Device for retrieving storage container from storage and retrieval system

Abstract

To provide a load handling device that is easy to assemble, is lightweight, and lower cost to manufacture.SOLUTION: A plurality of modular sections 132a, 134a, 136a, 138a includes a container lifting mechanism, a wheel assembly, a wheel positioning mechanism, and electrical components. Each of at least four connection blocks 140 is connected to two other connection blocks 140 in a single modular section by one or more substantially horizontal connection elements 184 to form a rectangular frame 186. The at least four connection blocks 140 of vertically adjacent modular sections are connectable in a vertical stack by one or more substantially vertical connection elements 188 to form an open frame structure including a plurality of rectangular frames. The open frame structure is configured to support the container lifting mechanism, the wheel assembly, the wheel positioning mechanism, and the electrical components.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to an apparatus for retrieving storage containers from a storage and retrieval system. In particular, but not exclusively, the present invention relates to a robotic load handling apparatus for handling storage containers in a storage and retrieval system comprising a grid framework structure. [Background technology]

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

[0003] As shown in FIGS. 1 and 2, stackable containers known as storage receptacles or containers 10 are stacked on top of each other to form stacks 12. The stacks 12 are arranged in a three-dimensional grid framework structure 14 in a warehousing 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. FIG. 1 is a schematic perspective view of the grid framework structure 14, and FIG. 2 is a top view showing the stack 12 of receptacles 10 arranged within the framework structure 14. Each receptacle 10 typically holds multiple product items (not shown), which may be of different product types or may be the same, depending on the application. The receptacles 10 may also be referred to as storage receptacles or containers, or storage bins or totes.

[0004] Specifically, the three-dimensional grid framework structure 14 comprises a plurality of vertical uprights or upright members or columns 16 that support horizontal grid members 18, 20. A first set of parallel horizontal grid members 18 are disposed perpendicularly to a second set of parallel horizontal grid members 20 to form a grid structure or grid 15 comprising a plurality of grid cells 17. The grid cells have openings to allow load handling equipment to lift containers or storage receptacles through the grid cells. In the grid structure, the first set of parallel horizontal grid members 18 intersect with the second set of parallel horizontal grid members at nodes. The grid structure is supported by upright members 16 at each of the nodes or points where the grid members intersect, such that the upright members are interconnected at their upper ends by the intersecting grid members. The grid members 16, 18, 20 are typically fabricated from metal and are typically welded or bolted together, or a combination of both. The storage receptacles or containers 10 are stacked between upright members 16 of a grid framework structure 14 such that the upright members 16 prevent horizontal movement of the stack 12 of receptacles 10 and guide vertical movement of the storage receptacles 10 .

[0005] The top level of the grid framework structure 14 includes rails 22 arranged in a grid pattern across the top of the stacks 12. Referring still to FIG. 3 , the rails 22 support a plurality of load handling apparatuses 30. A first set 22a of parallel rails 22 guides movement of the robotic load handling apparatus 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 arranged perpendicular to the first set 22a guides movement of the load handling apparatus 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 apparatus 30 laterally in two dimensions in the horizontal XY plane, such that the load handling apparatus 30 can be moved to a position above any stack 12.

[0006] A known load handling apparatus or robotic load handling apparatus, also known as a bot 30, shown in Figures 4 and 5, is described in PCT Patent Publication No. WO2015 / 019055 (Ocado), which is incorporated herein by reference, comprising a vehicle body 32, where each load handling apparatus 30 covers only a single grid space or grid cell of a grid framework structure 14. Here, the load handling apparatus 30 comprises a wheel assembly comprising a first set of wheels 34 consisting of a pair of wheels at the front of the vehicle body 32 and a pair of wheels 34 at the rear of the vehicle 32 for engaging a first set of rails or tracks to guide movement of the apparatus in a first direction, and a second set of wheels 36 consisting of a pair of wheels 36 on either side of the vehicle 32 for engaging a second set of rails or tracks to guide movement of the apparatus in a second direction. Each of the sets of wheels is driven to enable movement of the vehicle in the X and Y directions, respectively, along the rails. One or both sets of wheels may 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 structure, e.g., in the X or Y direction.

[0007] WO2017 / 153583 (Ocado Innovation Limited) teaches a load handling apparatus comprising a wheel positioning or steering mechanism for enabling either a first set of wheels or a second set of wheels to selectively engage with a first or second set of rails or tracks (22a or 22b), thereby enabling lateral movement of the apparatus in one of two transverse directions. The wheel positioning mechanism comprises a complex arrangement of linkages driven by linear actuators or motors for selectively lowering or raising the first set of wheels or the second set of wheels to engage or disengage with the first set of tracks or rails or the second set of tracks or rails.

[0008] The load handling apparatus 30 is equipped with a lifting mechanism, or container lifting mechanism, or crane mechanism, for lifting storage containers 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 in the form of a lifting frame. The lifting device includes a set of lifting tethers 38 (one tether near each of the four corners of the grabber device) extending vertically and connected near or at the four corners of the lifting frame 39, also known as grabber devices, for releasable connection to the storage container 10. The grabber device 39 is configured to releasably grip 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.

[0009] The wheels 34, 36 are arranged around the periphery of a cavity or recess known as a container-receiving recess 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 receptacle 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 disposed within the vehicle body, as described, for example, in WO 2015 / 019055 (Ocado Innovation Limited). Alternatively, the vehicle 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 hoisted by the cantilever, which enables the grabber device to engage a container and lift it from the stack into the container-receiving space below the cantilever.

[0010] Typically, the load handling apparatus includes one or more electrical components, such as a rechargeable power supply and a control unit for powering drive units for operating the lifting mechanism and wheel positioning mechanism. For example, one or more remotely operable load handling apparatuses on a grid structure are configured to receive commands from a master controller to retrieve a storage container from a specific storage location within the grid framework structure. Wireless communications and networks may be used to provide a communications infrastructure from the master controller through one or more base stations to one or more load handling apparatuses operable on the grid structure. In response to receiving the commands, the controller in the load handling apparatus is configured to control various drive mechanisms to control movement of the load handling apparatus. For example, the load handling apparatus may be instructed to retrieve a container from a storage column at a specific location on the grid structure. The commands may include various movements in the X and Y directions on the grid structure. Upon reaching the storage column, the lifting mechanism is then operated to grasp the storage container and lift it into a container-receiving space in the main body of the load handling apparatus, where it is then transported to another location on the grid structure, commonly known as a drop-off port. The containers are lowered to suitable picking stations to allow removal of items from the storage containers. Movement of the load handling equipment on the grid structure also involves commanding the load handling equipment to move to charging stations, which are typically located on the periphery of the grid structure. Electrical components of the load handling equipment are typically housed within the body of the load handling equipment.

[0011] Considering the number of components, including various motors, pulleys, and electrical components such as batteries and control boards, required for a load handling device to operate on a grid framework structure, assembling the individual components together is one of the largest costs in manufacturing a load handling device. Considering that there are hundreds of load handling devices that can operate on a grid framework structure, the cumulative cost of multiple load handling devices that can operate on the grid structure represents a significant portion of the cost of a typical storage and retrieval system. Not only does the cost of manufacturing the load handling devices represent a significant portion of the cost of the storage and retrieval system, but the weight of the load handling devices, which can exceed 150 kg, can also lead to other additional costs. For example, due to the weight of the load handling devices, the grid framework structure must have sufficient structural integrity to support the weight of multiple load handling devices that can operate on the grid framework structure. Various bracing elements are used to increase the strength of the grid framework structure, which ultimately increases the cost of the grid framework structure and, therefore, the overall cost of the storage and retrieval system. As the weight of the load handling equipment increases, more power is also required to drive the wheel motors to move the load handling equipment on the track at sufficient speed, which in turn translates into larger and more powerful electric motors and larger batteries to provide the power necessary to drive the electric motors.

[0012] Therefore, there is a need for a load handling device that is easier to assemble, lighter in weight, and less expensive to manufacture. Summary of the Invention

[0013] The present invention alleviates the above problems by providing a load handling apparatus or robotic load handling apparatus comprising a plurality of modules connectable to one another in a vertical stack, where each module provides a respective functional characteristic of the load handling apparatus, such as a wheel assembly, a wheel positioning mechanism, a container lifting mechanism, and electrical components. The individual modules are connectable, allowing modules providing different functions of the load handling apparatus to be vertically stacked. To connect the individual modules together, the individual modules comprise a plurality of connection blocks providing connection points for stacking the modules. More specifically, the present invention provides a load handling apparatus for lifting and moving one or more stackable containers in a storage and retrieval system, the storage and retrieval system comprising a grid structure comprising a plurality of grid members, the grid members comprising a first set of grid members and a second set of grid members, the second set of grid members being substantially perpendicular to the first set of grid members, whereby the plurality of grid members are arranged in a grid pattern for guiding movement of the load handling apparatus over the grid structure; the load handling apparatus comprising a plurality of modular sections arranged in a vertical stack, the plurality of modular sections a) a container lifting mechanism comprising a container gripper assembly configured to releasably grip a container, and a drive mechanism configured to raise and lower the container gripper assembly; b) a wheel assembly comprising a first set of wheels for engaging a first set of grid members to guide movement of the load handling apparatus in a first direction and a second set of wheels for engaging a second set of grid members to guide movement of the load handling apparatus in a second direction, wherein the second direction is transverse to the first direction; c) a wheel positioning mechanism configured to selectively lower or raise the first set of wheels or the second set of wheels to engage or disengage with the first set of grid members or the second set of grid members; Equipped with wherein each of the plurality of modular sections further comprises at least four connection blocks, each of the four connection blocks being connected to two other connection blocks in a single modular section by one or more horizontal connection elements to form a rectangular frame, and wherein at least four connection blocks of vertically adjacent modular sections are connectable in a vertical stack by one or more vertical connection elements to form an open frame structure comprising a plurality of rectangular frames, the open frame structure being configured to support a container lifting mechanism, a wheel assembly, and a wheel positioning mechanism.

[0014] For purposes of the present invention, each of the first and second sets of grid members may optionally include track supports having attached thereto a track system comprising a first set of tracks attached to the first set of grid members and a second set of tracks attached to the second set of grid members. The track system may be a separate component from the grid members, or alternatively, the track system may be integrally integrated into, i.e., form part of, the grid members. The load handling apparatus is operable to move along the grid tracks.

[0015] Optionally, the load handling apparatus comprises one or more electrical components, for example the one or more electrical components comprising a processor and / or power source for controlling the container lifting mechanism and the wheel positioning mechanism.

[0016] Preferably, the open frame structure is a three-dimensional open frame structure defining a volume for accommodating at least a portion of the lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or the electrical components. For purposes of the present invention, the term "open frame structure" is defined as a structure in which the internal operating components of the load handling apparatus, such as any one of the spools for carrying the lifting tethers of the container lifting mechanism, and / or the power supply and / or the control unit, are visible from the exterior of the load handling apparatus. Preferably, the open frame structure defines a plurality of modular sections, each comprising the lifting mechanism, the wheel assembly, the wheel positioning mechanism, and the electrical components. The term open frame structure is interpreted as covering the load handling apparatus without external cladding, whereby the internal components providing the functional features of the load handling apparatus are visible from the exterior.

[0017] Preferably, the vertically adjacent rectangular frames of the open frame structure define a volumetric area of ​​the load handling apparatus, for example the open frame structure is a three dimensional open frame structure.

[0018] The at least four connecting blocks not only allow different modular sections to be easily connectable in a vertical stack, but each of the at least four connecting blocks can also be connected to two other connecting blocks in a single modular section by one or more horizontal connecting elements to form a rectangular frame. The connection between a connecting block to two other corner connecting blocks in a single modular frame can be made directly to two adjacent connecting blocks or indirectly through another connecting block.

[0019] Thus, multiple rectangular frames can be connected to one another in a vertical stack by one or more vertical connecting elements to form an open frame structure. Different functions of the load handling apparatus, such as container lifting mechanisms, wheel assemblies, wheel positioning mechanisms, and / or electrical components, are supported by the open frame structure. The term "supported" is interpreted broadly to include being physically supported by and / or forming part of the open frame structure.

[0020] To facilitate assembly of the open frame structure, optionally, one or more of the horizontal and / or vertical connecting elements comprise connecting rods or tubes. The connecting rods can be easily grasped and assembled to the blocks in different rotational orientations. Thus, assembly of the load handling equipment is easier with the connecting blocks and connecting rods. To help reduce the weight of the load handling equipment, optionally, the connecting rods comprise carbon fiber in a polymer matrix. To increase the structural integrity of the open frame structure, optionally, the rectangular frames in one or more of the plurality of modular story sections are braced by one or more bracing elements extending between one or more of the opposing horizontal connecting elements. Preferably, the one or more bracing elements comprise crossed bracing elements. In addition to the horizontal and vertical connecting elements that provide structural support to the open frame structure, one or more bracing elements extend across the horizontal and / or vertical connecting elements. The one or more bracing elements may also provide additional support for securing one or more components of the lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or the electrical component.

[0021] Optionally, the at least four connecting blocks comprise four corner brackets such that each corner bracket of the four corner brackets is connected to two other corner brackets in the single modular frame to form a rectangular frame.

