AUTOMATED WORK CENTER

Abstract: An automated work center for use in materials handling operations is disclosed . The work center includes a randomly accessible vertically moving temporary storage queue (11) for receiving containers (25) that hold material goods. A fixed loading ramp (20) is arranged to receive containers (20) from an external system and to load the received containers onto the storage queue (11). A work area (5) having a plurality of rotatable work tables (7) provides and gives the operator access to the containers. A delivery system (14) transfers containers between the storage queue (11) and the work tables (7) and a takeaway system (16) transfers containers between the work area and the conveyor network. An automated control system (17) coordinates the delivery of containers between the temporary storage queue (11) and the work area (5). A consolidation queue (18) having a multiplicity of vertically spaced shelves may be disposed opposite the work tables (7) to facilitate the consolidation of ordered goods.

Description: AUTOMATED WORK CENTER This application is a Continuation-in-Part of co- pending Applications Serial Nos. 815,808 filed January 2, 1986, 015,083 filed February 17, 1987 and 158,310 filed February 22, 1988. Reference is also made to co-pending Applications Serial Nos. 031,989 filed March 30, 1987 which is a continuation-in-part of application Serial No. 800,337 filed November 21, 1985, and 192,419 filed April 29, 1988. Each of these co-pending applications is incorporated herein by reference. Background of the Invention The present invention relates to an automated in¬ tegrated work station for handling goods within distribution and production environments. In one of the preferred embodiments the work station is specifically adapted for consolidating goods. Many modern distribution systems require the storage and retrieval of thousands of inventoried goods. Often goods must be stored in bins or containers due to their size or delicate construction. Therefore, storage requires loading the containers and delivering the containers to a known location where they can later be retrieved as neces¬ sary. When an order is received, the desired items must be , picked from their respective storage position and prepared for either shipping or use. An effective warehousing operation requires the ability to both rapidly retrieve a wide variety of goods from storage and to efficiently dispose of the retrieved items. The present invention relates generally to an automated work station for rapidly and effectively disposing of retrieved items. The w rk 5 station disclosed may also be used to receive goods into the storage system. An example of an existing complex distribution and storage application is the environment of an electronic product manufacturing and/or repair facility wherein the 0 products built incorporate printed circuit boards. Such warehousing applications may require storage of as many as 150,000 components, the vast majority of which would fit into 6"x6"x.l8 " compartments. In any given day as many as 5 to 10 thousand assorted components may be drawn from the 5 storage facility. In the environment of a repair facility, there must also be an effective mechanism for storing various items. The stored items may include working parts associated with a malfunctioning part in the process of being repaired and/or components that cannot be repaired Q using parts in stock while the unavailable parts are on order. Absent effected integration between the storage system and the work stations of the repair or manufacturing facilities, the combined man hours lost between delivering the goods to. the appropriate work station and the down time 5 at various work stations as they wait for supplies to be delivered would make the facility cost prohibitive. Another typical example of a complex distribution operation is a consumer products and pharmaceutical ware¬ housing facility which stores and arranges such products for 0 delivery to retail outlets. Modern consumer products warehousing facilities may require the storage of on the order of 25,000 stock items which must be stored in both case lots and piece lots. The individual stock items may * range in size anywhere between l ,, xl"xl" to 36"x36"xl8". A 5 representative warehouse may have on the order of 1000 customers with in the range of 400 to 800 customers placing orders on any given day. The orders may call for. as many as 60,000 individual stock units and the actual number of items requested for each particular stock unit may widely vary. Additionally, it is desirable to package the ordered goods for each customer in lots of related goods rather than sending each customer a truckload randomly containing all of the goods that particular customer requested. For example, in the consumer products and pharmaceutical application described, related families of products might include RX, hair care products, cosmetics, etc.. Consolidating the orders in groups of related goods facilitates rapid re¬ stocking at the retail store when the goods are ultimately delivered. Often, the ordered goods are delivered in totes designed specifically for the purpose of transportation between the warehouse and the retail stores. Yet another application wherein efficiently integrated work centers are required is in the environment of a production facility. Recent studies investigating product¬ ivity and quality control have suggested that it is often more efficient to allow an individual worker to assemble whole products (or at least substantial components) , rather than using an extended production line wherein each employee adds only one or two small parts to a larger system. A drawback to such systems is that in order to effectively allow a single assembler to put together a product having a large number of parts, it is important to "kit" the parts. That is, they need to be arranged in readily accessible groups, preferably in the reverse order of construction. In many production lines, the kiting stage proves to be the slowest link. Therefore, there is a need for a work center that has access to all the parts and is capable of effec¬ tively kiting parts for production requirements. To facilitate these and other distribution applica¬ tions, numerous integrated warehousing systems have hereto¬ fore been proposed. Such systems traditionally include a work station of some sort. For example, Japanese Patent Application No. 53-37829 discloses a method for assorting goods that are stored on fixed storage shelves. The system contemplates moving boxes containing ordered goods from a storage shelf onto a horizontal loop-type conveyor which transfers the boxes to a branch line wherein they are reviewed by an operator. The operator looks at the goods in the box and then identifies the customers who needs such goods. He then drives a second loop-type conveyor to bring a container before him into which the ordered goods may be placed. However, such a system has significant time delays in. delivering goods to the operator. Further, the system is not fully automated and the equipment provided is not organized to maximize efficiency. Additionally, the conveyors disclosed are horizontally oriented which requires devoting abundant floor space to the material handling operation. When the demands on the system change (tradi- tionally volume tends to rise dramatically) , the expansive floor space required severely limits the ability to expand the system to meet the increased demand without adding to the size of the warehouse. It will be appreciated that the increasing cost of space and the costs associated with materials moving about an expansive area have become significant drawbacks to such ' approaches. Thus, although the systems heretofore available have greatly increased the speed and effectiveness of material handling, they still lack the ability to coordinate order consolidating activi- ties fast enough to meet current demand in numerous applica¬ tions. Summary of the Invention Accordingly, it is a primary objective of the present invention to provide a new and improved work station for use in conjunction with warehousing, production and repair facilities for handling the disposition of items in great quantity and variety wherein required manual operations are minimized. Another object of the invention is to provide a work station having temporary storage facilities for queuing inventoried items for random delivery to a work area. Another object of the invention is to provide an efficient work station for consolidating a wide range of variable orders using a minimal amount of manual labor. Another object of the invention is to provide an efficient work station for receiving goods into a storage system using a minimal amount of manual labor. To achieve the foregoing and other objects and in accordance with the purpose of the present invention, an automated work station is provided for use in materials handling operations. The work station includes a randomly accessible temporary storage queue for receiving containers that hold material goods. Loading means are provided for receiving containers from an external conveyor network and loading the received containers into the storage queue. A work area is provided to give operators access to the containers. A delivery system transfers containers between the temporary storage queue and the work area while a takeaway system transfers containers between the work area and the conveyor network. An automated control system coordinates the delivery of container between the temporary storage queue and the work area. The temporary storage queue preferably takes the form of a vertically moving storage queue having a multiplicity of vertically space shelves arranged about an endless loop, wherein each of the shelves is adapted to receive at least one container. A fixed loading ramp is provided to load containers onto the vertical queue. To facilitate loading the vertical queue, the shelves are rotated about the endless loop until an empty shelf is disposed adjacent the loading ramp wherein loading may take place. To unload the vertical queue, the shelf carrying the container to be unloaded is rotated until it is disposed adjacent the delivery means at which time the container may be discharged onto the delivery system for transportation to the work area. In a preferred embodiment, the work area takes the form of a plurality of rotatable work tables. In another preferred embodiment, the work center is designed to facilitate consolidating an extremely large number of customer orders. In this embodiment a rotational consolidation queue is provided that carries a large number of totes suitable for receiving individual consolidated orders. The consolidation queue is disposed in close proximity to the work area so that an operator may readily transfer goods -between the work area and the consolidation queue. The consolidation queue preferably includes a multiplicity of vertically spaced shelf pans carried about a track that forms an endless loop. Each shelf pan includes a multiplicity of tote pads each adapted to hold one of the totes. An opening mechanism, that may take the form of a plurality of pneumatic rams, is provided to push particular totes onto a fixed loading shelf to provide an operator with access to the totes. A preferred control system for the work station includes a queue controller for directing movements of the temporary storage queue and a conveyor controller for managing the activities of the delivery and takeaway systems. In embodiments having a plurality of work tables and a consolidation queue, individual component controllers in the form of a work table controller that manages the activities of the work tables and a consolidation controller that orchestrates movements of the consolidation queue would be provided as well. A dedicated work center controller integrates and manages the activities of the various component controllers. Each of the component controllers communicates with the work center controller and the other component controllers over a primary local area network. In a preferred architecture, a multiplicity of logic boards are provided for directly controlling the mechanical movements of the various components. Each of the component controllers has a plurality of associated logic boards for directly controlling the mechanical movements of the particular component controlled by the associated component controller. Each component controller has an associated secondary local area network over which the component controller communicates with its associated component controllers. Preferably, each component controller further has an associated interface board having a plurality of buffers for receiving communications from the logic board and temporarily storing the information transmitted by the logic boards until the component controller requests the transmitted information. In a preferred method of operation aspect of the invention, the work station is used to consolidate customer orders, production kits, or the like. In such a system, a multiplicity of orders for material goods are received. The control system automatically assigns particular totes to receive specific ordered goods. Containers holding ordered goods are then delivered to the work area. Goods disposed within a container in the work area are selected for distribution and the operator is informed of both the selected goods and the location of an active container that holds the selected goods. The consolidation queue is rotated until a shelf holding at least one tote designated to receive the selected goods is disposed adjacent the fixed loading shelf. A tote designated to receive the selected goods is then automatically opened and the operator is informed of the quantity of the selected goods that are to be placed into the open tote. The ordered number of the selected goods are placed into the open tote which is then closed. The tote opening and queue rotating steps are repeated as necessary to distribute the selected goods. The goods selecting, queue rotating and tote opening steps are repeated as necessary to consolidate all of the ordered items into the totes. Each time the all of the materials selected for distribution within a particular container have been distributed, the spent container is discharged from the work area and, when appropriate, an additional container that carries material goods to be distributed is automatically delivered to the work area. In an additional preferred embodiment, a multiplicity of containers are originally requested from an external storage system for delivery to the work station. The received containers are loaded onto the vertical queue for temporary storage. When containers are discharged from a particular work table within the work area, a container request is made for the delivery of an additional designated container to the work table that discharged a container. Similarly, each time a container is transferred from the temporary storage queue, a request is made for the delivery of an additional container to the work station from the external storage system. In an alternative method of operation the work station is utilized as a receiving station for accepting inventory items into a storage system. Brief Description of the Drawings The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which: FIGURE 1 is a diagrammatic floor plan of a work station having a pair of work areas supported by a single vertical queue in accordance with the present invention. FIGURE 2 is a diagrammatic floor plan of a simplified warehousing system incorporating a work station in accor¬ dance with the present invention. FIGURE 3 is a diagrammatic side view of a typical rotating work table as shown in Figure 1. FIGURE 4 is a perspective view of a typical consolida¬ tion queue as shown in Figure 1 with the front panel removed. FIGURE 5 is a side view of a typical vertical queue as shown in Figure 1 including the supporting frame and highlighting the shelf guiding arrangement. FIGURE 6 is a diagrammatic side view of the vertical queue shown in Figure 5 with the frame and guiding channels remove . FIGURE 7 is a top view of a vertical queue shown in Figure 5 with the frame removed. FIGURE 8 is a top view of a vertical queue shelf taken along line 8-8 in Figure 5 and including a soft stop mechanism. FIGURE 9 is a side view of the soft stop mechanism shown in Figure 8. FIGURE 10a is a side elevational view of a drive assembly suitable for powering the vertical queue. FIGURE 10b is a cross sectional view of the drive assembly shown in Figure 10a taken along the line lOb-lOb. FIGURE 11a is a front elevational view -of a weldment attachment for the drive assembly shown in Figure 10. FIGURE lib is a side elevational view of the weldment attachment shown in Figure 11a. FIGURE 12a is a side view of a portion of the drive chain for the drive assembly as shown in Figure 10. FIGURE 12b is a top view of the drive chain shown in Figure 12a. FIGURE 13 is a side elevational view of the guide track for the endless loop that comprises the vertical queue. FIGURE 14 is a cross sectional view of the guide track shown in Figure 13. FIGURE 15 is an edge view of a portion of the guide track shown in Figure 13 " with the continuous loop in place. FIGURE 16 is a cutaway front view of the guide roller assembly for the compression chain. FIGURE 17a is a front elevational view of a inner link for the compression chain. FIGURE 17b is a side elevational view of the inner compression chain link shown in Figure 17a coupled to its adjacent outer links. FIGURE 18 is a time lapse diagrammatic view illustrat¬ ing the travel of the weldment about the drive gear under the influence of the guide channel. FIGURE 19 is a time lapse diagrammatic view illustrat¬ ing the travel of the weldment about the idler gear. FIGURE 20 is a back elevational view of the guide channel. FIGURE 21 is a side elevational view of a flow through power operated stopper assembly. FIGURE 22 is a side view of the blocker assembly. FIGURE 23 is a top view of the rotating work table shown in Figure 3. FIGURE 24 is a front view of one of the drive assembly that raises and lowers the rotating work table platform. FIGURE 25 is a side view of the coupling between the front edge of the work table base and its drive chain with the sleeve and post partially cut away. FIGURE 26 is a side view of the coupling between the back edge of the work table base and its drive chain. FIGURE 27 is a top view of the rotating work table base. FIGURE 28 is a top view of platform portion of the rotating work table with the rollers removed. FIGURE 29 is a top view of the geneva drive that rotates the work table platform relative to its base. FIGURE 30 is a side view of the geneva drive system shown in Figure 29. FIGURE 31 is a side view of the gate assembly for retaining containers on the work table platform. FIGURE 32 is a top view of the bottom shelf portion of a consolidation queue pan. FIGURE 33 is a cut away top view of the consolidation queue taken at the level of the fixed loading shelf. FIGURE 34 is a top view of a consolidation queue as shown in Figure 33 with totes in place and highlighting the extension of the multistage pneumatic rams. FIGURE 35 is a side view of the self pan shown in Figure 32. FIGURE 36 is a front view of the consolidation queue incorporating a conveyor stub for supplying empty totes. FIGURE 37 is a plan view of an automatic tote loading mechanism. FIGURE 38 is a top plan view of a shipping and consoli¬ dation queue arrangement. FIGURE 39 is a perspective view of a suitable con- tainer. FIGURE 40 is a plan view of a receiving work station. FIGURE 41 is a block diagram for representative work center control system. FIGURE 42 is a more detailed block diagram of a particular work center controller as seen in Figure 40. Detailed Description of a Preferred Embodiment The automated work center of the present invention com¬ prises a plurality of integrated components adapted to facilitate high speed handling and distribution of bulk storage goods. Referring initially to Figure 1, an embodi¬ ment of the work center chosen for the purpose of illustra¬ tion includes two