Material handling system with input / output station and method of use

Abstract

A transfer station for the material handling system is provided. The material handling system may include multiple vehicles that retrieve multiple items from multiple storage locations arranged in one or more racks. The transfer station accommodates vehicles such that the vehicles enter the transfer station and are driven upward along tracks within the transfer station. A transfer mechanism on the vehicle cooperates with a transfer mechanism at the transfer station to move items from the vehicle to the conveyor.

Description

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 410,211, filed September 26, 2022. The entire disclosure of the above application is incorporated herein by reference. The present invention relates to a material handling system for storing or retrieving items. More specifically, the present invention relates to a material handling system incorporating multiple destination areas and multiple vehicles that transport items to and / or from the multiple destination areas and to and / or from one or more work sites. [Background technology]

[0002] Storing and retrieving items to fulfill customer orders can be difficult and time consuming in systems that store thousands of items. Manually storing and retrieving items from thousands of storage areas requires significant effort. Automated picking has been developed in many areas to reduce labor costs and improve customer service by reducing the time to fulfill customer orders. However, known systems for automated material handling are either very expensive or have limitations that hinder their effectiveness. Therefore, there is a need for automated storage and / or retrieval of items in various material handling applications. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Patent No. 11,254,504 Summary of the Invention [Problem to be solved by the invention]

[0004] The present invention provides aspects related to material handling and / or storage and retrieval processes. [Means for solving the problem]

[0005] According to one aspect of the present invention, a material handling system is provided that includes a storage mechanism for housing a plurality of containers, a plurality of transport vehicles, a transfer station, and a first horizontal conveyor for transporting the plurality of containers from the transfer station.

[0006] The storage mechanism may then include a plurality of storage locations that are vertically spaced apart from one another. For example, the storage locations may be arranged in a series of vertically spaced rows or in a series of columns.

[0007] Optionally, the storage mechanism may include a track disposed adjacent to the plurality of storage locations.

[0008] The plurality of vehicles are configured to transport the plurality of containers and retrieve one of the plurality of containers from one of the plurality of storage locations. Similarly, the plurality of vehicles may be configured to store one of the plurality of containers in one of the plurality of storage locations.

[0009] The plurality of vehicles may include a drive mechanism for driving the vehicles along the track to a first storage location so that the vehicles retrieve a first container of the plurality of containers.

[0010] Optionally, each vehicle may include a rechargeable power source to power the drive mechanism.

[0011] Each vehicle may include a surface that supports one of the plurality of containers.

[0012] The material handling system may include a central controller that controls the operation of each of the multiple vehicles.

[0013] Optionally, the drive mechanism of each vehicle includes one or more rotatable elements. For example, the drive mechanism may include a number of wheels or rollers.

[0014] The drive mechanism may include a horizontal drive mechanism and a vertical drive mechanism.

[0015] Optionally, the horizontal drive mechanism may be configured to drive the vehicle along a horizontal plane. The vertical drive mechanism may be configured to drive the vehicle vertically along the track. For example, the first storage location may be located above a horizontal surface, and the vertical drive mechanism may be configured to drive the vehicle upwardly toward the first storage location.

[0016] The drive mechanism may include a work station for obtaining one or more items from the plurality of containers, and the first horizontal conveyor may be configured to transport the containers from the transfer station to the work station.

[0017] The first horizontal conveyor may be configured to receive the plurality of containers and transport the plurality of containers along the first horizontal path to the work station. Optionally, the first horizontal path is in a first direction.

[0018] Optionally, the first horizontal conveyor includes a circular path including a first section for moving the plurality of containers from the transfer station and a second section for moving the plurality of containers to the transfer station.

[0019] Optionally, the transfer station receives multiple containers from multiple vehicles and conveys the multiple containers toward the first horizontal conveyor.

[0020] The transfer station may include a second horizontal conveyor that moves the plurality of containers along a second horizontal path toward the first horizontal conveyor. The second horizontal path may be orthogonal to the first horizontal path.

[0021] The transfer station may include a guide member for guiding the plurality of vehicles from the horizontal surface to a first transfer location disposed along the second horizontal conveyor. The material handling system may be operable to transfer a first container from the first vehicle onto a second horizontal conveyor at the first transfer location.

[0022] The transfer station may include one or more transfer locations spaced vertically apart from the first transfer location.

[0023] Optionally, the guide member may include a first track that guides the vehicle from the horizontal surface to one of the one or more transfer locations.

[0024] The first track of the guide member may include a first vertical track that cooperates with the drive mechanism to drive the vehicle upwardly to one of the one or more transfer locations.

[0025] The transfer station may include a third horizontal conveyor spaced apart from the second horizontal conveyor. The third horizontal conveyor may be operable to move the plurality of containers along a third horizontal path toward the first horizontal conveyor.

[0026] Optionally, the transfer station includes a second vertical track adjacent to the third horizontal conveyor. The second vertical track may cooperate with a drive mechanism to drive the vehicle upwardly in a path between the second horizontal conveyor and the third horizontal conveyor.

[0027] Each vehicle may include a transfer mechanism that engages multiple containers. The transfer mechanism may be configured to transfer multiple containers between the vehicle and multiple storage locations.

[0028] Optionally, the transfer mechanism may be configured to transfer the first container from the first vehicle towards the second horizontal conveyor.

[0029] The transfer mechanism may be configured to move the first container in a direction perpendicular to the second horizontal path when the first vehicle moves the first container toward the second horizontal conveyor.

[0030] Optionally, the first horizontal conveyor includes a plurality of vertically spaced, overlapping horizontal conveyors forming a plurality of conveyor tiers.

[0031] Optionally, the second horizontal conveyor includes a plurality of vertically spaced, overlapping conveyors. If the first horizontal conveyor and the second horizontal conveyor each include multiple overlapping conveyor levels, each conveyor level of the second horizontal conveyor may intersect with one of the multiple conveyor levels of the first horizontal conveyor.

[0032] According to yet another aspect, a method for storing or retrieving a plurality of containers is provided. The method uses a plurality of vehicles traveling between a plurality of storage locations where a plurality of containers are stored and a transfer station. The containers are transferred to a transfer station. From the transfer station, the containers are transported to a work station. At the work site, an operator retrieves one or more items from a plurality of containers and / or stores one or more items in a plurality of containers.

[0033] Optionally, the method includes controlling the plurality of vehicles by driving a first vehicle along a horizontal plane toward one of the one or more storage racks. The first vehicle is then moved upward from the horizontal surface to one of the plurality of storage locations and aligned with the first container.

[0034] Transferring the container to the transfer station may include driving a first vehicle with the first container along a horizontal plane between the storage rack and the transfer station.