[0022] To increase the ease with which rectangular frames can be connected together in a vertical stack, optionally, one or more vertical connection elements extend vertically through one or more of the at least four connection blocks of vertically adjacent rectangular frames in the vertical stack. In other words, the vertical element is common to one or more connection blocks of vertically adjacent rectangular frames. This allows for the construction of an open-frame structure by individually attaching rectangular frames to one or more vertical connection elements. The number of modular sections, and therefore the functional requirements of the load handling device, can be tailored by increasing the number of rectangular frames attached to one or more vertical connection elements.

[0023] Preferably, one or more of the at least four connection blocks of one or more of the plurality of modular sections are connected to one or more horizontal and / or vertical connection elements by joints. The connection between the horizontal connection element and the bracket by the joint optionally comprises a continuous glue channel. To increase the functionality of one or more of the four corner blocks, the continuous glue channel is integrated into one or more of the at least four connection blocks. Preferably, one or more of the at least four connection blocks comprises one or more injection points in fluid communication with the continuous glue channel for injecting adhesive into the continuous glue channel. Optionally, one or more of the connection blocks comprises a socket for receiving an end of a connecting rod or tube. Preferably, the socket is integrally formed within the connection block. To secure the connecting rod or tube to the connection block, the socket preferably has a substantially cylindrical inner wall with a groove extending continuously around at least a portion of the cylindrical inner wall for distributing adhesive axially along the receiving end of the rod, the groove configured to form a glue channel when the receiving end of the connecting rod is inserted into the socket. Preferably, one or more of the at least four connection blocks include one or more injection points in fluid communication with the groove for injecting adhesive into the glue channel. This helps simplify connecting one or more blocks of one or more of the multiple modular sections with horizontal and / or vertical connection elements.

[0024] Preferably, the open frame structure defines a volume for accommodating a container-receiving space such that the footprint of the load handling apparatus substantially occupies the footprint of only a single grid space or cell. The container-receiving space is a space for accommodating a container in the open frame structure of the load handling apparatus such that the load handling apparatus can move on the track or grid structure. The three-dimensional open frame structure defines a volume having an upper portion and a lower portion, the upper portion accommodating auxiliary components of the load handling apparatus, i.e., a power supply, a control unit, and a wheel positioning mechanism, and the lower portion accommodating the container-receiving space.

[0025] One of the advantages of a load handling apparatus constructed from multiple connection blocks connected together to form multiple rectangular frames and stacked vertically to form an open-frame structure is that the connection blocks provide not only structural components but also functional components for the load handling apparatus. In other words, each of the at least four connection blocks in each of the multiple modular sections is a separate connection block that provides both structural and functional components for the load handling apparatus. Because one or more of the connection blocks can combine both structural and functional aspects of the load handling apparatus, this eliminates the need for separate structural components that provide the structural integrity of the load handling apparatus and separate functional components for operation of the load handling apparatus on a grid structure. Having one or more of the connection blocks of an open-frame structure include both structural and functional components for the load handling apparatus also reduces the weight of the load handling apparatus because the number of parts required to build the load handling apparatus of the present invention is reduced.

[0026] In aspects of the invention, one or more of the at least four connection blocks in one or more of the modular sections provide at least a portion of the functionality of the load handling apparatus, the functionality being any one of a container lifting mechanism, a wheel assembly, a wheel positioning mechanism, and / or an electrical component. Optionally, one or more of the at least four connection blocks in one or more of the plurality of modular sections comprises one or more mounts for a pulley. Optionally, one or more of the at least four connection blocks in one or more of the plurality of modular sections comprises one or more mounts for a motor.

[0027] Optionally, at least a portion of the lifting mechanism, and / or wheel assembly, and / or wheel positioning mechanism, and / or electrical components are integrally formed from one or more of the at least four connecting blocks of one or more of the plurality of modular sections comprising at least a portion of the lifting mechanism, and / or wheel assembly, and / or wheel positioning mechanism, and / or electrical components.

[0028] At least a portion of one or more of the connecting blocks of one or more of the plurality of modular sections, i.e., the open frame structure, is integrally formed with at least a portion of the lifting mechanism, wheel assembly, wheel positioning mechanism, and / or electrical components. For example, a mount for attaching each of the wheels of the wheel assembly may be integrally formed with one or more of the at least four connecting blocks.

[0029] Preferably, each wheel of the wheel assembly is mounted to a wheel mount. Optionally, the wheel mount is integrally formed from the connecting block of the given modular section. In an aspect of the invention, the connecting block of the given modular section comprises a first wheel mount for a wheel of the first set of wheels and a second wheel mount for a wheel of the second set of wheels, the first wheel mount and the second wheel mount comprising a plurality of bosses along their edges, each of the plurality of bosses of the first wheel mount and the second wheel mount comprising an opening axially aligned along a wheel positioning axis (the wheel positioning axis being a substantially vertical axis), the plurality of bosses of the first wheel mount and the second wheel mount being spaced apart such that the plurality of bosses of the first wheel mount and the second wheel mount interdigitate with each other, and the opening in each of the interdigitated bosses of the first wheel mount and the second wheel mount being axially aligned along the wheel positioning axis for receiving a vertical connecting element therethrough. The spacing between the bosses of the first wheel mount and the second wheel mount is sufficiently spaced to allow the first wheel mount to move independently of the second wheel mount along a wheel positioning axis. Wheel mounts having first wheel mounts for wheels of a first set of wheels and second wheel mounts for wheels of a second set of wheels allow the wheels mounted on their respective first and second wheel mounts to move independently along a vertical axis relative to each other to engage and disengage from the grid structure. The wheel mounts operate in conjunction with the wheel positioning mechanism to redirect the load handling device on the grid structure.

[0030] Optionally, the wheel positioning mechanism comprises a cam mechanism, and one or more of the at least four connecting blocks comprises at least a portion of the cam mechanism. Optionally, at least a portion of the cam mechanism is integral with one or more of the at least four connecting blocks.

[0031] In a further aspect of the invention, the open frame structure provides physical support for at least a portion of any one of the container lifting mechanism, wheel assembly, wheel positioning mechanism, and / or electrical components. For example, horizontal connecting elements extending between opposing connecting blocks may be used to physically mount one or more functional components of the load handling apparatus. Optionally, the container lifting mechanism includes: a) a first set of spools and a second set of spools, wherein each spool of the first set of spools and the second set of spools carries a lifting tether having a first end secured to the container gripping assembly and a second end secured to the spool; b) a rotatable shaft, wherein the first set of spools and / or the second set of spools are mounted on the rotatable shaft such that the rotatable shaft is common to the first set of spools and / or the second set of spools; c) a drive mechanism comprising a drive pulley attached to a rotatable shaft common to the first set of spools and / or the second set of spools such that rotation of the rotatable shaft by the drive pulley drives rotation of the first set of spools and / or the second set of spools; Equipped with.

[0032] Preferably, the rotatable shaft is attached to one or more horizontal connecting elements connecting two adjacent connecting blocks. Preferably, the rotatable shaft extends between opposing horizontal connecting elements connected to the connecting blocks.

[0033] Optionally, any one of the lifting mechanism, wheel assembly, wheel positioning mechanism, and / or electrical component may be shared among two or more of the plurality of modular sections. For example, the wheel positioning mechanism comprises a cam mechanism including a cam having a cam profile with hills and valleys, a cam follower, and a traveler for moving the cam follower along the cam profile to convert movement of the cam along the cam profile into vertical movement. Cooperation between the cam, cam follower, and traveler may be shared among two or more of the plurality of modular sections. Optionally, a plurality of vertically adjacent rectangular frames define a volume for accommodating at least a portion of the container lifting mechanism, wheel assembly, wheel positioning mechanism, and / or electrical component. Optionally, one or more of the at least four connection blocks of one or more of the plurality of rectangular frames of the open frame structure are 3D printed. Optionally, the at least four connection blocks of each of the plurality of rectangular frames are 3D printed (e.g., formed by additive manufacturing).

[0034] The number of modular sections in the vertical stack can be determined depending on the function of the load handling apparatus. By including modular sections, the functional characteristics of the load handling apparatus can be changed by changing the number of modular sections in the stack. In one embodiment of the present invention, the plurality of modular tier sections in ascending height order of the load handling apparatus include first, second, third, and fourth modular tier sections, with the first modular tier section being at the bottom of the load handling apparatus and the fourth modular tier section being at the top of the load handling apparatus. To allow the load handling apparatus to move on the grid structure, the first modular section preferably includes wheel assemblies. To allow the open-frame structure of the load handling apparatus to provide a container-receiving space, the fourth modular section preferably includes one or more cradles for supporting electrical components. Optionally, the one or more cradles are attached to one or more of the horizontal connection elements connecting two adjacent connection blocks of the fourth modular section.

[0035] A further aspect of the present invention provides a method of constructing load handling apparatus, the method comprising: i) forming a rectangular frame by connecting at least four connecting blocks together by one or more horizontal connecting elements; ii) linking a plurality of rectangular frames together in a vertical stack by connecting the connection blocks of vertically adjacent rectangular frames by one or more vertical connection elements to form an open frame structure; The open frame structure is a) a container lifting mechanism comprising: a) a grabber device configured to releasably grasp a container; and a drive mechanism configured to raise and lower the grabber device; b) a wheel assembly arranged to support a vehicle body, wherein the wheel assembly comprises a first set of wheels for engaging a first set of grid members to guide movement of the load handling apparatus in a first direction, and a second set of wheels for engaging a second set of grid members to guide movement of the load handling apparatus in a second direction, the second direction being transverse to the first direction, and each wheel of the first set of wheels and the second set of wheels being attached to a wheel mount; c) a wheel positioning mechanism configured to selectively lower or raise the first set of wheels or the second set of wheels to engage or disengage with the first set of tracks or rails or the second set of tracks or rails; Support.

[0036] Optionally, the open frame structure further supports one or more electrical components, the one or more electrical components comprising a processor and / or power source for controlling the container lifting mechanism and the wheel positioning mechanism.

[0037] Optionally, the open frame structure is formed by inserting one or more of the plurality of horizontal and / or vertical connecting elements into openings in one or more of the at least four connecting blocks. Optionally, the method further comprises attaching a lifting mechanism, and / or a wheel assembly, and / or a wheel positioning mechanism, and / or at least a portion of the electrical components to the open frame structure.

[0038] To reduce the weight of the load handling apparatus according to the present invention and thus facilitate its construction, the method further comprises integrally forming at least a portion of the container lifting mechanism, the wheel assembly, and / or the wheel positioning mechanism from one or more of the at least four connection blocks of the open frame structure. By integrally forming at least a portion of the functional components of the load handling apparatus from the open frame structure, and more particularly from one or more of the connection blocks of the open frame structure, the number of components required to build a load handling apparatus having the desired functional characteristics of a load handling apparatus operable on a grid framework structure is reduced. To capture different complex shapes of at least a portion of the container lifting mechanism, the wheel assembly, and the wheel positioning mechanism, optionally one or more of the at least four connection blocks of one or more of the plurality of rectangular frames are formed by 3D printing or additive manufacturing.

[0039] Further features and aspects of the present invention will become apparent from the following detailed description of illustrative embodiments that proceeds with reference to the drawings. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 1 is a schematic diagram of a grid framework structure according to a known system. [Figure 2] FIG. 2 is a schematic diagram of a top view showing a stack of containers arranged within the framework structure of FIG. [Figure 3] FIG. 3 is a schematic diagram of a known storage system for load handling equipment operating on a grid framework structure. [Figure 4] FIG. 4 is a schematic perspective view of the load handling apparatus showing a lifting device gripping a container from above. [Figure 5] 5(a) and 5(b) are schematic perspective cutaway views of the load handling apparatus of FIG. 4, showing (a) a container accommodated within the container receiving space of the load handling apparatus, and (b) the container receiving space of the load handling apparatus. [Figure 6] FIG. 6 is a schematic diagram of a load handling apparatus according to one embodiment of the present invention. [Figure 7] FIG. 7 is a perspective view of a grabber device for engaging a storage container in accordance with the present invention. [Figure 8] 8(a) and 8(b) are schematic diagrams of (a) the different modular sections of the load handling apparatus shown in FIG. 6 and (b) an analogy of the different modular sections as separate rectangular frames formed by four connecting blocks. [Figure 9] 9(a) and 9(b) are schematic diagrams of simplified versions of (a) the assembly of modular sections shown in FIG. 8(a) to form an open frame structure of a load handling apparatus, and (b) the assembly of a rectangular frame of modular sections shown in FIG. 8(b) to form an open frame structure of a load handling apparatus. [Figure 10] FIG. 10 is a schematic diagram showing the assembly of a connecting block with a wheel mount of a wheel assembly. [Figure 11] Figure 11 is a schematic diagram showing the assembly of connecting blocks to form a rectangular frame, which is braced to represent the intermediate halo of an open frame structure. [Figure 12] FIG. 12 is a schematic diagram showing the assembly of connecting blocks to form the top rectangular frame of the fourth modular section of the open frame structure shown in FIG. 8(a). [Figure 13] FIG. 13 is a schematic diagram of the connecting blocks that form the corner brackets of the top or fourth modular section. [Figure 14] FIG. 14 is a schematic diagram of the connecting blocks forming the corner brackets of the third modular section. [Figure 15] FIG. 15 is a schematic diagram of the connecting blocks forming the corner brackets of the second modular section. [Figure 16]FIG. 16 is a schematic diagram of the connecting blocks forming the corner brackets of the first or bottom modular section that includes the wheel mounts. [Figure 17] FIG. 17 is a schematic illustration of glue channels in a connecting block for fastening to connecting elements according to a first example of the present invention. [Figure 18] Figures 18(a and b) are schematic diagrams of glue channels in a connecting block for fastening to a connecting element according to a second example of the present invention, where (a) is a side perspective view of the glue channel and (b) is a top view of the glue channel. [Figure 19] FIG. 19 is a cross-sectional view showing a joint between a connecting block and a connecting element with external and internal glue channels according to a third example of the invention. [Figure 20a] FIG. 20a is a schematic diagram of an example of a glue channel for forming the joint shown in FIG. [Figure 20b] FIG. 20b is a schematic diagram of an example of a glue channel for forming the joint shown in FIG. [Figure 21a] FIG. 21a is a schematic diagram of another example of glue channels forming the joint shown in FIG. [Figure 21b] FIG. 21b is a schematic diagram of another example of glue channels forming the joint shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention addresses known features of storage systems, such as the grid framework structure and load handling apparatus described above with reference to FIGS. 1-5. FIG. 6 is a schematic diagram of an example of a load handling apparatus 130 according to the present invention. Typical load handling apparatuses in the art include a separate rigid framework or chassis, and the functional components of the load handling apparatus, such as the lifting mechanism, wheel positioning mechanism, wheel assemblies, wheel drive assemblies, and electrical components, e.g., a rechargeable power supply and / or control unit, are literally secured or attached to the framework. The securing includes various fasteners, such as bolts, screws, and / or welding. The framework is typically in the form of a tower with a height representing the height of the load handling apparatus. To ensure the structural integrity of the rigid framework, which supports the weight of the various functional components of the load handling apparatus, the rigid framework is generally constructed from metal, e.g., aluminum or stainless steel. Cladding is secured to the outside of the framework to form a vehicle body that houses the functional features of the load handling apparatus. The accumulation of weight between the rigid framework and the various functional parts of the load handling device results in a load handling device with a weight exceeding 150 kg. Compared to load handling devices in the art, the present load handling device does not have any cladding and has a mostly open frame structure.

