Conveyor system for conveying food products

Abstract

Conveyor system (1) for movement on a substantially horizontal conveying surface (5) of a planar motor drive system (4), comprising a) a conveying carrier (2) with a loading surface (13) on the top of the conveying carrier (2) for receiving conveyed goods (14), in particular food products (14), b) a cleaning device (3) for cleaning the conveying surface (5) of the planar motor drive system (4), and c) a mechanical coupling between the conveying carrier (2) and the cleaning device (3) in a horizontal direction, such that the conveying carrier (2) carries the cleaning device (3) along during a horizontal movement along the conveying surface (5), characterized in that the mechanical coupling in a vertical direction perpendicular to the conveying surface (5) allows a range of motion between the conveying carrier (2) and the cleaning device (3) or a free vertical relative movement of the conveying carrier (2) relative to the cleaning device (3).

Description

Technical field of the invention The invention relates to a conveying system for transporting conveyed goods (e.g. food products) on a horizontal conveying surface of a planar motor drive system. Furthermore, the invention relates to a planar motor drive system with at least one such conveying system and a food processing plant with such a conveying system or with such a planar motor drive system. Finally, the invention also relates to the use of such a conveying system or such a planar motor drive system in a food processing plant. Background of the invention From the prior art (e.g. DE 10 2021 105 103 A1) it is known to transport food products (e.g. stacks of sausage slices or cheese slices) in a food processing plant on conveyor carriers, wherein the conveyor carriers are also referred to as "mover" or "shuttle" and are moved by a planar motor drive system on a horizontal conveying surface along a freely programmable conveying path. Furthermore, it is known from the prior art (see DE 10 2021 105 103 A1) to attach a cleaning device to the individual conveying carrier, which may consist, for example, of a cleaning brush or a scraper and has the task of keeping the conveying surface free of dirt (e.g., product residues) along the conveying path. This is intended to prevent dirt from penetrating the gap between the conveying surface of the planar motor drive system and the conveying carrier, which would cause the conveying carrier to leave its predetermined suspension height. A disadvantage of this known conveyor system with a cleaning device (e.g., cleaning brush) attached to the conveyor is the fact that the maximum load capacity of the conveyor is reduced by the mass of the cleaning device, since the planar motor drive system must keep both the actual conveyor and the attached cleaning device suspended at a height. Therefore, in the state of the art, the cleaning device must be designed to be as lightweight as possible, which in turn carries the risk that the cleaning device will be lifted off by dirt particles on the conveying surface and will not have a satisfactory cleaning effect. For the general technical background of the invention, reference should also be made to KR 10 2013 000 763 A and CN 107 802 214 A. However, these publications belong to completely different technical fields. Description of the invention The invention is therefore based on the objective of creating a correspondingly improved conveying system. This problem is solved by a conveying system according to the invention and the main claim. The conveying system according to the invention initially comprises, in accordance with the prior art described above, a conveying carrier which, according to the usual technical terminology, can also be referred to as a "mover" or "shuttle". On its upper side, the conveying carrier has a loading surface which serves to receive conveyed goods, such as food products (e.g., stacks of sliced ​​sausage or cheese). Furthermore, the conveying material carrier system according to the invention also has a cleaning device in accordance with the prior art described at the outset, in order to clean the conveying surface of the planar motor drive system. The cleaning device is connected to the actual conveying carrier via a mechanical coupling. This mechanical coupling, in accordance with the prior art described above, acts in a horizontal direction, so that the conveying carrier carries the cleaning device along with it during horizontal movement along the conveying surface. The mechanical coupling between the conveying carrier and the cleaning device thus acts in a horizontal direction and ensures that the conveying carrier and the cleaning device move synchronously on the conveying surface, i.e., in the same direction and at the same speed. The