Gripper for gripping a product, in particular a food product

Abstract

The invention relates to a gripper (1) for gripping a product, in particular a food product, comprising a base (30) and a stop element (40) for holding, guiding, and / or positioning the product, wherein the stop element (40) comprises a backbone (R) and a rib (42) and is connected to the base (30), the rib (42) has a free end (421) and a connecting end (422), and the connecting end (422) of the rib is connected to the backbone (R). The product can be placed on the rib (42) in order to be held, guided, and / or positioned.

Description

[0001] DESCRIPTION

[0002] title

[0003] Gripper for gripping a product, especially a food product

[0004] State of the art

[0005] The invention relates to a gripper for grasping products, in particular food products, for example salmon or salmon fillets. Such grippers are usually used in devices that have a conveying unit for transporting food products along a main conveying direction and a packaging and / or food processing unit downstream of the conveying unit in the main conveying direction. In this respect, such grippers can be used, for example, to transport food products from the conveying unit to the packaging unit.

[0006] To increase the level of automation, robotic systems (e.g., delta-pick robots, multi-axis robots, SCARA robots, etc.) are frequently used for loading packaging units. These systems can be equipped with a gripper of the type mentioned above. The product stream arriving from the upstream process step can be gripped by the robotic system and transported into the packaging unit or into a container. The grippers that can be attached to the robotic system can vary considerably in their design, depending particularly on the product. During transport, the food products must be securely held or fixed within the gripper. For example, so-called hold-down devices can be used within the gripper for this purpose. Such a hold-down device is disclosed, for example, in DE 10 2015 122 392 A1.It may be necessary not only to secure the food products within the gripper, but also to position them correctly to prevent damage. In particular, food products protruding beyond certain positional limits, such as the gripper limits, can lead to damage during transport.

[0007] Disclosure of the invention

[0008] The object of the present invention is therefore to provide a simple and efficient solution for positioning food products within the gripper. This object is achieved by a gripper for grasping a product, in particular a food product, comprising a base and a stop element for holding, guiding, and / or positioning the product. The stop element comprises a backbone and a rib and is connected to the base. The rib has a free end and a connecting end and is connected to the backbone at its connecting end. The product can be arranged on the rib for holding, guiding, and / or positioning. Preferably, the stop element comprises two ribs. Preferably, the ribs are arranged coplanarly. Preferably, the product can be arranged between the two ribs.

[0009] The gripper according to the invention has the advantage that the stop element provides a simple solution for positioning the food product within the gripper. In particular, the food product can be centered by means of the ribs. Furthermore, the ribs, especially the free ends of the ribs, can be used to fix and guide the food product. Since the ribs each have a free end, i.e., are designed as cantilevers, they can also be spring-loaded, at least to a certain extent. This allows the food product to be fixed and positioned gently. Damage to the food product can be easily avoided or at least reduced by means of the stop element, especially in conjunction with a hold-down device.

[0010] According to a preferred embodiment of the present invention, the ribs are arc-shaped or comprise an arc-shaped section. It is conceivable that the ribs are multisectional. In other words, each rib can comprise several segments. In particular, a straight segment can be formed at the free end of each rib. The ribs can be thin-walled and, for sufficient strength, incorporate stiffening elements formed integrally with the ribs. In particular, a rib can have an elongated stiffening element extending along one of its lengths. The elongated stiffening element can be located on the side of the rib facing the base and thus away from the food product. The thin walls result in material and cost savings.According to a further preferred embodiment of the present invention, the ribs are arranged in a plane that is perpendicular to an axis of extension of the spine. The two ribs in a plane can be referred to as a rib pair. Furthermore, the plane in which the two ribs are arranged can be referred to as the rib plane.

[0011] In an advantageous embodiment of the invention, the ribs are symmetrical with respect to an axis of symmetry, wherein the axis of symmetry is in particular arranged perpendicular to an axis of extension of the spine. Alternatively, the two ribs of a plane, i.e., of a pair of ribs, can be symmetrical with respect to a plane of symmetry, wherein the plane of symmetry is in particular arranged perpendicular to an axis of extension of the spine.