[0042] According to one embodiment of the present invention, the construction of a cargo handling apparatus 130 according to the present invention, as shown in FIG. 6, revolves around the principle of having a modular system comprising a plurality of modules or modular sections connectable in a vertical stack to provide different functional features of the cargo handling apparatus. In a further aspect of the present invention, the modular system is integrated into an open frame structure or framework 131 such that the open frame structure comprises a plurality of modular frames connectable to one another in a vertical stack to provide different functional features of the cargo handling apparatus. The terms "open frame structure" and "frame" are used interchangeably in this patent specification to refer to the same feature. In yet a further aspect of the present invention, at least a portion of the functional components of the cargo handling apparatus are integrally formed within the open frame structure of the cargo handling apparatus. An example of a cargo handling apparatus 130 incorporating the inventive concepts of the present invention is shown in FIG. 6, and different modular sections providing different functional features of the cargo handling apparatus are shown in FIGS. 8(a) and 8(b). The different modular sections 132(a and b), 134(a and b), 136(a and b), 138(a and b) are labeled first, second, third, and fourth modular sections, respectively, in Figures 8(a and b). As can be seen from the exploded views of the load handling apparatus shown in Figures 8(a and b), the different modular sections of the load handling apparatus include connection points 140 at the corners of the modules 132(a and b), 134(a and b), 136(a and b), 138(a and b) to allow the different modular sections to be stacked vertically.

[0043] In the specific embodiment of the invention shown in Figures 8(a and b), four modular sections 132(a and b), 134(a and b), 136(a and b), and 138(a and b) are shown connectable in a vertical stack to form a tier-based modular system. Starting with the bottom modular section 132(a and b), and increasing in height of the load handling apparatus, the four modular sections are labeled, for purposes of explanation of the invention, as first modular section 132(a and b), second modular section 134(a and b), third modular section 136(a and b), and fourth modular section 138(a and b). The four modular sections provide different functional features of the load handling apparatus. In certain embodiments of the present invention, different functional features of the load handling apparatus may be shared between one or more of the modular sections 132(a and b), 134(a and b), 136(a and b), 138(a and b) of the load handling apparatus 130. For example, a wheel positioning mechanism and a wheel drive assembly may be shared between two or more modular sections of the load handling apparatus. The number of modular sections is not limited to four modular sections, and different functional features of the load handling apparatus may be divided among any number of modular sections.

[0044] The different functional features of the load handling apparatus include, but are not limited to, wheel assemblies for enabling movement of the load handling apparatus on a grid structure or track, wheel drive assemblies for driving the wheel assemblies to enable movement of the load handling apparatus on the grid structure, wheel positioning mechanisms, also known as diverting mechanisms, container lifting mechanisms for picking up and dropping off containers to and from grid cells of the grid framework structure, and electrical or electronic components of the load handling apparatus. As mentioned above in the introduction to this patent specification, the electrical components may optionally comprise a control unit for controlling the operation of the wheel drive assemblies, wheel positioning mechanisms, and drive mechanisms of the container lifting mechanisms. Typically, the wheel drive assemblies, wheel positioning mechanisms, and drive mechanisms of the container lifting mechanisms comprise one or more electric motors. Other components of the electrical components of the load handling apparatus include, but are not limited to, a power source for providing power to drive the wheel drive assemblies and drive mechanisms of the container lifting mechanisms. Typically, the power source is a rechargeable power source or a battery. Examples of rechargeable batteries are lithium ion batteries, nickel cadmium batteries, nickel metal hydride batteries, lithium ion polymer batteries, thin film batteries, and smart battery carbon foam-based lead acid batteries.

[0045] To facilitate the description of the present invention, particularly the open frame architecture, different functional features of the load handling apparatus 130 shown in Figure 6 will be described first. However, the present invention is not limited to the examples of different functional features of the load handling apparatus described below, and other examples that can provide the same functional features of the load handling apparatus are also applicable in the present invention. The description of the functional features of the load handling apparatus is intended to provide examples of functional features of the load handling apparatus.

[0046] [Wheel Assembly] As shown in FIG. 6 , the wheel assembly includes a pair of wheels at the front and a pair at the rear of the load handling apparatus 130. For ease of explanation, the wheel assembly includes a pair of wheels at the front of the load handling apparatus and a pair of wheels at the rear of the load handling apparatus, collectively referred to as a first set of wheels 134. The first set of wheels 134 are oriented to allow the load handling apparatus to move in a first direction, i.e., an X Cartesian direction. Similar to the first direction, for movement in a second direction, the second direction is substantially perpendicular to the first direction, i.e., a Y Cartesian direction, thereby allowing the load handling apparatus to move in both the X and Y directions on the grid structure. The wheel assembly includes a pair of wheels on either side of the load handling apparatus, which for ease of explanation are referred to as a second set of wheels 136. Thus, to move in a first direction on the grid structure, the first set of wheels 134 engages the grid structure and the second set of wheels 136 disengages from the grid structure. Similarly, to move in a second direction, the first set of wheels 134 disengages from the grid structure and the second set of wheels 136 engages the grid structure. The wheels are rotatably mounted to the open frame structure 131 via one or more wheel mounts 139, 141 (see FIG. 8) and are configured to engage the grid structure to enable movement of the load handling apparatus in both the X and Y directions along the grid structure.

[0047] The load handling apparatus further includes a wheel drive assembly configured to drive each of the wheels of the wheel assembly to enable the load handling apparatus to move in the first and second directions on the grid structure.

[0048] [Wheel drive assembly] In a particular example of the invention, each of the first and second sets of wheels is driven by one or more motors (not shown) via a drive belt assembly 140, as described in PCT application PCT / EP2021 / 055372 in the name of Ocado Innovation Limited, the details of which are incorporated herein by reference. In the particular embodiment shown in Figure 6, a drive belt assembly 140 is provided for each set of wheels and includes a drive belt pulley gear arrangement 142 for engaging the edges of a pair of wheels 134, 136 on one side of the load handling apparatus. The rims of the pair of wheels include a plurality of gear teeth 144 for cooperating with a drive belt 146. A toothed drive belt engages both of the wheels. The drive belt 146 is guided by a driven wheel 148 mounted on the open frame structure 131 of the load handling apparatus 130 and two tensioning wheel arrangements 150. A tensioning wheel arrangement 150 is movably mounted to the open frame structure 131 by springs (not shown) and is intended to keep the drive belt 146 taut and maintain engagement between the drive belt and the wheels. Drive wheels 151 are provided and mounted to the open frame structure 131. The drive wheels 151 are driven by a pulley and gear arrangement 142 coupled to the axle or drive shaft of a motor (not shown in FIG. 6). Rotation of the drive wheels 151 by the motor drives the pair of wheels, which are connected to the drive belt 146. A wheel drive assembly is provided for each pair of wheels in the first set of wheels 134 and the second set of wheels 136. Thus, each of the pair of wheels in the first set of wheels 134 is synchronously driven by its respective drive assembly to move the load handling apparatus in the X direction on the grid structure. Similarly, each of the pairs of wheels in the second set of wheels 136 are synchronously driven by their respective drive assemblies to move the load handling apparatus in the Y direction on the grid structure.

[0049] The drive wheels 151 on opposite sides of the load handling apparatus 131 may share a common motor axle such that each pair of drive wheels 151 is driven simultaneously and at the same speed. As a result, only a single motor is required to drive the load handling apparatus 130 forward and reverse in the first x-direction, and only a single motor is required to drive the load handling apparatus 130 forward and reverse in the second y-direction. This configuration may advantageously reduce costs in terms of space in the load handling apparatus and the number of parts required. The first set of wheels 134 and the second set of wheels 136 may be selectively driven under the control of the load handling apparatus.

[0050] While the specific example of the wheel drive assembly in FIG. 6 includes a drive belt assembly 140 driven by a motor, other configurations for driving the first and second sets of wheels are also applicable to the present invention. It will be understood that it may be possible to drive the load handling apparatus using, for example, four motors for each of the first and second directions. For example, all of the wheels in the first and second sets of wheels may be driven by individual hub motors including outer rotors configured to rotate around inner hubs. Specifically, the outer rotors include an outer surface positioned to engage with the grid structure (e.g., tracks) and an inner surface including a ring-shaped permanent magnet positioned to rotate around the inner hub, which includes the wheel hub or the stator of the hub motor. Typically, the stator includes the coil of the hub motor. To drive each wheel of the first set of wheels 134 or the second set of wheels 136 and thus move the load handling apparatus 130 in the first or second direction on the grid structure, the outer rotors of the hub motors are positioned to rotate around axes of rotation corresponding to the central axes of the respective wheels. The outer surface of the rotor may optionally include tires for engaging a track or rail.

[0051] [Wheel positioning mechanism] To enable the load handling apparatus 130 to move in the first and second directions on different wheels 134, 136, the load handling apparatus 130 includes a wheel positioning or steering mechanism for selectively engaging either the first set of wheels 134 with the first set of tracks 22 a or the second set of wheels 136 with the second set of tracks 22 b. The wheel positioning mechanism is configured to raise and lower the first set of wheels 134 and / or the second set of wheels 136 relative to the open frame structure 131 of the load handling apparatus 130, thereby enabling the load handling apparatus 130 to selectively move in either the first direction or the second direction across the tracks of the grid framework structure 131.

[0052] The wheel positioning mechanism may include one or more linear actuators, rotary components, or other means for raising and lowering at least one set of wheels 134, 136 relative to the open frame structure 131 of the load handling apparatus 130 to move the at least one set of wheels 134, 136 into and out of contact with the tracks. In some examples, only one set of wheels is configured to be raised and lowered, and the act of lowering one set of wheels may effectively lift the other set of wheels away from the corresponding tracks, while the act of raising one set of wheels may effectively lower the other set of wheels into contact with the corresponding tracks. In other examples, both sets of wheels may be raised and lowered, advantageously meaning that the body or open frame structure 131 of the load handling apparatus 130 remains at substantially the same height, thus meaning that the weight of the body or open frame structure 131 and components mounted thereon does not need to be lifted and lowered by the wheel positioning mechanism.

[0053] In a specific embodiment of the present invention, the wheel positioning mechanism comprises a cam mechanism 152 on each side of the load handling apparatus 130. In FIG. 6, a cam mechanism 152 is shown on the visible x-direction side, with a similar cam mechanism 152 located on the opposite x-direction side (not shown). Similarly, a cam mechanism 152 is shown on the visible y-direction side, with a similar cam mechanism 152 located on the opposite y-direction side (not shown). In other words, the cam mechanism 152 on each side of the load handling apparatus 130 is configured to raise and lower a pair of wheels relative to the open frame structure 131 of the load handling apparatus 130. Each cam mechanism 152 on the opposing sides of the load handling apparatus is configured to synchronously raise and lower a respective pair of wheels of the first set of wheels 134 or the second set of wheels 136 relative to the open frame structure 131 of the load handling apparatus 130 in order to move the load handling apparatus in the x-direction or y-direction on the grid structure. In particular, cam mechanism 152 includes a cam 154 having a cam profile 156 and a cam follower 158 engageable with cam profile 156. In the particular embodiment of the invention shown in Figure 6, cam follower 158 is a roller that rotates freely about a rotating shaft or spigot. Cam follower 158 is configured to move along the length of cam profile 156.

