Storage and retrieval system and stack handling device

Abstract

A storage and retrieval system. A storage and retrieval system in which items are stored in containers (20). The containers are arranged in stack units (50). Each stack unit comprises a stand (30) comprising a stand top and one or more legs extending downwardly from the stand top. The containers are arranged in a stack on the stand tops. Each stack unit is movable by a vehicle (50) dimensioned to allow the vehicle to move under the stand tops. Each vehicle comprises a lifting mechanism movable between raised and lowered positions, respectively, to raise the stack unit off the ground and to lower the stack unit to the ground.

Description

[Technical field]

[0001] The present invention relates to a storage and retrieval system in which items are stored in a stack of storage containers. The present invention also relates to an apparatus for handling the stack of containers. In particular, the present invention relates to an apparatus for extracting containers from and inserting containers into a vertical stack of containers. [Background technology]

[0002] Certain commercial and industrial activities require a system that allows for the storage and retrieval of a large number of different products. WO2015 / 185628A describes a storage and retrieval system in which a stack of containers is placed in a grid storage structure. The containers are accessed from above by a handling device that operates on rails or tracks located on top of the grid framework structure. When the products are required, the containers containing the items are lifted from the grid storage structure by the handling device and transported to a picking station where the items can be picked from the containers before the containers are sent back to the grid storage structure.

[0003] Systems such as that described in WO2015 / 185628A can require large amounts of space to house the grid storage structures and high capital and time costs to build. It would be desirable to provide a storage and retrieval system with reduced space, capital, and construction time requirements. Summary of the Invention

[0004] The invention is defined in the appended claims.

[0005] Storage and Retrieval Systems A storage and retrieval system is provided, the storage and retrieval system comprising: one or more stack units, where each stack unit comprises: a stand comprising a stand top and one or more legs extending downwardly from the stand top; one or more containers located on the stand top; and one or more vehicles dimensioned to enable the vehicles to move under the stand top, each vehicle having a lifting mechanism movable between a raised position and a lowered position to raise the stack unit off the ground and lower the stack unit to the ground, respectively.

[0006] By providing an intermediate stand between the container (or any other object) and the vehicle, the vehicle can quickly and efficiently lift and move the container without having to wait for the container to be loaded directly onto the vehicle. Furthermore, once the vehicle has placed the stack unit in a desired location, the vehicle is free to immediately go to a different location (e.g., to move another stack unit) without having to wait for the container to be unloaded from the vehicle. Furthermore, multiple stack units can be stored centrally without requiring any storage structure other than a floor area large enough to store multiple stack units, thereby reducing capital and construction time costs compared to the grid storage structures described in the background section.

[0007] When multiple containers are located on the stand top, the containers may be stacked directly on top of each other to form a vertical stack. The containers may be stacked reversibly, i.e., they can be easily stacked and dismantled. The stack may comprise containers of different heights. The stack may be located directly on the stand top.

[0008] Arranging containers into vertical stacks is an efficient way of storing items at high density. Storing items in stackable containers also supports automation compared to fixed storage means such as shelves, because the items can be reorganized by rearranging the containers in the stack or by moving containers between different stacks, which may be easier than directly reorganizing the items themselves. Furthermore, by forming or placing each stack on a stand that can accommodate a lifting vehicle underneath, the entire stack can be conveniently and efficiently transported and moved around the facility by simply lifting the stand with the desired stack on it.

[0009] Each container may include one or more interlocking features configured to reversibly interlock with one or more corresponding interlocking features of adjacent containers in the vertical stack. For example, the top of each container may include one or more recesses and the bottom of each container may include one or more corresponding protrusions, or vice versa. The interlocking features help the stack of containers remain stable, especially while the stack unit is being lifted and transported by a vehicle.

[0010] Each container may be removably receivable on the stand top, i.e., not fixed to the stand top. Each container may include one or more interlocking features configured to reversibly interlock with one or more corresponding interlocking features on the stand top. For example, the bottom of each container may include one or more protrusions and the top of the stand top may include one or more corresponding recesses. The interlocking features for enabling the containers to interlock with each other may be the same as the interlocking features for enabling each container to interlock with the stand, or they may be different. The interlocking features for interlocking the containers with the stand help the stack of containers to remain stable on the stand, especially when the stack unit is lifted and transported by a vehicle.

[0011] The stand top may include one or more positioning features configured to cooperate with one or more corresponding positioning features of one or more containers to help position the container into a particular location on the stand top. The positioning feature and the corresponding positioning feature may include, for example, tapered edges and may be located at the top of the stand top and the bottom of each container. The positioning feature of each container may also cooperate with a corresponding positioning feature on each container to help position the containers on top of each other when forming a vertical stack of containers.

[0012] Each container may be an open-top container (i.e., with an opening at the top of the container), which allows items to be easily placed in and removed from the container and aids in the automation of these tasks (e.g., by allowing a camera to view the contents of the container and by allowing a robotic arm to access the items within the container). To improve stability and maximize the use of the space available for storing stack units, the footprint of each container may be substantially the same as the footprint of the stand (i.e., the base of each container may be substantially the same size as the stand top).

[0013] Each vehicle may be an automated or autonomous vehicle, such as, for example, an automated guided vehicle (AGV) capable of following a fixed route, or an autonomous mobile robot (AMR) capable of planning its own route. This allows for the transport of the stack units to be automated, thereby further increasing the efficiency of the storage and retrieval system. Each vehicle may include a drive mechanism configured to enable the vehicle to move in multiple directions. For example, the drive mechanism may be configured to enable the vehicle to move back and forth in at least two orthogonal directions. The drive mechanism may enable the vehicle to rotate about a vertical axis to enable the vehicle to change direction. The storage and retrieval system may include a control system configured to direct one or more vehicles to pick up and move the stack units to a specific location within the storage and retrieval system.

[0014] When the lifting mechanism is in the raised position, the overall height of the vehicle may be higher than the height of the stand top above the ground, so that the stack unit can be lifted off the ground by the vehicle. When the lifting mechanism is in the lowered position, the overall height of the vehicle may be lower than the height of the stand top above the ground, so that the stack unit can rest on the ground with the vehicle underneath.

[0015] The lifting mechanism may comprise a lifting surface movable relative to the rest of the vehicle between a raised position and a lowered position. The lifting surface may engage the standtop (e.g., the bottom of the standtop) when the lifting surface is in the raised position and disengage from the standtop when the lifting surface is in the lowered position. The lifting surface (e.g., the top of the lifting surface) may comprise one or more interlocking features (e.g., protrusions or recesses) configured to reversibly interlock with one or more corresponding interlocking features of the standtop (e.g., the bottom of the standtop). The interlocking features of the vehicle and the standtop help the stack unit remain stable on the vehicle as it is lifted and transported. The lifting mechanism may comprise a linear actuator for raising and lowering the lifting surface. The linear actuator may be any suitable type of actuator, such as, for example, pneumatic, hydraulic, electric, etc. The lifting surface and the rest of the vehicle may rotate relative to each other about a vertical axis, allowing the vehicle to change direction in place without moving the stack unit on the lifting surface.

[0016] The stand top and one or more legs may define a space below the stand top and one or more side openings to allow vehicles to enter and exit the space. The one or more side openings may be defined between adjacent legs. Side openings may be defined on more than one side of the stand to allow vehicles to enter and exit the space from more than one direction. A pair of opposing side openings may be defined. Two pairs of opposing side openings may be defined, one pair oriented orthogonally to the other pair. The stand top may have a rectangular shape with four legs extending downward from four corners of the stand top. Side openings may be defined on each side of the stand between each pair of adjacent legs. This may allow vehicles to enter and exit the space below the stand top regardless of the orientation of the stack unit. Furthermore, if the stack units are arranged in a grid pattern such that the side openings of adjacent stack units are aligned, vehicles can efficiently travel from one side of the grid pattern to another by traveling "through" the grid pattern, rather than having to travel around the outside of the grid pattern. This also allows the stack units to be arranged more densely, since no or little access aisles for vehicles are required between the stack units.

[0017] Each vehicle may be dimensioned such that it can fit entirely vertically within the space below the standtop, in other words the maximum vertical dimension of each vehicle is smaller than the minimum vertical dimension of the space below the standtop.

[0018] The horizontal footprint of each vehicle may be substantially similar to or smaller than the horizontal footprint of each stack unit. Each vehicle may be dimensioned such that the lateral perimeter of each vehicle may be contained entirely within the space defined below the stand top (i.e., the vehicle does not extend laterally beyond the stand top). This allows vehicles to move and deposit stack units closer to other stack units or other objects or walls, improving storage density. Access routes for vehicles may also be smaller, so that the storage and retrieval system requires less space overall.

[0019] The bottom of each leg may be provided with wheels (e.g. caster wheels) that allow the stack unit to be pushed around when not being lifted by a vehicle. This may be useful, for example, for pushing the stack unit up and down ramps (e.g. onto a lorry) that may not be suitable for a vehicle when the stack unit is being lifted.

[0020] The storage and retrieval system may comprise a plurality of stack units arranged in a grid pattern (i.e., the stack units are arranged in a regular pattern along two orthogonal directions), allowing for a high density, space efficient arrangement.

[0021] The storage and retrieval system may include a storage area for storing one or more stack units. The stack units may be arranged in a grid pattern within the storage area.

[0022] The storage and retrieval system may further comprise a picking station where an item is picked from one or more containers of the stacking unit. At the picking station, a target container may be withdrawn from the stacking unit, thereby allowing an item to be picked from the target container. After picking, the container may be returned to the same or a different stacking unit and then returned to the storage area.

[0023] The storage and retrieval system may further comprise a filling station where empty or partially full containers are filled with items and positioned to form new stack units or transferred onto existing stack units. The new or updated stack units may then be transported to the storage area.

[0024] The storage and retrieval system may include a control system communicatively coupled to one or more vehicles. The control system may be configured to control the movement of the one or more vehicles to transport one or more stack units between the storage area, the picking station, and the filling station. For example, a newly formed or updated stack unit may be moved from the filling station to the storage area. When an item needs to be removed from a container in the stack unit, the stack unit may be moved from the storage area to the picking station. The stack unit may then be moved back to the storage area until the item is needed again. Alternatively, the stack unit may be moved from the picking station to the filling station when a container needs to be refilled or when the stack unit needs to receive a new container.

