Track assembly for storage and retrieval system

Abstract

A track system for a storage and retrieval system is provided, the track system comprising one or more load handling devices operable on the track system. The track system comprises a plurality of tracks arranged in a grid pattern and a plurality of track supports arranged in the grid pattern, the plurality of track supports comprising a first set of track supports (460) extending in a first direction and a second set of track supports (460A) extending in a second direction substantially perpendicular to the first direction. Each of the plurality of track supports is formed from a sheet metal blank folded along a plurality of bend lines. The first set of track supports (460) intersect with the second set of track supports (460A) by the second set of track supports (460A) being received in one or more notches (478) in the first set of track supports (460) at one or more nodes in the track system.

Description

[Technical Field]

[0001] The present invention relates to the field of storage or fulfillment systems in which stacks of bins or containers are arranged within a grid framework structure, and more particularly to a track system configured to guide one or more load handling devices operable to move one or more containers stored in the storage or fulfillment system. [Background technology]

[0002] Storage systems comprising a three-dimensional storage grid structure within which storage containers / bins are stacked on top of one another are known. PCT Publication No. WO2015 / 185628A (Ocado) describes a known storage and fulfillment system in which stacks of bins or containers are arranged within a grid framework structure. The bins or containers are accessed by load handling devices operable on trucks located on top of the grid framework structure. A system of this type is illustrated diagrammatically in Figures 1 to 3 of the accompanying drawings.

[0003] As shown in Figures 1 and 2, stackable containers known as bins 10 are stacked on top of each other to form a stack 12. The stack 12 is arranged in a grid framework structure 14 in a warehouse or manufacturing environment. The grid framework structure is made up of a plurality of storage columns, or grid columns. Each grid in the grid framework structure has at least one grid column for storing a stack of containers. Figure 1 is a schematic perspective view of the grid framework structure 14, and Figure 2 is a top view showing the stack 12 of bins 10 arranged within the framework structure 14. Each bin 10 typically holds multiple product items (not shown), which may be of different product types or may be the same depending on the application.

[0004] The grid framework structure 14 includes a plurality of upright members 16 supporting horizontal members 18, 20. A first set of parallel horizontal grid members 18 are arranged perpendicular to a second set of parallel horizontal members 20 in a grid pattern, forming a plurality of horizontal grid structures supported by the upright members 16. The members 16, 18, 20 are typically fabricated from metal. The bins 10 are stacked between the members 16, 18, 20 of the grid framework structure 14 such that the grid framework structure 14 guards the stack 12 of bins 10 against horizontal movement and guides the vertical movement of the bins 10.

[0005] The top level of the grid framework structure 14 comprises a grid or grid structure including rails or tracks 22 arranged in a grid pattern across the top of the stacks 12 to define a track system. Still referring to FIG. 3 , the rails or tracks 22 guide a plurality of load handling devices 30. The track system comprises a first set 22a of parallel rails 22 that guide movement of the robotic load handling devices 30 in a first direction (e.g., the X direction) across the top of the grid framework structure 14, and a second set 22b of parallel rails 22 disposed perpendicular to the first set 22a that guide movement of the load handling devices 30 in a second direction (e.g., the Y direction) perpendicular to the first direction. In this manner, the rails 22 enable movement of the robotic load handling devices 30 laterally in two dimensions in the horizontal XY plane, such that the load handling devices 30 can be moved to a position above any of the stacks 12.

[0006] The upright columns of the grid framework structure are interconnected at their upper ends by rails or tracks that intersect within the grid. The intersections of the rails or tracks in the grid structure are commonly referred to as "nodes" of the grid structure. Typically, the first and second sets comprise individual elongated rail or track sections that are interconnected to each other in first and second directions at interconnections where the tracks or rail sections meet at the upper ends of the upright columns. The rails or tracks typically comprise elongated elements that are profiled to guide load handling devices on the grid structure, and are typically profiled to provide either a single track surface to allow a single load handling device to travel on the track, or dual tracks to allow two load handling devices to pass each other on the same track. When the elongated elements are profiled to provide a single track, the track has opposing lips along the length of the track (one lip on one side of the track and another lip on the other side of the track) to guide or restrain each wheel from lateral movement on the track. When the elongate element profile is double track, the track includes two pairs of lips along the length of the track to allow adjacent load handling device wheels to pass each other in both directions on the same track. To provide the two pairs of lips, the track typically includes a central ridge or lip and lips on either side of the central ridge. In all cases, when traversing over the grid structure, the wheels of the load handling device are constrained on either side or both sides of the load handling device wheels.

[0007] The tracks or rails may be separate components from the grid members (referred to as "track supports"), or alternatively, the tracks are integrated into, i.e., form part of, the grid members as a single body. For example, each of the first and second sets of horizontal grid members 18, 20 of the grid structure may function as a track support, and the first and second sets of tracks of the track system may be attached to the grid structure to guide load handling devices in two dimensions over the grid structure.

[0008] WO 2018 / 146304 (Autostore Technology AS) teaches a rail arrangement for wheeled vehicles in a storage system, the rail arrangement comprising a first set of parallel rails and a second set of parallel rails. The first and second sets of parallel rails form a grid where the second set is arranged perpendicular to the first set and intersects with the first set at their intersections, thus forming a grid of parallel rails. The intersections of the intersecting rails correspond to the interconnection of the upright columns. Each of the rails of both sets of rails comprises two parallel tracks adapted to guide the wheels of a vehicle or load handling device. The rail or track comprises a plurality of longitudinal segments or sections having two edge ridges extending along each longitudinal edge of the longitudinal segments and a central ridge extending parallel to the edge ridges. The area between the ridges forms a track for receiving and guiding the wheels of the vehicle. The width of the central ridge is adapted to ensure that two vehicles can pass each other when traveling on the track in different directions on the same segment. The edge ridges of each crossing rail are in contact with each other, forming corner ridges. The corner ridges are tightly connected and positioned to prevent the vehicle from getting stuck at the joint. The corner ridges are rounded on the inside to allow the vehicle to travel smoothly through the intersection.

[0009] A known load handling device 30 shown in Figures 4 and 5 comprising a car body 32 is described in PCT Patent Publication No. WO2015 / 019055 (Ocado), which is incorporated herein by reference, where each load handling device 30 covers only one grid space of the grid framework structure 14. Here, the load handling device 30 comprises a wheel assembly comprising a first set of wheels 34 consisting of a pair of wheels on the front of the car body 32 and a pair of wheels 34 on the rear of the car body 32 for engaging a first set of rails or tracks to guide movement of the device in a first direction, and a second set of wheels 36 consisting of a pair of wheels 36 on each side of the car body 32 for engaging a second set of rails or tracks to guide movement of the device in a second direction. Each of the sets of wheels is driven to enable movement of the vehicle in the x and y directions along the rails, respectively. One or both sets of wheels can be moved vertically to lift each set of wheels off its respective rail, thereby allowing the vehicle to move in a desired direction on the grid.

[0010] The load handling device 30 is equipped with a lifting device or crane mechanism for lifting the storage container from above. The crane mechanism includes a winch tether or cable 38 wound on a spool or reel (not shown) and a grabber device 39. The lifting device includes a set of lifting tethers 38 (one tether near each of the four corners of the grabber device) that extend vertically and are connected near or at the four corners of a lifting frame 39, also known as a grabber device, for releasable connection to the storage container 10. The grabber device 39 is configured to releasably grasp the top of the storage container 10 in order to lift the storage container 10 from a stack of containers in a storage system of the type shown in FIGS. 1 and 2.

[0011] The wheels 34, 36 are positioned around the periphery of a cavity or recess known as a container-receiving recess or container-receiving space 41 at the bottom. The recess is sized to accommodate the container 10 when it is lifted by the crane mechanism, as shown in FIGS. 5(a) and 5(b). When in the recess, the container is lifted off the rail below, allowing the vehicle to move laterally to a different location. Upon reaching a target location, such as another stack, an access point in a storage system, or a conveyor belt, the bin or container can be lowered from the container-receiving portion and released from the grabber device. The container-receiving space may comprise a cavity or recess located within the vehicle body, for example, as described in WO 2015 / 019055 (Ocado Innovation Limited). Alternatively, the body of the load handling device may comprise a cantilever, as taught in WO 2019 / 238702 (Autostore Technology AS), in which case the container-receiving space is located below the cantilever of the load handling device. In this case, the grabber device is lifted by the cantilever so that it can engage the container and lift it from the stack into the container receiving space below the cantilever.

[0012] To ensure the stability of the grid framework structure, prior art storage systems rely heavily on various supports and braces located within or at least partially along the periphery of the grid framework structure. However, using various supports and braces (anti-motion braces) to stabilize the grid framework structure from internal and external forces is disadvantageous for several reasons. The grid framework structure occupies space or area that could be utilized for storing containers, preventing optimal use of the space or area available for container storage. Because any secondary grid support structure often requires connection to surrounding structures, such as the interior walls of a building, the need for support structures can limit the options available for positioning the grid framework structure. Requiring support structures to stabilize the grid framework structure is generally cost-ineffective and occupies useful storage space.

[0013] To erect a grid framework structure in the art, multiple vertical uprights are individually placed on the ground in a grid-like pattern, one piece at a time. Assembling individual vertical uprights one piece at a time is sometimes referred to as "stick-built" construction. The "stick-built" approach to assembling a grid framework structure requires many time-consuming adjustments for reliable operation of a robotic load handling device on a truck. The height of the vertical uprights, and hence the level of the grid mounted thereon, is adjusted by one or more adjustable feet at the base or lower end of each vertical upright. Subgroups of vertical uprights are braced to one another to provide structural stability to the grid framework structure. The vertical uprights are interconnected at their upper ends by grid members such that the grid members adopt the same grid pattern as the vertical uprights; i.e., the vertical uprights support the grid members at the points or nodes where each of the grid members intersect in the grid pattern. For purposes of this description, the points or junctions where grid members intersect or interconnect constitute nodes of the grid structure and correspond to areas where the grid structure is supported by vertical uprights. The resulting grid framework structure may be thought of as a free standing rectilinear assemblage of upright columns supporting a grid formed from intersecting horizontal grid members, i.e., a four-walled framework.

[0014] The arrangement of vertical uprights provides multiple vertical storage columns for storing one or more containers in a stack. The vertical uprights serve to guide grabber devices of a lifting mechanism as they engage containers in the grid framework structure and lift them toward load handling devices operable on the grid. The size of the grid framework structure, and therefore its ability to store containers containing different items or stock keeping units (SKUs), is highly dependent on the number of vertical uprights across a given footprint of the grid framework structure. However, one of the largest bottlenecks in building a fulfillment or distribution center is the construction of the grid framework structure. The time and cost to assemble the grid framework structure accounts for a large portion of the time and cost to build a fulfillment or distribution center.

[0015] Furthermore, to construct a track system in the prior art, rails or tracks are extruded from metal, such as aluminum, and multiple rail or track sections are required to construct the track system. The more rail or track sections required to construct the track, the more complex the assembly of the track system becomes. Often, there is a two-to-one relationship between the number of rail or track sections or segments at each node or intersection of the track or rail sections in a grid framework structure, meaning that multiple rail or track sections are connected to each other at each node of the grid structure. For example, in WO 2018 / 146304 (Autostore Technology AS), when creating an intersection between a first set of rails or tracks and a second set of rails or tracks, all of the second set of rails or tracks include recesses into which the first set of rails or tracks can be placed. Furthermore, multiple track or rail sections of different sizes are connected to each other within the grid structure to provide multiple rectangular or square grid cells. For example, for each grid cell, there is a rail or track section extending in one direction for a certain length and another track or rail section extending in a second direction for a different length. The different lengths of rail or track sections meet at nodes in the grid structure where they intersect. The need to have rail or track sections of different lengths complicates the assembly of track or rail sections in a grid pattern.

[0016] Therefore, there is a need for a track or rail system that requires the use of fewer rail or track sections when assembling the track, allowing for easier assembly.

[0017] This application claims priority to GB Application No. 2216881.9, filed November 11, 2022, and GB Application No. 2216891.8, filed November 11, 2022, the contents of which are incorporated herein by reference. Summary of the Invention

[0018] Aspects of the invention are set out in the accompanying claims.

[0019] A track system for a storage and retrieval system is provided, comprising one or more load handling devices operable on the track system, the track system comprising a plurality of tracks on which the load handling devices may travel on a grid structure, the plurality of tracks being arranged in a grid pattern and defining the grid structure lying in a horizontal plane, each of the plurality of tracks being subdivided into a plurality of elongated track elements; wherein each of the plurality of elongated track elements is formed from a sheet metal blank having at least two bend lines to form a substantially U-shaped cross-section having upper and lower flanges and a vertical element extending between the upper and lower flanges, wherein one or more of the plurality of tracks is integral with the upper flange.

[0020] A track system for a storage and retrieval system comprising one or more load handling devices operable on the track system, the track system comprising a plurality of tracks arranged in a grid pattern comprising a plurality of grid cells within which the load handling devices can move on the grid structure, the plurality of tracks arranged in the grid pattern to define a grid structure lying in a horizontal plane, each of the plurality of tracks being subdivided into a plurality of elongated track elements; wherein the track system further comprises a track support structure comprising a plurality of track supports arranged in a grid pattern corresponding to the grid pattern of the track system, wherein each of the plurality of track supports is formed from a sheet metal blank having at least two bend lines to form a substantially U-shaped cross-section having upper and lower flanges and a vertical element extending between the upper and lower flanges, wherein one or more of the plurality of tracks are mounted on the track support structure.

[0021] As discussed above, the track system may include either an elongated track element in which the track is integrated into the upper flange of a substantially U-shaped cross-section formed from a sheet metal blank, or a track that is separate from and attachable to a track support having a substantially U-shaped cross-section formed from a sheet metal blank. Specifically, the separate track may be attachable to the upper flange of the U-shaped cross-section of the track support structure. Thus, in both track systems, a sheet metal blank is used to form the substantially U-shaped cross-section.

[0022] Sheet metal is versatile and can be processed in a variety of ways, including bending, punching, curling, and stamping. Sheet metal ensures uniform thickness before processing. Sheet metal is durable, has a high strength-to-weight ratio, and good malleability, allowing it to be formed into a variety of different configurations. Applying tension to sheet metal can improve its rigidity, allowing it to retain its formed shape. Specifically, bending sheet metal can introduce tension into sheet metal.

