Device for holding objects

Abstract

The invention relates to a device for holding objects, wherein the device has a ring-shaped shaped mat (2) which contains granular material (4) and which surrounds a suction chamber (6) which is open to at least one side, wherein the shaped mat (2) and the suction chamber (6) have an interface (12, 26) for a negative pressure source, characterized in that the suction chamber (6) is covered at the open side by a gas-permeable cover (40).

Description

Technical Field

[0001] The present invention relates to a device for holding an object, wherein the device has an annular molding pad containing particulate matter and surrounding a suction cavity open to at least one side, wherein the molding pad and the suction cavity have an interface for a negative pressure source. Background Technology

[0002] Such devices are known in the prior art and are used to hold, manipulate, and / or transport objects. To hold an object by this device, a forming pad is brought into contact with the object. The forming pad is made of a flexible and / or elastic material, thus deforming under pressure applied by the object to the forming pad. This causes particles located within the forming pad to be moved. Subsequently, a negative pressure is applied to the forming pad. This negative pressure comes from a negative pressure source, such as a pump, which may be part of the device, but is not required to be. Such devices are commonly used in assembly shops as end effectors for robots, which may be connected to a central negative pressure supply system or have their own pumps. By applying negative pressure to the forming pad, air is drawn out of the forming pad, and the forming pad solidifies in the position it is in when in contact with the workpiece to be grasped. In this way, the device adapts very well to the external shape, geometry, and / or form of the object.

[0003] Such devices initially feature a forming pad with large end faces that preferably fully abut against the object to be held, causing the forming pad to deform. A further development of such devices features an annular forming pad. The annular forming pad can be designed to be ring-shaped, although this is not mandatory. "Annular" means that the cross-section of the forming pad has a closed outer contour and a closed inner contour. The outer contour is formed, for example, by an outer wall, and the inner contour by an inner wall. Between the inner and outer walls is a volume for accommodating particles. The forming pad is secured to a retainer on one side for mounting the device to another component (e.g., a robotic arm). On the opposite side, the forming pad is bounded by the end faces. Typically, the end faces are used to contact the object to be held.

[0004] Inside the inner wall is a suction cavity, which is surrounded by a molding pad and defined by the inner wall of the molding pad. The suction cavity has an interface for a negative pressure source. This interface is preferably located on the side of the suction cavity facing the device holder. On the opposite side, i.e., the side facing the object to be held, the suction cavity is open.

[0005] When holding an object, the negative pressure applied to the molding pad causes the pad to solidify, thus maintaining its shape to conform to the object. The negative pressure applied to the suction chamber creates a suction effect on the object to be held. This force holds the object on the device.

[0006] The aforementioned characteristics and features are not only present and advantageous in prior art devices, but also advantageous for devices according to embodiments of the present invention.

[0007] The downside is that such devices can cause deformation of the object being held, especially in the suction chamber area, particularly when the object is very flexible. This can lead to permanent deformation, such as bending and flexing, or even damage to the object. Summary of the Invention

[0008] Therefore, the objective of this invention is to further develop this type of device so that flexible objects can also be better protected.

[0009] This invention addresses the proposed task through a device with preferred technical features, characterized in that the suction chamber is covered on its open side by a breathable covering. Through this covering, the suction effect generated by the negative pressure within the suction chamber, and thus the retaining force applied to the object, continues to act on the object. In this context, it is referred to herein as a suction chamber open to one side. The breathable covering ensures that even particularly flexible objects are not, or at least no longer, forcefully drawn into the suction chamber as in the prior art, thus preventing deformation and damage. Preferably, the breathable covering is made of a flexible but inelastic material. Therefore, it can conform to the shape that changes during the molding process.

[0010] Preferably, the breathable covering is made of textiles or fabrics, particularly preferably woven fabrics.

[0011] Preferably, the breathable covering is arranged on the molding pad, particularly bonded and / or welded to the molding pad.

[0012] In a preferred design, the molding pad has an inner wall facing the suction cavity, an outer wall facing away from the suction cavity, and an end side or end face connecting the inner wall and the outer wall, wherein the breathable covering is arranged on the edge between the inner wall and the end side.

