Abstract:
A storage apparatus ( 1 ) stores a transported object ( 220 ) from a transporting carriage ( 110 ), which travels along a track ( 120 ) installed on or near a ceiling ( 210 ) while gripping the transported object. The storage apparatus is provided with a rack portion ( 30 ), on which the transported object is put; and a support member ( 10 ), whose upper end is supported by the track or ceiling and whose lower end supports the rack portion. The support member selectively has one of first and second shapes. The first shape allows the transporting carriage to put the transported object onto the rack portion at the predetermined position. The second shape allows the rack portion to move away from a position below the track.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention relates to a storage apparatus for storing a transported object from a transporting carriages, which travels along a track. The track is installed on or near the ceiling in a factory or the like. Here, the “transported object” means a product, an intermediate product, a part, an articles, a work, a partly-finished good, a good or the like, or means a box or container for containing such a product or the like, which has been transported or is to be transported by the apparatus. 
         [0003]    2. Description of the Related Art 
         [0004]    In a manufacturing facility for the semiconductor device for example, a transporting system may be utilized in which a transporting carriage such as an OHT (Overhead Hoist Transport) or the like transports the transported object such as a FOUP (Front—Opening Unified Pod) or the like. The OHT travels along the track installed on or near the ceiling. The FOUP accommodates semiconductor wafers therein. 
         [0005]    Accompanying the transporting system, a storage apparatus such as a storage rack disclosed in Japanese Patent Application Publication Laid Open No. Hei 10-109887 may be utilized, as an apparatus on which the transporting carriage temporarily puts the transported object. In this disclosure, the storage rack has a horizontal rack, which is suspended just under the track, and on which the transported object is put. 
         [0006]    Here, there may be such a case that, while the putting position (i.e., the position to which the transported object is to be put) as for the horizontal direction or directions is positionally-adjusted, the transported object is put on the storage apparatus. For example, if the transported object is FOUP, the pins for positioning, which define the putting position as for the horizontal directions, are fixed on the rack The pins for positioning correspond to the holes for positioning. The holes for positioning are formed on a bottom surface of the FOUP. In case of storing the FOUP on the rack, the FOUP is put on the rack such that the pins for positioning are engaged with the holes for positioning. 
         [0007]    In this manner, in case that the putting position of the transported object as for the horizontal directions is defined, it is necessary to perform a “teaching operation”, which stores or memorizes the horizontal position on the rack into the transporting system, in advance. Namely, when the rack is installed under the track, the operator initiates the mode for the teaching operation and controls the transporting system to (i) move the transported object above the rack and (ii) put the transported object onto the rack while performing such an adjustment that the transported object is positioned at a predetermined horizontal position. By this, for example, the FOUP is put on the rack in such a condition that the pins for positioning on the rack and the holes for positioning on the bottom surface of the FOUP are engaged with each other. Then, the operator controls the transporting system to store or memorize the horizontal position or the adjustment amount of the horizontal position. 
         [0008]    Such a teaching operation is disclosed in Japanese Patent Application Publication Laid Open No. 2006-69687, for example. 
         [0009]    On the other hand, there may be a case that it is necessary to remove the storage apparatus, in order to move the rack away from the space below the track, in case of the maintenance of the transporting carriage, the installation of a facility to the floor where the transporting system has been already installed, and so on. Then, when the once-removed storage apparatus is re-installed, the setting position after the re-installation may be slightly shifted from the original setting position before the removal. In such a case, it becomes necessary to perform the teaching operation again after the re-installation. This results in that the operation load for the removing and re-installing operations accompanied by the teaching operation becomes quite high. Further, if it is necessary to remove the whole or most parts of the storage apparatus, the operation load for the removing and re-installing operations themselves becomes quite high. 
       SUMMARY OF THE INVENTION 
       [0010]    It is therefore an object of the present invention to provide a storage apparatus for storing a transported object, which allows the operation until the re-installation to be performed relatively easily, while the teaching operation after the re-installation is not required even if the rack is temporarily moved or set back. 