[0054] Cam 154 includes a slot having a contour 156 extending longitudinally along the slot between a first or lower limit 160 (valley) and a second or upper limit 162 (highland). Between these limits, the slot extends substantially horizontally from lower limit 160, slopes upward, and continues substantially horizontally to upper limit 162 with sufficient space to accommodate cam follower 158. Movement of cam follower 158 from lower limit 160 to upper limit 162 causes one or more wheels of first set of wheels 134 or second set of wheels 136 to move upwardly and out of engagement with the track. Similarly, movement of cam follower 158 from upper limit 162 to lower limit 160 causes one or more wheels of first set of wheels 134 or second set of wheels 136 to move downwardly and into engagement with the track. One or more wheels of the first set of wheels 134 or the second set of wheels 136 may be coupled to either the cam 154 or the cam follower 156 via its respective wheel mount such that movement of the cam follower 156 relative to the cam 154 lowers and raises one or more wheels of the first set of wheels 134 or the second set of wheels 136.

[0055] A pair of wheels on the same side of the load handling apparatus may share the same cam and cam follower such that movement of the cam follower along the cam simultaneously raises or lowers the pair of wheels. A pair of wheels on opposite sides of the load handling apparatus represents a first set of wheels for moving the load handling apparatus in the X direction, and a pair of wheels on the other opposite side of the load handling apparatus represents a second set of wheels for moving the load handling apparatus in the Y direction. In other words, the cam mechanism provides a single cam configuration in which pairs of wheels on either the first or second set of wheels on the side of the load handling apparatus are lowered or raised by the same cam and cam follower. However, in the particular embodiment of the invention shown in FIG. 6, the cam mechanism 152 uses a double cam configuration rather than a single cam configuration on each side of the load handling apparatus. The first and second cams are horizontally adjacent. The first and second cam profiles are substantially identical. Similarly, a pair of followers is positioned to engage each cam. Thus, instead of a single cam arrangement for raising and lowering a pair of wheels, a double cam arrangement on one side of the load handling apparatus provides for movement of a pair of wheels on one side of the load handling apparatus in the raised and lowered positions. The use of a double cam arrangement, rather than a single cam arrangement on each side of the load handling apparatus, maintains the horizontal orientation of a pair of wheels of the first or second set of wheels when moving in the raised or lowered position. However, the cam mechanism is not limited to a double cam arrangement on each side of the load handling apparatus, but may comprise a single cam arrangement on each side of the load handling apparatus.

[0056] To move the cam follower 158 relative to the cam 154, in certain embodiments of the invention, the cam mechanism 152 includes a traveler 164 configured to move along a side of the load handling apparatus. Coupled to the traveler 164 is the cam follower 158, such that movement of the traveler 164 along one side of the load handling apparatus 130 raises and lowers one or more wheels in the first set of wheels 134 or the second set of wheels 136. The traveler 164 may be configured to move along rails 166 (see FIG. 8 ) on each side of the load handling apparatus, such that movement of the traveler 164 along the rails 166 moves the cam follower 158 along the cam 154, which in turn raises one pair of wheels in the first or second set of wheels when the cam follower is at an upper limit 162 and lowers one or more wheels when the cam follower is at a lower limit 160 of the cam 154. In this particular example of the present invention, rails 166 for supporting travelers 164 are integrally formed from the open frame structure 131 of the load handling apparatus 130 .

[0057] The traveler 164 is configured to move along the rail 166 by a cam drive mechanism including a cam motor 168 coupled to the traveler 164 via one or more pulleys, spools, belts, and / or gears to move the traveler along one side of the load handling apparatus. In a particular embodiment of the invention, the motor 168 is configured to move the traveler 164 along one side of the load handling apparatus by a cam belt 170 having one end affixed to the cam motor 168 and the other end affixed to the traveler 164. The cam belt 170 is wound onto a cam spool attached to the drive shaft of the cam motor 168 such that rotation of the cam spool by the cam motor 168 imparts a pulling force to the cam belt 170, which in turn moves the traveler 164, which is affixed to the cam belt 170, along the rail 166. To return the traveler 164 to its initial position, a second motor may impart an opposing pulling force to the traveler 164 to pull the traveler in the opposite direction. Alternatively, the traveler may be biased by a biasing force (e.g., a spring) toward a first position corresponding to the lower or upper limit of the cam profile, and the motor is configured to apply a pulling force to the traveler against the biasing force to move the traveler toward a second position corresponding to the upper or lower limit of the cam profile. Preferably, the cam motor 168 is mounted to the open frame structure 131 to provide the anchorage necessary to raise and lower the pair of wheels of the load handling apparatus relative to the open frame structure.

[0058] To provide synchronized movement of the first or second set of wheels in the X or Y direction on the grid structure, corresponding travelers for the first or second set of wheels on opposite sides of the load handling apparatus can be moved by one or more cam motors. For example, a single cam motor can provide a pulling force to raise or lower the first set of wheels 134. Similarly, a single cam motor can provide a pulling force to raise or lower the second set of wheels 136. Alternatively, two cam motors can provide opposing pulling forces on the travelers to raise and lower each pair of wheels in the first or second set of wheels. In the particular example of the invention shown in FIG. 6, two cam motors are used to synchronously raise and lower the first and second sets of wheels. To provide synchronized movement of the first and second sets of wheels, each of the two cam motors is configured to rotate in both clockwise and counterclockwise directions. A plurality of cam belts 170 are wrapped around the periphery of the open frame structure 131 of the load handling apparatus 130 via connections to travelers and cam motors 168, such that clockwise rotation of the two cam motors raises the first set of wheels 134 and lowers the second set of wheels 136. Conversely, counterclockwise rotation of the two cam motors 168 raises the first set of wheels 134 and lowers the second set of wheels 136.

[0059] While the particular example of a wheel positioning mechanism shown in Figure 6 includes a cam mechanism driven by a cam motor, other configurations of wheel positioning mechanisms are also applicable in the present invention. For example, the wheel positioning mechanism may include a compliant mechanism having at least one elastically deformable member configured to move under an applied force, such as a motor, to raise or lower the wheels, as taught in PCT application PCT / EP2021 / 055335 in the name of Ocado Innovation, the details of which are incorporated herein by reference. In particular, the first and second sets of wheels may be raised off the rails or lowered onto the track or rails by compliant mechanism(s) or linkage sets attached to an open-frame structure on opposite sides of the load handling apparatus.

[0060] The turning compliant mechanisms are deformable in a first and second direction, respectively. When there is no input force, the compliant mechanisms are at rest or in a neutral position, i.e., they are not elastically deforming and both sets of wheels are at the same height and resting on a surface. In this configuration, the load handling apparatus cannot move in either the x or y direction and is stationary. The elastic deformation of the compliant mechanisms is linked to arms that hold each of the wheels and are movable in the vertical (or z) direction to raise and lower the wheels.

[0061] When a first input force F1 is applied, the compliant mechanism body deforms in a first direction. The displacement of the mechanism body is translated vertically, lowering the first set of wheels 134 and raising the second set of wheels 136. The wheels of the first set of wheels move downward to engage the rails or tracks and support the vehicle, and the wheels of the second set of wheels move upward to clear the tracks. Thus, the load handling apparatus 130 can be driven in the X direction.

[0062] When a second input force F2 is applied in a direction opposite to the first input force, the compliant mechanism body deforms in a second direction. The displacement of the mechanism body is translated into vertical movement to raise the first set of wheels 134 and lower the second set of wheels 136, so that the load handling apparatus can be supported by the second set of wheels 136 and driven in the y direction.

[0063] The compliant mechanisms are connected via transmission linkages to these sets of wheels 134, 136. Thus, in this manner, the compliant mechanisms provide a means for changing the direction of forward motion of the load handling apparatus 130.

[0064] [Container lifting mechanism] To retrieve storage containers stored in the grid framework structure, the load handling apparatus includes a container lifting mechanism or assembly including a grabber device or container gripper assembly for releasably grasping a storage container from the stack and lifting the storage container into a container receiving space of the load handling apparatus. A winch or crane assembly including multiple lifting tethers wound on separate spools, one end of which is secured to the grabber device, is used to lift and lower the grabber device. The container receiving space is sized to accommodate the dimensions of the storage container. The container receiving space may be within the open frame structure of the load handling apparatus, as shown in FIG. 6, or may be adjacent to the open framework structure in a cantilever configuration, with the weight of components housed within the open frame structure balancing the weight of the storage container to be lifted by the container lifting mechanism.

[0065] The grabber device 170, as shown in FIG. 7, is formed as a frame having four corner sections, a top side, and a bottom side. The lifting mechanism is used to lift a container into the container-receiving space of the load handling device. For maximum stability and load capacity, four lifting tethers 38 (see FIG. 5b) are typically used to hoist the grabber device 170, with one tether located near or at each corner of the grabber device 170, although different configurations, e.g., having fewer tethers, can be used as needed. One end of each of the tethers, e.g., the first end, is wound onto a spool in the load handling device, and the other end, e.g., the second end, is typically secured to the grabber device 170 by suitable brackets (not shown) at each corner of the grabber device. The number of tethers attached to the grabber device depends on the ability of the grabber device to remain horizontal during operation when picking up a container 10 and to withstand the tension applied to the tether when lifting a container, which can weigh up to 40 kg, without stretching or stretching, i.e., to be inextensible under a given applied tensile stress. In order to have the required physical properties (Young's modulus), the tethers are generally in the form of cables, e.g., ropes or even tapes, although other tethers having the required physical properties for hoisting a container are also acceptable in the present invention.

[0066] To grasp the container 10, the grabber device 170 includes four locating or guide pins 172 near or at each corner of the grabber device 170 that fit into corresponding notches or holes formed in the four corners of the container 10, and four gripper elements 174 located on the bottom side of the grabber device 170 for engaging the rim of the container. The locating pins 172 help to properly align the gripper elements 174 with the corresponding holes in the rim of the container.

[0067] Each of the gripper elements 174 includes a pair of wings 176 that are foldable to be received in a corresponding hole in the rim of a container and an open, expanded configuration having at least one dimension larger than the hole in the rim of the container to lock onto the container. The wings 176 can be driven into the open configuration by a drive gear. More specifically, the head of at least one of the wings includes a plurality of teeth that mesh with the drive gear, such that when the gripper element 174 is actuated, rotation of the drive gear rotates the pair of wings from the folded configuration to the open, expanded configuration.

[0068] When in the folded or closed configuration, the grabber elements 174 are sized to be receivable in corresponding holes 86 in the rim of a container. The legs of each of the pair of wings include stops 178, e.g., bosses, so that when received in corresponding holes in the rim of a container, the stops engage the underside of the rim when in the expanded open configuration to lock onto the container as the grabber device 170 is rolled upwardly toward the container-receiving portion of the load handling equipment.

[0069] Turning to the winch assembly of the container lifting mechanism, the winch assembly comprises a drive mechanism and four tethers wound onto four separate spools 180 (see FIG. 6 ). The four tethers extend downwardly from their respective four spools 180 such that the lower end of each tether connects to a grabber device 170. The four spools 180 may be attached to separate rotatable or lifting shafts, or alternatively, may be attached to the same or a common rotatable or lifting shaft 182. In a particular embodiment of the invention shown in FIG. 8 a, the lifting mechanism includes a central, horizontally extending lifting shaft 182 and four spools, two spools 180 at a first end of the lifting shaft 182 and two spools 180 at a second end of the lifting shaft 182; i.e., the four separate spools carrying the lifting tethers are attached to a single rotatable shaft 182 such that the rotatable shaft is common to all four separate spools. As a result, each of the four tethers connected to grabber device 170 is connected to its own spool, such that a single tether is wound or unwound onto each spool. This advantageously ensures that the wound tether on each spool takes up less space compared to embodiments in which two or more tethers are wound onto a single spool. Providing a spool for each tether also advantageously reduces the risk of the tethers becoming tangled when winding and unwinding the tethers to raise and lower the grabber device.

[0070] The lifting shaft 182 is configured to rotate to wind or unwind a tether around each spool. As the lifting shaft rotates in a first rotational direction to wind the tether, each tether is simultaneously wound around its respective spool to lift the grabber device 170 (and the container, if grasped by the grabber device). The lifting shaft 182 is rotated in a second rotational direction (opposite to the first rotational direction) to simultaneously unwind each tether from its respective spool, thereby lowering the grabber device 170 (and the container, if grasped by the grabber device). The tethers are wound or unwound simultaneously and at the same speed to evenly and steadily lift or lower the grabber device 170. The lifting shaft 182 and four pulleys for guiding each of the four lifting tethers to each of the four corners of the grabber device are attached to the open frame structure of the load handling apparatus.

[0071] The lifting assembly includes a motor (not shown) configured to rotate a lifting shaft 182 in first and second rotational directions to wind or unwind the tether around the spools. The motor is coupled to a central, horizontally extending lifting shaft 182 to rotate the lifting shaft 182 in the first and second rotational directions. Various mechanisms may be used to couple the motor to the lifting shaft, including, but not limited to, at least one of a plurality of timing pulleys, timing belts, and / or gears to transmit rotation from the output of the motor to the lifting shaft. In a specific embodiment of the invention, the lifting shaft 182 is coupled to the motor via a timing belt and a drive pulley attached to the lifting shaft 182 common to all four spools 180 carrying the lifting tether, such that rotation of the drive pulley attached to the lifting shaft through its connection to the motor via the timing belt drives rotation of all four spools common to the lifting shaft.

