Connecting device and magnetic gripper comprising such a connecting device

Abstract

The present invention relates to a connecting device (20) for a magnetic gripper, comprising a membrane (22) having first and second opposite faces (24, 26), an annular portion (28) projecting from the second face along the periphery of the membrane and deformable fixing means (40) projecting from the annular portion.

Description

DESCRIPTION TITLE: Magnetic binding and gripper device comprising such a binding device This patent application claims priority from French patent application FR22 / 02816, which will be considered as forming an integral part of this description. technical field

[0001] This description relates in general to magnetic gripper linkage devices and magnetic grippers comprising such linkage devices. Previous technique

[0002] Magnetic grippers are used for handling ferromagnetic mechanical parts. One example of an application is in the automotive industry, where magnetic grippers are used to handle mechanical parts such as gears, hubs, etc. For this purpose, the magnetic gripper is brought close to the mechanical part to be handled, and a magnetic device within the gripper is activated so that the mechanical part adheres to the gripper by magnetic attraction. When the mechanical part is brought to the desired position, the magnetic device is deactivated to release the part.

[0003] The handling of the mechanical part by the gripper must not damage the mechanical part. Furthermore, it is desirable to be able to use the same gripper with mechanical parts of different dimensions. The intensity of the magnetic field decreases with distance from the gripper head. The manufacturing cost of the magnetic gripper depends in particular on the maximum intensity of the magnetic field produced by the gripper's magnet. It is desirable that the manufacturing cost of the gripper magnetic field is reduced, which implies that the mechanical part being handled is as close as possible to the gripper head so that the attractive forces exerted on the mechanical part allow it to be handled without requiring the generation of a strong magnetic field. Summary of the invention

[0004] Thus, one object of an embodiment is to overcome all or part of the disadvantages of known magnetic grippers.

[0005] Another objective of an embodiment is to be able to use the magnetic gripper with mechanical parts of different sizes.

[0006] Another objective is to avoid direct physical contact between the mechanical part and a rigid, particularly metallic, part of the magnetic gripper, especially with mechanical parts of different sizes.

[0007] To this end, one embodiment provides a magnetic gripper connection device comprising a membrane having first and second opposite faces, an annular portion projecting from the second face along the periphery of the membrane and deformable fastening means projecting from the annular portion.

[0008] According to one embodiment, the membrane and the annular portion form a single piece.

[0009] According to one embodiment, the fastening means include a deformable lip.

[0010] According to one embodiment, the membrane and the annular portion are made of a flexible material.

[0011] According to one embodiment, the thickness of the membrane is between 0.05 mm and 5 mm.

[0012] According to one embodiment, the thickness of the annular portion is between 5 mm and 15 mm.

[0013] According to one embodiment, the maximum lateral dimension of the membrane is between 10 mm and 100 mm.

[0014] According to one embodiment, the connecting device includes an axis of revolution symmetry.

[0015] One embodiment also provides for a magnetic gripper comprising a magnetic gripping tool and a connecting device as defined previously.

[0016] According to one embodiment, the magnetic gripping tool comprises a head having a third face, the membrane covering the entire third face, the second face being in physical contact with the third face.

[0017] According to one embodiment, the third face is flat.

[0018] According to one embodiment, the magnetic gripper includes a groove into which the deformable fastening means penetrate at least partially. Brief description of the drawings

[0019] These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the attached figures, among which:

[0020] Figure 1 is a perspective view, partially exploded, of an embodiment of a magnetic gripper;

[0021] Figure 2 is a side view of the gripper in Figure 1;

[0022] Figure 3 is a side cross-sectional view of the gripper in Figure 1;

[0023] Figure 4 is a detailed view of Figure 3;

[0024] Figure 5 is a perspective view of one embodiment of a linking device for the gripper of Figure 1;

[0025] Figure 6 is a top view of the linking device in Figure 5;

[0026] Figure 7 is a side cross-sectional view of the linking device in Figure 5;

[0027] Figure 8 is a cross-sectional view of part of the gripper of Figure 1 during the manipulation of a small object;

[0028] Figure 9 is a cross-sectional view of part of the gripper in Figure 1 during the manipulation of a medium-sized object; and

[0029] Figure 10 is a cross-sectional view of part of the gripper of Figure 1 during the manipulation of a large object. Description of the implementation methods

[0030] The same elements have been designated by the same reference numerals in the different figures. In particular, structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties.

