Patent Description:
Some commercial and industrial activities require systems that enable the storage and retrieval of a large number of different products. One known type of system for the storage and retrieval of items in multiple product lines involves arranging storage bins or containers in stacks on top of one another, the stacks being arranged in rows. The storage bins or containers are accessed from above, removing the need for aisles between the rows and allowing more containers to be stored in a given space.

Methods of handling containers stacked in rows have been well known for decades. In some such systems, for example as described in <CIT>, to Bertel comprise free-standing stacks of containers arranged in rows in order to reduce the storage volume associated with storing such containers but yet still providing access to a specific container if required. Access to a given container is made possible by providing relatively complicated hoisting mechanisms which can be used to stack and remove given containers from stacks. The cost of such systems are, however, impractical in many situations and they have mainly been commercialised for the storage and handling of large shipping containers. The concept of using freestanding stacks of containers and providing a mechanism to retrieve and store specific containers has been developed further, for example as described in <CIT> B (Cimcorp). <CIT> B discloses a mechanism for removing a plurality of stacked containers, using a robotic load handler in the form of a rectangular tube which is lowered around the stack of containers, and which is configured to be able to grip a container at any level in the stack. In this way, several containers can be lifted at once from a stack. The movable tube can be used to move several containers from the top of one stack to the top of another stack, or to move containers from a stack to an external location and vice versa. Such systems can be particularly useful where all of the containers in a single stack contain the same product (known as a singleproduct stack).

In the system described in <CIT> B, the height of the tube has to be at least as high as the height of the largest stack of containers, so that the highest stack of containers can be extracted in a single operation. Accordingly, when used in an enclosed space such as a warehouse, the maximum height of the stacks is restricted by the need to accommodate the tube of the load handler.

<CIT>) describes a system in which stacks of containers are arranged within a frame structure. A system of this type is illustrated schematically in <FIG> of the accompanying drawings. Robotic load handling devices can be controllably moved around the stack on a system of tracks on the upper most surface of the stack.

<CIT> discloses a storage system according to the preamble of claim <NUM>.

It is a disadvantage of the prior art systems described above that the temperature within densely packed stacks is difficult to accurately regulate. According to the invention there is provided a storage system as defined by claim <NUM>.

Preferably, the temperature of the storage system can be varied from -<NUM><NUM>C to +<NUM><NUM>C.

Preferably, the temperature of the storage system can be controlled within a range of ±<NUM><NUM>C.

Alternatively, the gas is a coolant gas.

In this way, the present invention overcomes the problems of the prior art and provides a storage system capable of accurately maintaining and varying the temperature within a stacked grid storage system.

The invention will now be described with reference to the accompanying diagrammatic drawings in which:.

As used herein the term plenum is a space or chamber for receiving heated or cooled air.

As shown in <FIG> and <FIG>, stackable containers, known as bins <NUM>, are stacked on top of one another to form stacks <NUM>. The stacks <NUM> are arranged in a grid frame structure <NUM> in a warehousing or manufacturing environment. <FIG> is a schematic perspective view of the frame structure <NUM>, and <FIG> is a top-down view showing a single stack <NUM> of bins <NUM> arranged within the frame structure <NUM>. Each bin <NUM> typically holds a plurality of product items (not shown), and the product items within a bin <NUM> may be identical, or may be of different product types depending on the application.

The frame structure <NUM> comprises a plurality of upright members <NUM> that support horizontal members <NUM>, <NUM>. A first set of parallel horizontal members <NUM> is arranged perpendicularly to a second set of parallel horizontal members <NUM> to form a plurality of horizontal grid structures supported by the upright members <NUM>. The members <NUM>, <NUM>, <NUM> are typically manufactured from metal. The bins <NUM> are stacked between the members <NUM>, <NUM>, <NUM> of the frame structure <NUM>, so that the frame structure <NUM> guards against horizontal movement of the stacks <NUM> of bins <NUM>, and guides vertical movement of the bins <NUM>.

The top level of the frame structure <NUM> includes rails <NUM> arranged in a grid pattern across the top of the stacks <NUM>. Referring additionally to <FIG> and <FIG>, the rails <NUM> support a plurality of robotic load handling devices <NUM>. A first set 22a of parallel rails <NUM> guide movement of the load handling devices <NUM> in a first direction (X) across the top of the frame structure <NUM>, and a second set 22b of parallel rails <NUM>, arranged perpendicular to the first set 22a, guide movement of the load handling devices <NUM> in a second direction (Y), perpendicular to the first direction. In this way, the rails <NUM> allow movement of the load handling devices <NUM> in two dimensions in the X-Y plane, so that a load handling device can be moved into position above any of the stacks <NUM>.