[0035] Optionally, the first vehicle is moved vertically between a horizontal surface and a transfer location at the transfer station.

[0036] Moving the first vehicle vertically between the horizontal surface and the transfer location may include driving the first vehicle vertically over a guide member adjacent to the transfer location.

[0037] Transferring the first container may include transferring the first container between the first vehicle and a first horizontal conveyor at the transfer station.

[0038] Transferring the container may include moving the first container in a first direction toward the first horizontal conveyor.

[0039] Optionally, the first container may be conveyed along the first horizontal conveyor in a second direction that is perpendicular to the first direction.

[0040] The method may include transferring a first container from a first horizontal conveyor to a second horizontal conveyor. The second horizontal conveyor may be operable to transport the first container to the work station. The second horizontal conveyor may transport the first container in a third direction that is perpendicular to the second direction.

[0041] Optionally, transporting the first container includes transporting the first container along a conveyor loop extending from the transfer station to the work station. The conveying step may also include returning the first container along the conveyor loop to the transfer station.

[0042] Optionally, the first vehicle may be charged during the step of moving the first vehicle vertically between the horizontal surface and the transfer location.

[0043] Transferring the first container between the first vehicle and the first horizontal conveyor may include moving the first container onto a transfer mechanism. The transfer mechanism may be operable between a first position, in which the transfer mechanism is disposed at a lower position below the first horizontal conveyor, and a second position, in which the transfer mechanism is disposed above the first horizontal conveyor.

[0044] Optionally, a first container may be moved onto the transfer mechanism while the transfer mechanism is in the first position.

[0045] The step of moving the transfer mechanism to the second position may include moving the transfer mechanism into engagement with the first container.

[0046] The method may include operating a transfer mechanism to move a first container across a width of a first horizontal conveyor.

[0047] After the step of actuating the transfer mechanism, the transfer mechanism may be lowered to the first position.

[0048] Optionally, after the step of lowering the transfer mechanism to the first position, the first container may be transported from the transfer location.

[0049] The first vehicle may include a transfer mechanism operable to transfer a plurality of containers onto and from the vehicle, and the step of transferring the first container between the first vehicle and the first horizontal conveyor may include operating the transfer mechanism. [Brief explanation of the drawings]

[0050] The foregoing summary, as well as the following detailed description of embodiments of the present invention, will be best understood when read in conjunction with the accompanying drawings.

[0051] [Figure 1] FIG. 1 is a schematic plan view of a material handling system.

[0052] [Figure 2] FIG. 2 is an enlarged plan view of a portion of the material handling system shown in FIG. 1.

[0053] [Figure 3] FIG. 2 is a side view of a portion of the material handling system shown in FIG. 1.

[0054] [Figure 4] FIG. 2 is an enlarged perspective view of a transfer station of the material handling system shown in FIG. 1.

[0055] [Figure 5] FIG. 2 is a perspective view of a vehicle used in the material handling system shown in FIG. 1.

[0056] [Figure 6] FIG. 6 is an end view of the vehicle shown in FIG. 5.

[0057] [Figure 7] FIG. 6 is a side view of the vehicle shown in FIG. 5. DETAILED DESCRIPTION OF THE INVENTION

[0058] Embodiments of the present invention will be described in detail below. Referring to the drawings, like numbers refer to like parts throughout. In this specification and claims, the meanings of "a" and "the" include the plural unless the context clearly dictates otherwise. Also, in this specification and claims, the meaning of "in" includes "in" and "on," unless the context clearly dictates otherwise.

[0059] Referring now to the drawings generally, and FIG. 1 in particular, an item sorting or acquisition apparatus, i.e., a material handling system, is generally designated 10. The material handling system 10 includes one or more mechanisms for retrieving items from one of a number of locations, such as storage areas 25 located within storage racks 20 . The acquisition mechanism may include one or more vehicles that acquire items from storage locations and transport them to transfer station 200 . At the transfer station 200, the items can be transferred to an alternative material handling system, such as a conveyor system. Additionally or alternatively, items can be loaded onto vehicles at transfer station 200 and the vehicles can transport the items from transfer station 200 to storage racks 20 . Thus, material handling system 10 may include mechanisms for sequentially storing and retrieving items from various storage areas.

[0060] It should be understood that the various items and sub-features of the overall system may be used alone or in combination with material handling systems that are structured or operate differently than the systems shown in the figures and described below.

[0061] Material handling system 10 may include any of a variety of systems for storing items. For example, material handling system 10 may include a system incorporating multiple automated vehicles, such as the system described in US Pat. No. 6,329,999. The entire contents of Patent Document 1 are incorporated herein by reference.

[0062] As shown in FIG. 1, the material handling system 10 may optionally incorporate one or more storage racks 20 . Each storage rack 20 may include multiple storage locations 25 . Optionally, the storage locations 25 may be arranged in one or more vertical columns 22 . For example, FIG. 1 shows a plurality of storage racks 20, each of which may include a plurality of vertical columns 22, each of which includes a plurality of storage locations 25.

[0063] Items processed by material handling system 10 may be stored directly in storage location 25 . Alternatively, as shown in FIG. 3, the items may be stored in containers or totes 55 and the storage location 25 may be configured to store the totes 55 . It should be understood that the term tote, unless otherwise specified below, may include not only a container that holds one or more items, but also simply an item that is not necessarily contained in a container.

[0064] Referring again to FIG. 1, material handling system 10 may include a plurality of storage racks 20 that may be arbitrarily arranged to form rows or aisles 50 . For example, a first storage rack 20a may be spaced apart from a second storage rack 20b, forming an aisle 50 between the two storage racks. Specifically, the first storage rack 20a may be substantially parallel to the second storage rack 20b to form an aisle 50 having a substantially uniform width. Additionally, material handling system 10 may include multiple storage racks 20 forming multiple aisles 50 . The passages 50 may be arranged in a series of parallel rows. However, if the material handling system 10 incorporates multiple storage racks 20, the storage racks 20 may be arranged in a variety of configurations, and if the material handling system 10 includes multiple aisles 50, the aisles 50 need not be parallel.

[0065] Optionally, material handling system 10 includes automated elements for storing and retrieving totes 55 from storage locations 25 . One such automated element is a motor vehicle. For example, as described below, the automotive element may include multiple automotive vehicles 100. Additionally, the motor vehicles 100 may transport the totes 55 to a work site where one or more items may be configured to be retrieved from the totes 55 on any of the motor vehicles 100 . In one embodiment, a human operator or an automated mechanism may remove items from the vehicle 100 . Alternatively, as shown in FIGS. 1 and 4, the totes 55 may be transferred to a conveyor system at a transfer station 200 .

