (8) of a robot arm (2); furthermore, comprising a base link (14) that is mounted on the main gripper body (12) in a manner allowing rotation about a first axis of rotation (D1) by means of a first pivot joint (15.1), which is automatically adjustable by a first drive motor (A1); as well as comprising a first gripper finger (16.1), which is mounted in a manner allowing rotation with respect to the base link (14) about a second axis of rotation (D2), which is aligned parallel to the first axis of rotation (D1), by means of a second pivot joint (15.2), which is automatically adjustable by a second drive motor (A2); and comprising at least one additional gripper finger (16.2, 16.3), characterized in that the second pivot joint (15.2) is designed for adjusting the first gripper finger (16.1) individually by means of the second drive motor (A2), independently of the at least one additional gripper finger (16.2, 16.3).

2-15. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0054] Specific embodiments of the invention are explained in greater detail in the following description with reference to the accompanying figures. Specific features of these exemplary embodiments may represent universal features of the invention independently of the actual context, in which they are mentioned, and, as the case may be, can also be considered individually or in combination.

[0055] FIG. 1 is a perspective view of an industrial robot in the manner of a six-axis articulated arm robot;

[0056] FIG. 2 is a perspective view of a robot in the manner of a lightweight robot;

[0057] FIG. 3 is a perspective view of a robot in the manner of a SCARA robot;

[0058] FIG. 4 is a perspective view of an inventive robot gripper, which is attached to a tool flange of a robot arm, according to FIG. 2;

[0059] FIG. 5a is a sectional view of the robot gripper, according to FIG. 4, shown alone;

[0060] FIG. 5b is a perspective, sectional view of an embodiment of the robot gripper with an exemplary drive assembly;

[0061] FIG. 6 is a bottom view of the gripper fingers of the robot gripper, according to FIG. 4, with its three axes of rotation;

[0062] FIG. 7 is a bottom view of the gripper fingers of the robot gripper, according to FIG. 4, with indicated, exemplary paths of motion of the first gripper finger;

[0063] FIG. 8 is a perspective view of the robot gripper, according to FIG. 4, holding an exemplary cube from the outside;

[0064] FIG. 9 is a perspective view of the robot gripper, according to FIG. 4, holding an exemplary frame from the inside;

[0065] FIG. 10 is a bottom view of the gripper fingers of the robot gripper, according to FIG. 4, with an alternative first gripper finger, which exhibits a triangular cross section and which holds a part exhibiting a circular-sector shape in cross section;

[0066] FIG. 11 is a bottom view of the gripper fingers of the robot gripper, according to FIG. 4, holding an exemplary pin;

[0067] FIG. 12a is a perspective view of the robot gripper, according to FIG. 4, holding an exemplary thin pin with an end face of the first gripper finger;

[0068] FIG. 12b is a perspective view of the robot gripper, according to FIG. 4, holding an exemplary thicker pin with a broad side of the first gripper finger;

[0069] FIG. 13 is a perspective view of the robot gripper, according to FIG. 4, with a non-driven first gripper finger;

[0070] FIG. 14a is a perspective view of the robot gripper, according to FIG. 4, with an L-shaped first gripper finger in a wide position;

[0071] FIG. 14b is a perspective view of the robot gripper, according to FIG. 4, with an L-shaped first gripper finger in a narrow position;

[0072] FIG. 15a is in schematic form a sectional view of the robot gripper with gripper fingers, projecting laterally beyond the main gripper body, in a first configuration for grasping very small objects, in particular, in the vicinity of a boundary wall;

[0073] FIG. 15b is in schematic form a sectional view of the robot gripper with gripper fingers, projecting beyond the main gripper body on diametrically opposite sides, in a second configuration for grasping objects that are larger than the main gripper body itself; and

[0074] FIG. 16 is a perspective view of the robot gripper, according to FIG. 4, with adjustable outer shell wall sections.

DETAILED DESCRIPTION

[0075] FIG. 1 shows a robot 1, which comprises a robot arm 2, and a robot controller 10. In the case of the present exemplary embodiment the robot arm 2 comprises a plurality of sequentially arranged links L1 to L7, which are connected to each other by means of joints J1 to J6 in such a way that said links can rotate.

[0076] The robot controller 10 of the robot 1 is designed or configured to execute a robot program, by means of which the joints J1 to J6 of the robot arm 2 can be automated according to the robot program or automatically adjusted in a manual operation or rotationally moved. For this purpose the robot controller 10 is connected to controllable electric motors M1 to M6, which are designed to adjust the joints J1 to J6 of the robot 1.

