Abstract:
In response to a storing command to store a plurality of articles to different storage units of the rack, the control device of article storage facility performs a multiple storing operation wherein the control device controls horizontal movements of the plurality of moving members, vertical movements of the plurality of transfer device provided to each of the plurality of moving members, and transfer operations of the plurality of transfer device in order to cause the plurality of the transfer device: to be at respective storage/retrieval positions; to receive articles from respective article supports; and to move to rack side article transfer positions corresponding to the storage units in which the articles are to be stored and d) to transfer the received articles to the storage units.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to article storage facilities having a article storage rack and moving members such as stacker cranes for transporting articles between the article storage rack and article supports for articles transported in and out. 
   2. Description of Related Art 
   In such article storage facilities, it is required to improve the transport ability in order to shorten the time for storing and retrieving articles. 
   Thus, examples of conventional article storage facilities include a facility that is provided with a vertically movable unit that can be vertically moved with respect to an article-transporting moving member, wherein two article transfer means are aligned in the horizontal direction on the vertically movable unit (see JP 2000-229708A, for example). 
   In this first known structure, it is possible to transfer an article with each of the two article transfer means by horizontally moving the article-transporting moving member and by vertically moving the vertically movable unit, and thus it is possible to transport two articles at the same time with one article-transporting moving member, so that the transport efficiency can be improved. 
   Furthermore, in another conventional article storage facility, two article-transporting moving members are provided in such a manner that they horizontally move on the same track, two support portions for articles transported in and out are provided in such a manner that they are installed on both sides of an article storage rack, one article-transporting moving member among the two article-transporting moving members transports an article between one support portion for articles transported in and out and the article storage rack, and the other article-transporting moving member transports an article between the other support portion for articles transported in and out and the article storage rack (see JP 2002-175117A, for example). 
   In this second known structure, in the horizontal direction, a common area is provided at the middle portion of the article storage rack, and individual areas are provided on both ends of the common area. Either one of the two article-transporting moving members can enter the common area, but a restriction is performed such that the two article-transporting moving members do not enter the common area at the same time, and thus the article-transporting moving members are prevented from colliding against each other. In the two individual areas, the article-transporting moving members can transport articles at the same time, and thus the transport ability can be improved. 
   In the first known structure, the two pieces of article transfer means are aligned in the horizontal direction on the vertically movable unit. Thus, if a command to transport two articles to different storage portions among a plurality of storage portions in the article storage rack is given, or if a command to transport two articles from different storage portions among the plurality of storage portions in the article storage rack is given, then the articles are one by one transferred to and from the different storage portions. 
   More specifically, in a case where two articles are transported to different storage portions, when transferring the two articles to be stored in the different storage portions, first, one piece of article transfer means among the two pieces of article transfer means is positioned at an article transfer position on the rack side corresponding to the storage portion in which an article is to be stored, and the article is taken in by transferring it so as to be stored in the storage portion. Next, the other article transfer means is positioned at an article transfer position on the rack side corresponding to the storage portion in which the other article is to be stored, and the remaining one article is taken in by transferring it so as to be stored in the storage portion. 
   Accordingly, although two pieces of article transfer means are provided on one article-transporting moving member, the transport ability of only one piece of article transfer means can be obtained for transfer to and from the storage portions, and therefore there is the possibility that the transport ability cannot be effectively improved. 
   In the second known structure, although two article-transporting moving members are provided, the two article-transporting moving members cannot enter the common area of the article storage rack at the same time, and thus the two article-transporting moving members cannot transport articles at the same time in the common area. Accordingly, the transport ability of only one article-transporting moving member can be obtained for article transportation to and from a part of the article storage rack in the common area, and therefore there is the possibility that the transport ability cannot be effectively improved. 
   SUMMARY OF THE INVENTION 
   The present invention was arrived at in view of these problems, and it is an object thereof to provide an article storage facility in which the transport ability can be effectively improved. 
   To attain the object of the invention, the article storage facility in accordance with the present invention comprises:
         an article storage rack having a plurality of storage units arranged in horizontal rows and vertical columns;   article supports arranged in a horizontal direction for use in storing articles into and retrieving articles from the article storage rack;   a plurality of moving members movable in a horizontal direction on a single predetermined path for transporting articles between the storage units and the article supports, wherein the plurality of moving members are adapted to be able to be at positions corresponding to the article supports such that the plurality of moving members can transfer articles from or to the corresponding article supports simultaneously;   transfer means provided to each of the plurality of moving members for transferring an article between the storage unit or the article support and the moving member;   control means for controlling operations of the moving members and the transfer means, wherein the control means controls horizontal movement of the moving members and the vertical movements of the transfer means in order to move the transfer means to rack side article transfer positions which correspond to each of the plurality of storage unit or to storage/retrieval transfer positions that correspond to the article supports, wherein the control means further controls transfer operations of the transfer means so that the transfer means can transfer articles from and to the storage units and the article supports at the rack side article transfer positions and storage/retrieval transfer positions respectively,   and further wherein, in response to a storing command to store a plurality of articles to different storage units of the rack, the control means performs a multiple storing operation wherein the control means controls horizontal movements of the plurality of moving members, vertical movements of the plurality of transfer means provided to each of the plurality of moving members, and transfer operations of the plurality of transfer means in order to cause the plurality of the transfer means: a) to be at respective storage/retrieval positions; b) to receive articles from respective article supports; c) to move to rack side article transfer positions corresponding to the storage units in which the articles are to be stored and d) to transfer the received articles to the storage units.       

   In another embodiment, in response to a retrieving command to retrieve a plurality of articles from different storage units of the rack, the control means performs a multiple retrieval operation wherein the control means controls horizontal movements of the plurality of moving members, vertical movements of the plurality of transfer means provided to each of the plurality of moving members, and transfer operations of the plurality of transfer means in order to cause the plurality of the transfer means: a) to be at the rack side article transfer positions corresponding to the storage units from which the articles are to be retrieved; b) to transfer articles from respective article units; c) to move to corresponding article supports, and d) to transfer the retrieved articles to the article supports. 
   Thus, storing and retrieval operations of articles are made efficient by making more efficient use of a plurality of moving members. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an article storage facility in a first embodiment. 
       FIG. 2  is a side view of stacker cranes in the first embodiment. 
       FIG. 3  is a block diagram of the article storage facility in the first embodiment. 
       FIG. 4  is a view showing the operation of the stacker cranes in a simultaneous storage operation (multiple storage operation). 
       FIG. 5  is a view showing the operation of the stacker cranes in a first individual storage operation. 
       FIG. 6  is a view showing the operation of the stacker cranes in a second individual storage operation. 
       FIG. 7  is a view showing the operation of the stacker cranes in a simultaneous retrieval operation (multiple retrieval operation). 
       FIG. 8  is a view showing the operation of the stacker cranes in a first individual retrieval operation. 
       FIG. 9  is a view showing the operation of the stacker cranes in a second individual retrieval operation. 
       FIG. 10  is a flowchart showing the control operation of control means. 
       FIG. 11  is a table indicating processes that are performed when commands to transport a plurality of articles in, to transport a plurality of articles out, and to transport articles in and out are given. 
       FIG. 12  is a table indicating processes that are performed when commands to transport one article in and to transport one article out are given. 
       FIG. 13  is a side view of an article storage facility in a second embodiment. 
       FIG. 14  is a side view of stacker cranes in a third embodiment. 
       FIG. 15  is a side view of the main portions of the stacker cranes in the third embodiment. 
       FIG. 16  is a vertical cross-sectional view of the main portions of the stacker cranes in the third embodiment. 
       FIG. 17  is a plan view of the main portions of the stacker cranes in the third embodiment. 
       FIG. 18  is an enlarged view of the main portions in  FIG. 15 . 
       FIG. 19  is an enlarged view of the main portions in  FIG. 16 . 
       FIG. 20  is an enlarged view of the main portions in  FIG. 18 . 
