Vertical conveyor system

CROSS REFERENCE TO RELATED APPLICATIONS

0001This application claims the benefit of United States Provisional Patent Application Number <patcit id="pcit0001" dnum="US61168349B"><text>61/168,349 filed on April 10, 2009</text></patcit>, the disclosure of which is incorporated herein by reference in its entirety.

0002This application is related to United States Patent Application Number <patcit id="pcit0002" dnum="US12757381B"><text>12/757,381</text></patcit>, entitled "STORAGE AND RETRIEVAL SYSTEM," filed on April 9, 2010 with Attorney Docket Number 1127P013678-US (PAR); United States Patent application <patcit id="pcit0003" dnum="US12757337B"><text>12/757,337</text></patcit>, entitled "CONTROL SYSTEM FOR STORAGE AND RETRIEVAL SYSTEMS," filed on April 9, 2010 with Attorney Docket Number 1127P013888-US (PAR); United States Patent Application Number <patcit id="pcit0004" dnum="US12757220B"><text>12/757,220</text></patcit>, entitled "STORAGE AND RETRIEVAL SYSTEM," filed on April 9, 2010 with Attorney Docket Number 1127P013867-US (PAR); United States Patent Application Number <patcit id="pcit0005" dnum="US12757354B"><text>12/757,354</text></patcit>, entitled "LIFT INTERFACE FOR STORAGE AND RETRIEVAL SYSTEMS," filed on April 9, 2010 with Attorney Docket Number 1127P013868-US (PAR); and United States Patent Application Number <patcit id="pcit0006" dnum="US12757312B"><text>12/757,312</text></patcit>, entitled "AUTONOMOUS TRANSPORTS FOR STORAGE AND RETRIEVAL SYSTEMS," filed on April 9, 2010 with Attorney Docket Number 1127P013869-US (PAR), the disclosures of which are incorporated by reference herein in their entireties.

BACKGROUND

1. Field

0003The exemplary embodiments generally relate to material handling systems and, more particularly, to automated storage and retrieval systems.

2. Brief Description of Related Developments

0004Warehouses for storing case units may generally comprise a series of storage racks that are accessible by transport devices such as, for example, fork lifts, carts and elevators that are movable within aisles between or along the storage racks or by other lifting and transporting devices. These transport devices may be automated or manually driven. Generally the case units stored on the storage racks are contained in carriers, for example storage containers such as trays, totes or shipping cases, or on pallets. Generally, incoming pallets to the warehouse (such as from manufacturers) contain shipping containers (e.g. cases) of the same type of goods. Outgoing pallets leaving the warehouse, for example, to retailers have increasingly been made of what may be referred to as mixed pallets. As may be realized, such mixed pallets are made of shipping containers (e.g. totes or cases such as cartons, etc.) containing different types of goods. For example, one case on the mixed pallet may hold grocery products (soup can, soda cans, etc.) and another case on the same pallet may hold cosmetic or household cleaning or electronic products. Indeed some cases may hold different types of products within a single case. Conventional warehousing systems, including conventional automated warehousing systems do not lend themselves to efficient generation of mixed goods pallets. In addition, storing case units in, for example carriers or on pallets generally does not allow for the retrieval of individual case units within those carriers or pallets without transporting the carriers or pallets to a workstation for manual or automated removal of the individual case units.

0005It would be advantageous to have a storage and retrieval system for efficiently storing and retrieving individual case units without containing those case units in a carrier or on a pallet.

BRIEF DESCRIPTION OF THE DRAWINGS

0006The foregoing aspects and other features of the disclosed embodiments are explained in the following description, taken in connection with the accompanying drawings, wherein:

0007<figref idref="f0001">Fig. 1</figref> schematically illustrates an exemplary storage and retrieval system in accordance with an exemplary embodiment;

0008<figref idref="f0002">Fig. 2</figref> illustrates a schematic plan view of a storage and retrieval system in accordance with the exemplary embodiments;

0009<figref idref="f0003">Fig. 5</figref> illustrates a structural portion of a storage and retrieval system in accordance with an exemplary embodiment;

0010<figref idref="f0004 f0005">Figs. 7A-7D</figref>, <figref idref="f0006">8A and 8B</figref> illustrate schematic views of a conveyor system in accordance with an exemplary embodiment;

0011<figref idref="f0007">Fig. 9</figref> illustrates a schematic view of a conveyor shelf in accordance with an exemplary embodiment;

0012<figref idref="f0007">Fig. 10</figref> schematically illustrates a conveyor system in accordance with an exemplary embodiment;

0013<figref idref="f0008 f0009">Figs. 11A-11D</figref> schematically illustrate a transfer station in accordance with an exemplary embodiment;

0014<figref idref="f0010">Fig. 12</figref> illustrates a portion of a transfer arm of a transport robot in accordance with an exemplary embodiment;

0015<figref idref="f0011">Fig. 13</figref> is a schematic illustration of a method in accordance with an exemplary embodiment; and

0016<figref idref="f0012 f0013">Figs. 14-15</figref> are flow diagrams of exemplary methods in accordance with the exemplary embodiments.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENT(S)

0017<figref idref="f0001">Fig. 1</figref> generally schematically illustrates a storage and retrieval system 100 in accordance with an exemplary embodiment. Although the embodiments disclosed will be described with reference to the embodiments shown in the drawings, it should be understood that the embodiments disclosed can be embodied in many alternate forms. In addition, any suitable size, shape or type of elements or materials could be used.

