WO2024246295A1

WO2024246295A1 - A container transfer station for buffering storage containers in an automated storage and retrieval system

Info

Publication number: WO2024246295A1
Application number: PCT/EP2024/065051
Authority: WO
Inventors: Mats Haugen GAUSDAL
Original assignee: Autostore Technology AS
Priority date: 2023-06-01
Filing date: 2024-05-31
Publication date: 2024-12-05
Also published as: NO20230627A1; NO348399B1

Abstract

The invention relates to a container transfer station for transferring a stack of storage containers from an automated storage and retrieval system to a location outside the system. The container transfer station comprises a vertical framework structure that is arranged along the outside of a port column leading from the automated storage and retrieval system. The framework also includes a pair of releasable latch mechanism with plurality of latches. The plurality of latches further includes a pair of latches aligned vertically and arranged on an inner opposite wall of the vertical framework and configured to operate in a carousel movement. The releasable latch mechanism controls the operation of the pair of latches to latch and release individual storage containers from the stack of containers within the vertical framework. The container transfer station also comprises a container support arranged at the lower level of the framework and configured to support a lowermost container from the stack that is released from the releasable latch mechanism. The lowermost container is further transported away from the container transfer station by the container support to the location outside the framework. The container may then be accessed by a human or a robotic operator.

Description

A container transfer station for buffering storage containers in an automated storage and retrieval system

FIELD OF THE INVENTION

The present invention relates to a container transfer station in an automated storage and retrieval system, in particular to a transfer station and a method for employing the transfer station for buffering storage containers.

BACKGROUND AND PRIOR ART

Fig. 1 discloses a prior art automated storage and retrieval system 1 with a framework structure 100 and Figs. 2, 3 and 4 disclose three different prior art container handling vehicles 200,300,400 suitable for operating on such a storage and retrieval system 1.

The framework structure 100 comprises upright members 102 and a storage volume comprising storage columns 105 arranged in rows between the upright members 102. In these storage columns 105 storage containers 106, also known as bins, are stacked one on top of one another to form stacks 107. The upright members 102 may typically be made of metal, e.g. extruded aluminum profiles.

The framework structure 100 of the automated storage and retrieval system 1 comprises a rail system 108 arranged across the top of framework structure 100, on which rail system 108 a plurality of container handling vehicles 200,300,400 may be operated to raise storage containers 106 from, and lower storage containers 106 into, the storage columns 105, and also to transport the storage containers 106 above the storage columns 105. The rail system 108 comprises a first set of parallel rails 110 arranged to guide movement of the container handling vehicles 200,300,400 in a first direction X across the top of the frame structure 100, and a second set of parallel rails 111 arranged perpendicular to the first set of rails 110 to guide movement of the container handling vehicles 200,300,400 in a second direction Y which is perpendicular to the first direction X. Containers 106 stored in the columns 105 are accessed by the container handling vehicles 200,300,400 through access openings 112 in the rail system 108. The container handling vehicles 200,300,400 can move laterally above the storage columns 105, i.e. in a plane which is parallel to the horizontal X-Y plane.

The upright members 102 of the framework structure 100 may be used to guide the storage containers during raising of the containers out from and lowering of the containers into the columns 105. The stacks 107 of containers 106 are typically self- supporting.

Each prior art container handling vehicle 200,300,400 comprises a vehicle body 200a, 300a, 400a and first and second sets of wheels 201b, 201c, 301b, 301c, 401b, 401c which enable the lateral movement of the container handling vehicles 200,300,400 in the X direction and in the Y direction, respectively. In Figs. 2, 3 and 4 two wheels in each set are fully visible. The first set of wheels 201b, 301b, 401b is arranged to engage with two adjacent rails of the first set 110 of rails, and the second set of wheels 201c, 301c, 401c is arranged to engage with two adjacent rails of the second set 111 of rails. At least one of the sets of wheels 201b, 201c, 301b, 301c, 401b, 401c can be lifted and lowered, so that the first set of wheels 201b, 301b, 401b and/or the second set of wheels 201c, 301c, 401c can be engaged with the respective set of rails 110, 111 at any one time.

Each prior art container handling vehicle 200,300,400 also comprises a lifting device for vertical transportation of storage containers 106, e.g. raising a storage container 106 from, and lowering a storage container 106 into, a storage column 105. The lifting device comprises one or more gripping / engaging devices which are adapted to engage a storage container 106, and which gripping / engaging devices can be lowered from the vehicle 200,300,400 so that the position of the gripping / engaging devices with respect to the vehicle 200,300,400 can be adjusted in a third direction Z which is orthogonal the first direction X and the second direction Y. Parts of the gripping device of the container handling vehicles 300,400 are shown in Figs. 3 and 4 indicated with reference number 304,404. The gripping device of the container handling device 200 is located within the vehicle body 201a in Fig. 2 and is thus not shown.

Conventionally, and also for the purpose of this application, Z=1 identifies the uppermost layer available for storage containers below the rails 110,111, i.e. the layer immediately below the rail system 108, Z=2 the second layer below the rail system 108, Z=3 the third layer etc. In the exemplary prior art disclosed in Fig. 1, Z=8 identifies the lowermost, bottom layer of storage containers. Similarly, X=l ...n and Y=l ...n identifies the position of each storage column 105 in the horizontal plane. Consequently, as an example, and using the Cartesian coordinate system X, Y, Z indicated in Fig. 1, the storage container identified as 106’ in Fig. 1 can be said to occupy storage position X=17, Y=l, Z=6. The container handling vehicles 200,300,400 can be said to travel in layer Z=0, and each storage column 105 can be identified by its X and Y coordinates. Thus, the storage containers shown in Fig. 1 extending above the rail system 108 are also said to be arranged in layer Z=0.

The storage volume of the framework structure 100 has often been referred to as a grid 104, where the possible storage positions within this grid are referred to as storage cells. Each storage column may be identified by a position in an X- and Y- direction, while each storage cell may be identified by a container number in the X-, Y- and Z-direction.

Each prior art container handling vehicle 200,300,400 comprises a storage compartment or space for receiving and stowing a storage container 106 when transporting the storage container 106 across the rail system 108. The storage space may comprise a cavity arranged internally within the vehicle body 200a, 400a as shown in Figs. 2 and 4 and as described in e.g. WO2015/193278A1 and WO20 19/206487 Al, the contents of which are incorporated herein by reference.

Fig. 3 shows an alternative configuration of a container handling vehicle 300 with a cantilever construction. Such a vehicle is described in detail in e.g. NO317366, the contents of which are also incorporated herein by reference.

The cavity container handling vehicle 200 shown in Fig. 2 may have a footprint that covers an area with dimensions in the X and Y directions which is generally equal to the lateral extent of a storage column 105, e.g. as is described in WO2015/193278A1, the contents of which are incorporated herein by reference. The term ‘lateral’ used herein may mean ‘horizontal’.

Alternatively, the cavity container handling vehicles 400 may have a footprint which is larger than the lateral area defined by a storage column 105 as shown in Fig. 1 and 4, e.g. as is disclosed in W02014/090684A1 or WO2019/206487 Al.

The rail system 108 typically comprises rails with grooves in which the wheels of the vehicles run. Alternatively, the rails may comprise upwardly protruding elements, where the wheels of the vehicles comprise flanges to prevent derailing. These grooves and upwardly protruding elements are collectively known as tracks. Each rail may comprise one track, or each rail 110,111 may comprise two parallel tracks. In other rail systems 108, each rail in one direction (e.g. an X direction) may comprise one track and each rail in the other, perpendicular direction (e.g. a Y direction) may comprise two tracks. Each rail 110,111 may also comprise two track members that are fastened together, each track member providing one of a pair of tracks provided by each rail.

