SAFETY COUPLING AND HANDLING SYSTEM COMPRISING A SAFETY COUPLING

Abstract

A safety coupling for connecting an end effector to a manipulator, comprising a manipulator coupling portion for connecting the safety coupling to the manipulator, an end effector coupling portion for connecting the safety coupling to the end effector, a lowering device, which connects the manipulator coupling portion and the end effector coupling portion to one another in a way that the end effector coupling portion and an end effector optionally coupled to the end effector coupling portion can descend relative to the manipulator coupling portion, with control, in particular with automatic braking, as a result of gravity, and a securing device, which can assume a normal configuration and an emergency configuration, the securing device blocking the lowering device when the securing device is in the normal configuration and releasing the lowering device when the securing device is in the emergency configuration.

Claims

1. A safety coupling for connecting an end effector to a manipulator, the safety coupling comprising: a manipulator coupling portion for connecting the safety coupling to the manipulator; an end effector coupling portion for connecting the safety coupling to the end effector; a lowering device, which connects the manipulator coupling portion and the end effector coupling portion to one another in such a way that the end effector coupling portion and an end effector optionally coupled to the end effector coupling portion can descend relative to the manipulator coupling portion, with control, with automatic braking, as a result of gravity; and a securing device, having a normal configuration mode and an emergency configuration mode, the securing device blocking the lowering device when the securing device is in the normal configuration mode and releasing the lowering device when the securing device is in the emergency configuration mode.

2. The safety coupling according to claim 1, wherein the securing device is designed in such a way that, having a trigger mechanism in such a way that, the securing device automatically switches from the normal configuration mode into the emergency configuration mode when a predefined triggering condition occurs.

3. The safety coupling according to claim 2, wherein the triggering condition is one or more of the following conditions: a. interruption of an electrical power supply to the safety coupling; b. interruption of a compressed-air supply to the safety coupling; c. interruption of a negative-pressure supply to the safety coupling; d. exceeding of a threshold value of a leakage in an end effector connected to the safety coupling; e. undershooting or exceeding of a threshold value of a negative pressure applied to the safety coupling; f. receiving of an emergency signal by a receiving device of the safety coupling.

4. The safety coupling according to claim 1, wherein the lowering device comprises a length-adjustable connection device, which connects the manipulator coupling portion and the end effector coupling portion to one another.

5. The safety coupling according to claim 4, wherein the connection device comprises one or more of the following devices: a. a cable connection, which comprises a mechanically or fluidically braked cable pulley and/or a frictionally braked cable; b. a mechanically or fluidically braked telescopic rod, which is connected, at one end, to the manipulator coupling portion and, at the other end, to the end effector coupling portion; c. a damped spring, which is connected, at one end, to the manipulator coupling portion and, at the other end, to the end effector coupling portion; d. a lifting tube, to which negative pressure can be applied and which is connected, at one end, to the manipulator coupling portion and, at the other end, to the end effector coupling portion; e. a fluidically braked piston.

6. The safety coupling according to claim 1, wherein the securing device fixes the manipulator coupling portion and the end effector coupling portion at a fixed distance from one another, mechanically, further with form closure, friction closure and/or force closure, magnetically and/or by means of negative pressure, when the securing device is in the normal configuration mode.

7. The safe coupling according to claim 1, wherein the securing device comprises an actuatable permanent magnet or an electromagnet, by means of which the manipulator coupling portion and the end effector coupling portion can be fixed at a fixed distance from one another.

8. The safety coupling according to claim 2, wherein the securing device comprises an actuating element, which can be moved between a first switching position and a second switching position, the actuating element being designed in such a way that, in the normal configuration mode of the securing device, the actuating element is in the first switching position and, when the triggering condition occurs, the actuating element is automatically transferred into the second switching position.

9. The safety coupling according to claim 8, wherein the actuating element comprises a wire or bar made of a shape memory material.

10. The safety coupling according to claim 8, wherein the actuating element is an actuatable spring-preloaded actuation piston.

11. The safety coupling according to claim 10, wherein the actuation piston is designed in such a way that, when the actuation piston is actuated, when compressed air is applied to the actuation piston, against the spring preload, the actuation piston is in the first switching position and, in the event of interruption of the actuation, in the event of interruption of a compressed-air supply, the actuation piston is automatically transferred by the spring preload into the second switching position.