[0031] For the sake of clarity, only the steps and elements necessary for understanding the described embodiments have been shown and detailed. In particular, the structure of a magnetic gripper has not been detailed.

[0032] In the description that follows, when referring to absolute positional qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative terms such as "above", "below", "superior", "inferior", etc., or orientation qualifiers such as "horizontal", "vertical", etc., refers, unless otherwise specified, to the orientation of the figures or to a ... in a normal position of use.

[0033] Unless otherwise specified, the expressions "approximately", "roughly", "about", and "on the order of" mean within 10%, preferably within 5%.

[0034] Figure 1 is a schematic, partially exploded perspective view of an embodiment of a magnetic gripper 10. Figure 2 is a partial, schematic side view of the gripper 10. Figure 3 is a cross-sectional view of Figure 2 along section plane III-III. Figure 4 is a detailed view of Figure 3.

[0035] The magnetic gripper 10 comprises a magnetic gripping tool 12 and a connecting device 20. The gripping tool 12 can be moved by an actuation system, not shown, for example, a robotic arm. The gripping tool 12 includes, in particular, a gripping head 14 having a face 16, preferably flat. In one embodiment, the head 14 is a cylindrical part with a circular base. The head 14 may be made of a ferromagnetic material. The connecting device 20 is disposed on the head 14 and covers, in particular, the face 16.

[0036] The internal structure of the gripping tool 12 is not shown in the cross-sectional views. In one embodiment, the gripping tool 12 comprises a housing containing a permanent magnet and a actuator, for example a pneumatic or electric actuator, adapted to move the magnet inside the housing to bring the magnet closer to or further from the head 14. Gripping a mechanical part is achieved by bringing the magnet closer to the head. According to In one embodiment, the housing of the gripping tool 12 includes an electromagnet for generating the magnetic field of attraction of the mechanical part to be moved.

[0037] Figure 5 is a partial and schematic perspective view of one embodiment of the connecting device 20. Figure 6 is a partial and schematic top view of the connecting device 20. Figure 7 is a cross-sectional view of Figure 6 along section plane VII-VII.

[0038] The connecting device 20 comprises a membrane 22 delimiting a front face 24 and a rear face 26 opposite the front face 24. In one embodiment, when the connecting device 20 is mounted on the head 14, the front face 24 is substantially flat and the rear face 26 is in physical contact with the face 16 of the head 14. Alternatively, the face 24 is not flat. The face 24 includes, for example, protrusions designed to improve the grip between the connecting device 20 and the workpiece to be moved, particularly during lateral linear movement. The front face 24 is intended to be in contact with the workpiece to be handled by the gripper 10. In one embodiment, the membrane 22 does not have a through-hole. In another embodiment, the thickness of the membrane 22 is between 0.05 mm and 5 mm.

[0039] The connecting device 20 includes an annular portion 28 extending along the periphery of the membrane 22. Preferably, the annular portion 28 extends around the entire periphery of the membrane 22. The annular portion 28 includes an inner side wall 30, an outer side wall 32, and a rear edge 34. In one embodiment, the annular portion 28 projects from the rear face 26 of the membrane 22. Preferably, the connecting device 20 does not include any elements projecting from the front face 24. The rear edge 34 may to correspond to a flat surface. The annular portion 28 has a shape complementary to the head 14. According to one embodiment, when the head 14 corresponds to a cylindrical part with a circular base, the annular portion 28 can be circular. The inner side wall 30 and the outer side wall 32 can then correspond to cylindrical walls with a circular base. Furthermore, the connecting device 20 can then be rotationally symmetrical.

[0040] Generally, the dimensions of the annular portion 28 depend on those of the head 14, and therefore on the dimensions of the parts to be handled. In one embodiment, when the annular portion 28 is circular, it has an internal diameter between 10 mm and 100 mm and an external diameter between 25 mm and 70 mm. In another embodiment, the thickness of the annular portion 28, measured perpendicular to the front face 24, is between 5 mm and 15 mm.

