Apparatus and method for charging a load handling device

Abstract

To provide an apparatus and method for charging a load handling device.SOLUTION: In a load handling device (30) for lifting and moving containers stacked in a storage system, an electrical charge point (80) is disposed on a vehicle body (32) housing a driving mechanism operatively arranged for moving the load handling device, and comprises a charge collector (86) connectable to a charge head (84) of a charge station under action of a magnet. The load handling device further comprises: a lifting device comprising a lifting drive assembly and a grab configured to receive the container from a stack and lift the container into a space. The driving mechanism and the lifting drive assembly are powered by a rechargeable power source electrically coupled to the electrical charge point (80) arranged on the vehicle body (32) for electrically coupling to the charge head (84) of the charge station (82) in use.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to the field of load handling devices for handling storage containers or receptacles in a storage system comprising a grid of stacked containers, and more particularly to an apparatus and method for charging the load handling devices. [Background technology]

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

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

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

[0005] The top level of the lattice frame structure 14 includes rails 22 arranged in a lattice pattern across the top of the stacks 12. Referring further to FIG. 3 , the rails 22 support a plurality of load handling devices 30. A first set 22a of parallel rails 22 guides movement of the robotic load handling devices 30 in a first direction (e.g., the X direction) across the top of the lattice frame structure 14, and a second set 22b of parallel rails 22 is arranged perpendicular to the first set 22a and guides movement of the load handling devices 30 in a second direction (e.g., the Y direction) perpendicular to the first direction. In this manner, the rails 22 enable movement of the robotic load handling devices 30 laterally in two dimensions, in the horizontal XY plane, so that the load handling devices 30 can be moved to a position above any of the stacks 12.

[0006] A known load handling device 30, shown in FIGS. 4 and 5 , is described in PCT Patent Publication No. WO 2015 / 019055 (Ocado), incorporated herein by reference, comprising a vehicle body 32, with each load handling device 30 covering only one grid space of a lattice framework structure 14. Here, the load handling device 30 comprises a wheel assembly comprising a first set of wheels 34, consisting of a pair of wheels 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 device in a first direction, and a second set of wheels 36, consisting of a pair of wheels 36 on each side of the vehicle 32, for engaging a second set of rails or tracks to guide movement of the device in a second direction. Each of the set wheels is driven to enable movement of the vehicle in the X and Y directions along the rails. One or both sets of wheels can be moved vertically to lift each set of wheels from its respective rail, thereby allowing the vehicle to move in a desired direction.

[0007] The load handling device 30 includes a lifting device or crane mechanism for lifting a storage container from above. The crane mechanism includes a winch tether or cable 38 wound on a spool or reel (not shown) and a gripping device 39. The lifting device includes a set of vertically extending lifting tethers 38 connected near or to the four corners of a lifting frame 39, alternatively known as gripping devices (one tether near each of the four corners of the gripping device) for releasably connecting to the storage container 10. The gripping device 39 is configured to releasably grasp the top of a storage container to lift it from a stack of containers in a storage system of the type shown in Figures 1-2.

[0008] The wheels 34, 36 are positioned at the bottom around a cavity or recess known as a container receiving recess 40. The recess is sized to accommodate the container 10 when it is lifted by the crane mechanism, as shown in Figures 5(a and b). In the recess, when the container is fully lifted from the lower rail, the vehicle can move laterally to a different position. Upon reaching the target location, e.g., 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 removed from the gripping device.

[0009] Although not shown in FIGS. 1-3 , the load handling device 30 is powered during operation by a variety of rechargeable batteries. Examples of rechargeable batteries include lithium-ion batteries, nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion polymer batteries, thin-film batteries, and smart battery carbon foam-based lead batteries. The batteries are recharged while the load handling device 30 is operating on the lattice framework structure 14 by a charging station 50, shown in FIG. 6 . The charging station 50 typically has an L-shaped structure that is secured proximate to the lattice framework structure and extends across a nominal grid cell at the edge of the lattice structure. The charging station 50 includes a charging head 52 with charging contacts fixed in position relative to the charging station 50. The charging head 52 is attached to one arm 54 of the L-shaped structure so that the charging head 52 is suspended across at least two grid spaces of the lattice framework. The load handling device may be charged by being commanded to move to the grid cell in which the charging head 52 is located. When the load handling device is moved into the grid cell, contact is made between the charging contact pads on the top surface of the load handling device and the charging contacts of the charging head, and charge is imparted from the charging contacts to the load handling device through the charging contact pads located on the top surface of the load handling device.

[0010] However, charging stations present many challenges. In particular, as the robotic load handling device moves into the charging station, a clamping force exists between the charging contacts and the robotic load handling device. However, the magnitude of this force can cause problems over time. For example, repeated entry of the robotic load handling device into the lattice cells in which the charging station is located can cause fatigue of the charging station, necessitating maintenance or replacement of the charging head and support structure. Furthermore, vibrations of the lattice framework structure caused by movement of the robotic load handling device can adversely affect alignment between the charging contacts of the charging station and the robotic load handling device. Furthermore, damage, wear, and material creep of the lattice cells can cause alignment issues between the charging contacts and the charging pad contacts, adversely affecting the ability of the robotic load handling device to contact the charging contacts. Similarly, tolerances in the manufacture of both the lattice framework structure and the charging station, and / or slight variations in the installation alignment of the lattice framework structure relative to the charging station, and / or thermal expansion of the lattice framework structure relative to the charging station can also cause alignment issues that adversely affect the ability of the robotic load handling device to contact the charging contacts. Furthermore, the charging contacts wear over time and therefore require periodic inspection or repair. However, maintenance of the charging contacts requires human intervention on top of the lattice framework structure, which can only be performed when the robotic load handling devices on top of the lattice framework structure are in a "safe mode" that renders them inoperable. Downtime as a result of the load handling devices being idle leads to loss of production throughout the system.

[0011] WO 2019 / 215221 (Ocado Innovation Limited) addresses this issue by providing a charging station in which a charging head is pulled toward a charging pad on the top surface of a load handling device. The charging unit 56 (see FIGS. 7a and 7b) includes a plurality of cross-sectional sections 58, 60 arranged to interface with a hoist element 70 (see FIG. 8) of the load handling device 30, and a power transmission component 62 arranged to transmit power to the load handling device when the hoist element 70 engages the plurality of cross-sectional sections 58, 60. FIG. 8 shows the hoist element 70 arranged on top of the load handling device for use in manual movement of the load handling device 30. The hoist element 70 includes a notch below its bulbous head, which creates an underside 72. The hoist element 70 is designed to allow attachment of a hoist to lift the load handling device 30 from the grid cell. The power transfer component 62 is typically constructed from copper and is biased outward by a resilient member, e.g., a spring, to reduce the impact of the power transfer unit 62 contacting the charging pad 74 on the top surface 76 of the handling device 30. In addition to the power transfer unit 62, the cartridge 56 includes a plurality of charging contacts 63 on its underside. Similar to the power transfer unit 62, the plurality of charging contacts 63 are biased outward by a resilient member, e.g., a spring, to reduce the impact of the charging contacts 63 contacting the charging pad 74 on the top surface 76 of the handling device 30. In contrast to the power transfer unit 62, the additional charging contacts may be for the purpose of preventing arcing between the power transfer units or for data transfer during charging.

[0012] The multiple cross-sectional sections 58, 60 and power transfer unit 62 are positioned within the moveable cartridge 56 such that contact between the hoist element 70 and the multiple cross-sectional sections 58, 60 moves the cartridge 56 toward the load handling device 30. This allows for control of the amount of clamping force on the cartridge 56, and in particular, the clamping force on the power transfer unit 62 having a charging pad 74 on the top surface of the load handling device. Together with the resiliently biased power transfer unit 62 and / or the multiple resiliently biased charging contacts 74, damage / wear to the cartridge and / or the top surface of the robotic load handling device is minimized.

