Abstract:
Provided is a multistory parking garage comprising first and second laminated racks arranged to face each other in parallel, first and second warehousing stations arranged adjacent to one end side of each of those laminated racks and having waiting conveyors of the same number of stages as that of the shelves of the laminated racks, transfer shuttles interposed between the first and second laminated racks and between the first and second warehousing stations, a lifting system having first and second lifts for transferring cargoes to and from standby conveyors in the first and second warehousing stations, and a conveyor system for transferring cargoes to and from the first and second lifts. At the same level, the conveying direction of the standby conveyors of the first warehousing station and the conveying direction of the standby conveyors of the second warehousing station are opposite to each other. The conveying direction of some of the standby conveyors in the first warehousing station is opposite to the conveying direction of the remaining standby conveyors in the first warehousing station.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent is a national stage filing under 35 U.S.C. §371 of international application Ser. No. PCT/JP2008/065892 filed in the Japanese Receiving Office on Sep. 3, 2008, the complete disclosure of which is hereby incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Technical Area 
         [0003]    The embodiments disclosed herein relate to a three dimensional automated warehouse that includes at least one pair of layered stacked racks that are oriented parallel to each other and a plurality of transferring shuttles implemented for every layer or every few layers of the stacked racks. The shuttles run in a horizontal direction and transfer packages in and out of the layered stacked racks. The disclosed embodiments also relate to a method of receiving and shipping to and from such a three dimensional automated warehouse. 
         [0004]    2. Technical Background 
         [0005]    A known example of a three dimensional warehouse is described in Patent Bulletin Heisei 5-21802. The three dimensional warehouse described in the Patent Disclosure is comprised of at least one pair of left and right layered stacks of racks, containing multiple layers. A transferring shuttle, which can run in a horizontal direction, is implemented for each layer of the stacked racks. The transferring shuttle is able to insert or extract the package into or from the left and right layered stacked racks. 
         [0006]    The three dimensional automated warehouse described in the Patent Bulletin Heisei 5-21802 contains the receiving station at one end of the layered stacked rack, placed adjacent to the layered stacked rack, and the shipping station at the other end of the layered stacked rack, also placed adjacent to the layered stacked rack. These stations have multiple layers of stand-by conveyors, at the same level as the shelves of the layered stacked racks. Each conveyor can carry only one package at a time. The conveyors on the receiving station move the package towards the layered stacked rack, and the conveyors on the shipping station move the package away from the layered stacked racks. Each transferring shuttle can move up to the stations, and can exchange the package with the stand-by conveyor at the same level as the transferring shuttle. 
         [0007]    An elevator device is implemented adjacent to the receiving and shipping stations, on the side away from the layered stacked racks. The elevator device is comprised of a central mast and elevator platforms placed at the left and right side of the central mast, which can move up and down. Each elevator platform also possesses a conveyor function. The elevator platform at the side of the receiving station can be positioned adjacent to receiving conveyors of an external transferring system; it can receive the package transferred from the receiving conveyor; it can move vertically; and it can then transfer the package to the appropriate stand-by conveyor of the receiving station to wait for further handling. Ultimately, the package is stored in the desired location in the layered stacked racks by the transferring shuttle. On the other hand, the elevator platform on the side of the shipping station can be positioned adjacent to a shipping conveyor of the external transfer system. The package, which is transferred to the stand-by conveyor from the layered stacked racks to the stand-by conveyor of the shipping station, can be delivered to the shipping conveyor. 
         [0008]    In the three dimensional automated warehouse of the prior art described above, the route from the receiving conveyor of the external transfer system to the receiving station is one-way. The route from the shipping station to the shipping conveyor of the external transfer system is also one-way. This creates the problem of the receiving-shipping sequence becoming a single cycle. That is, in the receiving process, for example, after the package is transferred from the receiving conveyor to the stand-by conveyor of the receiving station via the elevator platform, the elevator platform must move back to the receiving conveyor while being empty. Likewise for the shipping process: the elevator platform must move to the stand-by conveyor of the shipping station, while being empty, to receive the next package. It is desirable to avoid such movement of the elevator platform while being empty. 