0018In accordance with one exemplary embodiment the storage and retrieval system 100 may operate in a retail distribution center or warehouse to, for example, fulfill orders received from retail stores for case units (where case units as used herein means items not stored in trays, on totes or on pallets, e.g. uncontained). It is noted that the case units may include cases of items (e.g. case of soup cans, boxes of cereal, etc.) or individual items that are adapted to be taken off of or placed on a pallet. It is also noted that the term "freely arranged items" will be referred to herein as "items" for explanatory purposes. In accordance with the exemplary embodiments, shipping cases or case units (e.g. cartons, barrels, boxes, crates, jugs, or any other suitable device for holding items) may have variable sizes and may be used to hold items in shipping and may be configured so they are capable of being palletized for shipping. It is noted that when, for example, pallets of case units arrive at the storage and retrieval system the content of each pallet may be uniform (e.g. each pallet holds a predetermined number of the same item - one pallet holds soup and another pallet holds cereal) and as pallets leave the storage and retrieval system the pallets may contain any suitable number and combination of different case units (e.g. each pallet may hold different types of case units - a pallet holds a combination of soup and cereal). In alternate embodiments the storage and retrieval system described herein may be applied to any environment in which case units are stored and retrieved. The storage and retrieval system 100 may be configured for installation in, for example, existing warehouse structures or adapted to new warehouse structures. In one exemplary embodiment, the storage and retrieval system may include in-feed and out-feed transfer stations 170, 160, multilevel vertical conveyors 150A, 150B, a storage structure 130, and a number of autonomous vehicular transport robots 110 (referred to herein as "bots"). In alternate embodiments, the storage and retrieval system may also include robot or bot transfer stations 140 (<figref idref="f0008 f0009">Figs. 11A-11D</figref>), which may be located in transfer areas 295 of the storage and retrieval system. The in-feed transfer stations 170 and out-feed transfer stations 160 may operate together with their respective multilevel vertical conveyors 150A, 150B for transferring case units to and from one or more levels of the storage structure 130. It is noted that while the multilevel vertical conveyors are described herein as being dedicated inbound conveyors 150A and outbound conveyors 150B, in alternate embodiments each of the conveyors 150A, 150B may be used for both inbound and outbound transfer of case units/items from the storage and retrieval system. In one exemplary embodiment, the bots 110 may interface directly with the multilevel vertical conveyors 150A, 150B as will be described below while in alternate embodiments the bots 110 may interface indirectly with the multilevel vertical conveyors 150A, 150B through, for example, respective bot transfer stations 140 (which may have extendable fingers for interfacing with slatted support shelves of the multilevel vertical conveyors which may be substantially similar to those described herein with respect to the bots 110).

0019The storage structure 130 may include multiple levels of storage rack modules where each level includes an array of storage spaces (arrayed on the multiple levels and in multiple rows on each level), picking aisles 130A formed between the rows of storage spaces, and transfer decks 130B. In alternate embodiments each level of the storage rack modules may also include respective bot transfer stations 140. The picking aisles 130A and transfer decks 130B being arranged for transferring case units between any of the storage areas of the storage structure 130 and any shelf of any multilevel vertical conveyor 150A, 150B for placing case units into picking stock and to retrieve the ordered case units. The bots 110 may be configured to place items, such as the above-described retail merchandise, into picking stock in the one or more levels of the storage structure 130 and then selectively retrieve ordered items for shipping the ordered items to, for example, a store or other suitable location. As may be realized, the storage and retrieval system may be configured to allow random accessibility to the storage spaces as will be described in greater detail below. For example, all storage spaces in the storage structure 130 may be treated substantially equally when determining which storage spaces are to be used when picking and placing case units from/to the storage structure 130 such that any storage space of sufficient size can be used to store case units. The storage structure 130 of the exemplary embodiments may also be arranged such that there is no vertical or horizontal array partitioning of the storage structure. For example, each multilevel vertical conveyor 150A, 150B may be common to all or substantially all storage spaces (e.g. the array of storage spaces) in the storage structure 130 such that any bot 110 can access each storage space and any multilevel vertical conveyor 150A, 150B can receive case units from any storage space on any level so that the multiple levels in the array of storage spaces substantially act as a single level (e.g. no vertical partitioning). Conversely case units from any shelf of each multilevel vertical conveyor 150A, 150B can be transferred to any or each storage space throughout the storage structure or to each storage space of any level of the storage structure. The multilevel vertical conveyors 150A, 150B can also receive case units from any storage space on any level of the storage structure 130 (e.g. no horizontal partitioning).

0020The storage structure 130 may also include charging stations 130C for replenishing, for example, a battery pack of the bots 110. In one exemplary embodiment, the charging stations 130C may be located at, for example, a transfer area 295 (<figref idref="f0002">Fig. 2</figref>) so that the bot can substantially simultaneously transfer case units between, for example, the bot and a multilevel vertical conveyor 150A, 150B while simultaneously being charged.

0021The bots 110 and other suitable features of the storage and retrieval system 100 may be controlled by, for example, one or more central system control computers (e.g. control server) 120 through, for example, any suitable network 180. The network 180 may be a wired network, a wireless network or a combination of a wireless and wired network using any suitable type and/or number of communication protocols. It is noted that, in one exemplary embodiment, the system control server 120 may be configured to manage and coordinate the overall operation of the storage and retrieval system 100 and interface with, for example, a warehouse management system, which in turn manages the warehouse facility as a whole.

