DEVICE FOR GRIPPING PRODUCT LAYERS

Description

TECHNICAL FIELD OF THE INVENTION

[0001] The invention belongs to the technical field of devices and systems applicable to the field of logistics.

[0002] In particular the invention relates to a gripping device that can be mounted on a palletizing or depalletizing robot for gripping layers of products. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] In this field, palletizing or depalletizing systems exist, using a robot to deposit or remove layers of products, notably by clamping or gripping from below or by suction.

[0004] Existing solutions are generally only suitable for certain products and lack effectiveness. In particular, some solutions feature a movable gripping plate within a vacuum chamber; however, the chamber volume is not appropriate for the height of the objects, resulting in ineffective vacuuming. Others systematically require mechanical clamping on the sides, which is unsuitable for fragile objects.

[0005] Some solutions use a support system from below for the objects being grasped, however these systems are often bulky.

[0006] Document US2013 / 236285 presents a gripping device with a suction plate and a side skirt made of flexible material.

[0007] The present invention aims to provide a gripping device suitable for mounting on a palletizing robot and enabling the resolution of at least some of the problems mentioned above. SUMMARY OF THE INVENTION

[0008] To this end, the invention relates to a gripping device intended to be mounted on a palletizing or depalletizing robot for gripping a set of products arranged in at least one layer on a container, said gripping device comprising a frame on which are mounted: a suction plate comprising lateral faces forming support surfaces and a lower face which forms a substantially horizontal plane relative to the ground when the gripping device is mounted on the robot, said suction plate being connected to a first pumping device and having vacuum openings, and being arranged so that its lower face comes into contact with a layer of products by a movement of the gripping device, and a lateral skirt of flexible material forming a band surrounding said lateral faces of the suction plate,

[0009] According to the invention, the skirt is configured to move from a rest position in which it is at a distance from the layer(s) of product to a working position in which it is in contact with the layer(s) of product and the support surfaces of the suction plate and in which it forms with the plane (P) a closed vacuum volume above and on the sides of the layer(s) of product, the suction plate being movable vertically relative to the skirt to adapt the vacuum volume to the height of the layer(s) of product to be grasped by the gripper.

[0010] Adapting the vacuum volume to the objects reduces leakage and maximizes the effect of the vacuum, allowing for better object retention.

[0011] Vacuum holding is a method of holding suitable for all types of objects, especially the most fragile ones that cannot be held by mechanical clamping, such as secondary packaging for dairy products.

[0012] Optionally, the vacuum volume can be adapted to the nature of the products.

[0013] The robot can be multi-articulated, Cartesian or any other system adapted to palletizing or depalletizing that can support the gripper according to the invention.

[0014] The products can be of different kinds, for example cardboard, dairy products or any other product from the agri-food industry that can be transported on a pallet.

[0015] Advantageously, the suction plate can include lateral openings around its perimeter to allow the side skirt to adhere to its support faces by suction in the working position. This provides a better seal of the vacuum volume.

[0016] According to the invention, the gripping device further comprises a clamping device capable of being activated to come into contact with and / or clamp the layer(s) of product(s). This ensures or improves the retention of the products, particularly rigid products.

[0017] Depending on the nature of the products, the clamping device can grip the products when they are rigid or just in contact to promote retention by vacuum. According to the invention, the clamping device comprises four telescopic bars forming a rectangle whose surface area decreases when the clamping device is activated to make contact with the layer of products. This helps to define the vacuum space and increases the effectiveness of product retention. In one embodiment, the skirt comprises four rectangular panels, each positioned on one side of the rectangle defined by the telescopic bars and having a length similar to the maximum length of the telescopic bar positioned on the same side of the rectangle and having a lower edge partially attached to it.

[0018] This facilitates maintenance and increases the lifespan of the skirt as it is better suited to changing sizes of product layers.

[0019] Advantageously, an accumulation device can be arranged between each pair of adjacent telescopic bars, said accumulation device being configured to receive an excess portion of each of the two canvases attached to said pair of telescopic bars when the clamping device is activated to come into contact with the layer(s) of product.

[0020] The accumulation device may have a height at least similar to the height of the canvases.

[0021] This ensures a good seal, which increases the effectiveness of the vacuum. Furthermore, by preventing the folding or creasing of excess fabric, it increases the lifespan of the skirt.

[0022] Advantageously, the gripping device may further include a support platform for the layer(s) of product(s), movable horizontally between a support position in which it is located under the layer(s) of product(s) and a retracted position in which it is away from the products. The products are, for example, held by the suction cup and secured from below by the platform to prevent one or more products from falling.