invention differs from the prior art described above in that the mechanical coupling between the conveying carrier and the cleaning device in the vertical direction (i.e., perpendicular to the conveying surface of the planar motor drive system) allows a range of motion between the conveying carrier and the cleaning device, or even permits free vertical relative movement of the conveying carrier relative to the cleaning device. In the conveying carrier system according to the invention, the actual conveying carrier can therefore move freely in the vertical direction (i.e., perpendicular to the conveying surface of the planar motor drive system), at least within the range of motion relative to the cleaning device. This is advantageous because the maximum load-bearing capacity of the conveying carrier is not limited by the weight of the cleaning device. In operation, the cleaning device therefore preferably rests on the conveying surface of the planar motor drive system, so that the cleaning device is supported and carried by the conveying surface of the planar motor drive system, while the conveying carrier is held at the required suspended height by the planar motor drive system. Thus, in the conveying carrier system according to the invention, the planar motor drive system preferably only needs to support the conveying carrier, and not the cleaning device. This also allows the cleaning device to be made relatively heavy, which largely prevents it from lifting off the conveying surface, as will be explained in more detail below. In a preferred embodiment of the invention, the cleaning device has a frame that surrounds the actual conveying material carrier in a frame-like manner. This ensures that the conveying material carrier carries the cleaning device along the conveying path when moving on the conveying surface. In this embodiment, the frame of the cleaning device has an inner contour, while the conveying material carrier has a correspondingly complementary outer contour. In the preferred embodiment of the invention, the inner contour of the cleaning device and the outer contour of the conveying material carrier are each rectangular. The inner contour of the frame of the cleaning device preferably has an interference with the outer contour of the conveying material carrier, so that a gap exists between the outer contour of the conveying material carrier and the inner contour of the frame of the cleaning device, which allows vertical relative movement of the conveying material carrier relative to the cleaning device. The frame of the cleaning device thus loosely surrounds the conveying material carrier to allow for the vertical clearance between the conveying material carrier and the frame of the cleaning device. Furthermore, it should be mentioned that the frame of the cleaning device and the conveying carrier are both preferably made partially of metal (e.g., steel, stainless steel). This is worth mentioning because direct contact between the metal conveying carrier and the metal frame of the cleaning device should be avoided during operation. Therefore, a spacer made of plastic (e.g., rubber) is preferably arranged between the frame of the cleaning device and the conveying carrier to prevent direct contact between the metal frame and the metal conveying carrier. This spacer is preferably detachably attached to the frame of the cleaning device. In the preferred embodiment of the invention, the frame of the cleaning device has projections on its upper surface that extend inwards beyond the inner contour of the frame and limit the vertical range of motion of the frame of the cleaning device relative to the conveying material carrier, so that the frame of the cleaning device cannot fall off the conveying material carrier when the conveying material carrier is lifted from the conveying surface of the planar motor drive system. The projections on the frame of the cleaning device thus preferably limit the vertical range of motion of the frame of the cleaning device relative to the conveying material carrier only in one direction. Regarding the cleaning device, it should be noted that it may include, for example, a cleaning brush or a scraper (e.g., a rubber lip). During operation, the cleaning brush or scraper rests on the conveying surface of the planar motor drive system to clean the conveying surface along the conveying path of the conveyed material carrier and keep it free of dirt. This is intended to prevent dirt particles from penetrating the gap between the conveyed material carrier and the conveying surface of the planar motor drive system, which would otherwise cause the conveyed material carrier to leave its predetermined suspension height. The cleaning brush or scraper is preferably arranged on the underside of the cleaning device's