         [0009]    Also, when the balance of the receiving and shipping quantities is disrupted for an external reason, one of the shipping or receiving devices may be at full capacity or suffer insufficient capacity (over-flow), while the other may be under-utilized. This, combined with the single cycle problem, has become a road block to capacity improvement. 
         [0010]    Furthermore, with the construction of the prior art, if one of the devices is out of order, the response will be difficult and expensive. For example, if the elevator platform of the shipping side is out of order, the shipping would stop because the other elevator platform is exclusively for receiving. Even if the conveyor on the elevator platform on the receiving side and the stand-by conveyors are operated in both normal and reverse direction, the addition of a shipping conveyor to the external transfer system will be required, only to address this out-of-order situation. 
       SUMMARY OF THE INVENTION 
       [0011]    Embodiments of the present invention provide new shipping and receiving methods for a three dimensional automated warehouse, addressing the above-stated problems. 
         [0012]    According to one embodiment, a three dimensional automated warehouse is comprised of first and second layered stacked racks, which contain multiple layers of shelves and are placed facing each other and parallel to each other. Further, first and second shipping and receiving stations are placed at one end of the first and second layered stacked racks, respectively, adjacent to the layered stacked racks, which have the same number of stand-by conveyors as the number of layers of the layered stacked racks. Transferring shuttles may be implemented for every layer or every few layers of the layered stacked racks along with stand-by conveyors, which can run horizontally between the first and second layered stacked racks and between the first and second shipping and receiving stations and which transfer the packages to and from the racks and stations. First and second elevators may be located adjacent to the first and second shipping and receiving stations respectively, on the side of the stations away from the layered stacked racks, which contain the first and second vertically moving platforms, respectively, which transfer the packages to and from the stand-by conveyors of the shipping and receiving station. A transfer system is also provided which transfers the packages to and from the elevator platform. The direction of motion of the stand-by conveyor of the first shipping and receiving station and that of the stand-by conveyor of the second shipping and receiving station on the same level are opposite to each other, and the direction of motion of some of the stand-by conveyors is opposite to that of the rest of the stand-by conveyors of the first shipping and receiving station. 
         [0013]    The direction of motion of the stand-by conveyors of the first shipping and receiving station can be alternated for each layer, or alternated for every few layers. 
         [0014]    The (external) transfer system may be comprised of the first receiving conveyor which transfers the package to the first elevator platform; the first shipping conveyor which receives the package from the first elevator platform; the second receiving conveyor which transfers the package to the second elevator platform; and the second shipping conveyor which receives the package from the second elevator platform. 
         [0015]    The first and the second elevator platforms mentioned above may be of double-decker type with upper and lower platforms. 
         [0016]    The first and the second elevator platforms mentioned above may be constructed so that each of them can carry two or more packages at once. 
         [0017]    It is also favorable to be able to switch the direction of the operation of the stand-by conveyors between normal and reverse. 
         [0018]    The first shipping conveyor may be placed at the same height level as the first receiving conveyor, and the second shipping conveyor may be placed at the same height level as the second receiving conveyor. 
         [0019]    Additional layered stacked racks and shipping and receiving stations can be installed adjacent to the elevator platforms, across from the first layered stacked rack and shipping and receiving stations and the second layered stacked rack and shipping and receiving stations. 