[0025] The storage area may comprise a container lifting device disposed above the stack units in the storage area. The container lifting device may be configured to transfer a container from the top of one of the stack units to the top of another of the stack units. The container lifting device may comprise a container grabber configured to releasably engage a container on the top of the stack unit. The container grabber may be further configured to move vertically to raise and lower the container. The container grabber may be further movable horizontally to transfer the container onto another stack unit.

[0026] The filling station and / or the picking station may comprise one or more stack handling devices as defined below.

[0027] Stack Processing Device A stack handling apparatus is provided for moving a container out of a vertical stack of containers and / or into a vertical stack of containers. The stack handling apparatus comprises: a stack receiving area for receiving a vertical stack of containers; a stack separation mechanism comprising a separation member configured to releasably engage a container in the stack, wherein the separation member is vertically movable within the stack receiving area to enable the separation member to engage any container in the stack and vertically lift the engaged container to separate the stack into an upper sub-stack and a lower sub-stack to expose a target container at an upper portion of the lower sub-stack; a container handling mechanism comprising a handling member configured to releasably engage a target container in the stack, the handling member being vertically movable relative to the stack receiving area and horizontally movable to enable the handling member to engage and horizontally withdraw the target container from the stack, and / or function in a reverse manner to insert a free container into the stack.

[0028] In this manner, the stack handling device allows efficient and direct access to any container in the stack and / or efficient and direct insertion of a container into any position within the stack. These tasks can be performed even when the containers in the stack have different height dimensions. The stack handling device may be useful in storage and retrieval systems where items are stored in containers arranged in vertical stacks and direct access to individual containers in the stack allows for efficient and timely retrieval of the items.

[0029] At least a portion of the handling member may be horizontally linearly movable towards and away from the stack receiving area, for example the handling member may comprise a retractable arm configured to extend and retract horizontally linearly towards and away from the stack receiving area.

[0030] At least a portion of the handling member may be pivotally mounted for horizontal movement towards and away from the stack receiving area.

[0031] At least a portion of the separating member and / or at least a portion of the handling member may be movable towards and away from the stack to engage and release containers in the stack, respectively. The separating member and / or the handling member may comprise engagement features for engaging corresponding features of the containers. The engagement features may be, for example, protrusions, recesses, openings, etc.

[0032] The stack separation mechanism may comprise a pair of horizontally opposed separation members configured to engage a container therebetween, and / or the container handling mechanism may comprise a pair of horizontally opposed handling members configured to engage a container therebetween.

[0033] The stack processing apparatus may further comprise a container receiving area horizontally adjacent to the stack receiving area, and the handling member may be vertically movable within the container receiving area and horizontally movable between the container receiving area and the stack receiving area to withdraw a target container from the stack into the container receiving area and / or insert a free container from the container receiving area into the stack.

[0034] The stack processing apparatus may further include a container port area horizontally adjacent to the container receiving area. The container port area may include a container port configured to receive a target container from the container receiving area and / or to receive a free container to be moved into the container receiving area.

[0035] The container port area may comprise multiple vertically arranged container ports. For example, the container ports may be located directly above or below each other, or they may be horizontally offset from each other at different vertical heights. Alternatively, the container ports may be located in a horizontal plane (at the same vertical height) around the container receiving area.

[0036] The handling member may be movable horizontally between the container receiving area and the container port area to enable the handling member to move a target container from the container receiving area to one or more of the container ports and / or move a free container from one or more of the container ports to the container receiving area.

[0037] The container handling mechanism may include a plurality of vertically disposed handling members, each of which may be vertically movable within the container receiving area independently of the other handling members, and at least one of the plurality of handling members may be horizontally movable between the container receiving area and the container port area.

[0038] At least one of the container ports may be an output port configured to receive a target container from the container receiving area, and at least one of the container ports may be an input port configured to receive a free container to be moved to the container receiving area.

[0039] The outgoing port may be connected to the ingoing port by a container path that is external to the container receiving area, along which the target container may travel from the outgoing port to the ingoing port. The container path may be configured to automatically transport the container from the outgoing port to the ingoing port. For example, the container path may be in the form of a conveyor. The container path may be continuous between the outgoing port and the ingoing port to allow the container to travel uninterrupted between the outgoing port and the ingoing port (although the container path may be configured to stop the container at one or more locations along the container path as necessary).

[0040] The outfeed and infeed ports may be arranged vertically. For example, the outfeed port may be arranged below the infeed port or vice versa. The container path may comprise a vertical conveying means configured to move the containers from the outfeed port level to the infeed port level, optionally via one or more intermediate levels between the outfeed and infeed ports. The vertical conveying means may be, for example, an inclined surface (e.g., an inclined conveyor) or a lifting mechanism (e.g., a section of a conveyor that is vertically movable).

[0041] The container receiving area may further comprise a container receiving surface configured to receive a target container from the handling members, deliver the target container to any one of the container ports, and / or receive a free container from any one of the container ports for insertion into the stack by the handling members. The container receiving surface may be vertically movable within the container receiving area independent of the handling members. The container receiving surface may be in the form of a conveyor.

[0042] The stack processing device may further comprise a container handling area configured to receive a target container from the container port to allow an article to be moved out of or into the container. The stack processing device may further comprise a buffer area for temporarily storing one or more containers without blocking the container handling area. The containers may be transported between the container port, the container handling area and the buffer area using a conveyor arrangement or other transport means. The container handling area and the buffer area may form part of the container path mentioned above.

[0043] The stack separation mechanism may further comprise a support member configured to releasably engage a container in the stack. The support member may be vertically movable within the stack receiving area and configured to engage a container in the lower substack while the separating member separates the stacks and / or while the handling member withdraws the target container. For example, the support member may engage the target container while the separating member separates the stacks and / or the support member may engage a container immediately below the target container while the handling member withdraws the target container. The support member helps the upper substack to be separated more smoothly from the lower substack and / or helps the target container to be withdrawn more smoothly from the lower substack.

[0044] The stack processing apparatus may further include a control system including a container recognition system configured to determine a vertical position of one or more containers in the stack. The control system may be configured to vertically move the separating member and / or the handling member based on the determined vertical positions. For example, the container recognition system may be configured to recognize a target container and a container immediately above the target container and determine their vertical positions in the stack.

[0045] The container recognition system may include a camera configured to capture one or more images of the containers in the stack and one or more processors configured to identify a visual identifier (e.g., a barcode, a QR code, etc.) on the container. The container recognition system may include a data store comprising data relating the visual identifier of the container to a height dimension of the container. The camera may be configured to capture one or more images of the stack when the stack approaches the stack receiving area or when the stack is within the stack receiving area. The container recognition system may alternatively include an RFID reader configured to read an RFID tag on each container to identify the container.

[0046] The stack separation mechanism may include a plurality of vertically disposed separation members that may be vertically movable within the stack receiving area independently of one another to allow the vertically disposed separation members to move into and engage a plurality of containers in the stack and vertically lift the engaged containers relative to one another to separate the stack into more than two sub-stacks.

[0047] The stack receiving area may be configured to receive a predetermined maximum number of vertically stacked containers. The number of vertically disposed separating members may at least correspond to the predetermined maximum number of vertically stacked containers to enable the vertically disposed separating members to move into and engage all containers in the stack and vertically lift all containers relative to one another to separate the stack into multiple substacks, each substack including only one container.

[0048] Stack Processing Station A stack processing station is provided, the stack processing station comprising: A first stack processing device as defined above; A second stack processing device as defined above, The first stack processing device is connected to the second device to enable a target container pulled from a stack in the first stack processing device to proceed to the second stack processing device for insertion into a stack in the second stack processing device.

[0049] For example, a first stack processing device may include an outgoing port and a second stack processing device may include an ingoing port that may be connected to the ingoing port by a container pathway that allows containers to travel from the outgoing port to the ingoing port. The container pathway may include a container processing area where articles may be placed in or removed from containers traveling along the pathway.

[0050] Stack Processing System A stack processing system is provided, the stack processing system comprising: one or more vertical stacks of containers; one or more stack processing devices or one or more stack processing stations as defined above.

[0051] The stack handling system may comprise one or more stack units of the storage and retrieval system defined above, comprising one or more vertical stacks of containers.

[0052] Stack Processing Method There is provided a method for processing a vertical stack of containers using the stack processing apparatus defined above, the method comprising the steps of: (i) vertically lifting containers within the stack to separate the stack into an upper sub-stack and a lower sub-stack; (ii) horizontally withdrawing a container from the stack that is on top of the lower substack, or horizontally inserting a container between the upper and lower substacks; (iii) lowering the upper sub-stack onto the lower sub-stack to reform the stack.

[0053] The method may further comprise the steps of placing and / or removing items from the target container after withdrawing the target container in step (ii) and inserting the target container back into the stack or into a different stack. The target container may be returned to the same stack in the same position from which it was withdrawn (e.g. the target container may be inserted back into the stack before step (iii) is performed) or the target container may be inserted into a different position in the same stack (e.g. by performing step (iii) and repeating step (i) at a different position in the stack). Alternatively, the target container may be inserted into a different stack in the stack processing apparatus.

[0054] The method may further comprise placing an article in the free container prior to inserting the free container between the upper substack and the lower substack.