[0072] The present invention is not limited to the container lifting mechanism described above with reference to FIG. 6 , and other container lifting mechanisms for retrieving storage containers from a grid framework structure of a storage and retrieval system are also applicable in the present invention. For example, the container lifting mechanism may be based on the container lifting mechanism taught in PCT / EP2021 / 051531 in the name of Ocado Innovation Limited, the details of which are incorporated by reference. In PCT / EP2021 / 051531, the container lifting mechanism comprises a first set of spools and a second set of spools, and a rotatable shaft, wherein each spool of the first set of spools and the second set of spools carries a lifting tether having a first end secured to a grabber device and a second end secured to the spool. The spools of the first set are attached to the rotatable shaft such that the rotatable shaft is common to the spools of the first set. A drive pulley and a first set of timing pulleys are attached to the rotatable shaft and are common to the first set of spools, such that rotation of the rotatable shaft by a single motor connected to the drive pulleys drives the first set of spools, and a second set of timing pulleys are connected to the first set of timing pulleys via one or more of the timing belts, such that rotation of the rotatable shaft by a single motor connected to the drive pulleys drives the second set of spools.

[0073] [Open frame structure] Returning to the modular construction of the load handling apparatus to accommodate different functional features of the load handling apparatus shown in Figure 8a, the different modular sections 132a, 134a, 136a, 138a of the load handling apparatus can be envisioned by the construction of simplified modular blocks 132b, 134b, 136b, 138b forming a vertically stacked layered structure shown in Figure 8b. In a particular embodiment of the invention, four modular sections 132(a and b), 134(a and b), 136(a and b), 138(a and b) are shown in a vertical stack, with each of the four modular sections providing one or more of the functional features of the load handling apparatus. For purposes of this description, the four modular sections, labeled in ascending order of height of the load handling apparatus, comprise first, second, third, and fourth modular sections, with first modular section 132(a and b) at the bottom of the load handling apparatus and fourth modular section 138(a and b) at the top of the load handling apparatus. As shown in Figures 8(a and b), each of the four modular sections carries at least a portion of one or more of the functional components of the load handling apparatus. The number and location of the different modular sections within the layered structure is not limited to the four modular sections shown in Figures 8(a and b) and may include or be shared among any number of modular sections that provide additional functional features of the load handling apparatus.

[0074] Each modular section can be envisioned as a rectangular open frame formed by connecting or interlocking corner brackets together, where each corner bracket is shown as a connecting block in FIG. 8b. The modular sections are constructed by connecting adjacent connecting blocks in the same horizontal plane with one or more connecting elements 184 to form an open rectangular frame 186. Thus, vertically adjacent rectangular frames 186 are connected together by connecting vertically adjacent connecting blocks 140 to form the open frame structure 131, as shown in FIGS. 9(a) and 9(b). An example of a connecting block 140 is a corner bracket. In a single modular section, each corner bracket is connected to two other corner brackets in the same horizontal plane by one or more connecting elements 184. The connecting elements can be connecting rods or tubes to connect adjacent connecting blocks (corner brackets) together in a single modular section. The connecting rods can be solid or hollow, depending on the connections with the connecting blocks, as further explained below. In certain embodiments of the present invention, the open frame structure is a three-dimensional structure defining a volume having an upper portion for housing the power supply 180, the control unit 192, and the spool 182 carrying the lifting tether, and a lower portion for housing the container receiving space 137.

[0075] The structural integrity of the open frame structure should be sufficient not only to support the different functional features of the load handling apparatus, but also to have sufficient bending stiffness when the load handling apparatus is operable on the grid structure. Various materials can be used in the fabrication of the connecting rods or tubes. These include, but are not limited to, metals, polymers, ceramics, or combinations thereof. To reduce the weight of the load handling apparatus and provide the structural properties necessary to support the different functional components of the load handling apparatus, the connecting rods that connect adjacent corner brackets together are optionally constructed of carbon fiber bonded in a polymer matrix (known as carbon fiber rods). To aid in the construction of the rectangular frames that form the modular sections, each of the connecting blocks of one or more of the modular sections includes an opening or socket 187 (see Figures 10 and 11) for the insertion of a connecting rod. The connecting rods are secured to the connecting blocks by joints. Various joints can be used to secure the connecting rods to the corner brackets in the modular sections. These include various fasteners, glue, welding, etc. Further details of the joints that secure the connecting blocks to the connecting rods are described below.

[0076] A simplified modular section is one in which the connecting blocks 140 are corner brackets, such that the modular section includes four corner brackets. Each of the four corner brackets is directly connected to two other corner brackets in the same horizontal plane to form a simple open rectangular frame, as shown in FIG. 8b. However, the corner brackets in a single modular section may be indirectly connected to two other corner brackets by one or more connecting blocks intermediate the corner brackets at the corners of the rectangular frame, as shown clearly in FIG. 8a. Thus, the term "connected" with respect to the corner brackets in each modular section may be broadly interpreted to mean directly and / or indirectly connected to two other corner brackets.

[0077] To construct a load handling apparatus according to the present invention, different modular sections may be connected together by simply connecting vertically adjacent rectangular frames 186 together via their respective corner brackets 140 with one or more vertical connecting elements 188 to form an open frame structure 131 as shown in the simplified open frame structure in FIGS. 8a and 8b. In other words, the same corner bracket used to connect to two other corner brackets in a single modular section may be used to vertically connect adjacent rectangular frames together. The corner brackets of vertically adjacent rectangular frames may be attached to the same vertical connecting element 188 at each corner of the open frame structure such that the vertical connecting element extends through the corner brackets of multiple vertically adjacent rectangular frames. As a result, each of the corners of the open frame structure share the same or common vertical connecting element. To connect multiple rectangular frames to the same vertical connecting element at each corner of the open frame structure via their respective corner brackets, the corner brackets intermediate or between the bottom and top rectangular frames have one or more through-holes for the vertical connecting element to extend through the corner bracket when connecting vertically adjacent rectangular frames 186 together (see the second modular section in FIG. 8a). This has the advantage that multiple rectangular frames 186 can be connected together vertically in a stack by simply attaching multiple rectangular frames to the same vertical connecting element at each corner of the open frame structure to form a load handling apparatus such as that shown in FIGS. 8(a) and 8(b). Alternatively, separate vertical connecting elements can be used to connect vertically adjacent rectangular frames at each corner of the open frame structure. The length of the vertical connecting elements connecting vertically adjacent rectangular frames determines the height of the load handling apparatus. The connecting elements 188 connecting vertically adjacent rectangular frames together can be the same type or different types of connecting elements as the connecting elements connecting adjacent corner brackets in the same horizontal plane.For example, the connecting elements 188 that connect vertically adjacent rectangular frames together can be connecting rods used to connect corner brackets in a single modular section. The connection of corner brackets to one another to form a connecting block by horizontal connecting rods 184 and vertical connecting rods 188 is shown in Figures 10-12. Figures 10-12 show the assembly of different modular sections of a load handling apparatus, where Figure 10 represents the assembly of a first modular section with wheel mounts 139, 141, Figure 11 represents the assembly of a second modular section with supports or rails 166 for the travelers of the cam mechanism of the wheel positioning mechanism described above, and Figure 12 is a fourth modular section for supporting the electrical components and power supply of the load handling apparatus. The block construction of modular sections is best shown in Figures 10-12, where each corner bracket or connecting block 140 includes one or more sockets 187 shaped to receive one or more connecting rods or tubes 184, 188 for joining the connecting blocks together to form a single modular section, with vertically adjacent modular sections being joined together in a vertical stack. The arrows in Figures 10-12 indicate the orientation of the connecting rods or tubes 184 when inserted into their respective sockets 187 in the connecting blocks or corner brackets 140.

[0078] To simplify the construction of the load handling apparatus while still accommodating different functional features of the load handling apparatus, at least a portion of the functional components of the load handling apparatus are integrated into the open frame structure 131 of the load handling apparatus 130 in the sense that at least a portion of the functional components of the load handling apparatus are integral with one or more of the rectangular frames of the load handling apparatus. For example, at least a portion of the wheel assembly is integral with one or more rectangular frames, at least a portion of the wheel drive assembly is integral with one or more rectangular frames, at least a portion of the wheel positioning mechanism is integral with one or more rectangular frames, and / or at least a portion of the container lifting mechanism is integral with one or more rectangular frames.

[0079] To integrate at least a portion of the different functional features of the load handling apparatus with one or more of the rectangular frames 186 that form the open-frame structure of the load handling apparatus, one or more of the connecting blocks 140 of one or more of the rectangular frames 186 are fabricated with the functional features of the load handling apparatus in mind. At least a portion of one or more of the functional components of the load handling apparatus are integrated into one or more connecting blocks of one or more of the rectangular frames. For example, one or more of the corner brackets that connect the rectangular frames together may be integrally formed with one or more mounts for the spools, pulleys, and / or motors rather than having separate mounts for attaching to the frame of the load handling apparatus.

[0080] The simplest of the modular sections in certain embodiments of the present invention is the fourth or top modular section. The rectangular frame 186 of the fourth or top modular section, shown in FIG. 6, provides support for electrical components of the load handling apparatus, such as a control unit 192 and / or power supply 190 for controlling the operation of the wheel drive assemblies and / or wheel positioning mechanisms and / or container lifting mechanisms. In certain embodiments of the present invention, one or more electrical components of the load handling apparatus are supported in one or more cradles 194, which are in turn supported by the rectangular frame. Cross beams or rods 185 extend across the rectangular frame 186 of the fourth or top modular section to support one or more electrical components of the load handling apparatus, as shown in FIG. 8a. As a result, each of the corner brackets 140 of the rectangular frame of the top modular frame is indirectly connected to two other corner brackets in the same horizontal plane via connecting blocks intermediate the corner brackets. The opposing connecting blocks intermediate the corner brackets are connected together to form cross beams or rods that extend across the rectangular frame, as shown in Figure 8a. The rectangular frame of the top modular section is formed by connecting the connecting blocks, including the corner brackets, together with one or more connecting elements, as shown in Figure 12.

[0081] Different connection blocks can be used to construct different modular sections, and the choice of connection block will largely depend on the different functional features of the load handling apparatus. The simplest corner bracket or connection block 140b is shown in FIG. 13, as the rectangular framework of the top modular section provides minimal function to the load handling apparatus, except for supporting the power and control units. Here, each corner bracket or connection block of the top modular section has three openings or sockets 187 (see FIG. 13): two for connecting to two other connection blocks in the same horizontal plane via separate connection elements, and a downward-extending socket for joining the top modular section to a vertically adjacent rectangular frame in a vertical stack. Because at least a portion of the functional components of the load handling apparatus are integrated into the open frame structure, more specifically, the connecting blocks of the open frame structure, the shape of the connecting blocks becomes more complex as the complexity of the functional features of the load handling apparatus increases, i.e., lower down the load handling apparatus with the container lifting mechanism, wheel drive assembly, and wheel assemblies. Examples of various complex connecting blocks 140(b-e) forming corner brackets of the open frame structure are shown in Figures 13-16, representing different corner brackets for assembling the rectangular frames of different modular sections of the load handling apparatus.

[0082] Various lightweight materials may be used in the fabrication of the connecting blocks. Examples of lightweight materials include, but are not limited to, various light metals, such as aluminum, or various polymeric materials, such as plastic materials, or composite materials (e.g., carbon fiber / polymer composites). Various methods may be used to create the connecting blocks. These include, but are not limited to, machining from a block, injection molding, or casting. However, as the complexity of the connecting blocks increases, particularly when at least a portion of a functional component of the load handling apparatus is integrated with the connecting blocks 140, 140(b-e), more sophisticated fabrication methods may be used. The use of additive manufacturing, such as 3D printing, provides the ability to fabricate complex connecting blocks, whereby at least a portion of a functional component of the load handling apparatus may be integrally formed with one or more of the connecting blocks. The use of additive manufacturing in the fabrication of the connecting blocks, particularly the corner brackets, allows one or more of the connecting blocks to be topology optimized to account for the stresses the connecting block would experience in an open-frame configuration. This is because additive manufacturing or 3D printing has the ability to form complex shapes that cannot be achieved by machining alone. This is especially true when the connection block is topology optimized, as the results of topology optimization tend to result in complex shapes to take into account the various loading constraints that the connection block will face in its application in an open frame structure of a load handling device.

[0083] The wheels of the wheel assemblies are supported by the rectangular frame 186 in the lowermost or first modular section. To accommodate the wheels of the wheel assemblies, the connecting blocks of the lowermost or first modular section, more specifically, each of the corner brackets, are integrally formed with one or more wheel mounts 139, 141 for the first and second sets of wheels. In the particular embodiment of the invention shown in FIG. 16, each of the corner brackets 140e of the lowermost modular section is formed in two parts to accommodate two wheel mounts, i.e., first and second wheel mounts 139, 141. The first wheel mount 139 is configured to mount a wheel from the first set of wheels 134, and the second wheel mount 141 is configured to mount a wheel from the second set of wheels 136 (thus, there are a total of eight wheels mounted on four corner brackets 140e, with two wheel mounts per each of the four corner brackets 140e, arranged to support the open frame structure of the load handling apparatus). In other words, each of the four corner brackets 140e of the first, or lowermost, modular section is integrally formed with two wheel mounts, namely, first and second wheel mounts 139, 141. To accommodate two wheel mounts on one corner bracket 140e, the two wheel mounts of a given corner bracket are assembled substantially perpendicular to one another, such that the first wheel mount 139 provides a mount for a wheel for moving the load handling equipment in a first direction, and the second wheel mount 141 provides a mount for moving the load handling equipment in a substantially vertical direction. In the particular embodiment of the invention shown in Figures 10 and 16, the first and second wheel mounts 139, 141 of the corner brackets include shafts or spigots for rotatably mounting the respective wheels.