         [0020]    According to another embodiment, an automated warehouse may include first and second layered stacked racks, which contain multiple layers of shelves and which are placed facing each other and parallel to each other; first and second shipping and receiving stations placed at one end of the first and second layered stacked racks respectively, adjacent to the layered stacked racks, which have the same number of stand-by conveyors as the number of layers of the layered stacked racks; transferring shuttles implemented for every layer or every few layers of the layered stacked racks and the stand-by conveyors, which can run horizontally between the first and second layered stacked racks and between the first and second shipping and receiving stations and transfer the packages to and from the racks and stations; first and second elevators located adjacent to the first and second shipping and receiving stations respectively, on the side of the stations away from the layered stacked racks, which contain first and second vertically moving platforms respectively, which transfer the packages to and from the stand-by conveyors of the shipping and receiving stations; and a transfer system which transfers the packages to and from the elevator platforms. A shipping and receiving procedure is included such that if a stand-by conveyor of the first shipping and receiving station is designated for receiving, the stand-by conveyor of the second shipping and receiving station at the same level as said stand-by conveyor of the first shipping and receiving station is designated for shipping, and the stand-by conveyor of the first shipping and receiving station at the level above or below is also designated for shipping. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0021]      FIG. 1  is a perspective drawing of a first embodiment of the three dimensional automated warehouse; 
           [0022]      FIG. 2A  is a schematic drawing showing a left hand side of the three dimensional automated warehouse of  FIG. 1 ; 
           [0023]      FIG. 2B  is a schematic drawing showing a right hand side of the warehouse of  FIG. 1 ; 
           [0024]      FIG. 3  is schematic horizontal cross-section drawing of the three dimensional automated warehouse shown in  FIG. 1 ; 
           [0025]      FIG. 4A  is a schematic diagram of an alternative embodiment showing a configuration where the receiving conveyor and the shipping conveyor of the external transfer system are located high; 
           [0026]      FIG. 4B  is a schematic diagram of another alternative embodiment showing a configuration where the receiving conveyor and the shipping conveyor of the external transfer system are located in the middle; 
           [0027]      FIG. 5  is a schematic drawing showing an embodiment where the elevator platform is of double-decker type; 
           [0028]      FIG. 6  is a schematic drawing showing an embodiment where additional layered stacked racks and shipping and receiving stations are added; 
           [0029]      FIG. 7  is a schematic drawing showing an embodiment where the stand-by conveyors of the shipping and receiving stations have their operating directions reversed every few layers; 
           [0030]      FIG. 8  is a perspective drawing showing another alternative embodiment of a three dimensional automated warehouse; 
           [0031]      FIG. 9A  is a schematic drawing showing the left hand side of the three dimensional automated warehouse of  FIG. 8 ; 
           [0032]      FIG. 9B  is a schematic drawing showing the right hand side of the warehouse of  FIG. 8 ; 
           [0033]      FIG. 10A  is a schematic drawing of an alternative embodiment of the warehouse of  FIG. 8  in which the receiving conveyor and the shipping conveyor of the external transfer system are located high; 
           [0034]      FIG. 10B  is a schematic drawing of another alternative embodiment of the warehouse of  FIG. 8  in which the receiving conveyor and the shipping conveyor of the external transfer system are located in the middle; and 
           [0035]      FIG. 11  is a schematic drawing of an embodiment where additional layered stacked racks and shipping and receiving stations are added to the configuration shown in  FIG. 9 . 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0036]      FIG. 1  is a perspective drawing of a three dimensional automated warehouse  10  according to a first embodiment. As shown in the figure, the three dimensional automated warehouse  10  contains at least one pair of left and right layered stacked racks  12 L and  12 R. Each of the layered stacked racks  12 L and  12 R contain multiple layers ( 5  to  20 , to be concrete) of shelves oriented in the same horizontal direction (front and back in  FIG. 1 ). The layered stacked racks  12 L and  12 R, forming a pair, are oriented parallel to each other and separated by a given distance in between. 
         [0037]    A transferring shuttle  16 , that is mobile in the horizontal direction along the shelves  14 , is implemented between the layered stacked racks  12 L and  12 R for each layer. The transferring shuttle  16 , whose detail is not shown in the drawing, is equipped with a running platform, which can contain a package P on its mid section; a pair of arms installed in the front and back of the running platform, which can extend in the horizontal direction perpendicular to the running direction of the platform (shown as left and right direction in  FIG. 1 ) towards either the left or right side of the platform; and fingers placed at each end of the arms, which can open and close (recede and extend). When the arms are extended towards either the left or right side with the fingers in the closed position, the package P carried on the mid section of the platform can be pushed out, thus the package P can be placed on the shelf  14  at the same height level as the mid section surface of the running platform. Conversely, when the arm is extended into the shelf  14  with the fingers in the open position, then, a finger is put into closed position to hook the package P, and finally the arm is contracted, allowing package P to be retrieved onto the running platform. 