[0055] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0056] [Figure 1] FIG. 2 is a perspective view of a stack unit comprising a vertical stack of containers located above a stand and a vehicle located below the stand. [Figure 2A] 2 is a sequence illustrating how a vehicle can move under the stand shown in FIG. 1. [Figure 2B] 2 is a sequence illustrating how a vehicle can move under the stand shown in FIG. 1. [Diagram 3] FIG. 2 is an exploded perspective view from above of the container, stand and vehicle, showing how they connect to each other. [Figure 4] FIG. 2 is an exploded perspective view from below of the container, stand and vehicle, showing how they connect to each other. [Figure 5A] 2 is a sequence illustrating how the lifting mechanism of the vehicle moves from a lowered position to a raised position to raise the stand shown in FIG. 1. [Figure 5B] 2 is a sequence illustrating how the lifting mechanism of the vehicle moves from a lowered position to a raised position to raise the stand shown in FIG. 1. [Figure 6] FIG. 1 is a schematic diagram of a storage and retrieval system including a filling station, a storage area, and a picking station. [Figure 7] FIG. 2 is a perspective view of an exemplary filling station. [Figure 8] FIG. 1 is a perspective view of an exemplary storage area. [Figure 9] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 10] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 11] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 12] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 13] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 14] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 15] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 16]1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 17] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 18] 1 is a sequence of diagrams illustrating, in perspective view, a stack handling apparatus operating to extract a target container from a vertical stack of containers. [Figure 19] 9 to 18 further comprising a support member for supporting the stack when the stack is being separated and / or when the target container is being withdrawn. [Figure 20] 9 to 18, further comprising a container processing area and a buffer area. [Figure 21] 19 illustrates the stack processing device of FIGS. 9-18 further comprising an outgoing port and an ingoing port connected by a container path. [Figure 22] 19 illustrates the stack processing device of FIGS. 9-18 further comprising an outgoing port and an ingoing port connected by a container path. [Figure 23] A stack processing station including two stack processing devices of FIGS. 9 to 18 and a container path connecting them is illustrated. [Figure 24] 19 illustrates the stack processing device of FIGS. 9 to 18 further comprising a vision system. [Diagram 25] 1 illustrates another stack processing device. [Figure 26] 26 illustrates the stack processing apparatus of FIG. 25 after receiving a stack of containers. [Figure 27] 26 is a series of diagrams illustrating how the stack processing device of FIG. 25 engages and disengages containers in a stack. [Figure 28] 26 is a series of diagrams illustrating how the stack processing device of FIG. 25 engages and disengages containers in a stack. [Figure 29]26 is a series of diagrams illustrating how the stack processing device of FIG. 25 engages and disengages containers in a stack. [Diagram 30] 26 is a series of diagrams illustrating how the stack processing device of FIG. 25 removes a target container from the stack. [Diagram 31] 26 is a series of diagrams illustrating how the stack processing device of FIG. 25 removes a target container from the stack. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0057] FIG. 1 illustrates a stack of containers 10. The stack of containers 10 comprises a plurality of individual containers 20 stacked vertically directly on top of one another. The containers 20 may comprise cooperating features (e.g., protrusions and recesses) at the top and bottom to allow the containers 20 to be stacked more easily and stably. As shown in FIG. 1, the stack 10 may comprise containers 20 of different heights. The different heights may be predetermined, i.e., the containers forming the stack are selected from a set of containers having a plurality of predetermined heights.

[0058] The stack 10 sits on a stand 30 which elevates the stack 10 above the ground. The stack 10 on the stand 30 combine to form a stack unit 40. The stand 30 (more clearly shown in FIG. 2) comprises a stand top 31 on which the stack 10 sits and legs 32 extending downwardly from each corner of the stand top 31. The stand top 31 and legs 32 define a space 33 below the stand top 31 which is accessible from the side via one or more side openings 34 defined between adjacent legs 32. In the example shown in FIG. 1, the stand top 31 has a rectangular (square) shape with four legs 32 extending downwardly from the corners and a side opening 34 on each side of the stand 30.

[0059] FIG. 1 also shows a vehicle (e.g., AGV or AMR) 50 below the stand 30. The purpose of the vehicle 50 is to pick up and transport the stack unit 40 to different locations. The vehicle 50 includes a drive mechanism configured to enable the vehicle 50 to move in multiple directions. For example, the drive mechanism may be configured to enable the vehicle to move back and forth in at least two orthogonal directions. The drive mechanism may enable the vehicle to rotate about a vertical axis to enable the vehicle to change direction.

[0060] 2A and 2B, the vehicle 50 is dimensioned such that it can enter and occupy the space 33 below the standtop 31 through either of the side openings 34. In particular, the vehicle 50 is dimensioned such that the vehicle 50 can fit completely within the space 33 in the vertical direction. The vehicle 50 is also preferably dimensioned such that it does not extend laterally beyond the standtop 31 when occupying the space 33.

[0061] 3 and 4 are exploded views of the container 20, stand 30, and vehicle 50, showing how they connect to one another using interlocking features. The top of the stand top 31 includes a concave surface 35 for receiving a corresponding protruding surface 25 on the bottom of the container 20 so that the stack 10 rests more securely on the stand 30. The top of the stand top 31 also includes a sloping surface 36 around the perimeter of the concave surface 35, which cooperates with a corresponding sloping surface 26 around the protruding surface 25 of the container 20 to help the container 20 position itself onto the top of the stand 30.

[0062] The top of the vehicle 50 and the bottom of the stand top 31 also include interlocking features. In particular, the top of the vehicle 50 includes an upwardly extending protrusion 51 that interlocks with a corresponding recess 37 on the underside of the stand top 31, thereby allowing the stand 30 to more securely rest on the vehicle 50 when it is being raised.

[0063] 5A and 5B show a lifting mechanism 52 of the vehicle 50 for lifting the stand 30 after the vehicle 50 is placed under the stand top 31. The vehicle 50 comprises a lifting surface 53 (on which the protrusion 51 is located) that is vertically movable with respect to the body of the vehicle 50 between a lowered position and an elevated position. In the lowered position shown in FIG. 5A, the lifting surface 53 is not engaged with the stand 30. In the elevated position shown in FIG. 5B, the lifting surface 53 is engaged with the underside of the stand top 31, and the overall height of the vehicle 50 is increased so that the stand 30 is lifted completely off the ground and is supported only by the lifting surface 53. Once the lifting surface 53 is in the elevated position, the vehicle 50 can transport the stack unit 40 to the desired location. Once the stack unit 40 has been transported to the desired location, the lifting surface 53 can be moved to the lowered position to place the stack unit 40 back on the ground. The vehicle 50 can then move out of the space 33 to a different location (e.g., a different stack unit 40).

[0064] A number of stacking units 40 may form the basis of a storage and retrieval system in which items are stored in containers 20 of the stacking units 40 for later retrieval. Figure 6 is a schematic diagram of a storage and retrieval system comprising a filling station 60, a storage area 70, and a picking station 80. The arrows indicate possible paths of containers 20 through the storage and retrieval system, starting from the filling station 60.

[0065] FIG. 7 illustrates an exemplary filling station 60 (which may be one of multiple filling stations 60) of the storage and retrieval system. At the filling station 60, the items to be stored are placed into empty or partially full containers 20, which are then formed into new stack units 40 or transferred onto existing stack units 40. The containers 20 in a particular stack unit 40 may all hold the same items or may hold different items. A stack unit 40a containing an empty or partially full container 20 is transported by a vehicle 50 to the filling station 60. The filling station 60 includes a robotic de-stacking arm 61 that picks up the container 20 from the top of the stack unit 40a and places it on a conveyor 63. The conveyor 63 transports the container 20 to a filling area 64 where a worker places the items into the container 20. The conveyor then transports the filled container 20 to a robotic stacking arm 62, which picks up the container 20 and places it on top of an existing stack unit 40b or on top of a stand 30 to form a new stack unit 40. A vehicle 50 then moves the stack unit 40b from the filling station 60 to a storage area 70.

[0066] FIG. 8 illustrates an exemplary storage area 70 of a storage and retrieval system with a floor divided into an array of grid cells 71 arranged in orthogonal X and Y directions. While FIG. 8 illustrates the grid cells 71 marked on the floor of the storage area 70 for clarity, in practice the grid cells 71 need not be physically marked on the floor. Each grid cell 71 may be occupied by a stack unit 40 such that when multiple stack units 40 are placed on the grid cell 71, the stack units 40 form a grid pattern. Not all of the grid cells 71 need be occupied at any one time, and there may be unoccupied grid cells 71, groups of unoccupied grid cells 71, and / or rows and / or columns of unoccupied grid cells 71 within the storage area 70. 8, the side openings 34 of the stack units 40 on adjacent grid cells 71 may be aligned to form a first set of open channels extending through the grid pattern of the stack units 40 and a second set of open channels extending through the grid pattern of the stack units 40, whereby the first and second sets of open channels extend at right angles to one another. Because the vehicles 50 can travel "through" the grid pattern of the stack units 40 rather than having to travel around the perimeter of the grid pattern of the stack units 40, the vehicles 50 can use the open channels to more efficiently move to different locations within the storage and retrieval system.

[0067] FIG. 8 further illustrates a container lifting device 73 disposed above the stack units 40 in the storage area 70. The container lifting device 73 comprises one or more container grabbers 74 movable in a vertical X direction and a horizontal Y direction to allow the container grabber 74 to lift a container 20 from the top of a stack unit 40 and place it on top of another stack unit 40. The container grabber 74 comprises a gripping mechanism that can selectively engage features on the top and / or sides of the container 20 to allow the container grabber 74 to releasably hold the container 20. In this illustrated example, movement and support of the container grabber 74 is accomplished by a gantry structure 75. The gantry structure 75 comprises a hoist 76 for moving the container grabber 74 vertically up to lift the container 20 and for moving the container grabber 74 vertically down to lower the container 20. The hoist 76 is movable (e.g., using rollers and tracks) in a horizontal X direction along a first set of horizontal beams 77, which are movable (e.g., using rollers and tracks) in a horizontal Y direction along a second set of horizontal beams 78. The second set of horizontal beams 78 are supported above the stack unit 40 by vertical supports 79. In this manner, the container grabber 74 can be moved to a particular horizontal and vertical position by moving the first set of horizontal beams 77 horizontally relative to the second set of horizontal beams 78, moving the hoist 76 horizontally relative to the first set of horizontal beams 77, and moving the container grabber 74 vertically relative to the hoist 76.

[0068] One of the purposes of the container lifting device 73 is to rearrange the containers 20 within the stack units 40 while the stack units 40 are held within the storage area 70. For example, the container lifting device 73 can move a container 20 from a stack unit 40 in the middle of a group of stack units 40 to a stack unit 40 located at the edge of the group of stack units 40. This allows for a more efficient system since a stack unit 40 at the edge of a group of stack units can be transported by a vehicle 50 more quickly compared to a stack unit 40 in the middle of a group of stack units. Furthermore, in the context of an item ordering system, the container lifting device 73 can rearrange the containers 20 to create a single stack unit 40 (or a minimum number of stack units 40) with containers 20 holding items of one or more orders, thereby minimizing the number of trips taken by the vehicle 50 between the storage area 70 and the picking station 80.