work areas 5 each having a plurality of work tables 7, a temporary storage queue 9 that may take the form of vertical queue 11, a supply conveyor 12, a delivery system 14, a takeaway system 16, a control system 17 that manages the activities of the work center and a consolida¬ tion queue 18. The work center is adapted to be integrated into a wide variety of distribution, warehousing and production environ- ments. In a simplified embodiment, the work center is designed to substantially continuously provide an operator with needed materials. In more sophisticated embodiments, the work center may be integrated to assist an operator consolidate customer orders or production kits or to receive inventory into the facility. Alternatively the work center may be configured to facilitate inspection, rewarehousing, replenishment, inventory monitoring and/or production assembly operations. To facilitate explanation, the system will be described in the environment of a consumer products distribution system as discussed above. Referring next tc Figure 2, in such a system, the inventoried items are kept in containers stored in a remote storage structure 2. When a customer order is received that requests a particular material good, the container holding the requested goods is selectively picked from the storage structure by an extrac¬ tion assembly and delivered to the work center via a suitable conveyor network 24. By way of example, suitable storage structures are disclosed in co-pending Application Serial No. 192,419, filed April 29, 1988, as well as in U.S. Patent Nos. 4,422,554 and 4,561,820, each of which is incorporated herein by reference. More conventional storage and retrieval systems that utilize multi-level fixed storage shelves in combination with an extractor picking mechanism may be used as well. The bulk goods may be delivered to the work station in any suitable form. For the purposes of illustration, the system will be described as though the stored items are kept in containers 25 as described below. It should, however, be understood that they may be delivered on pallets, in boxes or in their original packaging without departing the spirit of the invention. The containers 25 are preferably open boxes that are sized appropriately to receive the stored goods. A repre- sentative container 25 is shown in Figure 39. The con¬ tainers are preferably square so that they may be delivered to the operator in any orientation. The containers must be large enough to hold reasonable quantities of the inven¬ toried goods, yet they must be small enough so that an operator can readily pick the goods therefrom. By way of example, 36x36x24" containers are suitable for most consumer product applications. In applications where extremely small parts or small numbers of each item are inventoried, smaller containers on the order of 24x24x16" would be appropriate. The containers 25 may be formed from a molded fiber¬ glass reinforced resin material. Each container has an identification indicia 36 that individually identifies the particular container. By way of example, the containers may be numbered sequentially with the numbers being applied in bar coded form to each exterior corner of the container. Bar code labels may be readily printed at the edge of the container corners. It is desirable to label each corner to enable a single scanner to identify the container regardless of its orientation as it passes the scanner. With larger containers it may also be desirable to control the orienta¬ tion of the container when it is presented to an operator. With such systems, the bar code labels are .coded to indi¬ vidually identify each particular corner. In most warehousing operations, the sizes of the stored goods will vary widely. Thus, for compatibility relatively large containers are used so that only one or two container sizes need be handled by the distribution system. " To minimize the empty shelf space, many of the containers would be subdivided into multiple compartments 27 by placing wall inserts 28 into the containers. Generally, there would be containers having a wide range of compartment sizes within the distribution or production system, with the actual number of containers having a given compartment size and being entirely dependent upon the nature of the goods being stored. To maximize flexibility, wall inserts 28 may be removable so that the number of compartments within any container may be readily altered. To facilitate automatic control, each compartment 27 has a specific designation within the container 25. It is contemplated that each container will have only compartments 27 of a uniform size although it should be appreciated that this is not a requirement. . Referring to Figure 1, a typical work center 1 includes one or more work areas 5 having a plurality of work tables 7 adapted to receive the containers 25. A randomly accessible temporary storage queue 9 preferably in the form of vertical queue 11 serves as a holding point where the containers may be temporarily stored before delivery to the work tables. Thus, containers need not be supplied to the work tables 7 in the same order that they are received by the work center. The temporary storage serves the important function of acting as a buffer for holding the next few containers that will be required by the operator. Thus, when an operator is prepared to receive the next working container, it may readily be delivered to the work tables without experiencing the delays likely to occur if the container was requested from the storage structure. The actual construction of the vertical queue 11 may vary widely within the scope of the invention. In operation, containers are carried to the work center by an external conveyor network 24 that delivers containers to supply conveyor 12. As containers enter the work center they pass over supply conveyor 12 to any one of a plurality of loading ramps 20 that feed vertical queue 11. When a container is properly positioned on a loading ramp, the vertical queue 11 is rotated until an empty shelf appears adjacent the loading ramp. The container may then be loaded onto the empty shelf. The vertical queue is randomly accessible, therefore, when a particular container is requested for delivery to the work area, the vertical carousel is rotated until the requested container is adjacent a discharge station 40 wherein it may be unloaded from the vertical queue onto delivery system 14 for trans- portation to one of the work tables. The work tables present the containers to an operator in a position such that the operator may readily access the contents of the container. After the operator is finished working with the contents of the container, the container is discharged from the work table to takeaway system 16 which returns the container to the conveyor network for delivery either to another work center or to the storage structure. In embodiments wherein the containers are expected to be relatively large, the work tables are preferably rotatable so that the container may be presented to the operator in any orientation. Specifically, the container is always positioned such that the portion of the container that _ _ requires service will face the operator. This makes it easier to access goods within the container. The work center may be arranged to function as an issue station that facilitates consolidation of customer orders, production kits, and the like. Although the actual con¬ struction of the issue station may vary a great deal within the scope of the invention, as seen in Figure 1, each work area within the described embodiment of the issue work station contains a consolidations queue 18 adapted to hold a large number of tote drawers 19. The consolidation queue forms a vertically traveling carousel having a multiplicity of shelves. Each shelf has a plurality of tote pads each adapted to receive at least one tote 19. Using the consumer products application previously described, the totes would be designated to receive particular customer orders. Throughout the rest of this disclosure, the system will be described as though a single vertical queue 11 services a single work area. However, it should be appreciated that a single vertical queue could readily service two or more work areas as shown in Figure 1. When an order is received for goods " found within the warehousing system, the operator or an automatic controller would request containers holding the desired goods from the storage structure 2 as previously described. It will be appreciated that a particular customer order may request several different stock items. Thus, when the operator re¬ ceives a container holding some of the ordered goods, he would place those goods in a tote 19 associated with the particular order. As the remaining goods are received, they would be placed in the same tote drawer 19 until the order is filled. Once the order has been filled, a shipping invoice or production document is printed and placed into the tote and the tote is dispatched to a shipping queue, a packing station, an assembly station, a storage structure, or the like, depending upon the requirements of the system. The totes 19 are preferably rectangular boxes having a hinged cover. The totes must be sized such that they can readily be manually moved about within the delivery trucks and retail stores. By way of example, a suitable size is 16" x 22" x 10". Each tote has an identification indicia 37 that individually identifies the particular tote. The identification indicia 37 may take the form of bar coded labels. In alternative embodiments the totes may take the form of cases of particular products. VERTICAL QUEUE Referring next to Figures 5-20, the embodiment of vertical queue 11 chosen for the purpose of illustration, will be described. As best seen in Figures 5-7, vertical queue 11 comprises an endless progression of shelves 111 spaced about an opposing pair of endless loops 108 for traveling around a frame 112. The endless loops may be driven by an electrically or hydraulically operated motor 117. The opposite ends of shelf 111 are each attached to one of the opposing endless loops by brackets 113 and suspension struts 114, 115. As can be seen in Figures 6 and 8, each end of each shelf 111 has a pair of suspension struts 114, 115 of appropriate length that are secured from the front and back edges of the shelf respectively to the corresponding brackets 113 by a pivot point 116 so that the shelves are pivotably supported by the struts in a substan¬ tially horizontal orientation. A support rod 120 which extends the length of the shelf joins the suspension struts to. their corresponding bracket and therefore forms the rotational axis of the pivot point. The pivotal mounting causes the shelves 111 to always hang below the bracket and support rod in a substantially horizontal orientation so that the containers may ride with the shelf as the shelf passes over from its up travel reach to its down travel reach. To ensure that the shelves remain substantially horizontal when passing over the top and bottom ends of the endless loop, top and bottom guide channels 121 and 122 respectively are provided for each endless loop 108 to cooperate with guide tubes 123 fixedly mounted on opposite ends of the support rod 120. Each guide tube 123 carries a roller 124 at its free end and a single guide tube 123 5 extends obliquely downward from each end of the support rod 120 in opposite directions relative to the vertical axis. (Figure 8) As can be seen in Figures 5 and 20, the guide channels 121, 122 define a semi-circular path equivalent to the arc that the shelves must follow when passing between 10 the up travel reach and the down travel reach along the endless loop, together with a pair of stub arms 125 that define a portion of the up and down travel reaches of the shelves. The channel portion 127 of the guide channels is sized to closely receive the guide tube roller 124. The 15 open end of each stub arm 125 includes a substantially trapezoidal funnel portion 126 that acts as a funnel entrance to the channel portion 127 that ensures the rollers 124 will enter the channel portion as they begin to pass over the top or bottom ends of the vertical queue. Since Zσ the guide tubes 123 are fixed relative to the support rod 120, each guide tube 123 together with its roller 124 will cooperate with the top and bottom guide channels 121, 122 to ensure that its corresponding shelf will remain substantial¬ ly horizontal as it passes over or under the queue by 25 pivoting about pivot point 116 as previously mentioned. This action ensures that containers will not slip off of their shelves as they pass over or under the queue. Referring next to Figure 8, each shelf includes a frame 129 that supports a pair of side by side holding sections 30 130. Each end of the- frame comprises a triangular support formed by suspension struts 114 and 115 together with riser 131. A plurality of struts 132 extend between the opposing risers 131. The holding sections 130 are formed of a plurality of aligned low friction rollers 118 that extend 35 between riser members 133. The riser members are securely fastened to struts 132 in a manner that allows low friction roller 118 to freely rotate. To prevent containers from floating around on the shelves, at least one of the rollers 118 takes the form of a ratchet roller that resists backward movement of the containers. In the embodiment used for the purpose of illustration, movement onto and off of the shelves is gravity motivated. Thus, the shelves are constructed so that each has a permanent tilt. This may be seen in Figure 6 with the right hand sides being slightly higher than the left hand sides. Low friction rollers 118 on the shelves support the con¬ tainers 25 in a potentially slidable condition. Shelf blockers 119 hold the containers on the shelves until they are ready to be released. With shelves arranged in this fashion, containers are received on one side of the vertical queue while they are be released on the opposite side. As can best be seen with reference to Figure 8, the suspension struts 114, 115 project slightly outwardly as they extend riser 131 to support rod 120. The slant in the suspension struts give the entire shelf a trapezoidal shape that facilitates stacking. A pair of opposing guide members depend from each of the risers 'to form a rounded V-shaped guide that receives the support .rod from the shelf disposed immediately beneath it. The vertical spacing between the shelves is adjusted such that when a shelf in on either the up or down travel reach about its endless loop path, its support rod will be closely held within the apex of the V- shaped guide depending from the shelf positioned immediately above, while its own guide closely receives the support rod from the shelf disposed immediately below. This interlock¬ ing of the shelves prevents the shelves from swinging back and forth while they are outside the influence of guide channels 121 & 122. Since the containers may carry several hundred pounds of materials and the loading ramp 20 that feeds the vertical queue is gravity motivated, the containers may be traveling with a great deal of momentum as they are loaded onto a shelf. To reduce the impact with which the containers strike the shelf blocker 119 during loading operations, a soft stop mechanism 136 is provided for absorbing a substan¬ tial percentage of the containers momentum. A soft stop mechanism 136 is mounted to the vertical queue frame 112 adjacent each of the loading ramps 20. Referring specifically to Figures 8 and 9, the soft stop mechanism are disposed within the endless, loop that defines the travel of the shelves 111 and operates substantially as a scissor type shock absorbing device. It includes a strike bar 137 having a plurality of shock absorbing compressible pads 138 thereon, a support rod 139, a pair of shock absorbers 140 and 141 and a plurality of connecting members 142-144 for connecting the various components. Members 142 and 143 are pivotally coupled to each end of the strike bar 137. A first end of member 142 is pivotally coupled to the strike bar and its opposing end is slidably coupled to a slot 148 in frame element 149. Member 143 is substantially L-shaped and is pivotally coupled to strike bar 137 on a first end, shock absorber 140 on its opposite end and member 144 at its joint. Member 144 is pivotally mounted to the support rod at an intermediate point while its ends are pivotally mounted to the opposite end of shock absorber 140 and the joint portion of "the L-shaped member 143 respec¬ tively. Shock absorber 141 is connected to a similar structure at the opposite end of the strike bar. Members 142 and 143 are identical for the opposite ends, while the geometry of member 144 is varied between the two ends such that the alignment of shock absorbers 140 and 141 are varied as shown in Figures 8 & 9. Such an arrangement enhances the shock absorbing characteristics of the soft stop 136. It should be appreciated that the soft stop mechanism must be fully withdrawn when the vertical queue is rotated so that it does not interfere with the shelves. To facili¬ tate fully withdrawing the soft stop, the shock absorbers 140 and 141 are both pneumatic cylinders that take a collapsed position when they are not pressurized. When the pneumatic shock absorbers 140,141 are in the collapsed position, the entire soft stop mechanism rests inside of the endless loop defined by the travel of shelves ill. When a container positioned on loading ramp 20 is ready to be loaded onto a properly positioned shelf 111, the pneumatic shock absorbers 140,141 are pressurized thereby extending the strike bar 137 to a position slightly upstream from the shelf blocker 119. Thus, when the container 25 strikes the soft stop mechanism 136, the shock absorbers dampen its kinetic energy. The strike bar is then slowly retracted by releasing pressure from the pneumatic shock absorbers thereby allowing the container to position itself slowly against the blocker 119. The weight of the container helps compress the shock absorber as pressure is released. Although the described embodiment of the loading ramp 20 and the shelves 111 incorporate are tilted to facilitate gravity motivated loading and unloading, it should be appre¬ ciated that equivalent mechanisms may be constructed that eliminate the . need for tilting by incorporating power operated traction rollers or various actuators to transfer the containers onto and off of level shelves on the vertical lift. With such arrangements the need for a soft stop mechanism as described above would be eliminated. Referring next to Figures 10-17, the construction of the drive mechanism will be described that is responsible for rotating the shelves about the vertical queue in an endless loop. To facilitate explanation, the entire drive arrangement will be described as it applies to one side of the vertical queue. However, it should be appreciated that identical structures are provided on each side of the vertical queue. Each endless loop 108 comprises a compres- sion chain 150 formed of a multiplicity of pivotably coupled linkage bars 151,153 that travel about a guide track 152. The linkage bars (see Figure 17) alternate between inner linkages 151 and outer linkages 153 that are pivotably coupled together by an axle 154 disposed between a pair of spaced apart equally sized tapered guide rollers 156. The rollers 156 (as shown in Figure 16) are adapted to travel about the guide track 152. The brackets 113 are fixedly mounted to the axle 154 by a mounting member that forms a shoulder " 155. Two brackets 113 are provided to support each shelf. Only one bracket 113 is attached to each axle 154 and the brackets are arranged such that they combine with one of the linkage bars to form a triangular support for the shelf. As will be apparent from the description below, it is important to the operation of the drive mechanism that each linkage bar be the same length. Each of the inner linkage bars is formed by a pair of spaced apart equally sized plate members 157 coupled by a support element 149 and a pair of tubular members 159 adapted to receive axle 154. The outer linkage bars have apertures 148 adapted to align