Method and system for processing a group of egg trays

Abstract

Method for processing a group of egg trays, each of the trays (T) being filled with eggs (E), wherein the group of egg trays includes a plurality of stack layers, each stack layer consisting of a plurality of parallel rows of egg tray stacks (S), wherein a robotic destacker (8) successively transfers the rows of egg tray stacks (S) of each stack layer to a first conveyor section (1), wherein the first conveyor section (1) transfers the rows of egg tray stacks successively to a downstream second conveyor section (2), wherein the robotic destacker (8) places a first row of egg tray stacks onto the first conveyor section (1) and subsequently places a second row of egg tray stacks next to at least part of the first row of egg tray stacks.

Description

[0001] Title: Method and system for processing a group of egg trays

[0002] The invention relates to a method and system for processing a group of egg trays.

[0003] Processing, in particular destacking, a group of egg tray stacks is known per se. The destacking can e.g. involve depalletizing a pallet that holds the group of egg tray stacks. For example, to that aim, a robotic destacker can be utilized, the destacker being capable of lifting stack rows and moving a lifted stack row to a discharge conveyor assembly. As an example, Moba’s MR50 De-Palletizer is capable of de -palletizing known pallet systems such as the Eggs Cargo System (ECS) and has a maximum capacity of 191,000 eggs (530 cases) per hour. Operation of the MR50 can e.g. be viewed on Youtube (https: / / www. youtube. com / watch?v=83HlgioXrFU).

[0004] In the know system, the robotic destacker lifts a first row of egg tray stacks and places that first row of stacks at a dedicated holding position onto a first conveyor. Subsequently, the first conveyor discharges the first row of egg trays towards a downstream second conveyor for further processing. Next, the holding position of the first conveyor receives a second row of egg tray stacks from the robotic destacker, and the discharge process is repeated. These steps are repeated until the entire group of egg tray stacks has been destacked. A disadvantage is that the robotic destacker has to wait to put down a next row of egg tray stacks before the first conveyor has discharged a previous row of egg tray stacks. Moreover, usually, a group of egg tray stacks is divided by a number of intermediate (horizontal) divider elements (e.g. having about the same size, viewed in horizontal directions, as a bottom pallet that carries the group of egg tray stacks), which divider elements are usually also removed by the robotic destacker. The removing of such a horizontal divider element (also called a “layer pad”) can lead to a significant delay in the entire destacking operation.

[0005] EP0638493 discloses automatically transferring works from a multilayer carriage to the parallel conveyor system without resorting to man power. A parallel conveyor system comprises one way conveyor composed of a long conveyor and a short conveyor which follows the long conveyor.

[0006] The present invention aims to provide an improved, more efficient method for processing a group of egg trays. In particular, the invention aims to overcome or reduce the above-mentioned disadvantages.

[0007] According to an aspect of the invention, to this aim there is provided a method for processing a group of egg trays, each of the trays being filled with eggs, wherein the group of egg trays includes a plurality of stack layers, each stack layer consisting of a plurality of parallel rows of egg tray stacks, wherein a robotic destacker successively transfers the rows of egg tray stacks of each stack layer to a first conveyor section, wherein the first conveyor section transfers the rows of egg tray stacks successively to a downstream second conveyor section, wherein the robotic destacker places a first row of egg tray stacks onto the first conveyor section and subsequently places a second row of egg tray stacks next to at least part of the first row of egg tray stacks.

[0008] In this way, significantly improved processing of the group of egg trays can be achieved. In particular, the first conveyor section can be used to receive more than one row (e.g. at least two rows) of egg trays next to each other, wherein the robotic destacker can e.g. make use of mutually different positions of the first conveyor section for putting down the subsequent egg tray stack rows. It is preferred that at least two egg tray stack rows can be located next to each other on the first conveyor section (i.e. that at least a first egg tray stack row and at least part of a subsequent second egg tray stack row can be located next to each other on the first conveyor section). The more than one (e.g. two or three) egg tray stack rows can be discharged from the first conveyor section (to a downstream second conveyor section) during a respective egg tray stack row discharging period. At the same time, the robotic destacker can be used for removing a said horizontal divider element (if any) from a part of the group of egg trays that is still to be destacked. As a result, optimum egg tray processing can be achieved.

