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, having a spring element (10) for holding down and positioning the product, wherein the spring element (10) has a connecting portion (12), which has a first end (121) and a second end (122), and a holding-down portion (14). The first end (121) of the connecting portion (12) is connected to the gripper (1) and the second end (122) thereof is connected to the holding-down portion (14), and the spring element (10) is designed to be resilient and / or deformable (1).

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, particularly depending on the product. During transport, the food products must be well-positioned and securely held 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.In the case of the hold-down device according to the aforementioned document, the product is secured by the hold-down device's own weight. In other words, the hold-down device must have a considerable mass, which can lead to deformation or damage to the products. Furthermore, increased weight can increase the drive power of the gripper, as a larger mass has to be moved. To at least partially solve the problem of potential product damage, DE 102015 122 392 A1 discloses that the hold-down device can have an elastically deformable element or area, or be acted upon by means of an elastic element, so that a comparatively small restoring force is effective in addition to the weight of the hold-down device.However, the latter designs significantly increase the complexity of the gripper, as they involve additional components or different materials and can also drive up costs.

[0007] Disclosure of the invention

[0008] The object of the present invention is therefore to avoid, in whole or in part, the disadvantages mentioned in connection with the prior art and to provide an optimized gripper.

[0009] The object of the present invention is achieved by a gripper for gripping a product, in particular a food product, with a spring element for holding down and positioning the product, wherein 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 at its first end to the gripper and at its second end to the holding section, wherein the spring element is designed to be spring-like and / or deformable relative to the gripper.

[0010] The gripper according to the invention has the advantage over the prior art that the spring element, which acts as a hold-down device, 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., a relatively lightweight plastic. Furthermore, the gripper according to the invention does not require a multi-part spring element, in particular no elastomers arranged on the spring element, or additional components to prevent deformation and / or damage to the products. Rather, the advantage of the spring element according to the invention arises from its inherent spring-like and / or deformable properties.In summary, this provides an optimized, simple, and easy-to-manufacture solution without increasing the costs of manufacturing or operating a gripper. "Springable" or "deformable" in the context of the invention refers in particular to an advantageous elastic deformability of the spring element, such that no lasting plastic changes to the spring element are caused by static or quasi-static loading of a product.

[0011] According to a preferred embodiment of the present invention, the spring element is curved or has a curved section. In particular, the connecting section and / or the hold-down section can be curved or have a curved section or segment. It is also conceivable that the connecting section and the hold-down section are straight, with a curved transition section formed between the connecting section and the hold-down section, so that the spring element as a whole comprises a curved section. Due to the curved shape, purely structural features of the spring element allow for relative movement of several sections of the spring element, for example, the connecting section relative to the hold-down section.This allows the spring element itself to be springable and / or elastically deformable without having to be made of an elastomer or requiring an additional elastomer. Furthermore, the fact that multiple materials do not need to be used offers the advantage that the spring element can be manufactured with relatively thin walls, resulting in a further reduction in mass and weight.

[0012] According to a further preferred embodiment of the present invention, the retaining section has a retaining surface that is curved or has a curved section, wherein the retaining surface is formed on a side of the retaining section facing away from the connecting section. A curved retaining surface is particularly advantageous for fish and meat products, which may have an elliptical cross-section and / or a curved contour or outer shape, since force can be exerted on the product over a large area by means of the spring element or the retaining section, thereby distributing the tension (or pressure) acting on the product more effectively and evenly, and thus reducing it.In other words, the connection section can be configured in such a way that it optimally adapts to the shape of the product, which, as a result of the pressure reduction on the product, reduces the risk of product deformation and damage.

[0013] In an advantageous embodiment of the invention, the hold-down section comprises a first free end, a second free end, and a central section equidistant from both the first and second free ends, with the connecting section being attached to the hold-down section at the central section. In other words, the connecting section can be attached to the hold-down section along a central length of the hold-down section. Preferably, the connecting section and the hold-down section are integrally joined. In other words, the connecting section and the hold-down section can be made of the same material.

[0014] According to an advantageous embodiment of the present invention, several spring elements are provided, wherein two spring elements are configured coplanarly. Spring elements can, in particular, be configured in pairs within a single plane. In this way, the product can be loaded evenly from two sides and thereby held down or fixed. Furthermore, by arranging the spring elements in pairs, the pressure on the product can be further reduced due to an increase in the cumulative holding area or total holding area, thereby decreasing the risk of deformation and damage.

[0015] According to a preferred embodiment of the present invention, two spring elements are arranged in a first plane, and two further spring elements are arranged in a second plane that is different from the first plane. Preferably, the first and second planes are arranged parallel to each other. With a total of four spring elements, arranged in pairs in two different, preferably parallel, planes, the product, for example, a salmon fillet, can be held down and fixed more evenly along its length. This optimizes the holding process. It is conceivable that the product is held down and thus fixed by two further coplanar spring elements in a third plane. A fourth and fifth plane, each containing two further spring elements, are also conceivable.

[0016] Preferably, two spring elements arranged in one plane are symmetrical to each other. In other words, both the respective connecting sections and the respective holding sections of the two spring elements can be symmetrical to each other. In all embodiments of the invention with two symmetrical spring elements, the two spring elements can be arranged, aligned, or configured such that each spring element exerts a total force on the product, which has both a centering force and a holding force as force vector components. The centering force is exerted, as it were, to position and hold the product, while the holding force is suitable for pressing the product onto a surface, in particular against a conveyor belt.The respective centering forces of the two spring elements, which are arranged particularly parallel to the product base, cancel each other out and in turn fix the product in place.

