Abstract:
A blank plate has flange portions capable of performing hinge movement around a direction of a shorter side. A blank plate has flange portions capable of performing hinge movement at positions different from the hinge positions of the flange portions, and a side of the blank plate is connected to the flange portions so as to be capable of performing hinge movement. A blank plate has flange portions capable of performing hinge movement at positions different from the hinge positions of the flange portions, and a side of the blank plate is connected to the flange portions so as to be capable of performing hinge movement. First lock mechanisms fix the blank plate and the blank plate perpendicularly to each other. Second lock mechanisms fix the blank plate and the blank plate perpendicularly to each other.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a continuation of International Application No. PCT/JP2011/068895, filed on Aug. 22, 2011, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     The embodiments discussed herein are related to blank plates. 
     BACKGROUND 
     In a computer system, the number of electronic devices such as servers, storages, and network devices increases as the scale of the system becomes larger. If the number of electronic devices increases as described above, a storage frame called rack is used to store efficiently the electronic devices and realize a small footprint. Further, if the electronic devices are to be mounted in the rack, housing-mount rails for mounting the housings of the electronic devices are laid from the front surface to the rear surface of the rack. Then, the housings of the electronic devices are placed on the housing-mount rails and the electronic devices are stacked in the rack. Such a rack is regulated in height of housings to be stored by 1 U. 
     Even if the electronic devices are to be mounted in the rack, it is not requested that the electronic devices are stored in the entire rack. If the electronic devices are not stored in the entire rack, there occurs an empty space at the front side of the rack where no electronic devices are mounted. When there is an open space at the front side of the rack, air exhausted from the electronic devices flows back into the electronic devices, and the electronic devices suck again the returned exhaust air. In this state, the electronic devices are not properly cooled but accumulate heat that may cause a crash of the electronic devices. Thus, blank plates are attached to the space at the front side of the rack to fill the front space. 
     Since there may be spaces of various sizes in the rack, blank plates for 1 U, 2 U, and 3 U are provided to support spaces of all sizes. Conventionally, it is determined a space of what U is open at the front side of the rack, and then a blank plate appropriate for filling the determined space is selected and attached. In the case of adding an electronic device, after the blank panel is removed, the housing is mounted, a blank panel suited for the remaining space is selected, and then the selected blank panel is attached. Meanwhile, removing a mounted electronic device from the rack also requests reselection and attachment of a blank plate. Thus, a plurality of blank plates are prepared at any time and a storage space is secured for the blank plates. In addition, to add or remove a housing, there arises a troublesome labor of replacement and attachment of blank plates. 
     To fill a space open at the front side of a rack, there has been suggested a conventional technique by which, in a rack to which a printed board is attached, two plates formed by corrugated plates or rigid plates are stacked together and placed according to the width of an empty slot to seal the rack. In addition, there has been suggested a conventional technique by which plates with convex and concave portions on both sides are joined together by fitting the convex and concave portions, thereby to adjust the width of the plates and seal the rack to which a printed board is attached. 
     Patent Literature 1: Japanese Laid-open Patent Publication No. 08-307079 
     Patent Literature 2: Japanese Laid-open Utility Model Publication No. 63-131191 
     However, in the case of using the conventional technique by which plates are stacked, a plurality of plates are prepare to support the space sizes of 1 U, 2 U, and 3 U. Furthermore, some blank plates are added or removed. This causes wasteful operations such as securing a storage place for spare or unused blank plates or scrapping of unused blank plates. In the case of using the method in which plates are joined together with convex and concave portions to match the plate size to the space size, a plurality of plates are prepare to support the space sizes of 1 U, 2 U, and 3 U. Furthermore, some blank plates are added or removed. Further, for formation of an appropriate space, troublesome operations are performed such as removing the blank plates, fitting the convex and concave portions, and then attaching the blank plates again. 