[0069] At the picking station 80, the items are removed from the stack unit 40. The picking station 80 may be similar to the exemplary filling station 60 illustrated in FIG. 7. In particular, when an item is needed from the storage area 70, the stack unit 40 of the container 20 holding the item is transported from the storage area 70 to the picking station 80 by the vehicle 50. At the picking station 80, the container 20 holding the item is removed from the stack unit 40 by the robotic arm and transported by a conveyor to the picking area, where a worker removes one or more items from the container 20 and places them in a delivery container for delivery to the customer. The container 20 is then placed back on the same or a different stack unit 40 by the robotic arm, and the stack unit 40 is transported back to the storage area 70 by the vehicle 50. Alternatively, if one or more containers 20 in the stack unit 40 need to be refilled with items, the stack unit 40 may be transported to the filling station 60.

[0070] In the above-described filling station 60 and picking station 80, destacking and stacking of containers 20 can be performed manually instead of using a robotic arm, and filling and picking of items from containers 20 can be performed using a robotic arm instead of manually.

[0071] In addition to the floor of the storage area 70 being divided into grid cells 71, the floor of the areas surrounding the filling station 60 and the picking station 80 may also be divided into grid cells. The grid cells may act as a coordinate system to provide a unique location reference for the stack units and vehicles 50.

[0072] The movement of the vehicles 50 between the filling stations 60, the storage areas 70, and the picking stations 80 may be controlled by a central control system communicatively coupled to each vehicle. In particular, the central control system comprises a processing unit comprising one or more processors that wirelessly communicate with the vehicles 50 via one or more wireless transmitters and receivers. The processing units may form part of a computing device located in the same physical location as the filling stations 60, the storage areas 70, and the picking stations 80, or they may form part of a remotely located computing device, for example a cloud-based server. The processing unit may command each vehicle 50 to move to a specific target location (for example a specific grid cell reference) in the storage and retrieval system and to raise or lower the lifting mechanism 52. The processing unit may plan a complete route for each vehicle 50 to a target destination and command the movement of each vehicle 50 accordingly, or each vehicle 50 may itself be equipped with a local control system with a local routing system so that each vehicle 50 can plan its own route to the target location once the target location has been sent to the vehicles 50 by the central control system. Each vehicle 50 may also update the central control system with its current location (eg, grid cell reference) and its current state (eg, the state of the lifting mechanism 52).

[0073] The central control system may also include a data store (e.g., a hard disk drive or solid state drive) for storing data regarding one or more of the location of each stack unit 40 (e.g., in terms of grid cell), the containers 20 within each stack unit 40, the position of each container 20 within each stack 10 of each stack unit 40, and the items within each container 20.

[0074] For example, each stack unit 40 may be associated with a unique identifier, e.g., a QR code, a bar code, or an RFID tag, located on each stand 30. In the data store, the unique identifier of each stack unit 40 may be associated with the current location of each stack unit 40. The unique identifier of the stack unit 40 may be read by a suitable reader (e.g., a camera, an optical / laser scanner, or an RFID reader) located at one or more locations in the storage and retrieval system (e.g., the filling station 60, the storage area 70, the picking station 80, and / or any area in between). A processing unit of the central control system may read data from the data store to direct the vehicle 50 to a particular stack unit 40 at a particular location, and write data to the data store to update the data store with the new location of the stack unit 40 after the stack unit 40 has been moved. Each vehicle 50 may also be equipped with a suitable reader to read the unique identifier of the stack unit 40, so that each vehicle 50 can determine that it is moving the correct stack unit 40 as commanded by the central control system. If the vehicle 50 determines that the stack unit 40 at the target location set by the central control system does not match the stack unit 40 expected by the central control system, the vehicle 50 can send an error signal to the central control system, which can then blacklist the target location and prevent any vehicles 50 from being sent to that target location until the discrepancy is resolved.

[0075] Each container 20 may also be associated with a unique identifier, e.g., a QR code, a bar code, or an RFID tag, located on each container 20. In the data store, the unique identifier of each container 20 may be associated with the unique identifier of the respective stack unit 40 in which each container 20 is located. The unique identifier of the container 20 may be read by a suitable reader (e.g., a camera, an optical / laser scanner, or an RFID reader) located at one or more locations in the storage and retrieval system (e.g., the filling station 60, the storage area 70, the picking station 80, and / or any area in between). For example, a reader may be located at the filling station 60 so that the reader can inform the central control system when a new stack unit 40 is formed or when a new container 20 is placed on an existing stack unit 40, so that the container configuration of the new or existing stack unit 40 is updated in the data store. Similarly, a reader may be located at the picking station 80 so that the container configuration of the stack unit 40 can be updated in the data store when the container 20 is removed from the stack unit 40 to enable items within the container 20 to be picked.

[0076] In the data store, the unique identifier for each container 20 may also be associated with the position within the stack of containers 10 in which the container 20 is located. For example, a container 20 at the bottom of the stack of containers 10 may be at position "1," the container 20 at the next higher position may be at position "2," and so on. This information may be communicated to a robotic arm or human operator at the picking station 80 to enable the robotic arm or human operator to know which containers 20 need to be accessed from the stack unit 40 before picking an item.

[0077] The data store may also store data regarding the items stored within each container 20. For example, at the filling station 60, items having a bar code or other identifier may be scanned by an appropriate reader before being placed into a container 20. The reader may communicate with the central control system, allowing the data store to associate the unique identifier of each container 20 with the identifier of each item placed into the container 20. Similarly, at the picking station 80, items picked out of a container 20 may be scanned and communicated to the central control system, so that the contents of the container 20 may be updated in the data store. In this manner, the storage and retrieval system may track the location and quantity of each item within the system.

[0078] The storage and retrieval system may be used in the context of an item ordering system, e.g., an online retail system. When an order comprising an item is received from a customer, a processing unit of the central control system consults the data in the data store to determine the container 20 in which the item resides and the location of the stack unit 40 in which the container 20 resides. The processing unit then commands a vehicle 50 to retrieve the stack unit 40 from the storage area 70 and transport it to a picking station 80. At the picking station 80, the container 20 containing the item is removed from the stack unit 40 so that the item can be picked out of the container 20 and ultimately delivered to the customer. If the order comprises multiple different items, the central control system may command the vehicle 50 to transport all of the required stack units 40 one by one to the picking station 80, or the central control system may command multiple vehicles 50 to transport multiple required stack units 40 to the picking station 80. 8, the container lifting device 73 may be used to rearrange the containers 20 in the storage area 70 such that the containers 20 required for an order are rearranged into a single stack unit 40, or at least rearranged into fewer stack units 40 than the number of containers 20 required. In this way, the vehicles 50 may take fewer trips between the storage area 70 and the picking station 80, thereby increasing the efficiency of the system. To further increase efficiency, multiple orders containing at least some of the same items may also be grouped together, such that one container 20 arriving at the picking station 80 may be used to fulfill multiple orders simultaneously.

[0079] 9 shows a stack processing device 100 that can be used, for example, at the filling station 60 or the picking station 80. The stack processing device 100 can extract containers from and / or insert containers into a vertical stack of containers. The stack can be the stack 10 in the stack unit 40 shown in FIG. 1 or any other vertical stack of containers (e.g., the stack 10 without the stand 30).

[0080] Each container 20 in the stack 10 includes features that allow the container 20 to be engaged and lifted from one or more sides. For example, each container 20 may include one or more openings, recesses, protrusions, rims, etc. Each container 20 is preferably open at the top to allow items to be placed in or removed from the container 20.

[0081] The stack 10 may be transported to the stack processing apparatus 100 by the vehicle 50, as described above. Alternatively, the stack 10 may be transported to the stack processing apparatus 100 using other transport means such as a conveyor (with or without the stand 30) or a manually operated vehicle.

[0082] 9 to 18 show a sequence in which the stack processing device 100 pulls out a target container 21 from the stack 10 of containers. The target container 21 is defined as a container to be pulled out from the stack 10.

[0083] The stack processing apparatus 100 comprises a stack receiving area 110. The stack receiving area 110 is configured to receive a stack of containers 10. The stack receiving area 110 is defined by a columnar frame structure 111 with an opening that allows the stack of containers 10 to be moved into the stack receiving area 110. The frame structure 111 is not limited to any particular shape or configuration, provided that it is capable of supporting various components of the stack receiving area 110, which are described further below.

[0084] FIG. 10 shows the stack handling device 100 when a stack 10 is received in the stack receiving area 110 .

[0085] The stack receiving area 110 includes a stack separation mechanism 112 that includes a separation member 113. The separation member 113 is vertically movable within the stack receiving area 110 to allow the separation member 113 to engage any container 20 in the stack 10. In this example, the separation member 113 is vertically movable on a pair of vertical rails 115 that are attached to one side of a frame structure 111 that defines the stack receiving area 110. The separation member 113 may move on the rails 115 using known means such as a ball screw mechanism or a belt drive. Although a pair of vertical rails 115 are provided for stability, the separation member 113 may alternatively move on a single vertical rail, or on more than two vertical rails.

[0086] The separating member 113 is configured to releasably engage a container 20 in the stack 10 such that, upon engagement, the container 20 may be moved vertically by moving the separating member 113 vertically. The separating member 113 may comprise any suitable mechanism for engaging the container 20. For example, the separating member 113 may comprise one or more engagement features 114 configured to move toward the stack 10 to engage a corresponding feature of the container 20 and move away from the stack 10 to release the corresponding feature of the container 20. The engagement feature 114 may be, for example, one or more protrusions (e.g., extending horizontally toward the stack), recesses, openings, etc. The separating member 113 may comprise one or more actuators for moving the engagement feature toward and away from the stack. The engagement feature 114 may be moved relative to a portion of the separating member 113 or the separating member 113 may move toward and away from the stack 10 as a whole. The actuator may be a linear actuator. The actuator may be any suitable type of actuator, for example pneumatic, hydraulic, electric, etc.

[0087] The stack separating mechanism 112 further comprises a similar second separating member 113 movable on a second pair of vertical rails 115 on opposing sides of the frame structure 111 defining the stack receiving area 110 such that the stack 10 is positioned between the opposing pair of separating members 113. The opposing pair of separating members 113 may be configured to move together vertically and engage a container located therebetween using the engagement features 114 described above. Alternatively, the opposing pair of separating members 113 may act as clamps that frictionally engage opposite sides of the container 20.

[0088] In this example, the separation members 113 are provided in opposing pairs, however, the stack separation mechanism 112 is not limited to this arrangement and may instead have a separation member 113 on only one side of the stack 10 (to cantilever-type engage and lift the container), a non-opposing pair of separation members 113 (e.g., positioned on adjacent sides of the stack), or more than two separation members 113 (e.g., positioned on more than two sides of the stack).