[0012] According to a preferred embodiment of the present invention, the ribs each have a stop surface on a side facing away from the base and towards the product. The stop surfaces are formed at the respective free end of the associated rib, and the product can be held and / or positioned, in particular centered, by means of the stop surfaces. Centering within the meaning of the invention means, in particular, compressing the product perpendicular to a longitudinal axis of the product, the longitudinal axis being arranged parallel to the axis of extension of the backbone. The stop surfaces of a pair of ribs can be symmetrical with respect to a plane of symmetry, the plane of symmetry being arranged perpendicular to an axis of extension of the backbone. Furthermore, the stop surfaces can be flat, i.e., two-dimensional. However, it is also conceivable that the stop surfaces are bent or curved.Furthermore, the respective contact surfaces can comprise multiple surface sections and be three-dimensional. For example, a contact surface can comprise two flat surface sections, with an angle formed between them. Ribs can be provided both by means of multiple surface sections per contact surface and by means of curved contact surfaces, enabling better, more form-fitting holding and positioning of the product. The contact surfaces can, in particular, extend over several segments of the corresponding rib. For example, a rib can have a first straight segment at its free end and a second curved segment, with the second curved segment being located partly at the free end and partly between the free end and the backbone of the contact element.Especially with food products such as fish, meat or cheese, which are flexible in their shape and therefore when positioning / centering, it can be advantageous to support and position the food product with the largest possible contact surface over the largest possible number of segments, since the food product is thus supported in a greater number of spatial directions and can be held, guided and positioned better and more safely overall.

[0013] According to an advantageous embodiment of the present invention, four, six, eight, ten, twelve, fourteen, or sixteen ribs are provided, with each pair of ribs arranged coplanarly, each pair being arranged in a different plane. A plane in which two ribs are arranged can be referred to as a rib plane. Preferably, all rib planes are arranged parallel to one another. In other words, all rib pairs are arranged perpendicular to one another. Furthermore, all ribs of all rib pairs are geometrically identical. For example, all ribs have the same length, the same width, the same cross-section, the same curvature, etc. In addition, all rib pairs are flush with one another parallel to the axis of extension of the spine. In other words, the rib pairs are arranged without offset from one another in a direction perpendicular to the axis of extension.Rather, the projection of one pair of ribs parallel to the axis of extension yields the position of all other pairs of ribs.

[0014] In a preferred embodiment of the invention, each plane is arranged perpendicular to the spine, with all planes being uniformly spaced apart. A rib of one plane is connected to another rib of an adjacent plane by means of a stabilizing web, each stabilizing web being arranged perpendicular to the ribs. The stabilizing webs can be formed integrally with the stop element. The stabilizing webs increase the strength and, consequently, the dimensional stability of the stop element. In other words, the stabilizing webs increase the stiffness of the stop element, particularly parallel to the axis of extension E.

[0015] In a preferred embodiment, the stop element is manufactured additively, i.e., using a 3D printing process. 3D printing processes enable the simple production of complex geometries, such as curved ribs. Unlike subtractive processes, where material is removed, for example, by milling, 3D printing processes use only the material required for the stop element. This reduces waste and saves on material costs.

[0016] According to a preferred embodiment of the present invention, the stop element comprises a spring element for holding the product down. The spring element has a connecting section with a first end and a second end, and a holding section, wherein the connecting section is connected to the stop element at its first end and to the holding section at its second end. The spring element is spring-like and / or deformable relative to the stop element. The spring element can be integrally connected to the stop element, and in particular, it can be additively manufactured with the stop element. The spring element, which acts as a hold-down, is relatively lightweight. This allows the drive power of the gripper to be advantageously reduced. In particular, the spring element can be made of a relatively low-density plastic, i.e.,The gripper is made of a relatively lightweight plastic. Furthermore, for efficient and secure product holding, it does not require a multi-part spring element, elastomers attached to the spring element, or additional components to prevent deformation and / or damage to the product. Rather, the spring element itself provides the advantage of springability and / or deformability. Springability or deformability, as defined in the invention, refers in particular to the advantageous elastic deformability of the spring element, such that no lasting plastic changes are caused by static or quasi-static impact on the product.