     SUMMARY 
     According to an aspect of an embodiment, a blank plate includes: a first plate-like member that has first attachment portions for attachment to support columns of a rack in the vicinity of both longitudinal ends thereof and has both longitudinal end portions including the first attachment portions capable of performing hinge movement around a direction of a shorter side; a second plate-like member that has second attachment portions for attachment to the support columns of the rack in the vicinity of both longitudinal ends thereof, has both longitudinal ends portions including the second attachment portions capable of performing hinge movement around a direction of a shorter side at positions different from the hinge positions of the both longitudinal ends portions of the first plate-like member, and has one longer side to which a longer side of the first plate-like member is connected so as to be capable of performing hinge movement; a third plate-like member that has third attachment portions for attachment to the support columns of the racks in the vicinity of both longitudinal ends thereof, has both longitudinal ends portions including the third attachment portions capable of performing hinge movement around a direction of a shorter side at positions different from the hinge positions of the both longitudinal ends portions of the first plate-like member and the second plate-like member, and has a longer side to which the other longer side of the second plate-like member is connected so as to be capable of performing hinge movement; a first lock mechanism that fixes the second plate-like member and the first plate-like member perpendicularly to each other; and a second lock mechanism in which the third plate-like member performs hinge movement at the side at which the first plate-like member exists with respect to the second plate-like member in a state of being locked by the first lock mechanism to fix the third plate-like member and the second plate-like member perpendicularly to each other. 
     The object and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the claims. 
     It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not restrictive of the invention, as claimed. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a front view of blank plates according to a first embodiment. 
         FIG. 2  is a perspective view of the blank plates according to the first embodiment. 
         FIG. 3  is a rear view of the blank plates according to the first embodiment. 
         FIG. 4  is an upper view of the blank plate according to the first embodiment. 
         FIG. 5A  is a diagram for describing a state of the blank plate in which one flange portion is folded. 
         FIG. 5B  is a diagram for describing a state of the blank plate in which two flange portions are folded. 
         FIG. 6A  is a cross section view of  FIG. 3  taken along line X-X. 
         FIG. 6B  is a diagram for describing the state in which a blank plate  1  is folded. 
         FIG. 6C  is a diagram for describing the state in which blank plates  1  and  2  are folded. 
         FIG. 6D  is a diagram for describing the state in which a blank plate  3  is folded. 
         FIG. 6E  is a diagram for describing the state in which the blank plates  2  and  3  are folded. 
         FIG. 7A  is a perspective view of the folded blank plates  1  and  2  as seen from above. 
         FIG. 7B  is a perspective view of the folded blank plates  1  and  2  as seen from below. 
         FIG. 8  is a cross section view of  FIG. 3  taken along line Y-Y. 
         FIG. 9A  is a diagram for describing a state of a coupling piece coupled to the blank plate  2 . 
         FIG. 9B  is a diagram for describing a state of the coupling piece separated from the blank plate  2 . 
         FIG. 10A  is a rear view of an upper blank plate with the blank plate  2  separated. 
         FIG. 10B  is a rear view of a lower blank plate with the blank plate  2  separated. 
         FIG. 11  is a front view of the blank plates according to the first embodiment attached to a rack. 
         FIG. 12  is a rear view of blank plates according to a second embodiment. 
         FIG. 13  is a cross section view of  FIG. 12  taken along line Z-Z. 
         FIG. 14A  is a diagram for describing the state in which the blank plates according to the second embodiment are not folded. 
         FIG. 14B  is a diagram for describing the state in which a housing is mounted at a position of a blank plate  401 . 
         FIG. 14C  is a diagram for describing the state in which a housing is mounted at a position of blank plates  401  and  402 . 
         FIG. 14D  is a diagram for describing the state in which a hosing is mounted at a position of the blank plate  402 . 
         FIG. 14E  is a diagram for describing the state in which a housing is mounted on a position of the blank plates  402  and  403 . 
         FIG. 14F  is a diagram for describing the state in which a housing is mounted at a position of blank plates  402  to  404 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Preferred embodiments of the present invention will be explained with reference to accompanying drawings.
         However, the blank plates disclosed in the subject application are not limited by the following embodiments.       

     [a] First Embodiment 
       FIG. 1  is a front view of the blank plates according to a first embodiment.  FIG. 2  is a perspective view of the blank plates according to the first embodiment.  FIG. 3  is a rear view of the blank plates according to the first embodiment. In the following descriptions, for the sake of convenience, the left side as seen in  FIG. 1  will be referred to as “upper side,” and the right side as seen in  FIG. 1  as “lower side.” That is, in the following description, the direction of arrow P in  FIG. 1  is a direction moving from the upper to lower sides. In addition, in the following descriptions, for the sake of convenience, the surfaces of blank plates  1  to  3  illustrated in  FIG. 1  will be referred to as “front surfaces,” and the surfaces of the blank plates  1  to  3  illustrated in  FIG. 3  will be referred to as “rear surfaces.” 