[0084] As also shown in FIG. 10 and best seen in FIG. 16, the edge or end of each of the first and second wheel mounts of a given corner bracket 140e includes one or more bosses or fingers 196 having vertically aligned or concentric openings for receiving connecting elements 188 through the openings in the one or more bosses. The one or more bosses 196 on the edges of the first and second wheel mounts 139, 141 are spaced apart so that the bosses 196 of both the first and second wheel mounts of a given corner bracket interlock with each other and the openings in their respective bosses are axially aligned along the wheel positioning axis WW (see FIG. 16) for receiving connecting elements 188 when the bottom, or first, modular section is vertically coupled to the second modular section directly above, as shown in FIG. 8a. The wheel positioning axis WW is the axis along which the respective first set of wheels or second set of wheels are raised or lowered depending on the direction of movement on the grid structure. 16, the wheel positioning axis WW is shown as a vertical axis along which the wheels of the first and second sets are raised and lowered. For a given corner bracket, the bosses 196 on the edges of the first and second wheel mounts 139, 141 of the corner bracket 140e are spaced apart sufficiently so that, when the spaced bosses interlock, each of the first wheel mount 139 or second wheel mount 141 of the corner bracket 140e can move along its vertical connecting element, i.e., along the wheel positioning axis WW, independently of the other pair of wheels of the second set. This allows a pair of wheels of the first set of wheels to be raised or lowered independently of a pair of wheels of the second set of wheels when attached to the corner bracket. This is repeated for the other corner brackets of the bottom modular section so that all four corner brackets of the bottom modular section provide wheel mounts for supporting all eight wheels in the first and second sets of wheels. Each corner bracket wheel mount includes an integrally formed wheel shaft 198 for rotatably mounting the wheel on a shaft.Each corner bracket 140e for mounting the wheels of the wheel assembly is connected to two other corner brackets to form a rectangular frame by one or more connecting elements 184. In the particular example of the invention shown in Figures 8a and 9a, each of the corner brackets 140e is connected to two other corner brackets in the same horizontal plane by two connecting rods 184 that are receivable in openings or sockets 187 in the corner brackets (see Figure 10). However, the number of connecting elements 184 for connecting adjacent corner brackets in the same horizontal plane to form the rectangular frame of the first modular section comprising the wheel assembly is not limited to two connecting elements, but can be any number of connecting elements to provide the required structural rigidity of the rectangular frame.

[0085] To drive the rotation of the first and second sets of wheels, at least a portion of the wheel drive assemblies described above may be integrated into one or more of the rectangular frames of the open-frame structure of the load handling apparatus. When the wheel drive assemblies include the drive belt assemblies 140 on each side of the load handling apparatus described above, mounts for the drive wheels and driven wheels for carrying the drive belt may be integrally formed with one or more of the connecting blocks 140e (see FIG. 16) of one or more of the rectangular frames. For example, in the particular embodiment of the invention shown in FIG. 16, each of the corner brackets 140e that include wheel mounts 139, 141 for the wheel assemblies additionally includes a mount 198 for the driven wheel 148 of the drive belt assembly, such that the drive belt travels around the periphery of the wheels 134, 136 attached to the corner bracket 140e and around the driven wheel 148 on the same corner bracket 140e (see FIGS. 6 and 16). Each corner bracket 140e is integrally formed with two wheel mounts 139, 141 for wheels oriented perpendicular to one another to cover the direction of travel of the load handling apparatus on the grid structure, so that mounts 198 for their respective driven wheels can be integrally formed with each of the wheel mounts 139, 141 of the corner bracket 140e. Drive pulleys for driving the rotation of a pair of wheels of the first or second set of wheels are attached to the corner bracket 140d of the rectangular frame located higher in the vertical stack so that a drive belt extends around a pair of wheels on one side of the load handling apparatus and around a drive wheel attached to the higher modular section. In a specific embodiment of the invention, the drive wheels for driving the drive belts of each wheel drive assembly are attached to shafts or spigots 202, 204 integrally formed with the corner bracket 140 forming the rectangular frame of the second modular section. As a result, each pair of wheels in the first and second sets of wheels is driven by a drive belt connecting driven wheels in the first modular section and drive wheels attached to corner brackets of the second modular section.This is repeated for the other drive assemblies on each side of the load handling apparatus, as shown in Figure 6. Figure 6 also shows that each wheel drive assembly for driving a pair of wheels additionally includes the tensioning wheel arrangement described above to ensure that the drive belt around a given pair of wheels remains taut. In the particular example of the load handling apparatus shown in Figure 6, one or more of the corner brackets of the rectangular frame that support the wheels also include a wheel tensioning arrangement.

[0086] The drive assembly is not limited to the drive belt assembly described above, and the connecting blocks of the rectangular frame that carry the wheels of the wheel assembly may be integrated with the mountings for carrying the hub motors described above. Thus, each corner bracket of the rectangular frame of the first or lowest modular section may be integrally formed with a mounting for a drive assembly that includes a hub motor, where the inner hub of the hub motor is attached to the corner bracket. Since each corner bracket of the first or lowest modular section is formed with two wheel mountings for mounting two wheels, each corner bracket is integrally formed with two mountings for mounting two hub motors, one for mounting the wheel in a first direction and the other for mounting the wheel in a second direction.

[0087] To turn on the grid structure, the load handling apparatus includes a wheel positioning mechanism. Various wheel positioning mechanisms are known in the art, some of which have been described above. Considering the need for sufficient force to lift a pair of wheels from a given set of wheels vertically relative to the open-frame structure, at least a portion of the wheel positioning mechanism is attached to a rectangular frame of the open-frame structure that is reinforced to support the weight of a pair of wheels on each side of the load handling apparatus. In the specific example of a load handling apparatus shown in FIGS. 6 and 11, the rectangular frame of the second modular section is reinforced by one or more struts or braces 206 and is referred to as a "middle halo" because it is located substantially in the middle of the height of the load handling apparatus. Reinforcement of the middle halo is provided by one or more cross braces 206 extending across the rectangular frame. The specific example of the wheel positioning mechanism shown in FIG. 6 is based on the cam mechanism described above, which includes a cam, a cam follower movable along the cam, and a traveler for moving the cam follower. The traveler is configured to move along a rail 166 on one side of the load handling apparatus to raise the pair of wheels. The rail 166 for supporting the traveler for raising the pair of wheels includes horizontal connecting elements extending between the corner brackets of the rectangular frame of the intermediate harrow so that the traveler moves along connecting elements 184 connecting the corner brackets 140 on one side of the load handling apparatus. Thus, the connecting elements for supporting the traveler of the intermediate harrow function as overhead rails. In the specific example of the invention shown in FIG. 6, the traveler is slidably attached to connecting elements connecting the corner brackets in the same horizontal plane. This is repeated for the other pairs of wheels on each side of the load handling apparatus. At least two connecting elements 184 extend between the corner brackets 140 on one side of the load handling apparatus to support the traveler.One or more inserts 208 are sandwiched between the two connecting elements 184 extending between the corner brackets 140 to provide bending stiffness to the connecting elements extending between the corner brackets 140 to prevent the connecting elements from bending excessively as the traveler moves along the connecting elements. In a particular example of the invention, the cam mechanism for each pair of wheels in the first and second sets of wheels is based on a double cam configuration as described above, where the traveler is configured to raise and lower a given pair of wheels via the double cam configuration. The cams for cooperating with the cam followers may be attached to the corner brackets that support the wheels of the wheel assemblies or may be formed integrally with the corner brackets. In the double cam configuration on each side of the load handling device, two cams are attached to each corner bracket that cooperate with two respective cam followers to cater for vertical movement of the wheels oriented in the first and second directions (see FIG. 15). Thus, for a given corner bracket, a first cam is attached to or integrally formed with a first wheel mount of the corner bracket, and a second cam is attached to or integrally formed with a second wheel mount of the corner bracket, so that when both the first and second wheel mounts of the corner bracket are brought together, the cams on different sides of the load handling device cooperate with their respective cam followers. Similar corner brackets are used to mount the other wheels of the wheel assembly.

[0088] As the cam follower moves along the cam, an upward or downward force is applied to the respective corner bracket carrying a wheel of the first or second set of wheels, which raises or lowers the wheel depending on the direction of travel of the load handling apparatus over the grid structure. As described above, each corner bracket for mounting a wheel of the wheel assembly is formed from two interlocking parts, a first part 139 and a second part 141, each of which includes a wheel mount for the wheel. The first part provides a wheel mount for a wheel of the first set of wheels, and the second part provides a wheel mount for a wheel of the second set of wheels, defined as first wheel mount 139 and second wheel mount 141, respectively. Bosses or fingers 196 on the edges of the first and second wheel mounts are sufficiently spaced apart so that, when the bosses interlock, the first wheel mount can move axially along its connecting vertical connecting element independently of the second wheel mount. When the vertical connecting element is a connecting rod, the diameter of the opening in one or more bosses of each of the corner bracket's first and second wheel mounts is slightly larger than the diameter of the connecting rod 188, thereby allowing the corner bracket's first and second wheel mounts 139, 141 to be vertically movable when a force is applied in the vertical direction. The cam 154 cooperating with the cam follower 158 may be integrally formed with its respective corner bracket 140e that comprises the wheel mount of the wheel assembly, as shown in FIG. 16. Two cams 154 are shown integrally formed with the corner bracket 140e, one for each of the wheel mounts 139, 141. As can be understood from the above description in connection with FIGS. 6 and 16, at least a portion of the wheel positioning mechanism is integrally formed with the connecting blocks, and more particularly, the corner brackets, of one or more rectangular frames that form the different modular sections of the load handling apparatus.

[0089] FIG. 6 also shows that a motor for moving the traveler along the connecting element is attached to a corner bracket 140d of the rectangular frame forming the intermediate harrow of the open-frame structure. One or more mounting bases for one or more motors are integrally formed with the connecting block, more specifically, with the corner bracket of the rectangular frame of the intermediate harrow. As shown in FIG. 15, one or more openings 210 are integrally formed in the corner bracket 140d to receive the motor shaft of the motor. The corner bracket 140d also supports a spool for winding a belt connected to the traveler as the spool rotates, such that when the motor rotates clockwise, the belt is wound onto the spool and when the motor rotates counterclockwise, the belt is unwound from the spool.

[0090] In addition to at least a portion of the wheel positioning mechanism being integrally formed with the connecting blocks or corner brackets forming the rectangular frame of one or more modular sections, at least a portion of the container lifting mechanism, more specifically, the winch assembly, is integrally formed with the rectangular frame of one or more modular sections. Lifting shafts for driving the rotation of four spools carrying lifting tethers connected to grabber devices are rotatably attached to the rectangular frame of the modular sections. In the example shown in FIG. 8a, lifting shaft 182 is rotatably attached to the rectangular frame of the third modular section. FIGS. 8a and 9a show lifting shaft 182 extending across the rectangular frame. Opposite ends of the lifting shaft are rotatably attached to connecting elements connecting adjacent corner brackets via respective connection blocks 212. Four lifting pulleys 214 of the container lifting mechanism, one at each corner of the lifting assembly, are attached to respective corner brackets 140c of the rectangular frame (see FIG. 14) to guide the lifting tethers to the respective corners of the grabber devices. Thus, each tether extending from a respective spool around a respective pulley extends downward and connects to a grabber device, e.g., a corner of the grabber device. Mountings for the four pulleys 214 may be integrated into each corner bracket 140c of the rectangular frame.

[0091] In a specific embodiment of the present invention, the container-receiving space 137 (see FIG. 9a) for receiving a storage container when lifted by the grabber device is accommodated within the open-frame structure of the load handling apparatus, more specifically in the region of the first, second, and third modular sections (the third modular section supports a spool carrying the lifting tether). However, because vertically adjacent modular sections are connected together by their respective connection blocks via vertical connecting rods, it is necessary for the grabber device to be guided as it is lifted and lowered into and out of the container-receiving space to prevent it from fouling with the connection blocks. In a specific embodiment of the present invention, downwardly extending guides (not shown) are attached to the connection block 140c of the second modular section of the load handling apparatus, one at each corner of the rectangular frame, to guide the grabber device as it is lowered or raised into the container-receiving space. Each of the guides is shaped to include two vertical guide plates to accommodate the corners of the grabber device shown in FIG. 7.

[0092] Because the container lifting mechanism is configured to lift and lower storage containers that may weigh up to 40 kg, the connection elements extending between the corner brackets may be braced by one or more bracing elements 216 to strengthen the rectangular frame of the modular sections that support the spools that carry the lifting tethers. In the particular example shown in Figures 8a and 9a, two bracing elements 216 are shown bracing the connection elements extending between the corner brackets on opposite sides of the load handling apparatus. Opposite ends of the bracing elements are attached to the connection elements by connection blocks 218.