         [0038]    Shipping and receiving stations  18 L,  18 R are located at one end of the layered stacked racks  12 L,  12 R, adjacent to the layered stacked racks. These shipping and receiving stations  18 L,  18 R are equipped with the same number of stand-by conveyors  20  as the number of layers of the shelves  14  in the layered stacked racks  12 L,  12 R. Each of the stand-by conveyors  20  is placed so that its conveying surface is at the same height level as the shelf  14  of the corresponding level, within the layered stacked racks  12 L,  12 R. The direction of operation of the stand-by conveyor  20  is predetermined to be along the front and back direction in  FIG. 1  (see arrows F-B). A number of types and forms can be considered for the stand-by conveyor, but a roller conveyor which allows the package to be loaded on or off in the direction perpendicular to the direction of conveyance is desirable. 
         [0039]    The direction of conveyance of the stand-by conveyors  20  at each of the shipping and receiving stations  18 L,  18 R is alternated for each layer. Furthermore, the direction of conveyance of the stand-by conveyor  20  of the left hand side shipping and receiving station  18 L and that of the stand-by conveyor  20  of the right hand side shipping and receiving station  18 R on the same level are opposite of each other.  FIGS. 2 and 3  show this placement and structure schematically.  FIG. 2A  represents the left hand side including the shipping and receiving station  18 L, etc., while  FIG. 2B  represents the right hand side including the shipping and receiving station  18 R, etc. 
         [0040]    Further elaboration is provided below, but it is desirable to be able to change the direction of conveyance of each of the stand-by conveyors  20  in order to adapt to variations of shipping and receiving procedures and schemes. 
         [0041]    Also, it is desirable for the stand-by conveyor to be able to carry two or more packages P that can be lined up along the direction of conveyance. 
         [0042]    There is a space between the left and right shipping and receiving stations  18 L and  18 R. The transferring shuttle  16  at each level can move into the space between the shipping and receiving stations  18 L and  18 R, and can exchange the packages with the stand-by conveyor  20  at the same level. 
         [0043]    The elevator device  22  is placed adjacent to the shipping and receiving stations  18 L,  18 R, on the side away from the layered stacked racks  12 L,  12 R. The elevator device  22  is comprised of a mast  24  placed in the space between the left and right shipping and receiving stations  18 L,  18 R, and the elevator platforms  26 L,  26 R located at the left and right sides of the mast  24 , which can move up and down. 
         [0044]    The elevator platforms  26 L,  26 R may contain a similar type of conveyor as the stand-by conveyor  20 , the direction of conveyance of which can be switched between towards and away from the shipping and receiving stations  18 L,  18 R. Furthermore, the conveying surface of the elevator platforms  26 L,  26 R can be aligned to that of the stand-by conveyors  20  at any level between and including the lowest and the highest levels of the shipping and receiving stations  18 L,  18 R, by raising and lowering of the elevator platforms  26 L,  26 R. Thus the exchange of the package P between the elevator platforms  26 L,  26 R and the stand-by conveyors  20  of the shipping and receiving stations  18 L,  18 R is possible. 
         [0045]    It may also be desirable to be able to place two or more packages on the elevator platforms  26 L and  26 R. Two or more packages P can be placed side by side along the direction of conveyance in the embodiment of  FIG. 1 . 
         [0046]    An external transfer system  28  is connected to the elevator  22  ( FIG. 1 ). The external transfer system  28  is equipped with upper and lower transfer conveyors  30 L,  30 R;  32 L,  32 R on each side, so that the packages can be transferred to and from the elevator platforms  26 L and  26 R. In the first implementation shown in  FIGS. 1 and 2 , the lower conveyors  30 L,  30 R on each side are receiving conveyors, and the upper conveyors  32 L,  32 R are shipping conveyors. By raising and lowering the elevator platforms  26 L and  26 R on each side, the carrying surface of the elevator platforms  26 L and  26 R can be at the same level as the receiving conveyors  30 L,  30 R or the shipping conveyors  32 L,  32 R. 