         [0011]    The above object of the present invention can be achieved by a storage apparatus for storing a transported object from a transporting carriage, which travels along a track installed on or near a ceiling while gripping the transported object, provided with: a rack portion, on which the transported object is put from said transporting carriage at a predetermined position as for a horizontal direction; and a support member, whose upper end is supported by the track or ceiling and whose lower end supports said rack portion, said support member selectively having one of first and second shapes in such a condition that the upper end is supported by the track or ceiling, said first shape allowing said transporting carriage to put the transported object onto said rack portion at the predetermined position, said second shape allowing said rack portion to move away from a position below said track. 
         [0012]    According to the storage apparatus of the present invention, it is possible to move (e.g., move back, set back or evacuate) the rack portion away from a position below the track by deforming the shape of the support member into the second shape, at the occasion of the maintenance of the transporting carriage or the like. The upper end of the support member may be directly or indirectly supported by the track, and/or directly or indirectly supported by the ceiling. The deformation is performed in such a condition that the upper end of the support member is kept to be supported by the track or ceiling. When the operation such as the maintenance or the like is completed, by returning the shape of the support member into the first shape i.e, the original shape before the deformation, the rack portion can be recovered to such a position or condition that the transporting carriage can put the transported object onto the rack portion at the predetermined position as for a horizontal direction or directions. Therefore, it is not necessary to perform the teaching operation again after the recovery of the rack portion. The operation load can be diminished in comparison with the case that the teaching operation is necessary again. Further, since it is not necessary to remove the whole or most parts of the support member or the storage apparatus, the operation load can be diminished in comparison with the case that the whole or most parts of the support member or the storage apparatus is removed. 
         [0013]    In one aspect of the present invention, said support member comprises: an upper portion, whose upper end is supported by the track or ceiling; and a lower portion, whose upper end is detachably connected with the upper portion and whose lower end supports the rack portion. 
         [0014]    According to this aspect, since each support member has the detachably connected upper and lower portions, at the occasion of the operation such as the maintenance or the like, the lower portion can be separated together with the rack portion from the upper portion, and can be connected to the upper portion again after the operation. Therefore, it is possible to easily realize the support member which can be deformed to displace the rack portion selectively to (i) the position where the transporting carriage can put the transported object onto the rack portion at the predetermined horizontal position and (ii) the position where the rack portion is moved back from the space below the traveling region of the transporting carriage. 
         [0015]    In this aspect, a first restricting surface facing upward may be formed on said upper portion, a second restricting surface facing downward may be formed on said lower portion, and the upper portion and the lower portion may be connected with each other as the second restricting surface abuts to the first restricting surface from above. 
         [0016]    By constructing in this manner, as the second restricting surface of the lower portion abuts to the first restricting surface of the upper portion from above, such a structure is realized that the lower portion can be suspended or hung from the upper portions. Therefore, when the position of the rack portion is recovered to be the original one, the position of the rack portion can be recovered to be the original one. 
         [0017]    In this case, said storage apparatus may further comprise a cover member, which covers a connection portion of the upper portion and the lower portion and whose inner surface has a third restricting surface for restricting a movement of the lower portion with respect to the upper portion as for the horizontal direction. 
         [0018]    By constructing in this manner, the cover member covering the connection portion of the upper and lower portions restricts the upper and lower portions from being shifted to each other by virtue of the third restricting surface. Therefore, when the position of the rack portion is recovered to be the original one, the horizontal position of the rack portion can be certainly recovered to be the original one. 
         [0019]    In the above described aspect related to the upper and lower portions, said storage apparatus may comprise a plurality of support members each of which is said support member. 
         [0020]    By constructing in this manner, the rack portion can be supported in stable by the support members e.g., two, four, six, eight members. Each support member can be disconnected and connected at the connection portion. 
         [0021]    In another aspect of the present invention, said storage apparatus includes two support members each of which is said support member, one of said two support members comprises: a first upper portion, whose upper end is supported by the track or ceiling; and a first lower portion, whose upper end is detachably connected with the first upper portion and whose lower end supports the rack portion, and the other of said two support members comprises: a second upper portion, whose upper end is supported by the track or ceiling at such a position that a traveling region of said transporting carriage seeing from a traveling direction thereof is sandwiched between the first upper portion and the second upper portion; and a second lower portion whose upper end is supported by the second upper portion rotatably in such a direction that the second lower portion departs from a space below the traveling region within a plane perpendicular to the traveling direction, and whose lower end supports the rack portion. 