12. The safety coupling according to claim 10, wherein, in the first switching position, the actuation piston interacts with the manipulator coupling portion and the end effector coupling portion in such a way that the manipulator coupling portion and the end effector coupling portion are fixed at a fixed distance from one another by the actuation piston.

13. The safety coupling according to claim 8, wherein the securing device comprises a fixing device, which can assume a locking configuration and a release configuration, wherein the fixing device fixes the manipulator coupling portion and the end effector coupling portion at a fixed distance from one another when the fixing device is in the locking configuration and this fixing is released when the fixing device is in the release configuration, and wherein the fixing device interacts with the actuating element in such a way that, by transfer of the actuating element from the first switching position into the second switching position, the fixing device can be transferred from the locking configuration into the release configuration.

14. The safety coupling according to claim 1, wherein the fixing device comprises two toothed rings, which can be rotated relative to one another in such a way that they can assume a locking configuration and a release configuration, wherein, in the locking configuration, the toothed rings connect the manipulator coupling portion and the end effector coupling portion to one another and wherein, in the release configuration, the toothed rings are displaceable relative to one another in such a way that the manipulator coupling portion and the end effector coupling portion can be moved relative to one another.

15. A handling system comprising: the manipulator, the end effector, and the safety coupling according to claim 1, wherein the end effector is fastened to the manipulator by means of the safety coupling.

16. The safety coupling according to claim 5, wherein the damped spring is a coil spring and the fluidically braked piston is an air-braked piston.

17. The safety coupling according to claim 8, wherein the actuating element is a pneumatically actuatable spring-preloaded actuation piston.

Description

IN THE DRAWINGS

[0037] FIG. 1 is a simplified schematic representation of a handling system;

[0038] FIG. 2 is a simplified schematic representation of a safety coupling in normal configuration;

[0039] FIG. 3 is a simplified schematic representation of a safety coupling in emergency configuration; and

[0040] FIG. 4a-c are simplified schematic representations of the safety coupling with end effector coupled thereto, in different operating states, for explaining the functioning of the safety coupling.

[0041] In the following description and in the figures, identical reference signs are in each case used for identical or corresponding features.

[0042] FIG. 1 shows a handling system, which is denoted as a whole by reference sign 10. The handling system 10 comprises a manipulator 12 and an end effector 14 for gripping an object 16. The manipulator 12 can be, for example, a robot, in particular an industrial robot or a lightweight robot.

[0043] In the example shown, the end effector 14 is in the form of a suction gripping device 18. As shown schematically in FIG. 1, the suction gripping device 18 comprises, by way of example, a support frame 20 on which one or more, in the example shown two, suction bodies 22 for suctioning the object 16 are arranged.

[0044] In embodiments not shown, the end effector 14 can also be in the form of a mechanical gripper or a magnetic gripper, for example.

[0045] The handling system 10 also comprises a safety coupling 24, by means of which the end effector 14 is fastened, in particular releasably fastened, to the manipulator 12. As shown in FIG. 1, the safety coupling 24 is arranged between the manipulator 12 and the end effector 14.

[0046] The safety coupling 24 comprises a manipulator coupling portion 26 for coupling the safety coupling 24 to the manipulator 12. For example, the manipulator coupling portion 26 can be screwed to a connection flange 28 of the manipulator 12 or connected by means of a bayonet connection.

[0047] The safety coupling 24 also comprises an end effector coupling portion 30 opposite from the manipulator coupling portion 26, for coupling the end effector 14 to the safety coupling 24 and thus to the manipulator 12. The end effector coupling portion 30 can comprise, for example, a quick-change coupling for releasably coupling the end effector 14.

[0048] The safety coupling 24 also comprises a lowering device 32 (see FIG. 3), which is designed to let the end effector coupling portion 30, the end effector 14 coupled to the end effect coupling portion, and an object 16 optionally held on the end effector 14 descend relative to the manipulator coupling portion 26 with control, in particular at reduced speed, as a result of gravity. The direction in which gravity acts is shown with the arrow 33 in the figures.

[0049] The lowering device 32 comprises a length-adjustable connection device 34, by means of which the manipulator coupling portion 26 and the end effector coupling portion 30 are connected to one another (see FIG. 3).

[0050] In the example shown, the connection device 34 comprises a telescopic rod 36, which is connected, at one end, to the manipulator coupling portion 26 and, at the other end, to the end effector coupling portion 30.