       FIG. 21  is an enlarged view of the main portions in  FIG. 19 . 
   

   DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
   Embodiments of an article storage facility according to the present invention are described based on the drawings. 
   First Embodiment 
   First, an article storage facility in a first embodiment is described. As shown in  FIG. 1 , the article storage facility has article storage racks  2  in which a plurality of storage units  1  are aligned in the vertical direction and in the horizontal direction, and stacker cranes  4  as article-transporting moving members for transporting articles B between the article storage rack(s)  2  and article supports  3  where articles to be stored and retrieved articles are supported. 
   A plurality of pairs of front and rear support posts  5  are arranged upright with spacings interposed therebetween in the horizontal direction in the article storage racks  2 , and a plurality of placing support portions  6  that extend in the horizontal direction are arranged with spacings interposed therebetween in the vertical direction on each pair of front and rear support posts  5 . 
   One storage unit  1  is constituted by the pair of front and rear support posts  5  and the pair of left and right placing support portions  6 , and the plurality of storage units  1  are aligned in the vertical direction and in the horizontal direction. 
   Two article storage racks  2  are installed with a spacing interposed therebetween such that their directions in which articles are taken in and out are opposed to each other, and two article supports  3  are installed so as to be opposed to each other with a spacing interposed therebetween at the location adjacent to the article storage racks  2  in the horizontal direction, such as the location on the side of the article storage racks  2 . 
   A travel rail  7  as a predetermined path or track extends the entire length of the article storage racks  2  in the horizontal direction and the article supports  3  is installed on the floor face between the two article storage racks  2 , and a guide rail  8  extending across the entire area of the article storage racks  2  in the horizontal direction and the article supports  3  is installed on the upper side. Furthermore, the stacker cranes  4  are provided so as to horizontally move on the travel rail  7  while being guided by the guide rail  8 . 
   The end portion, among both end portions of the travel rail  7 , on the side of the article supports  3  is provided with a ground-side controller  9  for managing the operation of the stacker cranes  4 . The ground-side controller  9  manages storage information indicating, for example, which article is stored in which storage unit  1 . In the present description, the expressions a controller, a controlling device, controlling portion represents a device that has a CPU, memory, and other necessary components such as a communication circuit for controlling various devices. The various control portions may represent a part of an algorism or functions of the algorism carried out by such a controlling device or devices. All of the controlling functions may be performed by one controlling unit or may be performed by separate controlling units. 
   Two stacker cranes  4  are provided in such a manner that they horizontally move on the same travel rail  7 . As shown in  FIG. 2 , each of the two stacker cranes  4  is constituted by a horizontally movable travel vehicle  10  that travels along the travel rail  7 , a vertically movable unit  11  that can be vertically moved with respect to the travel vehicle  10 , and a transfer apparatus  12  (such as a fork-type transfer apparatus) as article transfer means that is provided on the vertically movable unit  11 . Any one of various known transfer apparatus may be employed for the purposes of the present invention other than the fork-type transfer apparatus where two pairs of arms extend telescopically from the vertically moving unit by means of driving chains. One disclosed in US Patent Application Publication 2005/0036858A1 may be employed, which application is incorporated herein by reference. 
   The stacker cranes  4  are configured so as to perform a storage operation in which the articles B present at the article supports  3  are put in the storage units  1  of the article storage racks  2 , or to perform a retrieval operation in which the articles B that are stored in the storage units  1  of the article storage racks  2  are taken out to the article supports  3 , by horizontally moving the travel vehicles  10 , by vertically moving the vertically movable units  11 , and by letting the transfer apparatuses  12  perform a transferring operation. 
   As shown in  FIG. 1 , as the article supports  3 , two article receiving platforms  13  on which the articles B are placed are provided in such a manner that they are aligned in the horizontal movement direction of the stacker cranes  4 . In this manner, the article supports  3  are configured such that the articles B can be transferred between the article receiving platforms  13  and the transfer apparatuses  12  that are respectively provided on the two stacker cranes  4  when the stacker cranes  4  are aligned in the horizontal movement direction. 
   In the first embodiment, among the two stacker cranes  4 , one positioned closer the article supports  3  is referred to as a first stacker crane  4   a , and the other positioned on the side of the article storage racks  2  is referred to as a second stacker crane  4   b.    
   Among the two article receiving platforms  13 , one positioned on the side away from the article storage racks  2  is referred to as a first article receiving platform  13   a , and the other positioned on the side closer to the article storage racks  2  is referred to as a second article receiving platform  13   b.    
   The first stacker crane  4   a  transports an article between the first article receiving platform  13   a  and the article storage racks  2 , and the second stacker crane  4   b  transports an article between the second article receiving platform  13   b  and the article storage racks  2 . 
   A single vertical post (mast)  14  for guiding and supporting the vertically movable unit  11  such that it can be vertically moved is disposed upright on the travel vehicle  10 , and the vertical post  14  is disposed upright on the opposite side of the position of the other stacker crane  4  in the horizontal movement direction of the stacker cranes  4 , that is in a region substantially spaced apart from the end closer to the other stacker crane. 
   The vertically movable unit  11  is suspended and guided by an elevation chain  15 , and the elevation chain  15  is wound over a guide sprocket  17  that is provided on an upper frame  16  guided along the guide rail  8  and a guide sprocket  18  that is provided on the lower side of the vertical post  14 , and is connected to a take-up drum  19  that is mounted on one end of the travel vehicle  10 . 
   A motor  20  for elevation of an inverter-type drives the take-up drum  19  to rotate forward and in reverse, so that the elevation chain  15  is reeled off and wound up, thereby vertically moving the vertically movable unit  11 . Other conventional device, including a use of a motor mounted to the vertically movable unit  11  to rotate a gear that engages with engaging teeth provided to the vertical post  14 , may be used for the purpose of vertically moving the vertically movable unit  11 . 
   The travel vehicle  10  is provided with a laser vertical range finder  21  for emitting a light beam for measuring the distance in the horizontal direction, and a mirror  23  for bending the path of the light beam emitted by the laser vertical range finder  21  upward in the vertical direction and projecting the light beam on a reflection plate  22  that is installed on the lower face of the vertically movable unit  11 . 
   The laser vertical range finder  21  is configured so as to detect the vertical position of the vertically movable unit  11  on the vertical route, by taking the arrangement position of the mirror  23  provided on the travel vehicle  10  as a reference position in the vertical direction of the vertically movable unit  11 , and by detecting the distance between the reference position and the vertically movable unit  11 . 
   Furthermore, the travel vehicle  10  is provided with two front and rear wheels  24  that can travel on the travel rail  7 . Among the two wheels  24 , one wheel on one end side in the horizontal movement direction is configured as a driving wheel  24   a  that is driven by an electric travel motor  25  of an inverter-type, and the other wheel on the other side in the horizontal movement direction is configured as a driven wheel  24   b  that can freely rotate. 
   The travel vehicle  10  is horizontally moved by driving the driving wheel  24   a  to rotate forward and in reverse with the electric travel motor  25 . 
   The travel vehicle  10  is provided with a laser horizontal range finder  26  for emitting a light beam for measuring the distance in the horizontal direction, and a reflection plate  27  for reflecting the light beam from the laser horizontal range finder  26  is provided at each of both end portions of the travel rail  7 . 
   The laser horizontal range finder  26  is configured so as to detect the horizontal position of the travel vehicle  10  on the horizontal route, by emitting a light beam toward the reflection plate  27  that is installed on the ground side, thereby detecting the distance of the travel vehicle  10  from the end portions of the travel rail  7 . 
   As shown in  FIG. 3 , each of the two stacker cranes  4  is provided with a crane control device  28  for controlling the operation of the stacker crane  4 , and information detected by the laser vertical range finder  21  and information detected by the laser horizontal range finder  26  are input to the crane control device  28 . 