[0023] Each elongated track element or track support can be formed from a sheet metal blank by folding or bending the blank along at least two bend lines to form a U-shaped or substantially U-shaped cross-section. The bend lines can be mechanically marked, for example, by perforating the sheet metal blank or by marking with a marker pen. Alternatively, the bend lines can be unmarked and measured from one or both edges of the sheet metal blank's sides. A force is required to bend the sheet metal blank into the desired shape along each bend line. Specifically, the sheet metal blank is bent at a substantially 90° angle along a bend line (first linear axis) and then bent again at a substantially 90° angle along a second bend line (second linear axis) parallel to the first linear axis to form the U-shaped cross-section.

[0024] By bending the sheet metal blank along additional bend lines (i.e., more than two bend lines), it is possible to form raised and lowered regions in the upper flange of the U-shaped cross section. These raised and lowered regions form tracks in the upper flange, thereby integrating the tracks into the upper flange. Therefore, no extra material is required to form the tracks, and the integral tracks therefore provide a less complex track system compared to the prior art. This configuration minimizes the number of parts required to form the track system while maintaining structural integrity.

[0025] In contrast, when the track is mounted on the upper flange of the U-shaped section, the track can be made of any suitable material, such as metal or plastic, and can be made of a different material than the track support. Thus, the combination of different materials for the track support and the track can result in a mechanically improved track system overall.

[0026] There may be additional bend lines in the sheet metal blank to form protrusions or depressions in the substantially U-shaped cross section. Bending the sheet metal blank along the bend lines to form protrusions or depressions in the cross section can improve the rigidity of the formed shape.

[0027] The metal sheet blank may be stamped or punched to remove material from the blank to create notches in the metal sheet blank. The notches may be used, for example, to join two or more elongated track elements together and / or for screw holes for fastening separate components onto the elongated track elements. The stamping / punching process may occur before bending the sheet metal blank into a substantially U-shaped cross section.

[0028] Mechanically bending, pressing, or stamping a sheet metal blank requires the use of a press or other pressure-forming device to plastically deform the sheet metal blank. The sheet metal blank is bent along two or more bend lines. As the sheet is bent, the inner surface of the sheet metal blank shortens due to compression, while the outer surface of the sheet metal blank lengthens due to tension. Introducing tension into the sheet metal blank increases the rigidity of the formed metal. Compared to extrusion processes, which require high temperatures to feed liquid metal into a die, bending or stamping sheet metal blanks can be performed at much lower temperatures. By bending or stamping sheet metal blanks in this manner, the formed elements can have high dimensional accuracy and good product consistency at high speed and low cost.

[0029] A metal sheet blank is folded into a substantially U-shaped cross section. The U-shaped cross section has three sides: an upper flange, a lower flange, and vertical elements extending between the upper and lower flanges. By having three sided elongated track elements or track supports, material costs are reduced compared to four sided elongated track elements or track supports. Additionally, the weight of each elongated track element or track support is reduced compared to a four sided elongated track element of the same material. Considering the number of elongated track elements or track supports required for a track system, this weight reduction can be significant and can also result in an overall cost reduction.

[0030] Furthermore, by having a U-shaped or substantially U-shaped cross-section, the elongated track element or track support has improved structural integrity in both the x and y directions because the bend lines extend along the length of the elongated track element, providing stiffness both along the length of the elongated track element or track support and in a direction perpendicular to the length of the elongated track element or track support.

[0031] It is important that each of the plurality of elongated track elements and track supports be manufactured to tight dimensional tolerances because variations in dimensional tolerances of the elongated track elements or track supports, such as height, affect the connections between adjacent tracks, which in turn affect or create dimensional imbalances in the track surfaces of the tracks between adjacent tracks or track sections, creating one or more steps and / or gaps between adjacent tracks or track sections that can cause collisions between the wheels of a load handling device as it passes over adjacent track sections or junctions between tracks, resulting in wheel noise and vibration.

[0032] Instead of using an extrusion process, which requires high temperatures to deliver liquid metal to a die, the U-shaped cross section of an elongated track element or track support may be formed by cold rolling, by bending or stamping a sheet metal blank, which is performed at much lower temperatures. By bending or stamping a sheet metal blank in this manner, the formed element can have high dimensional accuracy and good product consistency at high speed and low cost.

[0033] Cold rolling strengthens metal sheet blanks by using mechanical stress to change the metal's microstructure as it is bent. Cold rolling, or work hardening, involves passing a sheet metal blank between two rollers that apply pressure to the sheet metal. This deforms the metal, elongating the grains within the metal and causing dislocations to accumulate in the bending deformation zone. This stops dislocation movement through the metal. Dislocations become entangled in the bending deformation zone, thus preventing further deformation in a particular grain unless significant energy is applied. This therefore increases the strength of the metal under further load. Furthermore, rolling sheet metal blanks at room temperature rather than at elevated temperatures reduces the cost of forming elongated track elements. Cold-rolled stainless steel can be manufactured with precision, allowing the metal to be manufactured to extremely tight tolerances. This is a particularly effective technique for bending metal without risk of breakage.

[0034] Optionally, the sheet metal blank comprises steel. Fabricating the track system, particularly the elongated track elements or track supports, from steel provides a high-strength and low-weight structure. Steel is also a ductile material ideal for mechanically bending into U-shaped cross sections. Preferably, the sheet metal blank may be formed from corrosion-resistant stainless steel or galvanized steel.

[0035] Optionally, the track is mounted on the upper flange by fasteners. The upper flange and / or the track may include fasteners for mounting the track to the upper flange. The track may be fastened directly onto the upper flange by using clips located on the upper flange or the track, or clips located on the track and, when located on the upper flange, the clips may interact with each other to hold the track on the upper flange. Alternatively, the track may be fastened to the upper flange by brackets attached to either the underside of the track and / or one or two sides of the track and / or the top surface of the track. If the brackets are attached to the top surface of the track, they do not interfere with the movement of the load handling device moving along the track. If the brackets are attached to one or two sides of the track, they may be bolted or screwed onto the track. If the brackets are attached to the underside of the track, they may be screwed or bolted to the underside of the track, or they may be clipped to the underside of the track.

[0036] Optionally, the fastener comprises one or more U-shaped brackets configured to clamp the upper flange to the track. The U-shaped bracket is configured to surround the track support such that the base of the U-shaped bracket is located below the bottom flange of the track support and one of the sides of the U-shaped bracket extends parallel to the vertical flange of the track support. Thus, when the U-shaped bracket is fitted to the track, it is sized and shaped to fit around the track support without leaving much room for the track support to move. The U-shaped bracket may be engageable with the underside of the truck, which reduces the possibility of the load handling device interacting with the bracket as it moves along the track. Preferably, the underside of the track comprises two protrusions located on either side of the underside and extending along the length of the underside of the track. Preferably, the U-shaped bracket is attachable to the two protrusions.

[0037] Optionally, the track includes a recess for receiving the track support. The recess may be sized and shaped to accommodate the size and shape of the upper flange of the track support. This recess allows for easy positioning of the track on the track support. The recess may be located on the underside of the track or may be formed between two protrusions located on either side of the underside and extending along the length of the underside of the track.

[0038] Optionally, the track comprises plastic. Plastic offers a lighter alternative to using metal. Using plastic materials to manufacture the track sections allows the track sections to be manufactured to tighter tolerances than can be achieved by extrusion alone. Using plastic materials to manufacture the track sections of the present invention allows the track sections to be injection molded. Unlike extrusion, injection molding allows parts to be formed to very tight tolerances, eliminating or reducing the need for excessive machining on the finished part. Furthermore, injection molding allows one or more profiles to be incorporated into the track with precise or intricate detail, which is essential for guiding the wheels of a load handling device on the track without the possibility of derailment. Optionally, the plastic track may be fastened to the top flange using an adhesive, and / or the track may be bolted onto the top flange. Specifically, the adhesive may be applied to the underside and / or top flange of the plastic track.

[0039] Optionally, the track is configured to snap onto the track support. The snap-fit ​​mechanism means that no excessive force is needed to fit the track onto the track support, and no tools are needed.

[0040] Optionally, the tracks comprise steel. Steel offers high strength at a light weight and is therefore ideally suited to provide support for load handling devices. In particular, the tracks may be cast steel, which offers a higher surface quality than other types of steel, and therefore a smoother surface on which the load handling devices can run. Furthermore, by casting the tracks, complex geometries and shapes can be incorporated into the tracks. The tracks may comprise, for example, galvanized steel or stainless steel.

[0041] Optionally, the track includes a raised central region extending along the longitudinal length of the track, the raised central region being positioned to allow one or more load handling devices to be guided along the track, and the raised central region may include radio frequency identification (RFID) sensors for informing the one or more load handling devices of their location within the track system.

[0042] Optionally, the track includes a pair of recesses extending side by side along the longitudinal length of the track, wherein the pair of recesses defines a path for one or more load handling devices. The pair of recesses may be formed between a raised central region and a pair of opposing ridges or lips. The opposing ridges may extend along the edges of the track or along the longitudinal length of the track. The opposing ridges prevent the load handling devices from becoming dislodged from the track. The pair of recesses has a width greater than the width of the wheels of the one or more load handling devices, allowing the one or more load handling devices to move along the pair of recesses.

[0043] Optionally, the plurality of tracks are subdivided into a plurality of track sections, each track section comprising a first track section element extending in a first direction and a second track section element extending in a second direction, each track section element being independently movable, and each of the plurality of track sections comprising a track element extending substantially transversely, such that relative movement between one or more of the plurality of track sections and the underlying track support structure is largely concentrated around a region of the track element extending from a node of the track section.

[0044] Optionally, each track section is formed as a single, integral body. By forming each track section as one or a single, integral body to provide a transversely extending track surface or track path, the number of track sections required to construct a track system is reduced compared to prior art grid structures, thereby simplifying the layout of the track sections on the grid structure. For example, there may be a one-to-one relationship between each of the multiple track sections and a single node in the grid structure, in the sense that only a single track section is required at each node of the grid structure. In prior art track systems, there is a two-to-one relationship between the number of track sections and a single node in the grid structure, in the sense that prior art systems have, at each node, one track section extending in a first direction and another, separate track section extending in a second direction. Thus, each of the multiple track sections may be cross-shaped, having a first track section element extending in a first direction and a second track section element intersecting the first track section element and extending in a second direction. The first and second track section elements may also be referred to as cross portions or branches of the track section. Being formed as a single or integral piece allows a track section to be attached to each node of the track supports where a first set of track supports intersects with a second set of track supports, thus allowing the track section to extend in both the first and second directions of the track system. This eliminates the need for separate track or rail elements extending in the first and second directions, as in prior art solutions. However, track sections are not limited to having a one-to-one relationship between the number of track sections and the number of nodes in the grid framework structure. For example, a single, integrally formed track section can be configured to extend across multiple nodes of the grid structure and further provide a laterally extending track surface.

[0045] Preferably, the plurality of track sections are arranged such that adjacent track sections contact between their respective intersections. The term "contact" encompasses abutment, connection, or engagement between adjacent track sections. The distal ends of the first and second track section elements of adjacent track sections may contact between their respective intersections. Optionally, the first and / or second track section elements of adjacent track sections contact at a midpoint or intermediate point between their respective intersections. This has the advantage that, instead of having multiple separate components, only track sections having a single size are required to cover a substantial portion of the grid member, thereby improving the manufacturability of the track sections, i.e., single tool design or one size fits all. When the grid cell is square, preferably, each track section of the plurality of track sections can have rotational symmetry in the horizontal plane with an order of rotational symmetry of four. With a 90° angle of rotational symmetry, a track section of the present invention can be rotated four times and still be consistent with itself. This provides the flexibility to attach the track sections of the present invention to a grid structure in multiple different orientations, thereby eliminating the "jigsaw" effect of assembling track, i.e., being limited to one orientation. In addition to simplifying the installation of multiple tracks on a track support structure, the cruciform configuration of the track sections allows the track sections to bridge the interface between adjacent modular storage cells to provide a continuous track surface that extends across the adjacent modular storage cells.

[0046] The ability to contact adjacent track sections between nodes or intersections of the grid structure also allows for different types or shapes of joints or connecting edges to be incorporated into the track sections. Preferably, the track sections are connected by a joint with a tapered edge to miter the wheels of the load handling device above and below. For purposes of this invention, the term "joint" is broadly interpreted to mean the adjacent ends of adjacent track sections. The contacting edges of adjacent track sections are cut or shaped to be mitered together. Preferably, the track sections are connected by a joint including a tapered edge. Before the wheels of the load handling device completely clear the edge of the track section element, a portion of the wheel already contacts the mitered edge of the track section element of the adjacent track section. This provides a gradual transition of the track joint, preventing a larger portion of the wheel from impacting the edge of the joint, further mitigating this above and below impact impact and reducing any noise and vibration of the wheels of the load handling device compared to a joint cut perpendicular to the direction of travel of the load handling device on the track. To further enhance the structural integrity of the joint connecting adjacent track sections to one another, the joint preferably comprises at least one tongue receivable in a correspondingly shaped groove. Preferably, the joint comprises an overlap joint.

[0047] However, the present invention is not limited to a one-to-one relationship between a single track section and the number of nodes in a track system. For example, a single, integrally formed track section may be configured to extend across multiple nodes in a track system and provide a laterally extending track surface.

[0048] A track system for a storage and retrieval system is provided that includes one or more load handling devices operable on the track system. a. a plurality of tracks arranged in a grid pattern for guiding one or more load handling devices operable on the track system; b. a plurality of track supports arranged in a grid pattern, the plurality of track supports comprising a first set of track supports extending in a first direction and a second set of track supports extending in a second direction, the second direction being substantially perpendicular to the first direction such that the first set of track supports intersect with the second set of track supports at one or more nodes in the track system, each of the plurality of track supports being formed from a sheet metal blank folded along a plurality of bend lines; Here, the first set of track supports intersect with the second set of track supports by the second set of track supports being received within one or more notches in the first set of track supports at one or more nodes in the track system.