Each load handling device <NUM> comprises a vehicle <NUM> which is arranged to travel in the X and Y directions on the rails <NUM> of the frame structure <NUM>, above the stacks <NUM>. A first set of wheels <NUM>, consisting of a pair of wheels <NUM> on the front of the vehicle <NUM> and a pair of wheels <NUM> on the back of the vehicle <NUM>, are arranged to engage with two adjacent rails of the first set 22a of rails <NUM>. Similarly, a second set of wheels <NUM>, consisting of a pair of wheels <NUM> on each side of the vehicle <NUM>, are arranged to engage with two adjacent rails of the second set 22b of rails <NUM>. Each set of wheels <NUM>, <NUM> can be lifted and lowered, so that either the first set of wheels <NUM> or the second set of wheels <NUM> is engaged with the respective set of rails 22a, 22b at any one time.

When the first set of wheels <NUM> is engaged with the first set of rails 22a and the second set of wheels <NUM> are lifted clear from the rails <NUM>, the wheels <NUM> can be driven, by way of a <NUM> drive mechanism (not shown) housed in the vehicle <NUM>, to move the load handling device <NUM> in the X direction. To move the load handling device <NUM> in the Y direction, the first set of wheels <NUM> are lifted clear of the rails <NUM>, and the second set of wheels <NUM> are lowered into engagement with the second set of rails 22a. The drive mechanism can then be used to drive the second set of wheels <NUM> to achieve movement in the Y direction.

In this way, one or more robotic load handling devices <NUM> can move around the top surface of the stacks <NUM> on the frame structure <NUM> under the control of a central picking system (not shown). Each robotic load handling device <NUM> is provided with means for lifting out one or more bins or containers from the stack to access the required products. In this way, multiple products can be accessed from multiple locations in the grid and stacks at any one time.

It will be noted from the description above and with reference to the drawings, that the portion of the load handling device <NUM> carried by the wheels covers one grid spacing of the grid system above the stack.

<FIG> shows a typical storage system as described above, the system having a plurality of load handling devices <NUM> active on the stacks <NUM>.

With reference to <FIG> the storage system of the present invention comprises a series of storage bins or containers <NUM> stacked one on top of another to form a storage stack <NUM>.

As shown in <FIG> each storage container has one or more apertures <NUM> in one or more sides to allow air to circulate freely through the storage container. This container can vary in shape and size.

The apertures are shaped and sized such that they do not undermine the strength or structural integrity of the storage container. Preferably between <NUM> % and <NUM> % of the surface area of the side of the storage container should be open in the form of apertures to allow air flow through the container. Apertures may be provided in <NUM>,<NUM>,<NUM>,<NUM> or <NUM> sides of the container.

As shown in <FIG> a plurality of stacks are arranged in a grid frame structure <NUM> to form a high density grid storage system.

One or more chiller units <NUM> are located above the storage stacks and form a reservoir <NUM> of cooled air above the storage stacks. As shown by the arrows in <FIG> the cooled air moves between, around and through the storage stacks and enters a plenum <NUM>.

The plenum <NUM> comprises a channel of height <NUM> and width <NUM>. The width <NUM> of the plenum <NUM> can vary from <NUM> to <NUM>. The height of the plenum <NUM> can vary from the same height as the storage system to <NUM> below the top of the storage system.

The plenum is sealed on three sides. The plenum has an opening adjacent the storage stacks.

As shown in <FIG> the plenum <NUM> is located along one or more side of the grid of stacks.

One or more fans <NUM> are located either on the top of the plenum <NUM> as shown in <FIG> or on the vertical face of the plenum as shown in <FIG>.

The one or more fans <NUM> helps to circulate the cooled air from the reservoir <NUM> through around, and between the storage stacks to the plenum <NUM>
As the cooled air circulates through the storage system it adjusts the temperature of the storage stacks and their contents.

The chiller units <NUM> units can be located either directly above the plenums as shown in <FIG> or they can be set back as shown in <FIG>. The key requirement is that a reservoir of cooled air <NUM> is created above the storage system.

The number, size and location of chiller units will vary depending on the size of the storage system.

The width of the storage system <NUM> can vary from <NUM> to <NUM>, however, it will be appreciated that any width of storage system may be envisaged with suitable adjustments to the equipment required.

The length <NUM> of the storage system has no upper limit. Multiple plenums, fans, and chillers can be positioned periodically along the entire length of the storage system to achieve the desired level of temperature control.

The height <NUM> of the system can be up to <NUM> high.

The power and number of fans <NUM> depends on the size of the system with diameter of the fans varying from <NUM> to <NUM>.

In an alternative embodiment the chiller units may be supplemented by heater units. The reservoir <NUM> is then one of temperature controlled air.

In an alternative embodiment a gas other than air e.g. a coolant may be circulated in the storage system to better assist temperature regulation.

In an alternative embodiment the chillers <NUM> may be replaced with heaters which form a reservoir of heated air above the storage stacks.

The temperature of the storage system can be controlled within a range of ±<NUM><NUM>C.

The temperature within the storage system can be varied from -<NUM><NUM>C to +<NUM><NUM>C.