[0066] The material handling system 10 and / or various components of the material handling system 10 may be controlled by a central controller 90, such as a microcomputer. The central controller 90 may receive signals from various components, such as sensors, and control various functions of the material handling system 10 based on the signals received from the various components. The central controller 90 may also store data obtained from the material handling system 10 regarding the locations of various items. Additionally, central controller 90 may include data regarding the identity of the items to be obtained, such as the number of items to fulfill the customer's order and the quantity of those items. In this manner, the central controller 90 may control and coordinate the operation of the various components to schedule the retrieval and processing of various items from the storage locations 25.

[0067] As previously mentioned, the material handling system 10 may include one or more storage racks 20 having multiple storage locations 25 . Details of an exemplary storage rack 20 are shown in FIGS. However, material handling system 10 may include any of a variety of components that organize multiple storage locations 25 .

[0068] 2 and 3, each storage rack 20 may include a plurality of substantially vertically extending support legs and a plurality of substantially horizontally extending brackets interconnecting the support legs. The bracket may be a planar element that forms a shelf such that the shelf forms storage location 25 . However, in the embodiment shown in FIG. 2, the horizontal brackets are L-shaped brackets that form horizontal legs to support the edges of the tote 55. The horizontal brackets may be spaced apart from one another by the height of the vertical legs to form vertical rows 22 of vertically spaced apart storage locations 25 .

[0069] As previously mentioned, the material handling system 10 may include a plurality of spaced apart storage racks 20 to form one or more aisles 50 . Optionally, as shown in Figures 1 and 3, a track 40 may be positioned along one or more storage racks 20 and may be configured to vertically guide vehicles 100 up and down vertical rows 22 so that vehicles 100 are transported to storage locations 25 within vertical rows 22. Additionally, it may be desirable to position a first track along a storage rack on one side of aisle 50 (e.g., storage rack 20a) and a second track along a storage rack on the opposite side of aisle 50 (e.g., storage rack 20b). Vehicle 100 may be configured such that vehicle 100 moves vertically within aisle 50 along a track that is aligned with storage rack 20a while simultaneously moving vertically along a track that is aligned with storage rack 20b.

[0070] When the material handling system 10 uses one or more vehicles 100 and one or more storage racks 20, the storage racks 20 may be configured to allow the vehicles 100 to travel underneath the storage racks 20, as well as across or along aisles 50 that may be incorporated into the material handling system 10. Referring to FIG. 2, the vehicle 100 may follow a route along one or more segments that are parallel or perpendicular to the pathway 50 . For example, the first vehicle 100a is oriented for horizontal movement along a path perpendicular to the length of the passageway 50. The second vehicle 100b is oriented to travel horizontally beneath the storage racks 20 along a path parallel to the length of the aisle 50. Additionally, a third vehicle 100d is positioned within the aisle 50 so as to climb the vertical tracks 40 along the storage racks 20 on either side of the aisle 50. A fourth vehicle 100e is also positioned in aisle 50 and travels up tracks 40a and 40b to reach storage location 25 at the top of column 22. Finally, the fifth vehicle 100f is positioned below the storage rack 20 and faces in a direction midway between the direction that vehicles 100a and 100b are facing. In particular, the storage rack 20 may be configured to facilitate the vehicle 100 turning horizontally underneath the storage rack 20 . The fifth vehicle 100f shows the vehicle 100 in the process of turning from the first path to the second path under the storage rack 20.

[0071] 5-7 show details of one of the vehicles 100 shown in FIGS. 1-4. As previously mentioned, when material handling system 10 incorporates vehicle 100, the configuration of vehicle 100 may vary. Details of an exemplary haul vehicle 100 are disclosed in US Pat. No. 6,329,999. The disclosure of Patent Document 1 is incorporated herein by reference. However, each feature of the vehicle 100 described in Patent Document 1 or described below is optional and may be changed or omitted depending on the application.

[0072] The vehicle 100 may be an automotive system that includes an on-board power source that powers the vehicle 100 . Vehicles 100 may also include a communication system for wirelessly transmitting and receiving control signals between each vehicle 100 and a control element such as central controller 90 . In this manner, the vehicle 100 may receive control signals regarding where to pick up the item and where the vehicle 100 should deliver the item.

[0073] Central controller 90 may include any of a variety of control mechanisms, including, but not limited to, a central processing unit such as a microprocessor. Aspects of central controller 90 may be implemented in hardware and / or software (including firmware, resident software, microcode, etc.), generally referred to herein as "circuits" or "modules." Furthermore, the present invention may take the form of a computer program product on a storage medium usable by or readable by central controller 90 having program code usable by or readable by central controller 90. The program code is stored in the storage medium and is used by or connected to a command execution system. In this context, a medium usable by or readable by the central controller 90 may be any medium capable of containing, storing, communicating, transmitting, or transporting a program used in or connected to a command execution system, apparatus, or device. These computer program instructions may be stored in memory available to or readable by central controller 90 . This memory may cause the central controller 90 or other programmable data processing device to function in a particular manner. This produces a product whose instructions, stored in a memory usable by or readable by central controller 90, perform the functions specified in the flowcharts and / or block diagrams.

[0074] The medium usable by or readable by central controller 90 may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device. More specific examples (list) of media readable by the central control unit 90 include the following: hard disks, optical storage devices, magnetic storage devices, electrical connections having one or more wires, portable computer floppy disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, and compact disc read-only memory (CD-ROM).

[0075] Computer program code for carrying out operations of embodiments of the present invention may be written in an object oriented programming language such as Java, Smalltalk or C++. However, computer program code for carrying out operations of embodiments of the present invention may also be written in conventional procedural programming languages, such as the "C" programming language and / or any other lower level assembler language. It will be further understood that any or all of the functionality of the program modules may be implemented using discrete hardware components, one or more application specific integrated circuits (ASICs), or programmed digital signal processors or microcontrollers.

[0076] The vehicle 100 shown in FIG. 3 includes a horizontal drive mechanism 120 that drives the vehicle 100 in the horizontal direction. The horizontal drive mechanism 120 may be configured to drive the vehicle 100 along the track 40 or along a large horizontal surface such as a floor. For example, horizontal drive mechanism 120 options include multiple rotatable elements, such as wheels or rollers. One or more drive mechanisms may be provided to rotate such rotatable elements. Additionally, the rotatable elements may steer the vehicle 100 by turning left and right.