with tubular members 159 to receive the axle 154 and form a pivot point with the adjacent inner linkages. The outer linkage bars also have supports similar to support elements 149 to increase the strength of the compression chain. Referring specifically to Figures 13-15, the guide track 152 is carried by a tower 158 which carries much of the structural load of the vertical queue. The guide track itself is formed of a pair of vertically extending track portions 161 that are mounted to opposite sides of an I- beam. Each track portion comprise a pair of spaced apart, facing U-shaped members 160 adapted to receive the rollers 156. An opening is provided between the U-shaped members 160 that is wide enough to receive the linkage bars 151,153 and the bracket 113 and still leave enough room for the drive weldments described below to access the shoulder 155 on axle 154. The top and bottom ends of the guide track are left open so as to allow the linkage bars to rotate about the ends without interference. It should be appreciated that as the linkage bars rotate about the ends, their associated shelves are being guided about the end by the interaction between guide tube 123 and guide channels 121 or 122 as previously discussed. - To drive the compression chain in a continuous loop a drive mechanism 170 is provided as will be described with reference to Figures 10-12. The drive mechanisms 170 on opposite sides of the vertical queue may be driven by a common motor. Each drive mechanism is incorporated into a removable unit that is attached between segments of the I- beam. A pair of identically sized spaced apart endless drive chains 171 each extend about a three gear set compris¬ ing a drive gear 172, a spacing gear 173 that is sized identically with the drive gear and a reduced sized idler sprocket 174 as seen in Figure 10a. The two drive chains and their associated gear trains are mirror images • of one another. Therefore, the drive mechanism will be described by reference to a single drive chain 171 although it should be appreciated that the described structure is duplicated in actual practice. The drive gears 172 are carried by an axle 176 that is driven by motor 117. The drive chains 171 are comprised of a plurality of links 178 interspaced with a plurality of equally spaced apart brackets 179. The brackets 179 carry a rod 180 that extends between the two drive chains. Each rod is pivotally coupled to a weldment attachment 182 by a tubular member 183 that is aligned perpendicularly with the plane of the weldment 182. The weldments 182 are all identically sized and it is important that they be equally spaced about the drive chain. As can be seen by reference to Figure 11a, each weldment is symmetrical about its vertical axis and includes a pair of opposing notches 185 adapted to engage the shoulders 155 of axles 154 that couple the linkage bars of the compression chain 150. The drive mechanism 170 is positioned within the endless loop 108 such that the weldment attachments may engage the underside of adjacent endless loop axle shoulders 155. The drive mechanism includes five weldment attachments dispersed about the drive chains 171. The gears 172-174 are sized and spaced such that at least one of the weldments will engage a linkage bar on the up travel reach and at least one of the weldments will engage a linkage bar on the down travel reach of the endless loop at all times. Ref rring next to Figures lie & lid, the orientation of the weldments as they travel about the path of the drive chain will be described. To facilitate a reversible drive assembly, the weldments - must be maintained in a substan- tially vertical orientation as they travel about the loop formed by drive chain 171. To maintain the weldments in the upright position, a guide roller 186 is provided on the free end of the weldment, and an alignment notch 187 is provided on its bottom end. The guide roller is adapted to engage a guide channel 189 disposed vertically above the drive mechanism 170 when the bracket 179 that connects the weldment to the drive chain engages the drive gear 172. The contour of the guide channel 189 is arranged to ensure that the weldment falls gently away from the link bar axle it carries on an up travel reach as the weldment is rotated about the end of drive gear 172. The guide channel 189 is symmetrically shaped so that it serves to gently position the weldment under a linkage bar axle on its down travel reach as the weldment completes its journey about the drive gear 172. The alignment notch 187 works in combination with the support notches 185 to perform the same function as the weldment passes about the lower end of the drive mechanism. As can be seen by reference to Figure lid, the weldment begins to fall away from supporting engagement the link bar axle it carries as it passes by spacing gear 173 on a down travel reach. As the link bar is disengaged from the support notch 185, the vertical surface 188 of the support notch 185 rests against the link to prevent the weldment from flopping loosely. As the weldment approaches the idler sprocket 174 the alignment notch is engaged by an alignment pin 184 positioned directly under the idler sprocket 174.. The geometry of the alignment notch and the positioning of the alignment pin 184 are arranged such that the weldment will flop to the opposite side such that it no longer rests against a link bar on the down travel reach, rather the vertical surface 188 of the opposite support notch 185 rests against a link bar on its up travel reach. As the drive chain continues to rotate, the support notch in contact with the link bar on an up travel reach is then gently rotated into a supporting position underneath the link bar. Preferably the motor 117 is reversible so that the shelves may be rotated in either a clockwise or a counter¬ clockwise direction. With such an arrangement, when a request is made for a particular container, the queue may be rotated in the shortest direction to the release point. It should be appreciated that the symmetrical guide channel and alignment notch geometries described facilitate the use of a reversible drive motor since changing directions of the drive cable will not adversely affect the positioning of the weldment. SUPPLY CONVEYOR Referring specifically to Figures 1 and 7, the supply conveyor section 12 may be provided with one or more transfer stops 90 for transferring containers from the supply conveyor to an adjacent loading ramp. There are a wide, variety of conventional right angle transfer assemblies for conveyors that may be used to form transfer stop 90. In an embodiment of the transfer stop chosen for the purpose of illustration, each transfer stop has a plurality of trans- versely disposed traction rollers 92 mounted at longitudi¬ nally spaced locations along the conveyor section 12 leaving spaces 93 between the rollers. Power driven endless belts 95 which are disposed within the spaces 93 may be selective¬ ly activated to divert containers onto the loading ramp 20. A power operated alignment stop 97 is provided at the end of each transfer stop to ensure that the containers to be diverted to the adjacent loading ramp 20 are properly positioned. Thus, when a container is delivered to a particular transfer stop 90, its associated alignment stop is raised and the container is carried by traction rollers 92 until it abuts against the alignment stop. A presence detector 23 can be provided to detect the presence of a container within the transfer stop. After the presence detector verifies that the container is properly positioned, the traction rollers may be turned off. In the embodiment shown in the Figures, the loading ramp is gravity motivated. With such an arrangement, loading ramp 20 is tilted toward the vertical queue 11 and is comprised of a plurality of transversely arranged low friction rollers 162. A power operated stopper 164 which may be pneumatically operated holds the containers until they are ready to be loaded onto the vertical queue 11. When the container 25 is loaded onto the vertical queue 11, the queue is rotated until an empty shelf is positioned adjacent the loading ramp 20 and momentarily stopped. The power operated stopper 164 is released and the container rolls freely over the low friction rollers 162 and 118 onto the shelf until it strikes soft stop mechanism 136. Then, as previously described, the container is gently lowered into abutment against the shelf blocker 119. The soft stop mechanism 136 will absorb much of the containers momentum as previously described. Although in the embodiment shown in Figure 5, loading ramp 20 is tilted to facilitate gravity motivation, it should be appreciated that the loading ramp can readily be adapted to facilitate substantially horizon¬ tal insertion. This can be accomplished by replacing the low friction rollers with power operated rollers or by adding an actuator assembly capable of pushing containers onto the vertical queue to perform the same function. When a container 25 is 1 to be unloaded from the vertical queue, the queue is rotated until the appropriate shelf 111 is positioned adjacent the delivery system 14 and momen- tarily stopped. The appropriate shelf blocker 119 is released, thereby releasing the container which due to the tilt in the shelf 111 rolls freely across low friction rollers 118 onto the discharge station 40 of delivery system 14. It should be appreciated that the shelves may be substantially horizontal an outfitted with the traction rollers to accomplish the same function. Conventional side stopper arrangements are located on the side of the discharge station opposite the exit points for the vertical queue to insure that the discharged containers remain on the delivery conveyor without damaging either the containers or the conveyor. The discharge stations themselves may be conventional right angle transfers that include three sets of spaced apart roller wheels that are disposed between traction rollers of the delivery conveyor. In such an arrangement the conveyor for the delivery system is disposed a few inches below the position at which the shelves are stopped when they discharge the containers. The ends of the roller sets closest to the vertical queue are tilted upward when a container is to be discharged such that the end substantially matches the level of the adjacent shelf edge, thereby providing a smooth ramp for the container to flow over when it is released. Referring next to Figure 21, a suitable construction for power operated stopper 164 will be described. In embodiments that incorporate the gravity motivated loading ramp 20, the power operated stopper must act as a shock absorber that absorbs the momentum of containers incident thereon without bouncing the containers back towards the transfer assembly. The power operated stopper includes a pair of dogs 165 pivotally coupled to opposite ends of one of the low friction rollers 162. A rubber strike roller " 166 is rotatably coupled to the free end of dogs 155. A pair of side by side hydraulic pistons 167 are coupled between each dog and a fixed brace 168, as shown in Figure 21 such that when the pistons are extended, the strike roller 166 is in an upright position that block the container path. When the hydraulic rams are withdrawn, the strike roller 166 is pivoted into the plane of the low friction rollers 162 and since it is rotatably mounted to the dog, the strike roller functions as just another roller for the loading ramp. The hydraulic pistons function as shock absorbers that receive the impact of the containers as they slide down the loading ramp. Referring next to Figure 22, a suitable construction for the shelf blockers 119 will be described. Since the power operated blockers only need to be released when their associated shelf is disposed adjacent the delivery system 14, the mechanism for actuating the blockers 119 may be mounted in a single location on either the delivery system or the vertical queue. A pnuematic piston (not shown) activates push rod 280 when a container is to be released. The push rod 280 is mounted to the vertical queue frame 112. The blocker 119 includes member 282 which is pivotally mounted to the the shelf riser 131 at its lower end. The upper end of member 282 carries a low friction roller 284. When a shelf is disposed adjacent the discharge station 40, the push rod 280 may be activated. When activated, the push rod 280 strikes the lower portion of member 282 thereby causing the member 282 to pivot about a pivot point which drops roller 284 from the raised position shown in Figure 22 to the lowered position shown in the same drawing. The lowered position is in line with the other low friction rollers 118 on shelf 111. A compression spring 285 is mounted between the push rod 280 and a frame element 287 attached to frame 112. The compression spring returns the push rod 280 to the contracted position when pressure is let off of the pnuematic piston. Si iliarly, a return arm. 291 is connected on a first end to member 282 and on a second end to spring 293. The opposite end of the spring is mounted to a bolt 295 in shelf riser 131. Spring 293 is arranged to return the member 282 to the upright position when pressure is let off of the pnuematic piston. In the embodiment described for the purpose of illus- tration, the vertical queue 11 is adapted to receive two side-by-side containers on each shelf. The throughput of the vertical queue can readily be varied by altering the width of shelves ill to accommodate various numbers of containers on each shelf and providing the appropriate numbers of loading ramps 20 and discharge stations 40. To further increase the operational rate of the queue, multiple vertically aligned loading and discharge systems may be provided as well. The delivery system is essentially a conveyor network adapted to delivery the containers to an appropriate work table. The delivery system 14 may include a supply stop 190 for each work table. The supply stops 190 may be con¬ structed similarly to the transfer stops 90 or the right angle transfers previously described. Each supply stop retains a particular container until the loading ramp for the work table 7 with which it is associated is ready to accept that container. The construction of the loading ramps for the work tables may be identical to the loading ramps 20 previously described for the vertical queue. ROTATABLE WORK TABLES The work tables 7 are adapted to automatically receive and discharge containers and are positioned such that an operator can readily access the contents within the con¬ tainer 25 that is sitting thereon. As seen in Figure 3, the embodiment of the work center described is arranged such that the delivery conveyor of the delivery system 14 is positioned directly above the takeaway conveyor of the takeaway system 16. Thus the work table 7 is adapted to received containers at one level and discharge containers at a second level. However, it should be appreciated that the positions at which the work tables receive and discharge containers, as well as the actual construction of the work tables 7 may be widely varied within the scope of the present invention. Referring next to Figures 3 and 23-31, the embodiment of the work table chosen for the purpose of illustration will be described. The work table 7 includes a frame 302 having two front posts 304 and two rear posts 306 that are coupled by a plurality of frame members 303. The posts are tubular and arranged in a rectangular fashion. The -posts are secured to the floor of the work area and frame members 303 extend between adjacent posts to provide the necessary support. A rotatable platform 309 is carried by a substan¬ tially rectangular base 310 that is slidably coupled to the frame posts 304,306. A drive motor 312 carried by base 310 rotates the platforms 309 about a substantially vertical axis. The base 310 is formed by a pair of parallel beams 311 that are coupled by a plurality of risers 313 (see Figure 27) . The beams 311 extend along opposite sides of the frame 303 between one of the front posts 304 and a corresponding rear post 306. Each corner of the base 310 is connected to one of the posts by a sleeve 315. Each sleeve 315 is slideably coupled to an associated post and attached to a drive chain 314 that may be selectively driven to raise or lower the sleeve with respect to its corresponding post. Referring next to Figure 24, each post has a drive chain 314 arranged as a vertically extending endless loop between a drive sprocket 330 on its top end and an idler gear 332 on the bottom. The drive chain 314 travels through the tubular post on one of its reaches and outside the post on its opposite reach (although for safety the portion of the chain outside the operational traveling distance of the platform may be protected by a shroud) . The sleeves 315 are each attached to the outer reach of their associated drive chain. The drive sprockets 330 for the drive chains associated with the front posts are mechanically coupled by a drive bar 316. A similar drive bar couples the rear sleeves in a similar fashion. The drives bars 334 are driven by independent reversible motors 336. Thus, the movements of the front sleeves are mechanically coupled, as are the movements of the back sleeves. It will be appre- ciated that the platform 309 may be raised by moving all four of the sleeves simultaneously, or it may be tilted by independently moving the front or rear sleeve pairs. Referring next to Figures 25 and 26, the parallel beams 311 of base 310 are pivotally coupled between the front posts 304 and the rear posts 306. As can be seen in Figure 25, the front ends of beams 311 are simply pivotally mounted to their corresponding sleeves 315. In order to allow the front and back sides of the platform to move independently, a pair of lever arms 317 are provided to pivotably connect the base to the rear post sleeves to provide the necessary slack during tilting. As can be seen in Figure 26, a first end of each lever arm is pivotably connected to one of the beams 311 in base 310, while the second end of the lever arm is pivotably connected to the associated rear sleeve. Thus, the front and rear ends of base 310 can move independently with lever arm 317 providing or absorbing the necessary slack. The platform 309 best seen in Figures 23 and 28 carries a gate 321, a plurality of rollers 323, side rails 325 and a pair of stoppers 327. The platform itself is substantially square with the axis of rotation of rollers 323 extending perpendicularly to side rails 325. In the embodiment chosen for description, the delivery system 14 is disposed substan¬ tially above the takeaway system 16. Thus, when a container 25 is delivered to the rotating work table the platform is raised to the height of the delivery system. The gate 321 and a power operated stop 164 on the adjacent loading ramp 20 are both dropped and the container is guided by side rails 325 as it passes over the rollers 323 until it is stopped by the stopper 327. The gate 321 is then raised to prevent the container from slipping off the platform. To facilitate transferring the container from the loading ramp 20 to the platform 309, rollers 323 may be either power operated or low friction. Low friction rollers are appro- priate if loading ramp 20 is slightly inclined to provide gravity motivation. With the gravity motivated system, the first roller 324 may be a breaking roller to slow down the container as it enters the work table platform. Alterna¬ tively the braking roller may be provided as one of the last rollers of the loading ramp to accomplish the same function. Platform 309 is rotatably mounted to base 310 on a circular track 340 carried by beams 311, 313 and a rotatable shaft 341. See Figure 27. A plurality of rollers 360 are mounted to the bottom side of platform 309 to travel about the circular track 340. The circular track 340/rollers 360 arrangement is particularly useful for supporting unbalanced loads, as will be frequently encountered with partially full containers. A geneva drive system 342 driven by electrical motor 312 rotates the platform as necessary. The geneva drive (shown in Figures 29 & 30) is substantially conven¬ tional and includes a