[0051] The telescopic rod 36 is preferably mechanically or fluidically braked, so that the end effector coupling portion 30 (together with an end effector 14 arranged on the end effector coupling portion and an object 16 held in turn on the end effector) can descend with control in the direction of gravity (see arrow 33).

[0052] FIG. 2 shows the safety coupling 24 with the lowering device 32 retracted. FIG. 3 shows the safety coupling 24 with the lowering device 32 extended.

[0053] As shown by way of example in FIGS. 2 and 3, the safety coupling 24 can comprise a two-part or multi-part housing 38, with a first housing portion 40, which is connected to the manipulator coupling portion 26, and a second housing portion 42, which is connected to the end effector coupling portion 30. The housing portions 40, 42 are preferably designed in such a way that they enclose the lowering device 32 when the lowering device is in the retracted configuration (see FIG. 2). The lowering device 32 is then protected from environmental influences by the housing 38. As the lowering device 32 extends, the housing portions 40, 42 then become separated from one another (see FIG. 3).

[0054] As explained above, the lowering device 32 is provided to allow, in an emergency situation in which a process sequence of the handling system 10 is disrupted (for example as a result of a failure of the electrical power supply), the end effector 14 and an object 16 held on the end effector to descend with control into a stable configuration on a support, for example onto a building floor 44 (see FIG. 4c). In normal operation of the handling system 10, however, the lowering device 32 should be blocked, so that the end effector coupling portion 30 and the manipulator coupling portion 26 are fixed relative to one another.

[0055] For this purpose, the safety coupling 24 comprises a securing device 46 (only schematically shown in the figures), which can assume a normal configuration shown in FIGS. 2 and 4a and an emergency configuration shown in FIGS. 3, 4b, and 4c.

[0056] In the normal configuration, the securing device 46 is configured in such a way that it fixes the end effector coupling portion 30 and the manipulator coupling portion 26 at a fixed distance from one another in such a way that the lowering device 32 is blocked, i.e. extension of the telescopic rod 36 is not possible (see FIG. 2). In the emergency configuration, in contrast, the securing device 46 is configured in such a way that fixing of the end effector coupling portion 30 and of the manipulator coupling portion 26 by the securing device 46 is released, so that the lowering device 32 is released (see FIG. 3).

[0057] The securing device 46 is preferably designed in such a way that, when a predefined triggering condition occurs, the securing device independently switches from the normal configuration (see FIG. 2) into the emergency configuration (see FIG. 3). The triggering conditions can be, for example, an interruption of an electrical power supply to the safety coupling 24, an interruption of a compressed-air supply to the safety coupling 34, an interruption of a negative-pressure supply to the safety coupling 24, an exceeding of a threshold value of a leakage in the end effector 14, an undershooting or exceeding of a threshold value of a negative pressure applied to the safety coupling 24, or the receiving of an emergency signal by an optional receiving device (not shown) of the safety coupling 24.

[0058] As explained above, different embodiments of the securing device 46 are possible. In the figures, an embodiment of the securing device 46 with electromagnets 48 is shown by way of example. As explained in detail below, the electromagnets 48 are designed to connect the manipulator coupling portion 26 and the end effector coupling portion 30 to one another by magnetic force when the electromagnets are actuated (normal configuration of the securing device 46) and to allow movement of the end effector coupling portion 30 relative to the manipulator coupling portion 26 when the actuation is eliminated (e.g. as a result of an interruption of the electrical power supply to the electromagnets 48).

[0059] In the specific example, the securing device 46 comprises two connection arms 50, which are each pivotably retained on the second housing portion 42 connected to the end effector coupling portion 30 and at the free end of each of which an electromagnet 48 is provided. When the electromagnets 48 are in the actuated state (see FIGS. 2 and 4a), the first housing portion 40 and the second housing portion 42 are connected to one another by the magnetic retaining force of the electromagnets 48. In the event of an interruption of the electrical power supply to the electromagnets 48 (for example as a result of a power failure) and the associated elimination of the magnetic retaining force, fixing of the end effector coupling portion 30 and the manipulator coupling portion 26 is released (see FIG. 4b). In particular, the connection arms 50 can fold away from their contact on the first housing portion 40 (see FIG. 4b). As a result, the lowering device 32 is released and the end effector 14 can descend together with the object 16 as a result of gravity, in particular until the object 16 has reached a safe position on the floor 44. In this way, an automatic securing mechanism is created, which makes it possible to transfer an object 16 held on the end effector 14 into a stable configuration in the event of a failure of an electrical power supply.