0022When an order for case units is made any bots 110 on the storage level of the requested case units retrieves the corresponding case units (e.g. pickfaces) from a designated storage area of the storage structure 130 (<figref idref="f0012">Fig. 14</figref>, Block 2300). The bot 110 traverses the picking aisle 130A in which the case units were stored and the transfer aisle 130B for accessing any desired shelf 730 (<figref idref="f0004">Fig. 7B</figref>) of any one of the multilevel vertical conveyors 150B (<figref idref="f0012">Fig. 14</figref>, Block 2310). It is noted that the case units that comprise the order may be picked by the bots in any order. For example, a first bot 110 may traverse, for example, the transfer deck 130B for any suitable amount of time to, for example, allow other bots to pick respective case units of the order and deliver those case units to the multilevel vertical conveyor 150B if the case units of the other bots are to be delivered to the multilevel vertical conveyor before the case units of the first bot 110. As described herein, the case units may be delivered to the multilevel vertical conveyor at a predetermined time according to, for example, a predetermined sequence in a first sortation of the case units (<figref idref="f0012">Fig. 14</figref>, Block 2320). The bot 110 transfers the case units to the desired shelf of the multilevel vertical conveyor as described above (<figref idref="f0012">Fig. 14</figref>, Block 2330). In alternate embodiments, the bots may provide the case units to bot transfer stations 140 located on a level of the storage structure 130 from which the ordered case units were picked. The multilevel vertical conveyor 150B transports the ordered case units to the out-feed transfer stations 160 at a predetermined time according to, for example, a predetermined sequence in a second sortation of the case units (<figref idref="f0012">Fig. 14</figref>, Block 2340). It is noted that the multilevel vertical conveyors 150B are configured to allow the case units to continuously revolve around the conveyor loop so that the case units can be moved to, for example, an out-feed transfer station at any suitable time for fulfilling an order. For example, a first case unit is placed on a first shelf of the multilevel vertical conveyor 150B and a second case unit is placed on a second shelf of the multilevel vertical conveyor 150B where the first shelf is located in front of the second shelf in a sequence of shelves of the multilevel vertical conveyor 150B and the second case unit is to be provided to the out-feed transfer station 160 before the first case unit. The first shelf (holding the first case unit) may be allowed to pass the out-feed transfer station without unloading the first case unit to allow the second case unit to be removed from the second shelf. Thus, the case units may be placed on the shelves of the multilevel vertical conveyor 150B in any order. The out-feed transfer station 160 removes the case units from a desired shelf of the multilevel vertical conveyor at a desired time (<figref idref="f0012">Fig. 14</figref>, Block 2350) so that the individual case units are transported to palletizing workstations 220 (<figref idref="f0002">Fig. 2</figref>) by conveyors 230 (<figref idref="f0002">Fig. 2</figref>) where the individual case units are placed on outbound pallets (or other suitable container-like transport supports) in, for example, a predetermined sequence (as described above) to form mixed pallets 9002 (<figref idref="f0011">Fig. 13</figref>) for shipping to a customer. The out-feed transfer stations 160 and the palletizing workstations 220 may be referred to collectively as an order assembly station. Other examples, of material handling systems in which case units are transferred to an outbound container can be found in United States Patent Application No. <patcit id="pcit0007" dnum="US10928289B"><text>10/928,289 filed on August 28, 2004</text></patcit>, and United States Patent Application No. <patcit id="pcit0008" dnum="US12002309B"><text>12/002,309 filed on December 14, 2007</text></patcit>, the disclosures of which are incorporated by reference herein in their entirety. As may be realized, the storage and retrieval system allows for ordering mixed case units of any suitable quantity without having to pick and transport, for example, entire trays, totes or pallets of case units to and from the storage structure 130.

0023Referring now to <figref idref="f0004">Fig. 7A</figref>, the multilevel vertical conveyors will be described in greater detail. It is noted that the input multilevel vertical conveyor 150A and associated in-feed transfer stations 170 (and in alternate embodiments, the bot transfer stations 140) will be described, however, the out-feed multilevel vertical conveyors 150B and out-feed transfer stations 160 may be substantially similar to that described below for their in-feed counterparts but for the direction of material flow out of the storage and retrieval system 100 rather than into the storage and retrieval system. As may be realized, the storage and retrieval system 100 may include multiple in-feed and out-feed multilevel vertical conveyors 150A, 150B that are accessible by, for example, bots 110 on each level of the storage and retrieval system 100 so that case units can be transferred from a multilevel vertical conveyor 150A, 150B to each storage space on a respective level and from each storage space to any one of the multilevel vertical conveyors 150A, 150B on a respective level. The bots 110 may be configured to transfer the case units between the storage spaces and the multilevel vertical conveyors with one pick (e.g. substantially directly between the storage spaces and the multilevel vertical conveyors). By way of further example, the designated bot 110 picks the uncontained case unit(s) from a shelf of a multilevel vertical conveyor, transports the uncontained case unit(s) to a predetermined storage area of the storage structure 130 and places the uncontained case unit(s) in the predetermined storage area (and vice versa).

0024Generally, the multilevel vertical conveyors include payload shelves 730 attached to chains or belts that form continuously moving or circulating vertical loops (the shape of the loop shown in the Figs. is merely exemplary and in alternate embodiments the loop may have any suitable shape including rectangular and serpentine) that move at a substantially constant rate, so that the shelves 730 use what may be referred to as the "paternoster" principle of continuous conveyance, with loading and unloading performed at any point in the loop without slowing or stopping (e.g. the payload shelves 730 continuously move at a substantially constant rate). The multilevel vertical conveyors may be controlled by a server, such as for example, control server 120, or any other suitable controller. One or more suitable computer workstations 700 may be connected to the multilevel vertical conveyors and the server 120 in any suitable manner (e.g. wired or wireless connection) for providing, as an example, inventory management, multilevel vertical conveyor functionality and control, and customer order fulfillment. As may be realized, the computer workstations 700 and/or server 120 may be programmed to control the in-feed and/or out-feed conveyor systems. In alternate embodiments the computer workstations 700 and/or server 120 may also be programmed to control transfer stations 140. In one exemplary embodiment, one or more of the workstations 700 and control server 120 may include a control cabinet, a programmable logic controller and variable frequency drives for driving the multilevel vertical conveyors 150A, 150B. In alternate embodiments the workstations 700 and/or control server 120 may have any suitable components and configuration. In one exemplary embodiment, the workstations 700 may be configured to substantially remedy any exceptions or faults in the in-feed and/or out-feed conveyors systems substantially without operator assistance and communicate fault recovery scenarios with the control server 120 and/or vice versa.

0025In this exemplary embodiment, the multilevel vertical conveyors 150A may include a frame 710 configured to support driven members such as, for example, chains 720. The chains 720 may be coupled to the shelves 730, which are movably mounted to the frame 710 such that the chains 720 effect substantially continuous movement of the shelves 730 around the frame 710 at a substantially constant rate. In alternate embodiments, any suitable drive link, such as for example, belts or cables may be used to drive the shelves 730. Referring also to <figref idref="f0007">Fig. 9</figref>, each shelf 730 may include, for example, supports 930 and a platform 900. The supports 930 may extend from the platform 900 and be configured for attaching and mounting the shelf 730 to, for example one or more drive chains 720. The platform 900 may include, for example, any suitably shaped frame 911, which in this example is generally "U" shaped (e.g. having lateral members connected by a span member at one end), and has any suitable number of spaced apart fingers 910 extending from the frame 911. The fingers 910 may be configured for supporting pickfaces 750, 752 (<figref idref="f0004">Fig. 7B</figref>) where each pickface comprises at least one uncontained case unit. In one exemplary embodiment, each of the fingers 910 may be removably fastened to a frame 911 for facilitating replacement or repair of individual fingers 910. The fingers 910, frame 911 (and supports 930) may form an integral structure or platform that defines the seating surface that contacts and supports the uncontained case units. It is noted that the shelf 730 illustrates only a representative structure and in alternate embodiments, the shelves 730 may have any suitable configuration and size for transporting pickfaces 750, 752. As will be described below, the spaced apart fingers 910 are configured to interface with, for example, a transfer arm or effector 1235 of the bots 110 and the in-feed transfer stations 170 for transferring the loads 750-753 between the multilevel vertical conveyor 150A and one or more of the transfer stations 170 or bots 110. In alternate embodiments, the spaced apart fingers 910 may be configured to interface with bot transfer stations 140 as described below.