         [0047]    It is also possible to reverse the roles and designate the lower conveyors  30 L,  30 R as the shipping conveyors and the upper conveyors  32 L,  32 R as the receiving conveyors. 
         [0048]    It is furthermore possible to designate the conveyor  30 L as the shipping conveyor, the conveyor  30 R as the receiving conveyor, the conveyor  32 L as the receiving conveyor and the conveyor  32 R as the shipping conveyor. 
         [0049]    All of the operations within the three dimensional automated warehouse  10  described above are controlled by a control device which is not shown in the figures. 
         [0050]    The operation of the three dimensional automated warehouse  10  of the construction described above is elaborated in the following. 
         [0051]    Suppose multiple packages P are already stored in the layered stacked racks  12 L and  12 R. The information pertaining to the packages (identification number of each package P and the storage location of each package P, etc.) is stored in the memory of the control device (not shown in figures) which controls all of the operations in the three dimensional automated warehouse  10 . 
         [0052]    When the command to ship is issued to the control device, the control device determines the appropriate sequence of the packages P to be shipped according to the shipping command, and memorizes it as the shipping data. On the other hand, when the package P for storage arrives through the external transfer route, the information on the package is read by bar-code readers, RFID readers, etc., and the control device memorizes this as the receiving data. 
         [0053]    In the construction shown in  FIG. 2 , suppose the package P to be shipped first is on the fourth shelf  14  of the layered stacked rack  12 R. In this case, the control device operates the transferring shuttle  16  at the fourth level and moves it in front of the first package P and retrieves the package P. Next, the transferring shuttle  16  with the first package P loaded on it is moved to the location between the shipping and receiving station  18 L,  18 R where the package P is transferred to the stand-by conveyor  20  at the fourth level of the receiving and shipping station  18 R. 
         [0054]    When the elevator platform  26 R is level with the stand-by conveyor  20  at the fourth level, the package P already on the stand-by conveyor  20  is transferred to the elevator platform  26 R. Then, the elevator platform  26 R is lowered to be level with the right shipping conveyor  32 R of the external transfer system  28 , and the package P on the elevator platform  26 R is sent out to the right shipping conveyor  32 R. Thus the package P is shipped out. 
         [0055]    Next, the control device recognizes the package P to be received first from the receiving data, and guides the package to the right receiving conveyor  30 R of the external transfer system  28 . Then, the elevator platform  26 R is lowered to the level of the receiving conveyor  30 R. The package P to be first received is transferred from the receiving conveyor  30 R to the elevator platform  26 R. The elevator platform  26  is raised to the level where the package P is to be stored so that it is level with the stand-by conveyor  20  of the shipping and receiving station  18 R. The package P is then transferred to the stand-by conveyor  20  and remains in the stand-by state waiting for the transfer. After this, the transferring shuttle  16  on the fourth level is moved when appropriate, and the package P is stored at the prescribed location. 
         [0056]    After the first shipping and receiving are completed, shipping and receiving operations can be conducted in alternating fashion, i.e. the second package to be shipped, the second package to be received, the third package to be shipped, the third package to be received, etc. can be handled in that order. Thus, the raising and lowering of the elevator platforms  26 L,  26 R without any cargo will be minimized. The overall operation in the three dimensional automated warehouse  10  becomes of compound cycle, and the efficiency of shipping and receiving is greatly increased. Furthermore, the similar cycle is employed when it is possible to place multiple packages P on the elevator platforms  26 L,  26 R, but the number of packages processed per cycle is greater than one. For example, when two packages can be placed on each of the elevator platforms  26 L,  26 R, the compound cycle, which is to be repeated, would be comprised of loading of the first package to be shipped from the stand-by conveyor  20  (at the fourth level), loading of the second package to be shipped from the stand-by conveyor  20  (at the second level), unloading of the first and the second packages to be shipped to the shipping conveyor  32 R, moving to the receiving conveyor  30 R, loading of the first and second packages to be received, and unloading of the first and the second packages to be received onto the stand-by conveyors  20 . 