[0077] Alternatively, as shown in Figures 5 to 7, the vehicle 100 may have a horizontal drive mechanism 120 formed of a plurality of rollers 122, 123, 124 rotatable about a first axis, such as an axle. Additionally, rollers 122, 123, 124 may be constrained to rotate about a single axis. For example, in the embodiment shown in FIGS. 5-7, the horizontal drive mechanism 120 includes a pair of center rollers 124, a first set of outer rollers 122, and a second set of outer rollers 123. The first set of outer rollers 122 are positioned in front of the central roller 124 and the second set of outer rollers 123 are positioned behind the central roller 124 . The outer rollers 122, 123 may include multiple rollers spaced apart along the length of the horizontal axis, and each set of outer rollers 122, 123 may include a first roller 122a on one side of the vehicle 100 and a second roller 122b on the opposite side of the vehicle 100, as shown in FIG. 6. Additionally, as shown in FIG. 6, each set of outer rollers may include a pair of rollers 122b on each side of the vehicle 100.

[0078] As previously mentioned, the vehicle 100 may have any of a variety of steering mechanisms for controlling the direction of travel of the vehicle 100 . For example, one steering mechanism option is a zero-turn mechanism that allows the vehicle 100 to turn without substantially moving forward. Optionally, the zero-turn mechanism has the ability to turn the vehicle 100 around a vertical axis passing through the vehicle 100 .

[0079] The zero-turn mechanism includes a linkage mechanism that allows the wheels or rollers on one side of the vehicle 100 to turn at a different speed than the wheels or rollers on the opposite side of the vehicle 100 . Optionally, the linkage allows the wheels or rollers on one side of the vehicle 100 to rotate in a different direction than the wheels or rollers on the opposite side of the vehicle 100 . In this manner, by varying the speed and / or direction of rotation of the wheels on one side of the vehicle 100 relative to the speed and / or direction of rotation of the wheels on the opposite side of the vehicle 100, the zero-turn mechanism changes direction of travel and steers the vehicle 100. Optionally, the material handling system 10 may include one or more guide members 80 that guide or align the vehicle 100 as it moves, and the vehicle 100 may include guide member elements that cooperate with the guide members 80 to align and / or guide the vehicle 100.

[0080] In addition to the horizontal drive mechanism 120 , the vehicle 100 may also include a vertical drive mechanism 140 that drives the vehicle 100 vertically within the storage rack 20 . Specifically, as previously mentioned, material handling system 10 may include a guide mechanism, such as track 40 , disposed adjacent storage rack 20 . The vertical drive mechanism 140 may be configured to cooperate with the vertical guide mechanism 40 to drive the vehicle 100 vertically.

[0081] 5-6 illustrate an exemplary vertical drive mechanism 140 that includes a plurality of rotatable drive gears 145. However, it should be understood that vertical drive mechanism 140 may include any of a number of drive mechanisms for driving vehicle 100 vertically. Referring to FIG. 5, vertical drive mechanism 140 may include a drive gear 145 that rotates about a horizontal axis that is perpendicular to the horizontal axis of rotation of horizontal drive mechanism 120 . Specifically, optionally, vehicle 100 includes a pair of spaced apart drive gears 145, with the teeth of a first gear 145b projecting outward from a first side of vehicle 100 and the teeth of a second gear 145d projecting outward from a second side of vehicle 100, as shown in FIG. 6 . The first gear 145b and the second gear 145d may be driven synchronously. Additionally, as shown in FIG. 5, the vehicle 100 may include two pairs of vertical drive elements 145 spaced apart along the length of the vehicle 100. Specifically, optionally, vehicle 100 includes a first pair of vertical drive elements 145a, 145c at a first end of vehicle 100 and a second pair of vertical drive elements 145b, 145d at a second end of vehicle 100.

[0082] 1-3, the storage racks 20 may be configured such that the track 40a along a first storage rack 20a is spaced from the track 40b along a second storage rack 20b by a distance corresponding to the spacing between the first set of vertical drive elements 145a and the second set of vertical drive elements 125b. In this manner, the first vertical drive element 145a may cooperate with the first track 40a to drive the vehicle 100 up the first track 40a, while the second vertical drive element 145b may cooperate with the second track 40b to drive the vehicle 100 up the second track 40b. Optionally, the two vertical drive elements 145a, 145b are driven synchronously so that the vehicle 100 maintains a horizontal orientation as it moves from horizontal to vertical motion.

[0083] Vertical drive mechanism 140 may optionally be configured so that the width of vertical drive mechanism 140 remains substantially constant as vehicle 100 transitions from horizontal to vertical movement. In this way, the vertical drive mechanism 140 does not need to narrow or expand outward in width to transition from horizontal drive to vertical drive. For example, referring to Figures 5 and 6, front elevation gears 145b and 145d each have a horizontal axis of rotation, and the horizontal axis of rotation of drive member 145b is fixed relative to the horizontal axis of rotation of drive member 145d while vehicle 100 is moving horizontally and while vehicle 100 is ascending.

[0084] Vehicle 100 may also include an optional transport mechanism for transporting items between vehicle 100 and a destination such as storage location 25 . The transfer mechanism 150 may operate to transfer items between the loading surface of the vehicle 100 and one of a plurality of destination areas 25 . Optionally, a loading surface is defined by the outer surfaces of a number of rollers, as shown in FIG.

[0085] The transfer mechanism 150 may be any of a variety of mechanisms for loading items onto the vehicle 100 and unloading items from the vehicle 100 into one of the storage areas. Additionally, the transport mechanism 150 may be specially adapted for a particular application. In this embodiment, the transport mechanism 150 includes one or more displaceable elements that engage items stored in the storage locations 25 and pull the items onto the vehicle 100 . More specifically, in this embodiment, vehicle 100 includes one or more displaceable elements that move toward and releasably engage tote 55 within storage location 25 . After the displaceable elements engage the tote 55 , each displaceable element moves away from the storage location 25 , thereby pulling the tote 55 onto the vehicle 100 .

[0086] The displaceable element of the transfer mechanism 150 may be any of a variety of items, such as a bar, rod, or another element that engages an item, such as a tote 55 . For example, with reference to FIGS. 5 and 6, the transport mechanism 150 may include one or more displaceable pins 152 . Additionally, the transport mechanism 150 may include a drive element that displaces the pin 152 . For example, the transport mechanism 150 optionally includes two drive elements in the form of an endless carrier, such as a drive belt or drive chain 154 . Optionally, each pin 152 protrudes or extends inwardly toward the longitudinal centerline of the vehicle 100 . The transfer mechanism 150 preferably cooperates with one of the totes 55 to releasably engage the tote 55 . For example, in this embodiment, pin 152 fits into a recess in tote 55 so that transfer mechanism 150 can engage tote 55 . However, the transfer mechanism 150 may include any of a variety of elements that engage with items being loaded onto or unloaded from the vehicle 100.