WO2018/146304A1, the contents of which are incorporated herein by reference, illustrates a typical configuration of a rail system 108 comprising rails and parallel tracks in both X and Y directions.

In the framework structure 100, a majority of the columns are storage columns 105, i.e. columns 105 where storage containers 106 are stored in stacks 107. In addition to storage columns 105, there are special -purpose columns within the framework structure. In the example shown in Fig. 1, columns 119 and 120 are such specialpurpose columns used by the container handling vehicles 200,300,400 to drop off and/or pick up storage containers 106 so that they can be transported to an access station (not shown) where the storage containers 106 can be accessed from outside of the framework structure 100 or transferred out of or into the framework structure 100. Within the art, such a location is normally referred to as a ‘port’ and the column in which the port is located may be referred to as a ‘port column’ 119,120. The transportation to the access station may be in any direction, that is horizontal, tilted and/or vertical. For example, the storage containers 106 may be placed in a random or dedicated column 105 within the framework structure 100, then picked up by any container handling vehicle and transported to a port column 119,120 for further transportation to an access station. The transportation from the port to the access station may require movement along various different directions, by means such as delivery vehicles, trolleys or other transportation lines. Note that the term ‘tilted’ means transportation of storage containers 106 having a general transportation orientation somewhere between horizontal and vertical.

In Fig. 1, the first port column 119 may for example be a dedicated drop-off port column where the container handling vehicles 200,300,400 can drop off storage containers 106 to be transported to an access station, and the second port column 120 may be a dedicated pick-up port column where the container handling vehicles 200,300,400 can pick up storage containers 106 that have been transported from an access station.

The access station may typically be a picking or a stocking station where product items are removed from or positioned into the storage containers 106. In a picking or a stocking station, the storage containers 106 are normally not removed from the automated storage and retrieval system 1, but are returned into the framework structure 100 again once accessed. A port can also be used for transferring storage containers to another storage facility (e.g. to another framework structure or to another automated storage and retrieval system), to a transport vehicle (e.g. a train or a lorry), or to a production facility.

A conveyor system comprising conveyors is normally employed to transport the storage containers between the port columns 119,120 and the access station.

If the port columns 119,120 and the access station are located at different levels, the conveyor system may comprise a lift device with a vertical component for transporting the storage containers 106 vertically between the port column 119,120 and the access station.

The conveyor system may be arranged to transfer storage containers 106 between different framework structures, e.g. as is described in WO2014/075937A1, the contents of which are incorporated herein by reference.

When a storage container 106 stored in one of the columns 105 disclosed in Fig. 1 is to be accessed, one of the container handling vehicles 200,300,400 is instructed to retrieve the target storage container 106 from its position and transport it to the dropoff port column 119. This operation involves moving the container handling vehicle 200,300,400 to a location above the storage column 105 in which the target storage container 106 is positioned, retrieving the storage container 106 from the storage column 105 using the container handling vehicle’s 200,300,400 lifting device (not shown), and transporting the storage container 106 to the drop-off port column 119. If the target storage container 106 is located deep within a stack 107, i.e. with one or a plurality of other storage containers 106 positioned above the target storage container 106, the operation also involves temporarily moving the one or plurality of storage containers positioned above the target storage container a prior to lifting the target storage container 106 from the storage column 105. This step, which is sometimes referred to as “digging” within the art, may be performed with the same container handling vehicle that is subsequently used for transporting the target storage container to the drop-off port column 119, or with one or a plurality of other cooperating container handling vehicles. Alternatively, or in addition, the automated storage and retrieval system 1 may have container handling vehicles 200,300,400 specifically dedicated to the task of temporarily removing storage containers 106 from a storage column 105. Once the target storage container 106 has been removed from the storage column 105, the temporarily removed storage containers 106 can be repositioned into the original storage column 105. However, the removed storage containers 106 may alternatively be relocated to other storage columns 105.

When a storage container 106 is to be stored in one of the columns 105, one of the container handling vehicles 200,300,400 is instructed to pick up the storage container 106 from the pick-up port column 120 and transport it to a location above the storage column 105 where it is to be stored. After any storage containers 106 positioned at or above the target position within the stack 107 have been removed, the container handling vehicle 200,300,400 positions the storage container 106 at the desired position. The removed storage containers 106 may then be lowered back into the storage column 105 or relocated to other storage columns 105.

For monitoring and controlling the automated storage and retrieval system 1, e.g. monitoring and controlling the location of respective storage containers 106 within the framework structure 100, the content of each storage container 106, and the movement of the container handling vehicles 200,300,400 so that a desired storage container 106 can be delivered to the desired location at the desired time without the container handling vehicles 200,300,400 colliding with each other, the automated storage and retrieval system 1 comprises a control system 109 which typically is computerized and which typically comprises a database for keeping track of the storage containers 106.

In current storage systems, storage containers are delivered by container handling vehicles 200,300,400 through the port columns 105 by their container lifting and gripping mechanisms. While one container handling vehicle 200,300,400 is delivering a container through the port column 119, the port column 119 is occupied and not available for other container handling vehicles 200,300,400. The remaining container handling vehicles 200,300,400 will need to wait in queue for their turn to deliver containers. In a large storage system, with several thousands of containers in operation, this process quickly becomes time-consuming and may reduce the throughput of the system considerably.

WO2017121515 describes an automated storage and retrieval system provided with an endless conveyor belt installed in two columns and connecting the upper part to the lower part of the storage system. The endless conveyor belt comprises a plurality of compartments fitted to hold containers in place and transport them from the upper part to the lower part. The control system issues instructions to control the speed of the conveyor belt and relative positions of the container handling vehicles operating on the rails of the system to provide optimal speed for loading/unloading of the containers.

A drawback associated with this system is that the conveyor belts occupy two port columns. In addition, the container handling vehicle will have to still wait for the arrival of the compartment, to drop-off the container. This would further decrease the efficiency of the system. A solution would be to install several conveyors that could operate simultaneously. However, this will add to the cost and complexity of the system and reduce the available space for storage of containers.

JPH02147005A describes an article storage facility for storing office supplies. The facility includes several cupboards with two conveyor systems arranged on top and below the cupboard. Storage containers with articles in them are transported from the bottom conveyor to the top conveyor by vertical lifts installed at both ends. Thus, forming a closed loop parallel to the floor. The vertical lift is provided with container holding members that hold and move the containers vertically.

The above-mentioned system is suitable for simpler applications where small articles can be transported along the vertical lift but is not suitable for installation in an automated storage system. Furthermore, the waiting times for container handling vehicles are not reduced.

As a result, there is a need for an efficient mechanism for transporting storage containers through the port columns, such that the mechanism reduces waiting times for the container handling vehicles, allowing the vehicles to perform other operations.

An objective of the present application is to provide a cost effective solution to transport storage containers through port columns, which improves overall efficiency of the storage system. SUMMARY OF THE INVENTION

The present invention is set forth and characterized in the independent claims, while the dependent claims describe other characteristics of the invention.

In in first aspect, the invention concerns a container transfer station for transferring storage containers between a storage volume within an automated storage and retrieval system (hereinafter referred to as ‘a storage system’) and a location external to the storage volume of the storage system.

The storage system may comprise a framework structure which includes a rail system comprising a first set of parallel rails arranged to guide movement of a container handling vehicle in a first direction X across the top of the framework structure and a second set of parallel rails arranged perpendicular to the first set of rails to guide movement of the container handling vehicle in a second direction Y which is perpendicular to the first direction X. The first and second sets of parallel rails divide the rail system into a plurality of grid cells. The framework structure comprising upright members defining storage columns for storing storage containers within the framework structure. The storage system may further comprise at least one container handling vehicle configured to operate on the rail system.

The container transfer station may comprise a vertical framework and a plurality of latches that may be configured to be movable vertically within the vertical framework.