[0013] Preferably, the breathable cover includes at least one stabilizing strip having higher stiffness, particularly flexural stiffness, than the rest of the breathable cover. Particularly preferably, at least one stabilizing strip extends from the inner wall of the molded pad to the inner wall of the molded pad.

[0014] It has proven advantageous that the molding pad and the suction chamber can be subjected to negative pressure separately from each other.

[0015] Preferably, the molding pad and the suction chamber have a common interface for a negative pressure source, wherein the device preferably has a valve through which negative pressure can be distributed to the molding pad and / or the suction chamber. Thus, the device has a separate interface on which the negative pressure source can be located, and through which negative pressure can be applied to both the molding pad and the suction chamber when the negative pressure source is connected. From this interface, one branch leads to the molding pad, and another branch leads to the suction chamber. Both branches are part of a common conduit originating from this interface. The valve is preferably located at the bifurcation. The valve is preferably configured to supply negative pressure only to the molding pad or only to the suction chamber. Furthermore, the valve is preferably configured to supply negative pressure to both the molding pad and the suction chamber, wherein the valve is particularly preferably capable of supplying negative pressure to the molding pad and the suction chamber to different degrees. This can be achieved, for example, by the valve changing the flow resistance in the branch leading to the molding pad and the flow resistance in the branch leading to the suction chamber. This can be achieved, for example, by one or more throttling valves.

[0016] A method for holding an object, comprising using a device according to an embodiment of the invention, the method itself constituting an independent invention. In this method, a shaping pad is first adapted to the geometry, external shape, and / or morphology of the object to be held. This is preferably achieved by bringing the shaping pad into contact with the object, wherein the shaping pad is not yet subjected to negative pressure. It is flexible and deformable, thus adapting to the object.

[0017] In this state, a negative pressure is applied to the suction chamber. Thus, a holding force is applied to the object at this early stage, which can further cause the molding pad to adapt to the shape, geometry, and / or form of the object.

[0018] After this deformation of the molding pad, a negative pressure is applied to it. As explained above, the molding pad loses its flexibility and is fixed in its presented shape. The negative pressure applied to the suction chamber also prevents the molding pad from moving relative to the object during the curing process.

[0019] Releasing the object from the device is preferably done in reverse order. After the object has been held for a sufficient period of time, the negative pressure on the suction chamber is first removed. For this purpose, it is sufficient to close the valve in the conduit that directs the externally applied negative pressure to the suction chamber. Alternatively, the suction chamber can be ventilated, for example, by opening the connection between the suction chamber and the surrounding environment. Pressure equilibrium then occurs, and the holding force on the object generated by the negative pressure in the suction chamber can no longer be maintained. Preferably, after this, but at least staggered in time, the negative pressure on the molding pad is no longer applied, or even the molding pad is ventilated.

[0020] Preferably, an annular sealing lip is arranged on the molding pad.

[0021] The rationale behind this design is that the high energy consumption of existing devices is at least partly due to the fact that, although the molding pad adapts almost optimally to the contour, shape, and form of the object when negative pressure is applied, the contact between the molding pad and the object to be held is not sufficiently sealed. Because of this insufficient seal, air flows into the suction chamber under negative pressure, causing a pressure drop there. This pressure drop means a reduction in the pressure difference between the negative pressure provided by the negative pressure source and the ambient pressure. Therefore, the negative pressure within the suction chamber weakens, and the pressure within the suction chamber increases. This leakage is reduced or even completely avoided by the sealing lip according to the invention, thereby making it easier and therefore with less energy consumption to maintain the pressure difference between the suction chamber pressure required to hold the object and the ambient pressure.

[0022] The sealing lip is designed to be annular. This can be circular, but it is not required to be. Any closed contour or trajectory along which the sealing lip extends is considered annular in the sense of this invention.

[0023] Preferably, the molding pad has an inner wall facing the suction cavity, an outer wall facing away from the suction cavity, and an end side connecting the inner wall and the outer wall, wherein the sealing lip is disposed on the end side. The end side typically faces the object to be held. Preferably, the annular sealing lip extends around an opening leading to the suction cavity.