[0009] Also, an aspect of the invention provides a system for processing a group of egg trays, the system being configured to carry out a method according to the invention. Advantageously, the system includes:

[0010] -a first conveyor section, configured to support more than one row of egg tray stacks, and to transfer the rows of egg tray stacks successively to a downstream second conveyor section;

[0011] - a robotic destacker configured to successively transfer rows of egg tray stacks of each stack layer to the first conveyor section; wherein the system includes a controller for controlling destacking operation, characterized in that the controller is configured such that during operation the robotic destacker places a first row of egg tray stacks onto the first conveyor section and subsequently places a second row of egg tray stacks next to at least part of the first row of egg tray stacks.

[0012] In this way, above-mentioned advantages can be achieved.

[0013] Further, extra advantageous embodiments of the invention are described in the dependent claims.

[0014] In the following, the invention will be explained further using exemplary embodiments and drawings. The drawings are schematic. In the drawings, similar or corresponding elements have been provided with similar or corresponding reference signs. In the drawings:

[0015] Figure 1A depicts a top view of a plurality of stack layers;

[0016] Figure IB depicts a front view of the plurality of stack layers shown in Fig 1A; Figure 2 schematically a top view of an example of a known system for processing a group of egg trays;

[0017] Figure 3 schematically a top view of a non-hmiting example of a system for processing a group of egg trays according to the present invention;

[0018] Figure 4 is similar to Fig. 3, showing a first destacking step;

[0019] Figure 5 is similar to Fig. 3, showing a second destacking step;

[0020] Figure 6 is similar to Fig. 3, showing a third destacking step; and Figure 7 is similar to Fig. 3, showing a fourth transfer step.

[0021] Figures 1A, IB depict a group G of stacked egg trays T. The group G of egg tray stacks S can e.g. be supported on a pallet P. Orthogonal directions x, y, z are depicted by respective arrows in these drawings.

[0022] Each of the trays T is filled with eggs E . The group G of egg trays T includes a plurality of stack layers SL, each stack layer consisting of a plurality of parallel rows R of egg tray stacks S (and each stack S consisting of a plurality of stacked egg trays T, e.g. at least four or five filled egg trays T per stack S). In the present example, each layer SL has three egg tray stack rows R(l), R(2), R(3). In this example, each row R(l), R(2), R(3) of egg tray stacks includes four egg tray stacks S.

[0023] Preferably, the group of egg trays includes at least one horizontal divider element D (e.g. a layer pad, known per se) for separating a first stack layer from a second stack layer. In this example, all stack layers SL are separated by intermediate divider elements D (see Fig. IB).

[0024] Figure 2 schematically shows a known system for processing such a group of egg trays. The system includes a first conveyor section 1’, configured to support a single row of egg tray stacks S, and to transfer the row of egg tray stacks successively to a downstream separate second conveyor section 2’ (which can also be part of the system, and can be aligned with the first conveyor section 1’, e.g. extending in parallel with the first conveyor section 1’). In particular, the first conveyor section 1’ defines a dedicated holding position (i.e. buffer position) for supporting a single egg tray stack row R(l), R(2), R(3) before that row is discharged to the downstream second conveyor section.

[0025] In the known system, two separate conveyors 1’, 2’ provide the first and second conveyor section.

[0026] The system can include a stack supply conveyor 3 for supplying a group of stacks, to be depalletized, towards a destacking position.

[0027] Also, there is provided a robotic destacker 8 (known per se) configured for destacking the group of egg tray stacks that is placed in a respective destacking position. In particular, the robotic destacker is configured to successively transfer (top) rows R(l), R(2), R(3) of egg tray stacks S of each stack layer to the first conveyor section T. The system has a controller or control unit C’ for controlling destacking operation. In a known system the robotic destacker 8 is also configured to engage the divider element D to remove that element from the second stack layer.

[0028] The robotic destacker 8 can e.g. include a manipulator unit, in particular a manipulator head 9, movable in three orthogonal directions (x, y, z) by a manipulator arm, e.g. an articulated arm 10 (know a such). Thus, the manipulator unit 3 is configured for moving the head 9 to each of the first area Al, second area A2 and pallet loading area PA, as well as the optional spacer structure providing station 14.