     As illustrated in  FIGS. 1 and 2 , the blank plates according to the embodiment include a blank plate  1 , a blank plate  2 , and a blank plate  3 . The blank plate  1  has a plate member  10 , a flange portion  11 A, and a flange portion  11 B. The blank plate  2  has a plate member  201 , a plate member  202 , a flange portion  21 A, and a flange portion  21 B. The blank plate  3  has a plate member  30 , a flange portion  31 A, and a flange portion  31 B. In the embodiment, shorter sides of the blank plates  1  to  3  have a length of 1 U. 
     The plate member  10  and the plate member  201  are coupled together by a coupling portion  40 . The plate member  202  and the plate member  30  are coupled together by a coupling portion  50 . The plate member  10  and the plate member  201  can make hinge movement around the coupling portion  40 . The plate member  202  and the plate member  30  can make hinge movement around the coupling portion  50 . 
     In the embodiment, for example, the plate member  10  and the plate member  201  are attached to a sheet of plastic resin such as polypropylene so that the plate member  10  and the plate member  201  are made foldable. Similarly, the plate member  202  and the plate member  30  are attached to a sheet of plastic resin so that the plate member  202  and the plate member  30  are made foldable. However, the sheet to which the plate member  10 , the plate member  201 , the plate member  202 , and the plate member  30  are attached, may be formed by any flexible material. To form the coupling portion  40  and the coupling portion  50 , alternatively, a portion of one plastic plate including the plate member  10  and the plate member  201  corresponding to the coupling portion  40  may be made thin and foldable, for example. 
     The plate member  202  is provided with rotation shafts  221 A and  221 B. The rotation shafts  221 A and  221 B are rotation shafts for fixing claws to couple the plate member  201  and the plate member  202  as described later. Although described later in detail, the plate member  201  and the plate member  202  are attachable to and detachable from each other by a coupling member. When being coupled together, the plate member  201  and the plate member  202  are fixed to each other. 
     In this arrangement, shorter sides of the plate member  10  and the plate member  30  have a length of 1 U, and a shorter side of the coupled plate members  201  and  202  have a length of 1 U. 
     The plate member  10  and the flange portion  11 A are coupled together by a coupling portion  14 A. The plate member  10  and the flange portion  11 B are coupled together by a coupling portion  14 B. The flange portion  11 A can make hinge movement with respect to the plate member  10  around the coupling portion  14 A. Similarly, the flange portion  11 B can make hinge movement with respect to the plate member  10  around the coupling portion  14 B. 
     The plate member  202  and the flange portion  21 A are coupled together by a coupling portion  24 A. The plate member  202  and the flange portion  21 B are coupled together by a coupling portion  24 B. The flange portion  21 A can make hinge movement with respect to the plate member  202  around the coupling portion  24 A. Similarly, the flange portion  21 B can make hinge movement with respect to the plate member  202  around the coupling portion  24 B. 
     The plate member  30  and the flange portion  31 A are coupled together by a coupling portion  34 A. The plate member  30  and the flange portion  31 B are coupled together by a coupling portion  34 B. The flange portion  31 A can make hinge movement with respect to the plate member  30  around the coupling portion  34 A. Similarly, the flange portion  31 B can make hinge movement with respect to the plate member  30  around the coupling portion  34 B. 
     The coupling portions  14 A,  14 B,  24 A,  24 B,  34 A, and  34 B can be formed by the same method for forming the coupling portion  40  and the coupling portion  50 , for example. 
     The flange portion  11 A is provided with an attachment hole  12 A and a flange fixing claw receiving portion  13 A. The flange portion  11 B is provided with an attachment hole  12 B and a flange fixing claw receiving portion  13 B. The blank plate  1  can be fixed to a support column of the rack by inserting fixing tools such as bolts into the attachment holes  12 A and  12 B and fixing the same to the support column of the rack. The flange fixing claw receiving portions  13 A and  13 B will be described later. 