   The configuration of a first crane control device  28 A in the first stacker crane  4   a  is similar to that of a second crane control device  28 B in the second stacker crane  4   b.    
   The crane control device  28  is configured so as to control the horizontal movement of the travel vehicle  10  and the vertical movement of the vertically movable unit  11  such that the transfer apparatus  12  is moved to article transfer positions on the rack side respectively corresponding to the plurality of storage units  1  and an article transfer position on the storage/retrieval side corresponding to the article support  3 , and so as to control the transferring operation of the transfer apparatus  12  such that the transfer apparatus  12  transfers an article to and from the storage units  1  and the article support  3  at the article transfer positions on the rack side and the article transfer position on the storage/retrieval side. 
   Describing more specifically, each of the article transfer positions on the rack side and the article transfer position on the storage/retrieval side is a position that is determined by a target vertical stop position and a target horizontal stop position. The article transfer position on the storage/retrieval side is determined for each of the two article receiving platforms  13 , and the target vertical stop position and the target horizontal stop position are set for each of the two article receiving platforms  13 . The article transfer positions on the rack side are determined respectively for the plurality of storage units  1 , and the target vertical stop position and the target horizontal stop position are set for each of the plurality of storage units  1 . 
   The crane control device  28  is constituted by, for example, a horizontal movement control portion  28   a  for controlling horizontal movement, in which the horizontal movement of the travel vehicle  10  is controlled such that the travel vehicle  10  is traveled to the target horizontal stop position specified by the command, based on information detected by the laser horizontal range finder  26 , a vertical movement control portion  28   b  for controlling vertical movement, in which the vertical movement of the vertically movable unit  11  is controlled such that the vertically movable unit  11  is vertically moved to the target vertical stop position specified by the command, based on information detected by the laser vertical range finder  21 , and a transferring operation control portion  28   c  for controlling transferring operation, in which the transferring operation of the transfer apparatus  12  is controlled such that an article is on the side of the storage units  1  and the article support  3 . 
   In the control on the horizontal movement by the horizontal movement control portion  28   a , the operation of the electric travel motor  25  is controlled such that the horizontal movement of the travel vehicle  10  is started by starting the operation of the electric travel motor  25 , and when the horizontal position of the travel vehicle  10  that is detected by the laser horizontal range finder  26  reaches the target horizontal stop position specified by the command, the travel vehicle  10  is stopped at the target horizontal stop position by applying the brake thereon by stopping the operation of the electric travel motor  25 . 
   In the control on the vertical movement by the vertical movement control portion  28   b , the operation of the motor  20  for elevation is controlled such that the vertical movement of the vertically movable unit  11  is started by starting the operation of the motor  20  for elevation, and when the vertical position of the vertically movable unit  11  that is detected by the laser vertical range finder  21  reaches the target vertical stop position specified by the command, the vertically movable unit  11  is stopped at the target vertical stop position by applying the brake thereon by stopping the operation of the motor  20  for elevation. 
   In the control on the transferring operation by the transferring operation control portion  28   c , the transferring operation of the transfer apparatus  12  is controlled such that by operating the transfer apparatus  12  of a fork-type, the fork is projected to scooping up the article B or putting down the article B, and then the fork is withdrawn. 
   Various types of information can be communicated between the crane control devices  28  and the ground-side controller  9 . Various commands are given by the ground-side controller  9  to the two crane control devices  28 , namely the first crane control device  28 A and the second crane control device  28 B. 
   The crane control devices  28  perform a storage operation in which the articles B present at the article supports  3  are put in the storage units  1  of the article storage racks  2 , or to perform a retrieval operation in which the articles B that are stored in the storage units  1  of the article storage racks  2  are taken out to the article supports  3 , by performing the control on the horizontal movement by the horizontal movement control portion  28   a , the control on the vertical movement by the vertical movement control portion  28   b , and the control on the transferring operation by the transferring operation control portion  28   c  based on the commands from the ground-side controller  9 . 
   Control means H for controlling the operation of the plurality of stacker cranes  4  in this manner is constituted by the ground-side controller  9  and the two crane control devices  28 . 
   Processes that can be performed by the control means H are described. 
   The control means H can perform three types of storage operations, which are a simultaneous storage operation (multiple storage operation), a first individual storage operation, and a second individual storage operation, as storage operations, and can perform three types of retrieval operations, which are a simultaneous retrieval operation (multiple retrieval operation), a first individual retrieval operation, and a second individual retrieval operation, as retrieval operations. 
   Hereinafter, each of the processes is described based on  FIGS. 4 to 9 . 
     FIGS. 4 to 9  are partially omitted side views of the article storage facility, in which the article supports  3  are positioned on the left end, and the article storage racks  2  are positioned on the right side of the article supports  3 . 
   First, the simultaneous storage operation is described based on  FIG. 4 . The simultaneous storage operation is a storage operation that is performed by the two stacker cranes  4 , namely the first stacker crane  4   a  and the second stacker crane  4   b.    
   It should be noted that when the simultaneous storage operation (multiple storage operation) is performed, the articles B are placed on both the first article receiving platform  13   a  and the second article receiving platform  13   b , and, among the two articles B, the article B that is to be stored on the further side into the article storage racks  2  is placed on the second article receiving platform  13   b.    
   The control means H controls the horizontal movement of the first stacker crane  4   a  and the second stacker crane  4   b , the vertical movement of the two transfer apparatuses  12 , and the transferring operation of the two transfer apparatuses  12  such that receiving transfer is performed in which as indicated by the broken lines in the drawing, the two transfer apparatuses  12  that are respectively provided on the first stacker crane  4   a  and the second stacker crane  4   b  are positioned at the article transfer positions on the storage/retrieval side, and the articles B are received by the two transfer apparatuses  12  from the article supports  3 , and then transfer is performed in which as indicated by the solid lines in the drawing, the two transfer apparatuses  12  that are respectively provided on the first stacker crane  4   a  and the second stacker crane  4   b  are positioned at the article transfer positions on the rack side corresponding to the storage units  1  in which the received articles B are to be stored in the article storage racks  2 , and the received articles B are put in the storage units  1 . 
   Describing more specifically, the ground-side controller  9  gives storing commands to both the first crane control device  28 A in the first stacker crane  4   a  and the second crane control device  28 B in the second stacker crane  4   b.    
   The storing command to the first crane control device  28 A is a command to put, in the storage unit  1 , the article B that is placed on the first article receiving platform  13   a , and the target vertical stop positions and the target horizontal stop positions with respect to the article transfer position on the storage/retrieval side corresponding to the first article receiving platform  13   a  and the article transfer position on the rack side corresponding to the storage unit  1  in which the article B is to be stored are specified by the command. 
   The storing command to the second crane control device  28 B is a command to put, in the storage unit  1 , the article B that is placed on the second article receiving platform  13   b , and the target vertical stop positions and the target horizontal stop positions with respect to the article transfer position on the storage/retrieval side corresponding to the second article receiving platform  13   b  and the article transfer position on the rack side corresponding to the storage unit  1  in which the article B is to be stored are specified by the command. 
   The commands are given such that with respect to the storage units  1  in which the articles B are to be stored, the storage unit  1  specified by the storing command to the first crane control device  28 A is closer than the storage unit  1  specified by the storing command to the second crane control device  28 B, to the article supports  3  in the horizontal movement direction of the stacker cranes  4 . 
   The first crane control device  28 A and the second crane control device  28 B are configured so as to perform basically the same processes although the article receiving platforms  13  from which the articles B are received and the storage units  1  in which the articles B are to be stored are different therebetween. 
   In the first crane control device  28 A, first, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that the first stacker crane  4   a  receives the article B that is placed on the first article receiving platform  13   a . Next, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that the first stacker crane  4   a  puts the received article B in the storage unit  1  in which the article is to be stored. 
   In the second crane control device  28 B, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that the second stacker crane  4   b  receives the article B that is placed on the second article receiving platform  13   b , and then the second stacker crane  4   b  puts the received article B in the storage unit  1  in which the article is to be stored. 