[0049] The track system of the present invention allows multiple track supports to be easily and quickly mated together. For example, a first set of track supports may include two, three, four, or five cutouts to allow two, three, four, or five additional track supports to be accommodated in the first set of track supports. The cutouts may be cut into the track supports after the track supports are formed from a sheet metal blank. Alternatively, more conveniently, the cutouts may be cut into the sheet metal blank, which may then be folded to form the track supports. The cutouts may be formed by laser cutting the metal sheet blank. The metal sheet blank from which the track supports are formed may be stamped or punched to remove material from the blank to create one or more cutouts in the metal sheet blank. Thus, each track support may include two, three, four, or five cutouts, and thus a single track support may accommodate multiple vertically arranged track supports, e.g., two, three, four, or five track supports. The connection at the intersection of the first set of track supports and the second set of track supports includes, but is not limited to, a snap-fit ​​mechanism.

[0050] Optionally, one or more of the track supports of the first set snap onto one or more of the track supports of the second set at their intersections. For example, the profile of the cutout is shaped so that the first track support snaps and / or locks onto the second track support at their intersections. An advantage of forming the track supports from sheet metal blanks is that it is possible to incorporate a level of elasticity within the track supports to allow the track supports to snap onto one another.

[0051] Optionally, at least a portion of the cross-sectional profile of the notches of the first set of track supports corresponds to at least a portion of the cross-sectional profile of the second set of track supports. This allows at least a portion of the track supports of the second set to fit into the notches of the first set of track supports. Advantageously, this provides for easy and quick installation of the track system and limits the amount of (horizontal) movement of the second set of track supports within the notches of the first set of track supports, thereby creating a more stable surface for mounting the tracks. The cross-sectional profile of the notches of the first set of track supports may correspond to the cross-sectional profile of the second set of track supports. Alternatively, the cross-sectional profile of the notches of the first set of track supports may correspond to a portion, e.g., half, of the cross-sectional profile of the second set of track supports. In this configuration, the second set of track supports can advantageously be lowered onto the first set of track supports so that the second set of track supports are aligned with the notches of the first set of track supports. Alternatively, the first set of track supports and the second set of track supports may both include cutouts such that the cutouts in the first track supports connect with the cutouts in the second track supports when the track supports are arranged in a grid pattern. The cutouts in both the first and second sets of track supports may correspond to a portion, e.g., half, of the cross-sectional profile of the first and second sets of track supports.

[0052] Optionally, each of the plurality of track supports may have a substantially rectangular cross-section formed from a sheet metal blank bent along multiple bend lines. Advantageously, the rectangular corrugations formed from the sheet metal blank are rigid and have a high strength-to-weight ratio due to the multiple bends required to form the track support cross-section. The substantially rectangular cross-section includes a pair of parallel vertical sides connected by a horizontal element, wherein the parallel vertical sides include one or more notches. Thus, when a second track support is inserted into the vertical side or flange notch of the first track support, the second track support is positioned substantially perpendicular to the first track support, forming an intersection. Preferably, the second track support is positioned substantially 90 degrees relative to the first track support. Because the rectangular cross-section has two vertical sides, when a second set of track supports is received within one or more notches of the first set of track supports, the second set of track supports passes through two vertical sides of the first set of track supports, thereby providing stability at the node of the track system.

[0053] The track supports of the first set may have a height greater than that of the track supports of the second set. This configuration allows the track supports of the second set to fit into the track supports of the first set. Preferably, the track supports of the first set are 5% higher than the height of the track supports of the second set, or preferably, the track supports of the first set are 5% to 10%, or preferably, 10 to 15%, or preferably, 15% to 20%, or preferably, 20% to 25% higher than the height of the track supports of the second set. This configuration allows the track supports of the second set to be supported from all sides (particularly from the top and bottom) when positioned in one or more cutouts of the track supports of the first set. Shims may be mounted on the track support surfaces of the second track supports, and the tracks may be mounted on the shims and on the track support surfaces of the first track supports. In this configuration, the track covers the step formed at the intersection of the track supports, and the shim allows the track to be mounted on a surface that is flush with the track support surface of the first track support.

[0054] Multiple tracks may be mounted on multiple track supports. Thus, the multiple tracks are separated from the multiple track supports, allowing the tracks to be formed from a different material than the track supports. For example, the multiple tracks may comprise plastic, providing a lighter alternative to using metal. Using a plastic material to manufacture the track sections allows the track sections to be manufactured to tighter tolerances than can be achieved by extrusion alone. Using a plastic material to manufacture the track sections allows the track sections to be injection molded. Unlike extrusion, injection molding allows parts to be formed to very tight tolerances, eliminating or reducing the need for extensive machining on the finished part. Furthermore, injection molding allows one or more profiles to be incorporated into the track with precise or intricate detail, which is essential for guiding the wheels of a load handling device on the track without the possibility of derailment.

[0055] One potential drawback of using plastic trucks is the buildup of static electricity as the tires of load handling devices continuously travel on the truck. Static electricity can build up on the truck surface until it has an opportunity to discharge. In extreme cases, the buildup of static electricity on the truck can be large enough to cause harm when discharged through a person who comes into contact with the truck. To mitigate the buildup of static electricity on the truck, the truck is preferably made conductive to safely conduct the buildup of charge on the truck to ground. To maintain the benefits of injection molding truck sections from plastic, the truck is preferably made conductive by incorporating a conductive material into the plastic. It is known to incorporate various conductive materials into plastic materials to make them conductive. These include, but are not limited to, various types of carbon materials, such as micro- or nano-forms of graphite.

[0056] Alternatively, the tracks may comprise metal. In particular, the tracks may be formed from cast metal, which allows for complex geometries and shapes to be incorporated into the tracks. The tracks may comprise, for example, galvanized steel or stainless steel. Alternatively, the tracks may be formed from extruded aluminum.

[0057] Optionally, at least one free end of the folded sheet metal blank along the longitudinal length of the track support is folded inward to form at least one track support surface for mounting a track. Therefore, it is very easy to form the track support surface from the sheet metal blank. The folded sheet metal blank is folded inward to minimize the space required for the track support.

[0058] Optionally, at least one free end of the folded sheet metal blank includes a pair of opposing free ends to provide a pair of opposing track support surfaces for mounting tracks. This configuration provides increased stiffness over just folding one free end of the folded sheet metal blank, as the additional bending of the sheet metal blank introduces tension into the sheet metal blank.

[0059] Optionally, the pair of opposing free ends are spaced apart to provide a channel extending along the longitudinal length of the track support, thereby reducing the amount of material required to form the track support. The open channel also provides a way by which the track may engage with the track support.

[0060] Optionally, one or more cutouts in the first set of track supports have a profile that corresponds to the cross-sectional profile of the second set of track supports. Optionally, the second set of track supports have a cross-sectional area, and the one or more cutouts in the first set of track supports have a cross-sectional area, wherein the cross-sectional area of ​​the one or more cutouts in the first set of track supports is sized and shaped to be complementary to the size and shape of the cross-sectional area of ​​the second set of track supports. For example, the second set of track supports may have a substantially rectangular cross-sectional area, and the one or more cutouts in the first set of track supports may be sized and shaped such that the tracks of the second set precisely fit into the cross-sectional area of ​​the one or more cutouts. Alternatively, or additionally, the second set of track supports may have a cross-sectional area that includes one or more notches, and the cross-sectional area of ​​the one or more cutouts in the first set of track supports comprises one or more slots for receiving the one or more notches in the second set of track supports. Alternatively, or additionally, the track supports of the second set may have a cross-sectional area with one or more slots, and the cross-sectional area of ​​the one or more cutouts of the track supports of the first set includes one or more notches for accommodating the one or more slots of the track supports of the second set.

[0061] Having a cross-sectional area that is complementary to the one or more notches in the second track support and the first track support allows the second track support to be more easily fed or slid into the one or more notches in the first track support, allowing an installer to easily identify where the second track support should be inserted into the first track support and the orientation of the second track support, and ensuring that movement between the second track support and the first track support is minimized once the second track support is in place within the one or more notches in the first track support.

[0062] Optionally, each of the track supports has an H-shaped cross-sectional profile. The H-shaped cross-sectional profile is formed from a single sheet metal blank. The single sheet metal blank may be roll-formed to form the track supports. Roll-forming is a cost-effective method of forming track supports, resulting in little material waste. An advantage of having an H-shaped cross-sectional profile is that each track support can be inverted to have a similar cross-sectional profile to a non-inverted track support. This means that track supports with an H-shaped cross-sectional profile can be used throughout a track system without the need for other types of track supports (especially those with different cross-sectional profiles). The heights of all of the H-shaped track supports within a track system may also be the same or substantially the same, so that tracks can be supported on either inverted or non-inverted track supports.

[0063] The H-shaped cross-sectional profile may include a pair of opposing vertical sides, a pair of horizontal flanges, and a U-shaped portion centrally and internally located between the pair of opposing vertical sides. The U-shaped portion may include a pair of vertical edges extending parallel to and inward from the pair of vertical sides and a horizontal edge extending between the pair of vertical edges. The horizontal edges may be positioned approximately in the center of the H-shaped cross-sectional profile and may provide a connection surface for attaching the track support to an underlying horizontal bracing member. The horizontal edges of the first track support may also be used as a resting surface against which the horizontal edges of a second track support vertically disposed relative to the first track support may rest at a node. Alternatively or additionally, the horizontal edges of the second track support may be used as a resting surface against which the horizontal edges of a first track support vertically disposed relative to the second track support may rest at a node or intersection.

[0064] The cross-sectional profile of the first set of track supports may be the same as the cross-sectional profile of the second set of track supports, meaning the same track supports can be used throughout the track system, thereby saving manufacturing and installation costs. For example, the second set of track supports may have the same H-shaped cross-sectional profile as the first set of track supports, but in an inverted position.

[0065] Optionally, each of the track supports includes a track connection portion for connecting to the tracks, and the second set of track supports includes one or more notches, and each intersection of the track system is formed by assembling the second set of tracks with the first set of track supports in a substantially vertical direction so that their respective track connections are flush or level. This configuration ensures that the tracks are supported on a horizontal surface (i.e., no steps are formed at nodes throughout the grid pattern of the track system). This means that when the tracks are positioned on the track supports, they are all at the same height as each other, and therefore multiple load handling devices operating on the tracks can move smoothly over the tracks. To assemble the track supports into the grid pattern, the second set of tracks can be lowered onto the first set of tracks when one or more notches in the second set of track supports align with one or more notches in the first track support. Thus, the positioning of the notches on both the first and second sets of track supports provides a self-jigging mechanism so that the first and second sets of track supports can be easily assembled in the correct position, thereby providing positional accuracy and helping to speed up installation.

[0066] The one or more cutouts may each have a height corresponding to approximately half the height of the track supports, which allows the one or more cutouts of the second set of track supports to fit into the one or more cutouts of the first set of track supports while maintaining the respective track support surfaces flush so that a smooth surface is present for mounting the tracks.

[0067] Optionally, the first set of track supports may be rotated about their longitudinal axes so that one or more notches face upward. The set of track supports with one or more notches facing upward may be referred to as the "second set of track supports." The set of track supports with one or more notches facing downward may be referred to as the "first set of track supports." Thus, the same track supports may be used throughout the track system, and the upward-facing notches of the rotated first set of track supports may interface with the downward-facing notches of the first set of track supports to create a grid pattern.

[0068] The multiple tracks may be secured to the multiple track supports using fasteners or adhesive. Preferably, each of the multiple track supports may include multiple slots spaced apart in a direction along the longitudinal length of the track support, and each of the multiple tracks may include multiple tabs for engaging with the multiple slots of the track support to prevent the multiple tracks from disengaging from the multiple track supports. For example, the tabs may be configured to snap onto the track support such that the tabs are deflected and positioned to be received within the slots of the track support, thereby securing the multiple tracks to the multiple track supports. Other forms of securing the track sections to the track supports besides snap-fit ​​joints are possible, such as the use of fasteners or adhesives.

[0069] Optionally, each of the slots is sized to allow at least a portion of each of the plurality of tracks to move in a direction along the longitudinal length of the respective track support, and each slot may be enlarged in one or more directions to allow movement of each tab within each slot of the track support.

[0070] Optionally, the track is oriented so that the length of each slot extends along the longitudinal length of the track support. For example, each slot may be oriented so that the longest edge of the slot extends along the longitudinal length of the track support and the shortest edge (i.e., the width of the slot) extends in a direction substantially perpendicular to the longitudinal length of the track support. The orientation and configuration of each slot is such that a tab engaged with the slot can move along the slot, thereby allowing thermal expansion or contraction of the track element attached thereto relative to the underlying track support. Similarly, expansion or contraction of the underlying track support as a result of thermal expansion will likely cause the slot to move relative to the tab engaged therein.

[0071] Optionally, each of the plurality of tracks is configured to snap-fit ​​onto a respective one of the plurality of track supports, the snap-fit ​​between the plurality of tracks and the plurality of track supports being configured such that the connection allows one or more of the tracks to expand or contract along a substantially horizontal direction, i.e., along a plane in which the track system lies, but is prevented from moving substantially vertically to prevent track sections from becoming dislodged from the underlying track support.

[0072] Optionally, the plurality of tracks are subdivided into a plurality of track sections, each track section comprising a first track section element extending in a first direction and a second track section element extending in a second direction, the first track section element being movable relative to the second track section element on the track support when mounted in the plurality of slots. Each track section element is capable of independent movement. Each of the plurality of track sections comprises a track element extending substantially transversely, such that relative movement between one or more of the plurality of track sections and the underlying track support structure is largely concentrated around a region of the track element extending from a node of the track section. A node within a track section is an area where track elements within a given track section intersect, and the node experiences minimal movement between the track section and the underlying track support structure.

[0073] Optionally, each track section is formed as a single, integral body. By forming each track section as a unitary or single, integral body to provide a transversely extending track surface or track path, the number of track sections required to construct a track system is reduced compared to prior art grid structures, thereby simplifying the layout of the track sections on the grid structure.

[0074] A grid framework structure for a storage and retrieval system is provided. The grid framework structure comprises: a track system as described above; a support framework structure supporting the track system; and a stack of containers disposed within a storage column located below the track system.

[0075] The grid framework structure comprises steel, such as galvanized steel or stainless steel. In particular, the support framework structure that supports the track system may comprise steel, such as galvanized steel or stainless steel.