square plate 344 having a roller 346 extending upward from each of its corners. The plate 344 is mounted on the base 310, and is chosen to have four sides so that each of the sides of the square containers can be presented to the operator. The rollers 346 are designed to engage channels 350 on the lower side of platform 309. As can be seen in Figure 29, the channels 350 form a pair of perpendicular lines that intersect at the axis of rotation of. the platform about shaft 352. The platform is properly pos t one s ow ng one o s s es w en wo o e ro ers 346 engage their associated channels 350 as seen in Figure 29. It should be appreciated that such an arrangement provides a great deal of stability in its fixed presentation positions and that rotational movement between the presenta¬ tion positions is sinusoidal. Each channel is formed by a pair of parallel members 351. The plate 344 is driven by a belt 348 that in turn is coupled to the drive shaft 349 of motor 312. Before a container can be placed on the work table, the gate 321 must be dropped. A wide variety of conventional mechanisms can be provided as the gate and the means for raising and lowering the gate. A suitable construction is shown in Figure 31. The gate 321 takes the form of an L- shaped member that rests upon a moveable block 380. The moveable block is coupled to the end of a extended rod 381 that passes through a couple of apertures 382 in the walls of circular track 340. A hand operated lever 383 mounted to the front side of base 310 is pivotally coupled to the other end of rod 381. A compression spring 384 is biased to press against the rod 381 to press the moveable block 380 towards the rear of the platform. When the work table is sitting in a position such that the gate 321 is adjacent the loading ramp, the handle 383 is disposed right in front of the operator. To drop the gate, the operator pulls the handle 383 which moves block 380 out from underneath the gate member 321 thereby dropping the gate. Once a container is placed on the work table, the height of the platform is adjusted to suit the particular operator and the platform is tilted towards the operator to provide better access to the interior of the container. Tilting is accomplished by raising the rear sleeves relative to the front sleeves. To ensure operator comfort, it is generally desirable to adjust the platform to approximately waist height and tilt the table in the approximate range of 15-30° toward the operator. In a fully automated system, when an operator is prepared to begin work, he logs into the controller which verifies that the operator is authorized to work this station. The operators height may be inputted into and remembered by the controller which can then vary the level at which the containers are presented to the operator to match the height of the particular operator. Each work table is provided with a signal light 375 and a pushbutton 370. The signal lights are controlled by the system controller to light up over the active table. After the operator is finished with an operation, he hits a pushbutton 370 which informs the controller that the designated task is complete. If other items within the container are to be distributed or items are to be placed in other compartments, the platform is rotated to the appro¬ priate position. If the container will not be used any more, the platform is rotated to its neutral positioned, lowered to the level of the takeaway system 16 and tilted such that the back side of the platform is lower than the front. The gate 321 is then dropped and the container is released. Again the container transfer may be accomplished either through the use of power operated rollers or by slightly inclining the platform towards the takeaway system. CONSOLIDATION QUEUE The consolidation queue 18 is positioned adjacent to work area 5 such that an operator may conveniently work between the consolidation queue and the work tables 7. Structurally, the consolidation queue may take a form very similar to the vertical queue 11, with the primary differ¬ ences being in the loading and unloading mechanisms, the shelf sizes and the containment mechanisms for keeping the totes on the shelves. Referring next to Figures 4 & 32-38, the embodiment of the consolidation queue chosen for the purpose of this description comprises an endless progression pf horizontally oriented pans 410 spaced along an opposing pair of endless loops 408 which may take the form of compression chains, for travel about a frame 412. The respective ends of pans 410 are attached to one of the opposing compression chains by brackets and suspension stru s ust as the shelves of the vertical queue are connected to their respective endless loops. Referring primarily to Figures 32 & 35, each end of each pan 410 has an associated pair of suspension struts 414, 415 of appro- priate length that are secured from the front and back edges of the pan to the corresponding bracket 413 by a pivot point 416 so that the pans 410 are pivotably supported by the struts. The pivotal mounting causes the pans 410 to always hang below the bracket and the pivot point in a substan- tially horizontal orientation so that the totes 19 may ride with the shelf as the shelf passes over from its up travel reach to its down travel reach. The endless loop 408 may be driven by an electrically, pneumatically or hydraulically operated reversible motor 417. Thus, the consolidation queue may be rotated in either direction. Two shelves 411 are suspended from each bracket/- suspension strut arrangement as can be seen in Figure 35. It should be appreciated that in alternative embodiments, the pans 410 may readily be constructed so that only one or more than two shelves 411 are suspended from each bracket. The two shelve construction is advantageous in the consumer products distribution application described above because it facilitates standardization of parts between the consolida¬ tion queue and the vertical queue. The standardization is possible since the totes are on the order of one-half the height of the described containers which allows many common components between the two queues. Each shelf includes a riser 421 on each end of the shelf that is secured between suspension struts 414, 415 to provide a triangular frame that supports the shelf. (Figure 32) . A plurality of struts 422 extend between opposing risers 421 to form the base of the tote pads 419. The upper sides of. struts 422 are rounded to provide a low friction surface over which the totes may readily pass. Shelves 411 are sized and arranged so that the plu¬ rality of tote 19 may be placed side-by-side on each shelf. Preferably, ' each shelf includes a plurality of tote pads 419, each of which receives a single tote drawer 19. Spacers 420 extend perpendicularly across the upper surface of the shelves to separate the various tote pads and to hold the totes in place. By way of example, in a large scale consumer products warehousing application as previously described, a suitably sized consolidation queue 18 may have approximately 40 shelves with each shelf holding about 10 tote drawers. In such a system 20 suspension/bracket arrangements would be provided about the endless loop 408 with each suspension/bracket arrangement supporting two shelves. Alternately, the consolidation queue can be configured to carry a plurality of either full sized or downsized containers 25 on each shelf. Such an arrangement is desirable particularly in distribution systems wherein consolidated or kited goods are to be returned to a storage carousel for storage rather than delivered for immediate shipping or production use. Referring next to Figure 33, the endless loop compression chains 408 comprises a multiplicity of pivotably coupled linkage bars that travel about continuous guide track. The linkage bars and guide track may take a form identical to the linkage bar and guide track arrangements previously described with respect to the vertical queue 11. Similarly, a drive mechanism that rotates the compression chain 408 and guide channels that ensure the shelves remain substantially horizontal as they pass over the top or under the bottom of the consolidation queue 18 may also be identical to the corresponding components of the vertical queue. The front face of the consolidation queue includes a fixed loading shelf 430 that is mounted on the frame 412 and protrudes outwardly towards the operator at about waist level. As seen in Figure 34, a plurality of pneumatic rams 431 are disposed opposite the fixed loading shelf 430 within the open interior portion 432 of the consolidation queue between the shelves on an up travel reach and those on a down travel reach. The actual number of pneumatic rams will correspond to the number of tote pads carried by each shelf 411, with each ram being associated with a particular one of the tote pads 419. The pneumatic rams are positioned such that when one of the shelves 411 is positioned adjacent a fixed loading shelf 430 and a particular ram is actuated, the actuated ram will push its associated tote drawer 19 onto the fixed loading shelf 430. . Since the totes must be pushed fully onto the fixed loading shelf to allow the operator to close their lids when an order is complete, and since the width of open interior area 432 is relatively small, pneumatic rams 431 are multi¬ stage ram arrangements as can be understood by reference to Figure 34. The pneumatic rams have a first stage 443 having a fixed stroke and a second stage 445 having a variable stroke. The first stage is fixably mounted to the carrier 446 of second stage 445 such that the entire first stage moves with any movements of the second stage. A plunger 447 having a large surface area strike plate 448 is positioned such that when it is actuated, the strike plate will engage the tote positioned on the adjacent tote pad and push it onto the fixed loading ramp 430. Suitable rams for both the first and the second stages are produced by Bimba Manufacturing Co. of Monet, Illinois. In operation, it may be desirable to vary the amount that a tote is pushed out based upon the status of the order it is receiving. Thus, for example, it may be desirable to push the totes three fourths of the way out for normal loading operations, but all of the way out when the last item is being placed into the tote in order to facilitate closing the totes lid. In such a system, pushing the tote all of the way out onto the fixed loading shelf may be used as a signal 'that informs the operator to close the tote's lid. A front panel 433 is attached to the front exterior side of frame 412 to cover the front portion of the con- solidation queue. (Figure 6) . The panel 433 includes an opening 434 that receives the fixed loading shelf 430 and is sized suitably to allow tote drawers 19 to open onto the fixed loading shelf. The panel 433 serves to protect the operator by preventing loose goods from falling off of the consolidation queue. A track 437 is disposed on the front surface of panel 433 somewhat above the opening 434. A carriage 436 that carries a printer 435 and a bar code scanner 439 is mounted on the track for movement back and forth thereon. The printer carriage and track arrangement may be conventional components. " As will be described below, the control system 17 is devised such that it is capable of moving the carriage 436 back and forth along the track 437 so that the printer 435 and bar code scanner 439 may be positioned over any one of the opened tote drawers 19. After all of the goods destined for a particular tote have been loaded therein, the printer 15 is positioned over the loaded tote and prints the required shipping invoices. The bar coded scanner 439 may be used to identify inventoried goods placed into or taken out of the consolidation queue. This is particularly useful when the consolidation queue is being used in the context of a receiving station or when unidentified or misplaced goods are found in the containers. To fill a particular tote drawer 19, the shelf on which the tote drawer is located is rotated until it is positioned adjacent the fixed loading shelf 430. The pneumatic ram 431 disposed adjacent the chosen tote is then actuated, thereby pushing the tote onto fixed loading shelf 430. A plurality of video displays 52 may be positioned on the front panel 433 above the opening 434 but below the printer track 437, with a single video display being associated with each tote drawer position. The video displays would generally be directed by the control system to display instructions to the operator as to the identity and quantity of goods to be placed in the open drawer. The video displays may take the form of conventional LED or LCD displays or the like. The printer 435 is automatically positioned above the open tote drawer simultaneously with its opening and when appropriate . places the desired goods in the open drawer, the invoice is taken from the printer and placed in the drawer. The drawer is then manually closed. It will be appreciated that a separate invoice may be printed for each transaction as individual items are placed into the tote, or a single invoice may be printed after all of the ordered items have been placed in the tote. The consolidation queue 18 may be loaded with empty totes via a wide variety of mechanisms which may be either manual or automatic. In the embodiment shown in Figure 36, a tote supply conveyor stub 450 is disposed adjacent the front surface of consolidation queue 18 above the printer 435 at a height that is within the operator's reach. Empty totes are provided to the conveyor stub 450 in a convention¬ al manner. With such an arrangement, a plurality of totes will typically be available on the conveyor stub within the operator's reach. The operator is responsible for grabbing empty totes off the conveyor stub 450 and inserting them onto empty tote pads 419 adjacent the fixed loading shelf 430. As will be described below, the totes 19 may be loaded onto the shelves of the consolidation . queue either as a batch or in a prompted manner as needed, depending upon re¬ quirements of the system. As each tote is placed on its shelf, its discrete identification indicia 37 (which takes the form of a bar coded label) is read by the bar code scanner 439 and recorded by the work center controller 500 in a tote inventory file 526. Drawers 451 are provided below fixed loading shelf 430 to temporarily store particular goods as needed. In an alternative arrangement, the conveyor stub may be replaced with a continuous conveyor (not shown) , that remains in continuous motion carrying totes past the front of the consolidation queue. The passing totes are then be selectively picked for insertion onto the consolidation queue as needed. Alternatively an insertion structure may be provided along the back side of the consolidation queue for mechani¬ cally loading the totes. Referring next to Figure 37, a suitable automatic tote loading arrangement will be de- scribed. A conveyor stub 452 delivers empty totes 19 to the consolidation queue. A loading track 456 is provided for transferring totes 19 from conveyor stub 452 to the shelves of the consolidation queue. The loading track travels in an endless loop disposed adjacent the back side of the consolidation queue, preferably at a level different from the level of the fixed loading shelf 430 and its associated rams 431. The loading track has a plurality of tote carrying locations and is adapted acurately position any one of the tote carrying locations in front of any particular shelf tote pad 419 on the shelf 411 disposed adjacent the track. A plurality of loading rams 473 are disposed behind the loading track to transfer totes from the loading track to the consolidation queue 418. Alternatively, the loading track may be replaced by a carriage (not shown) that transfers totes 19 from the conveyor stub 452 to the shelves of the consolidation queue. The carriage is mounted on a track disposed is place of the loading track. The carriage is adapted to move back and forth along the track so that it may be positioned adjacent any one of the various tote pads 419 on the active shelf. The carriage includes a pair of transfer pads, each of which receives a single tote 19.- Each "transfer pad includes a power driven endless belt, a pair of gates located on opposite sides of the endless belt, and an actuator arm. A presence sensor detects when a tote is properly positioned on the transfer pad. A reversible motor (not shown) , is provided to drive endless belt in either direction. 1 To load containers onto the consolidation queue, they are first delivered to conveyor stub 452 in a conventional manner. A conventional alignment device (not shown) , ensures that the containers are delivered to the conveyor stub substantially perpendicularly to the loading track or carriage. The end of the .conveyor stub includes a transfer stop 470 for loading totes onto the loading track or carriage. The transfer stop 470 may take a form similar to the transfer stops 90 described above, although they are sized appropriately for the totes. In the carriage arrangement, the two transfer pads may be loaded simultaneously. Once the carriage is loaded with empty totes, it travels along the track until one of the transfer pads is located adjacent a tote pad 419 onto which an empty tote is to be loaded. At that point, the opposite gate is dropped and both power driven endless belt and actuator arm are activated to transfer the tote 19 onto the adjacent tote pad 419. The carriage is then moved (if necessary) , to position the second transfer pad adjacent the tote pad onto which the tote it carries is to be loaded. The second tote would then be loaded in the same manner as the first. A wide variety of mechanisms may be provided to unload the consolidation queue as well. In an embodiment chosen for the purpose of illustration, a tote disposer conveyor stub 468 is provided along the back side of the consolida¬ tion queue behind loading track 456 at the same level as the loading conveyor stub 452. A plurality of multistage unloading rams 470 are disposed opposite the track 456 within the interior portion of the consolidation queue between the shelves on the up travel reach and those on the down travel reach. The actual number of unloading rams 470 will correspond to the number of tote pads 419 carried by each shelf 411, with each ram 470 being associated with a particular one of the tote pads 419. The unloading rams 470 are positioned such that when activated " , they will push their associated tote out onto the loading track 456. The loading track 456 then transfers the tote 19 to conveyor stub 468, which in turn carries the tote to its intended destination. The actual construction of unloading rams 470 may be identical to pneumatic rams 431 as previously described. In an alternative embodiment, tote disposal conveyor stub 468 may be placed ' directly adjacent the back side of the consolidation queue at a level distinct from either the • fixed loading shelf 430 or the loading conveyor stub 452. The unloading rams 470 would be disposed adjacent the disposal conveyor stub 468 for pushing totes directly thereon. The disposal conveyor stub 468 is disposed on a level separate from fixed loading shelf 430 only to provide more space for and better access to the rams 431 and 470 respectively. To increase the throughput of the consolida¬ tion queue multiple loading and unloading assemblies may be provided at separate levels. In some applications it will be desirable to ' place the consolidated goods into containers suitable for placement back onto a storage rack. In such systems the consolidation queue 18 is adapted to carry containers 25 (or downsized containers) in place of totes 19. In such an arrangement, only one shelf would be carried by each bracket/suspension strut arrangement. It should be appreciated that in some applications it may be desirable to place full cases of material directly onto the shelves of the consolidation queue in place of the totes. SHIPPING QUEUE In many distribution applications such as the consumer products warehousing application described herein, the totes must be delivered by truck to retail establishments located outside