[0023] Advantageously, the support platform can be formed by a plurality of panels hinged to one another and capable of being deployed under the products in the support position and folded back in the retracted position. This arrangement reduces dead space and the overall system size, resulting in a more compact gripper.

[0024] Advantageously, the platform can be formed from two identical parts, each arranged on one side of the chassis base. This two-part arrangement further reduces the footprint of the gripping device.

[0025] Advantageously, the suction plate may further include suction openings connected to a second pumping device and configured to suction products when the suction plate is in contact position with the layer(s) of product.

[0026] The separate suction openings from the vacuum openings can, for example, be connected to a vacuum pump capable of providing a high flow rate and enabling powerful suction of the products from above.

[0027] The suction openings can, for example, lead into individual suction cups or foam plates arranged at the lower end of the suction plate.

[0028] Advantageously, the gripping device may include at least one contact detector between the suction plate and the products.

[0029] The invention also relates to a palletizing or depalletizing system comprising a robot equipped with a gripping device as described above. BRIEF DESCRIPTION OF THE FIGURES

[0030] Other features and advantages of the invention will become apparent from the following description in relation to the accompanying drawings, given by way of non-limiting examples, in which: [ Fig. 1 [ ] is an overall view of an example of a gripper according to the invention. [ Fig. 2 ] is an exploded view of the gripper of the figure 1 . [ Fig. 3 ] is a bottom view of the gripper of the figure 1 . [ Fig. 4 ] is a perspective view from below showing a support platform in the folded position. Fig. 5[ ] is a perspective view from below showing an example of a two-part support tray in the open position. Fig. 6 ] is a perspective view from below showing an accumulation device according to an embodiment of the invention.

[0031] Unless otherwise specified, the same element appearing on different figures has a unique reference. DETAILED DESCRIPTION

[0032] There figure 1 shows a schematic representation of an example embodiment of a gripper 1 according to the invention. figure 2 is an exploded view of gripper 1 of the figure 1 .

[0033] The gripper 1 can be mounted on a multi-articulated robot or a Cartesian type robot.

[0034] According to the illustrated embodiment, the gripper 1 comprises a frame 2 with a rectangular base 21 and supports 22, 23, 24, 25 that are uprights of the base 21. A system of cross bridges 26, 27 can be attached to the upper ends of the supports 22, 23, 24, 25. A suction plate 3 is connected to this system of bridges by a mechanism that allows vertical movement of the suction plate relative to the frame. Such a mechanism is known per se and will therefore not be described in detail here.

[0035] In the example embodiment, the suction plate 3 is connected to two turbine pumps via tubes 33, 34 and includes downward openings 30 and lateral openings 31.

[0036] Advantageously, the suction plate 3 may further include suction openings 32 visible on the figure 3These suction openings are connected to a vacuum pump 35 to allow for direct suction of the products from above, when the suction plate is in contact with the product layer and the vacuum is activated. This is particularly advantageous for products with a smooth upper surface that allows for suction.

[0037] In the illustrated embodiment, the lower face 38 comprises foam plates 39 into which suction openings 32 open, through which objects can be sucked up.

[0038] According to another embodiment, not illustrated, the suction openings lead into individual suction cups.

[0039] As shown by the figure 2 , a lateral skirt 4 made of flexible material forming a band surrounding the lateral faces of the suction plate 3.

[0040] According to the example of implementation illustrated in figures 2 And 6The skirt 4 comprises four rectangular canvases 41, 42, 43, 44. The lower edge of each canvas is partially attached to a telescopic bar 61, 62, 63, 64 of a clamping device 6 arranged in the base 21 of the frame. The attachment is on the fixed portion of the telescopic bar. The canvas is not attached to the slide 71, 72.

[0041] As depicted on the figure 3 , the clamping device 6 is in a configuration where the telescopic bars 61, 62, 63, 64 have their maximum lengths.

[0042] In the example implementation shown to Figures 1 And 3 , the top side and the other sides are also fixed by known means so that each canvas retains the shape of a rectangle.

[0043] Furthermore, as can be seen in particular on the Figures 1 And 6, an accumulation device 7 is arranged between each pair of adjacent telescopic bars 61, 62. The accumulation device 7 is configured to receive the excess part of each of the two canvases 41, 42 attached to the pair of telescopic bars 61, 62 when the clamping device is activated to come into contact with the layer(s) of product.

[0044] THE figures 4 And 5 show an optional 5, 5' support tray for the product layer(s) in the support position in which it is deployed under the product layer(s).

[0045] According to the example shown, the support platform is formed of two parts, each comprising a plurality of panels 51, 52, 53, 51', 52', 53' hinged to each other and capable of being deployed under the products in the support position and folded back into the folded position as in the figure 4 .