         [0057]    In the above-described situation, the shipping and receiving are well balanced. Even when the balance is off-set, i.e. when there are more shipping than receiving or vice-versa, since the shipping and receiving operations are carried out in alternating fashion at each level and each of the elevator platforms  26 L,  26 R can be used for either shipping or receiving, the loading of each of the elevator platforms  26 L,  26 R is balanced. Thus, the operating efficiency of the equipment and devices such as the elevator platforms  26 L,  26 R is increased, and high capability is realized. 
         [0058]    In the embodiment of  FIG. 1 , two packages P can be held on each of the stand-by conveyors  18 L,  18 R at the shipping and receiving station. Thus a maximum of 4 packages P can be on the stand-by (as shown in  FIG. 3 ). 
         [0059]    Further, in the embodiment of  FIG. 1 , the directions of conveyance of not only the elevator platforms  26 L,  26 R but also the stand-by conveyors  20  at the shipping and receiving stations  18 L,  18 R can be reversed. Thus, when there is no receiving, for example, the stand-by conveyor  20  that is normally used for receiving can be used as the shipping conveyor, as shown with the arrow with the broken line in  FIG. 3 . Since both of the elevator platforms  26 L,  26 R can be utilized for shipping, the shipping capability can be increased. Since two packages P can be loaded onto each of the elevator platforms  26 L,  26 R, the maximum of 4 packages P can be shipped out simultaneously. 
         [0060]    Furthermore, even if one of the elevator platforms  26 L,  26 R, or one of the shipping and receiving stations  18 L,  18 R loses its function, since the direction of conveyance of the stand-by conveyors  20  can be switched, the shipping and receiving operations can be carried out with just one side being functional. Especially for an automated warehouse, the inability to ship is a graver problem than the inability to receive. Thus, all of the stand-by conveyors on the side that is still functioning can be utilized for shipping in order to continue shipping. Also, depending on how shipping and receiving demands change, the conveyors that are switched for shipping use can be reverted back to receiving use, allowing optimum receiving operations to take place. 
         [0061]    Furthermore, the operation of rearranging of the packages P stored in the layered stacked rack  12 L,  12 R can easily be done. For example, it may be desirable to rearrange the packages at night in the order of shipment to facilitate the work the next day. In such case, the packages P can be rearranged through the elevator device  22 , shipping and receiving stations  18 L,  18 R, and the transferring shuffles  16  without having the packages P come out to the external transfer system  28 . For example, consider the case where the package P presently stored on the shelf  14  at the second level of the layered stacked rack  12 L,  12 R is to be moved to the shelf  14  on the fifth level. Here, the package P can be moved onto the left elevator platform  26 L through the stand-by conveyor  20  at the second level of the left shipping and receiving station  18 L. Then, the elevator platform  26 L is raised to the fifth level where the package P is transferred onto the stand-by conveyor  20  at the fifth level of left shipping and receiving station  18 L. The package is then stored in the shelf  14  by the transferring shuttle. In another case, where the package P presently stored in the shelf  14  at the second level of the layered stacked racks  12 L,  12 R is to be moved to the shelf  14  on the fourth level, the package P can be transferred to the left elevator platform  26 L via the stand-by conveyor  20  at the second level of the left shipping and receiving station  18 L, then the left elevator platform  26 L is raised to the third level so that the package can be transferred onto the stand-by conveyor  20  at the third level of the left shipping and receiving station  18 L. The package P is then transferred to the stand-by conveyor  20  at the third level of the right shipping and receiving station  18 R by the transferring shuttle  16 , then to the fourth level by the right elevator platform  26 R and onto the stand-by conveyor  20  on the fourth level of the right shipping and receiving station  18 R, and finally to the shelf  14  on the fourth level by the transferring shuttle  16 . Of course, by changing the direction of conveyance of the stand-by conveyor  20 , the package can be directly transferred from the second to the fourth level. Unlike automated warehouses of the prior art, where the package must come out to the external transfer system in order to be rearranged because the route from receiving to shipping is one-way only, this problem is eliminated in the embodiment of  FIG. 1 . 