     The flange portion  21 A is provided with an attachment hole  22 A and a flange fixing claw receiving portion  23 A. The flange portion  21 B is provided with an attachment hole  22 B and a flange fixing claw receiving portion  23 B. The blank plate  2  can be fixed to a support column of the rack by inserting fixing tools such as bolts into the attachment holes  22 A and  22 B and fixing the same to the support column of the rack. The flange fixing claw receiving portions  23 A and  23 B will be described later. 
     The flange portion  31 A is provided with an attachment hole  32 A and a flange fixing claw receiving portion  33 A. The flange portion  31 B is provided with an attachment hole  32 B and a flange fixing claw receiving portion  33 B. The blank plate  3  can be fixed to a support column of the rack by inserting fixing tools such as bolts into the attachment holes  32 A and  32 B and fixing the same to the support column of the rack. The flange fixing claw receiving portions  33 A and  33 B will be described later. 
     As illustrated in  FIG. 3 , the plate member  10  of the blank plate  1  is provided with flange fixing claws  15 A and  15 B and claw receiving portions  16 A and  16 B. The plate member  201  of the blank plate  2  is provided with locking claws  27 A and  27 B. The plate member  202  of the blank plate  2  is provided with flange fixing claws  25 A and  25 B and claw receiving portions  26 A and  26 B. The plate member  30  of the blank plate  3  is provided with flange fixing claws  35 A and  35 B and locking claws  37 A and  37 B. 
     The flange portion  11 A makes hinge movement around the coupling portion  14 A. The flange portion  11 A makes hinge movement toward the rear surface of the plate member  10  and folds until reaching a position perpendicular to the plate member  10 . Then, when the flange portion  11 A is perpendicular to the plate member  10 , the flange fixing claw  15 A and the flange fixing claw receiving portion  13 A fit together. When the flange fixing claw  15 A and the flange fixing claw receiving portion  13 A fit together, the flange portion  11 A is fixed perpendicular to the plate member  10 . 
     The flange portion  11 B makes hinge movement around the coupling portion  14 B. The flange portion  11 B makes hinge movement toward the rear surface of the plate member  10  and folds until reaching a position perpendicular to the plate member  10 . Then, when the flange portion  11 B is perpendicular to the plate member  10 , the flange fixing claw  15 B and the flange fixing claw receiving portion  13 B fit together. When the flange fixing claw  15 B and the flange fixing claw receiving portion  13 B fit together, the flange portion  11 B is fixed perpendicular to the plate member  10 . 
     The flange portion  21 A makes hinge movement around the coupling portion  24 A. The flange portion  21 A makes hinge movement toward the rear surfaces of the plate member  201  and the plate member  202 , and folds until reaching a position perpendicular to the plate member  201  and the plate member  202 . Then, when the flange portion  21 A is perpendicular to the plate member  201  and the plate member  202 , the flange fixing claw  25 A and the flange fixing claw receiving portion  23 A fit together. When the flange fixing claw  25 A and the flange fixing claw receiving portion  23 A fit together, the flange portion  21 A is fixed perpendicular to the plate member  201  and the plate member  202 . 
     The flange portion  31 B makes hinge movement around the coupling portion  34 B. The flange portion  31 B makes hinge movement toward the rear surface of the plate member  30  and folds until reaching a position perpendicular to the plate member  30 . Then, when the flange portion  31 B is perpendicular to the plate member  30 , the flange fixing claw  35 B and the flange fixing claw receiving portion  33 B fit together. When the flange fixing claw  35 B and the flange fixing claw receiving portion  33 B fit together, the flange portion  31 B is fixed perpendicular to the plate member  30 . 
     The folding and fixation of the flange portions  11 A to  31 A and  11 B to  31 B will be described later in detail. 
     The plate member  10  and the plate member  201  make hinge movement around the coupling portion  40  in a direction toward each other&#39;s rear surface, and fold until reaching a position perpendicular to each other. When the plate member  10  and the plate member  201  are perpendicular to each other, the claw receiving portion  16 A and the locking claw  27 A fit together, and the claw receiving portion  16 B and the locking claw  27 B fit together. When the claw receiving portion  16 A and the locking claw  27 A fit together and the claw receiving portion  16 B and the locking claw  27 B fit together, the plate member  10  and the plate member  201  are fixed perpendicular to each other. 