[0089] Once the stack 10 is received in the stack receiving area 110, the stack separating mechanism 112 is operable to vertically move the separating member 113 to a vertical position in the container 22 immediately above the target container 21, as shown in FIG.

[0090] The separating member 113 then engages the container 22 and moves vertically upwards to lift the container 22 (and any containers stacked above it) away from the target container 21. The state of the stack processing apparatus 100 at this point is shown in Figure 12, where it can be seen that the stack 10 has been vertically separated into two sub-stacks 11, an upper sub-stack 11a and a lower sub-stack 11b. The target container 21 is now exposed at the top of the lower sub-stack 11b.

[0091] The stack processing apparatus 100 further comprises a container receiving area 130 horizontally adjacent to the stack receiving area 110. The container receiving area 130 is configured to receive a target container 21 pulled from the stack receiving area 110. In this example, the container receiving area 130, like the stack receiving area 110, is defined by a columnar frame structure 131. The frame structure 131 is not limited to any particular shape or configuration, provided it is capable of supporting various components within the container receiving area 130, which are described further below.

[0092] The container receiving area 130 comprises a container handling mechanism 132 comprising a handling member 133. The handling member 133 is vertically movable within the container receiving area 130 to enable the handling member 133 to reach the vertical position of the target container 21, as shown in FIG. 13. Similar to the separating member 113, the handling member 133 is vertically movable on a pair of vertical rails 135 attached to one side of a frame structure 131 that defines the container receiving area 130. The handling member 133 may move on the rails 135 using known means such as a ball screw mechanism or a belt drive. Although a pair of vertical rails 135 is provided for stability, the handling member 133 may alternatively move on a single vertical rail, or on more than two vertical rails.

[0093] The handling member 133 is also horizontally movable to allow the handling member 133 to engage and horizontally withdraw the target container 21 from the stack 10. In particular, at least a portion of the handling member 133 is horizontally movable between the container receiving area 130 and the stack receiving area 110. In this example, the handling member 133 comprises a retractable arm 136 configured to extend and retract horizontally linearly between the container receiving area 130 and the stack receiving area 110. Figure 14 shows the arm 136 in an extended state in which the arm 136 is in the stack receiving area 110 and adjacent to the target container 21.

[0094] The handling member 133 is configured to releasably engage a target container 21 in the stack 10, such that upon engagement, the target container 21 may be moved vertically and / or horizontally by moving the handling member 133 vertically and / or horizontally, respectively. Similar to the separating member 113, the handling member 133 may comprise any suitable mechanism for engaging the target container 21. For example, the handling member 133 may comprise one or more engagement features 134 configured to move towards the stack 10 to engage corresponding features of the container 20 and move away from the stack 10 to release corresponding features of the container 20. The engagement feature 134 may be, for example, one or more protrusions (e.g., extending horizontally towards the stack), recesses, openings, etc. The handling member 133 may comprise one or more actuators for moving the engagement features towards and away from the stack. The engagement feature 134 may be moved relative to a portion of the handling member 133, or the handling member 133 may be moved towards and away from the stack 10 as a whole. The actuator may be a linear actuator. The actuator may be any suitable type of actuator, for example, pneumatic, hydraulic, electric, etc.

[0095] Similar to the stack separation mechanism 112, the container handling mechanism 132 further comprises a similar second handling member 133 movable on a second pair of vertical rails 135 on opposing sides of the frame structure 131 that defines the container receiving area 130. The opposing pair of handling members 133 may be configured to move together in a vertical direction and to engage a target container 21 therebetween using the engagement features 134 described above.

[0096] In this example, the handling members 133 are provided in opposing pairs, however the container handling mechanism 132 is not limited to this arrangement and may instead have handling members 133 on only one side of the stack 10 (for cantilevered engagement and support of the target container 21), may have a non-opposing pair of handling members 133 (e.g., for engaging adjacent sides of the target container 21), or may have more than two handling members 133 (e.g., for engaging more than two sides of the target container 21).

[0097] When the handling member 133 engages the target container 21, the arm 136 of the handling member 133 is configured to retract from the stack receiving area 110 to the container receiving area 130 in order to pull the target container 21 horizontally from the stack 10 into the container receiving area 130. Figure 15 shows the stack processing apparatus 100 with the target container 21 pulled by the handling member 133 into the container receiving area 130.

[0098] Before moving the target container 21 horizontally out of the stack 10, the handling member 133 may be configured to first move the target container 21 vertically upwards, so as to clear the container below it. This may be necessary, for example, if the containers 20 are provided with interlocking stacking features.

[0099] The container receiving area 130 further comprises a container receiving surface 137 for receiving the target container 21 from the handling members 133 after the target container 21 has been withdrawn from the stack 10. In this example, the container receiving surface 137 is in the form of a receiving conveyor (e.g. a roller conveyor or belt conveyor) that is vertically movable within the container receiving area 130 independently of the handling members 133. The receiving conveyor 137 may move vertically on the same rails 135 as the handling members 133 or on a different rail or set of rails using known means such as a ball screw mechanism or belt drive.

[0100] 16 , the receiving conveyor 137 is configured to move vertically to pick up the target container 21. When the receiving conveyor 137 reaches the target container 21, the handling members 133 are configured to release the target container 21 (e.g., by moving the engagement features 134 away from the target container 21) so that the target container 21 rests freely on the receiving conveyor 137.

[0101] The receiving conveyor 137 may be configured to move vertically towards the vertical position of the target container 21 at any point during operation of the handling member 133. For example, the receiving conveyor 137 may start moving towards the target container 21 only when the target container 21 is fully withdrawn from the stack 10, or the receiving conveyor 137 may start moving towards the handling member 133 when the target container 21 is fully withdrawn from the stack 10 such that the receiving conveyor 137 is already at or near the correct vertical position to receive the target container 21.

[0102] The stack processing apparatus 100 further comprises a container port area 150 horizontally adjacent to the container receiving area 130 for receiving the target container 21 from the container receiving area 130. The container port area 150 comprises a container port 151 configured to receive the target container 21 from the container receiving area 130. The container port 151 comprises a port face 152 capable of receiving the target container 21. The port face 152 may be fixed in a predetermined vertical position, for example at a height convenient for a human operator or a robotic device to access the contents of the target container 21. In this example, the port face 152 is in the form of a conveyor (e.g., a roller conveyor or belt conveyor), although the port face 152 may take other forms, for example, a stationary platform, a manually operated vehicle, an automated guided vehicle, etc.

[0103] As shown in Figure 17, once the receiving conveyor 137 receives the target container 21, the receiving conveyor 137 moves vertically to the port face 152. Once the receiving conveyor 137 is aligned with the port face 152, the receiving conveyor 137 can convey the target container 21 onto the port face 152, as shown in Figure 18. The target container 21 can then be transported from the port face 152 to another destination, for example, by a conveyor, a person, a vehicle, etc.

[0104] Although the container receiving surface 137 described above is vertically movable within the container receiving area 130, the vertical position of the container receiving surface 137 may instead be fixed (e.g. at the same vertical position as the port surface 152) and the handling members 133 may be configured to move vertically towards the container receiving surface 137 before releasing the target container 21. However, in Figs. 9-18 it can be seen that the bottom of the stack 10 is lower than the fixed port surface 152. Thus, by providing a container receiving surface 137 that is vertically movable within the container receiving area 130 (in particular movable below the bottom container in the stack 10), it is possible for the handling members 133 to withdraw any containers below the port surface 152 and lift these containers up to the port surface 152. In the alternative, the stack 10 of containers may be received in the stack processing device 100 such that the bottom of the stack 10 is at the same height as or higher than the port surface 152. In these cases, the container receiving surface 137 does not need to move vertically to allow the handling members 133 to access the containers 20 at the bottom of the stack 10.

[0105] The stack processing apparatus 100 can also function in the reverse manner to insert a free container into the stack. A free container 24 is defined as a container 20 that is to be inserted into the stack 10. Thus, a target container 21 that has been pulled from a stack 10 can be referred to as a free container 24 if it is to be reinserted into the stack 10 or into a different stack 10. A free container 24 may be a container 20 that was not previously part of the stack 10. The free container 24 may arrive at the stack processing apparatus 100 at a container port 151.

[0106] Starting with the state of the stack processing device 100 shown in FIG. 18, several different actions can occur at this point.

[0107] If another target container 21 is to be pulled from the same stack 10 and the next target container 21 happens to be the container currently at the top of the lower sub-stack 11b, the separating member 113 can remain in place and the handling member 133 can move vertically and horizontally to pull the next target container 21 from the stack in the manner already described above.

[0108] If the next target container 21 is located elsewhere in the same stack 10, the separating member 113 may lower the upper sub-stack 11a and release it onto the lower sub-stack 11b to reform the stack 10. The separating member 113 may then perform another separating operation to separate the stack 10 at the appropriate position, allowing the handling member 133 to extract the next target container 21 in the manner already described above.

[0109] If a free container 24 is inserted into the same stack 10 in the same position as the target container 21 was just removed from, the separating member 113 may remain in place while the free container 24 arrives at the container port 151 and is moved onto the receiving conveyor 137 in the container receiving area 130. The handling member 133 may then move vertically up to and engage the free container 24, or the receiving conveyor 137 may move vertically to lift the free container 24 towards the handling member 133 so that the handling member 133 may engage the free container 24. The handling member 133 may then move the free container 24 horizontally into the gap between the upper substack 11a and the lower substack 11b and release the free container 24 onto the lower substack 11b. The separating member 113 may then lower the upper substack 11a and release it onto the inserted free container 24 to reform the stack 10.

[0110] If a free container 24 is to be inserted into the same stack 10 but at a different position than the position from which the target container 21 was just removed, the separating member 113 may first lower the upper sub-stack 11a and release it onto the lower sub-stack 11b to re-form the stack 10. The separating member 113 may then perform another separating operation to separate the stack 10 at the appropriate position to allow the handling member 133 to insert the free container 24 into the desired position within the stack 10.

[0111] Containers 20 may be withdrawn from and / or inserted into the same stack 10 at various different locations in the manner described above until no further action is required on the stack 10. The separating members 113 may then reform the stack 10, which may then be transported away from the stack receiving area 110 to a different location. A vertical stack 10 of different containers may then be transported into the stack receiving area 110 for withdrawal and / or insertion of containers.