frame, so that the weight of the frame presses down on the cleaning brush or scraper. This means that the cleaning brush or scraper, with the full weight of the cleaning device's frame, presses down on the conveying surface, contributing to effective cleaning. It should be noted that the cleaning brush or scraper preferably rotates continuously and without interruption around the entire circumference of the cleaning device's frame to prevent dirt from entering the gap between the conveying carrier and the conveying surface of the planar motor drive system. This is advantageous because the cleaning effect is then independent of the conveying carrier's direction of movement on the conveying surface. Furthermore, it should be mentioned that the cleaning brush or wiper may consist at least partially of polytetrafluoroethylene (PTFE), also known under the product name Teflon®. Alternatively, the wiper may be designed as a rubber lip. Furthermore, it should also be mentioned that the cleaning brush or wiper is preferably mounted on the frame of the cleaning device in a replaceable manner. This is advantageous because a worn cleaning brush or wiper can then be easily replaced without having to replace the entire frame. In the preferred embodiment of the invention, the actual conveying material carrier has an upper part and a lower part, wherein the upper part is mechanically detachably connected to the lower part, for example by a snap-fit ​​connection. The lower part can thus have locking pins on its upper side that project upwards and can be engaged in locking recesses on the underside of the upper part. It has already been mentioned above that the mechanical coupling between the conveying carrier and the cleaning device in the conveying carrier system according to the invention allows a vertical range of motion. This vertical range of motion of the conveying carrier relative to the cleaning device is preferably at least 1 mm, 2 mm, 3 mm or even at least 5 mm. Furthermore, it should be mentioned that the conveying system according to the invention is generally suitable for receiving and conveying goods. Preferably, however, the conveying system according to the invention is designed for conveying food products. For this purpose, the conveying system must meet certain requirements, which relate, for example, to hygiene and are defined, among other things, in EU Directive 2006 / 42 / EC. The conveyed food products could, for example, be stacks of sliced ​​sausage or cheese, to name just two examples. The placement of the conveyed goods (e.g., stacks of sausage or cheese slices) on the loading platform of the conveying carrier and the removal of the conveyed goods from the loading platform are preferably carried out by so-called finger conveyors, which grip the conveyed goods from underneath. For this purpose, several parallel and elongated recesses are preferably arranged in the loading platform of the conveying carrier, into which the finger conveyors can immerse themselves during placement and removal of the conveyed goods in order to grip them from underneath. As mentioned above, the vertical range of motion between the cleaning device and the conveying carrier offers the advantage that the maximum load-bearing capacity of the conveying carrier is not reduced by the weight of the cleaning device. The cleaning device can therefore be made heavier to achieve a high contact force and a correspondingly good cleaning effect. For example, the cleaning device can have a mass of at least 50 g, 100 g, 200 g, or at least 300 g. The conveying system according to the invention, which is suitable for use with a planar motor drive system, has been described above. However, the invention also claims protection for a planar motor drive system with at least one such conveying system. Regarding the design and operation of the planar motor drive system, reference can be made to the state of the art, and such planar motor drive systems are also commercially available. For example, the German company Beckhoff Automation GmbH & Co. KG markets a corresponding planar motor drive system under the product name XPlanar®. Alternatively, the planar motor drive system marketed by the German company Bosch Rexroth AG under the product name ctrlX FLOW6D® can be used. It should be noted that the planar motor drive system preferably operates electromagnetically and is contactless, meaning there is no physical contact between the conveying material carrier and the conveying surface of the planar motor drive system. Preferably, all conveying material carriers of the planar motor drive system are designed in the manner described above according to the invention, i.e., all conveying material carriers have an integrated cleaning device. Furthermore, it should be mentioned that the invention