[0093] A plurality of rectangular frames 186 are assembled together in a vertical stack to provide different functional features of the load handling apparatus described above. Vertically adjacent rectangular frames are connected together by vertical connecting elements 188 to form an open frame structure 131 that supports different functional features of the load handling apparatus. FIGS. 10-12 show an example of assembling connecting blocks together by connecting rods to form rectangular frames of first, second, and fourth modular sections, respectively. Preferably, each of the connecting blocks (corner brackets) 140 at the corners of the plurality of rectangular frames are linked or connected together in the vertical stack by one or more vertical connecting elements or rods 188. A vertical connecting rod for connecting vertically adjacent rectangular frames is shown in FIG. 11. The vertical connecting rod is shown secured to the connecting block (corner bracket) at the corner of the rectangular frame. To link the connecting blocks together, the connecting block includes one or more openings or sockets 187 for receiving the ends of the connecting rod. Manufacturing the load handling apparatus involves inserting the ends of connecting rods into openings or sockets in the connecting blocks to join the connecting blocks together. To help reduce the weight of the load handling apparatus according to the present invention, the connecting rods are typically hollow, e.g., hollow pipes. A jig may be used to assemble the individual rectangular frames together, while the connections between the connecting blocks and / or corner brackets and the connecting elements are secured by suitable joints.

[0094] During operation of the load handling equipment on the grid structure, stresses experienced by the open frame structure are concentrated around the joints between the connection blocks and the connecting rods. If the connecting rods are not properly secured to the connection blocks, there is a risk that one or more of the connecting rods will become dislodged from its corresponding connection block, resulting in the ultimate failure of the rectangular frame to which it is associated and, in the worst case, the failure of the open frame structure. To ensure the structural integrity of the resulting open frame structure, the joints for securing the ends of the connecting rods to the connection blocks should be strong enough to prevent the ends of the connecting rods from becoming dislodged from the connection blocks, more specifically, from the sockets 187 in the connection blocks. Various joints may be used to secure the ends of the connecting rods to the connection blocks, which will largely depend on the materials used to fabricate the connection blocks and connecting rods. Various joints may include, but are not limited to, gluing or welding.

[0095] [joint] While one or more of the connection blocks of an open-frame structure may be topology-optimized to accommodate different loads or stresses experienced by the open-frame structure when operating as a load-handling device on a grid structure, the joints between the connection block 140 and the connection elements 184, 188, e.g., connecting rods, must also be strong enough to withstand the forces experienced when the load-handling device is operating on the grid structure. Such forces include forces tending to pull the connection rods out of their sockets 187 in the connection blocks, as well as bending and torsional forces when the connection elements are subjected to bending moments. Various techniques may be used to secure the connection blocks to the connection elements. These include the use of adhesives or glues, fasteners or welding, or any combination of these fastening methods. Using adhesives to secure the connection blocks to the connection elements is believed to be the most efficient and cost-effective method for assembling an open-framework structure comprising connection blocks linked together by multiple connection elements. However, because load handling equipment operable on a grid framework structure is subjected to many forces, including bending and torsional forces that result in bending moments at the joints between the connection blocks and the connection elements, the joints between the connection blocks and the connection elements must be strong enough to prevent the connection elements, which are typically in the form of rods, from becoming dislodged from the connection blocks. While various commercially available adhesives have the necessary adhesive strength to secure the connection elements to the connection blocks, the ability of the adhesive to provide a secure connection between the connection blocks and the connection elements depends largely on the surface contact area of ​​the adhesive between the connection block 140 and the connection elements 184, 188. The greater the adhesive surface contact area between the connection block and the connection elements, the greater the bond strength, as more of the adhesive can contribute to the bond strength between the connection block and the connection elements.

[0096] When the connecting element is a rod and the rod is inserted into an opening or socket 187 integrally formed in the connecting block 140, the adhesive strength between the rod and the inner-walled socket depends heavily on the spread of adhesive along the connecting end of the rod. Simply coating one end of the rod with adhesive and inserting the rod into the socket 187 of the connecting block 140 is problematic because the socket is a blind hole, leaving a buildup of adhesive at the socket entrance, which can cause excess adhesive to squeeze out of the socket entrance. This is unsightly and can cause other distortions in assemblies that include connecting blocks, such as in the open-frame structure described above. Second, coating the connecting end of the connecting element is unsuitable for assembling multiple connecting blocks with the connecting elements before adhesively securing or adhering the connecting blocks to the connecting elements. This is particularly true when multiple connecting blocks and connecting elements are assembled in a jig to ensure that the connecting blocks are precisely aligned with the rods in the assembly. This problem is exacerbated when the adhesive used to secure the connecting blocks to the connecting elements has a relatively short cure time after being applied. This problem is not limited to connecting blocks in the fabrication of open frame structures that support components that provide the functional features of the load handling apparatus described above; the problem can also exist when connecting any type of connecting block with connecting elements such as rods.

[0097] Therefore, there is a need for a joint capable of securing a connecting block to a rod that does not suffer from the above-mentioned drawbacks. In the present invention, an adhesive in fluid form is ideally spread along the connecting ends of the rods after or subsequent to the insertion of the connecting ends of the rods into the sockets of the connecting block. This allows multiple connecting blocks to be assembled with their respective rods before gluing or securing the rods to their respective connecting blocks, thereby enabling the use of a jig to control the precision or accuracy of the alignment of the connecting blocks with their respective rods. In one example of the present invention, the inner wall of the socket includes a groove extending around at least a portion of the inner wall of the socket to distribute adhesive along the connecting ends of the rods. The connecting block includes an inlet having an inlet opening on the exterior of the connecting block and in fluid communication with the groove for injecting adhesive into the groove, the groove configured to form a glue channel when the connecting end of the rod is inserted into the socket, such that when adhesive is injected into the inlet opening, the adhesive flows along the glue channel around the outer surface of the connecting end of the rod. Grooves of different shapes may be formed in the inner wall of the socket. An efficient way to distribute adhesive along the connecting end of the rod is to provide a continuous groove extending axially along at least a portion of the length of the socket to provide a continuous glue channel that is in fluid communication with the inlet opening when the connecting end of the rod is inserted into the socket.

[0098] One example of a continuous groove is a helical or spiral groove formed in the inner wall of the socket, resulting in a glue channel 220 having a helical or spiral shape. An example of a helical or spiral glue channel 220 extending axially along at least a portion of the longitudinal length of the socket is shown in FIG. 17. The spiral or helical glue channel 220 allows adhesive to be distributed or spread axially along the connecting end of the rod. Also shown in FIG. 17 is an inlet 222 for supplying adhesive to the spiral glue channel 220. The inlet is in fluid communication with the spiral glue channel 220 and includes an inlet passage 224 extending from an opening 226 in the inlet 222 to the spiral glue channel 220. The opening 226 is formed in at least one outer wall of the connecting block so that adhesive can be supplied to the glue channel from outside the connecting block. This has the advantage that adhesive can be supplied to the glue channels after the rods have been inserted into the sockets of the connecting blocks, which allows multiple connecting blocks to be assembled together in a jig before bonding the multiple connecting blocks to their respective connecting elements.

[0099] Different adhesives have different viscosities and curing times. To accommodate different adhesives having different viscosities and curing times injected into the glue channel, the flow rate of the adhesive through the glue channel is controlled. A flow rate that is too low may cause the adhesive to prematurely cure before it fills the glue channel, while a flow rate that is too high may cause the adhesive to leak out of the glue channel before it cures. To control the flow rate of the adhesive through the glue channel, the inlet passage 224 extending from the inlet opening 226 to the glue channel 220 is tapered or has diverging walls to create a Venturi effect so that a pressure difference exists between the pressure at the inlet opening 226 and the pressure at the inlet of the glue channel 220. By controlling the divergence of the inlet passage 224, this pressure difference can be controlled, and therefore the flow rate of the adhesive through the glue channel can be controlled. In the particular example shown in Figure 17, the inlet path 224 diverges such that the inlet path constricts as it approaches the inlet of the glue channel 220, resulting in a higher flow rate at the inlet of the glue channel. Although not shown in Figure 17, the connecting block may optionally include an outlet with an outlet path extending from an outlet opening on the exterior of the connecting block, allowing excess adhesive to exit the glue channel through the outlet opening. The adhesive exiting the outlet opening provides an indication that the adhesive has sufficiently filled the glue channel and the gluing process is complete.

[0100] However, according to the present invention, there are other examples in which adhesive is distributed along the connecting end of the rod when inserted into the socket to ensure good adhesion between the rod and the connecting block. In another example of a glue channel shown in Figures 18(a) and 18(b), the groove comprises a plurality of separate circular grooves spaced along the axial length of the socket, which provides a plurality of separate or separate circular glue channels 228 for distributing adhesive across the connecting end of the rod. To supply adhesive to each of the multiple circular glue channels, the inlet 322 comprises a plurality of inlet paths 330 branching from a single inlet opening 326, as shown in Figures 18(a) and 18(b). Each of the multiple inlet paths 330 feeds a respective circular glue channel of the multiple spaced circular glue channels 228. This allows adhesive to be supplied to each of the multiple circular glue channels 228 through a single injection of adhesive into the inlet opening 326 of the inlet 322. This is clearly shown in the schematic diagram of multiple circular glue channels in Figure 18(b). The number and spacing of the circular grooves, and therefore the circular glue channels 228, control the amount of glue deposited on the outer surface of the connecting end of the rod, between the inner wall of the socket and the connecting end of the rod, when the rod is inserted into the socket.

[0101] 18(a) and 18(b) also show an outlet 332 having an outlet path 334 common to the plurality of circular glue channels 228, in the sense that it is in fluid communication with the plurality of circular glue channels 228. As discussed above, the outlet 332 provides an indication that adhesive has filled the plurality of circular glue channels 228. The outlet path 334 is positioned such that adhesive flows through the plurality of glue channels 228 before exiting through an outlet opening 336. The outlet path 334 is shown as extending across the plurality of circular glue channels 228 to a single outlet opening 336 such that the outlet path 334 is shared among the plurality of circular glue channels 228.

[0102] While the use of lightweight materials such as plastics helps reduce the weight of the assembly of connecting blocks and connecting elements, such as the open-frame structure described above, the use of lightweight connecting elements also helps reduce the weight of the assembly. One example of a lightweight connecting element is a hollow rod. However, the use of hollow rods as connecting elements has several drawbacks. One major drawback is the risk that the hollow rod may collapse as a result of stress at the socket entrance. When the connection between the connecting block and the rod relies on the rod being inserted into a socket in the connecting block, there is a stress concentration area around the vicinity of the socket entrance. This is particularly the area at the socket entrance, which has a relatively sharp edge 232 as shown in FIG. 19 , where the shape of the socket wall changes abruptly. The bending moment experienced by the rod is concentrated around the area around the socket entrance, particularly at the edge 232 of the socket 187, with the risk of the socket edge impinging against the wall of the rod 184. Without internal support, stresses concentrated at the edges 232 of the socket 187 could cause the rod 184 to bend and, in the worst case, risk collapsing.

[0103] To alleviate this problem, as shown in FIG. 19 , an insert 234 is provided in the socket 187 that is receivable in the hollow portion of the rod 184 to provide internal support when the connecting end of the rod is inserted into the socket of the connecting block. The insert shown in FIG. 19 extends axially along at least a portion of the longitudinal length of the socket, with an axis XX that is concentric with the longitudinal axis of the socket. Introducing the insert 234 into the socket 187 of the connecting block also introduces additional manufacturing complications due to the inclusion of glue channels in the socket. The use of additive manufacturing or 3D printing in the fabrication of connecting blocks offers the opportunity to integrally form complex shapes within the interior of the connecting block.

[0104] To provide a secure bond between the rod and the connecting block, glue channels are formed around the inner wall of the socket and the outer surface of the insert. In certain embodiments of the present invention, as shown in the example of the present invention shown in FIG. 19, a groove is formed around the inner wall of the socket to form a first glue channel 420a when the rod is inserted into the socket, and a groove is formed around the outer periphery or surface of the insert to form a second glue channel 420b when the rod is inserted into the socket. Due to the location of the first groove on the inner wall of the socket and the second groove on the outer surface of the insert, the first glue channel 420a is shown in FIG. 19 as facing the second glue channel 420b. Thus, both the outer and inner surfaces of the connecting end of the rod are glued to the inner wall of the socket and the outer surface of the insert, respectively (see FIG. 19). A vent 424 may be incorporated into the insert to prevent air from accumulating inside the rod when it is inserted into the socket 187. Vent 424 is a through hole that extends from the insert to the exterior of the connecting block to allow air to escape from the interior of the rod when the rod is inserted into the socket.

[0105] To supply adhesive to the first and second glue channels 420a, 420b from a single injection point when the socket 187 includes the insert 234, in one example of the present invention, the inlet path from the inlet opening 426 on the exterior of the connecting block includes multiple inlet paths 430a, 430b branching from the single inlet opening 426 such that the longitudinal axis AA of the second glue channel 420b is concentric with the longitudinal axis of the first glue channel 420a. An example of providing the first and second glue channels 420a, 420b is shown in Figures 20(a) and 20(b), which show a spiral-shaped glue channel arrangement for the first and second glue channels 430a, 430b. Each of the first and second glue channels can be supplied with adhesive by first and second inlets, each supplied from a separate inlet opening. Alternatively, the first and second glue channels 420a, 420b may be fed from a single inlet opening 426 that branches into multiple inlet paths 430a, 430b, each feeding a respective first and second glue channel 420a, 420b. The inlet shown in Figures 20(a) and 20(b) comprises first and second inlet paths 430a, 430b in fluid communication with the first and second glue channels 420a, 420b, which feed from a single or common inlet opening 426 external to the connecting block. Each of the first and second inlet paths 430a, 430b branches from the inlet opening 426 into a respective first and second glue channel 420a, 420b. Each of the first and second glue channels 420a, 420b may have a separate outlet to provide an indication that their respective first and second glue channels are filled with adhesive. Alternatively, as described above, a common outlet may be provided for both the first and second glue channels.