[0024] In a preferred design, the sealing lip is integrally or integrally formed with the molding pad. For example, a molding pad with a sealing lip can be injection molded, wherein both the shape of the molding pad and the shape of the sealing lip are present in the injection mold, and they are cast together.

[0025] Alternatively, the sealing lip can also be fixed to the molding pad, for example, by bonding, welding, or other means. Advantageously, the connection between the sealing lip and the molding pad should be as airtight as possible along the entire extension of the sealing lip to avoid the aforementioned leakage.

[0026] The end face of the molding pad is annular. It can be a ring, but this is not necessary. Importantly, this end face forms an opening to the suction cavity. The ring formed by this end face has a width corresponding to the distance between the inner and outer walls. Preferably, this width is constant in the circumferential direction. The end face has a radially inner portion and a radially outer portion. The radially inner portion is preferably half, one-third, or one-quarter of the radially inner portion of the end face. The radially inner portion of the end face is the portion adjacent to the edge of the inner wall. The radially outer portion is preferably half, one-third, or one-quarter of the radially outer portion of the end face. The radially outer portion of the end face is the portion adjacent to the edge of the outer wall.

[0027] Preferably, the sealing lip is disposed in the radially inner portion of the end side. This has the advantage of positioning the sealing lip close to the suction chamber where negative pressure is applied, which needs to be sealed off from the environment. Furthermore, this arrangement allows for the use of a relatively long sealing lip without it protruding radially outward from the molding pad.

[0028] In a preferred design, the sealing lip does not protrude radially outward from the molding pad.

[0029] Preferably, the sealing lip has a first portion in which it bends away from the molding pad. It also has a second portion in which it bends toward the molding pad. In this way, it can act as a spacer between the end side of the molding pad and the object to be held, so that the sealing lip is also subjected to the negative pressure applied to the suction chamber. Attached Figure Description

[0030] With the aid of the accompanying drawings, some embodiments of the device for holding an object will be described in more detail below. The drawings are as follows.

[0031] Figure 1 A schematic cross-sectional view of such a device according to a first embodiment is shown.

[0032] Figure 2 Show Figure 1 A schematic cross-sectional view of the device in contact with an object.

[0033] Figure 3 A schematic cross-sectional view of such a device according to a second embodiment is shown.

[0034] Figure 4 A schematic cross-sectional view of such a device according to a third embodiment is shown.

[0035] Figure 5 Show Figure 4 A schematic cross-sectional view of the device in contact with an object.

[0036] Figure 6 A schematic cross-sectional view of such a device according to the fourth embodiment is shown. Detailed Implementation

[0037] Figure 1 A schematic cross-sectional view of a device for holding an object is shown. The device has an annular forming pad 2 containing particles 4. The forming pad 2 surrounds an annular suction cavity 6, which... Figure 1The middle part is open downwards. The molding pad 2 is fixed to the interface member 10 by means of a connecting element 8. The interface member 10 is arranged, for example, on a robot arm (not shown). On the interface member 10, the device has an interface 12 for a negative pressure source, through which air can be drawn from the intermediate space 14 between the interface member 10 and the connecting element 8 when the interface 12 is connected to the negative pressure source. The connecting element 8 has a through hole 16 that connects the intermediate space 14 to the suction chamber 6. Therefore, if a negative pressure is applied at the interface 12 by means of a negative pressure source (e.g., a pump) connected to the interface 12, air is also drawn from the intermediate space 14 and from the suction chamber 6 through the through hole 16.

[0038] In the illustrated embodiment, the interface 10 has two valves 18 that, when open, connect the intermediate space 14 to the annular sub-cavity 20. The connecting element 8 has two additional channels 22 that connect the sub-cavity 20 to the molding pad 2. Therefore, when the valves 18 are open, air is also drawn from the molding pad 2 by a negative pressure source located at the interface 12, causing the particles 4 to be securely surrounded by the outer shell 24 of the molding pad 2. The interface also has a second interface 26 that can be connected to a negative pressure source. Thus, different negative pressures can be applied to the molding pad 2 and the suction chamber 6 when the valves 18 are closed.