[0029] For example, robotic destacker 8 can include an articulated robot, having an articulated arm 10, a distal end of the arm 10 having a mounting structure for holding a robot manipulator head 9. The robotic destacker 8 can e.g. be configured for rotating the respective articulated arm 10 (and head 9) about a vertical axis (indicated by arrow R1 in Fig. 1). Besides, the robotic destacker 8 can e.g. be configured to pivot the head 9 with respect to the arm 10 in one or more pivot directions and / or to rotate the head 9 about a vertical axis with respect to the arm, allowing a large number of degrees of freedom for the manipulator head 9. The robotic destacker 8 can include various electric, pneumatic and / or hydraulic actuators (known as such) for providing respective manipulator translations and / or rotations as is clear to the skilled person. The destacker 8 can e.g. be or be similar to the Moba MR50 depalletizing robot.

[0030] As follows from the drawing the manipulator head 9 (known per se) can include a row of lifting elements (e.g. teeth) 22 configured for picking up one row of egg tray stacks R(l), R(2), R3). For example, one pair of lifting elements 22 can be provided for supporting (and lifting) one stack S of each stack row. Thus, in case of handling stack rows of four adjoining stacks, eight such lifting elements 22 can be available.

[0031] In the present example, the gripper head 9 can also include dedicated gripping means 23 for picking up a stack divider element D. For example the manipulator head 9 can include a pair of opposite, spaced-apart gripper plates (blades) 23, configured for releasingly holding (e.g. clamping) such a divider element D from the top of the tray stack group (if available). The robot 8 can be arranged to pick-up the spacer structure (e.g. sheet or tray or layer pad) D and deposit the picked-up spacer structure D at a nearly divider receiving area DRA.

[0032] The control unit or controller means C’ of the system can e.g. include a computer, microcontroller, controller software, hardware and / or the like, for controlling the various system components 1, 2’, 3’, 8 (such as activating, deactivating, steering, timing and / or synchronization of component actions, etc.), as will be appreciated by the skilled person. The system can include communication links, e.g. wired and / or wireless signal transmission means, for transmitting respective control signals between the control unit C’ and other system components.

[0033] Operation of the known system, shown in Figure 2, involves transferring the three top stack rows R(l), R(2), R(3) from the group of stack rows one by one to the first conveyor 1’. In particular, a first stack row R(l) (of four stacks S of egg trays T, of a top layer of stacks S of egg trays T) is transferred first by the robotic destacker 8 to the first conveyor 1’ (the result being depicted in Fig. 2). Next, the first conveyor 1’ transfers the first stack row R(l) to the second conveyor 2’, for further transport, after which a second stack row R(l) (of the top layer of stacks S of egg trays T) can be transferred by the robotic destacker 8 to the first conveyor 1’. Next, the first conveyor 1’ transfers the second stack row R(2) to the second conveyor 2’, for further transport, after which a third stack row R(l) (of the same top layer of stacks S of egg trays T) can be transferred by the robotic destacker 8 to the first conveyor 1’. Then, the divider elements D becomes available, and can be lifted by the robotic destacker (using its clamps 23) and transferred to the respective receiving area, e.g. for storage and reuse.

[0034] Figure 3 depicts a system according to an example of the invention.

[0035] The system includes a first conveyor section 1, configured to support more than one row of egg tray stacks S , in particular at least two rows of egg tray stacks S, and to transfer the rows of egg tray stacks successively to a downstream second conveyor section 2. Also, the system includes a robotic destacker 8 configured to successively transfer rows of egg tray stacks S of each stack layer to the first conveyor section 1. Further, the system includes a controller C for controlling destacking operation. The system differs from the system shown in Figure 2 in that the controller C is configured such that during operation the robotic destacker 8 places a first row R(l) of egg tray stacks S onto the first conveyor section 1 and subsequently places a second row R(2) of egg tray stacks S next to the first row R(l) of egg tray stacks, onto the first conveyor section 1 as well. It follows that the first conveyor section 1 is preferably configured for supporting at least two (mutually aligned) rows R(l), R(2), R(3) of tray stacks at the same time. In other words: an upper stack supporting surface of the first conveyor section 1 has a length L that is at least twice a length M (see Fig. 1A) of a row of egg stack trays of the stacked tray group G, such that the stack supporting surface of the first conveyor section 1 can accommodate a plurahty of these stack rows R(l), R(2), R(3).