not only claims protection for the conveying system and the planar motor drive system with such a conveying system described above. Rather, the invention also claims protection for a food processing plant with such a conveying system. Finally, the invention also claims protection for the novel use of such a conveying system or such a planar motor drive system for conveying food products in a food processing plant. Brief description of the drawings Fig. 1 shows a perspective view of a conveying system according to the invention from a top-down oblique angle. Fig. 2 shows a perspective view of the cleaning device of the conveying system according to Fig. 1 without the actual conveying carrier. Fig. 3A shows a sectional view through the conveying system according to the invention. Fig. 3B shows an enlarged detail view from Fig. 3A. Fig. 4 shows a schematic representation of a planar motor drive system according to the invention with a conveying system according to the invention. Detailed description of the drawings The following describes the conveying system 1 according to the invention as shown in the drawings, which essentially consists of a conveying carrier 2 and a cleaning device 3. The conveying system 1 can be moved contactlessly along a conveying surface 5 of the planar motor drive system 4 by a planar motor drive system 4, wherein the conveying carrier 2 hovers at a specific height above the conveying surface 5 of the planar motor drive system 4, so that during operation a gap 6 exists between the conveying surface 5 of the planar motor drive system 4 and the conveying carrier 2. The planar motor drive system 4 consists of numerous rectangular modules 7, 8, 9, which are seamlessly assembled to form the conveying surface 5, as is known from the prior art. For example, the planar motor drive system 4 could be the system marketed by the German company Beckhoff Automation GmbH under the product name XPlanar®. The conveying carrier 2 is essentially rectangular and is surrounded by a similarly rectangular frame 10 of the cleaning device 3. The inner contour of the frame 10 has a slight oversize compared to the outer contour of the conveying carrier 2. This allows for vertical movement of the conveying carrier 2 relative to the frame 10 of the cleaning device. However, this range of motion is limited in the vertical direction by projections 11, which are arranged at the corners of the frame 10 of the cleaning device 3 and project inwards beyond the inner contour of the frame 10 of the cleaning device 3. If the conveying carrier 2 is lifted from the conveying surface 5 of the planar motor drive system 4, these projections 11 prevent the frame 10 of the cleaning device 3 from falling downwards. On its underside, the frame 10 carries a cleaning brush 12 that runs continuously around the entire circumference of the frame 10 of the cleaning device 3. This ensures a consistent cleaning effect regardless of the direction of movement of the conveying system 1 on the conveying surface 5. The cross-sectional view in Fig. 3A shows that the conveying carrier 2 consists of an upper part 2.1 and a lower part 2.2. The upper part 2.1 of the conveying carrier 2 has a loading surface 13 on its upper side for receiving conveyed goods 14 (see Fig. 4), where the conveyed goods 14 could be, for example, stacks of sausage slices or cheese slices, to name just two examples. In the loading area 13 of the conveying carrier 2 there are elongated parallel recesses 15, which make it possible for so-called finger conveyors to dip into the recesses 15 when removing the conveyed goods 14 from the loading area 15 or when depositing the conveyed goods 14 on the loading area 15 and thereby grip the conveyed goods 14 underneath. Furthermore, it should be noted that the upper part 2.1 of the conveying carrier 2 is connected to the lower part 2.2 of the conveying carrier 2 by a snap-fit ​​connection. This snap-fit ​​connection comprises locking pins 16, which are arranged in the upper surface of the lower part 2.2 and project upwards. The snap-fit ​​connection also includes locking receptacles 17 on the underside of the upper part 2.1. The locking pins 16 can engage in the locking receptacles 17, thereby establishing the snap-fit ​​connection between the upper part 2.1 and the lower part 2.2 of the conveying carrier 2. Furthermore, it should be noted that the frame 10 and the lower part 2.2 of the conveying carrier 2 are both made of stainless steel. Direct contact between the stainless steel frame 10 and the stainless steel lower part 2.2 should be prevented. Therefore, a spacer 18, which can be made of plastic, for example, is arranged between the frame 10 and the lower part 2.2 of the conveying carrier 2 and is detachably mounted in the frame 10. Furthermore, Fig. 3B also shows that