[0087] Referring to FIGS. 1 and 4, a material handling system 10 includes an input / output station where containers are loaded onto or unloaded from a vehicle 100 . For example, containers may be loaded onto vehicle 100 to replenish the inventory of items stored in the racking system. In such applications, a conveyor system 300 may automatically transport containers 55 to an input / output station 200 where the containers are loaded onto vehicles 100 . The vehicle 100 then transports the container 55 to the storage rack 20 and transfers the container 55 to the storage location 25. Alternatively, the vehicle 100 may retrieve the container 55 from the storage location 25 of the storage rack 20 and transport the container 55 to the input / output station 200 where the container 55 is transferred. The container 55 may then be automatically transported by the conveyor system 300 for downstream processing. For example, at a downstream work station, an operator may retrieve one or more items from container 55 .

[0088] Optionally, the conveyor system 300 may include one or more transport systems forming a circular path that allows the containers 55 to be transported from the input / output station 200 of the transfer station and then returned to the input / output station 200. As such, the conveyor system 300 may include one or more forward sections that transport the containers 55 away from the input / output station 200 and one or more return sections that transport the containers 55 toward the input / output station 200. The aforementioned downstream stations may be located along either the forward section or the return section.

[0089] The input / output station 200 includes one or more transfer stations 230 that transfer containers 55 between the input / output station 200 and the vehicles 100 . In the embodiment shown in FIGS. 1 and 4, the material handling system 10 includes multiple loading stations 230. For example, the input / output station 200 may include a pair of transfer conveyors 210 consisting of second and third horizontal conveyors spaced apart from each other, and each transfer conveyor 210 may include one or more transfer stations 230. In this embodiment, each transfer conveyor 210 includes multiple transfer stations 230 .

[0090] The input / output station 200 may incorporate a single transfer conveyor 210, but in this embodiment includes a pair of conveyors. The transfer conveyor 210 may be configured in a variety of configurations. For example, the transfer conveyors 210 may be positioned at an angle relative to one another. Alternatively, in the illustrated embodiment, the transfer conveyors 210 are spaced apart and substantially parallel to one another. The gap formed between the pair of transfer conveyors 210 may form a passage 220 along which the transport vehicle 100 travels, as will be described later.

[0091] Referring to FIG. 4, each transfer conveyor 210 may include multiple stack conveyors. For example, as shown, each transfer conveyor 210 includes multiple levels, each level being an independent conveyor that overlaps with the conveyor below. For example, the transfer conveyor 210 on one side of the aisle 220 may include three levels, designated 210A, 210B, and 210C. Similarly, the first horizontal conveyor, main conveyor 300, includes multiple levels 300A, 300B and 300C, each aligned with a corresponding level of each of the transfer conveyors, such as transfer conveyors 210A, 210B and 210C. Although the main conveyor 300 and the transfer conveyor 210 are shown as having three levels, it should be understood that the main conveyor 300 and the transfer conveyor 210 may have any number of levels depending on the application.

[0092] Referring to FIG. 1, each of the second and third horizontal conveyors 210 may include multiple loading stations 230 spaced along the length of the transfer conveyor 210. For example, each transfer conveyor 210 may include two loading stations 230 . Additionally, as shown in FIG. 4, each level of the transfer conveyor 210A, 210B or 210C may have multiple loading stations. For example, transfer conveyor 210A may include transfer stations 230A and 230H. Thus, each transfer conveyor 230 may have multiple overlapping transfer stations 230, such as 230A, 230B and 230C, or 230D, 230E and 230F.

[0093] As mentioned above, each haul vehicle 100 may include a transfer mechanism 150 operable to transfer items, such as totes 55 , to the transfer conveyor 210 at the loading station 230 . Additionally, as shown in FIGS. 1 and 4, the loading station 230 may include a loading mechanism 235 operable to load items onto the transfer conveyor 210. Specifically, the loading mechanism 235 moves items in a direction perpendicular to the direction of movement of the items on the transfer conveyor 210 . For example, as shown in FIG. 1, the transfer conveyor 210 may operate to move items in a first direction indicated as T2. Similarly, the transfer conveyor 210 may operate to move items in the opposite direction, indicated at T3 in FIG. The loading mechanism 235 may be configured to load items onto the transfer conveyor 210 by moving the items in a direction perpendicular to T2 or T3. For example, the loading mechanism 235 may move the item in a direction parallel to T1.

[0094] The loading mechanism 235 may be made up of any of a variety of components that transport items across a conveyor. For example, the loading mechanism 235 may be a right-angle transfer mechanism. Specifically, the loading mechanism 235 may be one or more conveyor belts wrapped around a number of rollers or pulleys. The conveyor belt may extend in a direction opposite to the direction of travel T2, T3.

[0095] The loading mechanism 235 may be movable between a first position and a second position, where in the first position the loading mechanism 235 is hidden from or out of the path of travel of the transfer conveyor 210. In this manner, in the first position, the loading mechanism 235 does not impede movement along the transfer conveyor 210, for example, movement along the longitudinal direction of the transfer conveyor 210 (eg, direction T2 or T3). In the second position, the loading mechanism 235 may prevent movement along the length of the transfer conveyor 210 .

[0096] As an example, the loading mechanism 235 may be a conveyor disposed between the rollers of the transfer conveyor 210, which is the second and third horizontal conveyor. The loading mechanism 235 may be movable between a first position and a second position. In this first position, the loading mechanism 235 is positioned below the upper surface of the rollers of the transfer conveyor 210, and items such as totes 55 may move freely along the length of the transfer conveyor 210 toward the main conveyor 300 or one of the loading stations 230 (i.e., in direction T2 or T3). In the second position, the loading mechanism 235 is disposed in an upward position, and the upper surface of the loading mechanism 235 is raised above the transfer conveyor 210. In this manner, the loading mechanism 235 may prevent movement of items along the length of the transfer conveyor 210 . Additionally, in the upper position, the loading mechanism 235 can move items onto the transfer conveyor 210 while the transfer conveyor 210 is able to move items.

[0097] Although the loading mechanism 235 is described as being a right-angle conveyor having an upper position in which the loading mechanism 235 is operable and a lower position in which the loading mechanism is retracted or retracted, it should be understood that the loading mechanism 235 may be any of a variety of mechanisms for moving items across the width of a conveyor.

[0098] Transfer station 200 may optionally include a charging mechanism for charging vehicle 100 . The charging mechanism may be connected to a power source to provide a charging current to recharge the power source of the vehicle 100 . For example, optionally, each vehicle 100 includes a rechargeable on-board power source. The rechargeable on-board power source may be a rechargeable battery. However, in this embodiment, the vehicle 100 is equipped with a power source that includes multiple ultracapacitors that are capable of being rapidly recharged. For example, the power source may include a number of supercapacitors or ultracapacitors sufficient to power the vehicle 100 as it moves horizontally or vertically with a payload of 30 to 40 kilograms.