[0017] An advantageous embodiment of the invention provides that the spring element is arranged between a first plane and a second plane, wherein a first pair of ribs is arranged in the first plane and a further pair of ribs is arranged in the second plane. In other words, the spring element – ​​preferably two spring elements arranged coplanarly and spaced equally apart from the first and second planes respectively – can be arranged between the first and second planes.

[0018] Preferably, the stop element comprises several connecting elements for connecting the stop element to the base, wherein the connecting elements are formed on the backbone of the stop element and extend on a side of the backbone facing away from the ribs. By means of the connecting elements, which are preferably formed integrally with the stop element – ​​and manufactured, for example, and in particular, by additive manufacturing – the stop element can be detachably connected to the base or the gripper. Furthermore, in all conceivable embodiments of the invention, the stop element, the ribs, and the one or more spring elements preferably have smooth surfaces. The advantage of smooth surfaces lies in reduced cleaning effort, for example, during maintenance, repair, or other work.

[0019] Repair work, etc. Product residue adhering to the hold-down device can be avoided or at least reduced by using smooth surfaces. Consequently, the handling of subsequent products can be improved, and unwanted product residues that could enter packaging can be avoided or reduced. To facilitate or improve cleaning, the stop element and spring elements can be made of corrosion-resistant materials that can be easily cleaned with water, e.g., corrosion-resistant steel or polymer materials such as POM, PA, PETG, HDPE, Teflon, etc., or other types of – preferably rigid – plastics.

[0020] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of preferred embodiments with reference to the drawings. The drawings merely illustrate exemplary embodiments of the invention, which do not limit the essential concept of the invention.

[0021] Brief description of the drawings

[0022] Figure 1 schematically shows in a perspective view a gripper according to the invention for gripping a food product in an open state, wherein the gripper has a base, a stop element and four spring elements.

[0023] Figure 2 shows the gripper from Figure 1 in a closed state in the same perspective view.

[0024] Figure 3a shows the gripper from Figures 1 and 2 in a side view.

[0025] Figure 3b shows the gripper shown in a side view from Figure 3a in a partial sectional view according to a section plane AA shown in Figure 3a.

[0026] Figure 3c shows the gripper shown in a side view from Figure 3a in a partial sectional view according to a section plane BB shown in Figure 3a.

[0027] Figure 4 schematically shows in a perspective view the

[0028] Stop element according to the gripper according to the invention from figures 1 to 3c.

[0029] Figure 5 schematically shows a perspective view of a

[0030] Detailed view of the stop element shown in Figure 4 in a partial sectional view.

[0031] Figure 6 schematically shows in a side view the device shown in Figure 5.

[0032] Stop element, wherein a food product is held down by two spring elements integrally connected to the stop element.

[0033] Figure 7 schematically shows in a side view the device shown in Figure 5.

[0034] Stop element, wherein a food product is positioned by the stop element.

[0035] Embodiments of the invention

[0036] In the various figures, identical parts are always marked with the same reference symbols and are therefore usually only named or mentioned once.

[0037] Figure 1 schematically depicts a perspective view of a gripper 1 according to the invention for gripping a food product 2 in an open state, wherein the gripper 1 has a base 30, a stop element 40, and four spring elements 10. The food product 2 (see Figures 6 and 7) and one of the four spring elements 10 are not shown or visible in Figure 1. The spring elements 10 can hold the food product 2 down in a way that secures it and simultaneously position it.