[0077] In the case of the present exemplary embodiment of an industrial robot 1a the links L1 to L7 are a frame 3 and a rotating table 4, which is mounted in a manner allowing rotation relative to the frame 3 about a vertically extending axis A1. Other links of the robot arm 2 are a link arm 5, a boom arm 6 and a preferably multi-axis robot hand 7 with an attachment device, which is designed as a tool flange 8 and is provided for the purpose of securing a robot gripper 11 of the present invention. The link arm 5 is mounted on the rotating table 4 at the lower end, i.e., on the joint J2 of the link arm 5, said end being also referred to as a link arm bearing head, in such a way that said link arm can pivot about a preferably horizontal axis of rotation A2.

[0078] At the upper end of the link arm 5, the link arm 5 is mounted on the first joint J3 such that said link arm in turn can pivot about an axis A3 of the boom arm 6, said axis being also preferably horizontal. Said boom arm carries on its end the robot hand 7 with its preferably three axes of rotation A4, A5, A6. The joints J1 to J6 can be driven in each case by one of the electric motors M1 to M6 in a program controlled manner by means of the robot controller 10. Generally for this purpose a transmission can be provided between each of the links L1 to L7 and the respectively associated electric motors M1 to M6.

[0079] FIG. 2 shows a robot 1 in an exemplary embodiment as a so-called lightweight robot 1b, which comprises a robot arm 2 and a robot controller 10b. In the case of the present exemplary embodiment the robot arm 2 comprises eight sequentially arranged links L1-L8, which are rotatably connected to each other by means of joints J1-J7. In the case of the exemplary embodiment shown in FIG. 2, the link L8 is formed as a tool flange for the purpose of securing a robot gripper 11 of the present invention.

[0080] FIG. 3 shows a robot 1 in an exemplary embodiment as a so-called SCARA robot 1c, which comprises a robot arm 2 and a robot controller 10c. In the case of the present exemplary embodiment the robot arm 2 comprises five sequentially arranged links L1-L5, which are rotatably connected to each other by means of joints J1-J4. In the case of the exemplary embodiment shown in FIG. 3, the link L5 is formed as a tool flange for the purpose of securing a robot gripper 11 of the present invention.

[0081] FIGS. 4 to 15 show exemplary embodiments of the robot gripper 11 of the invention in schematic form.

[0082] The robot gripper 11 has a main gripper body 12, which comprises a connecting flange 13, which is designed for the purpose of securing the rotational gripper 11 to the tool flange 8 of the robot arm 2. In addition, the robot gripper 11 has a base link 14, which is mounted on the main gripper body 12 in a manner allowing rotation about a first axis of rotation D1 by means of a first pivot joint 15.1, which is automatically adjustable by a first drive motor A1. Furthermore, the robot gripper 11 comprises a first gripper finger 16.1, which is mounted in a manner allowing rotation with respect to the base link 14 about a second axis of rotation D2, which is aligned parallel to the first axis of rotation D1, by means of a second pivot joint 15.2, which is automatically adjustable by a second drive motor A2. In addition, the robot gripper 11 has at least one further gripper finger 16.2, 16.3, where in this case the second pivot joint 15.2 is designed to adjust the first gripper finger 16.1 individually by means of the second drive motor A2, independently of the at least one further gripper finger 16.2, 16.3.

[0083] In the case of the present exemplary embodiment the robot gripper 11 has a finger support 17, to which the first gripper finger 16.1 is attached. The finger support 17 is mounted on an intermediary link 18 of the robot gripper 11 in a manner allowing rotation about a third axis of rotation D3, which is aligned parallel to both the first axis of rotation D1 and the second axis of rotation D2, by means of a third pivot joint 15.3 which is automatically adjustable by a third drive motor A3. The intermediary link 18 in turn is mounted on the base link 14 in a manner allowing rotation about the second axis of rotation D2 by means of the second pivot joint 15.2.