[0076] The supporting framework may be assembled from multiple prefabricated panels or frames. For definition purposes, the term "prefabricated" in the context of grid framework structure construction is interpreted to encompass manufactured sections of the grid framework structure prior to assembly on-site, such that the grid framework structure can be assembled at a location distinct from the manufacture of the prefabricated sections of the grid framework structure, where each prefabricated section comprises multiple parts or components of the grid framework structure. The different locations may be locations remote from the location where the grid framework structure is assembled, i.e., in a different building, or may be assembled at the same location but in different areas of the same site, e.g., different areas of the same building. The prefabricated modular panels are load-bearing in the sense that, when assembled together to form the supporting framework structure, they provide a load-bearing structure for supporting one or more load handling devices traveling on a track system attached to the supporting framework structure. Having each prefabricated modular panel extend in a single plane also facilitates the ability to pack the supporting framework structure flat for transportation. Prefabrication of modular panels allows for rapid assembly of the supporting framework structure on-site or within a building. This has the advantage that the supporting framework structure can be constructed within an existing, empty building or warehouse.

[0077] Typically, a grid framework structure is a linear structure comprising a central section, a peripheral section, and corner sections. Different sections of the grid structure require track sections of different shapes, with different numbers of track section elements arranged in different positions. For example, corner sections of the grid structure require track sections with two laterally extending track section elements corresponding to the corners of the linear structure. Similarly, for peripheral sections of the grid structure, the track sections comprise an elongated track section element and one or more track section elements branching laterally from the elongated track section element. For central sections representing a larger portion of the grid structure, each track section of the plurality of track sections is generally cross-shaped, with first and second laterally extending track section elements. In all of the different sections of the grid structure, the relationship between the track sections at the nodes and the grid structure can still optionally be one-to-one, eliminating the need for separate track or rail elements extending separately in the first and second directions of the grid structure. Similarly, the track section elements or branches of the track sections in different areas or sections of the grid structure extend laterally.

[0078] The term "tracks" may also be interpreted to encompass an assembly of a first set of parallel tracks extending in a first direction and a second set of parallel tracks extending in a second direction.

[0079] Optionally, the track system further comprises one or more anti-crush devices, wherein the one or more anti-crush devices are inserted between the support framework structure and the track system comprising the track supports. The one or more anti-crush devices may be positioned between nodes of the track system, where the track supports typically are not well supported. In particular, when each track support of the first and second sets of track supports extends across the entire length or width of the track system, it is useful to support sections of the track supports between the intersections, where the weight of the load handling device can potentially cause sagging or bending in these areas. Therefore, by providing anti-crush devices along the length and width of the track system, the track supports are provided with additional support to withstand the weight of the load handling device operating above. In particular, the anti-crush devices may be positioned below or within the U-shaped portion of a track support having an H-shaped cross-sectional profile, thereby supporting the horizontal edge of the track support, which may be substantially centered within the H-shaped track support. One or more anti-crush devices may rest on the underlying horizontal bracing members, and the track supports may rest on the one or more anti-crush devices.

[0080] The one or more anti-crush devices may comprise steel, and in particular, the one or more anti-crush devices may comprise cast steel. Cast steel is mechanically strong and can be easily formed into most shapes and sizes. The anti-crush devices may be galvanized to prevent rusting.

[0081] One or more anti-crush devices may be attachable to the underlying supporting framework structure and track support. The one or more anti-crush devices may be attachable to the supporting framework structure and track support, respectively, by screws or bolts and nuts. The screws or bolts may extend or pass through the height of the anti-crush device. Alternatively, each anti-crush device may be attachable to the supporting framework structure and track support by two screws that fit into threaded openings in the anti-crush device, such that one threaded opening extends from the top surface of the anti-crush device and one threaded opening extends from the bottom surface of the anti-crush device, such that the two threaded openings are separated from each other. Thus, to attach the anti-crush device to the underlying supporting framework structure, a screw is fitted through a hole in the supporting framework structure and fitted into a threaded opening extending from the bottom surface of the anti-crush device, and to attach the anti-crush device to the track support, a screw is fitted into a hole in the track support and fitted into a threaded opening extending from the top surface of the anti-crush device.

[0082] The one or more anti-crush devices may extend in the same direction as the track support above the one or more anti-crush devices. For example, the one or more anti-crush devices may extend in the y-direction if the track support and underlying horizontal bracing member extend in the y-direction, and / or the one or more anti-crush devices may extend in the x-direction if the track support and underlying horizontal bracing member extend in the x-direction. The one or more anti-crush devices may each have an elongated shape such that each anti-crush device is long relative to its width, thus requiring fewer anti-crush devices along the length of each track support and horizontal bracing member.

[0083] Optionally, each of the one or more anti-crush devices includes at least one raised positioning feature, and each of the plurality of track supports and the underlying supporting framework structure includes one or more holes for receiving the at least one raised positioning feature of the one or more anti-crush devices. The receiving holes in the supporting framework structure (especially the horizontal bracing members) allow for easy identification of where to place each anti-crush device, thereby enabling faster installation of the grid framework structure. Furthermore, because the raised positioning feature allows each anti-crush device to be inserted into position within the receiving hole, and thus the anti-crush devices are limited to movement along at least the horizontal / longitudinal direction of their respective track supports, the raised positioning feature means that the one or more anti-crush devices do not need to be attached to the underlying track support or horizontal bracing member with screws or bolts. Each of the one or more anti-crush devices may include a single raised positioning feature, which may be located, for example, in the center of the anti-crush device. The single raised positioning feature may extend from the top surface to the bottom surface of the crush-resistant device such that the raised positioning feature rises above the top surface of the crush-resistant device and extends below the bottom surface of the crush-resistant device.

[0084] The at least one raised positioning feature may comprise a pair of raised positioning features on a top surface of the crush-resistant device and a pair of raised positioning features on a bottom surface of the crush-resistant device. The pair of raised positioning features may be located on opposite sides of the crush-resistant device.

[0085] Each of the one or more crush-resistant devices may include a plurality of raised positioning features. Each raised positioning feature may include a dome protruding from a top surface of the crush-resistant device and / or a bottom surface of the crush-resistant device. Each raised positioning feature may be positioned differently on the top surface compared to the bottom surface of the crush-resistant device. For example, there may be three raised positioning features protruding from the top surface of the crush-resistant device and five raised positioning features protruding from the bottom surface of the crush-resistant device. Alternatively, there may be three raised positioning features protruding from the top surface of the crush-resistant device and positioned on one side of the crush-resistant device, and three raised positioning features protruding from the bottom surface of the crush-resistant device and positioned on the opposite side of the crush-resistant device. The raised positioning feature on the top surface may be a different shape than the raised positioning feature on the bottom surface, for example, the raised positioning feature on the top surface may have a triangular profile and the raised positioning feature on the bottom surface may have a square profile, and the holes in the track support and horizontal bracing member are shaped to accommodate the profile of the raised positioning feature of the anti-crush device.

[0086] The one or more anti-crush devices may comprise a plurality of anti-crush devices. Optionally, the plurality of anti-crush devices may be spatially distributed in a direction along the length of the track system and / or supporting framework structure. The anti-crush devices may be evenly distributed, i.e., positioned at regular intervals. Alternatively, the anti-crush devices may be unevenly distributed, e.g., with more anti-crush devices located closer to the center of the length of each track support.

[0087] Optionally, one or more anti-crush devices are positioned between nodes in the track system, thus providing additional support to the track supports, particularly U-shaped portions of track supports having an H-shaped cross-sectional profile, in areas where the track supports may sag or buckle due to the weight of load handling devices operating above.

[0088] A storage and retrieval system comprising the grid framework described above and one or more load handling devices for lifting and moving containers stacked in stacks, each load handling device comprising: a wheel assembly for moving the load handling device on a track system; a container receiving space positioned above the track system; A lifting device is provided which is arranged to lift a single container from the stack into the container receiving space.

[0089] These and other aspects of the present invention will now be described, by way of example only, with reference to the accompanying drawings. [Brief explanation of the drawings]

[0090] [Figure 1] FIG. 1 is a schematic diagram of a known grid framework structure. [Figure 2] FIG. 2 is a schematic diagram of a top view showing a stack of bins arranged within the framework structure of FIG. [Figure 3] FIG. 3 is a schematic diagram of a load handling device operating on a grid framework structure. [Figure 4] FIG. 4 is a schematic perspective view of a load handling device showing a lifting device gripping a container from above. [Figure 5] 5(a)(b) are schematic perspective cutaway views of the cargo handling device of FIG. 4, where (a) shows a container accommodated within the container receiving space of the cargo handling device, and (b) shows the container receiving space of the cargo handling device. [Figure 6] FIG. 6 is a plan view of a section of a known grid structure with four adjacent grid cells showing that the intersections or nodes of the grid members are supported by vertical uprights, with each grid cell forming a storage column. [Figure 7]FIG. 7 is a perspective view showing four vertical uprights that make up a storage space or storage column within a grid framework structure. [Figure 8] FIG. 8 is a perspective view showing an arrangement of tracks and track supports interconnected at nodes or intersections by cap plates. [Figure 9] FIG. 9 is a perspective view of a track support or grid member. [Figure 10] FIG. 10 is a perspective view of a cap plate for interconnecting vertical uprights to grid members at nodes. [Figure 11] FIG. 11 is a perspective cross-sectional view of the interconnection of vertical uprights to grid members by cap plates at nodes. [Figure 12] FIG. 12 is a perspective view of a track or rail. [Figure 13] FIG. 13 is a perspective view showing the assembled grid framework structure. [Figure 14] FIG. 14 is a perspective view showing the track system attached to a support structure. [Figure 15] FIG. 15 is a diagram of the arrangement of track sections in a track system. [Figure 16(a)] FIG. 16(a) is a perspective view of an elongated track element. [Figure 16(b)] Figure 16(b) is a cross-sectional profile of the elongated track element of Figure 16(a). [Figure 16(c)] FIG. 16(b) is a diagram of a sheet metal blank used to form the elongated track element of FIGS. 16(a) and 16(b). [Figure 17(a)] FIG. 17(a) is a perspective view of an insert being inserted into the elongated track element of FIGS. 16(a) and 16(b). [Figure 17(b)] FIG. 17(b) is a perspective view of an insert that is inserted into two elongated track elements, thereby joining the two elongated track elements. [Figure 18(a)]FIG. 18(a) is a perspective view of an insert being inserted into three elongated track elements to form a four-way branch. [Figure 18(b)] FIG. 18(b) is a perspective view of three elongated track elements of FIG. 18(a) joined together using inserts to form a four-way joint or intersection. [Figure 19(a)] FIG. 19(a) is a perspective view showing two elongated track elements mating with each other to form a four-way branch or intersection. [Figure 19(b)] FIG. 19(b) is a perspective view of two elongated track elements of FIG. 19(a) mated together to form a four-way bifurcation or intersection. [Figure 20(a)] FIG. 20(a) is a perspective view of a track system including a track and track supports and brackets. [Figure 20(b)] FIG. 20(b) is a cross-sectional profile of the assembled track system of FIG. 20(a). [Figure 20(c)] Figure 20(c) is a diagram of a sheet metal blank used to form the track support of Figures 20(a) and 20(b). [Figure 21(a)] FIG. 21(a) is a perspective view of a further track system comprising a track and a track support. [Figure 21(b)] FIG. 21(b) is a cross-sectional profile of the assembled track system of FIG. 21(a). [Figure 21(c)] Figure 21(c) is a diagram of a sheet metal blank used to form the track support of Figures 21(a) and 21(b). [Figure 22] FIG. 22 is a perspective view of a further track support. [Figure 23(a)] FIG. 23(a) is a side view of the track support of FIG. [Figure 23(b)] FIG. 23(b) is a perspective view of the track support of FIGS. 22 and 23(a) intersecting with a second track support. [Figure 24]FIG. 24 is an enlarged perspective view of the intersection between the track support and the second track support of FIG. 23(b). [Figure 25] FIG. 25 is a perspective view of the track system mounted on the track support of FIGS. 22 to 24. [Figure 26] FIG. 26 is a perspective view of a shim mounted on a track support of a track system. [Figure 27(a)] Figure 27(a) is a perspective view of a track section for mounting on the track support of Figures 22 to 26. [Figure 27(b)] Figure 27(b) is a perspective view of the track section of Figure 27(a) inverted. [Figure 28] FIG. 28 is a perspective view of a plurality of track sections of FIG. 27 mounted on the track support of FIGS. 22 to 26. [Figure 29(a)] FIG. 29(a) is a cross-sectional profile of an alternative embodiment of a track support. [Figure 29(b)] Figure 29(b) is a side view of the track support of Figure 29(a). [Figure 29(c)] Figure 29(c) is a side view of the track support of Figures 29(a) and (b) flipped / rotated 180 degrees about the longitudinal axis of the track support. [Figure 30(a)] Figure 30(a) is a side view of the track support of Figures 29(a) and 29(b) intersecting the track support of Figure 29(c). [Figure 30(b)] FIG. 30(b) is an enlarged view of the intersection shown in FIG. 30(a). [Figure 30(c)] FIG. 30(c) is a cross-sectional profile of the intersection shown in FIGS. 30(a) and 30(b). [Figure 31(a)] FIG. 31(a) is a perspective view of the crush-resistant device. [Figure 31(b)] FIG. 31(b) is a top view of the crush-resistant device of FIG. 31(a). [Figure 32] FIG. 32 is a side view of an anti-crush device positioned on a horizontal bracing member. [Figure 33(a)] FIG. 33(a) is a perspective view of a further embodiment of an anti-crush device. [Figure 33(b)] FIG. 33(b) is a top view of the crush-resistant device of FIG. 33(a). [Figure 34(a)] FIG. 34(a) is a perspective view of two anti-crush devices positioned on a horizontal bracing member. [Figure 34(b)] FIG. 34(b) is a perspective view of four anti-crush devices positioned on a horizontal bracing member. [Figure 35(a)] FIG. 35(a) is a perspective view of the anti-crush device in position between the track support and the horizontal bracing member. [Figure 35(b)] FIG. 35(b) is a perspective view of the anti-crush device in position between the track support and the horizontal bracing member rotated 180° along its longitudinal axis. DETAILED DESCRIPTION OF THE INVENTION

[0091] The following embodiments represent preferred examples of how to implement the present invention, but they are not necessarily the only examples of how this may be achieved. These examples are described in sufficient detail to enable one skilled in the art to practice the present invention. Other examples may be utilized, and structural changes may be made, without departing from the scope of the present invention, as defined in the appended claims. Furthermore, directional references and any other terms having an implied direction are provided by way of example to aid the reader's understanding of the specific examples described herein. They should not be construed as requirements or limitations, particularly with respect to the location, orientation, or use of the present invention, unless specifically recited in the appended claims. Similarly, connection references (e.g., attached, coupled, connected, joined, fixed, etc.) should be interpreted broadly and may include intermediate members between connections of elements and relative movement between the elements. Thus, connection references do not necessarily imply that two elements are directly connected and in a fixed relationship to each other, unless specifically recited in the appended claims. Similarly, the phrase "movement in the n-direction," where n is one of x, y, and z (and related phrases) is intended to mean movement substantially along or parallel to the n-axis in either direction (i.e., toward the positive end of the n-axis or toward the negative end of the n-axis).