         [0062]    In the actual administration of a warehouse, there could be a situation where the package P, which is slated for receiving and storage, may need to be extracted before it is stored. In such case, the package can be directly transferred from the receiving conveyors  30 L,  30 R to the shipping conveyors  32 L,  32 R via the elevator platforms  26 L,  26 R so that such an operation can be executed promptly. 
         [0063]    It will be understood that, in the examples of the method of shipping, receiving, etc. described above, the movement of the package P is not restricted to what has been described above. 
         [0064]    In the embodiments described above, the receiving conveyors  30 R,  30 L and the shipping conveyors  32 R,  32 RL of the external transfer system  28  are placed near the floor level of the three dimensional automated warehouse  10  according to the figures, but these could be placed near the top level as shown in  FIG. 4A  or near the mid level as shown in  FIG. 4B . 
         [0065]    Also, a double-decker type of elevator platform  26 L′ shown in  FIG. 5 , with two (upper and lower) conveyors  34  and  35  can be used. In this case, by setting the vertical distance between the receiving conveyors  30 L,  30 R and the shipping conveyors  32 L,  32 R, the vertical distance between the conveyors  34  and  35  of the elevator platform  26 L′, and the vertical distance between the stand-by conveyors  18 L and  18 R equal to each other, the operation of shipping and receiving can be conducted simultaneously, thus the efficiency is increased. In the construction for this purpose, shown in  FIG. 5 , the vertical position of the receiving conveyor  30 L and that of the shipping conveyor  32 L are reversed from  FIG. 2 . That is, the relative vertical position of the shipping and receiving conveyors can be altered to be optimum. 
         [0066]    Furthermore, in addition to the layered stacked racks  12 L,  12 R, a similar pair of layered stacked racks  112  can be added on the opposite side of the elevator device  22 , such as is shown in  FIG. 6 . 
         [0067]    The transferring shuttles  116  are implemented between the pair of additional layered stacked racks  112  at each level, like the embodiment of  FIG. 1 . Since the receiving conveyors  30 L,  30 R and the shipping conveyors  32 L,  32 R are located below these additional layered stacked racks  112 , its number of levels may be lower than that of the layered stacked racks  12 L,  12 R on the opposite side. 
         [0068]    The shipping and receiving station  118 , similar to the shipping and receiving stations  18 L,  18 R of the embodiment of  FIG. 1 , is placed adjacent to each of the additional layered stacked racks  112 . The shipping and receiving station  118  is situated to face the elevator device  22 . The stand-by conveyors  20 ,  120  at the same height level of the shipping and receiving stations  18 L,  18 R,  118 , which are facing each other across the elevator device  22 , may have the same direction of conveyance. 
         [0069]    In the construction shown in  FIG. 6 , not only the storage quantity and capacity for the package P is higher, but also the rearrangement of the package within the same level can be more easily achieved. Furthermore, for the same floor space, the running coverage area of transferring shuttles  16 ,  116  for the construction shown in  FIG. 6  will be smaller than the first embodiment ( FIG. 1 ), which decreases the motion of the transferring shuttle  16 ,  116  and increases the processing speed of the transferring shuttle  16 ,  116 . 
         [0070]    Also, for example, the packages at the shipping and receiving station  118  on the side of the layered stacked racks  112  can be transferred onto the elevator platforms  26 L,  26 R, at the same time that the packages that are already on the elevator platforms  26 L,  26 R are being transferred to the shipping and receiving stations  18 L,  18 R, and vice-versa. Thus, shipping and receiving can be done in a single stroke, further raising the capability. 
         [0071]    As a variant of the construction shown in  FIG. 6 , the receiving conveyors  30 L,  30 R and the shipping conveyors  32 L,  32 R can be placed at the mid level or at the top level. Also, the double-decker type of elevator platform, shown in  FIG. 5 , can be used in the construction of  FIG. 6 . 
         [0072]    In the above implementation form, the receiving conveyors  30 L,  30 R and the shipping conveyors  32 L,  32 R are laid out on left and right sides, but depending on the shipping and receiving quantity, these can be replaced with one single conveyor whose direction of conveyance can be switched. 