0026The multilevel vertical conveyors 150A may also include a suitable stabilizing device(s), such as for example, driven stabilizing chains for stabilizing the shelves 730 during vertical travel. In one example, the stabilizing devices may include chain driven dogs that are engaged to the shelves in both the upward and downward directions to form, for example, a three point engagement with the shelf supports 930. The drive chains 720 for the shelves 730 and stabilizing devices may be drivingly coupled to for example, any suitable number of drive motors under the control of, for example, one or more of the computer workstations 700 and control server 120.

0027In one exemplary embodiment there may be any suitable number of shelves 730 mounted and attached to the drive chains 720. As can be seen in <figref idref="f0004">Fig. 7B</figref> each shelf 730 may be configured to carry, for exemplary purposes only, two or more separate pickfaces 750, 752 in corresponding positions A, C on the shelf 730 (e.g. a single vertical conveyor is functionally equivalent to multiple individually operated conveyors arranged adjacent one another). In alternate embodiments, as can be seen in <figref idref="f0007">Fig. 10</figref> the shelves 730' may be configured to carry, for exemplary purposes only, four separate pickfaces 750-753 in corresponding positions A-D. In still other alternate embodiments each shelf may be configured to carry more or less than four separate loads. As described above, each pickface may comprise one or more uncontained case units and correspond to the load of a single bot 110. As may be realized, the space envelope or area planform of each pickface may be different. By way of example, uncontained cases, such as those directly transported by the multilevel vertical conveyors have various different sizes (e.g. differing dimensions). Also, as noted each pickface may include one or more uncontained cases. Thus, the length and width of each pickface carried by the multilevel vertical conveyors may be different. In alternate embodiments each pickface may be broken between, for example, bots 110 where different portions of the pickface are transported by more than one bot 110 on, for example, different levels of the storage structure 130. As may be realized, when a pickface is broken each portion of the broken pickface may be considered as a new pickface by the storage and retrieval system 100. For exemplary purposes only, referring to <figref idref="f0006">Figs. 8A, 8B</figref> the shelves 730 of the multilevel vertical conveyors 150A, 150B may be spaced from each other by a predetermined pitch P to allow for placement or removal of loads 810, 820 from the substantially continuously moving shelves 730 as will be described below.

0028Referring now to <figref idref="f0007">Fig. 10</figref>, and as described above, the multilevel vertical conveyors, such as conveyor 150A are supplied with uncontained case units 1000 from in-feed transfer stations 170 (<figref idref="f0001">Fig. 1</figref>). As described above, the in-feed transfer stations 170 may include one or more of depalletizing workstations 210 (<figref idref="f0002">Fig. 2</figref>), conveyors 240 (<figref idref="f0002">Fig. 2</figref>), conveyor interfaces/bot load accumulators 1010A, 1010B and conveyor mechanisms 1030. As can be seen in <figref idref="f0007">Fig. 10</figref>, uncontained case units 1000 are moved from, for example depalletizing workstations 210 (<figref idref="f0002">Fig. 2</figref>) by conveyors 240. In this example, each of the positions A-D is supplied by a respective in-feed transfer station. As may be realized, while the transfer of case units is being described with respect to shelves 730' it should be understood that transfer of case units to shelves 730 occurs in substantially the same manner. For example, position A may be supplied by in-feed transfer station 170A and position C may be supplied by in-feed transfer station 170B. Referring also to <figref idref="f0004">Fig. 7A</figref> the in-feed transfer stations 170A, 170B, for supplying similar sides of the shelf 730 (in this example positions A and C form a first side 1050 of the shelf 730 and positions B and D form a second side 1051 of the shelf 730), may be located one above the other in horizontally staggered stacked arrangement (an exemplary stacked arrangement is shown in <figref idref="f0004">Fig. 7A</figref>). In alternate embodiments, the stacked arrangement may be configured so that in-feed transfer stations are disposed vertically in-line one above the other and extend into the multilevel vertical conveyors by different amounts for supplying, for example, positions A and B (and positions C and D) where positions A and B (and positions C and D) are disposed one in front of the other, rather than side by side. In alternate embodiments, the in-feed transfer stations may have any suitable configuration and positional arrangement. As can be seen in <figref idref="f0002">Figs. 2</figref> and <figref idref="f0007">10</figref>, the first side 1050 and second side 1051 of the shelf 730 are loaded (and unloaded) in opposing directions such that each multilevel vertical conveyor is located between respective transfer areas 295A, 295B (<figref idref="f0002">Figs. 2</figref> and <figref idref="f0007">10</figref>) where the first side 1050 interfaces with a transfer area 295B and the second side 1051 interfaces with transfer area 295A as will be described in greater detail below.

0029In this exemplary embodiment, the accumulators 1010A, 1010B are configured to form the uncontained case units 1000 into the individual pickfaces 750-753 prior to loading a respective position A-D on the multilevel vertical conveyor 730. In one exemplary embodiment, the computer workstation 700 and/or control server 120 may provide instructions or suitable control the accumulators 1010A, 1010B (and/or other components of the in-feed transfer stations 170) for accumulating a predetermined number of case units to form the pickfaces 750-753. The accumulators 1010A, 1010B may align the case units in any suitable manner (e.g. making one or more sides of the case units flush, etc.) and, for example, abut the case units together. The accumulators 1010A, 1010B may be configured to transfer the pickfaces 750-753 to respective conveyor mechanisms 1030 for transferring the pickfaces 750-753 to a respective shelf position A-D. In one exemplary embodiment the conveyor mechanisms 1030 may include belts or other suitable feed devices for moving the pickfaces 750-753 onto transfer platforms 1060. The transfer platforms 1060 may include spaced apart fingers for supporting the pickfaces 750-753 where the fingers 910 of the shelves 730 are configured to pass between the fingers of the transfer platforms 1060 for lifting (or placing) the loads 750-753 from the transfer platforms 1060. In another exemplary embodiment, the fingers of the transfer platforms 1060 may be movable and serve to insert the pickfaces 750-753 into the path of the shelves 730 in a manner similar to that described below with respect to the bot transfer stations 140. In alternate embodiments the in-feed transfer stations 170 (and out-feed transfer stations 160) may be configured in any suitable manner for transferring case units (e.g. the pickface formed by one or more case units) onto or from respective multilevel vertical conveyors 150A, 150B.