[0036] The controller C can be configured for controlling the first conveyor section 1 such that the first conveyor section 1 moves only part of the first row R(l) of egg tray stacks to the second conveyor section 2 before receiving the second row R(2) of egg tray stacks.

[0037] Preferably, as in the above example, during operation the group of egg trays G includes one or more horizontal divider elements D for separating a first stack layer SL from a second stack layer SL. Advantageously, the present the system includes a divider element removal structure, for example the robotic destacker 8, for removing the divider element D when the first conveyor section 1 moves one or more rows R(l), R(2), R(3) of egg tray stacks to the second conveyor section 2 (See Figures 5- 6). As follows from the above, the robotic destacker 8 is preferably configured to engage the divider element D (e.g. via dedicated clamping means 23) to remove that element D from a stack layer SL.

[0038] During operation, the system (schematically shown Figure 3) can efficiently carry out a method for processing the group G of stacked egg trays T. This is shown in Figures 3-7 (therein, the robot detacher unit 8 has not been shown in Figures 4, 5 and 7 for clarity reasons).

[0039] During operation, the group G of egg trays that is to be destacked can be placed near the destacker 8, for example utilizing a stack group supplier 3 (see Fig. 3). Then, the robotic destacker 8 successively transfers the rows of egg tray stacks S of each stack layer SL to the first conveyor section 1 (e.g. under control of the control unit C), to remove the stack layers SL from the group G (until the group has been totally destacked). Also, the first conveyor section 1 can transfer the various rows R(l), R(2), R(3) of those layers SL successively to the downstream second conveyor section 2, for further transport and / or processing of these stacks S of trays T. In particular, during operation, the robotic destacker 8 places a first row of egg tray stacks onto the first conveyor section 1 and subsequently places a second row of egg tray stacks next to at least part of the first row of egg tray stacks. Good result can be achieved in case the first conveyor section 1 moves only part of the first row of egg tray stacks to the second conveyor section 2 before receiving the second row of egg tray stacks. In case the group of egg trays includes at least one horizontal divider element D for separating a first stack layer from a second stack layer, the divider element D can be removed from the second stack layer during a divider element removal period. Then, it is highly preferred that the first conveyor section 1 moves one or more rows of egg tray stacks to the second conveyor section 2 during the divider element removal period. For example, during operation, the robotic destacker 8 engages the divider element D to remove that element from the second stack layer.

[0040] Referring in particular to the example of Figures 3-7, during operation, the robotic destacker 8 picks up the first row R(l) of egg tray stacks (of the instantaneous top layer SL of tray stack rows) from the group G and places the first row R(l) of egg tray stacks onto the first conveyor section 1. The result is depicted in Figure 4. Therein, the first row R(l) of egg tray stacks S has been put into the first conveyor section 1, e.g. at a position near or next to the downstream second conveyor section 2.

[0041] Subsequently, the robotic destacker 8 picks up the second row R(2) of egg tray stacks (of the instantaneous top layer SL of tray stack rows) from the group G and places the second row of egg tray R(2) stacks next to the first row of egg tray stacks (onto the same first conveyor section 1), in particular at an upstream location (i.e. next to an upstream edge of the first row R(l) of egg tray stacks that faces away from the second conveyor section 2).

[0042] Subsequently, preferably, the first conveyor section 1 can move only part of the two adjoining egg tray stack rows R(l), R(2), in particular part of the first egg tray stack row R(l), onto the second conveyor section 2. The result is depicted in Figure 5. Therein, part of the (downstream positioned) first stack row R(l) has been moved onto the second conveyor section 2 by the first conveyor section, wherein a remaining part of that first stack row R(l) is still located on the first conveyor section. Also, the entire subsequent second stack row R(2) is still located on the first conveyor section 1.