The plurality of latches are further configured to hold a stack of containers at an elevated position in the vertical framework.

The elevated position may hereinafter be defined as a position in height which is at least equal to or more than the height of one storage container of the stack, measured from the lower end of the vertical framework. Such an elevated position ensures that a storage container may be removed from the vertical framework without interference with the stack of containers.

The container transfer station comprises a container support arranged at least in one vertical position below a lower end of the vertical framework. The container support is configured for supporting a lowermost container of the stack of containers, i.e. after releasing the lowermost container from underneath the stack.

The stack in the context of the container transfer station is hereinafter defined as storage containers that are vertically aligned and arranged on top of the other within the vertical framework. Hence, the stack in the container transfer station is different from the stack of containers stored within the storage volume of the storage system. The plurality of latches are further configured to release the lowermost container of the stack onto the container support and to maintain the remaining containers of the stack in the elevated position above the lowermost container in the vertical framework.

In an exemplary configuration, the plurality of latches may comprise at least two pairs of latches distributed on inner opposite side walls of the vertical framework. In this configuration each of the at least two pairs of latches is vertically aligned with each other, wherein each of the pair of latches is configured to engage with a particular container of the stack.

More preferably, the plurality of latches may comprise three pairs of latches distributed on the inner opposite side walls of the vertical framework, wherein each of the pairs of latches is configured to engage with a particular container of the stack, i.e. a container of the stack that is aligned in position with the pairs of latches.

Alternatively, or in addition, the plurality of latches may support a respective container of the stack from below.

In another exemplary configuration, the plurality of latches on either side of the framework may be controlled by a pair of releasable latching mechanism configured to control the latching and releasing of the containers of the stack.

In another exemplary configuration, each pair of latches may be configured to latch into slots provided on opposite external sides of the containers. In a specific example of this configuration, the slots may be provided on opposite side walls of the containers. Alternatively, or in addition, the pair of latches may latch into slots provided at the bottom of the container or pair of latches configured to support the container from underneath.

Each latch may be hooks, arms, bolt, clasp and the like, i.e. any element that is able to hold or support containers of the stack in place.

In another exemplary configuration, the at least two pair of latches may be configured to move vertically at equal speed so as to remain at level with each other in a carousel movement along the vertical framework. The carousel movement may be defined as movement of the pair of latches downwards on the inner side of the vertical framework and upwards on the outer side of the vertical framework.

Alternatively, or in addition the at least two pairs of latches may be configured to move upwards on the inner side of the vertical framework and downwards on the outer side of the vertical framework to perform the carousel movements.

In another exemplary configuration, the plurality of latches may comprise one or more motors allowing control of vertical movements of the plurality of latches, thereby allowing accurate positioning of the plurality of latches in relation to the stack of containers. The positioning may for example be achieved by positioning the arms, hooks, bolts or clasps in a holding position relative to their respective slots and/or in an abutment position on each side of the container of the stack. For example, the one or more motors may comprise a separate motor for each latch or each pair of latches, thereby allowing control of position and speed of each pair of latches. An equal speed during any vertical movements within the vertical framework is hence possible.

In another exemplary configuration, the plurality of latches may be configured such that the lowermost pair of latches may move vertically to increase the spacing to the pair of latches immediately above.

At least one of the pairs of latches may be driven by a rack and pinion arrangement with gears that allows control of the vertical latch movements, for example the vertical movements of the lowermost pair of latches.

In another exemplary configuration, each of the plurality of latches may be configured to move horizontally relative to the vertical framework, for example by operating a motor configured to allow retraction of the plurality of latches in direction from a vertical centre axis of the vertical framework. In other possible exemplary configurations, the plurality of latches may pivot downwards or upwards with a horizontal rotational axis or be folded into the vertical framework by the horizontal movement mechanism.

The motor(s) responsible for the controlled horizontal latch movements may be the same motor(s) which control(s) the vertical latch movements (see above).

In another exemplary configuration, the container support may be a conveyor system extending at least from the vertical framework to the location external of the storage volume and configured to transfer the containers to/from the location external to the framework. The conveyor system may further comprise a conveyor belt capable of supporting the containers released from the stack.

In another exemplary configuration, the external location (i.e. external to the storage volume) may be an area for processing the containers removed from the container transfer station such as a workstation / an access station as described in patent publication WO2012026824, WO2017211596, WO2022136423 herein incorporated by reference.

In an exemplary configuration, the container support may comprise a movement section configured to move vertically within the vertical framework until the lowermost container of the stack is supported onto the movement section. In this configuration, the container support may further comprise a motor allowing control of the vertical movements. The movement section may for example be a motorized endless belt conveyor. The part of the movement section supporting the container may be a removable plate or similar. In another exemplary configuration, the container support may be a vertical lift comprising a vertically extendable stand having a lower end and an upper end and a base fixed to the upper end. The stand and the base may be configured such that the stand may move the base between an upper position for supporting the lowermost container at the elevated position and a lower position in which the lowermost container may be transported to the external location.

The lower position may be the position in which an upper edge of the container is below the lower end of the vertical framework.

In another exemplary configuration, the container transfer station may comprise an opening in a lower part of the vertical framework through which the lowermost container may be transported to the external location. A lower boundary of the opening should thus be in vertical alignment with the said lower position of the container support.

In another exemplary configuration, the lowermost container may be transported to the external location by a human and/or a robotic operator. The robotic operator may for example be a robotic picking arm placed next to the container support, thereby allowing the lowermost container to be lifted off.

In a second aspect, the invention concerns an automated storage and retrieval system comprising a container transfer station as described above in the first aspect.

The automated storage and retrieval system (abbreviated storage system) comprises a framework structure for storing a plurality of storage containers stored in stacks in a storage volume. The framework structure comprises a rail system arranged above the stacks of the system, wherein the rail system comprises perpendicular rails, the intersections of which form a horizontal grid structure having grid cells defining grid openings. The framework structure further comprises a plurality of vertical upright members defining a plurality of storage columns for storing the stacks and a port column for transferring a storage container between the rail system and the external location (i.e. away from the framework structure). The port column may be arranged at least partly, preferably fully, within the container transfer station.

Finally, the storage system of the second aspect comprises a plurality of container handling vehicles configured to travel along the rail system and to transfer storage containers between the stacks and the port column.

In an exemplary configuration of the second aspect, the storage system may further comprise a controller set up to control operations of the plurality of latches and the container support.

In another exemplary configuration of the second aspect, the same controller as mentioned in connection with the first aspect controlling inter alia the plurality of latches may also be configured to control operation of the container handling vehicles operating on the rail system.

In another exemplary configuration of the second aspect, the vertical framework may be arranged at least partly, for example fully, along an outer side of the port column while also allowing horizontal retraction of the plurality of latches into the vertical framework as mentioned in connection with the first aspect. For example, the vertical framework may be positioned in relation to the port column such that the spacing in between the vertical framework and the port column accommodates the plurality of latches when they are retracted.

In another exemplary configuration of the second aspect, the vertical framework may be arranged to receive a container transferred by the container handling vehicle onto the stack of containers (for a definition of stacks in the container handling station, see definition for the first aspect). More preferably, different container handling vehicles may stack the containers into the vertical framework.

In another exemplary configuration of the second aspect, the plurality of latches comprises at least two pairs of latches, more preferably, at least three pairs of latches, distributed on an inner opposite side walls of the vertical framework. In this configuration, each of the at least two pairs of latches is vertically aligned with each other and configured to engage with a particular container of the stack by abutments and/or engaging into the slots provided on the container. The vertical framework and the port column may be mutually aligned such that the each of the at least two pairs of latches may move in a vertical direction and/or a horizontal direction without interference with the port column.

In a third aspect, the invention concerns a method for transferring storage containers between a storage volume within the storage system in accordance with the second aspect, and the external location, i.e. away from the storage volume, employing the container transfer station in accordance with the first aspect.