[0092] The present invention builds upon known features of storage systems, such as the grid framework structure and load handling devices described above with reference to Figures 1 to 5.

[0093] Figure 6 shows a top view of a section or portion of a conventional track system 40 comprising four adjacent grid cells 42, and Figure 7 shows a perspective side view of a single grid cell 42 supported by four vertical uprights 16 to form a single storage column 44 for stacking and storing one or more containers 10. The grid framework structure can be thought of as being divided into a supporting framework structure comprising a plurality of vertical uprights and a track system. The track system comprises a plurality of grid members supported by the supporting framework structure and arranged in a grid pattern comprising a plurality of grid cells.

[0094] FIG. 6 illustrates a series of horizontal intersecting beams or grid members 18, 20 arranged to form a plurality of rectangular frames that make up grid cells 42; more specifically, a first set of grid members 18 extending in a first direction and a second set of grid members 20 extending in a second direction, with the second set of grid members 20 running transversely to the first set of grid members 18 in a substantially horizontal plane; i.e., the track system is represented by Cartesian coordinates in the X and Y planes. The terms "vertical uprights," "upright members," and "upright columns" are used interchangeably in this description to mean the same thing. For purposes of describing the present invention, points or branches where grid members cross or intersect may be defined as nodes or intersections 50, as indicated by the shaded squares in FIG. 6 . From the layout of at least a portion or section of a known track system 40 that makes up four adjacent grid cells 42 shown in FIG. 6 , it is clearly apparent that each intersection or node 50 of the track system 40 is supported by a vertical upright 16. From the section or at least part of the track system 40 shown in FIG. 6, four adjacent grid cells are supported by nine vertical uprights 16, i.e., three sets of vertical uprights 16 supporting the track system in three rows, each row comprising three nodes 50.

[0095] Each grid member may include a track support 18, 20 and / or a track or rail 22a, 22b (see FIG. 8), whereby the track or rail 22a, 22b is attached to the track support 18, 20. A load handling device is operable to move along the track or rail 22a, 22b of the present invention. Alternatively, the track 22a, 22b may be integrally formed with the track support 18, 20 as a single unit, for example, by extrusion. At least one grid member in the set, for example, a single grid member, may be subdivided or segmented into individual grid elements that can be joined or linked together to form the grid members 18, 20 extending in the first or second direction. When a grid member includes a track support, the track support may also be subdivided into individual track support elements that are linked together to form the track support. Individual track support elements that make up the track supports extending in the first and second axial directions are shown in FIG. 8. Individual track support elements 56 used to make up the track supports 18, 20 are shown in FIG. 7. The track support element 56 in Figure 9 is a double back-to-back C-section bolted together.

[0096] A connecting plate or cap plate 58, as shown in FIG. 10 , can be used to link or join individual track support elements 56 together in both a first direction and a second direction at branches where multiple track support elements intersect in the track system 40; i.e., the cap plate 58 is used to connect the track support elements 56 together to the vertical uprights 16. As a result, the vertical uprights 16 are interconnected at their upper ends by the cap plates 58 at branches where multiple track support elements intersect in the track system 40; i.e., the cap plates are located at nodes 50 of the track system 40. As shown in FIG. 10 , the cap plate 58 is cross-shaped with four connection portions 60 for connecting to any point along the length or end of the track support elements 56 at the intersections 50 of the track support elements 56. The interconnection of the track support elements to the vertical uprights at the nodes by the cap plates 58 is illustrated in the cross-sectional profile of the node 50 shown in FIG. 11 . The cap plate 58 includes a spigot or protrusion 62 sized to fit snugly within the hollow section 46 of the vertical upright 16 to interconnect multiple upright columns to the track support elements, as shown in FIG. 11 . Also shown in FIG. 11 are track support elements 56 a, 56 b extending vertically in both the first direction (x-direction) and the second direction (y-direction). The connecting portions 60 are perpendicular to each other to connect to the track support elements 56 a, 56 b extending in the first and second directions. The cap plate 58 is configured to be bolted to the ends of the track support elements 56 a, 56 b or along the length of the track support elements. Each of the track support elements 56 a, 56 b is positioned to interlock with each other at nodes to form the track system 40. To accomplish this, the distal or opposing end of each of the track support elements 56 a, 56 b includes a locking feature 64 for interconnecting with a corresponding locking feature 66 on an adjacent track support element.The opposing or distal end of one or more track support elements includes at least one hook or tongue 64 receivable within a notch or slot 66 located midway along an adjacent track support element 56 at the branch where the track support elements meet in the track system 40. Referring back to FIG. 9 in conjunction with FIG. 11, the hooks 64 at the end of the track support element 56 are shown received within an opening 66 in an adjacent track support element that extends across the vertical upright 16 at the branch where the track support elements 56 meet. Here, these hooks 64 are provided through openings 66 on both sides of track support element 56b. The openings 66 are located halfway along the length of the track support element 56, such that, when assembled together, adjacent, parallel track support elements 56 in the first and second directions are offset by at least one grid cell. This is shown in FIG. 8.

[0097] To complete the track system 40, tracks 22a, 22b are attached to the track support elements 56 once the track support elements 56 are interlocked to form a grid pattern with track supports 18 extending in a first direction and track supports 20 extending in a second direction. The tracks 22a, 22b are either fitted and / or snap-fit ​​onto the track supports 18, 20 in a slide-fit arrangement (see FIG. 8). Similar to the track supports, the tracks include a first set of tracks 22a extending in a first direction and a second set of tracks 22b extending in a second direction, the first direction being perpendicular to the second direction. The first set of tracks 22a is subdivided into a plurality of track elements 68 in the first direction such that, when assembled, adjacent parallel track elements in the first direction are offset by at least one grid cell. Similarly, the second set of tracks 22b is subdivided into multiple track elements 68 in the second direction such that, when assembled, adjacent track elements in the second direction are offset by at least one grid cell. This is shown in Figure 8. An example of a single track element 68 is shown in Figure 12. As with the track support elements, multiple track elements in the first and second directions are laid together to form tracks in both directions.

[0098] As can be seen from the above description, the process of assembling a grid framework structure, which involves erecting vertical uprights, connecting grid members, and installing tracks, is very time-consuming due to the multiple separate components required to assemble the grid framework structure. The process of erecting a grid framework structure can take weeks; in the worst case scenario, the process can take months. As demand for e-commerce rapidly grows, especially in the retail sector, there is an increasing demand for distribution centers, also known as customer fulfillment centers (CFCs), in more locations than just a few serving major cities to meet the growing demand from customers. The presence of distribution centers in more locations also has the effect of shortening the time required to complete last-mile logistics for the movement of goods from distribution centers to their final destinations. Such last-mile logistics is also an important consideration for keeping perishable goods, such as food products, fresh at their final destinations. One of the major bottlenecks to establishing distribution centers in more locations is the time and cost required to build the grid framework structure. Not only are the time and cost of constructing a grid framework structure a cause for concern when establishing a distribution center, but the grid framework structure should have the flexibility to be assembled at several existing locations, including existing warehouses, rather than custom-built warehouses purely to accommodate the grid framework structure.

[0099] The above problems are alleviated by forming the track system from fewer structural components than currently practiced above, while maintaining the structural integrity of the track system for supporting the weight of one or more robotic load handling devices operating on a grid framework structure.

[0100] A track system 73 is provided for guiding the movement of one or more robotic load handling devices on the support framework structure 71. The combination of the track system 73 and the support framework structure 71 is referred to as a grid framework structure 70, as shown in FIG. 13 . When assembling the grid framework structure 70, the support framework structure 71 is assembled first, and then the track system 73 is attached to the support framework structure 70. The track system 73 is elevated above the ground by the support framework structure 71, creating an open storage space for storing multiple stacks of storage containers. The support framework structure 71 or the track system 73, or both the support framework structure 71 and the track system 73, can be assembled from modular structural components. In the particular embodiment shown in FIG. 13 , both the support framework structure 71 and the track system 73 are assembled from prefabricated modular structural components to form the three-dimensional grid framework structure 70. Each of the prefabricated frames includes a plurality of vertical members 74 braced by horizontal bracing members 72. As shown in Figures 13 and 14, there is both an upper horizontal bracing member 72A that forms the frame to which the track system 73 is attached, and a lower horizontal bracing member 72B that, together with the upper horizontal bracing member 72A, increases the stiffness of the supporting frame structure 71.

[0101] The track system 73 is attached to the supporting framework structure 71 such that the track system extends across the plurality of prefabricated modular storage cells, as shown in Figure 13. The track system 73 includes a plurality of tracks 75 arranged in a grid pattern comprising a plurality of grid cells 77. More specifically, the track system 73 includes a first set of parallel tracks 75a extending in a first direction and a second set of parallel tracks 75b extending in a second direction, the second direction being substantially perpendicular to the first direction so as to adopt the grid pattern.

[0102] Different areas of the track system 73 where the track system has a linear configuration are shown in the sketch of the track section pattern in Figure 15. The sketch of the track section pattern shown in Figure 15 is not to scale and is for illustrative purposes only. Track sections 250 in corner sections 250b of the track system 73 are shown with different shaded areas, and each of the track sections 250b in the corners has two track elements 254, i.e., two branches. Track sections in peripheral sections 250c of the track system 73 are shown with different shaded areas. As shown in Figure 15, each of the track sections 250c around the track has three track elements 254, i.e., three branches. In the embodiment illustrated in FIG. 15 , a peripheral track section 250 c can have two track elements 254 extending in opposite directions along a first direction and a third track element 254 extending in a second direction, or two track elements 254 extending in opposite directions along the second direction and a third track element 254 extending in the first direction. The track sections 250 c in the peripheral section are not limited to having three track elements or branches 254 and can include more than three track elements, depending on whether the peripheral section extends across two or more nodes 300. A node 300 represents an area of ​​the track system 73 where elements or branches of individual track sections 250 intersect. For example, a peripheral section can include two track elements extending in opposite directions along a first direction and multiple track elements, i.e., more than three branches, extending in a second direction to connect to or intersect with adjacent track sections in the central section of the grid structure.

[0103] As is clearly evident in the schematic diagram shown in FIG. 15 , a substantial portion of the track system resides within the central section of the track, with each of the track sections 250 being cross-shaped with track elements branching or extending in a first direction (X) and a second direction (Y). For all of the differently shaped track sections 250, 250b, 250c in the particular embodiment shown in FIG. 15 , there is a one-to-one relationship between each of the multiple track sections and each of the nodes 300 in the track system. For example, there is a one-to-one relationship between track section 250b and the corner nodes 300 of the track / grid structure. Similarly, there is a one-to-one relationship between each of track sections 250c and each of the peripheral nodes 300 in the track system.

[0104] However, the present invention is not limited to a one-to-one relationship between each of the multiple track sections and each of the nodes, as a single track section can extend across two or more nodes in the track system. For example, the branches or track elements 254 of one or more track sections 250 can be sized to extend across one or more nodes of the track system. Larger track section 250 sizes mean that fewer track sections 250 are required to configure, i.e., assemble, the track system 73. The distal ends 252 of one or more of the track elements 254 of adjacent track sections extend to meet between the nodes of the track system 73 because this is an area of ​​the track system where the underlying track support is less susceptible to any vertical displacement. In all cases, each track section 250, 250b, 250c is a single, integral piece with its laterally extending portion or element 254 to provide a track surface or path for load handling devices to travel on the laterally extending track system. A single-piece track section having laterally extending track surfaces or paths significantly reduces the complexity and components required to assemble a grid framework structure in accordance with the present invention. A variety of materials can be used to manufacture the track sections. These include various metals, such as aluminum, plastics, such as nylon, and / or composite materials.

[0105] While the track system 73 shown in FIG. 15 primarily depicts cross- and T-shaped track sections 250, the track system can also be formed from multiple elongated track elements. One embodiment of an elongated track element is shown in FIG. 16. The elongated track element 90 is formed from a sheet metal blank 96, shown in FIG. 16(c). The sheet metal blank 96 is bent along bend lines 97 to form a substantially U-shaped cross section. The bend lines divide the sheet metal blank into three sections, which, when bent, form a bottom flange 91, a vertical element 93, and a top flange 95. The top flange 95 forms the track 94. The top flange 95, vertical element 93, and bottom flange 91 function as track supports, i.e., the track is integral with the track supports, as shown in FIG. 16(a). In FIG. 16(c), the bend lines 97 are formed as perforations extending parallel to the longitudinal length of the elongated track element 90. Two bend lines 97a form the basis of the U-shaped cross section and divide the sheet metal blank into three sections. An additional bend line 97b, located on the top flange 95 when folded, forms the track, as shown in Figure 16(c). Figure 16(c) also shows bend line 97c, located near the free end of the metal sheet blank 96, allowing the free end to bend inward, thereby forming a substantially U- or C-shaped elongated track element cross section.