   A simultaneous or multiple storage operation may be performed follows. The first end in the following is the end of the rack closer to the article support or article receiving platforms. The second end is the far end of the rack opposite from the article receiving platforms.
         1) placing a first article, to be stored in a first storage unit in a first column closer to the first end, on the first article support;   2) placing a second article, to be stored in a second storage unit in a second column closer to the second end, on the second article support;   3) locating the first vehicle at a position corresponding to the first article support;   4) locating the second vehicle at a position corresponding to the second article support;   5) operating the transfer apparatus of the first vehicle to have the first article supported on the first vehicle;   6) operating the transfer apparatus of the second vehicle to have the second article supported on the second vehicle;   7) causing the second vehicle to move to the second column;   8) causing the first vehicle to move to the first column;   9) causing the vertically moving unit of the second vehicle to move to a position corresponding to the second storage unit before, during, or after the step of causing the second vehicle to move to the second column;   10) causing the vertically moving unit of the first vehicle to move to a position corresponding to the first storage unit before, during, or after the step of causing the first vehicle to move to the first column;   11) operating the transfer apparatus of the second vehicle to transfer the second article to the second storage unit;   12) operating the transfer apparatus of the first vehicle to transfer the first article to the first storage unit.
 
Although numbers are provided above for clarity, they do not necessarily represent the order in which the steps are carried out.
       

   Next, the first individual storage operation is described based on  FIG. 5 . The first individual storage operation is a storage operation that is performed by the first stacker crane  4   a , which is the stacker crane  4  positioned on the side of the article supports  3 , among the two stacker cranes  4 . 
   The control means H controls the horizontal movement of the first stacker crane  4   a , the vertical movement of the transfer apparatus  12 , and the transferring operation of the transfer apparatus  12  such that by operating the first stacker crane  4   a , receiving transfer is performed in which the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the storage/retrieval side corresponding to the support portion for articles transported in and out, and the article B is received by the transfer apparatus  12  from the support portion for articles transported in and out, and then transfer is performed in which the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the rack side corresponding to the storage unit  1  in which the received article B is to be stored in the article storage racks  2 , and the received article B is put in the storage unit  1 . 
   Describing more specifically, the ground-side controller  9  gives a storing command to the first crane control device  28 A, and gives a standby command to the second crane control device  28 B. The standby command is a command to put the second stacker crane  4   b  on standby at that position. 
   In the first crane control device  28 A, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that first, the first stacker crane  4   a  receives the article B that is placed on the first article receiving platform  13   a , and then the first stacker crane  4   a  puts the received article B in the storage unit  1  in which the article is to be stored. 
   In the second crane control device  28 B, the second stacker crane  4   b  is put on standby at that position without performing control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , nor control on the transferring operation by the transferring operation control portion  28   c.    
   Next, the second individual storage operation is described based on  FIG. 6 . The second individual storage operation is a storage operation that is performed by the second stacker crane  4   b , which is the stacker crane  4  positioned on the side of the article storage racks  2 , among the two stacker cranes  4 . 
   The control means H controls the horizontal movement of the second stacker crane  4   b , the vertical movement of the transfer apparatus  12 , and the transferring operation of the transfer apparatus  12  such that by operating the second stacker crane  4   b , receiving transfer is performed in which the transfer apparatus  12  that is provided on the second stacker crane  4   b  is positioned at the article transfer position on the storage/retrieval side corresponding to the support portion for articles transported in and out, and the article B is received by the transfer apparatus  12  from the support portion for articles transported in and out, and then transfer is performed in which the transfer apparatus  12  that is provided on the second stacker crane  4   b  is positioned at the article transfer position on the rack side corresponding to the storage unit  1  in which the received article B is to be stored in the article storage racks  2 , and the received article B is put in the storage unit  1 . 
   Describing more specifically, the ground-side controller  9  gives an HP standby command to the first crane control device  28 A, and gives a storing command to the second crane control device  28 B in the second stacker crane  4   b . The HP standby command is a command to put the first stacker crane  4   a  on standby in a state where the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the storage/retrieval side, and the target vertical stop position and the target horizontal stop position with respect to the article transfer position on the storage/retrieval side corresponding to the first article receiving platform  13   a  are specified by the command. 
   In the first crane control device  28 A, control on the horizontal movement by the horizontal movement control portion  28   a  and control on the vertical movement by the vertical movement control portion  28   b  are performed such that the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the storage/retrieval side corresponding to the first article receiving platform  13   a.    
   In the second crane control device  28 B, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that first, the second stacker crane  4   b  receives the article B that is placed on the second article receiving platform  13   b , and then the second stacker crane  4   b  puts the received article B in the storage unit  1  in which the article is to be stored. 
   Next, the simultaneous retrieval operation (multiple retrieval operation) is described based on  FIG. 7 . The simultaneous retrieval operation is a retrieval operation that is performed by the two stacker cranes  4 , namely the first stacker crane  4   a  and the second stacker crane  4   b.    
   The control means H controls the horizontal movement of the first stacker crane  4   a  and the second stacker crane  4   b , the vertical movement of the two transfer apparatuses  12 , and the transferring operation of the two transfer apparatuses  12  such that take-out transfer is performed in which the two transfer apparatuses  12  that are respectively provided on the first stacker crane  4   a  and the second stacker crane  4   b  are positioned at the article transfer positions on the rack side corresponding to the storage units  1  from which articles are to be taken out in the article storage racks  2 , and the articles B are taken out of the storage units  1  by the plurality of transfer apparatus  12 , and then the two transfer apparatuses  12  that are respectively provided on the first stacker crane  4   a  and the second stacker crane  4   b  are positioned at the article transfer positions on the storage/retrieval side corresponding to the article supports  3 , and the taken out articles B are transferred to the article supports  3 . 
   Describing more specifically, the ground-side controller  9  gives retrieval commands to both the first crane control device  28 A and the second crane control device  28 B. 
   The retrieval command to the first crane control device  28 A is a command to take out, to the first article receiving platform  13   a , the article B that is stored in the storage unit  1 , and the target vertical stop positions and the target horizontal stop positions with respect to the article transfer position on the rack side corresponding to the storage unit  1  from which the article B is to be taken out and the article transfer position on the storage/retrieval side corresponding to the first article receiving platform  13   a  are specified by the command. 
   The retrieval command to the second crane control device  28 B is a command to take out, to the second article receiving platform  13   b , the article B that is stored in the storage unit  1 , and the target vertical stop positions and the target horizontal stop positions with respect to the article transfer position on the rack side corresponding to the storage unit  1  from which the article B is to be taken out and the article transfer position on the storage/retrieval side corresponding to the second article receiving platform  13   b  are specified by the command. 
   The commands are given such that with respect to the storage units  1  from which the articles B are to be taken out, the storage unit  1  specified by the retrieval command to the first crane control device  28 A is closer than the storage unit  1  specified by the retrieval command to the second crane control device  28 B, to the article supports  3  in the horizontal movement direction of the stacker cranes  4 . 
   The first crane control device  28 A and the second crane control device  28 B are configured so as to perform basically the same processes although the storage units  1  from which the articles B are to be taken out and the article receiving platforms  13  to which the taken out articles B are transferred are different therebetween. 
   In the first crane control device  28 A, first, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that the first stacker crane  4   a  takes out the article B that is stored in the storage unit  1 . Next, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that the first stacker crane  4   a  transfers the taken out article B to the first article receiving platform  13   a.    
   In the second crane control device  28 B, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that the second stacker crane  4   b  takes out the article B that is stored in the storage unit  1  different in the horizontal movement direction of the travel vehicles  10 , and then the second stacker crane  4   b  transfers the taken out article B to the second article receiving platform  13   b.    