[0099] The charging mechanism may be any of a variety of components that provide charging current to the vehicle 100 . For example, in this embodiment, the charging mechanism may be a charging rail that cooperates with electrical contacts on the vehicle 100 .

[0100] The charging rail 340 may include one or more elongated conductive elements. The charging rail 340 may form one or more channels or grooves that cooperate with electrical contacts on the vehicle 100 . For example, the vehicle 100 may include one or more charging contacts, such as brushes. The brushes may protrude outwardly from the vehicle 100 . The brushes are oriented and configured to mate or cooperate with the charge rail 340 . For example, the charging rail 340 may be oriented horizontally and project horizontally outward from the rear side of the vehicle 100 so that the brushes project and make electrical contact with the charging rail 340 when the vehicle 100 is in transit.

[0101] The material handling system 10 and various sub-mechanisms described above may be configured to facilitate numerous methods of operation related to material handling, as described below.

[0102] The material handling system 10 may include a plurality of motor vehicles 100 that transport items to a transfer station 230 . The vehicle 100 may be configured to be driven along a horizontal path 60, such as the ground. Optionally, the vehicle 100 may be driven along the ground to a storage area where multiple items are stored. For example, multiple items may be stored in multiple containers such as totes 55 . Optionally, the totes 55 may be stored in a plurality of spaced apart storage racks 20 forming a longitudinally elongated aisle 50 . The passages 50 may be parallel to one another.

[0103] The vehicle 100 may be driven under one of the storage racks 20 in a direction parallel to one of the aisles 50 . The vehicle 100 may drive under the storage rack 20 until it reaches the desired vertical row 22 within the storage rack 20 where it will store or retrieve an item.

[0104] Optionally, once the vehicle 100 reaches the destination vertical column 22, it may turn or swerve to change direction. For example, while the vehicle 100 is in the destination vertical row 22 , the vehicle 100 may change direction from traveling parallel to the aisle 50 to traveling perpendicular to the aisle 50 . Alternatively, the vehicle 100 may be driven under the storage rack 20 to the destination vertical row 22 along a path that is substantially perpendicular to the aisle 50 . After reaching the destination vertical row 22, the vehicle 100 optionally moves in a direction perpendicular to the aisle 50 to move into the aisle 50 of the destination vertical row 22.

[0105] In the aisle 50, the vehicle 100 optionally travels up to a destination 25 where an item is stored or retrieved. Vehicle 100 may be lifted above vertical column 22 by an elevator or other mechanism. However, in this embodiment, the vehicle 100 includes a vertical drive mechanism 140 operable to drive the vehicle 100 upward. Additionally, the material handling system 10 may include a track or guide member 40 positioned adjacent to the vertical column 22, and a vertical drive mechanism 140 of the vehicle 100 may engage the track or guide member 40 to drive the vehicle 100 up the vertical column 22 to its destination.

[0106] Once the vehicle 100 is lifted to the destination, items such as totes 55 may be transferred between the vehicle 100 and the destination. For example, the vehicle 100 may include a transfer mechanism 150 that transfers the tote 55, and the vehicle 100 may operate the transfer mechanism 150 to transfer the tote 55 from the vehicle 100 to a destination or to transfer the tote 55 from the destination to the vehicle 100.

[0107] After transferring the items between the vehicle 100 and the destination, the vehicle 100 optionally drives downward to a horizontal path 60, such as the ground. The vehicle 100 may then be driven horizontally along a path perpendicular to the pathway 50 .

[0108] The material handling system 10 may also include one or more transfer stations 200 . The material handling system 10 may include a method for operating the automotive vehicle 100 at the work site 200 . For example, vehicle 100 may travel along a horizontal path transporting items such as totes 55 to transfer station 200 . The vehicle 100 may be moved to a transfer station and the vehicle 100 may be aligned in a predetermined position within the work station.

[0109] The material handling system 10 may optionally include a method for controlling the vehicle 100 to transfer items, such as totes 55 , at the transfer station 200 . For example, the method of controlling the vehicle 100 may include driving the vehicle 100 into the transfer station 200 and lifting the vehicle 100 upward. For example, the vehicle 100 may be lifted upwardly towards the transfer conveyor 210 . Optionally, the input / output station 200 may include one or more transfer stations 230, and the method of controlling the vehicle 100 may include lifting the vehicle 100 so that the tote 55 on the vehicle 100 is placed at the transfer station 230.

[0110] Optionally, lifting the vehicle 100 may include driving the vehicle 100 up the track 250 . The track 250 may include a first pair of spaced apart track segments and a second pair of spaced apart aft track segments. The method of controlling vehicle 100 may include driving the rear end of vehicle 100 over a rear track segment and the front end of vehicle 100 over a front track segment. For example, as shown in FIG. 4, vertical track 250 may be located adjacent to transfer station 230. A pair of rear tracks may be located on one side of aisle 220 adjacent to loading stations 230D, 230E, and 230F, and a pair of front tracks may be located on the other side of aisle 220 adjacent to loading stations 230A, 230B, and 230C. In this manner, the haul vehicle 100 may move vertically within the aisle 220 to align the haul vehicle 100 with one of the loading stations.

[0111] Optionally, the step of driving the vehicle 100 up the track 250 may include the step of rotating a vertical drive gear 145 of the vehicle 100 around an axis that is perpendicular to the rotation axes of the multiple drive elements that drive the vehicle 100 along the horizontal plane. Driving the vehicle 100 up the track 250 may optionally include driving the vertical drive gear 145 in a first direction up the track 250 by driving the vertical drive gear 145 in a first direction. Driving the vertical gear in a first direction drives the vertical drive gear 145 up the track 250 .

[0112] The method may also include transferring items between the haul vehicle 100 and the loading station 230 after the haul vehicle 100 is aligned with the loading station 230 . The step of transferring the items may include a step of operating a transfer mechanism 150 on the transport vehicle 100 to move the items between the transport vehicle 100 and the loading station 230 by operating a transfer mechanism 150 on the transport vehicle 100. Additionally, transferring the item may include activating a transfer mechanism at input / output station 200 . For example, the step of transferring the item may include driving the transfer mechanism 150 of the transport vehicle 100 to move the container 55 from the vehicle 100 toward the loading station 230. Once a portion of the container 55 has been loaded into the loading station 230 , the loading mechanism 235 may move the container 55 across the width of the transfer conveyor 210 and load the container 55 onto the transfer conveyor 210 . Similarly, the method may include a step of loading a container 55 onto the transport vehicle 100 by operating a loading mechanism 235 to load the container 55 onto the transport vehicle 100, thereby moving the container 55 across the width of the transfer conveyor 210 toward the transport vehicle 100. Next, the transfer mechanism 150 of the transport vehicle 100 is operated to load the container 55 onto the transport vehicle 100 .