[0038] Each of the spring elements 10 comprises a connecting section 12 with a first end 121 and a second end 122, and a hold-down section 14, the exact construction of the spring elements 10 being described and illustrated in more detail below. Each connecting section 12 is indirectly connected at its first (as shown in Figure 1, upper) end 121 to the base 30 or the gripper 1 by means of the stop element 40. Furthermore, each spring element 10 is connected at its second end 122 to the hold-down section 14. All spring elements 10 are designed to be springable or deformable relative to the rest of the gripper 1. As a result of the springiness or deformability of the spring elements 10, the risk of damage to the food product 2 can be at least reduced, and ideally completely avoided.

[0039] The base 30 comprises two base segments 301, 302 that are movable linearly relative to and away from each other; a first base segment 301 and a second base segment 302. The movement is pneumatically actuated by means of two guide rods F, but can also be electrically, electromechanically, hydraulically, or by means of other means, media, and / or methods. On the two base segments 301, 302, paddles 50 are formed for lifting and lowering the food product 2. The paddles 50 have a reduction in wall thickness or cross-sectional narrowing at their respective leading edges to facilitate gripping under the food product 2, which is arranged on a surface (not shown), for example, and in particular, on a conveyor belt. To lift the food product 2, for example, salmon or...To lift a salmon fillet as evenly as possible, eight evenly spaced paddles 50 are provided on each of the two base segments 301 and 302. The paddles 50 extend, in particular, perpendicular to a transport direction T of the food product 2, wherein the transport direction T is arranged parallel to an extension axis E of the backbone R of the stop element 40.

[0040] The gripper 1 also has a robot interface 20 formed at its base 30 for a robot (not shown) for spatially moving the gripper 1. Furthermore, supply lines for compressed air are provided at the robot interface 20.

[0041] Figure 2 shows the gripper 1 from Figure 1 in a closed state, in the same perspective view. For this, the first and second base segments 301, 302 were moved towards each other. Consequently, the food product 2 is slightly lifted by the scoops 50. Simultaneously, the food product 2 is held down and fixed by the spring elements 10, thus making it ready for transport to a packaging machine (not shown). The stop element 40, resembling a ribcage (see also Figure 4), ensures improved positioning, in particular centering, of the food product 2 by means of several stop surfaces 424. The stop element 40, its structure, and function are described in more detail below.

[0042] Figure 3a shows the gripper 1 from Figures 1 and 2 in a side view.

[0043] Figure 3b shows the gripper 1 from Figure 3a, depicted in a side view, in a partial sectional view along a section plane AA shown in Figure 3a. The spring elements 10 each have a curved connecting section 12 and a curved hold-down section 14. The two hold-down sections 14 visible in Figure 3b each comprise a holding surface H. The holding surfaces H themselves are also curved. The holding surfaces H are formed on a side of the hold-down section 14 facing away from the connecting section 12 and the base 30. In other words, the holding surfaces H face the scoops 50 and the food product 2, respectively.

[0044] The hold-down sections 14 each comprise a first free end 141, wherein the first free ends 141 are arranged on opposite sides of the hold-down section 14. Furthermore, the hold-down sections 14 each comprise a second free end 142. The two second free ends 142 are formed on the respective opposite sides of the hold-down sections 14. A small gap is formed between the two second free ends 142. In another embodiment of the invention, it would be possible for the two second free ends 142 to be fused or grown together. In other words, it is conceivable that the two connecting sections 12 are connected by a single hold-down section 14.The connection between a connecting section 12 and a hold-down section 14 is in every case made by means of the second end 122 of the connecting section 12 of the respective spring element 10. According to the embodiments of the spring elements 10 shown in the figures, the connection between a connecting section 12 and a hold-down section 14 is made at a central section 143 of the hold-down section 14. The respective central section 143 is arranged exactly between the first free end 141 and the second free end 142 of the hold-down section 14.

[0045] The two spring elements 10 shown in Figure 3b are arranged coplanarly. Also arranged coplanarly are two ribs 42 visible in Figure 3b, which are integrally connected to the stop element 40. However, the ribs 42 are arranged in a different plane than the two spring elements 10, with both planes – the plane of the ribs and that of the spring elements – being parallel to each other.