     The plate member  30  and the plate member  202  make hinge movement around the coupling portion  50  in a direction toward each other&#39;s rear surface, and fold until reaching a position perpendicular to each other. When the plate member  30  and the plate member  202  are perpendicular to each other, the claw receiving portion  26 A and the locking claw  37 A fit together, and the claw receiving portion  26 B and the locking claw  37 B fit together. When the claw receiving portion  26 A and the locking claw  37 A fit together and the claw receiving portion  26 B and the locking claw  37 B fit together, the plate member  30  and the plate member  202  are fixed perpendicular to each other. 
     The hinge movement and fixation of the plate members  10 ,  201 , and  202  will be described later in detail. 
     As illustrated in  FIG. 3 , the plate member  201  has guide grooves  211 A and  211 B and piece receiving portions  212 A and  212 B. 
     As illustrated in  FIG. 3 , the plate member  202  has rotation shafts  221 A and  221 B and coupling pieces  222 A and  222 B. The coupling piece  222 A is attached to the plate member  202  so as to be rotatable around the rotation shaft  221 A in a direction parallel to the plate surface of the plate member  202 . The coupling piece  222 B is attached to the plate member  202  so as to be rotatable around the rotation shaft  221 B in a direction parallel to the plate surface of the plate member  202 . 
     When coupling together the plate member  201  and the plate member  202 , the coupling piece  222 A rotates around the rotation shaft  221 A, moves along the guide groove  211 A, and fits between the piece receiving portion  212 A and the guide groove  211 A. When coupling together the plate member  201  and the plate member  202 , the coupling piece  222 B rotates around the rotation shaft  221 B, moves along the guide groove  211 B, and fits between the piece receiving portion  212 B and the guide groove  211 B. When the coupling piece  222 A fits between the piece receiving portion  212 A and the guide groove  211 A and the coupling piece  222 B fits between the piece receiving portion  212 B and the guide groove  211 B, the plate member  201  and the plate member  202  are coupled and fixed to each other. 
     Attachment and detachment of the plate member  201  and the plate member  202  will be described later in detail. 
     Next, referring to  FIGS. 4 ,  5 A, and  5 B, folding and fixation of the flange portions  11 A to  31 A and  11 B to  31 B will be described.  FIG. 4  is an upper view of the blank plate according to the first embodiment.  FIG. 5A  is a diagram for describing a state of the blank plate in which one flange portion is folded.  FIG. 5B  is a diagram for describing a state of the blank plate in which two flange portions are folded.  FIGS. 4 ,  5 A, and  5 B are diagrams of the blank plate as seen from the direction of arrow P in  FIG. 1 . For convenience of description,  FIG. 4  represents the coupling portions  24 A,  24 B,  34 A, and  34 B by dotted lines. 
     In the state of  FIG. 4 , the plate member  10 , the flange portion  11 A, and the flange portion  11 B are represented. As illustrated in  FIG. 4 , the flange portion  11 A has a distance L 1  from a side end thereof to the coupling portion  14 A. Similarly, the flange portion  11 B has a distance L 1  from a side end thereof to the coupling portion  14 B. The flange portion  21 A has a distance L 2  from a side end thereof to the coupling portion  24 A. Similarly, the flange portion  21 B has a distance L 2  from a side end thereof to the coupling portion  24 B. The flange portion  31 A has a distance L 3  from a side end thereof to the coupling portion  34 A. Similarly, the flange portion  31 B has a distance L 3  from a side end thereof to the coupling portion  34 B. The distances have the relationship L 1 &gt;L 2 &gt;L 3 . That is, the flange portions  11 A to  31 A are longitudinally folded at different positions. The flange portions  11 B to  31 B are folded at different positions. According to the folding positions of the flange portions  11 A to  31 A, the flange fixing claws  15 A to  35 A are also longitudinally arranged at different positions. According to the folding positions of the flange portions  11 B to  31 B, the flange fixing claws  15 B to  35 B are also longitudinally arranged at different positions. 