   A simultaneous or multiple retrieval operation may be carried out as follows. The first end in the following is the end of the rack closer to the article support or article receiving platforms. The second end is the far end of the rack opposite from the article receiving platforms.
     1) causing the second vehicle to move to a second column, that is closer to the second end than a first column is to the second end, in which a target second storage unit belongs;   2) causing the first vehicle to move to a first column, that is closer to the first end than the second column is to the first end, in which a target first storage unit belongs;   3) causing the vertically movable unit of the second vehicle to move to a position corresponding to the second storage unit before, during, or after the step of causing the second vehicle to move to the second column;   4) causing the vertically movable unit of the first vehicle to move to a position corresponding to the first storage unit before, during, or after the step of causing the first vehicle to move to the first column;   5) operating the transfer apparatus of the second vehicle to transfer a second article in the second storage unit to the second vehicle;   6) operating the transfer apparatus of the first vehicle to transfer a first article in the first storage unit to the first vehicle;   7) causing the second vehicle to move to a position corresponding to the second article support;   8) causing the first vehicle to move to a position corresponding to the first article support;   9) operating the transfer apparatus of the second vehicle to have the second article supported on the second article support;   10) operating the transfer apparatus of the first vehicle to have the first article supported on the first article support.   

   Although the numbers are provided above for clarity, they do not necessarily represent the order in which the steps are carried out. 
   Next, the first individual retrieval operation is described based on  FIG. 8 . The first individual retrieval operation is a retrieval operation that is performed by the first stacker crane  4   a.    
   The control means H controls the horizontal movement of the first stacker crane  4   a , the vertical movement of the transfer apparatus  12 , and the transferring operation of the transfer apparatus  12  such that by operating the first stacker crane  4   a , take-out transfer is performed in which the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the rack side corresponding to the storage unit  1  from which an article is to be taken out in the article storage racks  2 , and the article B is taken out of the storage unit  1  by the transfer apparatus  12 , and then the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the storage/retrieval side corresponding to the article support  3 , and the taken out article B is transferred to the article support  3 . 
   Describing more specifically, the ground-side controller  9  gives a retrieval command to the first crane control device  28 A, and gives a standby command to the second crane control device  28 B. 
   In the first crane control device  28 A, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that first, the first stacker crane  4   a  takes out the article B that is stored in the storage unit  1 , and then the first stacker crane  4   a  transfers the taken out article B to the first article receiving platform  13   a.    
   In the second crane control device  28 B, the second stacker crane  4   b  is put on standby at that position without performing control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , nor control on the transferring operation by the transferring operation control portion  28   c.    
   Next, the second individual retrieval operation is described based on  FIG. 9 . The second individual retrieval operation is a retrieval operation that is performed by the second stacker crane  4   b.    
   The control means H controls the horizontal movement of the second stacker crane  4   b , the vertical movement of the transfer apparatus  12 , and the transferring operation of the transfer apparatus  12  such that by operating the second stacker crane  4   b , take-out transfer is performed in which the transfer apparatus  12  that is provided on the second stacker crane  4   b  is positioned at the article transfer position on the rack side corresponding to the storage unit  1  from which an article is to be taken out in the article storage racks  2 , and the article B is taken out of the storage unit  1  by the transfer apparatus  12 , and then the transfer apparatus  12  that is provided on the second stacker crane  4   b  is positioned at the article transfer position on the storage/retrieval side corresponding to the article support  3 , and the taken out article B is transferred to the article support  3 . 
   Describing more specifically, the ground-side controller  9  gives an HP standby command to the first crane control device  28 A, and gives a retrieval command to the second crane control device  28 B. 
   In the first crane control device  28 A, control on the horizontal movement by the horizontal movement control portion  28   a  and control on the vertical movement by the vertical movement control portion  28   b  are performed such that the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the storage/retrieval side corresponding to the first article receiving platform  13   a.    
   In the second crane control device  28 B, control on the horizontal movement by the horizontal movement control portion  28   a , control on the vertical movement by the vertical movement control portion  28   b , and control on the transferring operation by the transferring operation control portion  28   c  are performed such that first, the second stacker crane  4   b  takes out the article B that is stored in the storage unit  1 , and then the second stacker crane  4   b  transfers the taken out article B to the second article receiving platform  13   b.    
   In this manner, the control means H can perform the plurality of processes, and when a command to transport the article B in or out is given, based on the command contents, a process selected from among the plurality of processes that can be performed is performed. 
   The following is a description concerning which process is performed by the control means H, based on the flowchart in  FIG. 10 . 
   In a case where a command to transport the article B in is given, if the command contents are to transport a plurality of articles B to the different storage units  1  for storage, then the control means H performs a storage selection process in which it is selected whether to perform the simultaneous storage operation or to successively perform the first individual storage operations, and performs the process selected in the storage selection process (steps  1  to  4 ). Furthermore, if the command contents are to transport one article B to one storage unit  1  for storage, then the control means H performs the second individual storage operation (steps  5  and  6 ). 
   In a case where a command to transport the article B out is given, if the command contents are to transport a plurality of articles B out by taking them out of the different storage units  1 , then the control means performs a retrieval selection process in which it is selected whether to perform the simultaneous retrieval operation or to successively perform the first individual retrieval operations, and performs the process selected in the retrieval selection process (steps  7  to  10 ). Furthermore, if the command contents are to transport one article B out by taking it out of one storage unit  1 , then the control means H performs the second individual retrieval operation (steps  11  and  12 ). 
   If a command to transport the article B to a particular storage unit  1  for storage and to transport the article B out by taking it out of a particular storage unit  1  is given, then the control means H successively performs the second individual storage operation and the second individual retrieval operation (steps  13  and  14 ). 
   Hereinafter, the cases categorized based on the command contents to transport the article B in or out are each described in more detail. 
   First, the case in which a command to transport a plurality of articles B to the different storage units  1  for storage is given as described in steps  2  to  4  in  FIG. 10  is described. 
   In this case, the control means H performs the storage selection process. In this storage selection process, the control means H selects whether to perform the simultaneous storage operation or to successively perform the first individual storage operations based on the current positions of the two stacker cranes  4  in the horizontal movement direction of the stacker cranes  4 . 
   Describing more specifically, the ground-side controller  9  acquires the current position of the first stacker crane  4   a  and the current position of the second stacker crane  4   b  in the communications with the first crane control device  28 A and the second crane control device  28 B. The ground-side controller  9  selects whether to perform the simultaneous storage operation or to successively perform the first individual storage operations based on the current position of the first stacker crane  4   a  and the current position of the second stacker crane  4   b  that have been acquired. Then, the ground-side controller  9  gives commands to the first crane control device  28 A and the second crane control device  28 B so as to perform the selected process. 
   In this manner, the control means H performs either one selected from among the simultaneous storage operation and the successive individual storage operations based on the current positions of the two stacker cranes  4 . 
   As shown in the table in  FIG. 11 , in the horizontal movement direction of the stacker cranes  4 , if the first stacker crane  4   a  and the second stacker crane  4   b  are positioned at the article supports  3 , if the first stacker crane  4   a  is positioned at the article support  3  and the second stacker crane  4   b  is positioned at the closer-side area of the article storage racks  2 , and if the first stacker crane  4   a  is positioned at the closer-side area of the article storage racks  2  and the second stacker crane  4   b  is positioned at the closer-side area of the article storage racks  2 , then the simultaneous storage operation is performed. 
   If the first stacker crane  4   a  is positioned at the article support  3  and the second stacker crane  4   b  is positioned at the further-side area of the article storage racks  2 , and if the first stacker crane  4   a  is positioned at the article storage racks  2  and the second stacker crane  4   b  is positioned at the further-side area of the article storage racks  2 , then the first individual storage operations are successively performed. 
   In the table in  FIG. 11 , “closer-side area of the article storage racks  2 ” refers to an area, in the horizontal direction in the article storage racks  2 , up to a location away in the horizontal direction by a set distance from the end portion adjacent to the article supports  3 , and the remaining area is taken as “further-side area of the article storage racks  2 ”. 