[0113] Operating the loading mechanism 235 may include lifting the loading mechanism 235 above the upper surface of the transfer conveyor 210 .

[0114] The step of transferring the container 55 between the transport vehicle 100 and the transfer conveyor 210 may include both operating the transfer mechanism 150 on the transport vehicle 100 and operating the loading mechanism 235, although it should be understood that the method is not limited to using both the transfer mechanism 150 on the transport vehicle 100 and a separate loading mechanism 235 on the input / output station 200. Alternatively, the transfer mechanism 150 on the transport vehicle 100 may be configured to move the container 55 across the width of the transfer conveyor 210 . Alternatively, the loading mechanism 235 may be configured to engage the container 55 such that the loading mechanism 235 may load or unload the container 55 onto or from the transport vehicle 100 without operating the transfer mechanism 150 on the transport vehicle 100.

[0115] As shown in Figures 1 and 4, the method may include transferring items between a main conveyor 300, which is a first horizontal conveyor that moves items in a first direction, such as T1, and a transfer conveyor 210, which is a second or third horizontal conveyor that moves items in a second direction, such as T2 or T3, that is perpendicular to T1. Transferring items between the main conveyor 300 and the transfer conveyor 210 may include operating the right-angle transfer mechanism 320 . The right-angle transfer mechanism 320 may be configured similarly to the loading mechanism 235 described above.

[0116] As mentioned above, the method may include transferring containers 55 between input / output station 200 and main conveyor 300 . For example, transferring the container 55 may include conveying the container 55 along a first path of the input / output station 200 toward the main conveyor 300 . The method may include the step of operating a right-angle transfer mechanism to move the container 55 onto the main conveyor 300.

[0117] The method may optionally include the step of transporting the container 55 from the input / output station 200 . For example, this may include transporting the container 55 from the input / output station 200 along one or more conveyor sections. Optionally, the method may include conveying the container 55 toward the input / output station 200 after conveying the container 55 from the input / output station 200 along one or more conveyor sections. Thus, the method may include transporting the container 55 from the input / output station 200 along a circular path and back to the input / output station 200 . The method may also include transporting the container 55 along a circular path to a work site so that an operator can load items into the container 55 or retrieve items from the container 55.

[0118] The material handling system 10 may optionally include a method for charging the automated material handling vehicle 100 . The method of charging the vehicle 100 may then include driving the vehicle 100 to the input / output station 200 to transport the item. The vehicle 100 may include electrical contacts 160 and the input / output station 200 may include charging elements that provide a charging current. The method of charging the vehicle 100 may include electrically connecting the electrical contacts 160 of the vehicle 100 to a charging element. For example, electrically connecting may include biasing the charging element toward charging contact 160 and / or biasing charging contact 160 toward the charging element.

[0119] Additionally, the electrically connecting step may include driving the vehicle 100 toward the charging element, thereby electrically connecting the electrical contacts 160 to the charging element. Optionally, the charging method includes automatically adjusting the height of the charging element relative to the charging contacts as the charging contacts move into electrical engagement with the charging element. Additionally, the charging method may include automatically adjusting the lateral position of the charging contacts relative to the charging element 340 as the charging contacts move into electrical engagement with the charging element.

[0120] The method of charging the vehicle 100 may optionally include the step of vertically lifting the vehicle 100 while continuing to charge the vehicle 100. For example, the charging method may include maintaining an electrical connection between the electrical contacts 160 of the vehicle 100 and the charging element while the vehicle 100 is moving upward. Additionally, charging current may be continuously supplied to charging element 340 as vehicle 100 moves upward at station 200 . Alternatively, charging current may be maintained to the charging element while the vehicle 100 is at the loading station 230 so that charging current is supplied to the vehicle 100 while the transfer mechanism 150 is transferring items to or from the vehicle 100. Charging current may be supplied to the vehicle 100 while the vehicle 100 is being lowered. The method of charging the vehicle 100 may optionally include the step of decoupling the vehicle 100 from the charging element by driving the vehicle 100 away from the charging element.

[0121] It should also be understood that the invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as set forth in the claims.

Claims

1. 1. A material handling system comprising: a plurality of storage locations vertically spaced apart from one another; a track disposed adjacent to the plurality of storage locations; a plurality of containers disposed at said plurality of storage locations; A plurality of vehicles transporting the plurality of containers, each vehicle comprising: and each vehicle is operable to retrieve one of the plurality of containers from one of the plurality of storage locations or store one of the plurality of containers in one of the plurality of storage locations; a drive mechanism for driving and positioning each of the vehicles along the track to a first storage location of the plurality of containers for retrieving a first of the plurality of containers from the first storage location of the plurality of storage locations; and a power source for providing power to the drive mechanism. a plurality of vehicles, a first horizontal conveyor configured to receive the plurality of containers and transport the plurality of containers along a first horizontal path to a work station where an operator can retrieve one or more items from the plurality of containers, the first horizontal path being in a first direction; a transfer station that receives a plurality of containers from the plurality of vehicles and transports the plurality of containers toward the first horizontal conveyor, the transfer station comprising: a second horizontal conveyor that moves the plurality of containers toward the first horizontal conveyor along a second horizontal path, the second horizontal path being perpendicular to the first horizontal path; a guide member for guiding the plurality of vehicles from a horizontal surface to a first transfer location disposed along the second horizontal conveyor, the drive mechanism being operable to transfer the first container from a first vehicle onto the second horizontal conveyor at the first transfer location; a transfer station including: A material handling system comprising:

2. 10. The material handling system of claim 1, wherein the plurality of storage locations are arranged in a series of columns or in a series of vertically spaced rows.

3. 3. A material handling system according to claim 1 or claim 2, comprising one or more transfer locations spaced vertically from the first transfer location.

4. 4. The material handling system of claim 3, wherein said guide member includes a first track that guides said plurality of vehicles from said horizontal surface to one of said one or more transfer locations.

5. 5. The material handling system of claim 4, wherein the first track of the guide member includes a first vertical track that cooperates with the drive mechanism to drive the vehicle upwardly to one of the one or more transfer locations.

6. the transfer station includes a third horizontal conveyor spaced apart from the second horizontal conveyor; 6. The material handling system of claim 1, wherein the third horizontal conveyor forms a path with the second horizontal conveyor to move a plurality of containers along a third horizontal path toward the first horizontal conveyor.

7. the transfer station includes a second vertical track adjacent to the third horizontal conveyor; 7. The material handling system of claim 6, wherein the second vertical track cooperates with the drive mechanism to drive the vehicle upwardly within the path between the second horizontal conveyor and the third horizontal conveyor.