       FIG. 5A  illustrates the state in which the flange portions  11 A and  11 B in the state of  FIG. 4  make hinge movement and are perpendicular to the plate member  10 . In the state of  FIG. 5A , the flange fixing claw receiving portion  13 A (refer to  FIG. 3 ) of the flange portion  11 A fits to the flange fixing claw  15 A to fix the flange portion  11 A. In addition, the flange fixing claw receiving portion  13 B (refer to  FIG. 3 ) of the flange portion  11 B fits to the flange fixing claw  15 B to fix the flange portion  11 B. 
       FIG. 5B  illustrates the state in which the flange portions  21 A and  21 B in the state of  FIG. 5A  make hinge movement and are perpendicular to the plate member  201  and the plate member  202 . In the state of  FIG. 5B , the flange fixing claw receiving portion  23 A (refer to  FIG. 3 ) of the flange portion  21 A fits to the flange fixing claw  25 A to fix the flange portion  21 A. In addition, the flange fixing claw receiving portion  23 B (refer to  FIG. 3 ) of the flange portion  21 B fits to the flange fixing claw  25 B to fix the flange portion  21 B. 
     As illustrated in  FIG. 5B , the folded flange portion  11 A and flange portion  21 A are located at different positions in a long axis direction. In addition, the folded flange portion  11 B and flange portion  21 B are located at different positions in a long axis direction. Accordingly, even if, in the state of  FIG. 5B , the coupled plate member  201  and pate member  202  are folded toward the rear surface of the plate member  30  and the plate member  10  is folded toward the rear surface of the plate member  201 , the flange portion  11 A and the flange portion  21 A do not contact each other. In this case, the flange portion  11 A and the flange portion  21 A also do not contact each other. Therefore, when the flange portions  11 A,  11 B,  21 A, and  21 B are folded, the plate member  10  and the coupled plate member  201  and plate member  202  can be folded. 
     The flange portion  31 A is longitudinally folded at a position different from those of the flange portions  11 A and  21 A. In addition, the flange portion  31 A is longitudinally folded at a position different from those of the flange portions  11 A and  21 A. Therefore, the positional relationship between the flange portions  11 A and  11 B and the flange portions  31 A and  31 B, and the positional relationship between the flange portions  21 A and  21 B and the flange portions  31 A and  31 B are the same as the above-described positional relationship between the flange portions  11 A and  11 B and the flange portions  21 A and  21 B. Therefore, when any of the blank plates  1  to  3  has two folded flange portions, the plate members of the two folded flange portions of the blank plate can be folded. 
     In this arrangement, when the plate members are folded without folding the flange portions  11 A to  31 A and  11 B to  31 B, if an attempt is made to attach the blank plates in that state to the support column of the rack, portions of the folded blank plates to be coupled to the support column of the rack contact the support column of the rack. Thus, it is difficult for the blank plates with the plate members folded to be attached to the rack unless the flange portions  11 A to  31 A and  11 B to  31 B are folded. Accordingly, in the embodiment, the flange portions  11 A to  31 A and  11 B to  31 B are made foldable. 
     Next, referring to  FIGS. 6A to 6E , hinge movement and fixation of the plate members  10 ,  201 ,  202 , and  30  will be described.  FIG. 6A  is a cross section view of  FIG. 3  taken along line X-X.  FIG. 6B  is a diagram for describing the state in which the blank plate  1  is folded.  FIG. 6C  is a diagram for describing the state in which the blank plates  1  and  2  are folded.  FIG. 6D  is a diagram for describing the state in which the blank plate  3  is folded.  FIG. 6E  is a diagram for describing the state in which the blank plates  2  and  3  are folded. 
     Components illustrated in  FIG. 6A  are the same as those illustrated in  FIGS. 1 and 3  with the same reference signs. The right side as seen in  FIG. 6A  refers to the front side of the blank plate, and the left side as seen in  FIG. 6A  refers to the rear side of the blank plate. The coupling portions  40  and  50  have flat front surfaces and grooves on rear surfaces. However, the coupling portions  40  and  50  may have any other structure as far as the plate member  10  and the plate member  201  can make hinge movement toward rear sides thereof and the plate member  202  and the plate member  30  can make hinge movement toward rear sides thereof. In the state of  FIG. 6A , the blank plates  1  to  3  are fixed to the support columns of the rack. In the state of  FIG. 6A , there is no space open at the front side of the rack blocked by the blank plates  1  to  3 . 