   Next, the case in which a command to transport one article B to one storage unit  1  for storage is given as described in steps  5  and  6  in  FIG. 10  is described. 
   In this case, as shown the table in  FIG. 12 , the control means H performs the second individual storage operation regardless of the current positions of the first stacker crane  4   a  and the second stacker crane  4   b.    
   Next, the case in which a command to transport a plurality of articles B out by taking them out of the different storage units  1  is given as described in steps  8  to  10  in  FIG. 10  is described. 
   In this case, the control means H performs the retrieval selection process. In the retrieval selection process, the control means H selects whether to perform the simultaneous retrieval operation or to successively perform the first individual retrieval operations based on the current positions of the two stacker cranes  4  in the horizontal movement direction of the stacker cranes  4 . 
   In this manner, the control means H performs either one selected from among the simultaneous retrieval operation and the successive individual retrieval operations based on the current positions of the two stacker cranes  4 . 
   As shown in the table in  FIG. 11 , if the first stacker crane  4   a  and the second stacker crane  4   b  are positioned at the article supports  3 , if the first stacker crane  4   a  is positioned at the article support  3  and the second stacker crane  4   b  is positioned at the closer-side area of the article storage racks  2 , and if the first stacker crane  4   a  is positioned at the closer-side area of the article storage racks  2  and the second stacker crane  4   b  is positioned at the closer-side area of the article storage racks  2 , then the simultaneous retrieval operation is performed. 
   If the first stacker crane  4   a  is positioned at the article support  3  and the second stacker crane  4   b  is positioned at the further-side area of the article storage racks  2 , and if the first stacker crane  4   a  is positioned at the article storage racks  2  and the second stacker crane  4   b  is positioned at the further-side area of the article storage racks  2 , then the first individual retrieval operations are successively performed. 
   Next, the case in which a command to transport one article B out by taking it out of one storage unit  1  is given as described in steps  11  and  12  in  FIG. 10  is described. 
   In this case, as shown in the table in  FIG. 12 , the control means H performs the second individual retrieval operation regardless of the current positions of the first stacker crane  4   a  and the second stacker crane  4   b.    
   Next, the case in which a command to transport the article B to the storage unit  1  in the article storage racks  2  for storage and a command to transport the article B out by taking it out of the storage unit  1  in the article storage racks  2  are given as described in steps  13  and  14  in  FIG. 10  is described. 
   In this case, as shown in the table in  FIG. 11 , the control means H successively performs the second individual storage operation and the second individual retrieval operation regardless of the current positions of the first stacker crane  4   a  and the second stacker crane  4   b.    
   Then, when the second individual storage operation and the second individual retrieval operation are being successively performed, if a command to transport the article B in and a command to transport the article B out by taking it out of the storage unit  1  are newly given, then the control means H judges whether or not it is possible to perform a cut-in process in which the first individual storage operation and the first individual retrieval operation are successively performed before the successive second individual storage operation and second individual retrieval operation end, and if it is possible to perform the cut-in process, then the process is performed. 
   Describing more specifically, the control means H obtains the ordinary process time taken before the transfer apparatus  12  that is provided on the second stacker crane  4   b  is positioned at the article transfer position on the storage/retrieval side by successively performing the second individual storage operation and the second individual retrieval operation, and the cut-in process time taken before the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the article transfer position on the storage/retrieval side when performing the cut-in process in which the first individual storage operation and the first individual retrieval operation are successively performed. If the cut-in process time is shorter than the ordinary process time, then the control means H judges that it is possible to perform the cut-in process. 
   For example, if the second individual storage operation and the second individual retrieval operation are successively performed in this order, then the time taken before the transfer apparatus  12  that is provided on the second stacker crane  4   b  is positioned at the second article receiving platform  13   b  in the second individual retrieval operation is obtained as the ordinary process time. On the other hand, if the first individual storage operation and the first individual retrieval operation are successively performed in this order, then the time taken before the transfer apparatus  12  that is provided on the first stacker crane  4   a  is positioned at the first article receiving platform  13   a  in the first individual retrieval operation is obtained as the cut-in process time. 
   In this manner, when the article transportation is being performed with the second stacker cranes  4   b , if a command to transport the article B in and to transport the article B out is newly given, then the article transportation is possible with the first stacker crane  4   a  currently being in an operation-stop state before the second stacker cranes  4   b  ends the article transportation, instead of waiting for the second stacker cranes  4   b  to end the article transportation and then successively transporting the next article with the second stacker cranes  4   b . Accordingly, the article transportation can be performed with a plurality of stacker cranes  4  at the same time to the extent possible, and thus it is possible to achieve an improvement in the transport ability. 
   Furthermore, the cut-in process as described above can be performed also in a case where a command to transport one article B in is newly given when the second individual storage operation is being performed and a case where a command to transport one article B out is newly given when the second individual retrieval operation is being performed, in addition to the case where a command to transport the article B in and a command to transport the article B out by taking it out of the storage unit  1  are newly given when the second individual storage operation and the second individual retrieval operation are being successively performed. 
   More specifically, the configuration can be such that when a transport process is being performed in which the stacker crane  4  on the side of the article storage racks  2 , among the plurality of stacker cranes  4 , transports the article B, and the remaining stacker cranes  4  are in an operation-stop state, if a command to transport the article B in and to transport the article B out is newly given, then the control means H judges whether or not it is possible to perform the cut-in transport process in which a transport process is performed by operating the stacker cranes  4  currently being in an operation-stop state before the stacker crane  4  currently performing the transport process ends the transport process, and if it is possible to perform the cut-in transport process, then the process is performed. 
   With this configuration, when the article transportation is being performed with the stacker crane  4  that is positioned on the side of the article storage racks  2 , among the plurality of stacker cranes  4 , in a case where a command to transport the article B in and to transport the article B out is newly given, such as a case where commands to transport the article B in and to transport the article B out are successively given, then the article transportation is possible with the stacker cranes currently being in an operation-stop state before the stacker crane  4  currently performing the article transportation ends the article transportation, instead of waiting for the stacker crane  4  currently transporting the article to end the article transportation and then transporting the next article. Accordingly, the transport ability can be improved. 
   Second Embodiment 
   Next, an article storage facility in a second embodiment is described. The second embodiment is another embodiment of the article transfer means that is provided in the article-transporting moving members in the first embodiment. Hereinafter, this article transfer means is described in more detail, and a description of the other components has been omitted because it is similar to that in the first embodiment. 
   As shown in  FIG. 13 , each stacker crane  4  as the article-transporting moving member is provided with a plurality of transfer apparatuses  12  as the article transfer means in such a manner that they are aligned in the vertical direction. 
   Two vertically movable units  11  that are provided with the transfer apparatuses  12  in such a manner that the vertically movable units  11  are aligned in the vertical direction are provided on the travel vehicle  10  in the stacker crane  4 , and the two vertically movable units  11  are provided to be capable of being vertically moved individually with respect to the travel vehicle  10 . 
   If a plurality of articles are transferred to the storage units  1  with different heights for transfer, among the plurality of storage units  1  in the article storage racks  2 , then the control means H controls the vertical movement of the two transfer apparatuses  12  on each of the two stacker cranes  4  and the transferring operation of the two transfer apparatuses  12  such that the plurality of transfer apparatuses  12  are positioned at the article transfer positions on the rack side corresponding to the storage units  1  for transfer, and the articles B are transferred to and from the storage units  1  at which the articles are to be transferred. 
     FIG. 13  shows a side view of the article storage facility in the simultaneous storage operation. 
   Describing more specifically, the vertical movement control portion  28   b  of the crane control device  28  is configured so as to control the vertical movement of the two vertically movable units  11  individually such that the two transfer apparatuses  12  are positioned at the article transfer positions on the rack side corresponding to the storage units  1  with different heights. 