[0046] Figure 3c shows the gripper 1 from Figure 3a, shown in a side view, in a partial sectional view according to a section plane BB shown in Figure 3a, which is arranged parallel to the section plane AA shown in Figure 3b.

[0047] Figure 4 schematically shows, in a perspective view, the stop element 40 according to the gripper 1 from Figures 1 to 3c. The stop element 40 and the four spring elements 10 are additively manufactured, i.e., produced using a 3D printing process. They are made of the same material. The stop element 40 comprises a total of sixteen ribs 42, configured as eight rib pairs P. The two ribs 42 of a rib pair P are arranged coplanarly in a rib plane, with all rib planes, i.e., all eight rib planes, being equidistant. In other words, the distance between two ribs 42 of different rib planes is always the same, with the distances being measured parallel to an axis of extension E of the spine R. A stabilizing web 44 is formed between each pair of adjacent ribs 42 of different rib planes.The stabilizing webs 44 increase the strength and, consequently, the dimensional stability of the stop element 40. In other words, the stabilizing webs 44 increase the stiffness of the stop element 40, particularly parallel to the axis of extension E. Furthermore, the axis of extension E is arranged perpendicular to the rib planes.

[0048] The stop element 40 comprises two connecting links 60 for connecting the stop element 40 to the base 3. The connecting links 60 are formed on the backbone R of the stop element 40 and extend on a side of the backbone R facing away from the ribs 42. In other words, the stop element 40 can be suspended from the base 30. With an increasing number of connecting links 60, deformation of the stop element 40 under its own weight is more effectively prevented or at least reduced.

[0049] Figure 5 schematically shows a detailed perspective view of the stop element 40 shown in Figure 4, in a partial sectional view. The section plane shown in Figure 5 passes through the stabilizing webs 44, which is why these are also shown cut through. The two coplanar spring elements 10 are arranged in a plane that lies between a first rib plane and a second rib plane. The springiness or deformability of the two spring elements 10 is illustrated in Figure 5 by the two curved arrows.

[0050] Figure 6 schematically shows a side view of the stop element 40 shown in Figure 5, in which a food product 2 is held down by two spring elements 10 integrally connected to the stop element 40. The two spring elements 10 are symmetrical with respect to an axis of symmetry S. The axis of symmetry S is perpendicular to the axis of extension E and parallel to the rib planes. The food product 2 has an elliptical cross-section. The shape of the holding sections 14 is adapted to the outer contour of the food product 2 in order to maximize the contact area between the respective holding sections 14 on the one hand and the food product 2 on the other. A total force G per spring element 10, as exerted on the food product 2 for holding and positioning, is represented by a corresponding force vector in Figure 6.Both total forces G each have a force component parallel to the axis of symmetry S and one perpendicular to the axis of symmetry S. The component perpendicular to the axis of symmetry S can be called the centering force, while the component parallel to the axis of symmetry S can be called the holding force.

[0051] Figure 7 schematically shows a side view of the stop element 40 shown in Figure 5, with a food product 2 being positioned by the stop element 40. Each rib 42 has a free end 421 and a connecting end 422. At their respective connecting ends 422, the ribs 42 are connected to the backbone R of the stop element 40. The food product 2 is arranged between the ribs 42 of a plane or a pair of ribs P and can thus be held, guided, and / or positioned by the ribs 42. In the embodiments shown in the figures, the inner distance between the ribs 42 of each pair of ribs P is constant. On a side facing away from the base 30 and towards the food product 2, each rib has a stop surface 424, with the stop surfaces 424 being formed at the respective free end 421 of the associated rib 42.The food product 2 is held, guided and / or positioned, in particular centered, by means of the stop surfaces 424.