The method comprises the following steps:

- stacking a plurality of storage containers into the port column, and thus into the vertical framework, using the container handling vehicle(s);

- engaging/activating the plurality of latches to latch at least the lowermost container of the stack of containers (for definition of a stack within the vertical framework, see description for the first aspect);

- supporting the lowermost container of the stack onto the container support;

- releasing the lowermost storage container by operating/activating the plurality of latches; and

- holding the at least one storage container arranged above said lowermost storage container at a height equal to or higher than the elevated position by said plurality of latches. For a definition of ‘elevated position’, see description for the first aspect.

In an exemplary process of the third aspect, the plurality of latches may be engaged to latch the lowermost container by horizontal movement of the latches. Such horizontal movements in relation to the vertical framework are achieved by use of one or more horizontal movement mechanisms such as motor(s) described in the first aspect. The horizontal movements allows engagements / abutments of the latches onto the outer side walls of the containers and/or into slots of the containers, as well as retraction of the latches away from the containers. The horizontal movements may be of all types causing the engaging / abutting end to move to/from the outer side walls of the containers, such as by sliding, by pivoting and/or folding, all in relation to the vertical framework.

In another exemplary process of the third aspect, the plurality of latches may comprise at least two pairs of latches distributed on an inner opposite side walls of the vertical framework, preferably at least three pairs. In this exemplary process, each of the pairs of latches is vertically aligned. Furthermore, each of the pairs may be configured to engage with a slot provided on the side or alternatively beneath the container of the stack by the horizontal movements as described above

The method of the third aspect may further comprise the steps of

- operating/activating the at least two or three pairs of latches at an equal speed in a carousel movement to position the latches in relation to opposite outer side walls of the respective container, for example in respective slots; and

- operating the at least two or three pairs of latches horizontally to latch into the outer side walls / slots.

In another exemplary process of the third aspect, the carousel movement(s) of the pairs of latches may be driven by one or more motors allowing control of the latch movements.

In another exemplary process of the third aspect, the horizontal movement(s) of the pairs of latches may be controlled by one or more separate motors or the same motor(s) driving any carousel movement(s).

In another exemplary process of the third aspect, the horizontal movement(s) of the latches may be sliding movements from/to the vertical framework into/from engagements with the outer side walls of the container (for example into respective slots) or pivoting movements into/from said engagements. Folding movements similar to the extension / retraction of an accordion are also possible.

In another exemplary process of the third aspect, the container support extends at least from a lower section of the vertical framework to the external location (i.e. away from the storage volume / framework structure) and comprises a movement section arranged to move until abutment with the lowermost container of the stack is achieved. The method of the third aspect may further comprise the steps of:

- activating any carousel movement of the pairs of latches to move at least one of the pairs of latches at equal speed until the lowermost container is resting on the movement section;

- releasing the lowermost container onto the movement section of the container support by releasing the respective pair of latches;

- activating the movement section such that the lowermost container is transferred out to the external location; and

- activating the carousal movement of the pair of latches to latch into an upper unlatched container of the stack of containers.

In another exemplary process of the third aspect, the container support may comprise a conveyor system, in which the movement section forms a part of the conveyor system that is configured to move vertically within the framework. For example, the movement section may comprise a controllable endless belt vertically aligned with other modules having endless belts on one or both sides of the conveyor.

In another exemplary process of the third aspect, the movement section may be configured to move vertically within the vertical framework. The container support may thus comprise a motor allowing control of such vertical movements.

The method of the third aspect may further comprise the steps of

- moving the movement section vertically upwards to support the lowermost container onto the movement section;

- after releasing the lowermost storage container, for example by horizontally retracting the respective pair of latches using a rack and pinion system, moving the movement section vertically downwards in the vertical framework such that an upper edge of the storage container is below the vertical framework or below an upper edge of an opening (see description for the first aspect); and

- transporting the lowermost container by the container support to the external location (away from the storage volume).

In another exemplary process of the third aspect, the container support may be a vertical lift positioned in at least one position within the vertical framework. Such a vertical lift may comprise a vertically extendable stand having a lower end and an upper end and a base fixed to the upper end. The stand and the base may further be configured such that the stand is able to move the base between an upper position supporting the lowermost container at the elevated position and a lower position in which the lowermost container may be transported to the external location.

The method of the third aspect may further comprise the steps of

- moving the base to the upper position, i.e. where the lowermost container is supported onto the base;

- releasing the lowermost storage container by operating the respective pair of latches;

- moving the base to the lower position; and - transporting the lowermost container to the external location.

In another exemplary process of the third aspect, the vertical lift as described above may be part of the conveyor system, e.g. where the base comprises a controllable endless belt which may be vertically aligned with a remaining portion of the conveyor system. The stand of the vertical lift may be responsible for lifting or lowering the section of the conveyor system.

In an exemplary process of the third aspect, the plurality of latches may comprise a lowermost pair of latches, an uppermost pair of latches and one or more intermediate pairs of latches.

Furthermore, the carousel movement may comprise the steps of:

- releasing the lowermost pair of latches to release the lowermost container onto the container support;

- activating the carousel movement of the released lowermost pair of latches such that each latch on both sides of the vertical framework performs the following: proceed in a downward vertical movement along the inner side walls of the vertical framework, perform a 180° turn, or near a 180° turn, at the lower end of the vertical framework, proceed in an upward vertical movement along the outer side walls of the vertical framework, perform a 180° turn, or near a 180° turn, at a position of the vertical framework at or higher than an upper unlatched container in the stack; and if necessary, proceed in a downward vertical movement along the inner side walls of the vertical framework until vertical alignment with the upper unlatched container of the stack is achieved; and

- latching the lowermost pair of latches to the upper unlatched container in the stack.

In an exemplary process of the third aspect, a plurality of container handling vehicles may be assigned to load the stack of containers into the vertical framework 502. Each container handling vehicle may take turns to move towards the port column to drop off the storage container into the vertical framework to form a stack.

In another example of the above method, the method steps may be performed in a reverse order, by configuring the pair of latches to move in an upwards movement inside the vertical framework and downward movement outside. Thus, allowing transfer of storage containers through the vertical framework into the storage system.

In a fourth aspect, the invention concern a computer program product comprising instructions which, when the program is executed by a controller, cause the container transfer station of the first aspect to carry out the method of the third aspect..

BRIEF DESCRIPTION OF THE DRAWINGS Following drawings are appended to facilitate the understanding of the invention. The drawings show embodiments of the invention, which will now be described by way of example only, where:

Figure, l is a perspective side view of a framework structure of a prior art automated storage and retrieval system.

Figure. 2 is a perspective side view of a prior art container handling vehicle having an internally arranged cavity for carrying storage containers therein.

Figure. 3 is a perspective side view of a prior art container handling vehicle having a cantilever for carrying storage containers underneath.

Figure. 4 is a perspective side view, seen from below, of a prior art container handling vehicle having an internally arranged cavity for carrying storage containers therein.

Figure. 5a is a perspective side view, seen from one side, of a storage container according to the invention, employed in the automated storage and retrieval system.

Figure. 5b is a perspective view, seen from the top, of the storage container of figure 5a.

Figure. 6 is a perspective side view of a container transfer station according to the invention with a container support according to a first embodiment.

Figure. 7 is a perspective side view of a container transfer station of figure 6 showing a lowermost container transferred to the container support according to the first embodiment.

Figure. 8 is a perspective side view of a container transfer station showing the lowermost container released from the pair of latches.

Figure. 9 is a perspective side view of a container transfer station showing the carousel movement of the pair of latches and the lowermost container being transferred outside the vertical framework.