         [0022]    According to this aspect, the support members are respectively disposed on both sides of the track, seeing from the traveling direction. One support member is constructed such that the upper portion and the lower portion are detachably connected with each other. The other support member is constructed such that the upper portion and the lower portions can be mutually rotated or swung. Therefore, by separating one support member and rotating the lower portion of the other support member, it is possible to easily move (e.g., move back, se back or evacuate) the rack portion away from a position below the track. Also, by rotating the lower portion of the other support member in the direction opposite to the above occasion, from the condition that the rack portion has been moved or evacuated, it is possible to easily recover the rack portion to be such an original position that the transporting carriage can put the transported object onto the rack portion at the predetermined horizontal position. Further, since it is enough to separate just one of the two support members, the moving and recovering operations are easy, and that it is possible to return the rack portion after the recovery to the original position very precisely. 
         [0023]    The above object of the present invention can be also achieved by another storage apparatus for storing a transported object from a transporting carriage, which travels along a track installed on or near a ceiling while gripping the transported object, comprising: a rack portion, on which the transported object is put; and a support member, whose upper end is supported by the track or ceiling and whose lower end supports said rack portion, at least one portion, which supports the rack portion, of said support member being selectively displaced between a first position and a second position, said first position allowing said transporting carriage to put the transported object onto said rack portions, said second position not allowing said transporting carriage to put the transported object onto said rack portion. 
         [0024]    According to another storage apparatus of the present invention, it is possible to easily establish such a condition that the rack portion is moved away from the space below the track, by displacing the support member to the second position, at the occasion of the maintenance of the transporting carriage or the like. When the operation such as the maintenance or the like is completed, it is possible to easily establish such a condition that the rack portion is recovered to be the original position below the track by displacing the support member to the first position, so that the transporting carriage can put the transported object onto the rack portion. Therefore, the operation load can be diminished. 
         [0025]    The nature, utility, and further features of this invention will be more clearly apparent from the following detailed description with respect to preferred embodiments of the invention when read in conjunction with the accompanying drawings briefly described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0026]      FIG. 1  is a front view of a storage apparatus as a first embodiment of the present invention; 
           [0027]      FIG. 2  is a side view of the storage apparatus of  FIG. 1 , seeing from a traveling direction of the transporting carriage; 
           [0028]      FIG. 3A  is an enlarged view of a partially cross section with an internal portion of a region surrounded by a broken line in  FIG. 2 ; 
           [0029]      FIG. 3B  is a B-B sectional view of  FIG. 3A ; 
           [0030]      FIG. 4  is a side view of the storage apparatus of  FIG. 1  in such a condition that a lower brace is separated from an upper brace; and 
           [0031]      FIG. 5A  is a side view of the storage apparatus as a second embodiment of the present invention; 
           [0032]      FIG. 5B  is a B-B sectional view of  FIG. 5A ; 
           [0033]      FIG. 6A  is one side view of the storage apparatus showing a procedure of moving back the rack portion, in the second embodiment; and 
           [0034]      FIG. 6B  is another side view of the storage apparatus showing the moving procedure in the second embodiment. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0035]    Referring to the accompanying drawings, embodiments of the present invention will be now explained. 
       First Embodiment  
       [0036]    A storage apparatus  1  as a first embodiment is explained with referring to  FIG. 1  to  FIG. 4 .  FIG. 1  shows the storage apparatus  1  used with a transporting system  100   
         [0037]    In  FIG. 1 , the transporting system  100  is provided with: a track rail  120 , which is suspended under a ceiling  210  through a fixing member  121 ; and a transporting carriage  110 , which travels along a direction D 1  on the track rail  120 . Bar codes  122 , each of which indicates a position where the transporting carriage  110  is to put a transported object, is attached to the track rail  120 . 