[0013] However, the increased number of cartridge components taught by WO 2019 / 215221 (Ocado Innovation Limited), such as multiple contoured cross sections, not only increases the complexity of the charging station but also makes the charging station expensive to service if any one of the components requires repair or replacement. Furthermore, the need to suspend the cartridge above the load handling device presents potential alignment issues between the cartridge's charging contacts and the load handling device's hoisting elements. In extreme cases, this could lead to improper seating of the hoisting elements relative to the cross section of the charging unit, resulting in improper electrical coupling between the charging contacts on the top surface of the load handling device and the charging station's cartridge, resulting in improper or prolonged charging of the battery. Another consideration, in which misalignment of a robotic load handling device with a charging station could adversely affect the proper operation of the robotic load handling device, is the risk of arcing between the charging station's power transfer components and the load handling device's charging contacts. Although the charging pad is resiliently mounted, there is still insufficient clamping force between the charging head and the charging contacts, which can cause potential arcing between their corresponding contact surfaces and ultimately damage the contact surfaces.

[0014] In WO 2019 / 238702 (Autostore Technology AS), a charge-receiving element for charging a battery is attached to the underside of a container vehicle or a load handling device and is positioned to electrically couple with a charge-providing element of a charging station located within a single grid cell at a level below the rails on a grid framework structure. During operation, the container vehicle is moved to a position above the charging station so that the charge-receiving element on the underside of the container vehicle is directly above the charge-supplying element of the charging station within the grid cell, more specifically, so that their corresponding contact surfaces directly face each other. Electrical contact or coupling is achieved by vertically lowering the container vehicle toward the rail grid, for example, by vertically displacing a set of wheels on the container vehicle, so that the corresponding contact surfaces of the charge-receiving element and the charge-supplying element engage. Lowering the container vehicle toward the rail grid presses the contact surface of the charge-receiving element into engagement with the contact surface of the charge-supplying element of the charging station. The charge-receiving element or charge-supplying element may be connected to a resilient assembly to vertically bias the charge-receiving element or charge-supplying element. While integrating a charging station within a single grid cell of the grid framework and at a level below the rails of the rail grid, it allows the charging station to be placed anywhere on the rail grid without interfering with the movement of the container vehicle. WO 2019 / 238702 (Autostore Technology AS) is very limited to container vehicles equipped with crane devices having cantilever arms extending laterally from the top of the vehicle to accommodate a container receiving space. That is, the container is accommodated under the cantilever arms and held above the rail level. Similarly, the vehicle must be heavy enough to counterbalance the weight of the container and to stabilize during the lifting process. Without the cantilever arms, the load handling device would not be able to accommodate the container within the vehicle body. As a result, a container vehicle including a container receiving space has a footprint extending across at least two grid cells.

[0015] Therefore, a charging station needs: i) having a footprint that does not occupy more than a single lattice space or cell of the lattice framework structure; ii) easier to manufacture, containing fewer moving parts; iii) capable of accommodating load handling devices of different heights; iv) It does not suffer from alignment problems between the contact pads of the charging head and the charge receiving pads of the load handling device.

[0016] It is against this background that the present invention is conceived.

[0017] This application claims priority from UK Patent Application Nos. GB2001108.6, filed January 27, 2020, and GB2010702.5, filed July 10, 2020, the contents of which are incorporated herein by reference. Summary of the Invention

[0018] Applicant has alleviated the above problems by providing a load handling device for lifting and moving stacked containers within a storage system comprising a lattice framework structure with pathways arranged in a lattice pattern above the stack of containers, the load handling device comprising: a body housing a drive mechanism operatively arranged to move the load handling device on the lattice framework; a lifting drive assembly configured in use to releasably grip a container and lift the container from the stack into the container receiving space, and a lifting device comprising a gripping device, wherein the drive mechanism and lifting drive assembly are powered by a rechargeable power source electrically coupled to a charging point located on the vehicle body for electrically coupling to a charging head of a charging station in use; The charging point is characterized in that it comprises a charge collector which can be connected to a charging head of a charging station under the action of a magnet.

[0019] For purposes of this patent specification, a storage system for storing items, retrieving, processing, and / or fulfilling orders, where access to such items is provided by fully or semi-automated retrieval by load handling devices, is referred to as a lattice framework structure or "hive." The lattice framework structure or "hive" provides a path in the form of a grid layout for movement of load handling devices to perform operations across various locations within the "hive." Preferably, the rechargeable power source may be a battery or a capacitor. The charging station is connected to a suitable power charger, preferably a DC power charger. For example, the power charger includes a rectifier that converts AC current to DC current. For purposes of this patent specification, the phrase "under the influence of a magnet" encompasses both magnetic attraction and / or magnetic repulsion through the use of either permanent magnets or electromagnets.

[0020] Optionally, the body houses a lifting device comprising a lifting drive assembly and a gripping device, whereby the gripping device is configured, in use, to releasably grip a container and lift the container from the stack within the framework into the container receiving space. The container receiving space may comprise a cavity or recess located within the body of the body, as described in WO 2015 / 019055 (Ocado Innovation Limited). Alternatively, the body of the load handling device may comprise a cantilever as taught in WO 2019 / 238702 (Autostore Technology AS), in which case the container receiving space is located below the cantilever of the load handling device. In this case, the gripping device is raised by the cantilever, and the gripping device can engage the container and lift it from the stack into the container receiving space below the cantilever.

[0021] Optionally, the vehicle body houses a rechargeable power source. Optionally, the path includes a plurality of rails or tracks. More particularly, a first set of tracks extends in a first direction and a second set of tracks extends in a second direction, the first direction being substantially perpendicular to the second direction such that the plurality of rails or tracks are arranged in a grid pattern.

[0022] The charging point comprises a charge collector configured to be physically connectable to a charging head of the charging station under the action of a magnet. Preferably, the charge collector comprises at least two charge receiving pads arranged to be connectable to at least two charge supply pads of the charging head. According to the invention, the at least two charge receiving pads are arranged to be pushed or pulled against each of the at least two charge supply pads of the charging head by magnetic attraction. In one aspect of the invention, the charging head is arranged to contact the charge collector under the action of an electromagnet, i.e., the electromagnet is energized to provide the magnetic attraction. In another aspect of the invention, the charging head is arranged to contact the charge collector under the action of one or more permanent magnets.

[0023] Conversely, the at least two charge receiving pads are positioned so as to be separated from the at least two respective charge supply pads of the charging head by magnetic repulsion. As taught in PCT / EP2019 / 061808 (Ocado Innovation Limited), using magnets to guide the charge receiving pads and the respective charge supply pads together eliminates alignment issues that can arise when physically aligning the pads together, i.e., through the use of a charging head including a movable cartridge with a cross-sectional section positioned to guide and interface with a hoisting element. Furthermore, the use of magnets to connect the charge collector to the charging head allows for high contact pressure to be established between the charge collector and the charging head, thereby contributing to low electrical contact resistance by increasing the surface contact area between the charging head and the charge collector. This helps limit deterioration of the contact pad contact surface. Preferably, the charge collector includes one or more permanent magnets. More preferably, the one or more permanent magnets are rare earth magnets. The high magnetic attraction provided by the rare earth magnets contributes to low electrical contact resistance between the at least two charge receiving pads and the at least two charge supply pads. An example of a rare earth magnet that has superior tensile strength compared to ferrite magnets is a neodymium magnet.