   Furthermore, the transferring operation control portion  28   c  of the crane control device  28  is configured so as to control the transferring operation of the two transfer apparatuses  12  such that articles are respectively transferred to and from the storage units  1  with different heights. 
   Although not shown in the drawings, when a plurality of first article receiving platforms  13   a  and second article receiving platforms  13   b  are stacked in the vertical direction, at the article supports  3 , it is possible to transfer the articles B with the plurality of transfer apparatuses  12  in a state where the plurality of transfer apparatuses  12  are aligned in the vertical direction. 
   In this manner, it is possible to transport a plurality of articles B in or out at the same time with one stacker crane  4 , and in the configuration shown in  FIG. 13 , it is possible to transport up to four articles B in at the same time with two stacker cranes  4 . 
   In the second embodiment, instead of the laser vertical range finder  21 , rotary encoders or other components (not shown) that can rotate as the two vertically movable units  11  are vertically moved are respectively provided on the vertically movable units  11  in order to detect the vertical position of the vertically movable units  11 , and the crane control device  28  detects the vertical position of each of the two vertically movable units  11  based on information detected by the two rotary encoders. 
   Third Embodiment 
   Next, an article storage facility in a third embodiment is described. The third embodiment is another embodiment of the stacker cranes  4  as the article-transporting moving members in the first embodiment. Hereinafter, these stacker cranes  4  are described in more detail, and a description of the other components has been omitted because it is similar to that in the first embodiment. 
   As shown in  FIG. 14 , the single vertical post  14  is disposed upright on the travel vehicle  10 , and the vertical post  14  is disposed upright on the opposite side of the position of the other stacker crane  4  in the horizontal movement direction of the stacker cranes  4 . 
   The travel vehicle  10  of the stacker crane  4  is provided with the front and rear travel wheels  24   a  and  24   b  with a spacing interposed therebetween in the longitudinal direction of the travel rail  7  serving as the track, and among the front and rear travel wheels  24 , the travel wheel  24   a  on the opposite side of the position of the other stacker crane  4  in the horizontal movement direction of the stacker cranes  4  is configured as a driving wheel that is driven by the electric travel motor  25 , and the travel wheel  24   b  on the side of the other stacker crane  4  in the horizontal movement direction of the stacker cranes  4  is configured as a driven wheel that can freely rotate. 
   The configuration of the vertical posts  14  and the configuration of the front and rear travel wheels  24  described above are similar to those in the first embodiment. When the vertical posts  14  that are arranged upright on the travel vehicles  10  are single posts, the width in the fore-and-aft direction of the travel vehicles  10  can be made short, and thus the two stacker cranes  4  can be positioned such that the transfer apparatuses  12  of the two stacker cranes  4  are positioned at the article transfer positions on the rack side respectively corresponding to the storage units  1  that are adjacent to each other in the horizontal direction. Accordingly, if the two storage units  1  in which the articles B are to be put in the simultaneous storage operation are the two storage units  1  that are adjacent to each other in the horizontal movement direction, and if the two storage units  1  from which the articles B are to be taken out in the simultaneous retrieval operation are the two storage units  1  that are adjacent to each other in the horizontal movement direction, the two stacker cranes  4  can transfer the articles B to and from the storage units  1  at the same time. 
   However, in a case where the width in the fore-and-aft direction of the travel vehicle  10  is made short, when the travel vehicle  10  is horizontally moved, due to the inertial force, the travel vehicle  10  is inclined backward when the travel vehicle  10  is accelerated, and the travel vehicle  10  is inclined forward when the travel vehicle  10  is decelerated, and thus there is a possibility that one of the front and rear travel wheels  24   a  and  24   b  moves upward off the travel rail  7 . 
   Thus, each of the front and rear travel wheels  24   a  and  24   b  is provided with restricting wheels  29  for regulating the upward movement of the travel wheel  24   a ,  24   b  off the travel rail  7  by being in contact with the travel rail  7  so as to regulate the upward movement. 
   Hereinafter, the restricting wheels  29  are described in more detail. The restricting wheels  29  that are provided at each of the front and rear travel wheels  24   a  and  24   b  have the same configuration, and thus the restricting wheels  29  that are provided at the travel wheel  24   a  as the driving wheel, among the front and rear travel wheels  24   a  and  24   b , are described based on  FIGS. 15 to 21 . 
   As shown in  FIGS. 15 to 17 , the end portion of the travel vehicle  10  in the fore-and-aft direction is provided with a support frame  30  for supporting the travel the wheel  24  such that the wheel  24  can rotate about the horizontal axis, and the vertical post  14  is disposed upright on the upper portion of the support frame  30 . Furthermore, the support frame  30  is provided with a guide rail  31  for guiding and supporting a guide roller provided on the vertically movable unit  11 . 
   The restricting wheels  29  are supported so as to rotate about the horizontal axes, and are provided with self-energizing adjustment means  32  for adjusting the contact pressure of the restricting wheels  29  with respect to the travel rail  7  by vertically moving the restricting wheels  29 . In addition to the restricting wheels  29 , guide wheel members  33  for guiding the travel vehicle  10  along the travel rail  7  by being in contact with the travel rail  7  so as to limit or restrict the lateral movement are provided. The guide wheel members  33  are supported by guiding support members  45  that are connected to and supported by the support frame  30  such that the guide wheel members  33  can rotate about the vertical axes. 
   The travel wheel  24   a  as the driving wheel is provided so as to be driven to be rotated by the electric travel motor  25 , and is provided with a deceleration mechanism and a braking mechanism (not shown) in addition to the electric travel motor  25 . The drive portions such as the electric travel motor  25 , the deceleration mechanism, and the braking mechanism are covered by a cover (not shown). 
   A ring-shaped traveling tire  24   c  made of urethane rubber is attached to the outer circumferential portion of the travel wheel  24   a . Furthermore, ring-shaped restricting tires  29   a  as elastic members made of urethane rubber are attached to the outer circumferential portions of the restricting wheels  29 . 
   As shown in  FIGS. 16 and 19 , the travel rail  7  is in the shape of a T in which a traveling guide face  7   a  that is in contact with the traveling tire  24   c  of the travel wheel  24   a  is formed on the upper face portion, and a pair of left and right regulating guide faces  7   b  that are in contact with the restricting tires  29   a  of the restricting wheels  29  are formed on the rear side of the traveling guide face  7   a.    
   The restricting wheels  29  are arranged below of the regulating guide faces  7   b  of the travel rail  7 , and are in contact with the regulating guide faces  7   b  of the travel rail  7  from the below, and thus the restricting wheels  29  restrict the upward movement of the travel wheel  24  off the travel rail  7  by being in contact with the travel rail  7  so as to regulate the upward movement. Furthermore, the restricting wheels  29  precisely restrict the upward movement of the travel wheel  24  off the travel rail  7  by being in contact with the travel rail  7  with the contact pressure caused by the elastic force of the restricting tires  29   a.    
   As shown in  FIGS. 18 and 19 , the adjustment means  32  supports the restricting wheels  29  such that the restricting wheels  29  can be vertically moved with respect to the support frame  30 , and adjusts the contact pressure of the restricting wheels  29  with respect to the travel rail  7  using the elastic deformation of the restricting tires  29   a.    
   The adjustment means  32  is constituted by an operation member  35  that is supported by a base holder  34  fixedly supported by the support frame  30  such that the operation member  35  can rotate about the horizontal axis, and a support member  36  that is externally fit to and supported by the operation member  35  and that supports the restricting wheels  29  such that they can rotate about the horizontal axes. 
   As shown in  FIGS. 20 and 21 , the operation member  35  is supported such that it can rotate about a rotation axis X with respect to the base holder  34 , and the support member  36  is supported such that it can swing about a swinging axis Y with respect to the operation member  35 . The rotation axis X of the operation member  35  and the swinging axis Y of the support member  36  are provided in an eccentric state. In this manner, the self-energizing adjustment means  32  is configured as an eccentric cam mechanism. 