[0106] When formed from a metal sheet blank, the track 94 includes a central raised region 98 for guiding a load handling device along the track system. The central raised region 98 extends along the longitudinal length of the track 94. Additionally, the track 94 includes opposing ridges or lips 99 extending along the edges of the track 94 and extending along the longitudinal length of the track 94. The opposing ridges 99 act as retainers to ensure that a load handling device traveling along the track does not move off the track. While it is not necessary to have opposing ridges 99 on the track, as having the central raised region 98 is sufficient to guide the load handling device, the opposing ridges 99 further ensure that the load handling device continues to travel along its designated course. The combination of the central raised region 98 and the ridges 99 extending along the longitudinal length of the elongated track element creates a pair of side-by-side recesses 101 extending along the longitudinal length of the elongated track element. The pair of recesses 101 create a path for the load handling device to travel, meaning that the wheels of the load handling device are contained within the pair of recesses and it is difficult for the wheels to move out of the recesses onto a different course. The width of the recesses is wide enough so that the wheels of the load handling device do not rub against the central raised area 98 and / or the opposing ridges 99.

[0107] As shown in Figures 16(a) and 16(c), there is an aperture 102 located within the track. The aperture is positioned so that a radio frequency identification (RFID) sensor can be located below the aperture, allowing the sensor to communicate with load handling devices that pass above the RFID sensor. This allows the load handling devices to be tracked and their locations recorded on the grid framework structure 70.

[0108] The elongated track elements 90 are joined together by inserts 80, as shown in Figure 17(a). The inserts 80 are rectangular shaped to fit within the elongated track elements. The size (height and width) of the inserts 80 is determined by the size of the cross section of the elongated track elements 90. The inserts 80 have a height and a width that are slightly smaller than the height and width of the cross section of the elongated track elements 90, so that the elongated track elements 90 can slide over the inserts 80, but there is some resistance between the elongated track elements 90 and the inserts 80, which means that the inserts 80 cannot be easily removed from the elongated track elements 90. To join two elongated track elements 90a, 90b together so that the elongated track elements extend in the same direction, as shown in Figure 17(b), inserts 80 are inserted into both the end of the first elongated track element 90a and the end of the second elongated track element 90b, so that the respective ends of the first and second elongated track elements are connected or abutted against each other. Thus, multiple track elements can be connected in a single direction in this manner.

[0109] The elongated track elements 90 can also be joined to one another by inserts 80 to form a four-way branch, or node, or intersection, or nodal point, as shown in FIG. 18 . The branch includes three elongated track elements: a first elongated track element 90a, a second elongated track element 90b, and a third elongated track element 90c. The third elongated track element 90c includes an opening 72 positioned to receive the insert 80 oriented perpendicular to the longitudinal length of the third track element 90c. Specifically, the opening 72 has a height and width greater than the height and width of the insert 80, thereby allowing the insert 80 to fit within the opening 72 and be restricted from moving horizontally or vertically within the opening. The longitudinal length of the insert 80 is greater than the width of the third elongated track element 90c. Thus, when the insert 80 is positioned within the opening 72 of the third elongate track element 90c, the insert extends beyond the third elongate track element 90c such that the second elongate track element 90b can be fitted to one free end of the insert 80 and the first elongate track element 90a can be fitted to the second free end of the insert 80. Thus, the first elongate track element 90a and the second elongate track element 90b are connected together in a manner similar to that shown in Figure 17, but in Figure 18 the first and second elongate track elements sandwich the third elongate track element 90c between them, as shown in Figure 18(b).

[0110] Alternatively, elongated track elements 90 can be joined to form a four-way branch, node, or intersection, as shown in FIG. 19 . In contrast to FIG. 18 , which requires three elongated track elements to form a four-way branch, in FIG. 19 , only two elongated track elements are required to form a four-way branch; no inserts are required. Furthermore, in FIG. 18 , the elongated track elements are mated with each other by horizontally moving the insert and elongated track elements, whereas in FIG. 19 , the elongated track elements are mated with each other by vertically moving the elongated track elements. In FIG. 19 , a first elongated track element 100 a includes a notch 74 in its upper flange. Furthermore, similar to the first elongated track elements shown in FIGS. 17 and 18 , the first elongated track element includes a vertical element (not shown) and a folded free end 78 aligned parallel to the vertical element of the first elongated track element 100 a. The second elongated track element 100b includes a pair of slots 76 in a vertical element extending between the upper and lower flanges. The second elongated track element 100b is oriented in a first direction, and the first elongated track element 100a is oriented in a second direction perpendicular to the first direction. To connect the first elongated track element with the second elongated track element, the second elongated track element 100b is pressed down onto the first elongated track element 100a so that one of the pair of slots 76 is aligned with and fully engages the vertical element and the folded free end 78 of the first elongated track element 100a. The first elongated track element 100a has the same height as the second elongated track element 100b, so that when the two elongated track elements are interlocked with each other, as shown in FIG. 19(b), the integrated tracks are the same height. Additionally, the track of the second elongated track element 100b includes an island 125 at the intersection between the first and second elongated track elements to allow a load handling device to change direction at the intersection.

[0111] In contrast to track systems having tracks integrated into the top flange of the U-shaped cross section as shown in Figures 17 to 19, it is also possible to have track systems where the tracks are separate from the track support and the tracks are attached to the track support. Examples of track systems with separate tracks and track supports are shown in Figures 20 and 21.

[0112] In FIG. 20, the track system 130 includes a track support 111 and a separate track 113. The track support 111 is formed from a metal sheet blank, as shown in FIG. 20(c). The metal sheet blank 110 includes bend lines 107 indicating where the metal sheet blank needs to be bent to form a U-shaped cross-section. To form the U-shaped cross-section, bending along only two bend lines 107a is necessary. However, as shown in FIG. 20(c), additional bend lines can be incorporated into the metal sheet blank. In particular, the additional bend line 107c is located near the free ends of the metal sheet blank 110, allowing the free ends of the metal sheet blank to be bent inward toward each other to form a substantially U-shaped or substantially C-shaped cross-section. As shown in FIG. 20(c), the metal sheet blank 112 can be bent into a shape that forms a bottom flange 114, a vertical element 115, and a top flange 116. The bottom flange 114, the vertical element 115, and the top flange 116 may have the same width x in the sheet metal blank, or the top and bottom flanges may have a shorter width compared to the vertical element. The width x of the top flange 116 needs to be able to fit under the track 113.

[0113] The track shown in Figure 20 is specifically a track section similar to track section 250 shown in the center section of Figure 15. Track section 113 in Figure 20 is cross-shaped with track elements branching or extending laterally, i.e., in a first direction (X) and a second direction (Y). There is a one-to-one relationship between each of the multiple track sections and each of the nodes 300 in the track system. For example, there is a one-to-one relationship between track section 250b and the corner nodes 300 of the track / grid structure.

[0114] The track section 113 shown in FIG. 20(a) includes an upper surface 118 and a lower surface 119. The upper surface 118 includes a raised central portion 108 extending along the longitudinal length of the track and a pair of opposing ridges or lips 109 extending parallel to the edges of the longitudinal length of the track. Between the raised central portion 108 and the pair of opposing ridges 109 are a pair of recesses 112 extending side-by-side along the longitudinal length of the track, creating a path for a load handling device to travel. The track section 113 of FIG. 20(a) extends both laterally and vertically and is formed as a single body. The track section includes nodes or intersections 124 where laterally extending track elements meet vertically extending track elements. The junction 124 lacks a raised central portion and instead has isolated raised cubes or islands 125 that allow load handling devices to change direction at the junction 124. Although the track section in Figure 20(a) is shown as having a junction and track elements of equal length, it is possible to have track elements of unequal lengths. The underside 119 of the track section includes a recess 126 into which the upper flange 116 of the track support 111 can fit. Protrusions 127 on either side of the recess 126 mean that the track section cannot move laterally when positioned on the upper flange 116 of the track support 111.

[0115] The track system 130 of FIG. 20 also includes brackets 120. The brackets are U-shaped such that each bracket includes a horizontal base element 121, a pair of vertical elements 122 extending from each end of the horizontal base element 121, and a pair of horizontal fixing points 123. The horizontal fixing points 123 extend horizontally from each of the free ends of the vertical elements 122. When the underside 119 of the track section 113 is fitted onto the top flange 116 of the track support 111, the bracket 120 can be fitted such that the horizontal base element 121 of the bracket 120 supports the bottom flange 114 of the track support 111 and one of the pair of vertical elements 122 of the bracket extends parallel to and adjacent to the vertical element 115 of the track support 111. The brackets 120 are fastened to the underside 119 of the track sections, specifically, to each of the protrusions 127 on the underside of the track section 113, as shown in FIG. 20(b). In Figure 20, two brackets are used to fasten track section 113 to track support 111. Specifically, one bracket 120 is used to fasten one track element to the track support.

[0116] FIG. 21 illustrates a further embodiment of a track system 140. The track system 140 includes a track support 145 and a track subdivided into track sections 141. The track support 145 has a U-shaped cross-section and includes a bottom flange 144, a vertical element 146, and a top flange 148. The top flange 148 and the bottom flange 144 face each other. The track support 145 is formed from a metal sheet blank 142, as shown in FIG. 21(c). The metal sheet blank 142 includes a bend line 147a for bending the metal sheet blank into a U-shaped cross-section. To form the U-shaped cross-section, the metal sheet blank only needs to be bent along two bend lines. As shown in FIG. 21(c), there is an additional bend line 147b for bending the free end of the metal sheet blank inward. FIGS. 21(b) and 21(c) illustrate that the vertical element 146 has a width x that is greater than the bottom flange 144 and the top flange 147. However, the vertical element 146 may alternatively have the same width as the bottom flange 144 and the top flange 148 .

[0117] The track section 141 includes a raised central region 143 and is mounted directly onto an upper flange 148 of the track support 145. Specifically, the track section 141 may be glued onto the track support, or as shown in Figure 21(b), the track section 141 may be bolted or screwed onto the upper flange 148 of the track support. The track 141 may be made of plastic or metal.

[0118] 21(a) shows that three track supports (first track support 135a, second track support 135b, and third track support 135c) are required to form a four-way branch, intersection, or node in the track system. Specifically, a bracket 150 comprising an upper flange (not shown), a lower flange 151, and a vertical element 152 extending between the upper and lower flanges 144 is connected to the second track support 135b such that the lower flange 151 of the bracket 150 is fastened to the lower flange 144 of the second track support 135b and the upper flange of the bracket 150 is fastened to the upper flange 148 of the second track support 135b. The vertical element 152 of the bracket 150 is then bolted to the vertical element 146 of the first track support 135b, whereby the first track support 135a and the second track support 135b are fastened to one another at 90 degrees to form an intersection, specifically a T-junction. Similarly, the same bracket attached to the first and second track supports 135a, 135b is used to fasten the third track support 135c to the first track support 135a to form a cross-shaped intersection.

[0119] The second track support 135b and the third track support 135c are positioned so that both the second and third track supports 135b, 135c are perpendicular to the first track support 135a, and so that the second and third track supports extend in the same direction and along the same path. The first track support 135a can extend the entire length of the grid framework structure, and the other track supports can be bolted onto the vertical elements at appropriate points along the first track support. As shown in Figure 21(a), the nodes do not have tracks that would allow the load handling device to change direction.

[0120] FIG. 22 illustrates a further embodiment of a track support. The track support 160 includes a base horizontal element 161, a pair of vertical side surfaces 162, and a pair of horizontal raised flanges 163. The base horizontal element 161 and the pair of vertical side surfaces 162 together form a U-shaped cross section. The pair of horizontal raised flanges 163 are formed by bending the free ends of a bent sheet metal blank inward so that the free ends extend toward each other and form a track support surface 165 to which a track can be attached. Thus, the combination of the base horizontal element 161, the pair of vertical side surfaces 162, and the horizontal raised flanges 163 forms a substantially rectangular cross section. However, the pair of horizontal raised flanges 163 do not meet. Instead, the track support surface 165 includes an open channel 166 extending along the longitudinal length of the track support 160. A downwardly extending element 167 extends from the horizontal raised flanges 163 toward the base horizontal element 161. Downwardly extending elements 167 define the sides of open channel 166. Track support 160 also includes slots or notches 168 on vertical side 162. Slots 168 are relatively evenly spaced in FIG. 22, with each slot extending along a portion of the longitudinal length of track support 160. Slots 168 provide a means of engagement between the track and the track support.

[0121] The track support 160 of Figure 22 may be formed from a metal sheet blank, for example, by cold rolling. As shown in Figure 22, there are four bends near the support surface 165. Having multiple bends near the support surface 165 increases the stiffness of the track support 160, particularly within the support surface 165.

[0122] As shown in FIG. 23(a), the track support 160a of FIG. 22 includes a pair of vertical side surfaces 162 having cutouts 175. The cutouts 175 have a profile that corresponds to the cross-sectional profile of the second track support 160b, thereby allowing the second track support 160b to be inserted into the cutouts 175, thereby forming an intersection between the first track support 160a and the vertical second track support 160b. In particular, the cutouts 175 are substantially rectangular, and the cutouts are shaped to engage with the open channel 166, the downward extension element 167, and the support surface 165 of the second track support 160b. Thus, the interaction between the shape of the cutouts 175 of the first track support 160a and the downward extension element 167 and the support surface 165 of the second track support 160b creates a guide mechanism for fitting and sliding the two track supports together. The cutout 175 is completely defined by the first track support 160a such that when the second track support 160b is inserted into the cutout 175, the second track support 160b is supported vertically (from below and above) and horizontally (from both sides) by the first track support 160a. When the second track support 160b is inserted into the cutout 175, the horizontal base element 161 of the second track support 160b rests on the horizontal base element 161 of the first track support 160a.

[0123] The height of the second track support 160b is smaller than the height of the first track support 160a so that the second track support 160b fits into the cutout 175 of the first track support 160a. Thus, in the track system, the first set of track supports 160a extending in a first direction have a specific height, and the second set of track supports 160b extending in a second direction have a specific height that is smaller than the height of the track supports of the first set. Other than the height difference between the first set of track supports 160a and the second set of track supports 160b, the first set of track supports 160a and the second set of track supports 160b have identical characteristics. The second set of track supports 160b may or may not have a cutout such as the cutout 175 shown in FIG. 23(a).