Referring to <FIG> which is a plan view of an alternative embodiment of a storage system not according to the claimed invention in which the stacks within the grid storage system are of different widths. The plenum follows the edge of the storage system grid even as the width of the grid changes.

The plenum does not need to provide a uniform, continuous straight channel to be effective.

<FIG> shows an alternative arrangement not according to the claimed invention in which one or more rows <NUM> are omitted within the grid of stacks. These empty rows <NUM> allow some of the cold reservoir air to fall through the storage system and thus promote additional air flow through the stacks of containers. The width of empty rows can vary from <NUM> wide to <NUM> wide. Optionally the empty rows can be partially filled with empty or filled storage containers.

<FIG> shows the system raised above the floor <NUM>. In this embodiment, which is not encompassed by the wording of the claims, air is circulated around, though between and under the stacks to regulate their temperature.

<FIG> shows a storage system not according to the claimed invention on a mezzanine floor raised above ground level <NUM>. Air travels from the reservoir though the stacks to vertical <NUM> and horizontal <NUM> ducting located in the mezzanine floor. The ducting channels air under the stacks and towards the plenum.

<FIG> shows the use of storage containers of a different design on the bottom level of each stack. The containers have additional and larger apertures <NUM> in them to allow greater air flow but still have sufficient strength to be able to support storage containers stacked on top of them.

With reference to <FIG> in an alternative embodiment not according to the claimed invention the storage containers on the bottom level of one or more stack comprise ducting <NUM> running through the container to further aid the circulation of temperature controlled gas from reservoir <NUM> or temperature controlled fluids from elsewhere.

With reference to <FIG> in an embodiment of the invention, tubes <NUM> are provided in the walls of the grid to further aid the circulation of temperature controlled gas from reservoir <NUM> or temperature controlled fluids from elsewhere to reduce the temperature variation throughout the storage stacks. The tubes <NUM> can be used to either draw or force fluids through the storage system.

Moreover, the temperature controlled air may be further directed and circulated through ducting or holes and cavities within the uprights and framework <NUM> structure of the storage system.

It will be appreciated that the foregoing embodiments are described in terms of a temperature control system for a storage system such as that used as part of an online retail operation. However, it will be appreciated that a similar form of temperature control system may be used in a similar structure of storage system used for other applications. For example, use of such storage systems has been envisaged for a mechanized greenhouse wherein the containers <NUM> contain plants or other living organisms growing under controlled conditioned. In such systems, control of temperature may be critical but additionally humidity, air flow and other environmental variables may require control. It will be appreciated that use of the temperature controlling system hereinbefore describe may advantageously assist in the control of humidity, air flow and the like.

Claim 1:
A storage system (<NUM>) comprising:
a plurality of upright members (<NUM>);
two substantially perpendicular sets of rails (22a, 22b) supported by the plurality of upright members (<NUM>) and forming a grid above a workspace, the workspace comprising a plurality of stacked containers (<NUM>), each stack of containers (<NUM>) in the workspace corresponding to an opening in the grid; and,
a plurality of robotic load handling devices (<NUM>) operating on the grid above the workspace, the load handling devices (<NUM>) comprising a body mounted on wheels (<NUM>, <NUM>), a first set of wheels (<NUM>) being arranged to engage with at least two rails of the first set of rails (22a), the second set of wheels (<NUM>) being arranged to engage with at least two rails of the second set of rails (22b), the first or second set of wheels (<NUM>, <NUM>) being independently moveable and driveable with respect to the other of the first or second set of wheels (<NUM>, <NUM>) such that when in motion only one set of wheels (<NUM>, <NUM>) is engaged with the grid at any one time thereby enabling movement of the load handling device (<NUM>) along the rails (<NUM>) to any point on the grid by driving only the set of wheels (<NUM>, <NUM>) engaged with the rails (22a, 22b), the load handling devices (<NUM>) being provided with means for lifting out one or more containers (<NUM>) from a stack through a corresponding opening in the grid,
characterised in that the storage system (<NUM>) further comprises:
at least one heater and/or at least one chiller (<NUM>) located above the workspace for generating a reservoir (<NUM>) of temperature controlled gas above the workspace;
a plenum (<NUM>) comprising an opening adjacent a side of the stacked containers (<NUM>) for receiving the temperature controlled gas;
at least one fan (<NUM>) being adapted to circulate temperature controlled gas through the stacked containers (<NUM>) to the plenum (<NUM>); and,
a plurality of ducts formed as tubes (<NUM>) provided in the upright members (<NUM>) and extending between them, the tubes (<NUM>) being configured to further aid the circulation of temperature controlled gas from the reservoir (<NUM>) to reduce temperature variation throughout the stacks of containers (<NUM>), wherein each storage container (<NUM>) comprises one or more apertures (<NUM>) in the sides to allow the temperature controlled gas to circulate freely through the storage container (<NUM>).