0030Referring now to <figref idref="f0008 f0009">Figs. 11A-11D</figref>, the multilevel vertical conveyors 150A transfer pickfaces 750-753 from, for example, the in-feed transfer stations 170 (or any other suitable device or loading system) directly to, for example, the bots 110. In alternate embodiments the multilevel vertical conveyors 150A transfer pickfaces 750-753 from, for example, the in-feed transfer stations 170 indirectly to the bots 110 through the bot transfer stations 140 associated with each of the levels in the storage structure 130. As may be realized, the bot transfer stations 140 are disposed on respective levels of the storage structure adjacent the path of travel of the shelves 730 of a respective multilevel vertical conveyor 150A. In one exemplary embodiment, there may be a bot transfer station 140 corresponding to each of the positions A-D on the shelves 730. For example, a first bot transfer station 140 may remove load 750 from position A on shelf 730 while another bot transfer station 140 may remove load 752 from position C on shelf 730 and so on. In other exemplary embodiments, one bot transfer station 140 may serve to remove or place case units in more than one position A-D on the shelves 730. For example, one bot transfer station 140 may be configured for removing loads 750, 752 from positions A, C on the first side of the shelf 730 while another bot transfer station 140 may be configured to remove loads 751, 753 from positions B, D on the second side 1051 of the shelf. In alternate embodiments the bot transfer stations 140 may have any suitable configuration for accessing any suitable number of positions A-D of the shelves 730.

0031In alternate embodiments, each bot transfer station 140 may include a frame 1100, one or more drive motors 1110 and a carriage system 1130. The frame 1100 may have any suitable configuration for coupling the bot transfer station 140 to, for example, any suitable supporting feature of the storage structure 130, such as one or more of the horizontal supports 610, 611 and vertical supports 612 (<figref idref="f0003">Fig. 5</figref>). The carriage system 1130 may be movably mounted to the frame 1100 through, for example, rails 1120 that are configured to allow the carriage system 1130 to move between retracted and extended positions as shown in <figref idref="f0008">Figs. 11A and 11B</figref>. The carriage system 1130 may include a carriage base 1132 and fingers 1135. The fingers 1135 may be mounted to the carriage base 1132 in a spaced apart arrangement so that the fingers 1135 extend from the carriage base 1132 in a cantilevered fashion. It is noted that each finger 1135 may be removably mounted to the carriage base 1132 for facilitating replacement or repair of individual fingers 1135. In alternate embodiments the fingers and carriage base may be of unitary one-piece construction. The fingers 1135 of the bot transfer stations 140 may be configured to pass between the fingers 910 of the shelves 730 of the multilevel vertical conveyors 150A for removing loads such as load 1150 (which may be substantially similar to loads 750-753) from the shelves 730. The bot transfer station 140 may also include a load 1150 positioning device 1140 that retractably extends between, for example, the spaced apart fingers 1135 for effecting positioning of the load 1150 in a predetermined orientation relative to the bot transfer station 140. In still other alternate embodiments the carriage system 1130 may have any suitable configuration and/or components. The one or more drive motors 1110 may be any suitable motors mounted to the frame 1100 for causing the extension/retraction of the carriage system 1130 and the extension/retraction of the positioning device 1140 in any suitable manner such as by, for exemplary purposes only, drive belts or chains. In alternate embodiments, the carriage system and positioning device may be extended and retracted in any suitable manner.