       FIG. 6B  illustrates the state in which the plate member  10  in the state of  FIG. 6A  is folded. In the state of  FIG. 6B , the locking claw  27 A and the claw receiving portion  16 A fit together. In the case of  FIG. 6B , although not illustrated, the locking claw  27 B and the claw receiving portion  16 B (refer to  FIG. 3 ) also fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plate  1  without having to remove all the blank plates from the rack, as illustrated in  FIG. 6B . In this case, the blank plates  2  and  3  are fixed to the support columns of the rack. Thus, by folding the blank plate  1  as illustrated in  FIG. 6B , it is possible to place a housing  301  in the space of 1 U where the blank plate  1  previously existed, for example. 
       FIG. 6C  illustrates the state in which the coupled plate members  201  and  202  in the state of  FIG. 6B  are folded. In the state of  FIG. 6C , the locking claw  27 A and the claw receiving portion  16 A fit together and the locking claw  37 A and the claw receiving portion  26 A fit together. In the case of  FIG. 6C , although not illustrated, the locking claw  27 B and the claw receiving portion  16 B fit together and the locking claw  37 B and the claw receiving portion  26 B (refer to  FIG. 3 ) also fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plates  1  and  2  without having to remove all the blank plates from the rack, as illustrated in  FIG. 6C . In this case, the blank plate  3  is fixed to the support columns of the rack. Thus, by folding the blank plates  1  and  2  as illustrated in  FIG. 6C , it is possible to place a housing  302  in the space of 2 U where the blank plates  1  and  2  existed previously, for example. 
       FIG. 6D  illustrates the state in which the plate member  30  in the state of  FIG. 6A  is folded. In the state of  FIG. 6D , the locking claw  37 A and the claw receiving portion  26 A fit together. In the state of  FIG. 6D , although not illustrated, the locking claw  37 B and the claw receiving portion  26 B (refer to  FIG. 3 ) also fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plate  3 , without having to remove all the blank plates from the rack, as illustrated in  FIG. 6D . In this case, the blank plates  1  and  2  are fixed to the support columns of the rack. Thus, by folding the blank plate  3  as illustrated in  FIG. 6D , it is possible to place a housing  303  in the space of  1  U where the blank plate  3  previously existed, for example. 
       FIG. 6E  illustrates the state in which the coupled plate members  201  and  202  in the state of  FIG. 6D  are folded. In the state of  FIG. 6E , the locking claw  37 A and the claw receiving portion  26 A fit together and the locking claw  27 A and the claw receiving portion  16 A fit together. In the case of  FIG. 6E , although not illustrated, the locking claw  27 B and the claw receiving portion  16 B fit together and the locking claw  37 B and the claw receiving portion  26 B (refer to  FIG. 3 ) also fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plates  2  and  3  without having to remove all the blank plates from the rack, as illustrated in  FIG. 6E . In this case, the blank plate  1  is fixed to the support columns of the rack. Thus, by folding the blank plates  2  and  3  as illustrated in  FIG. 6E , it is possible to place a housing  304  in the space of 2 U where the blank plates  2  and  3  existed previously, for example. 
     As described in the foregoing, by folding each of the plate member  10 , the coupled plate members  202  and  201 , and the plate member  30  according to the position and size of a space to be opened, it is possible to mount the housing at a desired place without having to remove all the blank plates. 
       FIG. 7A  is a perspective view of the folded blank plates  1  and  2  as seen from above.  FIG. 7B  is a perspective view of the folded blank plates  1  and  2  as seen from below. 
       FIG. 7A  illustrates the state in which the flange portions  11 A,  11 B,  21 A, and  21 B are folded and the plate member  10  and the coupled plate members  201  and  202  are folded. 
     In the state of  FIG. 7A , the plate member  30  functions as a blank plate across the support columns of the rack, the plate member  30  is attached to the support columns of the rack through the attachment hole  32 A of the flange portion  31 A and through the attachment hole  32 B of the flange portion  31 B. In this case, the flange portions  11 B and  21 B are folded as illustrated in  FIG. 7A  and thus do not contact the support columns of the rack. In addition, as not illustrated in  FIG. 7A , the flange portions  11 A and  21 A (refer to  FIG. 1 ) also are folded and thus do not contact the support columns of the rack. Accordingly, it is possible to attach the blank plates to the rack such that only the plate member  30  is located at the front side of the rack. 