[0124] As shown in FIG. 23(b), the second track support 160b is inserted into the notch 175 of the first track support 160a so that a junction or node 177 is formed centrally along the longitudinal length of the second track support. The notch 175 is formed with two identical apertures 176, one in each vertical side 162 of the first track support 160a, as shown in FIG. 24. In the track system, the second track support can have a length of 0.5 m to 1 m, or 1 m to 1.5 m, or 1.5 m to 2 m, or greater than 2 m, and thus can pass through one or more first track supports. Similarly, the first track support can have a length of 0.5 m to 1 m, or 1 m to 1.5 m, or 1.5 m to 2 m, or greater than 2 m, and can include one or more notches to receive one or more second track supports. Thus, overall, the track system has few track supports extending over a large area, thereby minimizing labor and material costs.

[0125] The first track support 160a is taller than the second track support 160b, so that when the second track support is inserted into the notch 175 of the first track support, a step 178 is formed at the interface between the first track support and the second track support. The step 178 is shown in FIG. 24. The step 78 may be less than 10 mm or less than 5 mm, which, while small, can cause difficulties for load handling devices traveling along the path of the second track support 160b. To solve this problem, as shown in FIG. 25, separate tracks 180 are attached to the track supports 160a, 160b. The tracks 180 are arranged to extend laterally and vertically to form a track intersection. The tracks 180 are mounted to rest on the track support surface 165a of the higher first track support 160a. To prevent the tracks from becoming unbalanced and tilting vertically toward the lower second track support 160b, shims 182 are attached to the track support surface 165b of the second track support 165b (shown in FIG. 26), and the tracks 180 are mounted on the shims 182 and on the track support surface 165a of the first track support 160b. The track thus covers the steps formed at the intersections or nodes 177 of the track supports, and the shims 182 allow the track 180 to be mounted on a surface that is level with the track support surface 165a of the first track support 160a.

[0126] In the context of this application, the term "track" can be interpreted to encompass an assembly of a first set of parallel tracks extending in a first direction and a second set of parallel tracks extending in a second direction. The track or tracks are subdivided into a plurality of track sections, each track section comprising a first track section element extending in the first direction and a second track section element extending in the second direction. Thus, the term "track" can also be interpreted to encompass individual track sections.

[0127] FIG. 27 shows the same track 180 as FIG. 25. Specifically, the track includes a track section 180a for mounting to a track support surface on a track support. The track section is formed as a single, integral body in that the track section includes a first track section element 181 extending in a first direction and a second track section element 182 extending in a second direction, the second direction being perpendicular to the first direction, thereby creating a cross-shaped track section. Each of the track section elements includes a raised central portion 183 and a pair of opposing ridges 184. Between the raised central portion 183 and the pair of opposing ridges are a pair of recesses 186 extending side by side along the longitudinal length of the track. The pair of recesses defines a path for one or more load handling devices.

[0128] To allow one or more load handling devices to intersect at an intersection or junction of track sections, i.e., at a crossroad corresponding to a node of the track system, the track intersection or junction comprises small islands 185 as shown in Figure 27(a) to allow the wheels to be guided laterally. This is particularly the case in areas where tracks intersect or meet, i.e., areas that lie mainly around the central section of the track system.

[0129] While having cruciform track sections helps mitigate unevenness in the underlying track support structure, the distal ends of the track section elements of adjacent track sections are also susceptible to unevenness, especially when they contact between nodes. The distal ends of the track elements 181, 182 create a step at the junction between adjacent track sections 180a, which, if left unchecked, can cause vertical displacement of the wheels of a load handling device traveling across the junction between the connecting adjacent track sections. To mitigate this step, the distal ends of the track section elements 181, 182 are mitered or tapered, as shown in Figures 27(a) and 27(b). The junction between adjacent track sections includes at least one tapered edge 188 that changes the traditional 90° angle cut to a substantially 45° angle cut edge. Thus, before the wheels of the load handling device roll completely over the edge of the first track section, a portion of the wheels already contacts the mitered end 188 of the second track section. This provides a gradual transition between adjacent track sections and prevents the wheels from sinking into any gaps between the distal ends of adjacent track section portions.

[0130] To secure multiple tracks to a track support structure, each track section can be snap-fit ​​to the track support. As shown in FIG. 27(b), the underside of a track section includes one or more lugs or tabs 190 configured to snap-fit ​​into the track support 160. The one or more lugs 190 can include beads or protruding edges arranged to be flexibly received in a snap-fit ​​arrangement within one or more slots 168 in the opposing vertical sidewalls (or vertical lateral surfaces) 162 of the track support 160, as shown in FIG. 28. The snap-fit ​​feature can be a cantilever snap-fit. However, other forms of snap-fit ​​connections commonly known in the art for securing track sections to track supports are applicable to the present invention. Similarly, other forms of securing track sections to track supports other than snap-fit ​​joints, such as the use of fasteners or adhesives, are also applicable to the present invention.

[0131] In addition to the thermal expansion of the different components of the support framework structure and the track support structure described above, one or more of the tracks in the plurality of tracks are also subject to thermal expansion. This is particularly true when the plurality of tracks are separately attached to the track support. When the track is made of a plastic material and the track support is primarily made of metal, a thermal expansion coefficient mismatch occurs between the track and the underlying track support to the extent that differential movement occurs between the two components as a result of thermal expansion. Because each of the plurality of track sections includes track elements that extend substantially transversely, relative movement between one or more of the plurality of track sections and the underlying track support structure is largely concentrated around the area of ​​the track elements extending from the node of the track section. A node within a track section is an area where the track elements in a given track section intersect. When the plurality of tracks are rigidly secured to the underlying track support structure, differential movement between one or more of the plurality of tracks and the underlying track support as a result of differential thermal expansion between the track and the track support can distort one or more of the tracks. For example, if the underlying track support thermally expands more than the tracks, forces resulting from the thermal expansion of the track support may tend to affect the connection between the tracks and the track support. In the worst case, the difference in thermal expansion between the tracks and the track support may result in failure of the connection between the tracks and the track support, ultimately leading to delamination or detachment of one or more tracks from the track support. When multiple track sections are snap-fitted onto a track support structure, failure of the connection between one or more of the multiple tracks and one or more of the underlying track supports occurs primarily at the snap-fit ​​joint between the multiple tracks and the track support structure.

[0132] To mitigate relative movement between the plurality of tracks and the underlying track support structure as a result of thermal expansion, the connection between each of the track sections 180 a and the underlying track support structure 160 comprises a slip or movement joint. If the connection between each of the plurality of track sections 180 a and the underlying track support structure 160 comprises a snap-fit ​​joint, the snap-fit ​​joint between the track section and the track support is configured such that the connection allows one or more of the track elements 181, 182 to expand or contract along a substantially horizontal direction, i.e., along the plane in which the track system lies, but is prevented from moving substantially vertically to prevent the track section 180 a from disengaging from the underlying track support 160. To accommodate the thermal expansion joint within the snap-fit ​​joint, one or more slots 168 in the opposing vertical sidewalls 162 of the track support 160 are enlarged in one or more directions to allow movement of the lug or tab 190 within the one or more slots 168 of the track support 160. As shown in FIG. 22 , each slot 168 is oriented so that its longest edge extends along the longitudinal length of the track support 160 and its shortest edge (i.e., the width of the slot) extends in a direction substantially perpendicular to the longitudinal length of the track support. The slot orientation is such that a lug or tab 190 engaged with the slot 168 allows the lug or tab 190 to move along the slot 168, which in turn allows the track elements 181, 182 attached thereto to expand or contract relative to the underlying track support 160. Similarly, expansion or contraction of the underlying track support 160 as a result of thermal expansion is likely to cause the slot 168 to move relative to the lug or tab 190 engaged therein. There are various other means for incorporating a slip or movement joint into the connection between one or more of the multiple tracks and the underlying track support structure. For example, the connection between each of the multiple tracks and the underlying track support structure can include one or more runners, such as telescoping drawer runners.Another means of providing one or more slip joints in the connections between multiple track sections, particularly each of the track elements of the track sections, includes replacing one or more slots in the opposing side walls of the track support with recesses extending along the longitudinal length of the track support and configured to cooperate with lugs or tabs on the track in a sliding arrangement. Similar to the one or more slots, one or more tabs or lugs on the track section are configured to snap fit with the recesses.

[0133] To accommodate thermal expansion of one or more of the track sections in the track system, the distal ends of the track elements 181, 182 of adjacent track sections 180a are spaced apart. This spacing is sufficient to allow the track elements of adjacent track sections to expand on the underlying track support and connect or join without buckling their respective distal ends. This spacing also depends on the diameter of the wheels of a robotic load handling device operable on the track system. If the spacing between the distal ends of adjacent track elements is too large compared to the diameter of the wheels, this can introduce a step between the adjacent track elements, causing the wheels of the robotic load handling device to get caught on or bump into the ends of the track elements, and in the worst case, cause the wheels to sink or fall into the gap created by the spacing between the adjacent track elements. This spacing should be sufficient to allow the wheels of the robotic load handling device to traverse the gap formed by the spacing between the distal ends of adjacent track sections without excessive wheel snagging, but not so large that the wheels sink or fall into the gap. The spacing between the distal ends of adjacent track elements of adjacent track sections within the track system is comparable to the spacing between adjacent vertical uprights of adjacent prefabricated frames within the supporting framework structure, i.e., the spacing ranges from 0.5 mm to 3 mm, preferably 1 mm to 2 mm, and more preferably 1.5 mm to 2 mm. The spacing between the distal ends of the track elements is significantly affected by the thermal expansion of one or more prefabricated frames within the supporting framework structure. Typically, for wheels with a diameter of approximately 120 mm, the spacing can be up to 6 mm without the wheels excessively jamming or sinking within the gap.

[0134] A further embodiment of a track support is shown in FIG. 29. The track support 460 is formed from a sheet metal blank. In particular, the sheet metal blank comprises steel, preferably galvanized steel. The sheet metal blank used to form the track support of FIG. 29 is roll-formed into an H-shape, as shown in FIG. 29(a). The track support 460 comprises a pair of vertical sides 462, a pair of horizontal flanges 463, and a U-shaped portion 465 centrally located within the track support 460. The U-shaped portion comprises a pair of vertical edges 466 extending parallel to and within the pair of vertical sides 462. The U-shaped portion 465 also comprises a horizontal edge 467 extending between the pair of vertical edges 466. Specifically, the horizontal edge 467 is positioned approximately in the center of the H-shape with respect to both the width and height of the H-shaped track support.

[0135] The track support 460 comprises an upper portion 470 and a lower portion 472. The upper portion 470 comprises a pair of horizontal raised flanges 463, a U-shaped portion 465, and approximately half the height of each of the vertical sides 462. The lower portion 472 comprises approximately half the height of each of the vertical sides 462. The vertical sides 462 comprise indentations 474 on both the upper portion 470 and the lower portion 472 to increase the rigidity of the track support. The free ends of the vertical sides 462 are bent inward to further increase the rigidity of the track support and to create a horizontal base comprising a pair of horizontal base flanges 475.

[0136] Each track support is elongated in that it extends in either the x- or y-direction depending on the direction it is oriented. In particular, the track support 460 shown in FIG. 29(a) extends in the x-direction. The track support may have a length of four grid cells, which is equal to approximately 2.2 m to 3.1 m. Each track support 460 includes at least one cutout 478. As shown in FIG. 29(b), which is a side view of the track support of FIG. 29(a) along the x-direction, there may be multiple cutouts 478 spaced along the length of the track support (in the x-direction). Each track support 260 may have 2, 3, 4, 5, 6, 7, 8, 9, or 10 cutouts 478. The track support 460 includes multiple pairs of protrusions 468, each pair of protrusions projecting into a respective one of the cutouts 478 to create a profile corresponding to a portion of the cross-sectional profile of the H-shaped track support. While FIG. 29(b) shows the notches 478 facing downward, as shown in FIG. 29(c), the same track support 460 can be rotated 180° about its longitudinal axis so that the notches 478 face upward. The same track supports can be used throughout a track system, such that a second set of track supports 460A extending in a second direction have upward-facing notches 478 (as shown in FIG. 29(c)) and a first set of track supports 460 extending in a first direction have downward-facing notches 478 (as shown in FIG. 29(b)), where the second direction is substantially perpendicular to the first direction. The track supports of the first set intersect with the tracks of the second set at one or more nodes in the track system, and vice versa, which is achieved by mating each notch of the track supports of the first set with each notch of the track supports of the second set.

[0137] FIG. 30 more clearly illustrates the coupling of the notches 478 of the vertically extending track supports. FIG. 30(a) illustrates a second track support 460A extending in a second direction (in this case, the y-direction) and a first track support 460 extending in a first direction (the x-direction), where the second direction is substantially perpendicular to the first direction. The second track support 460A includes upwardly facing notches 478A, and the first track support 460 includes downwardly facing notches 478. Each downwardly facing notch 478 of the first track support 460 mates with each upwardly facing notch 478A of the second track support 460A at each node. This interaction can be achieved by aligning the downward notch 478 of the first track support 460 with the upward notch 478A of the second track support 460A and then lowering the first track support 460 in a substantially vertical direction onto the second track support 460A. Specifically, as shown in FIGS. 30(a) to (c), the U-shaped portion 465 of the first track support 460 rests on the U-shaped portion 465A of the second track support 460A. The vertical side 462 defining the notch 478 on the first track support 460 contacts the vertical side 462A defining the notch 478A of the second track support 460A, thus reducing movement of the first track support 460 along the second direction. Notably, the profile of each notch 478 corresponds to half the height of a track support. The protrusion 468 on the vertical side 462 of the track support 460 is positioned and shaped to fit within and / or around the recess 474 in the vertical side of the vertically positioned track support. Beneath the U-shaped portion of the second track support 460A is an anti-crush device 480, shown more clearly in FIG. 31. The anti-crush device is located away from the node or intersection of the track support. The anti-crush device 480 is a cast steel component that allows the second support track 460A to be connected to the horizontal bracing member. As shown in FIG. 30(c), a portion of the anti-crush device 480 fits within a hole 466 in the track support 460A, specifically within the horizontal edge 467 of the U-shaped portion 465 of the second track support 460A.