         [0038]    The transporting carriage  110  has a bar-code reader not-illustrated and is capable of reading the information indicated by each of the bar codes  122 . The transporting carriage  110  has a gripper  111 . The gripper  111  is suspended from an upper portion of the transporting carriage  110  through a hoisting (i.e., moving up and down) belt  112 . The transporting carriage  110  moves up and down the gripper  111  along the vertical direction by winding up or winding out the hoisting belt  112 . The transporting carriage  110  is capable of transitionally moving the gripper  111  in a horizontal direction or directions, while stopping on the track rail  120 , and is capable of rotating or swinging the gripper  111  around an axis A. 
         [0039]    The gripper  111  can grip a FOUP  220  and can release the gripped FOUP  220 . The FOUP  220  is a container for containing semiconductor substrates during manufacture or the like. On the bottom surface of the FOUP  220 , a plurality of positioning holes  221  are formed. The positioning holes  221  define the putting position of the FOUP  220  as for the horizontal directions. 
         [0040]    The storage apparatus  1  is provided with a rack  30  (which is an example of the “rack portion” of the present invention) and four braces  10  (each of which is an example of the “support member” of the present invention) for supporting the rack  30  such that the upper surface of the rack  30  may be horizontally arranged. Two braces among the four braces  10  are arranged to be opposed to the other two braces through the track rail  120 . In  FIG. 1 , only two braces  10  on one hand are illustrated. The rack  30  is fixed at the lower end of the brace  10 . Each of the braces  10  has a connection cover  20  as described later. On the rack  30 , a plurality of FOUPs  220  are put. 
         [0041]    On the upper surface of the rack  30 , a plurality of positioning pins  31  are arranged at each putting position of the FOUP  220  on the rack  30 . At each putting position, a set of positioning pins  31  corresponding to a set of positioning holes  221  formed in one FOUP  220  are disposed. The positioning pins  31  in this one set have the mutual positional relationships as for the horizontal directions, which are the same as the mutual positional relationships of the positioning holes  221  in the one set formed in one FOUP  220 . Namely, they have such mutual positional relationships that, if one FOUP  220  is put on the putting position, the positioning holes  221  formed on the one FOUP  220  are just engaged with the positioning pins  31  on the putting position. 
         [0042]    Hereinbelow, one example of a process of installing the storage apparatus  1  to the track rail  120  is explained. First of all, the rack  30  is fixed at the lower end of each of the braces  10 . Next, the upper end of each of the braces  10  is fixed to the track rail  120  through respective one of fixing members  19 . Next, the bar codes  122  are attached to the track rail  122  at the upper positions of the rack  30  on the lower surface of the track rail  120 . The positioning pins  31  are fixed to the vicinity of the perpendicularly downward of the respective bar codes  122  on the upper surface of the rack  30 . Namely, the downward vicinity of the bar codes  122  is set as the putting position. 
         [0043]    In ease that the storage apparatus  1  is set as described above, it is required to perform an operation for teaching the exact positional relationships as for the horizontal direction or directions between (i) the putting position indicated by the bar code  122  and (ii) the positioning pins  31 , to the transporting system  100  (hereinbelow, which will be referred to as “teaching operation”). Hereinbelow, the teaching operation will be explained. 
         [0044]    At first, the transporting carriage  110  is controlled to travel on the track rail  120  while gripping the FOUP  220 , and to reach the bar code  122  indicating a predetermined putting position on the rack  30 . Incidentally, the operation for moving the transporting carriage  110  to the bar code  122  is automatically controlled by the transporting system  100 . 
         [0045]    Next, an operator  501  controls the transporting system  100  by use of a remote controller  502  so that the transporting carriage  100  moves down the gripper  111 . When the bottom surface of the FOUP  220  approaches the positioning pins  31  on the rack  30 , the operator  501  may control the transporting carriage  110  to transitionally move (i.e., move in the horizontal direction or directions) and/or rotationally move the gripper  111  as for the horizontal directions, while the operator  501  visually watches the horizontal positions of the positioning pins  30  and the FOUP  220 . By this, while visually adjusting the mutual positional relationships as for the horizontal directions between the positioning holes  221  and the positioning pins  31 , the FOUP  220  is put onto the rack  30  in such a condition that the positioning holes  221  and the positioning pins  31  are engaged with each other. Then, the transporting system  100  is controlled to memorize the amount of transitionally moving the gripper  111  and the amount of rotationally moving the gripper  111 , until the transporting carriage  110  puts the FOUP  220  onto the rack  30 . The above explained teaching operation is performed for each rack  30  and for each putting position set on the rack  30 . 