the cleaning brush 12 is detachably mounted in the frame 10 of the cleaning device 3. Therefore, if the cleaning brush 12 becomes worn, it can be easily replaced. Advantages of the invention One advantage of the invention is that the maximum load capacity (payload) of the conveying carrier on the planar motor drive system is not reduced by the weight of the cleaning device. As a result, the maximum load capacity (payload) can be increased. Another advantage of the invention is that the cleaning device can be made heavier, which leads to a higher contact force of the cleaning device on the conveying surface and thus to a better cleaning effect. Furthermore, the circumferential arrangement of the cleaning brush or scraper prevents dirt from entering the gap between the conveying material carrier and the conveying surface of the planar motor drive system, regardless of the direction of movement. In general, it can be said that the interference immunity of the conveying system according to the invention is significantly higher than in the prior art. Reference symbol list 1 Conveyor system 2 Conveyor 2.1 Upper part of the conveyor 2.2 Lower part of the conveyor 3 Cleaning device 4 Planar motor drive system 5 Conveying surface of the planar motor drive system 6 Gap between the conveying surface of the planar motor drive system and the conveyor 7-9 Modules of the planar motor drive system 10 Frame of the cleaning device 11 Projections on the upper side of the frame of the cleaning device 12 Cleaning brush on the underside of the frame of the cleaning device 13 Loading surface of the conveyor 14 Conveyed goods 15 Recesses in the loading surface of the conveyor for gripping the food product on the loading surface 16 Locking pin in the lower part of the conveyor 17 Locking receptacle in the upper part of the conveyor 18 Spacer between the frame of the cleaning device and the conveyor

Claims

Conveyor system (1) for movement on a substantially horizontal conveying surface (5) of a planar motor drive system (4), comprising: a) a conveying carrier (2) with a loading surface (13) on the upper side of the conveying carrier (2) for receiving conveyed goods (14), in particular food products (14); b) a cleaning device (3) for cleaning the conveying surface (5) of the planar motor drive system (4); and c) a mechanical coupling between the conveying carrier (2) and the cleaning device (3) in a horizontal direction, such that the conveying carrier (2) carries the cleaning device (3) along during a horizontal movement along the conveying surface (5), characterized in that d) the mechanical coupling in a vertical direction, perpendicular to the conveying surface (5), allows a range of motion between the conveying carrier (2) and the cleaning device (3) or a free vertical relative movement of the conveying carrier (2) relative to the cleaning device (3). Conveyor carrier system (1) according to claim 1, characterized in that the cleaning device (3) rests on the conveying surface (5) of the planar motor drive system (4) during operation and is supported in the vertical direction solely by the conveying surface (5) of the planar motor drive system (4), so that the cleaning device (3) does not form a load-bearing capacity in the vertical direction for the conveying carrier (2). Conveyor carrier system (1) according to one of the preceding claims, characterized in that a) the cleaning device (3) forms a frame (10) which surrounds the conveying carrier (2) in a frame-like manner, and / or b) the frame (10) of the cleaning device (3) has an inner contour and the conveying carrier (2) has an outer contour, wherein the inner contour of the frame (10) of the cleaning device (3) is shaped complementarily to the outer contour of the conveying carrier (2). Conveyor carrier system (1) according to claim 3, characterized in that a) the inner contour of the frame (10) of the cleaning device (3) is substantially rectangular, b) the outer contour of the conveying carrier (2) is substantially rectangular, and c) the inner contour of the frame (10) of the cleaning device (3) has an excess compared to the outer contour of the conveying carrier (2), so that there is a gap between the outer contour of the conveying carrier (2) and the inner contour of the frame (10) of the cleaning device (3), which allows the vertical relative movement of the conveying carrier (2) relative to the cleaning device (3). Conveyor carrier system (1) according to claim 3 or 4, characterized in that a) the frame (10) is made at least partially of metal, in particular of steel, b) the conveying carrier (2) is made at least partially of metal, in particular of steel, and c) a spacer (18) made of plastic is arranged between the frame (10) and the conveying carrier (2), wherein the spacer (18) prevents direct contact