the distribution facility. To maximize efficiency, it is important to load the truck in the reverse order of the delivery stops it will be making. Therefore, it is desirable to provide the totes to the shipping dock in an order suitable for loading directly onto the delivery can be accomplished by selectively choosing the order in which totes are withdrawn from the consolidation queue 18. However, in high volume operations, the time delays involved in rotating the consolidation queue back and forth suffi¬ ciently to properly order the totes will become prohibitive if it is necessary to continue consolidation operations during unloading. Therefore, in high volume operations, there may be a need to provide a separate shipping station which automatically arranges the totes into an order suitable for loading directly onto delivery trucks. It will be appreciated that the actual construction of the shipping station may be widely varied. However, in an embodiment of the invention chosen for the purpose of illustration, a shipping queue 480 is provided having a construction substantially identical to the consolidation queue 18 previously described, except that there is no need for the fixed loading shelf 430, printer 435 or bar code reader 439. The shipping queue 480 may be loaded directly from the consolidation queue 18 by positioning the shipping queue directly behind the consolidation queue as shown in Figure 38. A fixed transfer shelf 482 is disposed between the two queues in place of the disposal conveyor stub 468 previously described. The unloading rams 470 in this embodiment take the form of multi-stage pneumatic rams having a total stroke long enough to push their associated totes over the transfer shelf 482 and onto a shelf on the shipping queue. Therefore, to transfer filled totes from the consolidation queue 18 to the shipping queue 480, the consolidation queue is rotated until a shelf 411 having filled totes is disposed adjacent the transfer shelf 482. The shipping queue is simultaneously rotated until an empty shelf is disposed adjacent the transfer shelf. The appro¬ priate unloading rams 470 may then be actuated to transfer selected totes between the two queues. It will be appreciated that the actual insertion and extraction assemblies, as well as the method of loading and unloading the shipping and consolidation queues may be widely varied. For example, the shipping queue may be arranged to both load and unload the consolidation queue. To facilitate loading the consolidation queue, the shipping queue can be provided with a plurality of multi-stage rams that face the transfer shelf 482. When actuated, the rams would to pass totes in the opposite direction across the transfer shelf from the shipping queue to the consolidation queue. The shipping queue itself may be loaded or unloaded using the same assemblies as previously described for loading and unloading the consolidation queue. To increase the throughput of the shipping queue, multiple loading, unloading and/or transfer assemblies may be provided at separate levels. OPERATION OF THE SYSTEM The work station components described may be used for a wide variety of purposes. For example, in warehousing applications, the work center may function as both a receiving station to receive inventory items into the system and as an issue station for consolidating customer orders. In production environments, the work center is used to receive inventory and to kit goods for production. By way of example, representative methods of operation will be described with respect to work centers adapted particularly for order consolidation and receiving functions in the consumer products environments previously described. ISSUE WORK STATION When an order is received, it is entered into a computer which searches an inventory record to determine whether the ordered goods are in inventory. In any given day several hundred customers place orders calling for any of 50,000 or more individual stock units, with the actual number of items requested for each stock unit varying widely. Therefore, in a large scale operation, a master computer would be used to organize the orders into related batches, with each batch corresponding to a family of related goods. By way of example, related families might sporting goods, etc. The orders can be filled in batches to optimize efficiency. If more than one work center is provided that may function as an issue station 60, then the batches of orders are distributed between the various operating work center as necessary to keep each operator busy. The issue stations 60 are arranged for efficiently con¬ solidating orders. When an operator is ready to begin filling orders, a container that carries ordered items is delivered to the work center. Each of the tote drawers 19 on consolidation queue 18 is designated to receive a specific customer order. It will be appreciated that in actuality a particular customer may have ordered enough goods to fill several hundred totes. However, as indicated above, rather- than sending each customer a truck load randomly containing the ordered goods, it is desirable to package the ordered goods for each customer in smaller lots of related goods. Consolidating the orders in groups of related goods facilitates rapid restocking at the retail stores when the goods are delivered. Therefore, the master controller organizes the ordered products into lots suitable for loading into the described totes. By way of example, the first product to be distributed may be aspirin. A specific container (which may be con¬ tainer #123) that carries aspirin is delivered to the vertical queue 16 within the work center. The container may also carry shampoo, toothpaste and other products within its various compartments. When an operator is prepared to begin consolidating orders, container #123 is delivered to one of the work tables 7. When the container arrives the signal light 375 over the selected work table lights up to indicate the active container to the operator and one of the tote drawers associated with an order that requires aspirin will be automatically opened. An instructional video terminal 50 is positioned adjacent the work tables in full view of the operator. The video terminal instructs the operator which items are to be distributed next and the quantity of units to be distributed in any given step. Similar information is presented on the appropriate video display 52 positioned above the open tote drawer. In the example given, aspirin is the first displayed item and the video terminal would inform the operator as to how many items of aspirin would be distributed. The operator may then pick the desired number -of units of aspirin and step over to the consolidation queue. The operator notices the number of stock units to be placed in the ' open drawer as verified by the appropriate video display 52 positioned over the open drawer and then deposits the requested number of boxes of aspirin into the open tote drawer 19. After depositing the appropriate amount of aspirin in the first drawer, the operator shuts the first drawer and another automatically opens with both the video terminal and the appropriate video display showing the number of units to be placed in the next drawer. If the operator is carrying enough aspirin the second drawer will be filled as well. When the operator runs out of aspirin, he steps back over to the container and retrieves some more. This cycle may be continued until either all of the aspirin within the container has been distributed or all of the pending orders for aspirin have been filled. It should be appreciated that the consolidation queue will have to be periodically rotated to position its various shelves adjacent the fixed loading shelf 430 so that all of the orders that request aspirin can be filed in one pass. Once the aspirin has been distributed, the operator hits pushbutton 370 which informs the controller that he is finished with the designated tasks. The platform would then be rotated to present the next stock unit which would be distributed in the same manner. After all of the orders that are to be filled with items contained within container No. 123 have been distributed, it would be discharged from the work table and returned by the takeaway system 16 and an external conveyor network to the storage structure or other appropriate station. While the contents of the first container are being distributed, additional containers are delivered to the remaining work tables. The contents of a second container located on a table adjacent the first are then distributed in the same manner. This cycle is continued using all of the work tables, with new containers being delivered to each table after the container located thereon has been dis- charged. When the last item to be placed in each of the totes is delivered, the printer 435 is activated to print a shipping invoice or receipt when the tote drawer is first opened. As previously indicated, the printer is mounted on a carriage that travels back and forth across the front face of the consolidation queue. Therefore, the operator may readily grab the shipping invoice and place it in the open tote along with the final goods. It will be appreciated that with such a system a very large number of orders can be filled with a minimum number of operator man-hours. Most importantly, a single operator working at a single work station can consolidate entire orders and entire batches of orders. It should be appreciated that the controller may be designed to provide inventory control as well. Specifical- ly, when goods are received into the system, the controller is informed of the number of goods placed into the con¬ tainer. As distribution occurs, the controller instructs the operators to issue specific quantities of goods. Therefor, the controller can subtract the number of goods distributed from the number of goods originally stored in the container. When a particular container compartment is supposed to be empty, the controller would so inform the operator on the video terminal 50. Since the video terminal would typically be a monitor for the computer that functions as the work center controller, a keyboard would generally be provided in the work area 5 so that the operator can manually inform the controller of ' inventory shortages and excesses. It has been determined that for most high volume operations, approximately four work tables are desirable to ensure that the operator will virtually always have some¬ thing to distribute. However, the actual number may vary dependant upon the requirements of a particular system. It should be appreciated that on any given day, the actual number of orders that request a particular stock unit will vary greatly. To ensure a smooth operation, it is desirable to regulate the delivery of the containers to the work tables to provide balance. Thus, rather than filling all of the work tables with containers carrying stock units that are only requested in one or two orders each, the control system is preferably designed to deliver some containers that carry goods that are requested by a relatively large number of orders simultaneously with those carrying items requested in only a few orders. Such balance reduces the likelihood that the operator will fill the orders faster than the system can provide new containers. It should also be appreciated that the actual sequence in which the various products are distributed may be widely varied within the scope of the present invention. The actual distribution sequence will most likely be the product of an optimization routine tailored to a specific applica¬ tion. Thus, in our example, suppose that one and only one of the orders calls for a toothbrush. When the shelf carrying the tote associated with the order for a toothbrush is positioned adjacent the fixed loading shelf 430 of consolidation queue 18, it may be desirable to distribute the toothbrush at that time, rather than waiting for all of the aspirin orders to be filled and having to rotate the consolidation queue back to the proper shelf. The video terminal 50 and the appropriate video display 52 would display suitable instructions to the operator. It should be apparent that the instructions of video terminal 50 and display 52 may be presented in a wide variety of ways and a ey can rea y e n egra e n o a s ng e sp ay unit. The temporary storage queue 9 (preferably in the form of vertical queue 11) is provided to ensure that working containers will always be available to the work tables. Thus, the system is. able to request containers from the storage structure well in advance of the time they are actually required to eliminate delays while the containers are being retrieved from storage. Similarly, each work table 7 is provided with a loading ramp 20 that is capable of holding a. container in a position free of interference with the delivery of containers to the other work tables. Thus, the system controller is preferably designed to request the delivery of a container to the loading ramp associated with a particular work table before the container held thereon is discharged, thereby further reducing the down time between discharging a depleted container from the work table until the delivery of a new one. Any time a con¬ tainer is discharged from the work center, the controller orders a new container to replace it. When the new con¬ tainer arrives at the work center, an identification scanner reads the identifying indicia thereon and reports the containers identity to the system controller which is then free to select delivery of that particular container to one of the work tables at any time depending upon the needs of the system. The aforementioned process is repeated until all of the orders in the batch are filled. It will be appreciated that there is no need for the operator to know in advance the expected contents of each of the tote drawers. Rather, the controller may be designed to merely provide instruction as to how many of which items carried by a container on one of the work tables are to be placed in the open tote drawer. When the final items have been placed in the tote, the consolidated orders disposed in the tote drawers 19 are then ready for delivery to the customers. The tote drawers may be readily removed from the consolidation queue for delivery to the final destina- tion. If the customer is an internal production facility, the totes may be delivered to the production work stations. If the orders are to be delivered by mail or parcel post, the totes would be delivered to a packing or wrapping station. If the goods are to be delivered to the customers by truck in the totes, the totes may be delivered to a shipping queue as previously discussed that arranges the totes in reverse delivery order to facilitate loading onto a delivery truck. Although the totes could be readily arranged for shipping by selecting the order of the removal from the consolidation queue, in high volume operations, such a procedure would take too much time and therefore a separate shipping queue may be provided to coordinate the outgoing freight shipments. RECEIVING WORK STATION The work center may also be configured specifically to receive inventory into the system. Referring next to Figure 40, an embodiment of the receiving work station 601 chosen for the purpose of illustration includes a work area 5 having a plurality of rotating work tables 7, a temporary storage queue 11, a supply conveyor 12, delivery system 14, takeaway system 16, a receiving transport conveyor 605, a cubing table 607 and storage shelves 618. In an alternative embodiment storage shelves 618 may be replaced by a con- solidation queue 18. Additionally, it may be desirable to provide the receiving transport conveyor 605 with a tempo¬ rary storage queue for holding received packages until an operator is ready to work with them. The receiving station functions quite simply. Specifi- cally, goods brought into the distribution facility or warehouse are placed onto receiving transport conveyor 605. The receiving transport conveyor carries the received goods to the receiving work station 600. The receiving transport conveyor 605 is adapted to carry a typical assortment of packages of material of the type to be stored within the storage facility in containers 13. Of course, the actual shape and sizes of the received packages can take on a wide . , , most, of the received goods will have appropriate bar coded labels when they are received into the facility. In such systems, when an operator receives a package, a hand held bar code scanner 439 located adjacent the receiving trans¬ port conveyor 605 may be used to automatically identify the received goods. The operator would then only need to verify that the scanner recorded both the proper identity and quantity of the received goods. The receiving station also includes a video terminal 50 which displays the read information. The terminal may be the monitor for the work center controller 500 which may take the form of a personal computer or any other suitable computer terminal. Thus, if the scanner is unable to identify the received goods, or if the goods are damaged or otherwise nonconforming, then the operator may manually input the correct information. Once the work center controller is informed about the nature of the goods received, it determines the container compartment size appropriate for holding the received goods. As described above, it is contemplated that many of the containers 25 will have multiple compartments 27 and that any particular container having multiple compartments would have a variety of different goods stored within its various compartments. To optimize space utilization within a warehousing system, it is desirable to have each of the containers as full as possible. Thus, the controller must calculate the expected volume of the received goods and coordinate the delivery of a container having an empty compartment large enough to hold those goods. It should be appreciated that to optimize space utilization it is desirable to place the received goods in the smallest practical compartment. A cubing table 607 is provided to calculate the size and weight of goods inputted into the system. Once the size and weight of a particular item has been determined, the system controller records the measured physical character¬ istics of the item. Therefore, any time similar goods are received in the future, the controller can calculate the appropriate compartment size for any given quantity re¬ ceived. The cubing table 607 may take the form of a flat table that rests upon a scale and has sensors to measure the maximum length, width and height of the received goods. When an entirely new item is received, the item is placed on the cubing table and. its measurements are taken. The operator than informs the controller of its measurements and the controller calculates the volume required for each item and multiplies the calculated volume by a fudge factor which insures that the ^ operator will not have to spend an inordi¬ nate amount of time stacking the item into a compartment. The controller then records the adjusted volume per unit in a weights and measurements file for future reference. After the proper container size has been determined, a container is ordered that has a suitably sized empty compartment.. It should be appreciated that the master controller 501 would generally maintain an inventory record that records the identity and quantity of items stored in each container. The master controller 501 also maintains a listing of which compartments are empty and their designated size. Therefore, when a request is made for a container having a particular sized compartment, the master controller can provide an extended list of available containers that have an appropriately sized empty compartment. Contrary to what might be the intuitive approach, it is desirable to refill a container well before it is completely emptied in order to maximize space utilization. Therefore, containers are generally brought into the receiving station partially full, with some of their compartments empty. After the goods have been received and the appropriate compartment size calculated, a container