Figure. 10 and figure 11 shows a perspective side view of the carousel movement of the pair of latches and vertical movement of the stacks of containers towards the container support. Figure. 12 to figure 14 shows the sequence of steps of the container handling vehicle stacking a storage container into the vertical framework of the container transfer station.

Figure. 15 to figure 18 shows the sequence of operation of a second embodiment of the container support to transfer the stack of containers to the location outside the vertical framework.

DETAILED DESCRIPTION OF THE INVENTION

In the following, embodiments of the invention will be discussed in more detail with reference to the appended drawings. It should be understood, however, that the drawings are not intended to limit the invention to the subject-matter depicted in the drawings.

The framework structure 100 of the automated storage and retrieval system 1 is constructed in a similar manner to the prior art framework structure 100 described above in connection with Figs. 1-3. That is, the framework structure 100 comprises a number of upright members 102, and comprises a first, upper rail system 108 extending in the X direction and Y direction.

The framework structure 100 further comprises storage compartments in the form of storage columns 105 provided between the members 102 wherein storage containers 106 are stackable in stacks 107 within the storage columns 105.

The framework structure 100 can be of any size. In particular it is understood that the framework structure can be considerably wider and/or longer and/or deeper than disclosed in Figure. 1. For example, the framework structure 100 may have a horizontal extent of more than 700x700 columns and a storage depth of more than twelve containers.

The embodiments of the automated storage and retrieval system according to the invention will now be discussed in more detail with reference to Figs 5 to 18.

Throughout the description ‘storage container’ and ‘container’ may be used interchangeably.

Figure. 5a is a perspective side view and 5b is a top view of a storage container employed in the automated storage and retrieval system 1. The storage container 106 comprises a base 10, four side walls 14 enclosing the base 10 and defining a storage volume within the container 106. The storage container 106 is provided with slots 12 on each opposite side wall of the container 106. The slots 12 are shaped to allow the containers to be held or supported by a pair of latches. The latches latch into the slots 12 of the container 106 on either side. In an example embodiment of figure 5, the slots 12 are shown to be rectangular in shape, however the slots 12 may be square shaped or circular in shape. There may be more than one slot 12 provided on one side wall 14 on the storage container 106. In such a configuration, the corresponding latches are modified to fit into the plurality of slots 12.

The slots 12 may also be provided on both the side walls near the base of the container 106.

A container transfer station according to one embodiment will now be described with reference to Figs. 6-14. The container support in these figures is a conveyor system 508. With particular reference to Fig. 6, the container transfer station 500 of the first embodiment comprises a vertical framework 502 that is arranged at least partly or fully outside of the port column 105. The port column 105 may be integrated with the vertical framework 502 to form a single unit. Alternatively, the port column 105 may be temporarily enclosed by the vertical framework 502.

The port column 105 and the vertical framework 502 are arranged such that the space between them is capable of accommodating horizontal movement of the plurality of latches 504a-c to 504a’-c’ such as for example: retraction of the plurality of latches into the vertical framework 502, folding movement of the latches 504a-c to 504a’ -c’ or similar.

As depicted in the figure 6, the container transfer station 500 is stacked with plurality of storage containers 106a-d one on top of another and are held by means of a pair of releasable latch mechanism 504, 504’ provided on either side of the vertical framework 502. Each releasable latch mechanism 504, 504’ comprises a plurality of latches 504a-c to 504a’ -c’. The plurality of latches 504a-c to 504a’ -c’ latch into slots 12 provided on the side walls of the containers 106a-d. Alternatively, the pair of latches 504a-c to 504a’ -c’ hold the respective containers of the stack by clamping or squeezing onto the container(s) from the opposite sides.

The plurality of latches 504a-c to 504a’ -c’ may be hooks, arms, bolts, clasps, clamps or elements that have a similar configuration and allow supporting the containers 106a-d of the stack 106’. The elements must be capable of moving horizontally to latch and release the containers 106a-d. The plurality of latches 504a-c to 504a’ -c’ are arranged on the inner side wall of the vertical framework 502. The plurality of latches 504a-c to 504a’ -c’ are of the same shape and size and together form a pair of latches.

Furthermore, the each of the latches 504a-c are arranged on one side wall of the vertical framework 502 and mounted on a first belt embedded within the framework 502. While each of the latches 504a’ -c’ are mounted on the opposite side wall of vertical framework 502 and on a second belt that is embedded within the vertical framework 502.

The plurality of latches 504a-c to 504a’ -c’ further comprise at least three pairs of latches: a lowermost pair of latches 504a-a’, an intermediate pair of latches 504b-b’ and an uppermost pair of latches 504c-c’. However, any number of pairs of latches may be configured within the vertical framework 502 as per the requirement.

Each pair of latches 504a-a’ to 504c-c’ are aligned vertically to be level with one another. The lowermost pair of latches 504a-a’ are at an elevated position from the lower end 502’ of the vertical framework 502. The elevation is at least more than the height of one storage container 106 held by the stack 106’ of containers and measured from a lower end of the vertical framework 502. The elevation ensures that a storage container may be removed from the vertical framework 502 without interference with the stack 106’ of containers.

Further, each pair of latches 504a-a’ to 504c-c’ are arranged at equal distance from one another vertically within the framework 502.

The plurality of latches 504a-c to 504a’ -c’ are configured to move in a carousel movement within the vertical framework 502. Additionally, each of the pairs of plurality of latches 504a-c to 504a’ -c’ are also configured to move horizontally into and out of the vertical framework 502 by means of a horizontal movement mechanism.

The plurality of latches 504a-c to 504a’ -c’ are controlled by the releasable latch mechanism 504, 504’ by means of one or more motors. There may be a first motor configured to control the plurality of latches 504a-c on one belt and a second motor controlling the plurality of latches 504a’ -c’ on the second belt. Each of the pairs of latches 504a-a’, 504b-b’, 504c-c’ may be controlled by a separate motor each to achieve control of individual pairs of latches respectively. At the lower end 502’ of the vertical framework 502, a container support 508 is arranged. The container support is a conveyor system 508 comprising an endless conveyor belt and a movement section 508a. In an example of this embodiment, the movement section 508a is a motorized endless belt conveyor and is arranged to be aligned with the other sections of the conveyor system 508. The movement section 508a is also arranged such that it is positioned in alignment with the stack 106’ of containers 106a-d and can move vertically up and down within the vertical framework 502. The double ended arrows shows the movement section 508a may be moved vertically.

In the example of figures 6 to 14 the movement section 508a is described to function as an endless conveyor 508a that is configured to perform horizontal movements to transfer the lowermost container out of the vertical framework 502. This does not intend to limit the scope and the movement section 508a may also be configured to move vertically within the vertical framework 502 to support and retrieve the lowermost container 106a out of the framework 502.

In an embodiment, the movement section 508a may comprise a removable plate or similar component to support the lowermost container 106a.

An opening 516 is provided towards the lower end 502’ of the vertical framework 502 to remove and transport the containers 106 out of the vertical framework 502 to the external location 550. The opening 516 is arranged such that the lower boundary of the opening is in vertical alignment with the lower position of the container support 508/movement section 508a. This allows the transport of removed lowermost container 106a of the stack 106’ without hinderance.

An access station or a workstation may be mounted at the external location 550 and employed by a human or a robotic operator (such as for example a robotic picking arm) to retrieve the storage containers 106 removed from the container transfer station 500.

Figure. 7 is a perspective side view of a container transfer station of figure 6 showing a lowermost container transferred to the container support according to the first embodiment. The releasable latch mechanism 504, 504’ is activated by the first and second motors to drive the two belts as described above. The belts further move the plurality of latches 504a-c to 504a’ -c’ vertically downwards and upwards in a carousel movement. During the carousel movement, the latches 504a-c to 504a’ -c’ move downwards in a vertical movement on the inner side walls of the vertical framework 502, then turn in a near 180 degree motion at the lower end of the framework 502. The latches 504a-c to 504a’-c’then move vertically upwards along the outer side walls of the vertical framework 502 and turn 180 degree at a position equal to or higher than an unlatched container in the stack 106’. The carousel movement continues until the uppermost container is latched.