[0052] Figure 7 depicts a different plane than the one shown in Figure 6. Since a food product 2, in particular salmon or salmon fillet, can have a variable cross-section and thus a variable width B along its length, contact between the food product 2 and the contact surfaces 424 is not possible along the entire length of the food product 2. (List of reference symbols)

[0053] 1 gripper

[0054] 2 Food product

[0055] 10 spring element

[0056] 12 Connecting section

[0057] 14 Hold-down section

[0058] 20 Robot interface

[0059] 30 Base of the gripper

[0060] 40 Stop element

[0061] 42nd rib

[0062] 44 Stabilizing bridge

[0063] 50 shovels

[0064] 60 Connecting link

[0065] 121 First end of the connecting section

[0066] 122 Second end of the connecting section

[0067] 141 First free end of the hold-down section

[0068] 142 Second free end of the hold-down section

[0069] 143 Middle section of the hold-down section

[0070] 301 First Base Segment

[0071] 302 Second Base Segment

[0072] 421 Free end of a rib

[0073] 422 End of rib connection

[0074] 424 Stop surface

[0075] B Width of the food product

[0076] E Extension axis of the spine

[0077] F Guide rod

[0078] G Total force

[0079] H holding surface

[0080] P rib pair

[0081] R Backbone of the stop element S Axis of symmetry

Claims

PATENT CLAIMS 1. Gripper (1) for gripping a product, in particular a food product, comprising a base (30) and a stop element (40) for holding, guiding and / or positioning the product, wherein the stop element (40) comprises a backbone (R) and a rib (42) and is connected to the base (30), wherein the rib (42) has a free end (421) and a connecting end (422) and is connected to the backbone (R) at its connecting end (422), wherein the product can be arranged on the rib (42) for holding, guiding and / or positioning.

2. Gripper (1) according to claim 1, wherein the ribs (42) are arc-shaped or comprise an arc-shaped section.

3. Gripper (1) according to claim 1 or 2, wherein the ribs (42) are arranged in a plane that is perpendicular to an extension axis (E) of the backbone (R).

4. Gripper (1) according to one of the preceding claims, wherein the ribs (42) are symmetrical with respect to an axis of symmetry (S), wherein the axis of symmetry (S) is in particular arranged perpendicular to an extension axis (E) of the backbone (R).

5. Gripper (1) according to one of the preceding claims, wherein the ribs (42) each have a stop surface (424) on a side facing away from the base (30) and towards the product, wherein the stop surfaces (424) are formed at the respective free end (421) of the associated rib (42), wherein the product can be held and / or positioned, in particular centered, by means of the stop surfaces (424).

6. Gripper (1) according to one of the preceding claims, characterized by four, six, eight, ten, twelve, fourteen or sixteen ribs (42), wherein two ribs (42) are arranged coplanarly as a rib pair (P), each rib pair (P) being arranged in a different plane.

7. Gripper (1) according to claim 6, wherein each plane is arranged perpendicular to the backbone (R), wherein all planes are uniformly spaced apart, wherein a rib (42) of a plane is connected to another rib (42) of an adjacent plane by means of a stabilizing web (44) is connected, wherein each stabilizing web (44) is arranged perpendicular to the ribs (42).

8. Gripper (1) according to one of the preceding claims, wherein the stop element (40) is manufactured additively or in a 3D printing process.

9. Gripper (1) according to one of the preceding claims, wherein the stop element (40) has a spring element (10) for holding down the product, wherein the spring element (10) has a connecting section (12) with a first end (121) and a second end (122), and a holding section (14), wherein the connecting section (12) is connected at its first end (121) to the stop element (40) and at its second end (122) to the holding section (14), wherein the spring element (10) is designed to be springable and / or deformable relative to the stop element (40).

10. Gripper according to claim 9, wherein the spring element (10) is arranged between a first plane and a second plane, wherein a first pair of ribs (P) is arranged in the first plane and a further pair of ribs (P) is arranged in the second plane.

11. Gripper (1) according to one of the preceding claims, wherein the stop element (40) comprises several connecting members (50) for connecting the stop element (40) to the base (30), wherein the connecting members (60) are formed on the backbone (R) of the stop element (40), wherein the connecting members (50) extend on a side of the backbone (R) facing away from the ribs (42).

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