having a suitably sized empty compartment is delivered from the vertical queue 11 to one of the work tables 7 in the receiving work station 1. When an appropriate container is delivered to a work table, the signal light 375 associated with that container is lit to inform the operator which table is active and the video terminal 50 would inform the operator of the appro¬ priate compartment into which the received goods should be 5 placed. The operator then places the received goods into the selected container compartment. Once the operator is finished loading the received goods into their designated container, he hits a pushbutton 370 ' which informs the controller that loading is complete. If the particular 10 container used is completely filled, then it will automati¬ cally be discharged from the work table and delivered via takeaway system 14 and conveyor network 24 to storage 2 or another appropriate work station. If the container has additional empty compartments, it may be retained on the 15 work table to receive the next items that require that particular compartment size. The controller is designed to request the delivery of containers having appropriate empty compartments before they are needed. The containers delivered are stored in the 20. vertical queue 11 until they are needed on one of the work tables. Since different containers will have different compartment sizes, the controller will attempt to stock the vertical queue with a variety of containers which having different compartment sizes. Generally, the number of 25 containers in the queue having a particular empty compart¬ ment size will depend on the anticipated demand for that particular container size. Storage shelves 618 are provided in the vicinity of the work area to hold items that can not immediately be placed 0 into containers. It will be appreciated that occasionally, there may be time delays in delivering appropriately sized containers to one of the work tables. In such cases, the controller realizes that it does not presently have a suitably sized container on one of the work table and it 5 instructs the operator to place the received goods on a particular one of the storage shelves 618. At a later time, when an appropriately sized container is delivered to the work station, the controller instructs the operator to retrieve the stored item from shelves 618 and place the items in the appropriate container. In some high volume operations, in order to maximize efficiency, it may be desirable to provide temporary storage for substantially all of the received goods before they are loaded into containers in order to separate the receiving and replenishment functions. To accommodate this, a con¬ solidation queue 18 would be provided in place of storage shelves 618. In such a system, the operator would scan or otherwise inform the controller of the identity of the received goods as previously described. The controller would then cause the consolidation queue to open one of the to.te drawers 19 (or more if necessary) . The operator would then place the received goods in the open tote drawer 19 and the controller would remember where the particular goods are stored. After all of the goods have been received, the controller would then coordinate the delivery of containers to the work table and the opening of the tote drawers to facilitate replenishing the inventory. Specifically, the controller coordinates the delivery of containers having empty compartments to the work area. Once an appropriate container is delivered to a work table, the signal light 375 disposed over the active work table 7 is lit to inform the operator of the active table. The controller opens a tote drawer holding items that require the designated compartment size and the operator transfers the goods between the open tote and the selected container. When the transfer is complete the operator pushes pushbutton 370 to inform the controller that the task is complete. This process is repeated until all of the received items have been entered into inventory. It will be appreciated that such an operation can allow a single operator to efficiently carry out the receiving function for a relatively large operation. When demand becomes to much for a single operator, addition¬ al receiving work stations can be provided. CONTROL SYSTEM It will be appreciated that a wide variety of automated controllers could be developed to drive the work center heretofore described. A good controller system must lend itself to a modular construction so that if and when the needs of the work center change, additional components may be added or subtracted with little or no change in the system software. To maximize efficiency, the system controllers should be arranged to ensure that an operator working at one of the work centers will always have work on hand as opposed to having to wait for a working container to arrive. Efficient integration of the system requires a tremendous amount of computing power capable of handling tens of thousands of requests per hour. By way of example, a control system suitable for substantially automatically directing a representative work station that includes a single work area 5 having four rotatable work tables, a vertical queue 11, and a consolida¬ tion queue 18, as well as the conveyor segments necessary to connect the various components as discussed above will be described. Referring initially to Figures 41 and 42, the control architecture includes a plurality of pyramided local area networks (LANs) intended to distribute responsi¬ bility towards the lowest level. The control system includes a master controller 501 that communicates with one or more work center controllers 500 over a primary local area network 509. Each work center 1 has an associated work center controller 500 that monitors its activities. Each work center controller coordinates the activities of a plurality of component controllers that each control the activities of one or more specific components. In the described embodiment, the component controllers include a queue controller 502, a consolidation controller 504, a table controller 506 and a local conveyor controller 508. AS best seen in Figure 42, each work center controller 500 communicates with its associated component controllers over a dedicated second tier local area network 510. Each of the various component controllers communicates with a plurality of programmable array logic boards 550 over a third tiered local area network 511. The logic (PAL) boards 550 in turn directly control the motors, rams and other mechanisms that drive the described components of the storage system. Additionally, the logic boards 550 receive information provided by presence scanners 23 and other components to determine whether a particular request made by the carousel controller can be safely carried out. The master controller 501 is responsible for knowing the contents within each container, receiving orders, and coordinating the activities of the various work center controllers as well as any external controllers. By way of example, an external computer can control the delivery of containers to the work center and/or the distribution of customer orders as described in co-pending Application Serial No. 158,310 filed February 22, 1988. Alternatively, the master controller may itself be responsible for such tasks. To keep track of the inventory within the system, the master controller 501 maintains an inventory file that keeps track of all of the goods in inventory, together with an indication of the container(s) and compartments within the containers in which specific goods are stored. In one of the preferred embodiments, the inventory record includes a listing of the contents in each compartment of each con- tainer. Thus, when it is necessary to locate empty con¬ tainers or those having empty compartments of a particular desired size, a listing of such containers can be readily ascertained by searching through the inventory record. The inventory record includes an indication of the container number and compartment in which particular goods are stored, the identity of the goods, the quantity of the goods, and the date the goods were received into inventory (to facili¬ tate FIFO inventory procedures) . The master controller also maintains a weights and measures file which remembers the weight and dimensions of all of the items expected to be in inventory. Thus when an item is received, the control system can look up its anticipate size and calculate the compartment size that is appropriate to hold the received goods. Anytime a new item is received by the system, its weight and dimensions are check and this new information is provided to the weights and measures file. When an order is received, it is entered into a customer order file in the master controller 501. The master controller then searches the inventory record to determine whether the ordered goods are in inventory and designates the particular container(s) that hold the desired goods. The orders are then divided into related batches as previously described and each of the work center controllers would be provided with a batch of orders which its associ- ated work center is expected to fill. By way of example, a batch of orders may include all of the orders for a particu¬ lar family of good. After a particular batch has been filled, a new batch of orders may be provided. This cycle would be continued until all of the orders have been filled. Alternatively, the batch of orders may include all orders expected for a particular day or work shift. It should be appreciated that the system can readily be modified to facilitate updating the batch of orders as new orders are received. Each batch of orders is arranged in the form of an issuing in process file. The issuing in process file contains all of the information that the work center will require in order to independently process the orders in its batch. Specifically, this includes identifying the specific orders to be processed, including the particular items and quantities that are requested in each order, billing information so that the shipping invoices may be printed, and an indication of specific containers (including compart¬ ment designations) which carry each of the ordered goods. At the beginning of any issuing procedure, the master controller 501 would transmit an issuing in process file to the work center controller 500 responsible for the particu- lar batch of orders. At the end of the issuing process, the work center controller would inform the master controller of the particular orders it was able to fill. Additionally information about inventory discrepancies in the containers may be provided as well. When a work center is being used as a receiving station, the master controller would initially provide the work center controller 500 with an extended list of con¬ tainers having empty compartments along with an indication of the size and location of the empty compartments within the listed containers. The work center controllers 500 are responsible for integrating and directing ' the activities of the component controllers within their designated work station and communicating with the master controller 501 and any other external controllers. The specific component controllers include queue controller 502, a table controller 506, local conveyor controller 508 and when appropriate, consolidation controller 504. The work center controller also directly controls communications with the operator via video terminal 50 and video displays 52. The queue controller 502 manages vertical queue 11. The consolidation controller 504 manages the consolidation queue 18 and its respective tote drawers 19. Specifically it organizes the rotation of the shelves, the insertion and removal of tote drawer 19 from the consolidation queue, and the opening of tote drawer 19 onto the fixed loading shelf 430. The consolidation controller also communicates with a plurality of sensors that are adapted to detect the closing of a particular drawer. The work table controller 506 manages the activities of the rotatable work tables 7 and the local conveyor controller 508 manages the activities of supply conveyor 12, delivery system 14 and takeaway system 16. The queue controller directs two logic boards 550 that take the form of queue PAL board 552 and queue safety PAL board 554. Queue PAL board 552 directs the operations and movements of loading ramp 20, motor 117, pneumatic shock absorbers 140,141 on the soft stop mechanisms 136, the strike rod that drops the shelf blockers 119, and power operated stopper 164. The queue safety PAL board monitors a plurality of sensors that insure that everything is clear for the- queue to rotate or otherwise perform a requested function. In particular, sensors verify that the soft stop mechanisms 136 are fully retracted, that nothing is obstructing the junction between loading ramp 20 and the vertical queue and that power operated stopper 164 has been returned to its blocking position. The queue PAL board 552 will not perform a requested function until it receives an enable signal from the safety PAL board 554. The table controller 506 directs four logic boards each of which controls the activities of a single work table. Specifically, each table PAL board 556 runs the reversible motors 336 that lift and lower the front and back sides of the work table base 310, as well as drive motor 312 which rotates the platform 309. In addition, the table PAL boards monitor the safety sensors and conveyor conditions to insure that the table is free to preform its requested functions. The conveyor controller 508 watches over three logic boards including supply PAL board 558, delivery PAL board 560 and takeaway PAL board 562. Supply board 558 controls the activities of supply conveyor 12 and transfer stop 90. Delivery board 560 controls delivery system 560 and transfer stops 190, while takeaway PAL board 562 controls the takeaway conveyor system. The consolidation controller 508 directs several logic boards including a consolidation PAL board 564 and safety PAL board 566 which control the rotation of the consolida¬ tion queue and monitor that it is clear to rotate in a manner similar to the way queue PAL board 552 and queue safety PAL board 554 operate. A printer PAL board orches- trates the movements of the printer and separate ram PAL boards are provided to direct the operation of each set of pneumatic rams 431, etc. Communications between the various component con¬ trollers and their respective logic boards 550, may be accomplished through the use of a wide variety of conven¬ tional communication networks. However, in order to reduce the total computing power required, as well as to reduce costs and maximize efficiency, a novel LAN architecture has been developed to facilitate such communications. One of the overriding goals of the described archi¬ tecture is to minimize or even eliminate the need for priority interrupts. It has been our experience that with the volume of data that must be transferred between the logic boards and the component controllers, an architecture based upon priority interrupts is needlessly complicated and inefficient. Therefore, referring specifically to Figure 42, a plurality of interface boards 570 are provided to act as buffers for communications between the logic boards and the component controllers. The interface boards are formed of 8-bit I/O registers, that temporarily store received data. In effect each of the logic boards may send messages to the appropriate component controller over its associated third tier LAN 511 at any time. The messages are received by an interface board associated with the particular logic board and saved in a temporary buffer. Therefore, the component controllers can go about their business in an orderly fashion without having to deal with interrupts from the logic boards. As the component controllers perform their designated tasks, they periodically check their associated interface boards to determine whether the logic boards have sent any messages since the last inquiry. By way of example, the master controller 501 and work center controller may take the form of conventional personal computers such as the IBM AT. The component controllers may take the form of compatible microprocessors having internal memory such as INTEL 8032's or 8052's. The interface boards may take the form of 8-bit I/O registers and the logic boards may be formed of programmable array logic chips such as the 20L8. When a container is received by the work center it approaches on supply conveyor array 12. An identification scanner 22 disposed adjacent the supply conveyor acknow¬ ledges the reception of a particular container (i,.e, #123) and informs the conveyor controller 508 of its arrival. The conveyor controller then informs both the queue controller .1 502 and the work center controller 500 of the arrival of container #123. The work center controller 500 responds by instructing the conveyor controller to deliver the container to a particular loading ramp 20. The conveyor controller then instructs the supply PAL board 558 to actuate the appropriate motors and alignment stops to deliver container #123 through the appropriate transfer stop 90 to the selected loading ramp 20. Presence sensors SI disposed adjacent the loading ramps 20 detects the presence of a container on the loading ramp and presence sensors S2 disposed adjacent the transfer stops 90 detect the presence of containers on the transfer stops. Both of these presence sensors are monitored by the supply PAL board. If a container is located in a transfer stop or on a loading ramp through which container #123 is supposed to pass, the supply board will not carry out the requested transfer and will inform the conveyor controller of the blockage. When the blocking container is removed (as detected by sensors S1,S2) the supply PAL so informs the conveyor controller which then issues another command to advance the container towards its loading ramp 20. Presence sensor SI is monitored by both queue PAL board 552 and supply PAL board 558. Therefore, when the container is positioned on the loading ramp 20 both the queue controller and the conveyor controller are so informed. The conveyor controller informs both the work center controller and the queue controller that container #123 is now resting in loading ramp 20. The queue con¬ troller then proceeds to insert the container onto an empty shelf when it gets a chance. When the queue controller is ready to insert container #123 onto the vertical queue, it instructs the queue PAL board 552 to activate drive motor 312 to rotate the compres¬ sion chain until an empty shelf is disposed adjacent the loading ramp 20 holding container #123. The queue con¬ troller 502 remembers which shelves carry containers, as well as the identity of the particular containers stored on each. In the gravity motivated loading ramp previously described, the transfer between the loading ramp 20 and the vertical queue 11 is accomplished by releasing power stopper 164. When an empty shelf 111 is positioned adjacent the loading ramp, queue controller 502 instructs queue PAL board 552 to extend soft stop mechanism 136 and release the power stopper 164. A presence sensor S3 that is monitored by safety PAL board 554 verifies that the shelf is indeed empty. Assuming that all other safety checks are clear, the safety PAL board issues an enable signal to the queue board and loading is carried out as previously described. Once container #123 is properly positioned on the shelf, the queue controller waits for further requests from the work center controller or the delivery of other containers to the loading ramps. Before the queue can be rotated again, the queue safety PAL board 554 must verify that everything is clear. When an operator is ready to begin filling orders, the work center controller 500 provides the queue controller 502 with a list of desired containers known to be in the vertical queue. The queue controller then chooses the listed container that is easiest to provide (typically the container closest to the delivery system 14) and causes the vertical queue to rotate until the selected container is adjacent