[0138] 31(a) and (b) illustrate the anti-crush device 480 in isolation. The anti-crush device 480 is an elongated component comprising a pair of raised positioning features 494 on a top surface 490 of the anti-crush device and a pair of raised positioning features 494 on a bottom surface 492 of the anti-crush device. One raised positioning feature 494 is located at each free end of the anti-crush device, and each raised positioning feature 494 extends vertically (in the z-direction). The pair of raised positioning features 494 on the bottom surface 492 are shaped to fit within holes 76 formed in the top surface of the upper horizontal bracing member 72A. This is shown in FIG. 32. Similarly, the pair of raised positioning features 494 on the top surface 490 are shaped to fit within holes 466 in the track support 460. The hole 466 in the track support 460 is positioned at the horizontal edge 467 of the U-shaped portion, specifically the U-shaped portion 465, as shown in Figure 30(c).

[0139] The crush-resistant device includes openings 482 extending from a top surface 490 to a bottom surface 492, i.e., the openings extend in the z (vertical) direction. One opening 482A is centrally positioned along the length (x-direction) of the crush-resistant device. A pair of openings 482B is positioned within raised positioning features 494 on either side of the crush-resistant device, and thus extends down the raised positioning features 494 from the top surface 490 to the bottom surface 492 in the z (vertical) direction. Each opening 482 includes threads (not shown) that can be mated with a (threaded) screw or bolt, so that the crush-resistant device can be attached to an overlying track support and an underlying horizontal bracing member by a screw or bolt and nut. Alternatively, each opening 482 extending from either the top surface 490 or the bottom surface 492 may extend along a portion of the height (z-direction) of the crush-resistant device. For example, each opening may extend along substantially half or substantially one-third of the height of the anti-crush device such that the openings 482 in the top surface 490 of the anti-crush device 480 do not connect to the openings 482 in the bottom surface 492 of the anti-crush device. In this configuration, a screw or bolt may be used to connect the anti-crush device to the overlying track support through the openings in the top surface 490 of the anti-crush device, and a separate screw or bolt may be used to connect the anti-crush device to the underlying horizontal bracing member 72A through the openings in the bottom surface 492 of the anti-crush device. As shown in FIG. 31 , the central opening 482A has a larger diameter than the pair of openings 482B in the raised positioning feature 494, such that a larger bolt or screw may be used in the central opening compared to the bolts used in the pair of openings 482B in the raised positioning feature 494.

[0140] In an alternative embodiment of the anti-crush device, as shown in Figures 33(a) and (b), the anti-crush device does not include screws or bolt holes, but has the same size and shape as the anti-crush device shown in Figures 31(a) and (b). In this configuration, one or more anti-crush devices simply rest on the underlying horizontal bracing members, and track supports rest on the one or more anti-crush devices. The raised locating features 494 in this embodiment are particularly useful because they allow the anti-crush devices to fit onto the horizontal bracing members to hold them in place thereon, and allow the track supports to fit onto the anti-crush devices to prevent longitudinal movement of the anti-crush devices.

[0141] The anti-crush devices are designed to be positioned to extend in the same direction as the length of the horizontal bracing members. For example, an anti-crush device is positioned to extend in the x direction along a horizontal bracing member extending in the x direction, and an anti-crush device is positioned to extend in the y direction along a horizontal bracing member extending in the y direction. This is shown in FIG. 34(a), where two anti-crush devices 480 are oriented to extend in the x direction and connect to a horizontal bracing member 72A that also extends in the x direction. FIG. 34(b) shows a complete horizontal bracing member 72A extending in the x direction and four anti-crush devices 480 positioned on top of the horizontal bracing member 72A, also extending in the x direction. As previously mentioned, the anti-crush devices 480 are positioned away from the nodes between the vertical track supports. Instead, they are positioned directly on the horizontal bracing member and below a single track support that extends in the same direction as the horizontal bracing member. To accommodate this, there are two anti-crush devices of different sizes, particularly different heights, used throughout the grid framework structure. As described above with reference to FIG. 35(a), when the second track support 460A is positioned on the horizontal bracing member 72A, the U-shaped portion 465 is inverted, as also shown in FIG. 30(c). The anti-crush device 480 is positioned between the horizontal bracing member 72A and the inverted U-shaped portion 465A such that the anti-crush device is located within the inverted U-shaped portion 465A. Further, with reference to FIG. 35(b), when the first track support 460 is positioned on the horizontal bracing member 72A, the U-shaped portion 465 is in a non-inverted orientation, such that the anti-crush device is located below the U-shaped portion 465. When the U-shaped portion 465 is in the non-inverted orientation (shown in FIG. 35(b)), the height d1 of the interior space within the U-shaped portion is less than the height d2 of the space below the U-shaped portion. The height difference between d1 and d2 is due to the thickness x of the sheet metal used to form the track support. The thickness x of the sheet metal is 1.5 mm to 2 mm, preferably 1.6 mm. Therefore, the height d2 of the space under the U-shaped portion 465 when the U-shaped portion is in the non-inverted orientation is d1 + x.Thus, anti-crush devices 480 having height d1 are used under the second set of track supports 460A, and anti-crush devices 480 having height d2 are used under the first set of track supports 460.

[0142] While efforts have been made to draw attention to those features of the invention which are considered to be particularly important, it is to be understood that applicant claims protection for any patentable feature or combination of features referred to in this specification and / or shown in the drawings, whether or not specifically emphasized. Many variations and modifications not expressly described above are possible without departing from the scope of the invention as defined in the appended claims.

[0143] Further features of the present invention may be described with reference to the following numbered clauses:

[0144] Clause 1. A track system for a storage and retrieval system comprising one or more load handling devices operable on the track system, said track system comprising a plurality of tracks on which said load handling devices may move on a grid structure, said plurality of tracks being arranged in a grid pattern and defining a grid structure lying in a horizontal plane, each of said plurality of tracks being subdivided into a plurality of elongated track elements; 1. A track system wherein each of the plurality of elongated track elements is formed from a sheet metal blank having at least two bend lines to form a substantially U-shaped cross-section having upper and lower flanges and a vertical element extending between the upper and lower flanges, wherein one or more of the plurality of tracks is integral with the upper flange.

[0145] Clause 2. A track system for a storage and retrieval system comprising one or more load handling devices operable on the track system, said track system comprising a plurality of tracks arranged in a grid pattern comprising a plurality of grid cells in which said load handling devices can move on the grid structure, said plurality of tracks arranged in the grid pattern to define a grid structure lying in a horizontal plane, each of said plurality of tracks being subdivided into a plurality of elongated track elements; wherein the track system further comprises a track support structure comprising a plurality of track supports arranged in a grid pattern corresponding to the grid pattern of the track system, wherein each of the plurality of track supports is formed from a sheet metal blank having at least two bend lines to form a substantially U-shaped cross-section having upper and lower flanges and a vertical element extending between the upper and lower flanges, and wherein one or more of the plurality of tracks are mounted on the track support structure.

[0146] Clause 3. The track system of any preceding clause, wherein the U-shaped cross section is formed by cold rolling.

[0147] Clause 4. The track system of any preceding clause, wherein the sheet metal blank comprises steel.

[0148] Clause 5. A track system as described in any one of clauses 2 to 4, wherein the track is attached to the upper flange by fasteners.

[0149] Clause 6. The track system of clause 5, wherein the fastener comprises one or more U-shaped brackets configured to clamp the upper flange to the track.

[0150] Clause 7. A system as described in any one of clauses 2 to 6, wherein the track comprises a recess for receiving the track support.

[0151] Clause 8. A track system as described in any one of clauses 2 to 7, wherein the track is configured to be snap-fit ​​onto the track support.

[0152] Clause 9. The track system of any one of clauses 2 to 8, wherein the track comprises plastic.

[0153] Clause 10. The track system of any preceding clause, wherein the track comprises steel.

[0154] Clause 11. The track system of any preceding clause, wherein the track comprises a raised central region extending along the longitudinal length of the track.

[0155] Clause 12. A track system as described in clause 11, wherein the track comprises a pair of recesses extending side by side along the longitudinal length of the track, wherein the pair of recesses define a path for the one or more load handling devices.

[0156] Clause 13. A track system according to any preceding clause, wherein the plurality of tracks are subdivided into a plurality of track sections, each track section comprising a first track section element extending in a first direction and a second track section element extending in a second direction.

[0157] Clause 14. A track system as described in clause 13, wherein each track section is formed as a single integral body.

[0158] Article 15. A grid framework structure for a storage and retrieval system, comprising: a track system according to any of the preceding clauses; a support framework structure that supports the track system; and a plurality of stacks of containers disposed within storage columns located below the track system.

[0159] Clause 16. A storage and retrieval system comprising the grid framework of clause 15 and one or more load handling devices for lifting and moving containers stacked in a stack, each load handling device comprising: a wheel assembly for moving the load handling device on the track; a container receiving space positioned above the track system; a lifting device arranged to lift a single container from said stack into said container receiving space.

Claims

1. 1. A track system for a storage and retrieval system comprising one or more load handling devices operable on the track system, a. a plurality of tracks arranged in a grid pattern for guiding one or more load handling devices operable on said track system; b. a plurality of track supports arranged in a grid pattern, the first set of track supports extending in a first direction and the second set of track supports extending in a second direction, the second direction being substantially perpendicular to the first direction such that the first set of track supports intersect the second set of track supports at one or more nodes in the track system, each of the plurality of track supports being formed from a sheet metal blank folded along a plurality of bend lines; wherein the first set of track supports intersect with the second set of track supports by the second set of track supports being received within one or more notches in the first set of track supports at the one or more nodes in the track system.

2. The track system of claim 1 , wherein at least a portion of the cross-sectional profile of the notch in the first set of track supports corresponds to at least a portion of the cross-sectional profile of the second set of track supports.

3. 3. The track system of claim 1, wherein each of the plurality of track supports has a substantially rectangular cross section.

4. 4. The track system of claim 1, wherein at least one free end of the folded sheet metal blank along the longitudinal length of the track support is bent inwardly to form at least one track support surface for mounting a track.

5. 5. The track system of claim 4, wherein at least one free end of the folded sheet metal blank comprises a pair of opposing free ends for providing a pair of opposing track support surfaces for mounting tracks.

6. The track system of claim 5 , wherein the pair of opposing free ends are spaced apart to provide a channel extending along the longitudinal length of the track support.

7. 7. The track system of claim 1, wherein the one or more cutouts in the first set of track supports have a profile that corresponds to a cross-sectional profile of the second set of track supports.

8. The track system of claim 1 or 2, wherein each of the track supports comprises an H-shaped cross-sectional profile.

9. The track system of claim 8 , wherein the cross-sectional profile of the first set of track supports is the same as the cross-sectional profile of the second set of track supports.

10. 10. The track system of claim 8 or 9, wherein each of the track supports comprises a track connecting portion for connecting to the track, and wherein the track supports of a second set comprise one or more notches, and wherein each intersection of the track system is formed by assembling tracks of the second set with track supports of a first set in a substantially vertical direction such that their respective track connecting portions are coplanar.

11. 11. A track system according to any one of claims 8 to 10, wherein the one or more cutouts each have a height corresponding to approximately half the height of the track support.

12. The track system of claim 11 , wherein the first set of track supports are rotated about their longitudinal axes so that the one or more notches face upward.

13. 13. The track system of claim 1, wherein each of the plurality of track supports includes a plurality of slots spaced apart in a direction along a longitudinal length of the track support, and each of the plurality of tracks includes a plurality of tabs for engaging the plurality of slots of the track support to prevent the plurality of tracks from disengaging from the plurality of track supports.

14. 14. The track system of claim 13, wherein each of the slots is sized to allow at least a portion of each of the plurality of tracks to move in a direction along the longitudinal length of the respective track support.

15. 15. A track system according to claim 13 or 14, wherein the track is oriented so that the length of each slot extends in a direction along the longitudinal length of the track support.

16. The track system of claim 1 , wherein each of the plurality of tracks is configured to snap-fit ​​onto a respective one of the plurality of track supports.

17. 17. The track system of claim 13, wherein the plurality of tracks are subdivided into a plurality of track sections, each track section comprising a first track section element extending in the first direction and a second track section element extending in the second direction, the first track section element being movable relative to the second track section element on the track support when mounted in a plurality of slots.

18. 20. The track system of claim 17, wherein each track section is formed as a single, integral body.

19. 19. The track system of any one of claims 1 to 18, wherein the plurality of tracks comprises plastic.

20. 19. The track system of claim 1, wherein the plurality of tracks comprises metal.

21. 1. A grid framework structure for a storage and retrieval system, comprising: A track system according to any one of claims 1 to 20; a support framework structure that supports the track system; and a plurality of stacks of containers disposed within storage columns located below the track system.

22. 22. The grid framework structure of claim 21, wherein the track system further comprises one or more anti-crush devices, wherein the one or more anti-crush devices are interposed between the support framework structure and the track supports.

23. 23. The grid framework structure of claim 22, wherein the one or more anti-crush devices are attachable to the underlying support framework structure and the track supports.

24. 24. A grid framework structure according to claim 22 or 23, wherein the one or more anti-crush devices extend in the same direction as the track supports above the one or more anti-crush devices.

25. 25. A grid framework structure according to any one of claims 22 to 24, wherein the one or more anti-crush devices each comprise at least one raised positioning feature, and the plurality of track supports and the underlying supporting framework structure each comprise one or more holes for accommodating the at least one raised positioning feature of the one or more anti-crush devices.

26. 26. The grid framework structure of claim 25, wherein the at least one raised positioning feature comprises a pair of raised positioning features on a top surface of the crush-resistant device and a pair of raised positioning features on a bottom surface of the crush-resistant device.

27. 27. The grid framework structure of any one of claims 22 to 26, wherein each of the one or more anti-crush devices comprises cast steel.

28. 28. A grid framework structure according to any one of claims 22 to 27, wherein the one or more anti-crush devices comprise a plurality of anti-crush devices.

29. 30. The grid framework structure of claim 28, wherein the plurality of anti-crush devices are spatially distributed in a direction along the length of the track system and / or the supporting framework structure.

30. 30. A grid framework structure according to any one of claims 22 to 29, wherein the one or more anti-crush devices are positioned between nodes in the track system.

31. 31. A storage and retrieval system comprising a grid framework structure according to any one of claims 21 to 30 and one or more load handling devices for lifting and moving containers stacked in a stack, each load handling device comprising: a wheel assembly for moving the load handling device on a track system; a container receiving space positioned above the track system; A storage and retrieval system comprising a lifting device arranged to lift a single container from the stack into said container receiving space.

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