[0024] In one aspect of the present invention, the charge collector is movable relative to the vehicle body to connect to the charging head of the charging station under the action of a magnet. Preferably, the charge collector comprises a telescopic element attached to the vehicle body so as to be extendable from and retractable within the outer housing. More preferably, the charge collector comprises an inner housing receivable within the outer housing, the inner housing being telescopically movable relative to the outer housing. A charge receiving pad of the charge collector is attached to the inner housing. Preferably, the charge collector is extendable to contact the charging head under magnetic attraction and retractable within the outer housing under magnetic repulsion. The magnetic repulsion is provided by incorporating one or more magnets within the charging head to repel one or more magnets within the charge collector. Optionally, the charge collector is retractable within the outer housing by a resilient member. Optionally, the resilient member is a spring. Such a configuration eliminates the need to apply a magnetic repulsion force to retract the charge collector within the outer housing when detached from the charging head, and thus the charge collector is only extendable to connect to the charging head by magnetic attraction.

[0025] Preferably, the charging point of the present invention is mounted on the outer surface of at least one wall of the vehicle body. More preferably, the wall is a side wall of the vehicle body. This allows the load handling device to dock with the charging station and mate the charge collector with the charging head under the action of magnetic attraction. For example, the load handling device can be operated to dock with the charging station so that the magnetic attraction between the charge collector and the charging head allows the charge collector to be drawn toward and contact the charging head of the charging station, more specifically, so that at least two charge receiving pads of the charge collector mate with at least two corresponding charge supplying pads of the charging head. Preferably, the charge collector is extendable from and retractable within the outer housing so that it is drawn toward the charging head under the influence of magnetic attraction and pushed away from the charging head under the influence of magnetic repulsion. More preferably, the charge collector includes a telescopic element with an inner housing receivable within the outer housing.

[0026] Preferably, the vehicle body includes a skirt body having a first pair of opposing sidewalls and a second pair of opposing sidewalls, and the charging point is attached to the bottom edge of at least one of the first and / or second pairs of opposing sidewalls. This provides flexibility for attaching a charge collector to the bottom edge of the load handling device to cooperate with a charging head attached to a grid rail or track. Engagement with the charging head occurs when the load handling device is positioned and parked over the rail- or track-mounted charging head so that the charge collector is drawn toward the charging head under the influence of magnetic attraction, i.e., the charge collector is pulled down toward the charging head by magnetic attraction. By attaching the charge collector to the bottom edge of the vehicle body skirt to engage with the charging head attached to the rail or track on the grid framework structure, a container receiving space is maintained for accommodating a container from above.

[0027] The present invention also provides a storage system, i) a grid framework supporting a path arranged in a grid pattern comprising a plurality of grid spaces or grid cells; ii) a load handling device for lifting and moving containers stacked within a lattice framework structure, a) a body housing a drive mechanism operatively arranged to move a load handling device on a lattice framework; b) a lifting device comprising a lifting drive assembly and a gripping device configured, in use, to releasably grip a container and lift the container from the stack into the container receiving space; a load handling device, wherein the drive mechanism and lift drive assembly are powered by a rechargeable power source electrically coupled to a charging point located on the vehicle body that includes a charge collector; iii) a charging station comprising a charging head electrically coupled to the power charger; The charging head is characterized in that it is connectable with the charge collector for charging the rechargeable power supply of the load handling device under the influence of a magnet.

[0028] Optionally, the path comprises a plurality of rails or tracks, more preferably the path comprises a first set of parallel rails or tracks extending in a first direction and a second set of parallel rails or tracks extending in a second direction, the first direction being substantially perpendicular to the second direction such that the first set of parallel rails or tracks and the second set of parallel rails or tracks are arranged in a grid pattern. Optionally, the car body houses a lifting device comprising a lifting drive assembly and a gripping device, whereby the gripping device is configured, in use, to releasably grip a container and lift it from a stack in the framework into the container receiving space. Optionally, the gripping device is suspended from the body of the load handling device by four tethers. If the container receiving space is a cavity or recess in the car body, this may be from within the car body, or alternatively, if the car body includes a cantilever, the gripping device is suspended from the cantilever of the car body. Preferably, the tethers are in the form of a tape, band, or rope. Optionally, the car body houses a rechargeable power source.

[0029] In one aspect of the present invention, the charge collector and / or charging head of the charging station include one or more magnets arranged to electrically couple to each other under the action of magnetic attraction and / or to electrically decouple from each other under the action of magnetic repulsion. Preferably, the one or more magnets are permanent magnets. Preferably, either the charge collector or the charging head, or both, are movable so as to electrically couple to each other under the action of the magnets. Thus, the charge collector and the charging head are arranged to be attracted to each other under the action of magnetic attraction. More specifically, the charge receiving pad of the charge collector and the charge supply pad of the charging head are arranged to be attracted to each other under the action of magnetic attraction.

[0030] In a charging operation, a vehicle-mounted charging point is presented to the charging station's charging head, and the load handling device is operated so that the charge collector's charge-receiving pad is aligned with the charge-delivery pad of the charging head. Under the action of magnetic attraction, the charge collector and / or charging head are drawn into contact with each other. To stop the charging operation, the load handling device is moved so that one or more magnets in the charge collector and / or charging head are positioned to repel each other, and either the charge collector or the charging head, depending on which one is movable, is pushed and retracted within its outer housing. The magnets are positioned in the charge collector and charging head to attract or repel each other depending on the position of the charge collector relative to the charging head; i.e., different poles of the magnets face each other, resulting in magnetic attraction, and like poles face each other, resulting in magnetic repulsion. To disconnect the charge collector from the charging head, the load handling device is instructed to move one or more magnets in the charge collector so that they repel one or more magnets in the charging head, i.e., so that the magnetic poles of the magnets face each other, retracting either the charge collector or the charging head. Once safely stored, the load handling device can continue to move on the lattice framework structure. Alternatively, the charging head is biased to retract into its outer housing by a resilient member, for example a spring.

[0031] Preferably, the charging head is mounted to at least one of a plurality of rails or tracks on the lattice framework structure to enable the charging head to be electrically coupled to the charge collector of the load handling device. More preferably, the charging head is mounted to a movable arm to electrically couple with the charge collector of the load handling device. For example, one end of the arm is mounted to the rail, and the charging head is mounted to the other end of the arm. Preferably, the arm is movable in response to a signal from a controller. For example, the arm is instructed to move the charging head to electrically couple the charging head mounted at one end of the arm with the charge collector mounted on the exterior surface of the vehicle body. Alternatively, the charging head can be mounted to one of the rails or tracks on the lattice framework to mate with the charge collector mounted on the skirt of the vehicle body.

[0032] In an alternative embodiment of the present invention, a charging head is connectable to a charge collector for charging a rechargeable power supply of a load handling device under the action of an electromagnet. Preferably, the electromagnet is activated or actuated when a charge supply pad of the charging head contacts a charge receiving pad of the charge collector. When the electromagnet is activated or actuated, i.e., switched on, a force in the range of 40 Newtons can be established between the contact surfaces of the charge collector and the charging head. Preferably, the electromagnet is activated or actuated by an actuator such that when the actuator is actuated, the electromagnet is activated or actuated to be attracted toward the charging head. Optionally, the actuator can be a contact switch having an open circuit configuration when actuated. Preferably, the charging head is positioned to descend under gravity into contact with the charge collector such that when the charge supply pad of the charging head contacts the charge receiving pad of the charge collector, the electromagnet is activated or actuated by the actuator (the actuator activates or actuates the electromagnet). In an example where the actuator is a contact switch, the contact switch is in a closed configuration as the charging head is lowered under gravity toward the charging head. When the charging head contacts the charge collector, the contact switch is interrupted, i.e., the circuit is broken. The interruption of the contact switch activates or operates an electromagnet, which draws the charging head into contact with the charge collector under the effect of the electromagnet's magnetic attraction. Preferably, the charge receiving pads of the charge collector and / or the charge delivery pads of the charging head are each biased outward by a resilient member (spring loaded) to increase the surface contact area and the clamping force between the charging head and the charge collector. More preferably, the charge receiving pads of the charge collector and / or the charge delivery pads of the charging head are each spring-loaded to reduce the impact the charging pads have on each other.