the delivery system, wherein the queue is momen¬ tarily stopped and the appropriate shelf blocker 119 is released allowing the selected container to roll on the delivery system 14. Once the queue controller chooses the container(s) to be delivered, it informs the work center controller 500 of its choice (container #123 in the ex- ample) . The work center controller then instructs the local conveyor controller 508 to deliver the container to a particular work table 7. The local conveyor controller 508 then manages delivery of the container ' to the loading ramp 20 associated with the chosen work table. The actual mechanics of movements along the delivery system are similar to those described for the supply conveyor and are directed by delivery PAL 560. An identification scanner 22 disposed adjacent the delivery conveyor verifies the identity of the container being delivered to the work tables and observes its orientation. The work center controller and the table controller are both informed when container #123 is actually delivered to the work table loading ramp by a presence sensor S4 positioned to monitor the loading ramp. At this point, the table controller takes responsi¬ bility for the container. As soon as the work table itself is emptied, the platform is raised and tilted into a position for receiving the container. The individual table PAL boards monitor presence sensor S4 and presence sensors S5 which detect the presence of a container on the platform 309. Any time the table PAL notices a container on the loading ramp and the absence of a container on platform 309, it directs reversible motors 336 to lift the platform to the level of the loading ramp and put in the appropriate tilt. Other presence sensors (not shown) are used to monitor the height of the platform. The table controller 506 then orchestrates the transfer of the container from loading ramp 260 to the rotating work table 7. This includes dropping power operated stopper 164 and gate 321. Once the gates have been dropped the container flows onto the work table. Sensor S5 indicates to the table PAL board when the con¬ tainer is properly positioned and gates 164 and 321 are raised to their default positions. - Once the container is loaded, the table PAL informs the work table controller which then instructs the table PAL to lower the table to a particular position (associated with the operators height) and rotate the platform so that the appropriate compartment faces the operator. Once that movement is completed, the table PAL so informs the table controller which in turn informs the work center controller. Once the container is disposed on the work table, the work center controller decides how the goods contained therein will be distributed. Using the aspirin example, the work center controller informs the consolidation controller 504 of specific shelves and tote drawers to be opened and the sequence in which they should be opened. Simultane¬ ously, the signal light 375 associated with the work table " that holds the selected container is lit and the video terminal 50 and the video displays 52 associated with the open tote draw present instructions telling the operator the identity and quantity of the next items to be picked. By way of example, the video terminal may indicate the identity of the next few stock items to be distributed, the table on which the container holding the goods is located, the compartment within the container holding the goods and the total number of stock units to be distributed. Each of the video displays 52, which are disposed on the consolidation queue above the tote drawers may display the number of stock units to be placed in their associated tote drawers to¬ gether with a short description of the stock unit (i.e., Bottles of Bayer aspirin - 5 mg - 100 tablets) . After receiving instructions from the work center controller, the consolidation controller 504 instructs consolidation PAL 564 to activate the drive motor to rotate the consolidation queue until the desired shelf is adjacent the fixed loading shelf 430. Of course, consolidation PAL 564 can not rotate the queue unless it receives an enable signal from safety PAL board 566. Once the proper shelf is in position, the consolidation controller is informed of the successful rotation and instructs the ram PAL board to actuate the appropriate ram thereby causing the first selected tote drawer to open and the operator places the required number of units therein (as indicated by video display 52) . When finished, the operator manually closes the tote drawer. The closing event is detected by a sensor (not shown) which informs the consolidation PAL board 564 which in turn informs controller 504 that a task has been completed. The consolidation controller then directs the ram PAL to open the next drawer and informs the work center controller of the closing event. The work center controller updates the video terminal and displays to eliminate the finished order. Preferably, the video terminal would always display the next several picks so that during a single trip to the work table, the operator can grab enough stock units to fill several orders when appropriate. It will be appreciated that the work center controller 500 need only inform the consolidation controller of the identity and sequence of the drawers to be opened. Prefer¬ ably only the next few drawers to be opened would be disclosed at any one time, with the list being periodically updated. It should also be appreciated that the work center con¬ troller 500 knows how many more drawers are to be filled with aspirin, as well as how many units of aspirin are expected to be in the active container. Thus, if all of the active aspirin orders have been filled, or if the entire supply of aspirin is depleted, the work center controller would determine whether there are any other products to be distributed from the active container. If so, those products would be distributed in the described manner. If not, the table controller 506 would be directed to discharge the aspirin container #123 to the takeaway system 16 which returns the container to the conveyor network 24. If the container holds two material items that are to be distri- buted, it may be necessary to rotate the container after the first item has been picked. This is accomplished simply by having the work center controller direct the table con¬ troller to rotate the container the desired amount. The described cycle is repeated until all of the orders have been filled. In some cases it may be desirable to have the operator interrupt distributing goods disposed in a container located on one work table to distribute goods from another container. This is particularly true if the second container has only a few goods to be distributed. Since several totes are arranged in parallel on a single shelf, when the consolidation queue is rotated such that the tote designated to receive items from a second or third container are positioned adjacent the fixed loading shelf 430, then the work center controller may be programmed to direct the consolidation controller to open the tote drawer associated with goods from the second container. The operator is then informed of the switch by video terminal 50. Since the consolidation controller is only instructed to open particu¬ lar totes drawers, it does not need to be specifically informed of the switch. When the final item is placed in a particular tote to fill a single order, the work center controller instructs the consolidation controller 504, which in turn directs the printer PAL 569 to position the printer 435 over the open tote. The printer PAL 569 remembers each printer position and needs only be instructed of the position to which it must travel. The work center controller may simultaneously activate the printer using standard printer interface routines. The general control architecture for a receiving work station will be very similar to the controller described for the issue work station. Since the receiving station includes a vertical queue, a plurality of work tables and various conveyor arrays it would have the described table, queue and conveyor controllers. The receiving work center controller would also monitor bar code scanner 439 which is used to identify received goods. If the received goods have appropriate bar code labels indicating both the identity and quantity of the goods, the receiving work center controller calculates the container size necessary to hold the received goods and directs the queue controller to deliver an appropriate container to one of the work tables in the manner previously described. The operator then places the received goods into the container and strikes the pushbutton 370 which notifies the work center controller that the task is completed. Although only a few embodiments of the present inven- tion have been described in detail, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. It will be apparent that each of the describe componants could be varied to a large degree. Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.

Claims: WHAT IS CLAIMED: 1. An automated work station for use in materials handling operations including a conveyor network for carrying containers, said work station comprising: a randomly accessible vertically moving storage queue having a multiplicity of vertically spaced shelves arranged about an endless loop, said shelves being adapted for holding said containers; loading means for receiving containers from said conveyor network and for loading the received containers onto shelves of said storage queue; a plurality of work tables for providing an operator access to the containers to selectively add or withdraw articles from said containers; delivery means for - transferring selected containers from said storage queue to said work tables; takeaway means for transferring containers from said work tables to said conveyor network; and control means for automatically controlling the delivery of containers between said vertical queue and said work tables. 2. An automated work station as recited in Claim 1 wherein said control means includes: an electrical communication network having electrical circuits that direct specific movement of said storage queue, said loading means, said work tables, said delivery means and said takeaway means; and computer means connected to the communication network for generating communication signals according to a pre- determined program, the communication signals directing the electrical circuits to direct specific tasks. 3. An automated work station as recited in Claim 2 wherein said loading means includes a gravity motivated loading ramp for transferring containers between said supply conveyor and said storage queue. 4. An automated work station as recited in Claim 3 wherein said loading ramp includes a receiving end disposed adjacent said supply conveyor for receiving containers from the supply conveyor and a discharge end disposed adjacent said endless loop for loading containers onto said shelves, said discharge end being lower than said receiving end, a plurality of rollers for supporting said containers on the loading ramp, and a power operated blocker for selectively retaining containers on said loading ramp, said power operated blocker having a first operable position that retains said containers on the loading ramp and a second operable position wherein said containers are free to pass over the power operated blocker. 5. An automated work station as recited in Claim 4 wherein said loading ramp further includes a plurality of power actuated rollers. 6. An automated work station for use in materials handling operations making use of a multiplicity of totes and containers for receiving articles and a conveyor network for carrying said containers, said work station comprising: a randomly accessible temporary storage queue having a multiplicity of shelves for receiving said containers; a work area for providing an operator access to the containers to selectively add or withdraw articles from said containers; delivery means for transferring selected containers from said storage queue to said work area; takeaway means for transferring containers from said work area to said conveyor network; a rotational consolidation queue having a multiplicity of shelves disposed about an endless loop for receiving said totes, said consolidation queue being disposed in close proximity to the work area so that an operator may readily transfer articles between the work area and the consolida- tion queue, said consolidation queue including a loading shelf for providing the operator access to the totes and opening means for transferring said totes from said consoli¬ dation shelves to said loading shelf; and control means for automatically integrating the delivery of containers from the temporary storage queue to the work area with the rotations of the consolidation queue and transferring the totes from the shelves of the con¬ solidation queue onto the fixed loading shelf to facilitate transferring articles between the containers and the totes. 7. An automated work station as recited in Claim 6 wherein said work area includes a plurality of work tables. 8. An automated work station as recited in Claim 7 wherein said work tables are rotatable such that they may present the containers to the operator in any orientation. 9. An automated work station as recited in Claim 7 wherein said temporary storage queue is a rotational vertical queue and said shelves are carried about a vertically traveling endless loop. 10. A randomly accessible vertically moving storage queue for receiving containers from a loading ramp and randomly discharging the received containers onto conveyor means, the vertical storage queue comprising: a frame; queue track means carried by the frame and forming a vertically oriented endless loop having an up travel reach and a down travel reach; a multiplicity of vertically spaced shelves carried by the queue track means, each said shelf being pivotally coupled to said queue track means such that the shelves remain substantially horizontal as they are carried between the up travel reach and the down travel reach; drive means for rotating the shelves about the endless loop; loading means for transferring containers from said loading ramp onto said shelves; and unloading means for transferring containers from selected shelves to said conveyor means; whereby to load the vertical storage queue, the shelves are rotated until an empty shelf is disposed adjacent the loading ramp and the loading means is activated to load a particular container onto the empty shelf, and whereby to unload a selected container from the vertical storage queue, the shelves are rotated until the shelf carrying the selected container is disposed adjacent the conveyor means and the unloading means is activated to remove the selected container from the vertical storage queue. 11. A vertical storage queue as recited in Claim 10 wherein said queue track means includes a compression chain com¬ prised of a multiplicity of pivotally coupled linkage bars and a multiplicity of axles for pivotally coupling adjacent linkage bars. 12. A vertical storage queue as recited in Claim 11 wherein: said queue track means further comprises a multiplicity of brackets, wherein a first end of each said a bracket is mounted to a particular one of said axles and the second end of each said bracket is secured to an adjacent bracket at a position that is spaced apart from said compression chain to form a pivot point; and each said shelf includes a pair of suspension struts that are pivotally coupled to a particular one of said pivot points. 13. A vertical storage queue as recited in Claim 12 wherein said queue track means includes a pair of identically sized facing compression chains that each carry an identical number of brackets and each said shelf includes two pairs of suspension struts wherein a first one of the suspension strut pairs is pivotally coupled to a first compression chain and the second suspension strut pair is pivotally coupled to the opposite compression chain. 14. A vertical storage queue as recited Claim 13 further comprising guide means for insuring that the shelves remain substantially horizontal as they pass between the up travel reach and the down travel reach of the endless loop. 5 15. A vertical storage queue as recited in Claim 14 wherein said guide means includes a guide channel mounted on said frame and wherein each said shelf further includes a guide tube extending outwardly from the shelf for engaging the guide channel as the shelf travels between the up travel 10 reach and the down travel reach of the endless loop. 16. A vertical storage queue as recited in Claim 10 wherein each said shelf includes a power operated gate for retaining containers on the shelf. 17. In a materials handling operations that makes use of a 2-5 work station having a work area for providing an operator with access to containers adapted to carry various articles, a supply conveyor for delivering containers from an external storage system to the work station, and delivery means for delivering the received containers to said work area, the Z0 improvement comprising a randomly accessible vertically moving storage queue including: a frame; queue track means carried by the frame and forming a vertically oriented endless loop having an up travel reach 25 and a down travel reach; a multiplicity of vertically spaced shelves carried by the queue track means, each said shelve being adapted to carry at least one of said containers, said shelves being pivotally coupled to said queue track means such that the 30 shelves remain substantially horizontal as they are carried between the up travel reach to the down travel reach; unloading means for transferring selected containers from said shelves to said delivery means; means for rotating said shelves about the queue track 35 means; and supply conveyor onto said shelves, said loading ramp including a selectably actuatable discharge means for holding said containers on the loading ramp in a position free from interference with the rotation of the shelves until the vertical storage queue is prepared to receive a new container and for selectively discharging the containers from said loading ramp onto a particular one of said shelves that is disposed adjacent the loading ramp; whereby to load the vertical storage queue, the shelves are rotated until an empty shelf is disposed adjacent the loading ramp and then the discharge means is activated to load a particular container onto the empty shelf, and whereby to unload a selected container from the vertical storage queue, the shelves are rotated until the shelf carrying the selected container is disposed adjacent the delivery means and the unloading means is activated to remove the selected container from the vertical storage queue. 18. An automated work station as recited in Claim 17 wherein: said loading ramp includes a receiving end disposed adjacent said supply conveyor for receiving containers from the supply conveyor, a discharge end for loading containers onto said shelves, and a plurality of rollers for supporting said containers on the loading ramp; and said discharge means includes a power operated blocker disposed on said loading ramp for selectively retaining containers thereon, said power operated blocker having a first operable position that retains said containers on the loading ramp and a second operable position wherein said containers are free to pass over the power operated blocker. 19. An automated work station as recited in Claim 18 wherein said discharge end of the loading ramp is lower than said receiving end of the loading ramp so that the loading ramp is gravity motivated. 20. An automated work station as recited in Claim 18 wherein said rollers are power actuated. 