[0043] Next, a third stack row R(3) of the upper layer SL (if any) can be removed, by the robotic destacker 8, and placed onto the first conveyor section 1, adjoining the previously placed second stack row R(2). These steps can be repeated if required to remove any further stack rows until an upper stack layer SL of the tray stack group G has been removed from the stack group G. The result is depicted in Figure 6. In this case, after the layer removal the top of the stack group G is being provided by a divider element D, that had been present below the removed top stack layer SL (to support that layer SL). The divider element D can then be removed from the stack group G (preferably utilizing the robotic destacker 8 as well), and e.g. be deposited at a said divider element area DRA (e.g. for storage, transport and / or reuse). Removal of the element D is indicated by arrow K in Figure 6. Preferably, during the removing of the divider element D, the first conveyor section 1 is activated (by the respective system controller C) to remove some or all tray stack rows that are still located on that first conveyor section 1, i.e. to discharge those stack rows to the downstream second conveyor section (which is preferably activated at the same time for receiving the stack rows). Discharge movement of the rows is indicated by arrows H in Figure 6. A result is depicted in Figure 7, wherein the divider element D has been removed from the stack group G, and a new stack layer SL is available to be destacked by the robotic destacker 8. Optionally, one or more stack rows of a previous stack layer can still be present on the first conveyor section 1. The above steps can be repeated for destacking the remaining part of the stack group G, a will be clear to the skilled person.

[0044] In this way, a very efficient, swift and reliable stack tray group destacking can be achieved.

[0045] While the invention has been explained using exemplary embodiments and drawings, these do not limit the scope of the invention in any way, said scope being provided by the claims. It will be appreciated that many variations, alternatives and extensions are possible within said scope, as will be clear to the skilled person from the description and the drawings.

[0046] For example, each of the first conveyor section 1 and second conveyor section 2 can be configured in various ways, e.g. including one or more of a belt-conveyor, roller conveyor, and / or the-like. For example, each of the conveyor sections 1, 2 can extend in a substantially horizontal direction.

[0047] According to an embodiment, the first conveyor section 1 and second conveyor section 2 can be provided by a single conveyor, the respective sections 1, 2 e.g. optionally being independently controllable by the controller C, as will be appreciated by the skilled person. Also, according to an embodiment, the first conveyor section 1 and second conveyor section 2 can be provided by one or more separate conveyors.

[0048] Also, one or more of the at least two conveyor sections 1, 2, in particular at least the first conveyor section 1, can optionally be synchronized with the robotic destacker 8, at least during the receiving of the rows of egg tray stacks. In particular, the synchronization can include synchronization of horizontal speeds (such that a horizontal speed difference between a speed of a stack receiving surface of the respective conveyor and a speed of the row of egg tray stacks that is deposited on that surface by the destacker 8 is substantially zero). As an example, the robotic destacker 8 can be configured to deliver each row of egg tray stacks at a horizontal speed that substantially corresponds to an instantaneous horizontal speed of the first conveyor section 1.

[0049] According to an embodiment, the two or three egg tray stack rows can be discharged from the first conveyor section (to a downstream second conveyor section) during a respective egg tray stack row discharging period. It should be noted that the discharging can include continuous or non- continuous (e.g. intermittent) discharging of egg tray stack rows, or a combination of such or other discharging options. It follows that the system can e.g. be configured to provide continuous discharging of egg tray stack rows and / or non-continuous (e.g. intermittent) discharging of egg tray stack rows, as will be clear to the skilled person.

Claims

Claims1. Method for processing a group of egg trays, each of the trays (T) being filled with eggs (E), wherein the group of egg trays includes a plurality of stack layers, each stack layer consisting of a plurality of parallel rows of egg tray stacks (S), wherein a robotic destacker (8) successively transfers the rows of egg tray stacks (S) of each stack layer to a first conveyor section (1), wherein the first conveyor section (1) transfers the rows of egg tray stacks successively to a downstream second conveyor section (2), characterized in that the robotic destacker (8) places a first row of egg tray stacks onto the first conveyor section (1) and subsequently places a second row of egg tray stacks next to at least part of the first row of egg tray stacks.