between the metal frame (10) and the metal conveying carrier (2). Conveyor carrier system (1) according to one of claims 3 to 5, characterized in that the frame (10) of the cleaning device (3) has projections (11) on its upper side which extend inwards beyond the inner contour of the frame (10) and limit the vertical range of motion of the frame (10) of the cleaning device (3) relative to the conveying carrier (2), so that the frame (10) of the cleaning device (3) cannot fall off the conveying carrier (2) when the conveying carrier (2) is lifted off the conveying surface (5) of the planar motor drive system (4). Conveyor system (1) according to one of the preceding claims, characterized in that a) the cleaning device (3) has a cleaning brush (12) or a scraper, wherein the cleaning brush (12) or the scraper rests on the conveying surface (5) of the planar motor drive system (4) during operation in order to clean the conveying surface (5) of a planar motor drive system (4), and / or b) that the cleaning brush (12) or the scraper is arranged on the underside of the frame (10) of the cleaning device (3), and / or c) that the cleaning brush (12) or the scraper runs continuously and without interruption around the entire circumference of the frame (10) of the cleaning device (3) in order to prevent the ingress of dirt into the gap between the conveying carrier (2) and the conveying surface (5) of the planar motor drive system (4), and / or d) that the cleaning brush (12) or the scraper is made at least partially of polytetrafluoroethylene consists,and / ore) that the wiper has at least one rubber lip, and / orf) that the cleaning brush (12) or the wiper is replaceable. Conveyor carrier system (1) according to one of the preceding claims, characterized in that a) the conveying carrier (2) has an upper part (2.1) and a lower part (2.2), and / or b) that the upper part (2.1) is mechanically detachably connected to the lower part (2.2), in particular by a snap connection (16, 17), and / or c) that the snap connection (16, 17) has locking pins (16) in the lower part (2.2) and locking receptacles (17) in the upper part (2.1), wherein the locking pins (16) can be snapped into the locking receptacles (17). Conveyor system (1) according to one of the preceding claims, characterized in that a) the mechanical coupling between the conveying carrier (2) and the cleaning device (3) allows a vertical range of motion of the conveying carrier (2) relative to the cleaning device (3) of at least 1 mm, 2 mm, 3 mm or 5 mm, and / or b) that the conveying carrier system (1) is designed for use with food products (14), in particular in accordance with EU Directive 2006 / 42 / EC, and / or c) that the conveying carrier (2) has several parallel and elongated recesses (15) in the loading area (13) for gripping the conveyed product (14) when the conveyed product (14) is placed on the conveying carrier (2) or when the conveyed product (14) is removed from the conveying carrier (2), and / or d) that the cleaning device (3) has a mass of at least 50 g, 100 g, 200 g or at least 300 g g has, in order to prevent,that the cleaning device (3) lifts from the conveying surface (5) of the planar motor drive system (4). Planar motor drive system (4) with at least one of the preceding conveying material carrier systems according to one of claims 1 - 9, wherein the conveying material carrier system (1) is movably arranged on the conveying surface (5) of the planar motor drive system (4). Planar motor drive system (4) according to claim 10, characterized in that a) all conveying carriers (2) on the conveying surface (5) of the planar motor drive system (4) are designed as conveying carrier systems according to one of claims 1 to 9, and / or b) that the planar motor drive system (4) operates electromagnetically, and / or c) that the planar motor drive system (4) operates without contact, without any physical contact between the conveying carrier (2) and the conveying surface (5) of the planar motor drive system (4). Planar motor drive system (4) according to claim 10 or 11, characterized in that a) the conveying carrier (2) floats at a certain height above the conveying surface (5) of the planar motor drive system (4) during operation, and b) the vertical range of motion of the conveying carrier (2) relative to the cleaning device (3) is greater than the height of the conveying carrier (2). Food processing plant with a conveying system (1) according to one of claims 1 to 9 or with a planar motor drive system (4) according to one of claims 10 to 12. Use of a conveying system (1) according to one of claims 1 to 9 or a planar motor drive system (4) according to one of claims 10 to 12 for conveying food products (14) in a food processing plant.

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