21. An automated work station as recited in Claim 17 wherein each said shelf includes a gate for positioning said containers on the shelf, said storage queue further com¬ prises a soft stop means for absorbing a substantial portion of the momentum of the containers as they are loaded onto the shelf adjacent the loading ramp before the container strikes said gate. 22. An automated work station as recited in Claim 21 wherein said soft stop means includes a strike bar pivotably coupled to the frame and a shock absorber for absorbing a substantial portion of the momentum of the containers as they are loaded onto the shelf adjacent the loading ramp before the container strikes said gate. 23. A randomly accessible consolidation queue for present¬ ing article containing totes used in material handling operations to an operator, the consolidation queue compris¬ ing: a frame; a loading shelf for providing the operator access to the totes; queue track means carried by the frame and forming a vertically oriented endless loop having an up travel reach and a down travel reach; a multiplicity of vertically spaced shelf pans carried by the queue track means for holding said totes, said shelf pans being pivotally coupled to said queue track means such that they - remain substantially horizontal as they are carried between the up travel reach and the down travel reach, each said shelf pan including a multiplicity of tote pads each adapted to hold one of said totes; drive means for rotating the shelf pans about the endless loop; opening means for transferring totes from the tote pads on an active shelf pan positioned adjacent said loading shelf onto the loading shelf to facilitate inserting articles into and removing articles from the totes; and control means for automatically directing the drive means to rotate the shelf pans and actuating said opening means to transferring selected totes carried by the con¬ solidation queue onto the loading shelf. 24. A consolidation queue, as recited in Claim 23 wherein said opening means includes a first set of selectively actuatable rams disposed interior of the consolidation queue between said up travel reach and said down travel reach for pushing the selected totes from the active shelf pan onto said loading shelf. 25. A consolidation queue as recited in Claim 24 wherein said rams are pneumatic. 26. A consolidation queue as recited in Claim 25 wherein said rams are multi-stage. ' 27. A consolidation queue as recited in Claim 23 further comprising display means for communicating with the oper¬ ator, wherein the display means transmits instructions to the operator as to the identity and the quantity of the articles to be transferred between the totes disposed on the loading shelf and an external location. 28. A consolidation queue as recited in Claim 27 wherein the tote pads on adjacent shelf pans are vertically aligned and said loading shelf has a multiplicity of tote accom¬ modating positions that have the same spacing as the vertically aligned tote pads. 29. A consolidation queue as recited in Claim 28 further comprising a front panel mounted to the front side of the frame, the frame and front panel combining to form an opening suitable for passing totes between said active shelf pan and said loading shelf. 30. A consolidation queue as recited in Claim 29 wherein said display means includes a multiplicity of video dis¬ plays, each said video display being associated with a particular tote accommodating position and disposed on said frame above said frame opening. 31. A consolidation queue as recited in Claim 28 further comprising a printer for typing information about materials placed into or taken from said totes. 32. A consolidation queue as recited in Claim 31 further comprising: an elongated track mounted to the front side of the frame above said loading shelf; and a carriage for carrying said printer and coupled to said track for travel back and forth along the track to facilitate positioning the printer above any one of said tote accommodating positions. 33. A consolidation queue as recited in Claim 32 further comprising a bar code scanner carried by said carriage for inputting information into said control means. 34. A consolidation queue as recited in Claim 23 further comprising means for automatically loading totes onto said consolidation queue. 35. A randomly accessible vertically moving storage queue for temporarily holding containers and automatically discharging selected containers upon receiving instructions from a control system, the vertical storage queue compris¬ ing: a frame; queue track means carried by the frame and forming a vertically oriented endless loop having an up travel reach and a down travel reach; a multiplicity of vertically spaced shelf pans carried by the queue track means, each said shelf pan being pivotal¬ ly coupled to said queue track means such that the shelf pans remain substantially horizontal as they are carried between the up travel reach and the down travel reach; drive means for rotating the shelf pans about the endless loop; loading means for automatically transferring containers onto said shelf pans; and unloading means for automatically removing selected containers from the storage queue; whereby to load the storage queue, the shelf pans are rotated until an empty shelf pan is disposed adjacent the loading means and the loading means is activated to load a particular container onto the empty shelf, and whereby to unload a selected container from the storage queue, the shelf pans are rotated until the shelf pan carrying the selected container is disposed adjacent the unloading means and the unloading means is activated to remove the selected container from the storage queue. 36. A control system for an automated material handling work station, the control system directing a work station that includes a randomly accessible temporary storage queue for holding containers, ' a work area for providing an operator with access to .the containers, delivery means for transferring containers between said temporary storage queue and said work area, and takeaway means for transferring containers from said work area to an external location, the control system comprising: a queue control means for directing movements of the temporary storage queue; a conveyor control means for directing movements of the delivery and takeaway means; a work center control means for managing the activities of the queue control means and the conveyor control means and for coordinating communicating with the operator; a primary local area communications network that facilitates communication between the work center control means, the queue control means and the conveyor control means. 37. A control system as recited in Claim 36 wherein said work area includes a plurality of work tables and said control system further comprises a table control means for directing the movements of the work tables, said table control means communicating with said work center control means over said primary local area communication network. 38. A control system as recited • in Claim 37 wherein said work tables are rotatable to facilitate presenting the containers to the operator in multiple orientations, and the table control means directs the rotation of the work tables, the control system further comprising an identification scanner for identifying containers delivered to the work station and determining their orientation. 39. A control system as recited in Claim 36 further comprising a consolidation control means for managing the activities of a rotational consolidation queue adapted to receive a multiplicity of article containing totes and individually open said totes to allow the operator access thereto, said consolidation control means communicating with said work center control means over said primary local area communications network. 40. A control system as recited in Claim 39 wherein said work center control means instructs the consolidation control means to open selected totes and the consolidation control means coordinates rotations of the consolidation queue and the opening of the selected totes without any further instructions from the work center control means. 41. A control system as recited in Claim 39 wherein said work area includes a plurality of work tables and said control system further comprises a table control means for directing the movements of the work tables, said table control means communicating with said work center control means over said primary local area communications network. . con ro s s em as rec e n a m w ere n sa work center control means maintains an inventory file that records the location of each of the containers within the work station, and the identity of the contents stored within each container. 43. A control system as recited in Claim 36 wherein the work station further includes a supply conveyor for deliver¬ ing containers to the temporary storage queue and a loading ramp for loading containers onto the temporary storage queue, wherein''when a container is delivered to the loading ramp, the queue control means detects its presence and automatically proceeds to load the received container onto the temporary storage queue without receiving any instruc¬ tions from the work center control means. 44. A control system as recited in Claim 43 wherein when a container is discharged by the work area, the work center control means creates a container request list that indi¬ cates a plurality of containers located in the temporary storage queue that may be delivered to the work area and transmits the container request list to the queue control means, and the queue control means selects a particular container from the container request list and causes the selected container to be extracted from the temporary storage queue onto the delivery means for transportation to the work area. 45. A control system as recited in Claim 41 further comprising display means directed by the work center control means for communicating with the operator, wherein the display means includes a video monitor that displays instructions to the operator. 46. A control system as recited in Claim 45 wherein said display means further includes a plurality of signal lights, each said signal light being associated with a particular work table for indicating the active work table to the operator. 47. A control system as recited in Claim 45 wherein said display means further includes a plurality of pushbuttons, each said pushbutton being associated with a particular work table and actuatable by the operator to indicate that the operator is finished with the container disposed on the associated work table. 48. A control system as recited in Claim 45 wherein said display means further comprises a plurality of video displays, each said video display being associated with a tote accommodating position on the consolidation queue, and wherein the video display associated with a particular tote accommodating position that holds an open tote displays instructions to the operator. 49. A control system for an automated materials handling - work station comprising: a plurality of component controllers that manage the mechanical activities of particular functioning work station components; a work center controller for managing the activities of the component controllers and coordinating communications with an operator, the work center controller communicating with the component controllers over a primary local area network; a multiplicity of logic boards for directly controlling the mechanical functions of the work station components, each said component controller having a plurality of associated logic boards for directly controlling the mechanical functions of the particular component controlled by the associated component controller, each said component controller having an associated secondary local area communications network for communicating with its associated logic boards. 50. A control system as recited in Claim 49 further comprising a plurality ' of interface boards, each said interface board being associated with a particular component controller and having a plurality of buffers for receiving communications from said logic boards ' and serving to temporarily storing the information transmitted by the logic boards until the component controller signals a request for such information. 51. A control system as recited in Claim 50 wherein the controlled work station includes a temporary storage queue for holding containers, a work area for providing an operator with access to the containers, delivery means for transferring containers between said temporary storage queue and said work area, and takeaway means for transferring containers from said work area to an external location, and wherein: a first one of the component controllers is a queue controller for managing the activities of the temporary storage queue; . a second one of the component controllers is a conveyor controller for managing the activities of the delivery and takeaway means; a third one of the component controller is a table controller .for managing the activities of the work tables. 52. A control system as recite in Claim 51 wherein the controlled work station further includes a rotational consolidation queue adapted to receive a multiplicity of totes and to individually open said totes to allow the operator access thereto, the component controllers further including a consolidation controller for managing the activities of the rotational consolidation queue. 53. A method of operating a system for consolidating various articles, the method making use of a system that includes a work area adapted to provide an operator with access to a plurality of containers that carry the articles and a rotational consolidation queue having a multiplicity of shelves each adapted to hold a plurality of totes for receiving articles, the consolidation queue being disposed in close proximity to the work area to enable the operator to readily work back and forth between the work area and the consolidation queue and including means for loading said totes onto a fixed loading shelf to provide the operator access to the totes, the method comprising the steps of: receiving a multiplicity of orders for various articles and automatically ' designating particular totes to receive specific ordered articles; automatically delivering to the work area a plurality containers holding ordered articles; selecting particular articles disposed within a container in the work area for distribution and informing the operator of the selected articles involved and the location of the active container that holds the selected articles; rotating the consolidation queue until a shelf holding a tote designated to receive the selected articles is disposed adjacent the fixed loading shelf; automatically loading a tote designated to receive the selected articles, informing the operator of the quantity of the selected articles that are to be placed into the open tote, inserting the ordered number of the articles into the open tote and then closing the opened tote; repeating the opening of the tote and queue rotating steps as necessary to distribute the selected articles; and repeating the selection, queue rotating and opening of the tote steps as necessary to consolidate all of the ordered articles into the totes. 54. A method as recited in Claim 53 further comprising the steps of: discharging containers from the work area after all of the articles carried therein that are selected for distribu¬ tion have been distributed; and delivering an additional container to the work area following the discharge of a container from the work area. 55. A method as recited in Claim 54 wherein said discharg- ing of containers and said delivering of additional con¬ tainers is carried out automatically. 56. A method as recited in Claim 55 further comprising the step of arranging the orientation of each container in the work area to position particular compartments within the containers that hold the selected articles nearest to the operator. . 57. A method as recited in Claim 54 further comprising the step of automatically activating a signal light above the active container to inform the operator of the location of the active container. 58. A method as recited in Claim 53 further comprising the step of automatically printing customized invoices for insertion into each tote that is filled. 59. A method as recited in Claim 58 wherein the consolida¬ tion queue has a printer mounted for movement back and forth adjacent the fixed loading shelf, the method further comprising the step of automatically positioning the printer adjacent an open tote that is loaded onto the fixed loading shelf each time an invoice is to ' be placed into the open tote. 60. A method of operating a system for the storage and retrieval of articles, the method making use of a system having various component operating units including a work table area for providing an operator with access to article carrying containers, a randomly accessible temporary storage queue for temporarily holding the containers, conveyor means for interconnecting the operating units, and an electrical communications network having circuitry connected to the other operating units, the system further having provisions for controlling automatic functioning of the operating units responsive to signals applied from the electrical network, the method comprising the steps of: requesting a multiplicity of containers from the storage system for delivery to the temporary storage queue; loading containers received by the work station onto the temporary storage queue; delivering a container to each empty work table to provide the operator with access to the delivered con¬ tainers; discharging the delivered containers from the work tables after the operator is finished working with each particular delivered container; requesting the delivery of an additional designated container from the temporary storage queue to the work area each time a container is discharged from a work table, the container request being generated independent of the order in which the containers were received by the temporary storage queue and delivering the designated container to the work table that discharged a container; requesting the delivery of an additional container from the storage system to the temporary storage queue each time a container is transferred from the temporary storage queue to the work area. 61. A method as recited in Claim 60 wherein a multiplicity of the containers include multiple compartments, the method further comprising the steps of: detecting the orientation of containers delivered to the work tables; and rotating the work tables as necessary to insure that a selected container compartment is presented towards the operator. 62. A method for receiving inventoried articles into a storage system utilizing a work center that includes a randomly accessible temporary storage queue for temporarily storing containers and a work area adapted to provide an operator with access to a plurality of containers that carry the articles and the method comprising the steps of: receiving inventoried articles into the work station; inputting both the identity and the quantity of each article received into a control system; calculating the container compartment size that will be required to hold the received articles, wherein after the articles are identified, the control system automatically checks a weights and measures file to determine whether the measurements of the received articles have previously been recorded and uses the previously recorded measurements to calculate the necessary container compartment size when such measurements are available; checking to determine whether a container having an appropriately sized compartment is disposed in the work area, wherein if a suitably sized container is disposed within the work area, then the controller instructs the operator to place the received articles in an appropriately sized empty compartment, and wherein if no suitably sized container is disposed within the work area, then the controller instructs the operator to place the received articles at a designated temporary storage location and an appropriately sized container is automatically ordered for delivery to the work area.

Inventors: BERNARD CLAY JR, LICHTI ROBERT D SR, LUKKEN STANLEY H, PERRY DANIEL C, BERNARD, CLAY, JR., LICHTI, ROBERT, D., SR., LUKKEN, STANLEY, H., PERRY, DANIEL, C.
Applicants: COMPUTER AIDED SYSTEMS INC, COMPUTER AIDED SYSTEMS, INC.
Application year: 1989
Main classification: B65G1
IPC codes: B65G1