[0084] In such an embodiment the links of the robot gripper 11, which links are formed by the main gripper body 12, the base link 14, the intermediary link 18 and the finger support 17, form a kinematic chain of links, which can be adjusted in a manner allowing rotation, as indicated, in particular, in FIG. 6, by means of the first pivot joint 15.1, the second pivot joint 15.2 and the third pivot joint 15.3. In this respect the first gripper finger 16.1 can be rotationally adjusted with respect to the main gripper body 12 in a total of three degrees of freedom. In this case the three axes of rotation D1, D2 and D3 of the first pivot joint 15.1, the second pivot joint 15.2 and the third pivot joint 15.3 are aligned parallel to each other. As a result, it is possible for the first gripper finger 16.1, mounted on the finger support 17, to occupy not only any position and, in so doing, have any orientation in the plane of the second end face of the main gripper body 12, but also to reach any position even on any path of motion. This applies, in particular, when the distances between the first axis of rotation D1 and the second axis of rotation D2 or between the second axis of rotation D2 and the third axis of rotation D3 are the same. If the length ratios are different, then in that case the areas in the center of the robot gripper 11 cannot possibly be approached.

[0085] Consequently the first gripper finger 16.1 may have a universal freedom of motion relative to the second gripper finger 16.2 and the third gripper finger 16.3 in the plane, i.e., may generate any type of gripper movement. Thus, for example, two opposite gripper fingers may perform a linear movement towards one another and away from each other, but may also perform a pliers-like or scissors-like movement towards each other. That means that one gripper finger 16.1 can be moved towards the other gripper finger 16.2 and/or 16.3 or away from it on a circular path, as shown in FIG. 7.

[0086] However, the one gripper finger 16.1 can also be moved towards the other gripper finger 16.2 and/or 16.3 or away from it on any other path, as also shown in FIG. 7. In this case the one gripper finger 16.1 can vary its orientation in any number of ways during these movements.

[0087] The base link 14 has a rotationally symmetrical outer shell wall, on which the base link 14 is rotatably mounted completely inside the outer contour of the main gripper body 12. The intermediary link 18 of the robot gripper 11 has a rotationally symmetrical outer shell wall, on which the intermediary link 18 is rotatably mounted completely inside the outer contour of the base link 14. The finger support 17 of the robot gripper 11 has a rotationally symmetrical outer shell wall, on which the finger support 17 is rotatably mounted completely inside the outer contour of the intermediary link 18.

[0088] As can be seen, in particular, in FIG. 5, the base link 14 has a profile height H1 that points in the direction of the first axis of rotation D1 and that is at most as large as the profile height H0 of the main gripper body 12 that points in the direction of the first axis of rotation D1. In this case the intermediary link 18 of the robot gripper 11 also has a profile height H2 that points in the direction of the second axis of rotation D2 and that is at most as large as the profile height H1 of the base link 14 that points in the direction of the second axis of rotation D2. The finger support 17 of the robot gripper 11 has a profile height H3 that points in the direction of the third axis of rotation D3 and that is at most as large as the profile height H2 of the intermediary link 18 that points in the direction of the third axis of rotation D3.

[0089] In a specific design variant the first pivot joint 15.1 comprises a first rolling bearing 19.1, which surrounds the base link 14 and which comprises an inner ring, an inner ring raceway for rolling bodies, an outer ring and an outer ring raceway, wherein the inner ring is attached to the rotationally symmetrical outer shell wall of the base link 14. As an alternative, the inner ring raceway can be formed on the rotationally symmetrical outer shell wall of the base link 14.

[0090] In this case the second pivot joint 15.2 comprises a second rolling bearing 19.2, which surrounds the intermediary link 18 and which comprises an inner ring, an inner ring raceway for rolling bodies, an outer ring and an outer ring raceway, wherein the inner ring is attached to the rotationally symmetrical outer shell wall of the intermediary link 18. As an alternative, the inner ring raceway may be formed on the rotationally symmetrical outer shell wall of the intermediary link 18.

[0091] In addition, the third pivot joint 15.3 comprises a third rolling bearing 19.3, which surrounds the finger support 17 and which comprises an inner ring, an inner ring raceway for rolling bodies, an outer ring and an outer ring raceway, wherein the inner ring is attached to the rotationally symmetrical outer shell wall of the finger support 17. As an alternative, the inner ring raceway may be formed on the rotationally symmetrical outer shell wall of the finger support 17. With respect to the bearings, it may hold that the inside ones are located in the outside ones. However, it may be that the segments of the inner supports protrude further and, in so doing, penetrate into the region of the outer supports. In this case the segments may be, for example, segments of the drive, which are located, as shown, for example, in FIG. 5, above the bearing arrangements, but below the base body. This is the case, for example, if the drives have been moved into the main gripper body.

[0092] The first gripper finger 16.1 may have a non-circular cross sectional contour in a cross section that extends perpendicular to its longitudinal extent.