8. each vehicle including a transfer mechanism that engages the plurality of containers; 8. A material handling system as claimed in any one of claims 1 to 7, wherein the transfer mechanism transfers the plurality of containers between the vehicle and the plurality of storage locations.

9. 9. The material handling system of claim 8, wherein the transfer mechanism transfers the first container from the first vehicle toward the second horizontal conveyor.

10. 10. The material handling system of claim 8 or claim 9, wherein the transfer mechanism moves the first container in a direction perpendicular to the second horizontal path when the first vehicle moves the first container toward the second horizontal conveyor.

11. the first horizontal conveyor includes a plurality of vertically spaced, overlapping conveyors forming a plurality of conveyor tiers; the second horizontal conveyor includes a plurality of vertically spaced, overlapping conveyors; 11. A material handling system as claimed in any one of claims 1 to 10, wherein each of the overlapping conveyors of the second horizontal conveyor intersects with one of the conveyor levels of the first horizontal conveyor.

12. 12. A material handling system according to any preceding claim, wherein each vehicle includes a surface for supporting one of the plurality of containers.

13. 13. A material handling system according to any preceding claim, comprising a central controller for controlling the operation of each of the plurality of vehicles.

14. 14. A material handling system according to any preceding claim, wherein the drive mechanism comprises one or more rotatable elements.

15. 15. The material handling system of claim 14, wherein the rotatable element is a wheel or a roller.

16. 16. A material handling system according to any preceding claim, wherein the power source is rechargeable.

17. the drive mechanism includes a horizontal drive mechanism and a vertical drive mechanism; the horizontal drive mechanism drives the vehicle along the horizontal plane; the vertical drive mechanism drives the vehicle vertically along the track; the first storage location is located above the horizontal surface; 17. A material handling system according to any preceding claim, wherein the vertical drive mechanism drives the vehicle upwardly towards the first storage location.

18. 18. The material handling system of claim 1, wherein the first horizontal conveyor includes a circular path having a first section for moving the plurality of containers from the transfer station and a second section for moving the plurality of containers to the transfer station.

19. 1. A method for storing or retrieving a plurality of containers at a plurality of storage locations in one or more storage racks, comprising: controlling a plurality of independently operable vehicles to deliver a plurality of containers to or retrieve a plurality of containers from the plurality of storage locations, the step of controlling a plurality of independently operable vehicles comprising: driving a first vehicle of the plurality of independently operable vehicles along a horizontal plane toward one of the one or more storage racks; moving the first vehicle upward from the horizontal surface to one of the plurality of storage locations, thereby aligning the first vehicle with a first container of the plurality of containers; controlling a plurality of independently operable vehicles, driving the first vehicle with the first container along the horizontal plane between the storage rack and a transfer station; moving the first vehicle vertically between the horizontal surface and a transfer location at the transfer station; transferring the first container between the first vehicle and a first horizontal conveyor at the transfer station; controlling the first horizontal conveyor to transport the first container from the transfer location to the work site or from the work site to the transfer location; obtaining one or more items from the first container at the work site or storing one or more items in the first container at the work site; How to store or retrieve multiple containers, including:

20. 20. The method of storing or retrieving a plurality of containers as set forth in claim 19, wherein said step of moving said first vehicle vertically between said horizontal surface and a transfer location includes driving said first vehicle vertically over a guide member adjacent to said transfer location.

21. 21. A method of storing or retrieving a plurality of containers as described in claim 19 or claim 20, wherein the step of transferring the first container comprises moving the first container in a first direction toward the first horizontal conveyor.

22. 22. The method of storing or retrieving a plurality of containers of claim 21, wherein the step of controlling the first horizontal conveyor includes the step of transporting the first container along the first horizontal conveyor in a second direction that is perpendicular to the first direction.

23. transferring the first container from the first horizontal conveyor to a second horizontal conveyor capable of transporting the first container to the work station; 23. The method of storing or retrieving a plurality of containers of claim 22, wherein the second conveyor transports the first container in a third direction that is orthogonal to the second direction.

24. the step of transporting the first container further comprises: transporting the first container along a conveyor loop extending from the transfer station to the work station; returning the first container along the conveyor loop to the transfer station; 24. A method for storing or retrieving a plurality of containers according to any one of claims 19 to 23, comprising:

25. 25. The method of storing or retrieving a plurality of containers of any one of claims 19 to 24, including the step of charging the first vehicle during the step of moving the first vehicle vertically between the horizontal surface and a transfer location.

26. the step of transferring the first container between the first vehicle and a first horizontal conveyor comprises moving the first container onto a transfer mechanism; 26. A method of storing or retrieving a plurality of containers as claimed in any one of claims 19 to 25, comprising the step of moving the first container onto a transfer mechanism, the transfer mechanism being operable between a first position in which the transfer mechanism is disposed at a lower position below the first horizontal conveyor and a second position in which the transfer mechanism is disposed above the first horizontal conveyor.

27. 27. The method of storing or retrieving a plurality of containers of claim 26, wherein the step of moving the first container onto a transfer mechanism includes the step of moving the first container onto the transfer mechanism while the transfer mechanism is in the first position.

28. 28. The method of storing or retrieving a plurality of containers of claim 27, including the step of moving the transfer mechanism to the second position engaging the transfer mechanism with the first container.

29. 30. The method of storing or retrieving a plurality of containers of claim 28, comprising the step of operating the transfer mechanism to move the first container across the width of the first horizontal conveyor.

30. 30. The method of storing or retrieving a plurality of containers of claim 29, including the step of lowering the transfer mechanism after the step of actuating the transfer mechanism.

31. 31. The method of storing or retrieving a plurality of containers of claim 30, wherein the step of transporting the first container from the transfer location occurs after the step of lowering the transfer mechanism.

32. the first vehicle includes a transfer mechanism operable to transfer a plurality of containers onto and off the first vehicle; 32. A method of storing or retrieving a plurality of containers as described in any one of claims 19 to 31, wherein the step of transferring the first container between the first vehicle and a first horizontal conveyor includes the step of operating the transfer mechanism.

33. 1. A transfer station for a material handling system storing a plurality of containers, comprising: a plurality of vehicles, each vehicle including a horizontal drive mechanism for driving each vehicle along a horizontal plane and a vertical drive mechanism for driving each vehicle vertically; a first horizontal conveyor having a loading station, the first horizontal conveyor operable in a first direction to move items from the loading station; a first track disposed adjacent to the loading station and operable to cooperate with the vertical drive mechanisms of the plurality of vehicles to move the front ends of the plurality of transport vehicles; a second track spaced apart from the first track and operable to cooperate with the vertical drive mechanisms of the plurality of transport vehicles to move the rear ends of the plurality of transport vehicles; A transfer station for a material handling system comprising:

Images