[0112] The stack processing device 100 may be configured to only extract target containers 21, only insert free containers 24, or perform both extraction and insertion operations.

[0113] It will be appreciated that if the target container 21 is at the top of the stack 10, there is no need to separate the stack 10 before the handling members 133 extract the target container 21. Similarly, there is no need to separate the stack 10 if a free container 24 is inserted at the top of the stack 10 or at the bottom of the stack 10 (although in the latter case the entire stack 10 needs to be lifted by the separating members 113).

[0114] Various modifications to the stack processing apparatus 100 illustrated in FIGS. 9-18 will be apparent to those skilled in the art.

[0115] For example, the container port area 150 horizontally adjacent the container receiving area 130 is optional. Instead of providing a container port area 150, the target container 21 may be removed directly (e.g., by a person or a vehicle) from a container receiving surface 137 in the container receiving area 130, or the container receiving surface 137 may be part of a vehicle that receives the target container 21 directly from the handling member 133 and transports it to a different location.

[0116] Providing a container receiving surface 137 within the container receiving area 130 is also optional. For example, the handling member 133 may be configured to place and release the target container 21 directly onto the port surface 152 of the container port 151. This may be accomplished by providing a handling member 133 that is horizontally movable between the stack receiving area 110, the container receiving area 130, and the container port area 150. For example, the handling member 133 may include a retractable arm 136 configured to extend from the container receiving area 130 to the stack receiving area 110, and from the container receiving area 130 to the container port area 150.

[0117] The handling member 133 may be vertically movable in the stack receiving area 110 instead of the container receiving area 130. In this variation, the handling member 133 may be vertically movable in the stack receiving area 110 independent of the separating member 113. To withdraw the target container 21 horizontally, the handling member 133 may comprise a retractable arm 136 extending horizontally from the stack receiving area 110 to the container receiving area 130.

[0118] 19 shows a view of the stack receiving area 110 of the stack processing apparatus 100 in which the stack separation mechanism 112 further comprises a support member 118 that is vertically movable within the stack receiving area 110 independent of the separation member 113. The support member 118 is configured to releasably engage a container 20 in the stack using engagement features 119 similar to those already described for the separation member 113 and handling member 133.

[0119] An opposed pair of support members 118 may be provided, as may the separating member 113 and the handling member 133. The support members 118 may be movable on the same vertical rails 115 as the separating member 113, or on different vertical rails, or on partially shared rails.

[0120] One purpose of the support members 118 is to support a container below the target container 21 so as to prevent the container below the target container 21 from being unintentionally lifted or moved with the target container 21 as the target container 21 is being withdrawn by the handling members 133. To this end, the support members 118 are configured to move vertically up to and engage the container 23 immediately below the target container 21, and hold the container 23 in place while the handling members 133 withdraw the target container 21.

[0121] Alternatively or additionally, the support members 118 may support the lower substack 11b so that containers from the lower substack 11b are not unintentionally lifted along with the upper substack 11a when the separating member 113 is lifting the upper substack 11a. To this end, the support members 118 are configured to move vertically up to and engage the target container 21 and hold the target container 21 in place while the separating member 113 separates the stack 10. Once the stack 10 has been separated, the support members 118 may move vertically up to and engage the container 23 immediately below the target container 21 (as described above) to support the container below the target container 21 while the handling member 133 withdraws the target container 21.

[0122] 20 shows the stack processing apparatus 100 further comprising a container processing area 160 configured to receive an unloaded target container 21 from the container port 151. In the container processing area 160, the target container can undergo processing, and articles can be placed in or removed from the target container, for example, by a human or a robotic device. The stack processing apparatus 100 can also comprise a buffer area 161, in which a previously or subsequently unloaded target container 21 can be temporarily stored without blocking the container processing area 160. Containers can be moved between the container port 151, the container processing area 160, and the buffer area 161 using a conveyor arrangement or other transport means.

[0123] 21 illustrates a stack processing apparatus 100 in which a container port area 150 includes two container ports 151: an outgoing port 153 configured to receive a withdrawn target container 21 from the container receiving area 130, and an infeed port 154 configured to receive a free container 24 to be moved into the container receiving area 130 for insertion into the stack 10. The outgoing port 153 is located vertically below the infeed port 154, thereby allowing the target container 21 to exit the container receiving area 130 at one vertical height and the free container 24 to enter the container receiving area 130 at another vertical height.

[0124] In this arrangement, the container receiving surface 137 in the form of a receiving conveyor is vertically movable within the container receiving area 130 at least between the outgoing port 153 and the infeed port 154 to enable the target container 21 received from the handling member 133 to be moved to the outgoing port 153 and to enable the free container 24 received at the infeed port 154 to be moved onto the container receiving surface 137.

[0125] In this arrangement, the outgoing port 153 and the infeed port 154 are connected by a container path 170 that is external to the container receiving area 130, which allows the target container 21 to travel from the outgoing port 153 to the infeed port 154. In this manner, the target container 21 may be pulled from the stack 10 to the outgoing port 153, travel along the container path 170 where it may undergo processing (e.g., items may be removed from the target container 21 or may be placed into the target container 21) and then arrive at the infeed port 154 where the target container 21 (now becoming a free container 24) may be reinserted into the same stack 10 or inserted into a different stack 10 that has arrived at the stack receiving area 110. The container path 170 may comprise a continuous path that allows the containers 20 to proceed uninterrupted from the outgoing port 153 to the ingoing port 154, although during use the containers 20 may stop at one or more locations along the container path 170 for processing (e.g., items may be placed into and / or removed from the container 20). As discussed above in relation to FIG. 20 , one or more container processing areas 160 and / or one or more buffer areas 161 (not shown) may be located on the container path 170. The container path 170 may be configured to automatically transport the containers 20 therealong, for example, the container path 170 may take the form of a conveyor.

[0126] To enable the target container 21 to travel the vertical distance between the outgoing port 153 and the ingoing port 154, the container path 170 comprises a vertical transport means 171 in the form of an inclined conveyor. However, other vertical transport means 171 such as a lifting mechanism (e.g. in the form of a vertically movable section of a conveyor) may be used instead.

[0127] 22 shows a stack processing apparatus 100 in which the container port area 150 includes an outfeed port 153 located vertically below the infeed port 154. In this arrangement, the container receiving surface 137 is not configured to move vertically within the container receiving area 130, but is instead fixed in the same vertical position as the port surface 152 of the outfeed port 153. To efficiently transport containers 20 from the container receiving area 130 to the outfeed port and from the infeed port 154 to the container receiving area 130, the container handling mechanism 132 includes two pairs of vertically arranged handling members 133a, 133b that are vertically movable within the container receiving area independently of each other. The two pairs of handling members 133a, 133b may move vertically on a shared vertical rail or on different vertical rails. One pair of handling members 133a, referred to herein as the "extraction pair", is configured to extract target containers 21 from the stack 10 and transfer them to the container receiving surface 137 for transport to the outgoing port 153. The other pair of handling members 133b, referred to herein as the "insertion pair", is configured to engage free containers 24 from the infeed port 154 and insert them into the stack 10. To avoid collision between the extraction pair 133a and the insertion pair 133b, the insertion pair 133b is located above the extraction pair 133a. At least a portion of the insertion pair 133b is further horizontally movable between the container receiving area 130 and the container port area 150 to enable the insertion pair 133b to engage free containers 24 from the infeed port 154. For example, the insertion pair 133b may include a retractable arm 136 configured to extend in the direction of the container port area 150 and in the direction of the stack receiving area 110.

[0128] It is not essential to have two pairs of handling members 133a, 133b, one for extraction and one for insertion; instead, one pair of handling members 133 can perform both tasks, although this is less efficient. Providing two pairs of handling members 133a, 133b also provides redundancy in case one pair fails. Furthermore, the container receiving surface 137 need not be fixed vertically, but instead may move vertically within the container receiving area 130, similar to the arrangement of FIG. 21.

[0129] The container receiving surface 137 is also optional, and at least a portion of the handling member 133a of the withdrawal pair may be configured to move between the container receiving area 130 and the container port area 150 to move the target container directly to the output port 153.

[0130] 21, the arrangement of FIG. 22 comprises a container path 170 external to the container receiving area 130, connecting the outgoing port 153 to the ingoing port 154. The container path 170 comprises a vertical conveying means 171 in the form of a lifting mechanism for lifting containers from the level of the outgoing port 153 to the level of the ingoing port 154. The lifting mechanism 171 may take the form of, for example, a vertically movable conveyor section. The lifting mechanism 171 may be configured to lift the containers to a height convenient for a human operator to access the contents of the container (e.g., to remove or place items into the container). When the stack 10 comprises containers 20 of different height dimensions, the lifting mechanism 171 may be configured to raise the top of each container to the same vertical position regardless of the height dimension of the container, so that each container is in a consistent vertical position for access by a human operator or other device.

[0131] 21 and 22, the container port area 150 includes an outgoing port 153 located vertically below the infeed port 154, however, the container port area 150 may include other arrangements of container ports 151. For example, the infeed port 154 may be located vertically below the outgoing port 153. In general, the container port area 150 may include a single container port 151 or multiple container ports 151 arranged vertically or arranged in a horizontal plane around the container receiving area. When arranged vertically, the container ports 151 may be located directly above or below each other, or the container ports 151 may be horizontally offset from each other. The container port area 150 may include a single outgoing port 153 and / or a single infeed port 154. The container port area may include a single outgoing port 153 with multiple infeed ports 154, or multiple outgoing ports 153 with a single infeed port 154, or multiple outgoing ports 153 and multiple infeed ports 154. Each outgoing port 153 may be configured to transport a target container 21 to a different location. Each ingoing port 154 may receive a free container 24 from a different location. In an arrangement in which the container ports 151 are arranged in a horizontal plane about the container receiving area, the container receiving surface 137 in the container receiving area 130 may be configured to rotate about a vertical axis to align with each container port 151, or the container receiving surface 137 may be capable of conveying a container in any one of a number of different directions (e.g., orthogonal directions).