         [0046]    On the basis of the above described teaching operations the transporting system  100  transports the FOUP  220  as below. At first, the transporting system  100  controls the transporting carriage  110  to travel to the upside of the FOUP  220 , which is put on a predetermined putting position, and to move the gripper  111  down to the FOUP  220 . Next, the gripper is controlled to grip the FOUP  220  and to be moved up. Next, under a condition that the gripper  111  is gripping the FOUP  220 , while the transporting carriage  110  is controlled to travel on the track rail  120 , the bar codes  122  on the track rail  120  are sequentially read. Then, the transporting carriage  110  is controlled to travel until the bar code  122  indicating the predetermined putting position on the rack  30  is recognized. When the transporting carriage  110  recognizes the bar code  122 , the transporting carriage  110  is controlled to stop on the track rail  120 . Then, the transporting carriage  110  moves down the gripper  111  until the FOUP  220  reaches the rack  30 . Before the FOUP  220  reaches the rack  30 , the gripper  111  is transitionally moved and/or rotationally moved by the moving amount or amounts memorized by the above described teaching operation. By this, the FOUP  220  is exactly put onto the predetermined putting position on the rack  30 , where the positioning holes  221  and the positioning pins  31  are engaged with each other. 
         [0047]    The storage apparatus  1  will be explained in more detail.  FIG. 2  shows the storage apparatus  1  seeing from the traveling direction (i.e., the direction D 1  in  FIG. 1 ) of the transporting carriage  110  of  FIG. 1 .  FIG. 3A  is an enlarged view of a partially cross section with an internal portion of a region (i.e., connection portion of upper and lower braces  11  and  12 ) surrounded by a broken line in  FIG. 2 .  FIG. 3B  is a sectional view along the B-B line of  FIG. 3A . The transporting carriage  110  and the FOUP  220  are omitted in  FIG. 2 . 
         [0048]    In  FIG. 2 , each of the braces  10  has an upper brace  11  and a lower brace  12 . The cross section perpendicular to the length direction of each of the upper brace  11  and the lower brace  12  has a circular shape. The upper brace  11  and the lower brace  12  are connected with each other within a connection cover  20 .  FIG. 3A  shows the internal aspect of the connection cover  20 . A groove  13  is formed in the vicinity of the lower end of the upper brace  11 . A groove  14  is formed in the vicinity of the upper end of the lower brace  12 . The grooves  13  and  14  are formed such that the portion upper than the groove  14  of the lower brace  12  is engaged in the groove  13 , and that the portion lower than the groove  13  of the upper brace  11  is engaged in the groove  14 . As the upper brace  11  and the lower brace  12  are engaged with each other at the grooves  13  and  14 , the upper brace  11  and the lower brace  12  are connected with each other. At this time, a surface  13   a  (which is an example of the “first restricting surface” of the present invention) facing upward within the groove  13  is abut from below to a surface  14   a  (which is an example of the “second restricting surface” of the resent invention) facing downward within the groove  14 . By this, the movement of the lower brace  12  is restricted so that the lower brace  12  is prevented from being dropped. As the structure for connecting the upper brace  11  and the lower brace  12 , various structures may be employed as long as the restricting surfaces capable of restricting the movement of the lower brace  12  to be dropped are formed such as the surfaces  13   a  and  13   b.    
         [0049]    In  FIGS. 3A and 3B , the connection cover  20  is provided with: an upper cover  21 , which is fixed to the vicinity of the lower end of the upper brace  11 ; and a lower cover  22 , which is supported by the upper cover  21 . The upper cover  21  and the lower cover  22  are covers to cover the connection portion of the upper brace  11  and the lower brace  12 . Each of the upper cover  21  and the lower cover  22  is a cylindrical member and is open to both of the up and down directions. 