Furthermore, the carousel movement also causes the containers 106a-c supported by the plurality of latches 504a-c to 504a’ -c’ to move vertically downwards towards the conveyor system 508 until, the lowermost container 106a is resting on the conveyor 508a.

The conveyor section 508a may be provided with sensors to detect presence of the container 106a-d, when the container 106a-d arrives on the conveyor system 508. When the lowermost container 106a is resting on the conveyor system 508, the sensor detects the container 106a and sends instructions signals to a controller 109’. The controller 109’ then issues instructions signals back to the releasable latch mechanism 504, 504’ of the plurality of latches 504a-c to 504a’ -c’. The releasable latch mechanism 504, 504’ then operates the motor(s) controlling the lowermost pair of latches 504a-a’ to release the lowermost pair of latches 504a-a’. Thus, releasing the lowermost container 106a onto the conveyor 508a.

In an example, the sensors are one of proximity sensors, weight sensors or other sensors which are suitable for detection of a container 106a-d on the conveyor system 508.

It is observed that the spacing between the lowermost pair of latches 504a-a’ and the intermediate pair of latches 504b-b’ is greater as compared to the spacing between the intermediate pair of latches 504b-b’ and uppermost pair of latches 504c’c’. This is achieved by varying the speed of the motor controlling the operation of the lowermost pair of latches 504a-a’. In another example, the speed of the lowermost pair of latches 504a-a’ may be controlled by a rack and pinion arrangement with gears that vary the speed as desired on receiving the instruction signals from the controller 109’.

The possibility of varying the speed of movement of the lowermost pair of latches 504a-a’ allows sufficient time to handle the lowermost container 106a at the conveyor system 508.

Figure. 8 is a perspective side view of a container transfer station showing the lowermost container released from the lowermost pair of latches. As shown, the lowermost container 106a is released from the lowermost pair of latches 504a-a’ by the motor controlling the pair of latches 504a-a’ on receiving instruction signals from the controller 109’.

During the release, the lowermost pair of latches 504a-a’ move horizontally by a horizontal movement mechanism operated by the motor to be retracted into the vertical framework 502 in the direction from the vertical center axis of the framework 502. The horizontal movements allow engagements / abutments of the latches 504a- a’ onto the outer side walls of the container 106a and/or into slots 12 of the container 106a, as well as retraction of the latches 504a-a’ away from the container.

The horizontal movement may be a sliding mechanism that slides the latches (the latches for example may be an arm or a bolt) to release from the slot 12 of the container 106a-d into the framework 502. The horizontal mechanism may alternatively be a pivotable mechanism that causes the pair of latches 504a-a’ to pivot downwards or upwards with a horizontal rotational axis or a foldable mechanism that causes the pair of latches 504a-a’ to fold into the vertical framework 502. Further, the released lowermost container 106a may be removed from the opening at the lower end of the framework 502 without hinderance.

Figure. 9 is a perspective side view of a container transfer station showing the carousel movement of the pair of latches and the lowermost container being transferred outside the vertical framework. The released lowermost container 106a is transferred by the conveyor 508a of the conveyor system 508 by activating the movement of the conveyor system 508. The conveyor 508 conveys the lowermost container 106a through the opening 516 in the lower side 502’ of the vertical framework 502 to the external location 550. The external location 550 as described above, may include a workstation or an access station. At the external location 550, the container 106a is handled by human or a robotic operator.

The lowermost pair of latches 504a-a’ are seen moving in a carousel movement vertically upwards, as described above. This movement is driven by the motor controlling the lowermost pair of latches 504a-a’.

The remaining pairs of latches 504b-b’ and 504c-c’ are also seen to move vertically downwards. The pairs of latches 504b-b’ and 504c-c’ are controlled by the operation of separate motors controlling them individually. It is further noted that the remaining containers 106b-d of the stack 106’ are moving vertically downwards by the movement of the pairs of latches 504b-b’ and 504c-c’. The lowermost pair of latches 504a-a’ move upwards to engage with a storage container 106d on top of the stack 106’ that is unlatched.

Figure. 10 and figure 11 show a perspective side view of the carousel movement of the pair of latches and vertical movement of the stacks of containers towards the container support. In figure 10, the lowermost pair of latches 504a-a’ have moved up by the carousel movement of the pair of latches 504a-a’- 504c-c’. The lowermost pair of latches 504a-a’ will further latch into a new container of the stack 106’ that is available for latching, such as container 106d that is the next unlatched container of the stack 106’.

The carousel movement is also seen to move the container 106b to a lowermost container position. The container 106b is now resting on the conveyor system 508.

In figure 11, the lowermost container 106b is released by horizontal movement of the pair of latches 504b-b’. The horizontal movement as described above, is driven by the motor driving the pair of latches 504b-b’ on receiving instruction signals from the controller 109’. The released pair of latches 504b-b’ move in a carousel movement upwards.

Meanwhile, the pair of latches 504a-a’ can be seen latching into the slots 12 of the container 106d that is available at the top of the stack 106’.

The carousel movement of the latches also drives the remaining containers 106c, 106d vertically downwards. The container 106c is now in intermediate position in the stack 106’.

Figure. 12 to figure 14 shows the sequence of steps of the container handling vehicle stacking a storage container into the vertical framework of the container transfer station. In figure 12 to 14, the container handling vehicle 300 is seen lowering its lifting device into the vertical framework 502 to place a storage container 106e into the vertical framework 502. The storage container 106e is finally dropped off onto the top of the stack 106’ as seen in figure 14.

Meanwhile, the container 106b which was removed from the stack 106’ as seen in figure 12 is transferred outside of the vertical framework 502 on the conveyor 508 to the external location 550 or the access station.

In figure 12, the carousel movement of the pair of latches 504a-a’ to 504c-c’ is activated by motors controlling the movement of each of the pair of latches 504a-a’ to 504c-c’. The released pair of latches 504b-b’ are moving outwards the framework 502 vertically upwards. At the same time, the pair of latches 504a-a’ are observed to be latching into the slots 12 on the next unlatched storage container 106d of the stack 106’.

In figure 13, the pair of latches 504c-c’ have moved down by the motor controlling the pair of latches 504c-c’. While, the pair of latches 504b-b’ are upwards ready to latch into slots 12 of the next container 106e.

In figure 14, the pairs of latches 504c-c’ have moved downwards so that the container 106c is resting on the conveyor system 508. The controller 109’ on receiving instructions signals from the sensors on the conveyor system 508 sends instructions signals back to the motor controlling the pair of latches 508c-c’ to release the latches 508c-c’. The pair of latches 504c-c’ are released (as seen in figure).

The process then continues with the carousel movement of the pairs of latches 504a- a’ to 504c-c’ to vertically move the stack 106’ of containers downwards. Each time, the lowermost container 106x is removed from the vertical framework 502 and transported to the external location 550.

A container transfer station according to a second embodiment will now be described with reference to Figs. 15-18. The container support 508 in this embodiment is a vertical lift 508’ that is arranged at a lower end 502’ of the vertical framework 502 and is vertically aligned with the stack 106’within the framework 502.

The vertical lift 508’ comprises a movement section referred to as the base 508c a stand 508b, and an extendable conveyor section 508a. The stand 508b is a telescopic stand that moves the base 508c vertically between an upper position and a lower position. The stand 508b is configured to move the base 508c upwards such that the base 508c may support the lowermost container 106a of the stack 106’ at the elevated position. The elevation of the stack 106’ as described above is arranged such that the height is at least great than the height of a storage container 106 to allow free movement of the base 508c.