[0132] 23 shows an arrangement in which two stack processing apparatus 100 are operatively connected together. In particular, the first stack processing apparatus 100a is configured to extract a target container 21 from the stack 10 and includes an outgoing port 153. The second stack processing apparatus 100b is configured to insert a free container 24 into the stack 10 and includes an infeed port 154. The outgoing port 153 of the first stack processing apparatus 100a is connected to the infeed port 154 of the second stacking apparatus 100b by a container path 170 (e.g., a conveyor) so that the target container 21 extracted by the first stack processing apparatus 100a can be fed as a free container 24 to the second stacking processing apparatus 100b.

[0133] The containers may undergo processing as they proceed along the container path 170. For example, items may be removed from or inserted into the container by a human or robotic device. The container path 170 may include one or more container processing areas 160 where the containers may stop to allow items to be removed from or inserted into the container. The container path 170 may include one or more buffer areas 161 for temporary storage of the containers without blocking the path between the two stack processing devices 100a, 100b.

[0134] 24 shows the stack processing apparatus 100 further comprising a first container recognition system 181 configured to determine the vertical position of one or more containers 20 in the stack 10. The container recognition system 181 may be part of a control system 180 for controlling the vertical movement of the separating member 113 and the handling member 133.

[0135] In this example, the container recognition system 181 is in the form of a vision system 181 comprising a camera 182 configured to capture one or more images of the stack 10 of containers as the stack 10 approaches the stack receiving area 110. The one or more processors are then configured to analyze the images of the stack 10 to determine the vertical position of one or more containers 20 within the stack 10 such that the one or more processors of the control system 180 can command the separating member 113 and the handling member 133 to move vertically to an appropriate vertical position to enable the stack 10 to be separated in the correct position and the target container 21 to be extracted.

[0136] For example, each container 20 may be provided with a visual identifier (e.g., a barcode or QR code) that can be recognized by the vision system 181. Additionally, the control system 180 may include a data store that includes data relating the visual identifier of the container 20 to a height dimension of the container 20. Thus, by recognizing each container 20 in the stack 10 and using the data regarding their height dimension, the control system 180 can determine the vertical distance that the separating members 113 and handling members 133 need to travel to perform their respective functions.

[0137] Alternatively, one or more processors of the vision system 181 may be configured to perform image processing and image analysis techniques, such as edge detection, to determine the vertical position of one or more containers 20 within the stack 10.

[0138] Instead of capturing an image of the stack 10 when the stack 10 approaches the stack receiving area 110, the camera 182 may be configured to capture one or more images of the stack 10 when the stack 10 is within the stack receiving area 110.

[0139] Instead of capturing images of the entire stack 10, the camera 182 may be configured to move vertically within the stack receiving area 110 and capture images of the sides of the containers 20 as the camera 182 progresses up and down the stack 10. The camera 182 may move vertically together with the separating members 113 or independently of the separating members 113. Once the processor or processors recognize a target container 21 (via the visual identifiers discussed above), the control system 180 can move the separating members 113 and handling members 133 appropriately to perform their respective functions.

[0140] The container recognition system 181 may alternatively be in the form of an RFID system, where each container 20 is provided with an RFID tag and the control system 180 is provided with an RFID reader. The RFID reader may be configured to read the RFID tags of the containers 20 in the stack 10 as the stack 10 approaches the stack receiving area 110, or the RFID reader may be configured to move vertically within the stack receiving area 110 and read the RFID tag of each container 20 as the RFID reader progresses up and down the stack 10. The RFID reader may move vertically together with the separating member 113 or independently of the separating member 113. Once the RFID reader recognizes the target container 21, the control system 180 can move the separating member 113 and the handling member 133 appropriately to perform their respective functions.

[0141] The container identifier (e.g., a barcode, QR code, RFID tag, etc.) may uniquely identify the container 20 or may identify the type of container 20 (e.g., the same identifier may apply to all containers having a particular dimension).

[0142] If the containers 20 all have the same dimensions, a container recognition system may not be necessary. In this case, the control system 180 only needs to know the relative position of the target container 21 in the stack (e.g., the third container from the bottom) and the predetermined height dimension of the container 20 in order to move the separating members 113 and handling members 133 to the appropriate vertical positions for extracting the target container 21.

[0143] FIG. 24 also shows a second container recognition system 185 in the container port area 150 configured to recognize containers entering the container port 151. In particular, the container recognition system 185 comprises an outgoing camera 186 configured to recognize a target container entering the outgoing port 153 and an ingoing camera 187 configured to recognize a target container entering the ingoing port 154. The outgoing camera 186 and the ingoing camera 187 may be configured to recognize the containers in the same manner as the first container recognition system 181 described above (i.e., via an identifier on each container). The second container recognition system 185 allows the control system 180 to double-check that the correct target container 21 has been pulled from the stack 10 and to double-check the free container 24 to be inserted into the stack. The second container recognition system 185 may also be configured to check the contents of each container (e.g., using image recognition techniques) as the container enters the container port 151.

[0144] Similar to the first container recognition system 181, the second container recognition system 185 may use alternative methods of recognizing containers, such as RFID tags and readers. The second container recognition system 185 may also be located in the container receiving area instead of the container port area to recognize containers entering the container receiving area.

[0145] The container recognition systems 181, 185 are not limited to use with the stack processing device 100, but may be used with any of the stack processing devices described herein.

[0146] FIG. 25 shows a stack processing apparatus 200 that functions similarly to the stack processing apparatus 100 of FIGS. 9-18 in that it is capable of withdrawing a target container 21 from and / or inserting a free container 24 into a vertical stack 10 of containers. However, instead of separating the stack 10 into two sub-stacks 11 (an upper sub-stack and a lower sub-stack), the stack processing apparatus shown in FIG. 25 is capable of separating the stack into more than two sub-stacks. By separating the stack 10 into more than two sub-stacks, more than one target container 21 can be withdrawn from the separated stack 10 and / or more than one free container 24 can be inserted into the separated stack 10 without the need to re-form the stack 10 between each withdrawal or insertion operation.

[0147] Similar to stack processing apparatus 100, stack processing apparatus 200 comprises a stack receiving area 210 for receiving a vertical stack 10 of containers. In contrast to stack processing apparatus 100, stack receiving area 210 is not defined within a columnar frame structure, but instead is defined in part by a frame structure 211 located on one side of stack receiving area 210. Figure 26 shows a vertical stack 10 of containers inside stack receiving area 210 with frame structure 211 located on one side of stack 10.

[0148] FIG. 27 shows a side view of the stack 10 and the frame structure 211. The stack receiving area 210 includes a stack separation mechanism 212 including a plurality of vertically arranged separation members 213 that are vertically movable within the stack receiving area 210 independently of one another. The separation members 213 are movable on vertical rails 215 (visible in FIG. 25) supported by the frame structure 211. The separation members 213 may be vertically movable on the rails 215 independently of one another using known mechanisms. For example, the vertical rails 215 may be stationary and each separation member 213 may include a motor configured to move the separation member 213 along the rails 215. The vertical rails 215 may include electrical wires in contact with the separation members 213 to provide power to the motors.

[0149] Similar to the stack processing apparatus 100, each separation member 213 is configured to releasably engage a container 20 in the stack 10. The separation members 213 may include any suitable mechanism for engaging features of the container 20, as previously described in relation to the stack processing apparatus 100.

[0150] In this example, the separating members 213 are provided on only one side of the stack receiving area 210, however, the separating members 213 may be arranged in opposing pairs, similar to the stack processing apparatus 100.

[0151] 27 and 28 show the separating members 213 moving from a release position to an engagement position to engage each container 20 in the stack 10. As shown in these figures, the stack receiving area 210 includes sufficient separating members 213 to engage all containers 20 in the stack 10. The number of separating members 213 preferably corresponds to at least the maximum number of stacked containers 20 that the stack processing device 200 is designed to receive and process.

[0152] 29, when the separating members 213 engage all of the containers 20 in the stack 10, the separating members 213 vertically lift all of the containers 20 relative to one another, such that each individual container 20 is vertically spaced apart from the containers 20 immediately above and below it. The stack 10 can now be considered to be separated into a plurality of sub-stacks 11, with each sub-stack 11 containing only one container 20.

[0153] Similar to the stack processing device 100, the stack processing device 200 comprises a container receiving area 230 with handling members 233, as shown in Fig. 30. In contrast to the container receiving area 130 of the stack processing device 100, the container receiving area 230 is not defined by a frame structure and can be considered as an area horizontally adjacent to the stack receiving area 210 into which the target container 21 is drawn.

[0154] The handling member 233 is vertically movable to enable the handling member 233 to reach the vertical position of any container 20 in the stack 10 after separation. The handling member 233 is vertically movable on vertical rails 235 supported by the frame structure 211. The handling member 233 may move on the vertical rails 235 using known means, as already described with respect to the handling member 133 of the stack processing apparatus 100.

[0155] Similar to the handling member 133 of the stack processing apparatus 100, the handling member 233 is configured to releasably engage a target container 21 in a separated stack 10 and may include any suitable mechanism for engaging features of the target container 21, as already described with respect to the handling member 133.

[0156] As shown in FIG. 30, the separating member 213 is located on one side of the stack receiving area 210 to engage one side of a container 20 in the stack 10, and the handling member 233 extends along an adjacent side of the stack receiving area 210 to engage an adjacent side of a container 20 in the stack 10.

[0157] The separating member 213 engaging the target container 21 is configured to release the target container 21 when the handling member 233 moves vertically to and engages the vertical position of the target container 21 .

[0158] At least a portion of the handling member 233 is horizontally movable towards and away from the stack receiving area 210 to enable the handling member 233 to horizontally withdraw the target container 21 from the stack 10. As shown in Figures 30 and 31, the handling member 233 is pivotally mounted for horizontal movement about a vertical axis, in contrast to the linear horizontal movement of the handling member 133 of the stack processing apparatus 100. In this example, the handling member 233 can be pivotally moved through 90 degrees, such that when the handling member 233 engages the target container 21 (and the separating member 213 releases the target container 21), the pivoting movement of the handling member 233 pivots the target container 21 from the stack 10 along a horizontal plane into the container receiving area 230.

[0159] As the target container 21 is withdrawn from the stack 10, the handling member 233 is configured to move vertically to place and release the target container 21 onto a container receiving surface 237 located in the container receiving area 230. In this example, the container receiving surface 237 is in the form of a receiving conveyor 237 (visible in FIG. 25 ). The receiving conveyor 237 is in a fixed vertical position, however, as described with respect to the container receiving surface 137 of the stack processing apparatus 100, the container receiving surface 237 may be configured to move vertically within the container receiving area 230.