         [0050]    The upper cover  21  and the lower cover  22  are occlusal with each other within an occlusal area  20   a.  In the occlusal area  20   a,  screw threads are formed on each of an outer surface of the upper cover  21  and an inner surface of the lower cover  22 , so that the screw threads are engaged or occlusal with each other. By rotating the lower cover  22  along a direction D 2  in  FIG. 3B  while fixing the upper cover  21 , it is possible to fix the upper cover  21  to the lower cover  22 , or separate the upper cover  21  from the lower cover  22 . The upper cover  21  is fixed to the upper brace  11 . The lower cover  22  is not fixed to either one of the upper brace  11  and the lower brace  12 . Namely, the lower cover  22  is constructed such that, when the lower cover  22  is separated from the upper cover  21 , the lower cover  22  can freely move in the up and down direction in  FIG. 3A  in such a condition that the lower brace  12  penetrates within the lower cover  22 . Further, each of inner surfaces  22   a  and  22   b  (each of which is an example of the “third restricting surface” of the present invention) of the lower cover  22  is adjusted to have such a shape and a size that the lower brace  12  is shifted as little as possible in the horizontal direction with respect to the upper brace  11  when the lower cover  22  is fixed to the upper cover  21 . 
         [0051]    Further, a reception (i.e., rest or bracket) member  15  is fixed to the lower brace  12 . The reception member  15  is an projection portion, which projects from the external surface of the lower brace  12  toward the external side thereof, and extends along the circumference direction of the lower brace  12  in the cylindrical shape. The reception member  15  is constructed to be wider than the opening of the lower end of the lower cover  22 . By this, the brace  10  is constructed such that, if the lower cover  22  is separated from the upper cover  21  and is dropped, it is received by the reception member  15  and is not further dropped. 
         [0052]    By the above described structure, the upper brace  11  and the lower brace  12  are connected with each other, and the lower cover  22  is fixed to the upper cover  21 . Thus, the lower brace  12  is not dropped, and the movement of the lower brace  12  is restricted so as not to be shifted in the horizontal direction with respect to the upper brace  11 . Therefore, the rack  80 , which is supported by the lower end of each of the lower braces  12 , is not dropped, so that the horizontal position thereof can be precisely maintained. 
         [0053]    Further, at the occasion of the maintenance of the transporting carriage  110  or the like, in case that it is required to move back or evacuate the rack  30  from the space below the traveling region of the transporting carriage  110 , the lower cover  22  is separated from the upper cover  21  as illustrated in  FIG. 4 , and the lower brace  12  is separated from the upper brace  11 . By this, it is possible to easily move back or remove the rack  30 . 
         [0054]    Furthermore, in case that the operation such as the maintenance or the like is completed, the lower brace  12  is connected again with the upper brace  11 , and the lower cover  22  is fixed to the upper cover  21 . By this, it is possible to re-install the rack  30  easily and it is possible after the re-installation to certainly recover the horizontal original position before moving back the rack  30 , since the shift of the lower brace  12  with respect to the upper brace  11  is certainly restricted by the lower cover  22  as described above. Therefore, it is not necessary to perform the teaching operation again, and it is possible to easily perform moving back the rack  30  and recovering it. 
       Second Embodiment 
       [0055]    A storage apparatus as a second embodiment is explained with referring to  FIG. 5A  to  FIG. 6B .  FIG. 5A  shows a storage apparatus  301  as a second embodiment, seeing from the traveling direction of the transporting carriage  110 .  FIG. 5B  is a sectional view of a connection portion  320  of braces  310  in  FIG. 5A . In the second embodiment, the constitutional elements same as those in the first embodiment carry the same reference numerals and the explanations thereof are omitted. 
         [0056]    In  FIG. 5A , the storage apparatus  301  is provided with (i) the rack  30 , to which the positioning pins  31  are fixed, and (ii) four braces for supporting the rack  30 . Each of two braces  10  of those four braces has a structure same as the brace  10  in the first embodiment. Each of rest two braces  310  has a structure different from the brace  10  in the first embodiment. The two braces  10  are opposed to the rest two braces  310  through the track rail  120 .  FIG. 5A  shows only one set of brace  10  and the brace  310 , which are opposed to each other, among the four braces. 