[0017] In an alternative embodiment of the invention, the spring element according to the invention can have two connecting sections and a retaining section, wherein the respective second ends of the connecting sections are connected to the retaining section. In other words, two spring elements can be fused into a single spring element by means of the respective first ends of the retaining sections. A third spring element is also conceivable, which is coplanar with the other two coplanar spring elements, wherein two of the three spring elements are arranged as lateral spring elements and the third spring element is arranged centrally between the two lateral spring elements, wherein the third centrally arranged spring element is, in particular, arranged on an axis of symmetry of the spring element arrangement. In this way, an optimized fixation of the product can be achieved.

[0018] A preferred embodiment of the present invention provides a base and a stop element for holding, guiding, and / or positioning the product. The stop element comprises a backbone and two coplanarly arranged ribs and is connected to the base. Each rib has a free end and a connecting end and is connected to the backbone at its connecting end. The product can be arranged between the ribs for holding, guiding, and / or positioning. The stop element can be used, in particular, to optimize the lateral guidance of the product, for example, by means of a stop surface formed on each rib. Preferably, the one or more spring elements are formed integrally with the stop element. The base can be formed in two parts and comprise a first base segment and a second base segment, the two base segments being movable towards and away from each other.Both base segments can be fitted with scoops for lifting the food product, for example, eight scoops per base segment. The scoops can extend parallel to a plane in which one or two spring elements are arranged. It is particularly conceivable that, for example, two scoops with two spring elements are arranged coplanarly. The ribs can be thin-walled and incorporate stiffening elements integrally with the ribs to ensure sufficient strength. In particular, a rib can have an elongated stiffening element extending along its length. This 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 an advantageous embodiment of the invention, one spring element or two coplanar spring elements are 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 this way, the one spring element or the two coplanar spring elements can project through both planes of the rib pairs and advantageously hold the product down.

[0019] In a preferred embodiment of the present invention, the spring element, or the spring element and the stop element, are manufactured additively or using a 3D printing process. 3D printing processes enable the simple production of complex geometries, such as curved ribs of the stop element. 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.

[0020] In all conceivable embodiments of the invention, bumps or protrusions can be formed on the hold-down sections, particularly on the holding surfaces of the spring element and / or on the stop surfaces of the stop element, to improve grip or increase friction between the spring element and the product. Smooth surfaces are also conceivable. The advantage of smooth surfaces lies in reduced cleaning effort. Adhesion of product residues to the hold-down can be avoided or at least reduced by means of 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.,...made of corrosion-resistant steel or polymer materials such as POM, PA, PETG, PEHD, Teflon etc. or other types of - preferably rigid - plastics.

[0021] Further details, features, and advantages of the invention will become apparent from the drawings and from the following description of a preferred embodiment with reference to the drawings. The drawings merely illustrate an exemplary embodiment of the invention, which does not limit the essential inventive concept. 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 gripper 1 or the base 30 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 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, 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 of the invention 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 uniformly spaced. 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 backbone R. A stabilizing web 44 is formed between each pair of adjacent ribs 42.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.

[0053] Reference symbol list

[0054] 1 gripper

[0055] 2 Food product

[0056] 10 spring element

[0057] 12 Connecting section

[0058] 14 Hold-down section

[0059] 20 Robot interface

[0060] 30 Base of the gripper

[0061] 40 Stop element

[0062] 42nd rib

[0063] 44 Stabilizing bridge

[0064] 50 shovels

[0065] 60 Connecting link

[0066] 121 First end of the connecting section

[0067] 122 Second end of the connecting section

[0068] 141 First free end of the hold-down section

[0069] 142 Second free end of the hold-down section

[0070] 143 Middle section of the hold-down section

[0071] 301 First Base Segment

[0072] 302 Second Base Segment

[0073] 421 Free end of a rib

[0074] 422 End of rib connection

[0075] 424 Stop surface

[0076] B Width of the food product

[0077] E Extension axis of the spine

[0078] F Guide rod

[0079] G Total force

[0080] H holding surface

[0081] P rib pair

[0082] R backbone of the stop element

[0083] S axis of symmetry

Claims

PATENT CLAIMS 1. Gripper (1) for gripping a product, in particular a food product, with a spring element (10) for holding down and positioning 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 gripper (1) 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 gripper (1).

2. Gripper (1) according to claim 1, wherein the spring element (10) is bent or has a bent section.

3. Gripper (1) according to claim 1 or 2, wherein the hold-down section (14) has a holding surface (H) which is curved or has a curved section, wherein the holding surface (H) is formed on a side of the hold-down section (14) facing away from the connecting section (12).

4. Gripper (1) according to one of the preceding claims, wherein the hold-down section (14) has a first free end (141), a second free end (142) and a central section (143) equidistant from the first free end (141) and the second free end (142), wherein the connecting section (12) is connected to the hold-down section (14) at the central section (143).

5. Gripper (1) according to one of the preceding claims, characterized by several spring elements (10), wherein two spring elements (10) are designed coplanarly.

6. Gripper (1) according to one of the preceding claims, wherein two spring elements (10) are arranged in a first plane and two further spring elements (10) are arranged in a second plane which is not equal to the first plane.

7. Gripper (1) according to one of the preceding claims, wherein two spring elements (10) arranged in a plane are symmetrical to each other.

8. Gripper (1) according to one of the preceding claims, characterized by 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 two coplanarly arranged ribs (42), and is connected to the base (30), wherein each 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 between the ribs (42) for holding, guiding and / or positioning.

9. Gripper (1) according to claim 8, wherein one spring element (10) or two coplanar spring elements (10) are 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.

10. Gripper (1) according to one of the preceding claims, wherein the spring element (10), or the spring element (10) and the stop element (40) are manufactured additively or in a 3D printing process.

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