         [0073]    The transferring shuttle  16  is implemented for each level of the layered stacked racks  12 L,  12 R in the above-described implementation. If the transferring shuttle is of the type that can also move in the vertical direction, one transferring shuttle can be implemented for multiple levels. 
         [0074]    The directions of conveyance of the stand-by conveyors  20  at the shipping and receiving stations  18 L,  18 R on each side do not have to be alternated for each layer. It would suffice, for example, if the direction of conveyance of some of the stand-by conveyors  20  of the left shipping and receiving station  18 L is opposite from the rest of the stand-by conveyors  20 . The direction can be altered every few levels, for example, every other layer, or every three layers. (See, for example,  FIG. 7 ) 
         [0075]      FIG. 8  is a perspective drawing of a three dimensional automated warehouse  100  according to yet another embodiment. This three dimensional automated warehouse  100  is fundamentally similar to the three dimensional automated warehouse  10  of the first implementation. The same numbers and markings are assigned to the equivalent parts, and redundant explanation will not be presented. 
         [0076]    As seen in  FIG. 9 , which is the schematic drawing derived from  FIG. 8 , the difference between the three dimensional automated warehouses  10  and  100 , respectively, is that the receiving conveyors  130 L,  130 R and the shipping conveyors  132 L,  132 R are placed on a straight line across the elevator device  22 , for each side of the external transfer system  128 . In the construction shown in  FIGS. 8 and 9 , the shipping conveyors  132 L,  132 R are placed under the layered stacked racks  12 L,  12 R. Thus, when the elevator platforms  26 L,  26 R on each side are lowered to the lowest level, the conveying surfaces of the receiving conveyors  130 L,  130 R, of the elevator platforms  26 L,  26 R and of the shipping conveyors  132 L,  132 R are aligned to form a single surface. 
         [0077]    In such a construction, the method of operations such as shipping, receiving and rearranging or relocation of package P is essentially the same as that described above with respect to warehouse  10 . Consider, for example, the case where the package P, that is to be shipped, is on the elevator platform  26 L,  26 R which is at the same level as the receiving conveyor  130 L,  130 R and the shipping conveyor  132 L,  132 R. The package P on the elevator platform  26 L,  26 R can be transferred onto the shipping conveyor  132 L,  132 R at the same time the package P, that is to be received and is being transferred on the receiving conveyor  130 L,  130 R, is loaded onto the elevator platform  26 L,  26 R. In the embodiment of  FIG. 1 , the elevator platform  26 L,  26 R, which is empty after unloading the package P, had to be brought to the level of receiving conveyor  30 L,  30 R. The embodiment of  FIG. 8  has the advantage of eliminating such wasted motion. 
         [0078]    A variation of the embodiment of  FIG. 8  is shown in  FIG. 10A , in which the receiving conveyors  130 L,  130 R and the shipping conveyors  132 L,  132 R are located above the layered stacked racks  12 L,  12 R. In another embodiment, shown in  FIG. 10B , the receiving conveyors  130 L,  130 R and the shipping conveyors  132 L,  132 R can be placed at the mid level. 
         [0079]    In still another embodiment, such as is shown in  FIG. 11 , a pair of additional layered stacked racks  112 ′ and additional shipping and receiving stations  118 ′ can be placed across from the layered stacked racks  12 L,  12 R and the shipping and receiving stations  18 L,  18 R. Also, if the transferring shuttle  16  is of the type that can also move vertically, one transfer shuttle can be assigned for multiple levels. Furthermore, the direction of conveyance of the stand-by conveyor of the shipping and receiving station does not have to alternate at each level. It could alternate every few levels, for example, every other level or every three levels, as shown in  FIG. 7 . 
         [0080]    Also, although the shipping and receiving stations  18 L,  18 R, the elevator device  22 , and the external transfer system  28 , etc have been described as if they are only on one side of the layered stacked racks  12 L,  12 R, it will be understood that the shipping and receiving station, elevator device, external system, etc., could also be located on the other side as well. 
         [0081]    It will also be understood that the invention is not limited to what is described above, and that numerous variations and alterations are possible within the spirit and scope of this invention, as set forth in the following claims.