[0041] The connecting device 20 includes means for attaching the connecting device 20 to the head 14 of the gripping tool 12. In one embodiment, the attaching means include a lip 40 projecting towards the head 14 from the inner wall 30 of the annular portion 28, extending from the rear edge 34 of the annular portion 28. The connecting device 20 is attached to the gripping head 14 by deforming the lip 40. In Figure 4, the lip 40 is shown undeformed, thus partially overlapping the head 14. The gripping tool 12 may include a groove 44 at the base of the head into which the lip 40 can penetrate, at least partially. The engagement of the lip 40 in the groove 44 improves the retention of the connecting device 12.

[0042] In the embodiment illustrated in figures 5 and 6, the lip 40 is present over the entire junction between the inner wall 30 and the rear edge 34. As an alternative, the continuous lip 40 can be replaced by several distinct lips, each projecting towards the head 14 from the inner wall 30 of the annular portion 28 in line with the rear edge 34 of the annular portion 28.

[0043] In one embodiment, the connecting device 20 is a single piece. In another embodiment, the connecting device 20 is made of a flexible material. In another embodiment, the Shore A hardness of the material composing the connecting device 20 is between 50 Shore A and 65 Shore A. The Shore A hardness measurement can be carried out according to ISO 48-4:2018. The connecting device 20 can be made of a polymer. The connecting device 20 can be made of polyurethane. In one embodiment, the connecting device 20 is manufactured by molding. In another embodiment, the connecting device 20 is manufactured by 3D printing.

[0044] Figures 8, 9, and 10 are views analogous to Figure 4, illustrating the manipulation of mechanical parts 50, 52, and 54 of different dimensions by the magnetic gripper 10. As illustrated by these figures, the gripper 10 can be used to manipulate a mechanical part 50 whose lateral dimension is less than the lateral dimension of the head 14, a mechanical part 52 whose lateral dimension is slightly greater than the lateral dimension of the head 14 and less than the lateral dimension of the connecting device 12, or a mechanical part 54 whose lateral dimension is greater than the lateral dimension of the head 14 and greater than the lateral dimension of the connecting device 12. The presence of the membrane 22 prevents the part mechanical part 50 to be moved does not come into direct contact with the head, even when the lateral dimension of the mechanical part 50 is less than the lateral dimension of the head 14. In addition, the reduced thickness of the membrane 22 allows the mechanical part 50, 52, 54 to be moved to remain close to the front face 16 of the head 14, where the magnetic field has a maximum intensity outside the gripper 10.

[0045] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will become apparent to them. Finally, the practical implementation of the described embodiments and variations is within the grasp of those skilled in the art, based on the functional indications given above.

Claims

CLAIMS A magnetic gripper connection device (20) comprising a membrane (22) having first and second opposing faces (24, 26), an annular portion (28) projecting from the second face along the periphery of the membrane, and deformable fastening means (40) projecting from the annular portion. A connection device (20) according to claim 1, wherein the membrane (22) and the annular portion (28) form a single piece. A connection device (20) according to claim 1 or 2, wherein the fastening means (40) comprise a deformable lip. A connection device (20) according to any one of claims 1 to 3, wherein the membrane (22) and the annular portion (28) are made of a flexible material. Connection device (20) according to any one of claims 1 to 4, wherein the thickness of the membrane (22) is between 0.05 mm and 5 mm.A connecting device (20) according to any one of claims 1 to 5, wherein the thickness of the annular portion (28) is between 5 mm and 15 mm. A connecting device (20) according to any one of claims 1 to 6, wherein the maximum lateral dimension of the membrane is between 10 mm and 100 mm. A connecting device (20) according to any one of claims 1 to 7, comprising an axis of revolution symmetry. A magnetic gripper (10) comprising a magnetic gripping tool (12) and a connecting device (20) according to any one of claims 1 to 8. A magnetic gripper according to claim 9, wherein the magnetic gripping tool (12) comprises a head (14) having a third face (16), the membrane (22) covering the entire third face, the second face (26) being in physical contact with the third face. A magnetic gripper according to claim 9 or 10, wherein the third face (16) is flat. A magnetic gripper according to any one of claims 9 to 11, comprising a groove (44) into which the deformable fastening means (40) penetrate at least partially.

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