[0039] A stop 28 and a sensor 30 are also arranged in the suction chamber 6, which can be used to monitor the approach of the object to be held. In the outer casing 24... Figure 1 Two sealing lips 32 are arranged on the lower side as shown. This creates a seal between the contact area of ​​the housing 24 and the object to be held. This makes it easier to maintain a negative pressure within the suction chamber 6, which applies suction to the object to be held.

[0040] Figure 2 It shows Figure 1 The device is in contact with the object 34. It can be seen that the sealing lip 32 is pressed against the object 34. Due to the negative pressure generated within the suction chamber 6, the object 34 is adsorbed onto the molding pad 2. The negative pressure generated within the molding pad ensures that the outer shell 24 of the molding pad 2 is tightly attached to the particulate matter 4, thereby preventing the individual components of the particulate matter 4 from moving relative to each other.

[0041] Figure 3 A schematic cross-sectional view of the device according to the second embodiment is shown. The sealing lip 32 has a thickened portion at its end, thereby improving the sealing performance. The sealing lip 32 is part of the central sealing element 36, which replaces the central portion of the connecting element 8 and defines the boundary of the suction cavity 6 in the direction toward the interface 10. The interface 12 is connected to the suction cavity 6 via a conduit 38.

[0042] Figure 4The third embodiment of the device for holding an object, shown in a schematic cross-sectional view, essentially corresponds to... Figure 1 The illustration in the image. However, Figure 4 The device shown does not have a sealing lip 32. It has a cover 40, which is designed to be breathable and defines the boundary of the suction chamber 6 from below, i.e., towards the object to be held. Because the cover 40 is breathable, the negative pressure generated in the suction chamber, through a negative pressure source (not shown) arranged at the interface 12, will exert a holding force on the object. Figure 5 and Figure 6 The diagram corresponds to Figure 2 and Figure 3 The illustration. However, Figure 5 and Figure 6 The device design shown does not have a sealing lip 32. They each have a breathable covering.

[0043] List of reference numerals in the attached diagram: 2 Molding Pad 4. Particulate matter 6. Suction chamber 8 Connecting elements 10 Interface components 12 interfaces 14 Intermediate Space 16 through holes 18 valves 20 secondary cavities 22 channels 24. Outer shell 26 Second Interface 28 Stop 30 sensors 32 Sealing Lip 34 objects 36 Sealing elements 38 Pipeline 40. Coverings.

Claims

1. A device for holding an object, wherein, The device has an annular molding pad (2), the molding pad Contains particulate matter (4), and Surrounding the suction chamber that is open to at least one side (6). The molding pad (2) and the suction chamber (6) have interfaces (12, 26) for a negative pressure source. Its features are, The suction chamber (6) is covered on the open side by a breathable covering (40).

2. The apparatus according to claim 1, characterized in that, The breathable covering (40) is made of fabric.

3. The apparatus according to claim 1 or 2, characterized in that, The breathable covering (40) is arranged, in particular, bonded and / or welded to the molded pad (2).

4. The apparatus according to claim 3, characterized in that, The molding pad (2) has an inner wall facing the suction cavity (6), an outer wall away from the suction cavity (6), and an end side connecting the inner wall and the outer wall, wherein the breathable cover (40) is arranged at the edge between the inner wall and the end side.

5. The apparatus according to any one of the preceding claims, characterized in that, The breathable cover (40) includes at least one stabilizing strip that has higher stiffness, particularly flexural stiffness, than the rest of the breathable cover (40).

6. The apparatus according to claim 5, characterized in that, At least one stabilizing strip extends from the inner wall of the molding pad (2) to the inner wall of the molding pad (2).

7. The apparatus according to any one of the preceding claims, characterized in that, The molding pad (2) and the suction chamber (6) can be subjected to negative pressure separately from each other.

8. The apparatus according to any one of the preceding claims, characterized in that, The molding pad (2) and the suction chamber (6) have a common interface (12) for a negative pressure source, wherein the device preferably has a valve (18) through which negative pressure can be distributed to the molding pad (2) and / or the suction chamber (6).

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