In figure 15, the base 508c of the vertical lift 508’ is at the lower position. The stack 106’ of containers 106a-c are latched by the plurality of latches 504a-c to 504a’-c’ at the elevated position from the lower end of the vertical framework 502.

In figure 16, the base 508c of the vertical lift 508’ is seen moving upwards by the telescopic stand 508b. In addition, the vertical lift 508’ may be provided with an electric motor or a hydraulic mechanism that may move the base 508c from the lower position to the upper position. The base 508c is supporting the lowermost container 106a of the stack 106’.

The base 508c may be configured with sensors that detect presence of a container on the base. When, the sensors detect the container 106a on the base 508c, they send instructions signals to the controller 109’. The controller 109’ sends instructions signals to the releasable latch mechanism 50a, 504’ to control the operation of the plurality of latches 504a-c to 504a’-c’, to release the container 106a.

In figure 17, the base 508c is seen at the lower position supporting the lowermost container 106c that is moved down. The releasable latch mechanism 504, 504’ controlling the pair of latches 504a-a’ operates the motor to release the pair of latches 504a-a’. The lowermost container 106a is released onto the base 508c. The base 508c further moves down to the lower position with the container 106a. The remaining pair of latches 504b-b’ and 504c-c’ are seen latched into the slots 12 of the container 106b, 106c respectively.

In figure 18, the movement section 508a of the vertical lift 508’is seen extended out of the vertical framework 502. The movement section 504a is a conveyor that extends out when activated and transfers the removed containers out of the vertical framework through the opening 516 at the lower end 502’ of the vertical framework 502. The conveyor 508a may be driven by a motor provided on the vertical lift 508’ and configured to control the activation of the conveyor 508a. The released container 106a is transferred to the external location 550 for further handling by a human or a robotic operator or a robotic picking arm.

In another embodiment, the container transfer station 500 may also be envisaged to transfer storage containers 106 into the storage volume of the storage system 1. In such a case, the container support 508 (the vertical lift or the movement section of the conveyor 508a) may be configured to transfer a storage container 106 vertically upwards to the elevated position, so that the container 106 is positioned just below the lowermost pair of latches 504a-a’. The controller 109’ may then send instruction signals to the motor operating the lowermost pair of latches 504a-a’. The lowermost pair of latches 504a-a’ move horizontally within the vertical framework 502 to allow the container support 508 to push the container 106, such that the container 106 is held by the pair of latches 504a-a’ by abutment from either sides into the slots 12 on the container.

In such a configuration, the plurality of latches 504a-a’ to 504-c-c’ may be configured to perform carousel movement by moving the pairs of latches 504a-a’ to 504c-c’ in an upward vertically movement on the inside of the vertical framework 502 and downwards movement outside the framework 502. The container 106 may thus be moved to the uppermost position in the stack 106’ by the carousel movements. The controller 109’ may then send instructions signals to a container handling vehicle 300 that is operating on top of the rails 108 of the framework 100 to pick up the container 106 from the vertical framework 502 and transfer the container 106 to an assigned location within the storage volume 104.

The container handling vehicle(s) 300 moves towards the port column 109 to retrieve the containers 106 from the stack 106’ and transfer the container 106 to an assigned location in the framework structure 100.

In an example scenario, there may be an error in handling a storage container 106 and the container may be wrongly placed on the container support 508. In another example, there may be an error in the system or with the container support 508 and thus there may be a requirement to transfer the container 106 back into the framework 100 of the storage system 1 and the aforementioned embodiment may be employed in transferring the container 106 back to the storage system 1.

In the preceding description, various aspects of the container transfer device, container handling vehicle and the automated storage and retrieval system according to the invention have been described with reference to the illustrative embodiment. For purposes of explanation, specific numbers, systems and configurations were set forth in order to provide a thorough understanding of the system and its workings. However, this description is not intended to be construed in a limiting sense. Various modifications and variations of the illustrative embodiment, as well as other embodiments of the system, which are apparent to persons skilled in the art to which the disclosed subject matter pertains, are deemed to lie within the scope of the present invention.

LIST OF REFERENCE NUMBERS

Prior art (figs 1-4):

Prior art automated storage and retrieval system 0 Framework structure 2 Upright members of framework structure 4 Storage grid 5 Storage column 6 Storage container 6’ Stack in the vertical framework 7 Stack of the storage system 1 8 Rail system 9 Control system 9’ Controller 0 Parallel rails in first direction (X) 1 Parallel rails in the second direction (Y) 2 Access opening 9 First port column 0 Second port column 0 Prior art container handling vehicle 1a Vehicle body of the container handling vehicle 200 1b Drive means / wheel arrangement / first set of wheels in first direction (X) 1c Drive means / wheel arrangement / second set of wheels in second direction (F) 0 Prior art cantilever container handling vehicle 1a Vehicle body of the container handling vehicle 300 1b Drive means / first set of wheels in first direction (X)1c Drive means / second set of wheels in second direction (F)4 Gripping device 0 Prior art container handling vehicle 1a Vehicle body of the container handling vehicle 400 1b Drive means / first set of wheels in first direction (X)1c Drive means / second set of wheels in second direction (F)4 Gripping device 4a Lifting band 4b Gripper 4c Guide pin 4d Lifting frame 0 Container transfer station 2 Vertical framework 504 Releasable latch mechanism

504a-c to 504a’-c’ Plurality of latches

504a-a’, b-b’, c-c’ Each pairs of latches

508 Conveyor system

508a Movement section of conveyor

508’ Vertical lift

508b Stand of the vertical lift

508c Base of the vertical lift

550 External location

10 Container base

12 Container slots

14 Container side walls

First direction r Second direction

Z Third direction

Claims

1. A container transfer station (500) for transferring storage containers (106) between a storage volume (104) within an automated storage and retrieval system (1) and a location (550) external to the storage volume (104), wherein the container transfer station (500) comprises

- a vertical framework (502);

- a plurality of latches (504a-c, 504a’ -c’) vertically movable within the vertical framework (502), wherein the plurality of latches (504a-c, 504a’-c’) are configured to hold a stack (106’) of containers (106a-d) at an elevated position in the vertical framework (502); and

- a container support (508) arranged at least in one vertical position below the vertical framework (502), wherein the container support (508) is configured for supporting a lowermost container (106a) when released from the stack (106’);

- wherein the plurality of latches (504a-c, 504a’-c’) are configured to release the lowermost container (106a) onto the container support (508) and to maintain the remaining containers (106b-d) in said elevated position.

2. The container transfer station (500) in accordance with claim 1, wherein the plurality of latches (504a-c, 504a’ -c’) comprises at least two pairs of latches (504a-a’, 504b-b’) distributed on inner opposite walls of the vertical framework (502); wherein each of the at least two pairs of latches (504a-a’, 504b-b’) is vertically aligned; and wherein each of the pair of latches (504a-a’, 504b-b’) is configured to engage with a container (106a-b) of the stack (106’).

3. The container transfer station (500) in accordance with claim 2, wherein each pair of latches (504a-a’, 50b’-b’) is configured to latch into slots (122) provided on opposite external sides of the containers (106).

4. The container transfer station (500) in accordance with claim 2 or 3, wherein the at least two pair of latches (504a-a’, 50b’-b’) are configured to move at equal speed in a carousel movement along the vertical framework (502).

5. The container transfer station (500) in accordance with any one of the preceding claims, wherein the plurality of latches (504a-c, 504a’ -c’) comprises a motor allowing control of vertical movements of the plurality of latches (504a-c, 504a’ -c’).

6. The container transfer station (500) in accordance with any one of the preceding claims, wherein each of the plurality of latches (504a-c, 504a’ -c’) is configured to move horizontally relative to the vertical framework (502).