[0033] Preferably, the control system is operable to provide current to charge the rechargeable power source in response to the electromagnet being activated or actuated. The use of an actuator to switch on or increase current, which can be as much as 160 amps, from the power source charger to the rechargeable power source within the load handling device helps mitigate arcing between the contact pads of the charging head and the charge collector. Initially, a small or zero voltage is established between the charging head and the charge collector, low enough to prevent arcing between the respective contact pads when in contact. Once connection is made between the charging head and the charge collector, the control system is instructed to provide or increase charging current to the rechargeable power source through the charging head, for example, via the interruption of a contact switch. Preferably, the control system is operable to provide current to the rechargeable power source a predetermined time after the electromagnet is activated or actuated. By transferring power to the rechargeable power source a predetermined time after the electromagnet is activated or actuated, arcing between the charging head and the charge collector is mitigated. The predetermined time serves to allow the electromagnet to apply sufficient pulling force of the charging head to the charge collector to establish a relatively low contact resistance between the contact pads, i.e., to establish maximum contact surface area, so that when current, which can be as much as 160 amps, begins to flow through the charging head to the charge collector, the low contact resistance mitigates any excessive arcing.

[0034] Preferably, the charging head is guided vertically by at least one guide member.

[0035] Preferably, the charging head is lifted and disconnected from the charge collector by a linear actuator, the linear actuator being arranged to lift the charging head and remove it from the charge collector of the load handling device, for example after a charging operation.

[0036] The present invention provides a method of charging a rechargeable power source of a cargo handling device in a storage system of the present invention, the method comprising: a) lowering a charging head toward a charge collector of a charging point; b) activating an electromagnet to pull the charging head toward the charge collector under magnetic attraction when the charging head contacts the charge collector; and c) supplying current to the rechargeable power source via the charging head.

[0037] Preferably, the method comprises: d) activating or actuating the electromagnet in response to a signal from the actuator.

[0038] Preferably, the method further comprises the step of supplying current to the rechargeable power source a predetermined time after the electromagnet is activated or actuated.

[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 lattice framework structure according to a known system. [Figure 2] FIG. 2 is a schematic diagram of a top view showing a stack of vessels arranged within the lattice framework structure of FIG. [Figure 3] FIG. 3 is a schematic diagram of a known system of load handling devices operating on a lattice framework structure. [Figure 4] FIG. 4 is a schematic perspective view of a load handling device showing a lifting device gripping a container from above. [Figure 5]5(a) and 5(b) are schematic perspective cross-sectional views of the load handling device of FIG. 4 showing a container receiving space of the load handling device and a container accommodated within the container receiving space of the load handling device. [Figure 6] FIG. 6 is a schematic diagram illustrating a known charging station with a charging unit suspended from a support structure. [Figure 7a] FIG. 7a is a schematic view from above of a known charging unit or charging head. [Figure 7b] FIG. 7b is a schematic view from below of a known charging unit or charging head showing the power transfer unit. [Figure 8] FIG. 8 is a schematic diagram of the top view of a known load handling device. [Figure 9] FIG. 9 is a schematic perspective view of a charging contact system showing a charge collector mating with a charging head according to a first embodiment of the present invention. [Figure 10] FIG. 10 is a schematic perspective view of a charging contact system illustrating disconnection of the charging system according to a first embodiment of the present invention. [Figure 11] FIG. 11 is a schematic perspective side view of a load handling device docked to a charging station in one configuration, in accordance with a first embodiment of the present invention. [Figure 12] FIG. 12 is a schematic perspective side view of a load handling device docked to a charging station in a second configuration, in accordance with a first embodiment of the present invention. [Figure 13] FIG. 13 is a schematic perspective side view of a load handling device docked to a charging station in a third configuration, in accordance with a first embodiment of the present invention. [Figure 14] FIG. 14 is a schematic perspective view of a charging head engaged with a charge collector on a load handling device in accordance with a second embodiment of the present invention. [Figure 15] FIG. 15 is a perspective side view of a charging head detached from a charge collector on a load handling device according to a second embodiment of the present invention. [Figure 16]FIG. 16 is a schematic perspective side view of a charging head engaged with a charge collector on a load handling device in accordance with a second embodiment of the present invention. [Figure 17] FIG. 17 is a block diagram illustrating an example of a charging control system according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0041] The present invention addresses known features of storage systems such as the lattice framework structures and load handling devices described above with reference to Figures 1 to 6.

[0042] 9 and 10 illustrate docking and disconnection, respectively, of a charging contact system according to a first embodiment of the present invention. The charging contact system includes a charging point 80 disposed on the body of the load handling device and a charging head 84 forming a charging station 82. The charging contact system according to the present invention utilizes a charging system commercially available from RoboteQ®, headquartered at 7812 E. Acoma Dr. Suite 1, Scottsdale, AZ 85260, USA. The charging point 80 includes a charge collector 86 having at least two charge receiving pads 88 arranged to cooperate with at least two charge supply pads 90 of the charging head 84. Power is supplied to the charging head 84 by a suitable power supply charger (not shown). In a specific embodiment of the present invention, the two charge supply pads provide direct current, i.e., one of the charge supply pads 90 is DC- and the other is DC+. The charge collector 86 is movably disposed relative to the body of the load handling device. In a specific embodiment of the present invention, the charge collector 86 is extendable from and retractable within an outer housing 92. More specifically, charge receiving pad 88 is mounted to an inner housing that is telescopically movable within outer housing 92. Figure 9 shows charge collector 86 in both the retracted and extended configurations.

[0043] Although the container receiving space 40 for accommodating the container when the container is lifted by the crane mechanism is located within the vehicle body 32 shown in FIG. 5 , the present invention is not limited to the container receiving space 40 being located within the vehicle body 32. The present invention is also applicable to a container receiving space located below a cantilever, such as when the vehicle body of a load handling device has a cantilever structure, as described in WO 2019 / 238702 (Autostore Technology AS). For purposes of the present invention, the term "vehicle body" is interpreted as optionally covering the cantilever so that a gripping device is positioned below the cantilever. However, for ease of explanation of the present invention, the container receiving space for receiving the container is located within a cavity or recess within the vehicle body.

[0044] The outer housing 92 of the charging point 80 is attached to the body of the load handling device so that the charge collector is movable relative to the body. Any means for attaching the outer housing 92 to the body, such as bolts, screws, or adhesives, is applicable to the present invention. The charge collector 86 includes one or more magnets (not shown) arranged to be attracted to one or more magnets (not shown) in the charging head 84 when the charge collector 86 is positioned over the charging head 84; i.e., different poles of the one or more magnets in both the charge collector 86 and the charging head are aligned. Magnetic attraction causes the charge receiving pad 88 of the charge collector 86 to move toward and physically contact the charge delivery pad 90 of the charging head 84. This is clearly indicated by the arrows in FIG. 9 . The one or more magnets are permanent magnets, preferably rare earth magnets. The use of rare earth magnets provides the necessary pulling force to physically clamp the charge receiving pad of the charge collector to the charge delivery pad of the charging head with sufficient force to prevent arcing and reduce contact resistance. Typically, a clamping force of 40 N is required to prevent arcing and reduce contact resistance. Examples of rare earth magnets include, but are not limited to, neodymium magnets and samarium cobalt magnets.