2. Method according to claim 1, wherein the first conveyor section (1) moves only part of the first row of egg tray stacks to the second conveyor section (2) before receiving the second row of egg tray stacks.

3. Method according to claim 1 or 2, wherein the group of egg trays includes at least one horizontal divider element (D) for separating a first stack layer from a second stack layer, wherein the divider element (D) is removed from the second stack layer during a divider element removal period, wherein the first conveyor section (1) moves one or more rows of egg tray stacks to the second conveyor section (2) during the divider element removal period.

4. Method according to claim 3, wherein the robotic destacker (8) engages the divider element (D) to remove that element from the second stack layer.

5. Method according to any of the preceding claims, wherein each row of egg tray stacks includes four egg tray stacks (S).

6. Method according to any of the preceding claims, wherein the robotic destacker (8) picks up the first row (R(l)) of egg tray stacks from the group (G) and places the first row (R( 1)) of egg tray stacks onto the first conveyor section (1), preferably at a position near or next to the downstream second conveyor section (2).

7. Method according to any of the preceding claims, wherein the robotic destacker (8) picks up the second row (R(2)) of egg tray stacks from the group (G) and places the second row of egg tray (R(2)) stacks next to the first row of egg tray stacks onto the same first conveyor section (1), in particular at an upstream location next to an upstream edge of the first row (R(l)) of egg tray stacks that faces away from the second conveyor section (2).

8. Method according to any of the preceding claims, wherein the first conveyor section (1) moves only part of the two adjoining egg tray stack rows (R(l), R(2)), in particular part of the first egg tray stack row (R(l)), onto the second conveyor section (2), after which part of the first stack row (R(l)) has been moved onto the second conveyor section (2) by the first conveyor section, wherein a remaining part of that first stack row (R( 1)) is still located on the first conveyor section (1) and the entire subsequent second stack row (R(2)) is still located on the first conveyor section (1).

9. Method according to any of the preceding claims, wherein a manipulator head (9) is used that includes a row of lifting elements, for example teeth (22), for picking up one row of egg tray stacks (R(l), R(2), R(3)).

10. Method according to any of the preceding claims, wherein two separate conveyors (1, 2) provide the first and second conveyor section.

11. Method according to any of the preceding claims, wherein the group (G) of egg tray stacks (S) is supported on a pallet (P).

12. Method according to any of the preceding claims, wherein the two conveyor sections (1, 2) are independently controllable by a controller (C).

13. System for processing a group of egg trays, the system being configured to carry out a method according to any of the preceding claims, wherein the system includes:-a first conveyor section (1), configured to support more than one row of egg tray stacks (S), and to transfer the rows of egg tray stacks successively to a downstream second conveyor section (2);- a robotic destacker (8) configured to successively transfer rows of egg tray stacks (S) of each stack layer to the first conveyor section (1); wherein the system includes a controller (C) for controlling destacking operation, characterized in that the controller (C) is configured such that during operation the robotic destacker (8) places a first row of egg tray stacks onto the first conveyor section (1) and subsequently places a second row of egg tray stacks next to at least part of the first row of egg tray stacks.

14. System according to claim 13, wherein the controller (C) is configured for controlling the first conveyor section (1) such that the first conveyor section (1) moves only part of the first row of egg tray stacks to the second conveyor section (2) before receiving the second row of egg tray stacks.

15. System according to claim 13 or 14, wherein during operation the group of egg trays includes at least one horizontal divider element (D) for separating a first stack layer from a second stack layer, wherein the system includes a divider element removal structure for removing the divider element (D) when the first conveyor section (1) moves one or more rows of egg tray stacks to the second conveyor section (2).

16. System according to claim 15, wherein the robotic destacker (8) is configured to engage the divider element (D) to remove that element from the second stack layer.

17. System according to any of claims 13-16, wherein the robotic destacker (8) is configured to deliver each row of egg tray stacks at ahorizontal speed that substantially corresponds to an instantaneous horizontal speed of the first conveyor section (1), in particular providing synchronization between the robotic destacker (8) and first conveyor section (1) during the placing of the row of egg tray stacks onto the first conveyor section (1).

18. System according to any of claims 13-17, wherein the first and second conveyor sections (1, 2) are independently controllable by the controller (C).

Images