7. The container transfer station (500) in accordance with any one of the preceding claims, wherein the container support is a conveyor system (508) extending at least from the vertical framework (502) to the location (550) external of the storage volume (104).

8. The container transfer station (500) in accordance with any one of the preceding claims, wherein the container support (508) comprises:

- a movement section (508a) configured to move vertically within the vertical framework (502) until the lowermost container (106a) of the stack (106’) is supported onto the movement section (508a); and wherein the container support (508) comprises a motor allowing control of said vertical movements.

9. The container transfer station (500) in accordance with claim 7, wherein the container support is a vertical lift (508’) comprising a vertically extendable stand (508b) having a lower end and an upper end and a base (508c) fixed to the upper end; wherein the stand (508b) and the base (508c) are configured such that the stand (508b) may move the base (508c) between an upper position for supporting the lowermost container (106a) at the elevated position and a lower position in which the lowermost container (106a) may be transported to the location (550) external to the storage volume (104).

10. The container transfer station (500) in accordance with any one of the preceding claims, wherein the container transfer station (500) comprises an opening (516) in the lower end (502’) of the vertical framework (502) through which the lowermost container (106a) may be transported to the location (550) external to the storage volume (104).

11. An automated storage and retrieval system (1) comprising

- a container transfer station (500) in accordance with any of claims 1 to 10;

- a framework structure (100) for storing a plurality of storage containers (106) stored in stacks (107) in a storage volume (104), the framework structure (100) comprising:

- a rail system (108) arranged above the stacks (107), the rail system (108) comprising perpendicular rails (110, 111), the intersections of which form a horizontal grid structure having grid cells (112) defining grid openings;

- a plurality of vertical upright members (102) defining a plurality of storage columns (105) for storing the stacks (107); and

- a port column (119,120) for transferring a storage container (106) between the rail system (108) and the location (550) external to the framework structure (100), wherein the port column (119, 120) is arranged at least partly within the container transfer station (500); and

- a plurality of container handling vehicles (200, 300, 400) configured to travel along the rail system (108) and to transfer storage containers (106) between the stacks (107) and the port column (119, 120).

12. The automated storage and retrieval system (1) in accordance with claim 11, wherein the system further comprises a controller (109’) configured to control operations of the plurality of latches (504a-c, 504a’-c’) and the container support (508).

13. The automated storage and retrieval system (1) in accordance with claims 11 to 12, wherein the vertical framework (502) is arranged at least partly along an outer side of the port column (119,120) and configured to allow retraction of the plurality of latches (504a-c, 504a’ -c’) into the vertical framework (502).

14. The automated storage and retrieval system (1) in accordance with claims 11 to 13, wherein the vertical framework (502) is arranged to receive a container (106e) transferred by the container handling vehicle (200, 300, 400) onto the stack (106’) of containers (106b-d).

15. The automated storage and retrieval system (1) in accordance with claim 11 to 14, wherein the plurality of latches (504a-c, 504a’ -c’) comprises at least two pairs of latches (504a-a’, 504b-b’) distributed on an inner opposite walls of the vertical framework (502), wherein each of the at least two pairs of latches (504a-a’, 504b-b’) is vertically aligned; wherein each of the pairs of latches (504a-a’, 504b-b’) is configured to engage with a container (106a-b) of the stack (106’), and wherein the vertical framework (502) and the port column (119, 120) are mutually aligned such that the each of the pair of latches (504a-a’, 504b-b’) may move in a vertical direction and a horizontal direction without interference with the port column (119, 120).

16. A method for transferring storage containers (106) between a storage volume (104) within an automated storage and retrieval system (1) in accordance with any one of claims 11 to 15 and the location (550) external to the storage volume (104); wherein the method comprises the following steps:

- stacking a plurality of storage containers (106a-d) into the vertical framework (502) using the container handling vehicle (200, 300, 400);

- engaging the plurality of latches (504a-c, 504a’-c’) to latch at least the lowermost container (106a) of the stack (106’);

- supporting the lowermost container (106a) of the stack (106’) onto the container support (508);

- releasing the lowermost storage container (106a) by operating the plurality of latches (504a-c, 504a’ -c’); and

- holding the at least one storage container (106b) arranged above said lowermost storage container (106a) at a height equal to or higher than the elevated position by said plurality of latches (504a-c, 504a’ -c’).

17. The method in accordance with claim 16, wherein the plurality of latches (504a-c, 504a’-c’) comprise at least two pairs of latches (504a-a’, 504b-b’) distributed on an inner opposite wall of the vertical framework (502), wherein each of the at least two pairs of latches (504a-a’, 504b-b’) is vertically aligned; and wherein each of the pair of latches (504a-a’, 504b-b’) is configured to engage with a container (106a-b) of the stack (106’); and wherein the method further comprises the steps of:

- operating the at least two pairs of latches (504a-a’, 504b-b’) at the equal speed in a carousel movement; and

- operating the at least two pairs of latches (504a-a’, 504b-b’) horizontally to latch into the slots (12).

18. The method in accordance with claim 16 to 17, wherein the container support (508) extends at least from the vertical framework (502) to the location (550) outside the storage volume (104), and comprises:

- a movement section (508a) arranged vertically aligned with the stack (106’) of containers (106a-d); and wherein the method comprises the steps of:

- activating the carousel movement of the pair of latches (504a-a’, 504b’-b’) such that the lowermost container (106a) is resting on the movement section (508a);

- releasing the lowermost container (106a) by releasing the pair of latches (504a-a’) onto the movement section (508a);

- activating the movement section (508a) to transfer the lowermost container (106a) to the location (550) external to the storage volume (104); and - activating the carousal movement of the pair of latches (504a-a’, 504b-b’) to latch into an upper unlatched container (106) of the stack (106’).

19. The method in accordance with claim 18, wherein the movement section (508a) is configured to move vertically within the vertical framework (502) and wherein the container support (508) comprises a motor allowing control of said vertical movements; and wherein the method comprises steps of:

- moving the movement section (508a) vertically upwards to support the lowermost container (104a) onto the section (508a);

- after releasing the lowermost storage container (106a), moving the movement section (508a) vertically downwards; and transporting the lowermost container (104a) to the location (550) external to the storage volume (104).

20. The method in accordance with any one of claims 16 to 17, wherein the container support is a vertical lift (508’) positioned in the vertical framework (502), the vertical lift (508) comprises:

- a vertically extendable stand (508b) having a lower end and an upper end; and

- a base (508c) fixed to the upper end, wherein the stand (508b) and the base (508c) are configured such that the stand (508b) may move the base (508c) between an upper position for supporting the lowermost container (106a) at the elevated position and a lower position in which the lowermost container (106a) may be transported to the location (550) external to the storage volume (104); and wherein the method comprises:

- moving the base (508c) to the upper position for supporting the lowermost container (106a) on the base (508c);

- after releasing the lowermost storage container (106a), moving the base (508c) to the lower position; and

- transporting the lowermost container (104a) to the location (550) external to the storage volume (104).

21. The method in accordance with any one of claims 16 to 20, wherein the plurality of latches (504a-c, 504a’-c’) comprises: a lowermost pair of latches (504a, 504a’), an uppermost pair of latches (504c, 504c’) and an intermediate pair of latches (504b, 504b’), and wherein the carousel movement comprises the steps of:

- releasing the lowermost pair of latches (504a, 504a’) to release the lowermost container (104a) onto the container support (508); - activating the carousel movement of the released two lowermost pair of latches (504a, 504a’) vertically upwards; and

- latching the lowermost pair of latches (504a, 504a’) to an upper unlatched container (104c) in the stack (106’).

22. A computer program product comprising instructions which, when the program is executed by a controller, cause the container transfer station (500) as claimed in any of claims 1 to 10 to carry out the method as claimed in in any of claims 16 to 21.