0032It is noted that while the interface between the bot transfer station 140 and the multilevel vertical conveyors is described it should be understood that interfacing between the bots 110 and the multilevel vertical conveyors may occur in substantially the same manner. For example, in operation, referring also to <figref idref="f0004 f0005">Fig. 7B-7D</figref> and <figref idref="f0006">8A-8B</figref>, inbound pickfaces (e.g. pickfaces, which include one or more case units, that are being transferred into the storage and retrieval system) such as pickface 1150 are loaded on and will circulate around the multilevel vertical conveyor 150A and be removed from a respective conveyor by, for example, one or more bots 110 for placement in a storage area of the storage structure (<figref idref="f0013">Fig. 15</figref>, Blocks 8000 and 8010). In the exemplary embodiments the input loading sequencing of case units onto the multilevel vertical conveyors 150A, 150B (e.g. such as at corresponding feeder input sides of transfer stations 170 and bot transfer locations on respective storage levels) may be substantially independent from the output or unloading sequence of the multilevel vertical conveyors 150A, 150B (e.g. such as at corresponding output sides of transfer stations 160 and bot transfer locations on respective storage levels) and vice versa. In one example, the pickface 1150 may be loaded onto the shelves 730 during an upward travel of the multilevel vertical conveyor 150A and off loaded from the shelves 730 during downward travel of the multilevel vertical conveyor 150A (See e.g. <figref idref="f0005">Figs. 7C and 7D</figref>). By way of example, multilevel vertical conveyor shelves 730i and 730ii (<figref idref="f0005">Fig. 7D</figref>) may be loaded sequentially, but when unloaded, shelf 730ii may be unloaded before shelf 730i. It is noted that the shelves 730 may be loaded through one or more cycles of the multilevel vertical conveyor. In alternate embodiments the pickface may be loaded or off loaded from the shelves 730 in any suitable manner. As may be realized, the position of the case units on the multilevel vertical conveyor shelf 730 defines the pickface position that the bot 110 picks from. The bot may be configured to pick any suitable load or pickface from the shelf 730 regardless of the pickface position on the shelf 730 or the size of the pickface. In one exemplary embodiment, the storage and retrieval system 100 may include a bot positioning system for positioning the bot adjacent the shelves 730 for picking a desired pickface from a predetermined one of the shelves 730 (e.g. the bot 110 is positioned so as to be aligned with the pickface). The bot positioning system may also be configured to correlate the extension of the bot transfer arm 1235 with the movement (e.g. speed and location) of the shelves 730 so that the transfer arm 1235 is extended and retracted to remove (or place) pickfaces from predetermined shelves 730 of the multilevel vertical conveyors 150A, 150B. For exemplary purposes only, the bot 110 may be instructed by, for example, the computer workstation 700 or control server 120 (<figref idref="f0004">Fig. 7A</figref>) to extend the transfer arm 1235 (see e.g. also <figref idref="f0010">Fig. 12</figref>) into the path of travel of the pickface 1150. As the pickface 1150 is carried by the multilevel vertical conveyor 150A in the direction of arrow 860 fingers 1235A (which may be substantially similar to fingers 1135 of the bot transfer station 140) of the bot transfer arm 1235 pass through the fingers 910 of the shelf 730 for transferring the pickface 1150 from the shelf 730 to the transfer arm 1235 (e.g. the pickface 1150 is lifted from the fingers 910 via relative movement of the shelf 730 and the transfer arm 1235). As may be realized, the pitch P between shelves may be any suitable distance for allowing the transfer of pickfaces between the multilevel vertical conveyor and the bot 110 while the shelves 730 are circulating around the multilevel vertical conveyor in a substantially continuous rate. The bot transfer arm 1235 may be retracted (in a manner substantially similar to that shown in <figref idref="f0009">Fig. 11C, 11D</figref>) so that the pickface 1150 is no longer located in the path of travel of the shelves 730 of the multilevel vertical conveyor 150A. It is noted that in alternate embodiments, where the bot transfer stations 140 are used, the positioning device 1140 may be extended through the fingers 1135 and the carriage system 1130 may be moved in the direction of arrow 1180 for abutting the pickface 1150 against the positioning device 1140 effecting positioning of the pickface 1150 in a predetermined orientation relative to, for example, the bot transfer station 140. The carriage system 1130 may be fully retracted as shown in <figref idref="f0009">Fig. 11D</figref> for transfer of the pickface 1150 to a bot 110 as will be described in greater detail below.

0033Referring to <figref idref="f0006">Fig. 8B</figref>, for transferring pickface in the outbound direction (e.g. moving pickface from or out of the storage and retrieval system) the bots 110 pick one or more a pickface, such as load 1150, from a respective predetermined storage area of the storage structure (<figref idref="f0013">Fig. 15</figref>, Block 8020). The pickfaces may be extended into the path of the shelves 730 of the multilevel vertical conveyor 150B (which is substantially similar to conveyor 150A) by the bot transfer arm 1235 through an extension of the transfer arm 1235 relative to a frame of the bot 110. It is noted that the pickfaces, such as pickface 1150, may be placed on the multilevel vertical conveyor 150 in a first predetermined order sequence (<figref idref="f0013">Fig. 15</figref>, Block 8030). The first predetermined order may be any suitable order. The substantially continuous rate of movement of the shelves 730 in the direction of arrow 870 cause the fingers 910 of the shelf 730 to pass through the fingers 1235A of the bot transfer arm 1235 such that the movement of the shelf 730 effects lifting the pickface 1150 from the fingers 1235A. The pickface 1150 travels around the multilevel vertical conveyor 150B to an out-feed transfer station 160 (which is substantially similar to in-feed transfer station 170) where is it removed from the shelf 730 by a conveyor mechanism 1030 in a manner substantially similar to that described above. The pickfaces may be removed from the multilevel vertical conveyor 150B by, for example the out-feed transfer stations 160 in a second predetermined order sequence that may be different and independent from the first predetermined order sequence (<figref idref="f0013">Fig. 15</figref>, Block 8040). The second predetermined order sequence may depend on any suitable factors such as, for example, the store plan rules 9000 (<figref idref="f0011">Fig. 13</figref>).

0034It is noted that the respective transfer of loads between the multilevel vertical conveyors 150A, 150B and the in-feed and out-feed transfer stations 170, 160 may occur in a manner substantially similar to that described above with respect to the bots 110 and bot transfer stations 140. In alternate embodiments transfer of pickfaces between the multilevel vertical conveyors 150A, 150B and the in-feed and out-feed transfer stations 170, 160 may occur in any suitable manner.

0035As can be seen in <figref idref="f0005">Figs. 7C and 7D</figref> the shelves 730 of the multilevel vertical conveyors 150A, 150B are loaded and unloaded by the in-feed and out-feed transfer stations 170, 160 and the bots 110 from a common side of the shelf 730. For example, the shelves are loaded and unloaded in the common direction 999 (e.g. from only one side of the shelf 730). In this example, to facilitate loading the multilevel vertical conveyor from only one side of the shelf, the multilevel vertical conveyors 150A, 150B circumscribe a respective one of the in-feed and out-feed transfer stations 170, 160 so that the pickfaces 1150 travel around the in-feed and out-feed transfer stations 170, 160. This allows the in-feed and out-feed transfer stations 170, 160 to be placed on the same side of the shelves 730 as the bots 110 for transferring pickfaces (and the case units therein) to and from the multilevel vertical conveyors 150A, 150B.