         [0057]    The brace  310  is provided with an upper brace  311  and a lower brace  312 . The upper brace  311  and the lower brace  312  are connected with each other at the connection portion  320 . As illustrated by  FIG. 5B , a rotation shaft  312   a  and a bearing is disposed in the vicinity of the lower end of the upper brace  311  while a bearing  311   a  for the rotation shaft  312   a  is disposed at the upper end of the lower brace  312 . By this, the upper brace  311  and the lower brace  312  are connected or jointed with each other so that the lower brace  312  is capable of rotating or swinging in a direction D 3  in  FIG. 5A  with respect to the rotation shaft  312   a  as the rotation center. Incidentally, the connection portion  320  may be constructed such that the rotation is possible in the clockwise direction from the condition shown in  FIG. 5A  and the rotation is restricted in the anti-clockwise direction from the condition shown in  FIG. 5A . 
         [0058]    A ring  332  is fixed under the brace  12 . A hook  331  is fixed under the ceiling  210  at a position distant from the fixing member  121  in the left direction in  FIG. 5A  for a predetermined distance. 
         [0059]    By the above described structure, in case that it is required to move back the rack  30  from the space below the traveling region of the transporting carriage  110 , the braces  10  are disconnected and the braces  310  are deformed as illustrated in  FIG. 6A  and  FIG. 6B . At first, the lower cover  22  is separated from the upper cover  21 , and the lower brace  12  is separated from the upper brace  11 . Next, the lower brace  312  is rotated in the clockwise direction in  FIG. 6A  with respect to the upper brace  311  with the rotation shaft  312   a  as the rotation center. When the lower brace  312  is rotated until the ring  332  approaches the ceiling  210 , the ring  332  is hooked to the hook  331  as illustrated in  FIG. 6B . In this way, by rotating the lower brace  312  with respect to the upper brace  311  in such a manner that the rack  30  is made distant from the space below the track rail  120  (i.e., the space below the traveling region of the transporting carriage  110 ), it is possible to move back the rack  30  from the space below the track rail  120 . The distance between the hook  331  and the fixing member  121  is adjusted to be such a distance that the ring  332  can be just hooked to the hook  331 . 
         [0060]    Furthermore, in case that the once-moved back rack  30  is re-positioned to the space below the track rail  120 , the braces  10  are connected again and  310  are deformed as following. Namely, the ring  332  is taken out from the hook  331 . Next, the lower brace  312  is rotated in the anti-clockwise direction in  FIG. 6B  with the rotation shaft  312   a  as the rotation center. Next, when the lower brace  312  is rotated until the upper end of the lower brace  12  approaches the lower end of the upper brace  11 , the upper end of the lower brace  12  is connected to the upper brace  11 . Then, the lower cover  22  is fixed to the upper cover  21 . In this way, by rotating the lower brace  312  with respect to the upper brace  311 , it is possible to recover the rack  30  in the space below the track rail  120 . 
         [0061]    As described above, according to the second embodiment, by rotating the lower brace  312  with respect to the upper brace  311 , it is possible to easily perform moving back the rack  30  from the space under the track rail  120  and also easily perform re-installing the rack  30  to the space below the track rail  120 . Further, upon recovering the rack  30 , since the shift of the lower brace  12  with respect to the upper brace  11  is certainly restricted by the lower cover  22  and since the shift of the lower brace  312  with respect to the upper brace  311  is certainly restricted by the connection portion  320  as described above, it is not necessary to perform the teaching operation again after the recover of the rack  30 . Furthers since only two braces i.e., the braces  10  out of four braces are separated from each other, the operations of moving back and recovering the rack  30  are easier than those in the first embodiment. 
       Modified Embodiment  
       [0062]    The above explanations are for the preferred embodiments, to which the present invention is not limited. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. For example, in the above embodiments, the upper end of the brace  10  is fixed to the track rail  120 . Instead, it may be fixed to the ceiling  210 . Further, it may be directly fixed or indirectly (e.g., through a fixing member or the like) fixed to the ceiling  210  or the track rail  120 . 
         [0063]    The entire disclosure of Japanese Patent Application No. 2006-356079 filed on Dec. 28, 2006 including the specification, claims, drawings and summary is incorporated herein by reference in its entirety.