[0160] Similar to the stack processing device 100, the stack processing device 200 can be considered to have a container port area 250 horizontally adjacent to the container receiving area 230. As shown in FIG. 25, the container port area 250 includes an outgoing port 253 configured to receive a target container 21 from the container receiving area 230, and an infeed port 254 configured to receive a free container 24 to be moved into the container receiving area 230. In this example, the outgoing port 253 and the infeed port 254 are arranged in a horizontal plane around the container receiving area 230. The outgoing port 253 is connected to the infeed port 254 by a container path 270 that is external to the container receiving area 230, along which the target container 21 can proceed from the outgoing port 253 to the infeed port 254 for reinsertion into the same stack 10 or a different stack 10. In this example, the container path 270 is in the form of a conveyor 270. The target container 21 may undergo processing while traveling along the container path 270, for example items may be placed into or removed from the target container, and the container path 270 may include container processing areas and / or buffer areas, as already described above with respect to the container path 170.

[0161] While the stack 10 is being separated, the handling member 233 may successively withdraw multiple target containers 21 using the same process described above.

[0162] The stack processing apparatus 200 may also function in the reverse manner to insert a free container 24 into any position within the stack 10. In particular, when a target container 21 is withdrawn from the stack 10, the separating members 213 may be held in place while the handling members 233 engage a free container 24 received in the container receiving area 230. The handling members 233 may then insert a free container 24 into the space left by the withdrawn target container 21, and the separating members 213 previously engaged with the withdrawn target container 21 may now engage the inserted free container 24. The handling members 233 may then release the free container 24, and the separating members 213 may move vertically together to reform the stack 10.

[0163] If the free container 24 has a different height dimension than the extracted target container 21, the separating members 213 can adjust their vertical positions to provide an appropriately sized space for inserting the free container 24.

[0164] The free containers 24 do not necessarily need to be engaged by the separating members 213 after being inserted into the stack. Instead, the free containers 24 may be placed on top of the containers 20 in the stack 10, provided that each separating member 213 has sufficient strength to hold the weight of more than one container 20.

[0165] When multiple target containers 21 are extracted from the stack 10, multiple free containers 24 may be inserted into the space left by the extracted target containers 21 before the stack 10 is reformed.

[0166] In this example, the stack separation mechanism 212 has sufficient separation members 213 to engage and lift all containers in the stack, but this is not required and the stack separation mechanism 212 may have at least two separation members 213 to separate the stack 10 into more than two sub-stacks 11 containing one or more containers 20.

[0167] It will be understood that features of stack processing apparatus 200 can be combined with features of stack processing apparatus 100, and vice versa. For example, the features of the stack receiving areas 110, 210, container receiving areas 130, 230, container port areas 150, 250, and container paths 170, 270 described in connection with stack processing apparatus 100, 200 are not intended to be unique to those stack processing apparatuses, but instead can be combined in any combination to form a stack processing apparatus suitable for withdrawing containers from and / or inserting containers into a stack.

[0168] One or more stack handling devices 100, 200 may form part of a wider storage and retrieval system in which items are stored in containers arranged into a vertical stack 10, such as the system described in relation to Figures 6-8. The storage and retrieval system may comprise a picking station where items are removed from individual containers, for example to fulfil customer orders. The picking station may comprise stack handling devices 100, 200 arranged to extract a target container from the stack 10 so that the items in the target container can be removed. The stack handling devices 100, 200 may also be arranged to return the extracted container to the stack. The arrangement shown in Figures 20-23 may for example be used as a picking station. The storage and retrieval system may also comprise a filling station where empty containers are filled with items to be stored. The filling station may comprise stack handling devices 100, 200 arranged to insert the filled container into an existing stack 10 or to form a new stack 10. The stacks 10 in the system may be in the form of stack units 40 as described above, and the storage and retrieval system may further comprise one or more vehicles 50 as described above.

Claims

1. 1. A stack handling apparatus for moving containers out of and / or into a vertical stack of containers, comprising: a stack receiving area for receiving a vertical stack of containers; a stack separation mechanism comprising a separation member configured to releasably engage a container in the stack, wherein the separation member is vertically movable within the stack receiving area to enable the separation member to engage any container in the stack and vertically lift the engaged container to separate the stack into an upper sub-stack and a lower sub-stack to expose a target container at an upper portion of the lower sub-stack; a container handling mechanism comprising a handling member configured to releasably engage the target container in the stack, wherein the handling member is vertically movable relative to the stack receiving area and horizontally movable to enable the handling member to engage and horizontally withdraw the target container from the stack and / or function in a reverse manner to insert a free container into the stack. A stack processing device comprising:

2. 2. The stack handling device of claim 1, wherein at least a portion of the handling member is horizontally linearly movable towards and away from the stack receiving area.

3. 3. The stack handling apparatus of claim 1 or 2, wherein the handling member comprises a retractable arm configured to extend and retract horizontally linearly towards and away from the stack receiving area.

4. 2. The stack handling apparatus of claim 1, wherein at least a portion of the handling member is pivotally mounted for horizontal movement towards and away from the stack receiving area.

5. 2. The stack processing device of claim 1, wherein at least a portion of the separating member and / or at least a portion of the handling member are movable towards and away from the stack to engage and release containers in the stack, respectively.

6. 2. The stack processing device of claim 1, wherein the stack separation mechanism comprises a pair of horizontally opposed separation members configured to engage a container therebetween, and / or the container handling mechanism comprises a pair of horizontally opposed handling members configured to engage a container therebetween.

7. 2. The stack processing device of claim 1, further comprising a container receiving area horizontally adjacent to the stack receiving area, the handling member being vertically movable within the container receiving area and horizontally movable between the container receiving area and the stack receiving area to extract the target container from the stack into the container receiving area and / or insert a free container from the container receiving area into the stack.

8. 8. The stack processing device of claim 7, further comprising a container port area horizontally adjacent to the container receiving area, the container port area comprising a container port configured to receive a target container from the container receiving area and / or to receive a free container to be moved to the container receiving area.

9. 9. The stack processing apparatus of claim 8, wherein the container port area comprises a plurality of container ports arranged vertically or in a horizontal plane about the container receiving area.

10. 10. A stack processing device as claimed in claim 8 or 9, wherein the handling member is horizontally movable between the container receiving area and the container port area to enable the handling member to move the target container from the container receiving area to one or more of the container ports and / or move a free container from one or more of the container ports to the container receiving area.

11. 11. The stack processing device of claim 10, wherein the container handling mechanism comprises a plurality of vertically arranged handling members, each of which is vertically movable within the container receiving area independently of the other handling members, and at least one of the plurality of handling members is horizontally movable between the container receiving area and the container port area.

12. 10. The stack processing device of claim 9, wherein at least one of the container ports is an outgoing port configured to receive the target container from the container receiving area, and at least one of the container ports is an ingoing port configured to receive a free container to be moved to the container receiving area.

13. 13. The stack processing apparatus of claim 12, wherein the outgoing port is connected to the ingoing port by a container path external to the container receiving area, along which the target container can travel from the outgoing port to the ingoing port.

14. 14. The stack processing apparatus of claim 13, wherein the outgoing port and the inflow port are vertically disposed, and the container path comprises a vertical transport means configured to move containers from a height of the outgoing port to a height of the inflow port.

15. 9. The stack processing apparatus of claim 8, wherein the container receiving area further comprises a container receiving surface configured to receive the target container from the handling member, deliver the target container to any one of the container ports, and / or receive a free container from any one of the container ports for insertion into the stack by the handling member.

16. 16. The stack processing apparatus of claim 15, wherein the container receiving surface is vertically movable within the container receiving area independently of the handling members.

17. 9. The stack processing device of claim 8, further comprising a container processing area configured to receive the target container from the container port to allow items to be moved out of or into the container.

18. 18. The stack processing apparatus of claim 17, further comprising a buffer area for temporarily storing one or more containers without blocking the container processing area.

19. 2. The stack processing device of claim 1, wherein the stack separation mechanism further comprises a support member configured to releasably engage a container in the stack, the support member being vertically movable within the stack receiving area and configured to engage a container in the lower sub-stack while the separation member is separating the stack and / or while the handling member is withdrawing the target container.

20. 2. The stack processing device of claim 1, further comprising a control system comprising a container recognition system configured to determine a vertical position of one or more containers in the stack, the control system configured to vertically move the separating member and / or the handling member based on the determined vertical position.

21. 2. The stack processing device of claim 1, wherein the stack separation mechanism comprises a plurality of vertically disposed separation members that are vertically movable within the stack receiving area independently of one another to allow the vertically disposed separation members to move into and engage a plurality of containers in the stack and vertically lift the engaged containers relative to one another to separate the stack into more than two sub-stacks.

22. 22. The stack processing apparatus of claim 21, wherein the stack receiving area is configured to receive a predetermined maximum number of vertically stacked containers, and the number of vertically disposed separating members is at least equal to the predetermined maximum number of vertically stacked containers to enable the vertically disposed separating members to move into and engage all containers in the stack and vertically lift all containers relative to one another to separate the stack into multiple sub-stacks, each sub-stack including only one container.

23. A stack processing station comprising: A first stack processing apparatus according to claim 1 ; A second stack processing device according to claim 1; Equipped with A stack processing station, wherein the first stack processing device is connected to the second stack processing device to enable a target container pulled from a stack in the first stack processing device to proceed to the second stack processing device for insertion into a stack in the second stack processing device.

24. 1. A stack processing system comprising: one or more vertical stacks of containers; One or more stack processing devices according to claim 1 or one or more stack processing stations according to claim 23; A stack processing system comprising:

25. 13. A method of processing a vertical stack of containers using the stack processing apparatus of claim 1, comprising the steps of: (i) vertically lifting containers within the stack to separate the stack into an upper sub-stack and a lower sub-stack; (ii) horizontally withdrawing a target container from the stack on top of the lower substack, and / or horizontally inserting a free container between the upper substack and the lower substack; (iii) lowering the upper sub-stack onto the lower sub-stack to reform the stack; A method comprising the steps of:

26. 26. The method of claim 25, further comprising the step of placing and / or removing items from the target container after removing the target container in step (ii) and inserting the target container back into the stack or a different stack.

Images