0036As described above, the components of the storage and retrieval system described herein are in communication with and/or controlled by control server 120. The control server 120 may include a collection of substantially concurrently running programs that are configured to manage the storage and retrieval system 100 including, for exemplary purposes only, controlling, scheduling and monitoring the activities of all active system components, managing inventory and pickfaces, and interfacing with the warehouse management system 2500. It is noted that a pickface as used herein may be one or more merchandise case units placed one behind the other in a storage space or area of a storage shelf to be used in pick transactions for filling customer orders. In one example, all case units forming a given pickface are of the same stock keeping unit (SKU) and originally from the same pallet. In alternate embodiments, each pickface may include any suitable case units. Each pickface may correspond to all or part of a bot load 750-753 (<figref idref="f0004">Fig. 7B</figref>). Conversely, the bot load may be established based on a pickface determination. As may be realized the determination of the pickfaces may be variable within the storage and retrieval system such that the size and locations of the pickface are dynamically changeable. It is also noted that interfacing with the warehouse management system allows the control server 120 to receive and execute pallet orders and to submit and execute replenishment orders as will be described below. The active system components may be the physical entities that act upon the case units to be stored and retrieved. The active system components may include, as a non-limiting example, items such as bots, in-feed and out-feed stations, multilevel vertical conveyors, the network and user interface terminals. In alternate embodiments, the active system components may also include bot transfer stations. The control server 120 may be configured to order the removal of case units from the storage and retrieval system for any suitable purpose, in addition to order fulfillment, such as, for example, when case units are damaged, recalled or an expiration date of the case units has expired. In one exemplary embodiment, the control server 120 may be configured to give preference to case units that are closer to their expiration date when fulfilling orders so those case units are removed from the storage and retrieval system before similar case units (e.g. with the same SKU) having later expiration dates. In the exemplary embodiments, the distribution (e.g. sortation) of case units in the storage and retrieval system is such that the case units can be provided for delivery to a palletizing station in any suitable order at any desired rate using only two sortation sequences. The control server 120 may be configured to fulfill orders so that the cases are provided by the bots 110 to respective multilevel vertical conveyors 150B in a first predetermined sequence (e.g. a first sortation of case units) and then removed from the respective multilevel vertical conveyors 150B in a second predetermined sequence (e.g. a second sortation of case units) so that the case units may be placed on pallets (or other suitable shipping containers/devices) in a predetermined order for building mixed pallets 9002 (<figref idref="f0011">Fig. 13</figref>). For example, in the first sortation of case units the bots 110 may pick respective case units (e.g. case unit) in any order. The bots 110 may traverse the picking aisles and transfer deck (e.g. circulate around the transfer deck) with the picked item until a predetermined time when the item is to be delivered to a predetermined multilevel vertical conveyor 150B. In the second sortation of case units, once the case units are on the multilevel vertical conveyor 150B the case units may circulate around the conveyor until a predetermined time when the item are to be delivered to the out-feed transfer station 160. Referring to <figref idref="f0011">Fig. 13</figref>, it is noted that the order of case units delivered to the pallets may correspond to, for example, store plan rules 9000. The store plan rules 9000 may incorporate, for example, an aisle layout in the customer's store or a family group of case units corresponding to, for example, a particular location in the store where the pallet will be unloaded or a type of goods. The order of case units delivered to the pallets may also correspond to characteristics 9001 of the case units such as, for example, compatibility with other case units, dimensions, weight and durability of the case units. For example, crushable case units may be delivered to the pallet after heavier more durable case units are delivered to the pallet. The first and second sortations of the case units allow for the building of mixed pallets 9002 as described herein.

0037The control server 120 in combination with the structural/mechanical architecture of the storage and retrieval system enables maximum load balancing. As described above, the storage spaces/storage locations are decoupled from the transport of the case units through the storage and retrieval system. For example, the storage volume (e.g. the distribution of case units in storage) is independent of and does not affect throughput of the case units through the storage and retrieval system. The storage array space may be substantially uniformly distributed with respect to output. The horizontal sortation (at each level) and high speed bots 110 and the vertical sortation by the multilevel vertical conveyors 150B substantially creates a storage array space that is substantially uniformly distributed relative to an output location from the storage array (e.g. an out-feed transfer station 160 of a multilevel vertical conveyor 150B). The substantial uniformly distributed storage space array also allows case units to be output at a desired substantially constant rate from each out-feed transfer station 160 such that the case units are provided in any desired order. To effect the maximum load balancing, the control architecture of the control server 120 may be such that the control server 120 does not relate the storage spaces within the storage structure 130 (e.g. the storage array) to the multilevel vertical conveyors 150B based on a geographical location of the storage spaces (which would result in a virtual partitioning of the storage spaces) relative to the multilevel vertical conveyors 150B (e.g. the closest storage spaces to the multilevel vertical conveyor are not allocated to cases moving from/to that multilevel vertical conveyor). Rather, the control server 120 may map the storage spaces uniformly to each multilevel vertical conveyor 150B and then select bots 110, storage locations and output multilevel vertical conveyor 150B shelf placement so that case units from any location in the storage structure come out from any desired multilevel vertical conveyor output (e.g. at the out-feed transfer stations) at a predetermined substantially constant rate in a desired order for building the mixed pallets 9002 (<figref idref="f0011">Fig. 13</figref>).

0038In accordance with a first exemplary embodiment, a transport system for a storage and retrieval system having an array of storage levels is provided. Each storage level having respective storage areas. The transport system including, a vertical conveyor having a frame and support shelves movably coupled to the frame, each support shelf being configured to hold one or more uncontained case units in predetermined areas of the support shelf, and transfer vehicles disposed on respective ones of the storage levels, the vertical conveyor having a conveyor to transfer vehicle interface configured to transfer the uncontained case units substantially directly between each support shelf and the transfer vehicles for transport to the storage areas in substantially one transfer vehicle picking operation.

0039In accordance with the first exemplary embodiment, the predetermined areas comprise an array of areas.

0040In accordance with the first exemplary embodiment, the support shelves include first elongated fingers and the transfer vehicles include second elongated fingers, the first and second elongated fingers being configured to pass between one another for transferring uncontained case units between each support shelf and the transfer vehicles.

0041In accordance with the first exemplary embodiment, each support shelf of the vertical conveyor is common to each storage area on each storage level.

0042In accordance with the first exemplary embodiment, each support shelf of the vertical conveyor is common to each storage space in the array of storage levels.

0043In accordance with the first exemplary embodiment, each storage area has fixed structure that defines a seating surface contacting an uncontained case unit stored in the storage area.

0044In accordance with a second exemplary embodiment, a vertical conveyor system for transporting uncontained case units to and from a multilevel storage structure having an array of vertically stacked storage levels is provided. The vertical conveyor system including, a multilevel vertical conveyor including a frame, a drive member connected to the frame, and support shelves coupled to the drive member where the drive member is configured to move the support shelves relative to the frame in a substantially continuous vertical loop, each of the support shelves being configured to support multiple uncontained case units where each of the multiple uncontained case units is disposed at a respective predetermined area of a respective support shelf. The vertical conveyor system further including at least one transfer station extending into a path of the support shelves, the at least one transfer station being configured to load and unload the uncontained case units from a respective predetermined area of a support shelf, wherein at least one of the uncontained case units are placed in or removed from the predetermined areas of the respective support shelf substantially independent of other uncontained case units disposed in other different ones of the predetermined areas of the respective support shelf.