[0106] 21(a) and 21(b) show another example of providing first and second glue channels for supplying adhesive to the inner wall of the socket and the outer surface of the insert, respectively. In the glue channel arrangement in the example shown in FIGS. 21(a) and 21(b), the glue channels supplying adhesive to the inner wall of the socket and the outer surface of the insert are based on a combination of the spiral type 520a and separate circular ring 520b described above with reference to FIGS. 17 and 18(a) and 18(b). In the particular example shown in FIGS. 21(a) and 21(b), a groove formed in the inner wall of the socket cooperates with the outer surface of the connecting end of the rod to form a separate circular glue channel 520a, and a groove on the outer surface of the insert cooperates with the inner surface of the connecting rod to form a spiral-shaped glue channel 520b. Having a combination of a separate circular glue channel on the outer surface of the rod and a spiral glue channel on the inner surface of the rod allows both types of glue channels to be supplied with a single injection of adhesive into the inlet 522. To accommodate supplying adhesive to glue channels of different shapes, the inlet 522 includes multiple inlet paths 530a branching to supply adhesive to the separate circular glue channels of the first glue channel 520a on the exterior of the rod, and a single inlet path 530b to supply adhesive to the spiral glue channel of the second glue channel 520b on the interior of the rod, as shown in FIG. 21a. However, different arrangements of glue channels for supplying adhesive to the exterior surface of the rod and the interior surface of the rod are applicable in the present invention, including the different arrangements of glue channels described above with reference to FIGS. 17 and 18(a and b). Also shown in FIGS. 21a and 21b are outlets 532 in fluid communication with the first and second glue channels 520a, 520b to provide an indication that the respective first and second glue channels 520a, 520b are filled.

[0107] While specific example glue channels are formed by incorporating grooves in the interior wall of the socket, as shown in Figures 17-21(a and b), the glue channels can also be formed by providing grooves in the connecting end of the rod so that when the connecting end of the rod is inserted into the socket, adhesive can be injected into the glue channel from an inlet having an inlet opening that is external to the connecting block and in fluid communication with the glue channel. The inlet channel is positioned in the connecting block to direct the adhesive to one or more grooves in the connecting end of the rod. As the adhesive travels around the grooves in the connecting end of the rod, the adhesive is distributed along the connecting end of the rod inserted into the socket. Upon curing, the adhesive forms a joint between the interior wall of the socket and the connecting end of the rod.

[0108] An advantage of injecting adhesive through an external inlet opening of the connecting block is the ability to assemble multiple connecting blocks and connecting rods in a jig to ensure the assembly is precisely positioned before the adhesive is injected into the inlet opening. Having different shaped glue channels inside the socket for receiving the connecting end of the rod ensures that the adhesive spreads along the connecting end of the rod to provide good adhesion between the connecting block and the rod. Different shaped glue channels inside the socket are possible because the connecting blocks can be manufactured by additive manufacturing or 3D printing, which allows complex shapes to be built into the connecting block.

Claims

1. 1. A load handling apparatus for lifting and moving one or more stackable containers in a storage and retrieval system, the storage and retrieval system comprising a grid structure comprising a plurality of grid members, the grid members comprising a first set of grid members and a second set of grid members, the second set of grid members being substantially perpendicular to the first set of grid members, whereby the plurality of grid members are arranged in a grid pattern for guiding movement of the load handling apparatus on the grid structure, the load handling apparatus comprising a plurality of modular sections arranged in vertical stacks, the plurality of modular sections comprising: a) a container lifting mechanism comprising a grabber device configured to releasably grasp a container and a drive mechanism configured to raise and lower said grabber device; b) a wheel assembly comprising: a first set of wheels for engaging said first set of grid members to guide movement of said load handling apparatus in a first direction; and a second set of wheels for engaging said second set of grid members to guide movement of said load handling apparatus in a second direction, wherein said second direction is transverse to said first direction; c) a wheel positioning mechanism configured to selectively lower or raise the first set of wheels or the second set of wheels to engage or disengage the first set of grid members or the second set of grid members; d) an electrical component including a processor for controlling the container lifting mechanism and the wheel positioning mechanism; Equipped with 10. The load handling apparatus of claim 9, wherein each of the plurality of modular sections further comprises at least four connection blocks, each of the at least four connection blocks connected to two other connection blocks in a single modular section by one or more substantially horizontal connection elements to form a rectangular frame, and wherein the at least four connection blocks of vertically adjacent modular sections are connectable in the vertical stack by one or more substantially vertical connection elements to form an open frame structure comprising a plurality of the rectangular frames, the open frame structure being configured to support the container lifting mechanism, the wheel assembly, the wheel positioning mechanism, and the electrical components.

2. 2. The cargo handling apparatus of claim 1, wherein the at least four connecting blocks comprise four corner brackets such that each corner bracket of the four corner brackets is connected to two other corner brackets in a single modular frame to form the rectangular frame.

3. 3. Load handling apparatus according to claim 1 or 2, wherein one or more of the horizontal connecting elements and / or the vertical connecting elements comprise connecting rods or tubes.

4. 4. A load handling apparatus according to claim 3, wherein one or more of the at least four connection blocks comprises a socket for receiving an end of the connecting rod or tube.

5. 5. The load handling device of claim 4, wherein the socket has a substantially cylindrical inner wall having a groove extending continuously around at least a portion of the cylindrical inner wall of the socket for distributing adhesive axially along the receiving end of the rod, the groove being configured to form a glue channel when the receiving end of the connecting rod is inserted into the socket.

6. 6. The cargo handling device of claim 5, wherein the one or more of the at least four connection blocks comprises one or more injection points in fluid communication with the groove for injecting adhesive into the glue channel.

7. 7. A load handling apparatus according to any preceding claim, wherein the rectangular frame of one or more of the plurality of modular sections is braced by one or more bracing elements extending between opposing horizontal connecting elements.

8. 8. A load handling apparatus according to any one of claims 1 to 7, wherein the one or more vertical connection elements extend vertically through one or more of the at least four connection blocks of vertically adjacent rectangular frames in the vertical stack.

9. A load handling apparatus according to any preceding claim, wherein one or more of the at least four connecting blocks of one or more of the plurality of modular sections are formed from a polymer.

10. A load handling apparatus according to any preceding claim, wherein the open frame structure defines a volume for accommodating a container receiving space.

11. 11. A load handling apparatus according to any preceding claim, wherein one or more of the at least four connecting blocks of the one or more of the plurality of modular sections comprises one or more mountings for pulleys.

12. 12. A load handling apparatus according to any preceding claim, wherein one or more of the at least four connecting blocks of the one or more of the plurality of modular sections comprises one or more mountings for a motor.

13. 13. A load handling apparatus according to any one of claims 1 to 12, wherein one or more of the at least four connecting blocks of the one or more of the plurality of modular sections comprises at least a part of the container lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or the electrical component.

14. 14. The load handling apparatus of claim 13, wherein at least a portion of the container lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or the electrical components are integrally formed with one or more of the at least four connecting blocks of one or more of the plurality of modular sections.

15. 15. The load handling apparatus of claim 14, wherein each wheel of the wheel assembly is mounted on a wheel mount.

16. 16. Load handling apparatus according to claim 15, wherein the wheel mounts are integrally formed with connecting blocks of a given modular section.

17. 17. Load handling apparatus according to claim 15 or 16, wherein the connecting block of a given modular section comprises a first wheel mount for a wheel of the first set of wheels and a second wheel mount for a wheel of the second set of wheels.

18. The first and second wheel mounts include a plurality of bosses along edges of the first and second wheel mounts, each of the plurality of bosses of the first and second wheel mounts including an opening axially aligned along a wheel positioning axis, the wheel positioning axis being an axis along which the respective first set of wheels or the respective second set of wheels is raised and lowered, and the plurality of bosses of the first and second wheel mounts are aligned with the plurality of bosses of the first and second wheel mounts.

18. The load handling apparatus of claim 17, wherein bosses are interlocking and spaced apart such that the openings in each of the interlocking bosses of the first wheel mount and the second wheel mount are axially aligned along the wheel positioning axis for receiving the vertical connecting element therethrough, and wherein the spacing between the bosses of the first wheel mount and the second wheel mount is sufficiently spaced apart to allow the first wheel mount to move independently of the second wheel mount along the wheel positioning axis.

19. 19. Load handling apparatus according to any one of the preceding claims, wherein the wheel positioning mechanism comprises a cam mechanism and one or more of the at least four connecting blocks of one or more of the plurality of modular sections comprises at least a portion of the cam mechanism.

20. 20. The load handling apparatus of claim 19, wherein said at least a portion of said cam mechanism is integrally formed with said one or more of said at least four connecting blocks of one or more of said plurality of modular sections.

21. The container lifting mechanism includes: a) a first set of spools and a second set of spools, wherein each spool of the first set of spools and the second set of spools carries a lifting tether having a first end secured to a container gripping assembly and a second end secured to the spool; b) a rotatable shaft, wherein the first set of spools and / or the second set of spools are mounted on the rotatable shaft such that the rotatable shaft is common to the first set of spools and / or the second set of spools; c) the drive mechanism comprising a drive pulley attached to the rotatable shaft common to the first set of spools and / or the second set of spools such that rotation of the rotatable shaft by the drive pulley drives rotation of the first set of spools and / or the second set of spools; 21. A load handling apparatus according to any preceding claim, comprising:

22. 22. Load handling apparatus according to claim 21, wherein the rotatable shaft is attached to the one or more horizontal connection elements connecting two adjacent connection blocks.

23. 23. A load handling apparatus as claimed in any one of the preceding claims, wherein any one of the container lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or the electrical components is shared between two or more of the plurality of modular sections.

24. 24. Load handling apparatus according to any one of claims 1 to 23, wherein a plurality of vertically adjacent rectangular frames define a volume for accommodating at least a portion of the container lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or the electrical components.

25. 25. A cargo handling apparatus as claimed in any one of claims 1 to 24, wherein the plurality of modular sections, in ascending order of height of the cargo handling apparatus, comprise a first modular section, a second modular section, a third modular section and a fourth modular section, the first modular section being at the bottom of the cargo handling apparatus and the fourth modular section being at the top of the cargo handling apparatus.

26. 26. Load handling apparatus according to claim 25, wherein the first modular section comprises the wheel assembly.

27. 27. Load handling apparatus according to claim 25 or 26, wherein the fourth modular section comprises one or more cradles for supporting the electrical components.

28. 28. Load handling apparatus according to claim 27, wherein the one or more cradles are attached to one or more of the horizontal connection elements connecting two adjacent connection blocks of the fourth modular section.

29. Load handling apparatus according to any preceding claim, wherein one or more of the connecting blocks of one or more of the plurality of rectangular frames are integrally formed as a single unit.

30. 1. A method of constructing a load handling apparatus, comprising the steps of: i) forming a rectangular frame by connecting at least four connecting blocks together by one or more horizontal connecting elements; ii) linking a plurality of rectangular frames together in a vertical stack by connecting the connection blocks of vertically adjacent rectangular frames by one or more vertical connection elements to form an open frame structure; The open frame structure comprises: a) a container lifting mechanism comprising a grabber device configured to releasably grasp a container and a drive mechanism configured to raise and lower said grabber device; b) a wheel assembly arranged to support a vehicle body, said wheel assembly comprising: a first set of wheels for engaging a first set of grid members to guide movement of said load handling apparatus in a first direction; and a second set of wheels for engaging a second set of grid members to guide movement of said load handling apparatus in a second direction, said second direction being transverse to said first direction; and each wheel of said first set of wheels and said second set of wheels being mounted on a wheel mount; c) a wheel positioning mechanism configured to selectively lower or raise the first set of wheels or the second set of wheels to engage or disengage the first set of grid members or the second set of grid members; d) an electrical component including a processor for controlling said lifting mechanism and said wheel positioning mechanism; Supporting,method.

31. 31. The method of claim 30, wherein the open frame structure is formed by inserting one or more of a plurality of the horizontal connecting elements and / or the vertical connecting elements into openings in one or more of the at least four connecting blocks.

32. 32. The method of claim 30 or 31, further comprising the step of attaching the container lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism, and / or at least a portion of the electrical components to the open frame structure.

33. 33. The method according to any one of claims 30 to 32, further comprising the step of integrally forming at least a part of the container lifting mechanism, and / or the wheel assembly, and / or the wheel positioning mechanism from one or more of the at least four connecting blocks of the open frame structure.

34. 34. The method of any one of claims 30 to 33, further comprising additive manufacturing or 3D printing one or more of the at least four connecting blocks of one or more of the plurality of rectangular frames of the open frame structure.

35. 35. The method of any one of claims 30 to 34, further comprising assembling one or more of the plurality of rectangular frames with a jig such that the at least four connecting blocks are connected to their respective horizontal connecting elements.

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