[0093] In the case of the exemplary embodiments that are shown, the second gripper finger 16.2 and the third gripper finger 16.3 are rigidly attached to the main gripper body 12.

[0094] The second gripper finger 16.2 is arranged to be mounted on the main gripper body in such a way that the outer contour of the second gripper finger 16.2 lies completely inside an enveloping cylindrical surface HZ, which is defined by the outer periphery of the main gripper body 12. Similarly in the case of the exemplary embodiments that are shown, even the third gripper finger 16.3 is arranged to be mounted on the main gripper body 12 in such a way that the outer contour of the third gripper finger 16.3 lies, as shown, in particular, in FIG. 4, completely inside an enveloping cylindrical surface HZ, which is defined by the outer periphery of the main gripper body 12.

[0095] One exemplary drive assembly of the robot gripper 11, which may be combined with the type of mounting described above, but can also be combined together with a different type of mounting, is shown in FIG. 5b. In the case of the present exemplary embodiment the robot gripper has a total of three motors 23.1, 23.2, 23.3. All three motors 23.1, 23.2, 23.3 are located inside the base link 14. Thus, the first motor 23.1 is mounted on the output side and moves with the base link 14. The first motor 23.1 moves the first axis of rotation D1. The first motor 23.1 carries on its motor shaft a spur gear 24.1, which engages in a gear ring that exhibits internal teeth and that is secured to the main gripper body 12. The second motor 23.2 moves the second axis of rotation D2. If the first motor 23.1 is moved, then the second motor 23.2 moves accordingly. For this purpose a first toothed drive pulley 24.2 is mounted on the motor shaft of the second motor 23.2. A first timing belt 25.1 runs on the first toothed drive pulley 24.2. The first timing belt 25.1 also runs on a first toothed output pulley 26.2, which is attached to the intermediary link 18. When the second motor 23.2 rotates, the intermediary link 18 is also rotated. The third motor 23.3 carries on its motor shaft a second toothed drive pulley 24.3. A second timing belt 25.2 runs on the second toothed drive pulley 24.2. The second timing belt 25.2 also runs on a second toothed output pulley 26.3, which is coupled by means of a third timing belt 25.3 to the finger support 17. Therefore, the third motor 23.3 is moved on the drive side in front of the axis of rotation D2 and bridges the axis of rotation D2 and exhibits an additional coupling due to the third timing belt 25.3. When the third motor 23.3 rotates, the finger support 17 is also rotated and, thus, the first gripper finger 16.1 is consequently rotated.

[0096] When the second gripper finger 16.2 and the third gripper finger 16.3, as designed in the exemplary embodiment, are rigidly attached to the main gripper body 12, then the second gripper finger 16.2 and the third gripper finger 16.3 may be mounted on a support plate 22, which projects beyond the outer circular contour of the base link 12 inwards in the direction of the first axis of rotation D1 of the robot gripper 11, as shown, for example, in FIG. 6. The support plate 22 may be formed by a circular segment disk having a circular arc-shaped contour edge K1, which is attached to an edge region of the main gripper body 12; and said circular segment disk projects beyond a circular segment-shaped region of the base link 14 inwards in the direction of the first axis of rotation D1 of the robot gripper 11. This means that the base link 14 can be rotated, as shown, for example, in FIG. 8, in such a way that it passes beneath the support plate 22, as a result of which, the first gripper finger 16.1, which is mounted on the base link 14, can be rotated directly up against the second gripper finger 16.2 or the third gripper finger 16.3, as can be seen in FIG. 11 and FIG. 12a, FIG. 12b. Consequently the first gripper finger 16.1 can be rotated up against the second gripper finger 16.2 or the third gripper finger 16.3 as far as up to a collision, so that the first gripper finger 16.1 with the second gripper finger 16.2 or with the third gripper finger 16.3 can be rotated towards each other as far as into a closed position, so that even very thin parts, such as, for example, thin sheet metals, individual sheets of paper or thin pins 23 can be grasped.

[0097] In a modification of a circular segment disk-shaped support plate 22 a straight edge K2 (FIG. 6) of the chord may be replaced by a recessed edge K3 (FIG. 10 to FIG. 12b). Such a recessed edge K3 may be formed in a region of the chord on the support plate 22, said region lying between the second gripper finger 16.2 and the third gripper finger 16.3, which is arranged so as to be spaced apart from the second gripper finger 16.2. Such a recess allows the first gripper finger 16.1 to be moved even between the second gripper finger 16.2 and the third gripper finger 16.3, so that the first gripper finger 16.1 can be positioned between the second gripper finger 16.2 and the third gripper finger 16.3 at least partially or even completely. An inward movement is also possible, if the edge is not recessed, but for this purpose the gripper fingers, in particular, the first gripper finger, exhibit a corresponding shape, in particular, in the region above the gripper surface.