0045In accordance with the second exemplary embodiment, the at least one transfer station comprises at least one in-feed transfer station extending into a path of the support shelves, the support shelves being configured to interface with the at least one in-feed transfer station to receive the uncontained case units, from the at least one in-feed transfer station, in at least one predetermined area of an inbound support shelf, the predetermined area of the inbound support shelf corresponding to a location of the at least one in-feed transfer station.

0046In accordance with the second exemplary embodiment, the at least one transfer station comprises at least one out-feed transfer station extending into the path of the support shelves, the support shelves being configured to interface with the at least one out-feed transfer station to remove the uncontained case units, with the at least one out-feed transfer station, from at least one predetermined area of an outbound support shelf, the predetermined area of the outbound support shelf corresponding to a location of the at least one out-feed transfer station.

0047In accordance with the second exemplary embodiment, the predetermined areas of the respective support shelf comprise an array of predetermined areas.

0048In accordance with the second exemplary embodiment, each support shelf comprises first elongated fingers and each of the in-feed and out-feed transfer stations comprises second elongated fingers, the first and second elongated fingers being configured to allow the support shelves to pass through the in-feed and out-feed transfer stations for effecting a transfer of the multiple uncontained case units.

0049In accordance with the second exemplary embodiment, one or more of the in-feed transfer stations and out-feed transfer stations are disposed in a horizontally staggered vertical stack on respective inbound and outbound sides of the vertical conveyor system.

0050In accordance with the second exemplary embodiment, one or more of the in-feed transfer stations and out-feed transfer stations are disposed in vertical stacks one above the other on respective inbound and outbound sides of the vertical conveyor system such that the vertically stacked in-feed and out-feed transfer stations extend into respective inbound and outbound shelves by different amounts than other ones of the in-feed and out-feed transfer stations.

0051In accordance with a first example of the second exemplary embodiment, The vertical conveyor system of claim 7, further comprising bot transfer locations disposed on each level of the multilevel storage structure for allowing transport vehicles to transfer the uncontained case units between storage modules disposed on each level and the support shelves.

0052In accordance with the first example of the second exemplary embodiment, the transport vehicles are configured to interface directly with the support shelves, the transport vehicles being configured to transport the at least one uncontained case unit between the support shelves and the storage modules with substantially one picking operation.

0053In accordance with the second exemplary embodiment, the at least one in-feed transfer station comprises an accumulator configured to form individual bot loads of uncontained case units for placement into the respective predetermined area of the inbound support shelf, where the individual bot loads include at least one uncontained case unit.

0054In accordance with the second exemplary embodiment, the at least one in-feed transfer station comprises a depalletizer for removing the uncontained case units from a container and the at least one out-feed transfer station comprises a palletizer for placing the uncontained case units to a container.

0055In accordance with the second exemplary embodiment, the multilevel vertical conveyor and the at least one out-feed transfer station are configured such that uncontained case units are removed from the multilevel vertical conveyor in a predetermined order.

0056In accordance with a third exemplary embodiment, a method for transferring uncontained case units to and from a multilevel storage structure having an array of vertically stacked storage levels is provided. The method includes providing a substantially continuously moving vertical loop of support shelves, each of the support shelves being configured to support multiple uncontained case units in an array of predetermined areas, and transferring the uncontained case units to a respective predetermined area of an inbound support shelf of the continuously moving vertical loop of support shelves with at least one in-feed transfer station extending into a path of the support shelves, the respective predetermined area of the inbound support shelf corresponding to a location of the at least one in-feed transfer station, wherein uncontained case units are individually placed in or removed from each of the predetermined areas of a respective support shelf substantially independent of other uncontained case units disposed in other different ones of the predetermined areas of the respective support shelf.

0057In accordance with a first example of the third exemplary embodiment, the method further includes transferring the uncontained case units from the support shelves of the continuously moving vertical loop of support shelves with at least one out-feed transfer station extending into the path of the support shelves, the at least one out-feed transfer station being configured to remove the uncontained case units from a respective predetermined area of an outbound support shelf, the respective predetermined area of the outbound support shelf corresponding to a location of the at least one out-feed transfer station.

0058In accordance with a first example of the third exemplary embodiment, transferring uncontained case units between the at least one in-feed transfer station and at least one out-feed transfer station and the support shelves is effected by passing first elongated fingers of the support shelves through second elongated fingers of a respective one of the in-feed and out-feed transfer stations.

0059In accordance with a fourth exemplary embodiment, an automated case unit storage system for handling case units that are adapted for being palletized for shipping to and from a warehouse is provided. The automated case unit storage system includes a multilevel array of storage spaces arrayed on multiple static levels and in multiple rows at each level, each storage space of the array being capable of holding an uncontained case unit therein, a continuous vertical lift having a lift support configured for holding and lifting the uncontained case unit to the levels of the array, the continuous vertical lift moving the lift support substantially continuously at a substantially constant rate, an input for inputting the uncontained case units onto the lift support of the continuous vertical lift, and an output for outputting the uncontained case units from the lift support of the continuous vertical lift, wherein the continuous vertical lift is configured so that outputted uncontained case units from the continuous vertical lift are disposed in a predetermined order that is independent from an order sequence in which the uncontained cases are input to the continuous vertical lift.

0060In accordance with the fourth exemplary embodiment, the continuous vertical lift is a common lift to each storage space on the at least one level.

0061In accordance with the fourth exemplary embodiment, the continuous vertical lift is a common lift to each storage space of the array of storage spaces.

0062In accordance with the fourth exemplary embodiment, each storage space has fixed structure that defines a seating surface contacting the uncontained case unit stored in the storage space.

0063It should be understood that the exemplary embodiments described herein may be used individually or in any suitable combination thereof. It should also be understood that the foregoing description is only illustrative of the embodiments. Various alternatives and modifications can be devised by those skilled in the art without departing from the embodiments. Accordingly, the present embodiments are intended to embrace all such alternatives, modifications and variances that fall within the scope of the appended claims.