   The following is a description concerning the operation of the adjustment means  32 . When the operation member  35  is rotated about the rotation axis X, due to the self-weight of the restricting wheels  29  and the regulation on the upward movement of the restricting wheels  29  at the travel rail  7 , the support member  36  swings about the swinging axis Y with respect to the operation member  35  and thus the support member  36  is vertically moved with respect to the support frame  30  while keeping the posture. 
   The contact pressure of the restricting wheels  29  with respect to the travel rail  7  is adjusted by rotating the operation member  35  about the rotation axis X, thereby adjusting the position of the support member  36  in the vertical direction. 
   Furthermore, lock means  37  capable of switching between a regulation state in which the rotation of the operation member  35  is regulated and a cancellation state in which the regulation on the rotation is cancelled is provided. The lock means  37  is constituted by a protruding engaging portion  38  and dented engaged portions  39  that are engaged with the engaging portion  38 . The state is switched to the regulation state by engaging the engaging portion  38  with the engaged portion  39 , and to the cancellation state by canceling the engagement between the engaging portion  38  and the engaged portion  39 . 
   The engaging portion  38  is formed in such a manner that it projects downward on the front end portion of a rod-shaped adjustment member  40 . To a hole portion formed at the front end portion of a swinging portion  41  supported such that it can swing about the horizontal axis with respect to the base holder  34 , the adjustment member  40  is internally fit such that it can slidingly move. Slide regulating members  42  for regulating the sliding movement of the adjustment member  40  with respect to the swinging portion  41  by being screwed onto the screw portion of the adjustment member  40  and holding the swinging portion  41  therebetween are provided. When the slide regulating members  42  regulate the sliding movement of the adjustment member  40  with respect to the swinging portion  41 , the adjustment member  40  swings together with the swinging portion  41 . Furthermore, a swing regulating member  43  for regulating the swinging of the swinging portion  41  is provided above the front end portion of the adjustment member  40  on which the engaging portion  38  is formed. The swing regulating member  43  is fixed by a bolt  44  in such a manner that it projects from the base holder  34 , and regulates the swinging of the adjustment member  40  by abutting against the adjustment member  40 . 
   The engaged portions  39  are formed at every constant angle (such as ten degrees) on the outer circumferential portion of the operation member  35 , and in total, 19 engaged portions  39  are formed throughout 180 degrees, which is the half of the entire length of the outer circumferential portion of the operation member  35 . 
   The following is a description concerning the operation of the restricting wheels  29  when their contact pressure with respect to the travel rail  7  is adjusted. 
   First, when the bolt  44  that fixes the swing regulating member  43  is loosened or removed, the regulation on the swinging of the adjustment member  40  by the swing regulating member  43  is cancelled. Then, when the swinging portion  41  is swung together with the adjustment member  40  about the horizontal axis, the engagement between the engaging portion  38  and the engaged portion  39  is cancelled. When the engagement between the engaging portion  38  and the engaged portion  39  is cancelled in this manner, it is possible to rotate the operation member  35 , and when the operation member  35  is rotated, the position of the support member  36  in the vertical direction is adjusted, and the contact pressure of the restricting wheels  29  with respect to the travel rail  7  is adjusted. 
   After the contact pressure of the restricting wheels  29  with respect to the travel rail  7  is adjusted, when the swinging portion  41  is swung together with the adjustment member  40  about the horizontal axis, the engaging portion  38  and the engaged portion  39  are engaged with each other. When the engaging portion  38  and the engaged portion  39  cannot be engaged with each other, the slide regulating members  42  are moved in the longitudinal direction of the adjustment member  40 , and thus it is made possible that the adjustment member  40  slidingly moves with respect to the swinging portion  41 . The adjustment member  40  is slidingly moved with respect to the swinging portion  41  such that the engaging portion  38  and the engaged portion  39  can be engaged with each other. Subsequently, in a state where the slide regulating members  42  regulate the sliding movement of the adjustment member  40  with respect to the swinging portion  41  by holding the swinging portion  41  therebetween, when the swinging portion  41  is swung together with the adjustment member  40  about the horizontal axis, the engaging portion  38  and the engaged portion  39  are engaged with each other. 
   When the engaging portion  38  and the engaged portion  39  are engaged with each other, the engagement between the engaging portion  38  and the engaged portion  39  is maintained by fixing the swing regulating member  43  with the bolt  44  and regulating the swinging of the adjustment member  40  with the swing regulating member  43 . 
   Other Embodiments 
   
       
       (1) In the first to third embodiments, the simultaneous storage operation and the simultaneous retrieval operation can be performed by the control means H, but it is also possible that only the simultaneous storage operation can be performed or only the simultaneous retrieval operation can be performed. 
       (2) In the first to third embodiments, if a command to transport a plurality of articles B in is given, then the control means H performs the simultaneous storage operation or successively performs the first individual storage operations, but it is also possible to always perform the simultaneous storage operation if a command to transport a plurality of articles B in is given. 
     
  
   Furthermore, if a command to transport a plurality of articles B out is given, then the control means H performs the simultaneous retrieval operation or successively performs the first individual retrieval operations, but it is also possible to always perform the simultaneous retrieval operation.
     (3) In the first to third embodiments, if a command to transport a plurality of articles B in is given, then the control means H may successively perform the first individual storage operations, but instead of these processes, it is also possible to successively perform the second individual storage operations.   

   Furthermore, if a command to transport a plurality of articles B out is given, it is also possible to successively perform the second individual retrieval operations instead of successively performing the first individual retrieval operations.
     (4) In the first to third embodiments, in the storage selection process, it is selected whether to perform the simultaneous storage operation or to successively perform the first individual storage operations based on the current position of the first stacker crane  4   a  and the current position of the second stacker crane  4   b , but the conditions for the selection are not limited to the current position of the first stacker crane  4   a  and the current position of the second stacker crane  4   b , and it is also possible to make the selection based on various conditions.   

   Furthermore, in the retrieval selection process, the conditions are not limited to the current position of the first stacker crane  4   a  and the current position of the second stacker crane  4   b , and it is also possible to select the simultaneous retrieval operation or the successive first individual retrieval operations based on various conditions.
     (5) In the first to third embodiments, the single vertical post  14  for guiding and supporting the vertically movable unit  11  such that it can be vertically moved is disposed upright on the travel vehicle  10 , but the number of the vertical post  14  that is disposed upright on the travel vehicle  10  can be changed as appropriate, and for example, it is also possible that the vertical posts  14  are arranged upright respectively on both end portions of the travel vehicle  10  in the horizontal movement direction.   (6) In the first to third embodiments, in order to detect the horizontal position of the travel vehicle  10  on the horizontal route and the vertical position of the vertically movable unit  11  on the vertical route, the laser horizontal range finder  26  and the laser vertical range finder  21  are provided, but the configuration for detecting the horizontal position of the travel vehicle  10  on the horizontal route and the vertical position of the vertically movable unit  11  on the vertical route can be changed as appropriate.   

   For example, it is also possible to detect the horizontal position of the travel vehicle  10  on the horizontal route and the vertical position of the vertically movable unit  11  on the vertical route, by providing rotary encoders or other components that can rotate as the travel vehicle  10  travels or the vertically movable unit  11  is vertically moved. 
   Furthermore, when providing the laser horizontal range finder  26 , it is also possible to set the laser horizontal range finders  26  on both end portions of the travel rail  7  and to install the reflection plate  27  on the travel vehicle  10 , in the opposite manner to the first embodiment. In this case, information detected by the laser horizontal range finders  26  is input to the ground-side controller  9 , and the ground-side controller  9  communicates with the crane control device  28  with respect to the horizontal position of the travel vehicle  10 .
     (7) In the first to third embodiments, the examples were shown in which the two stacker cranes  4  are provided, but it is also possible to provide three or more stacker cranes  4 .