[0045] Disconnecting the charge collector 86 from the charging head 84 includes moving the charge collector 86 to repel one or more magnets in the charge collector 86 from one or more magnets in the charging head 84. Optionally, the charging head 84 includes two or more sets of magnets, each set including at least one magnet positioned side by side. A first set of magnets in the charging head is positioned to magnetically attract one or more magnets in the charge collector 86. A second set of magnets in the charging head is positioned to magnetically repel one or more magnets in the charge collector 86. The reverse is also applicable, in which the charge collector 86 includes two or more sets of magnets positioned to magnetically attract and / or repel one or more magnets in the charging head. In use, the charge collector attached to the load handling device is moved along the charging head 84 so that like poles of one or more magnets in both the charge collector 86 and the charging head 84 are aligned. The strong repulsive force experienced by the charge collector causes the charge collector 86 to momentarily retract into the outer housing 92, thus lifting it from the charging head 84 so that the load handling device continues on its course along the track. This is indicated by the push arrow shown in FIG. 10. The alignment of the charge collector with the charging head can take the form of the load handling device positioning itself relative to the charging station. Thus, in a first position of the load handling device relative to the charging station, the charge collector 86 extends into contact with the charging head 84, and in a second position of the load handling device relative to the charging station, the charge collector 86 retracts and is disconnected from the charging head 84.

[0046] The charge collector 86 can be held in its stored configuration by the magnetic attractive force of one or more magnets within the charge collector 86. A strong rare earth magnet is positioned within the charging head 84 to allow the charge collector 86 to be drawn toward the charging head 84, which overcomes the magnetic attractive force holding the charge collector 86 in its stored configuration. By controlling the strength of the magnets within the charging head 84 and the charge collector 86, the charge collector 86 can be held in its stored configuration to safely traverse along rails or tracks on a lattice framework structure, and when docked with a charging station, the strong magnetic attractive force of one or more magnets within the charging head 84 overcomes the magnetic attractive force holding the charge collector 86 in its stored configuration, causing the charge collector 86 to move and be drawn toward the charging head 84. In an alternative configuration, the charge collector is held (or biased) in its stored configuration within the outer housing 92 by a resilient member, for example, by using a spring, and is drawn toward the charging head only by the magnetic attraction that develops between the charging head and the charge collector, overcoming the biasing force. This eliminates the need for a separate set of magnets to store the charge collector within its outer housing.

[0047] 9 and 10 describe the charge collector 86 as being movable relative to the charging head 84, the reverse is equally applicable where the charge collector 86 is fixed and the charging head 84 is movable toward the charge collector 86 during charging operations. This eliminates the need for the charge collector 86 to be retracted (e.g., elevated) to provide clearance for the load handling device to move along the rails, since the charge receiving pad 88 of the charge collector 86 can be substantially flush with the surface of at least one wall of the vehicle body, or can at least slightly protrude from the surface of at least one wall of the vehicle body, but be clear enough so as not to present an obstruction when moving on the rails. During charging operations, when the load handling device is docked at the charging station, the charging head 84 is movable to extend toward the charge collector 86 under a strong magnetic attraction force as a result of the charge collector 86 and one or more magnets within the charging head 84. While it is beneficial for the charging head 84 to be disconnected from the charge collector by magnetically retracting into its outer housing, this is not a required action, as the charging head 84 is always in a fixed position and therefore does not present itself as an obstruction. Movement of the load handling device may result in the charge collector being disconnected from the charging head. However, moving either the charge collector 86 or the charging head 84 toward each other helps mitigate potential alignment issues between the contact surfaces of the charge-receiving pad 88 of the charge collector 86 and the charge-delivery pad 90 of the charging head 84. Similarly, moving either the charge collector 86 and / or the charging head 84 toward each other also helps accommodate differences in the height of the load handling device.

[0048] The charging contact system of the present invention shown in Figures 9 and 10 can be mounted in different areas of the vehicle body, thereby providing different charging schemes. Figures 11 to 13 illustrate different charging schemes according to the present invention. Figure 11 shows an example in which the movable part of the charging contact system of the present invention, representing the charging head, is pulled toward a charge collector fixed to the top wall 94 of the load handling device. The charging point 80 shown in Figure 11 is located on the exterior surface of the top wall 94 of the vehicle body 32. This allows the charging head 84 of the present invention to be installed in an existing charging station having the L-shaped framework 50 described above in the introduction to this patent specification. The charging head 84 is suspended from the L-shaped framework 50 and positioned to cooperate with a charge collector 86 mounted on the top wall 94 of the vehicle body 32 when the load handling device 30 is docked below the charging head 84 of the charging station 82.

[0049] In another charging arrangement, the charging point 80 is located on one of the side walls 96 of the vehicle body 32, as shown in FIG. 12. In this configuration, charging occurs by docking the load handling device 30 laterally sideways onto the charging station 82, as indicated by the arrow shown in FIG. 12. This allows the charging head 84 to be attached to a side wall adjacent to a lattice framework structure or guardrail installed to accommodate the charging station, eliminating the need for a dedicated framework for suspending the charging head above the load handling device, as shown in FIG. 11. Similar to the arrangement shown in FIG. 11, the charge collector 86 can be made movable relative to the vehicle body 32; that is, the charging contact system of the present invention can be oriented such that the charge collector 86 is movable so as to be drawn toward the charging head 84, which remains fixed when docked with the charging station 82.

[0050] To eliminate clutter around the lattice framework structure, the charging contact system of the present invention can be positioned at the floor level of the lattice framework structure. As shown in FIG. 13 , the charge collector 86 can be attached to a foot of the car body 32, for example, to a bottom edge of the skirt of the car body 32. The car body 32, which houses auxiliary components of the load handling device, such as a drive motor, includes a skirt body having a first pair of opposing sidewalls 98 and a second pair of opposing sidewalls 100. The charging point 80 is attached to the bottom edge of at least one of the first and / or second pairs of opposing sidewalls 98, 100, positioned to cooperate with a charging head 84 mounted on a rail or track 102 on the lattice framework structure. In this manner, charging occurs when the load handling device 30 travels over and is positioned on the charging point 80, more specifically, the rail or track 102 having the charging head 84 mounted thereon for electrical coupling with the charge collector 86. A movable arm (not shown) can be used to precisely position the charging head 84 over the charge collector 86 so that the corresponding charge delivery pads 90 and charge receiving pads 88 are properly aligned. The movable arm can be a robotic arm with one end attached to a track or grid within the grid cells, with the charging head attached to the other end of the movable arm. During a charging operation, the movable arm is commanded by a controller to position the charging head 84 into engagement with the charging point 80 of the load handling device 30, and more specifically, with the charge collector 86, such that either the charging head 84 or the charge collector 86, depending on which is the movable component, are drawn toward each other by magnetic attraction. The movable arm can be pivotally mounted to rails on the grid structure or grid framework structure.

[0051] Although the embodiments shown in Figures 11, 12, and 13 illustrate different placements of the charging contact system mounted on the vehicle body, the present invention is not limited to the orientations shown in Figures 11-13. The charging point of the present invention can be mounted in other areas of the vehicle body. Additional charging contacts of the present invention can be incorporated into the system to monitor the status of the battery. Thus, instead of functioning as a charge collector, one or more additional contact pads can be mounted on the load handling device to cooperate with corresponding contact pads on the charging station to provide information about the battery's status. The contact pads can have the same function as the charging contact system of the present invention described above, in that one or more contact pads are retractable within the outer housing under the influence of one or more magnets. A control system can ensure that the charging pads provide the required current based on the condition of the rechargeable battery. The condition may be based on at least one of voltage, temperature, state of charge, depth of discharge, and state of health. The charge collector 86 or charging head can be retractable within the outer housing by either magnetic force or a resilient member (e.g., a spring).