[0046] To load one or more layer(s) of product by the gripping device 1 according to the invention, the following steps are performed by the palletizing / depalletizing system comprising the device 1: The robot, carrying a gripping device 1, moves the device towards the pallet on which the products are loaded. With the suction plate 3 in a lower position at the base 21 of the chassis, the device 1 is moved until contact occurs between the underside of the plate 3 and the upper surface of the products. A 3D camera 9 can be used to center the gripper during this descent. The contact can be detected by infrared sensors located on the underside of the chassis and / or a motion detector on the upper side of the chassis. The robot continues to descend, which induces a relative displacement of the suction plate 3 with respect to the skirt. This displacement is a predetermined vertical distance relative to the thickness of the layer(s) of product to be gripped.Depending on the nature of the products, the clamping device 6 can be activated to make contact with the products only or to exert a clamping force on them. When the telescopic bars 61, 62, 63, and 64 move into contact with the products, the skirt panels are also moved until contact occurs between the skirt and the lateral surfaces 30 of the plate 3, as well as with the products. When the panels forming the telescopic skirt 4 move into contact with the products, the excess material of each panel 41, 42, 43, and 44 accumulates on each side in an accumulation device 7, so that in each accumulation device, the excess material of two panels intersects, creating a seal in the vacuum chamber. The turbines can be activated to create a vacuum in the chamber and secure the skirt to the lateral surfaces of the plate through the openings 31.This vacuum may be sufficient in some cases to grasp the layer of products. Suction through the suction openings 32 can optionally be activated by activating the vacuum pump. The support tray can also be deployed to pass under the products and further secure the movement of objects grasped by device 1.

Claims

1. Gripping device (1), intended to be mounted on a palletizing or depalletizing robot and intended for gripping a set of products arranged in at least one layer on a container, said gripping device (1) comprising a frame (2) on which the following are mounted: - a suction plate (3) comprising side faces forming bearing surfaces and a lower face forming a substantially horizontal plane (P) when the gripping device is mounted on the robot, said suction plate being connected to a first pumping device and having vacuum openings (30), and being arranged so that the bottom face of the suction plate comes into contact with a product layer by means of a movement of the gripping device, and - a side skirt (4) made of flexible material forming a strip surrounding said side faces of the suction plate (3), the skirt (4) being designed to go from a rest position in which it is spaced apart from the product layer(s) to a working position in which it is in contact with the product layer(s) and the bearing surfaces of the suction plate and in which the skirt (4), together with the plane (P), forms a closed vacuum volume above and at the sides of the product layer(s), the suction plate (3) being vertically movable relative to the skirt (4) in order to adapt the vacuum volume to the height of the product layer(s) to be grasped by the gripping device, the gripping device further comprising a clamping device (6) which is capable of being activated to come into contact and / or to clamp the product layer(s), characterized in that said clamping device (6) comprises four telescopic bars (61, 62, 63, 64) forming a rectangle, the surface of which decreases when the clamping device (6) is activated to come into contact with the product layer(s).

2. Gripping device (1) according to claim 1, wherein the suction plate (3) comprises side openings (31) on its contour for adhering the side skirt (4) by suction to the bearing faces of the suction plate in the working position.

3. Gripping device (1) according to any of the preceding claims, wherein the skirt (4) comprises four rectangular webs (41, 42, 43, 44), each being arranged on a side of the rectangle defined by the telescopic bars (61, 62, 63, 64) and having a length similar to the maximum length of the telescopic bar (61, 62, 63, 64) arranged on the same side of the rectangle and having a lower side partially attached to the telescopic bar.

4. Device (1) according to the preceding claim, wherein a gathering device (7) is arranged between each pair of adjacent telescopic bars (61, 62), said gathering device (7) being designed to receive an excess portion of each of the two webs attached to said pair of telescopic bars when the clamping device is activated to come into contact with the product layer(s).

5. Gripping device (1) according to any of the preceding claims, further comprising a support tray (5, 5') for supporting the product layer(s), which tray is movable horizontally between a support position in which it is located under the product layer(s) and a folded position in which it is away from the products.

6. Gripping device (1) according to the preceding claim, wherein the support tray (5, 5') is formed by a plurality of panels (51, 52, 53, 51', 52', 53') articulated relative to one another and capable of being deployed under the products in the support position and of being folded in the folded position.

7. Gripping device according to any of the preceding claims, wherein the suction plate (3) further comprises suction openings (32) connected to a second pumping device and designed to suck products when the suction plate is in a position of contact with the product layer(s).

8. Palletizing or depalletizing system comprising a robot provided with a gripping device according to any of the preceding claims.