[0098] In the design variant shown in FIG. 13, the first gripper finger 16.1 is designed to be non-driven and, thus, is rigidly attached to the finger support 17 or to the intermediary link 18.

[0099] As the variants in FIG. 14a and FIG. 14b show, the first gripper finger 16.1 may be attached to the finger support 17 by means of a lever 20, which aligns the first gripper finger 16.1 with its longitudinal extent at least substantially or exactly parallel to the third axis of rotation D3 of the third pivot joint 15.3, which bears the finger support 17, and is arranged at a distance A from the third axis of rotation D3.

[0100] Consequently the first gripper finger 16.1 and/or the second gripper finger 16.2 and/or the third gripper finger 16.3 may be formed, for example, by an L-shaped link, where in this case a first leg 51, which is connected to the finger support 17 and which belongs to the L-shaped link, forms the lever 20; and the other leg, i.e., a second leg S2 of the L-shaped link, forms a gripping section of the first gripper finger 16.1, which is aligned in its longitudinal extent parallel to the axes of rotation D1-D3 of the pivot joints 15.1 to 15.3 of the robot gripper 11, as shown in FIG. 14a and FIG. 14b.

[0101] FIG. 15a shows a first configuration, in which the robot gripper 11 is designed with gripper fingers 16.1, 16.2, 16.3, projecting laterally beyond the main gripper body 12, in the form of L-shaped links, for the purpose of gripping very small objects 27.1, in particular, in the vicinity of a boundary wall 28.

[0102] In the design variant shown, the second gripper finger 16.2 or the second gripper finger 16.2 and the third gripper finger 16.3 may be designed in their shape such that said fingers project laterally with their respective longitudinal extent beyond the main gripper body 12. For this purpose the first gripper finger 16.1 exhibits a shape that allows it to grasp very small objects 27.1 even outside the outer contour of the main gripper body 12. In this case the second gripper finger 16.2 and the first gripper finger 16.1 can be moved very close to the boundary wall 28, so that in this case the main gripper body 12 is located at a greater distance from the boundary wall 28.

[0103] FIG. 15b shows a second configuration, in which the robot gripper 11 is designed with gripper fingers 16.1, 16.2, 16.3, projecting beyond the main gripper body 12 on diametrically opposite sides, in the form of L-shaped links, for the purpose of gripping objects 27.2 that are larger than the main gripper body 12.

[0104] In this configuration of the gripper fingers 16.1, 16.2, 16.3, i.e., in alternative joint positions for the first gripping finger 16.1 or the second gripper finger 16.2 and/or the third gripper finger 16.3, the first gripper finger 16.1 projects, as shown, laterally beyond the main gripper body 12 on a side, diametrically opposite the second gripper finger 16.2 and the third gripper finger 16.3. This arrangement may result in a pliers opening width between the first gripper finger 16.1 and the second gripper finger 16.2 or the third gripper finger 16.3 that is much larger than the width of the main gripper body 12 itself.

[0105] FIG. 16 shows an exemplary design variant, in which the first gripper finger 16.1 comprises at least one outer shell wall section 21, which is designed to be adjustable, as indicated by the arrow P, with respect to a center axis Z of the first gripper finger 16.1 at a distance from this center axis Z, said center axis extending more or less parallel to the longitudinal extent of the first gripper finger 16.1.

[0106] In a specific embodiment, as shown in FIG. 16, the first gripper finger 16.1 may have a plurality of separately adjustable or elastic outer wall sections 21, which are arranged in the longitudinal extent of said first gripper finger in such a way that they are superimposed on each other. In the case of a first gripper finger 16.1, which is triangular in cross section, two of three of the flat outer walls may have a plurality, for example, seven vertically superimposed, each separately adjustable, outer wall sections 21. Each outer wall section 21 may be formed by a spring bracket, which is attached to the first gripper finger 16.1.

[0107] While the present invention has been illustrated by a description of various embodiments, and while these embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. The various features shown and described herein may be used alone or in any combination. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and method, and illustrative example shown and described. Accordingly, departures may be made from such details without departing from the spirit and scope of the general inventive concept.