[0052] In an alternative embodiment of the present invention, the magnetic attraction between the charging head and the charge collector can be generated by an electromagnet rather than by one or more permanent magnets. An advantage of using an electromagnet over a permanent magnet is that the electromagnet can be controlled to generate the necessary magnetic attraction to pull the charging head into engagement with or physical contact with the charge collector, for example, by controlling the current through the coil that constitutes the electromagnet. An example of an electromagnet is a solenoid wound around a magnetic core, as is commonly known in the art. In this manner, one or more actuators attached to the charging station can be used to activate or actuate the electromagnet to provide the necessary magnetic attraction and physically clamp the charging head against the charge collector. In a specific embodiment of the present invention, shown in FIGS. 14-16 , a charging contact system 104 includes a charging station 101 including a charging head 184 attached to a support platform 106 that is movable downwardly from a first position where the charging head is spaced apart from the charge collector to a second position where the charging head is in physical contact with the collector. In a specific embodiment of the present invention, the charging head is configured to move from the first position to the second position under the action of gravity. The charging head 184 is attached to the bottom wall of the movable platform 106 and is adapted to cooperate with a charging point 185 that includes the charge collector 186 when the charging head 184 is lowered onto the charge collector 186. The platform 106 is guided for vertical movement by at least one guide member 108, such as a guide rod. The platform is freely movable along the guide member 108, allowing the platform to fall vertically under its own weight, i.e., gravity. A damper commonly known in the art, such as one or more springs or gas springs, can be used to slow or damp the fall of the platform along the at least one guide member, thus reducing the impact of the charging head against the charge collector.

[0053] One or more electromagnets 116 are mounted to the support platform 106. The one or more electromagnets 116 are positioned to magnetically attract the charging head 184 to a charge collector 186 mounted on the top wall of the vehicle body 32 when the one or more electromagnets 116 are activated or actuated, i.e., when current is switched on through the coils of the electromagnets. In certain embodiments of the invention, the one or more electromagnets 116 are positioned on at least one edge of the platform to distribute a clamping force across the platform and, therefore, across the contact pads 188, 190 of the charging head 84 and charge collector 86 when the electromagnets are activated or actuated.

[0054] To decouple the charging head 184 from the charge collector 186, for example, once the charging operation is complete, the platform 106 is raised from the charge collector 186. In certain embodiments of the invention, the platform 106 is raised by a linear actuator 110. As shown in FIGS. 14 to 16, the linear actuator 110 includes a shaft 112 . The foot or end of the shaft 112 includes a stop 114 positioned to contact or abut the bottom wall or underside of the platform 106 as the linear actuator moves upward to raise the platform 106. Various linear actuators commonly known in the art for lifting platforms are applicable in the present invention, including, but not limited to, mechanical, hydraulic, pneumatic, piezoelectric, or electromechanical actuators.

[0055] The charge collector 186, which includes a charge-receiving pad, comprises a ferromagnetic material, such as iron, that can be magnetically attracted to the charging head 184 when one or more electromagnets are activated or actuated. The one or more electromagnets 116 are activated or actuated in response to a signal from an actuator. In a specific embodiment of the invention, the actuator is a contact switch 118 that breaks a circuit and activates or actuates the electromagnets when the charging head 184 contacts the charge collector 186. For example, the contact switch is formed of two parts that separate to break the electrical circuit and come together to complete the electrical circuit when the charging head is disconnected from the charge collector. As shown in FIG. 15 , one portion of the contact switch 118 is attached to the platform 106 that supports one or more of the electromagnets, and the other portion is attached to the linear actuator 112. As illustrated by the schematic diagram in FIG. 15 , the contact switch 118 is closed (i.e., in contact) when the charging head 184 is spaced or separated from the charge collector 186. Conversely, when the charging head 184 contacts or approaches the charge collector 186, e.g., when their corresponding pads contact, the contact switch 118 opens, resulting in a circuit interruption, as demonstrated by the schematic diagram in FIG. 16 . The interruption of the circuit is an indication that the charging head 184 is in contact with the charge collector 186 and activates or operates the electromagnet via an appropriate control device. The actuator that activates or operates the electromagnet 116 is not limited to a contact switch; any type of actuator that provides a signal indicating that the charging pads of the charging head 184 are in physical contact with the corresponding charging pads of the charge collector 186, and vice versa, is applicable in the present invention. For example, one or more sensors, such as a depth sensor, can be used to provide an indication that the charging head is in contact with the corresponding charging pads of the charge collector. Similarly, the length of travel of the linear actuator 110 can be used to determine when the charging head 184 contacts the corresponding charging pads of the charge collector 186.

[0056] The signal from the actuator 118 can be used by the controller to activate or actuate the electromagnet 116, which then controls the charging operation. To monitor the status of the rechargeable power source, i.e., to ensure that the charging head provides the required current based on the status of the rechargeable power source, one or more additional contact pads can be attached to the charging head 184 or the platform 106 supporting the charging head. As shown in the block diagram of FIG. 17 , the signal from the actuator 118 is input to the controller 120, and in response to the input signal from the actuator, the controller activates or actuates the electromagnet to draw the charging head 184 toward the charge collector 186, establishing sufficient contact pressure between the charging head and the charge collector, which then transfers power from a power source (not shown) to charge the rechargeable power source. The charging head and / or charge collector can be resiliently mounted and outwardly biased, e.g., spring-based, to reduce shock between their respective contact pads, but most importantly, to control the clamping force under the influence of magnetic attraction. In operation when charging a rechargeable power source, the load handling device 30 is commanded to dock with the charging station. For example, a signal is sent from the load handling device to the controller 120 that the load handling device is about to dock with the charging station. Once docked, as indicated by a signal from the load handling device, the controller 120 allows the linear actuator supporting the charging head 184 to lower. For example, a locking mechanism or stop holding the linear actuator in an elevated position is disabled. This allows the platform 106 supporting the charging head 184 to freely fall under gravity, guided by the guide rods 108, toward the charge collector 186 of the load handling device. As the platform lowers and the charging head 184 remains spaced apart from the charge collector, the actuator remains closed, i.e., the contact switch is closed, as shown in FIG. 15 .At this point, the charging head 184 contacts the charge collectors 186 or their corresponding contact pad contacts, and the linear actuator 110 continues to descend, either blocking or opening the contact switch, as shown in FIG. 16. The blocking of the contact switch is an indication that the actuator has been activated, and a signal is sent to the controller 120 indicating that the actuator has been activated. When the actuator is activated, the controller 120 starts a timer to allow the linear actuator 110 (more specifically, the shaft of the linear actuator) to descend for a predetermined amount of time, as shown in FIG. 16. In certain embodiments where the linear actuator only allows the contact switch to close to activate the actuator, the timer prevents the linear actuator from hitting the top wall of the load handling device. Alternatively or additionally, the controller can determine the length of travel of the linear actuator and can lower the linear actuator a predetermined length to prevent the linear actuator from hitting the top of the load handling device.

[0057] In certain embodiments, upon actuation of the actuator, as determined by the interruption of a contact switch, the controller 120 activates or operates one or more electromagnets 116 attached to the platform 106 supporting the charging head 184, to pull the charge-delivery pad of the charging head 184 toward the charge-receiving pad of the charge collector 186 by the pulling force of electromagnetic attraction. The charging head 184 is attached to a resilient member or spring-loaded to compress by the pulling force of magnetic attraction. The resilient member provides the charging head with sufficient resilience to establish maximum surface area contact between the charging head 184 and the charge collector 186, thereby reducing contact resistance and the impact of the charging head 184 contacting the charging pad of the charge collector 186. A clamping force on the order of 40 N can be established between the contact pad of the charging head 184 and the charge collector 186, necessary to prevent arcing between the contact pads and therefore deterioration of the contact pad surfaces.

[0058] After a clamping force is established between the charging head 184 and the charge collector 186, more specifically between their respective contact pads, the controller commands a power transfer unit or power supply charger (not shown) to transfer power to the rechargeable power supply via the charging head 184. A delay can be incorporated into the system to transfer power to the rechargeable power supply once one or more electromagnets are activated or actuated. For example, a timer can be used to delay the transfer of power to the rechargeable power supply once an electromagnet is activated or actuated. After a predetermined amount of time, measured by the timer, has elapsed, the controller commands the power transfer unit to transfer power to the rechargeable power supply via the charging head 184. Incorporating a delay between the activation of the electromagnets and the transfer of power to the rechargeable power supply helps mitigate arcing, so that power is transferred through the charging head when a relatively high contact force is established between the contact pads. The high contact pressure, which can be on the order of 40 N, reduces the contact resistance between the charging head and the charge collector.

[0059] One or more additional contact pads (not shown) may be attached to the platform supporting the charging head (attached to the platform's bottom wall) to monitor the battery's status during charging and ensure that the charging pads provide the required current based on the battery's status. Once the rechargeable power source is charged or has received the required charge, the controller disconnects the charging head 184 from the charge collector 186. In the specific embodiment of the invention shown in FIGS. 14-16 , the controller commands the linear actuator 110 to raise and lift the charging head 184, and more specifically, the movable platform 106 supporting the charging head 184, from the charge collector on the load handling device. Prior to disconnecting the charging head 184 from the charge collector 186, the electromagnet 116 is preferably switched off, allowing the linear actuator 110 to freely lift the charging head 184 and allow the contact pads of the charging head 184 to break contact with the charge collector 186. For example, disconnection of the charging head 184 can occur when the controller detects that the rechargeable power source is in a charging or fully charged state. In response to detecting that the rechargeable power supply is in a fully charged state, the controller deactivates the electromagnet, i.e., switches off the current to the electromagnetic coil, allowing the linear actuator 110 to freely lift the charging head 184 away from the charge collector 186. This allows the linear actuator 110 to lift the charging head 184 attached to the platform without being attracted to the charge collector 186 as a result of electromagnetic attraction. Disconnection is established when the linear actuator 110 rises and the contact switch reconnects, closing contact switch 118. Continued elevation of platform 106 raises charging head 184 further away from the charge collector, as shown in FIG. 15. At this point, charging head 184 is spaced apart from charge collector 186. Once the charging head is lifted off the charge collector and contact switch 118 reestablishes connection, the load handling device is free to move away from the charging station. As discussed above with respect to electromagnet activation or actuation, a timer can be used to control the upward movement of the linear actuator, and therefore the charging head, when the actuator is closed, i.e., when the contact switch is closed.

[0060] The different operations of the charging contact system according to the second embodiment of the present invention can be summarized in the block diagram shown in FIG. 17. An input signal to the controller 120 is provided by the actuator and indicates the position of the charging head relative to the charge collector. The controller 120 controls the operation of the electromagnet 116 and power to the charging head. In response to the signal from the actuator, i.e., when the contact switch 118 is interrupted (see FIG. 16), the controller activates or operates the electromagnet 116 by switching on current through the solenoid that constitutes the electromagnet. A strong magnetic attraction pulls the charging head against the charge collector with enough force to establish a maximum clamping force. Typically, a clamping force of 40 N or more is required to prevent arcing and reduce the contact resistance between the charging head and the charge collector. Once sufficient clamping force is established by the electromagnet's pulling force, the controller switches on the power transfer unit to transfer power to the rechargeable power source via the charging head.

[0061] When the rechargeable power source is fully charged, a signal is sent to the controller 120 to deactivate the electromagnet, and the linear actuator 110 is actuated to lift the charging head 184 away from the charge collector 186, causing the contact switch to re-establish connection. A timer can be used to control the elevation of the charging head 184 along the guide 108. For example, when the contact switch 118 is closed, a timer can be started to add a predetermined delay to allow the charging head 184 attached to the platform 106 to be lifted away from the charge collector 186. Alternatively, the controller 120 can determine the length of travel of the charging head 184 along the guide 108, thereby commanding the linear actuator 110 to lift the charging head 184 a predetermined distance. When the contact switch 118 is closed, a signal is sent to the controller 120 indicating that the load handling device is free to move away from the charging station.

[0062] Different combinations of features of the charging contact system in the first embodiment shown in Figures 9 and 10 and the second embodiment shown in Figures 14-16 can be used without departing from the scope of the invention as defined in the claims. For example, the one or more permanent magnets for attracting the charging head into contact with the charge collector in the first embodiment of the invention shown in Figures 9 and 10 can be replaced with one or more electromagnets, and a controller can activate / actuate the electromagnets to bring the charging head into contact with the charge collector, as described in the second embodiment of the invention. In both embodiments of the invention shown in Figures 9 and 10 and 14-16, the rechargeable power source is optionally housed within the vehicle body 32 (see Figures 4 and 5). The following is a summary of the claims as originally filed: [1] A load handling device (30) for lifting and moving stacked containers (10) in a storage system (1) comprising a lattice framework structure (14) with pathways (22) arranged in a lattice pattern above the stack of containers, said load handling device (30) comprising: a body (32) housing a drive mechanism operatively arranged to move said load handling device (30) on said lattice framework structure (14); a lifting device comprising a lifting drive assembly and a gripping device (39) configured in use to releasably grip a container (10) and lift the container (10) from the stack into a container receiving space (40), wherein the drive mechanism and the lifting drive assembly are powered by a rechargeable power source electrically coupled to a charging point (80, 185) arranged on the vehicle body (32) for electrically coupling to a charging head (84, 184) of a charging station (82, 101) in use, the charging point (80, 186) comprising a charge collector (86, 186) connectable to the charging head (84, 184) of the charging station (82, 101) under the action of a magnet. [2] The load handling device (30) according to [1], wherein the charge collector is connectable to the charging head of the charging station under the action of an electromagnet. [3] The load handling device (30) according to [1] or [2], wherein the charge collector (86, 186) is movable relative to the vehicle body (32) under the action of the magnet to connect to the charging head (84, 184) of the charging station (82, 101). [4] The load handling device (30) of [3], wherein the charge collector comprises one or more magnets. [5] The load handling device (30) according to [4], wherein the one or more magnets are rare earth magnets. [6] The load handling device (30) according to [5], wherein the one or more rare earth magnets are neodymium magnets. [7] The load handling device (30) of any one of [3] to [6], wherein the charge collector (86) is extendable from or retractable within the outer housing (92). [8] A cargo handling device (30) as described in any one of [3] to [7], wherein the charging point (80, 185) is mounted on an outer surface of at least one wall (94, 96, 98, 100) of the vehicle body. [9] The load handling device (30) according to [8], wherein the wall is a side wall (96) of the vehicle body (32).

[10] A cargo handling device (30) as described in any one of [3] to [9], wherein the vehicle body (32) comprises a skirt having a first pair of opposing side walls (98) and a second pair of opposing side walls (100), and the charging point (80, 185) is attached to a bottom edge of at least one of the first and / or second pairs of opposing side walls (98, 100).

[11] The load handling device (30) of any one of [1] to

[10] , wherein the charge collector (86, 186) comprises at least two charge receiving pads (88, 188) arranged to be connectable to at least two charge supply pads (90, 190) of the charging head (84, 184).

[12] A storage system (1), comprising: i) a lattice framework structure (14) supporting pathways (22) arranged in a lattice pattern comprising a plurality of lattice spaces or lattice cells; ii) a load handling device (30) for lifting and moving the containers (10) stacked within the lattice framework structure (14), a) a body (32) housing a drive mechanism operatively arranged to move said load handling device (30) on said lattice framework structure; b) a lifting device comprising a lifting drive assembly and gripping device (39) configured, in use, to releasably grip a container (10) and lift said container (10) from the stack into the container receiving space (40); a load handling device (30), wherein the drive mechanism and the lifting drive assembly are powered by a rechargeable power source electrically coupled to a charging point (80, 185) located on the vehicle body (32) that includes a charge collector (86, 186); iii) a charging station (82, 101) comprising a charging head (84, 184) electrically coupled to the power charger; 10. A storage system (1), wherein the charging head (84, 184) is connectable with the charge collector (86, 186) for charging the rechargeable power source of the load handling device under the action of a magnet.

[13] The storage system (1) of

[12] , wherein the charge collector (86, 186) comprises at least two charge-receiving contact pads (88, 188) arranged to be connectable to at least two charge-supplying contact pads (90, 190) of the charging head (84, 184).

[14] The storage system (1) according to

[12] or

[13] , wherein the charge collector and / or the charging head (84, 184) are movable to be electrically coupled to each other under the action of the magnet.

[15] The storage system (1) of

[14] , wherein the charge collector (86, 186) and / or the charging head (84, 184) are extendable from or retractable within the outer housing (92).

[16] The storage system (1) of any one of

[12] to

[15] , wherein the charge collector (86, 186) and the charging head (84, 184) of the charging station (82, 101) are arranged to be electrically coupled to each other under the action of magnetic attractive force and electrically disconnected from each other under the action of magnetic repulsive force.

[17] The storage system (1) according to

[16] , wherein the charge collector (86, 186) and the charging head (84, 184) each comprise one or more magnets.

[18] The storage system (1) of

[17] , wherein one or more of the magnets of the charge collector (86, 186) or the charging head (84, 184) comprises a rare earth magnet.

[19] The storage system (1) according to any one of

[12] to

[18] , wherein the charging head (84, 184) is attached to the path (22).

[20] The storage system (1) according to

[19] , wherein the charging head (84, 184) is mounted on a movable arm so as to be electrically coupled to the charge collector (86, 186) of the load handling device (30).

[21] The storage system (1) according to

[20] , wherein the arm is movable in response to a signal from a control device.

[22] The storage system (1) according to any one of

[12] to

[21] , wherein the charging point (80, 185) is attached to the outer surface of at least one wall (94, 96, 98, 100) of the vehicle body (30).

[23] The storage system (1) according to

[22] , wherein the wall is a side wall (96) of the vehicle body (30).

[24] The storage system (1) of any one of

[12] to

[23] , wherein the vehicle body (30) comprises a skirt having a first pair of opposing side walls (98) and a second pair of opposing side walls (100), and the charging point (80, 185) is attached to a bottom edge of at least one of the first and / or second pairs of opposing side walls (98, 100).

[25] The storage system (1) of any one of

[12] to

[24] , wherein the charging head (184) is connectable to the charge collector (186) for charging the rechargeable power source of the load handling device (30) under the action of an electromagnet (116).

[26] The storage system (1) according to

[25] , wherein the electromagnet is activated when a charge supply pad (188) of the charging head (184) is in contact with a charge receiving pad (190) of the charge collector (186).

[27] The storage system (1) according to

[26] , wherein the electromagnet (116) is activated by an actuator (118).

[28] The storage system (1) according to

[27] , wherein the actuator is a contact switch (118).

[29] The storage system (1) of any one of

[25] to

[28] , further comprising a controller (120) operable to provide current to charge the rechargeable power source in response to the electromagnet (116) being activated.

[30] The storage system (1) of any one of

[25] to

[29] , wherein the charging head (184) is movable between a first position in which the charging head is spaced apart from the charge collector (186) and a second position in which the charging head (184) is in physical contact with the charge collector (186).

[31] The storage system (1) according to

[30] , wherein the charging head (184) is guided vertically by at least one guide member (108).

[32] The storage system (1) of

[30] or

[31] , wherein the charging head (184) is movable to the second position under the action of gravity so as to contact the charge collector (186).

[33] The storage system (1) of any one of

[30] to

[32] , wherein the charging head (184) is lifted to the first position by a linear actuator (110) to remove the charging head (184) from the charge collector (186) of the cargo handling device (30).

[34] The storage system (1) according to

[33] , wherein the electromagnet is activated when the linear actuator is extended by a predetermined length.

[35] A method for charging a rechargeable power source of a cargo handling device (30) in a storage system (1) according to any one of

[25] to

[34] , comprising: a) lowering the charging head (184) towards the charge collector (186) of the charging point (185); b) activating the electromagnet (116) to pull and / or push the charging head (184) towards the charge collector (186) under magnetic attraction; and c) supplying current to the rechargeable power source through the charging head (184).

[36] The method of

[35] , further comprising the step of: d) activating the electromagnet (116) in response to detecting a signal from an actuator (118).

Claims

1. A storage system (1), comprising: i) a lattice framework structure (14) supporting pathways (22) arranged in a lattice pattern comprising a plurality of lattice spaces or lattice cells; ii) a load handling device (30) for lifting and moving containers (10) stacked within said lattice framework structure (14), a) a body (32) housing a drive mechanism operatively arranged to move said load handling device (30) on said lattice framework structure; b) a lifting device comprising a lifting drive assembly and gripping device (39) configured, in use, to releasably grip a container (10) and lift said container (10) from the stack into the container receiving space (40); a load handling device (30), wherein the drive mechanism and the lifting drive assembly are powered by a rechargeable power source electrically coupled to a charging point (80, 185) located on the vehicle body (32) that includes a charge collector (86, 186); iii) a charging station (82, 101) comprising a charging head (84, 184) electrically coupled to the power charger; the charging head comprises at least two charge delivery pads; the charging head (84, 184) is connectable to the charge collector (186) for charging the rechargeable power supply of the load handling device under the action of an electromagnet (116); the electromagnet is activated by an actuator when at least two charge supply pads (188) of the charging head (184) are in contact with at least two charge receiving pads (190) of the charge collector (186); the charging head (184) is movable from a first position where the charging head is spaced from the charge collector (186) to a second position where the charging head (184) is in physical contact with the charge collector (186); The storage system (1), wherein the charging head (184) is movable under the action of gravity to the second position so as to contact the charge collector (186).

2. 2. The storage system (1) of claim 1, wherein the actuator is a contact switch (118).

3. 3. The storage system (1) of claim 1 or 2, further comprising a controller (120) operable to provide current to charge the rechargeable power source in response to the electromagnet (116) being activated.

4. 4. The storage system (1) according to any one of claims 1 to 3, wherein the charging head (184) is guided vertically by at least one guide member (108).

5. 5. The storage system (1) of claim 1, wherein the charging head (184) is lifted to the first position by a linear actuator (110) to detach the charging head (184) from the charge collector (186) of the cargo handling device (30).

6. 6. The storage system (1) of claim 5, wherein the electromagnet is activated when the linear actuator extends a predetermined length.

7. A method for charging a rechargeable power supply of a load handling device (30) in a storage system (1) according to any one of claims 1 to 6, comprising the steps of: a) lowering the charging head (184) towards the charge collector (186) of the charging point (185); b) activating the electromagnet (116) to pull and / or push the charging head (184) towards the charge collector (186) under magnetic attraction; and c) supplying current to said rechargeable power source through said charging head (184).

8. 8. The method of claim 7, further comprising the step of: d) activating the electromagnet (116) in response to detecting a signal from an actuator (118).

Images