     In that case, as illustrated in  FIG. 7B , the blank plates are folded so that the flange portion  11 B and the flange portion  21 B do not contact and the flange portion  11 A and the flange portion  21 A do not contact. 
     Next, referring to  FIGS. 8 ,  9 A,  9 B,  10 A, and  10 B, attachment and detachment of the plate member  201  and the plate member  202  of the blank plate  2  will be described.  FIG. 8  is a cross section view of  FIG. 3  taken along line Y-Y.  FIG. 9A  is a diagram for describing the state of a coupling piece coupled to the blank plate  2 .  FIG. 9B  is a diagram for describing the state of the coupling piece separated from the blank plate  2 .  FIG. 10A  is a rear view of an upper blank plate with the blank plate  2  separated.  FIG. 10B  is a rear view of a lower blank plate with the blank plate  2  separated. 
     As illustrated in  FIG. 8 , the coupling piece  222 B is rotatably attached to a rear surface of the plate member  202  by the rotation shaft  221 B. In addition, the void piece receiving portion  212 B protrudes from the rear surface of the plate member  201 . Further, the guide groove  211 B is formed in the plate member  201  at a position opposed to the piece receiving portion  212 B. When the coupling piece  222 B is sandwiched and fit between the piece receiving portion  212 B and the guide groove  211 B, the plate member  201  is sandwiched between the guide groove  211 B and the plate member  202 . Accordingly, the plate member  201  and the plate member  202  are fixed in the coupled state. 
     As illustrated in  FIGS. 9A and 9B , the guide groove  211 B continues from the lower end portion of the plate member  201  to the inside of the piece receiving portion  212 B. As illustrated in  FIG. 9A , when the plate member  201  and the plate member  202  are coupled together, the coupling piece  222 B is stored in the piece receiving portion  212 B. When being stored in the piece receiving portion  212 B, the coupling piece  222 B can maintain coupling between the plate member  201  and the plate member  202  without coming off from the guide groove  211 B. Then, in the coupling state illustrated in  FIG. 9A , the coupling piece  222 B rotates along the guide groove  211 B around the rotation shaft  221 B.  FIG. 9B  illustrates the state in which the coupling piece  222 B rotates until coming off from the guide groove  211 B. In the state of  FIG. 9B , since the coupling piece  222 B comes off from the guide groove  211 B, the plate member  201  is no longer sandwiched between the coupling piece  222 B and the plate member  202 . Accordingly, the plate member  201  and the plate member  202  are uncoupled and the plate member  201  is detached from the plate member  202 . 
     As in the foregoing, the coupling piece  222 B, the guide groove  211 B, and the piece receiving portion  212 B are described. In addition, the coupling piece  222 A, the guide groove  211 A, and the piece receiving portion  212 A have the same structures as described above except that these components are arranged in bilateral symmetry with respect to the former components. 
     When the coupling piece  222 B enters the state of  FIG. 9B  and the coupling piece  222 A enters the state of  FIG. 9B , the blank plate is divided into the detached plate member  201  illustrated in  FIG. 10A  and the detached plate member  202  illustrated in  FIG. 10B . 
     When the plate member  201  and the plate member  202  are separated from each other, the plate member  10  has the claw receiving portions  16 A and  16 B, and the plate member  201  has the locking claws  27 A and  27 B, as illustrated in  FIG. 10A . Therefore, when the plate member  201  and the plate member  202  are separated from each other, the plate member  201  make hinge movement toward the rear surface of the plate member  10 , and then is fixed perpendicular to the plate member  10  by the claw receiving portions  16 A and  16 B and the locking claws  27 A and  27 B. 
     When the plate member  201  and the plate member  202  are separated from each other, the plate member  202  has the claw receiving portions  26 A and  26 B, and the plate member  30  has the locking claws  37 A and  37 B, as illustrated in  FIG. 10B . Therefore, when the plate member  201  and the plate member  202  are separated from each other, the plate member  202  make hinge movement toward the rear surface of the plate member  30 , and then is fixed perpendicular to the plate member  30  by the claw receiving portions  26 A and  26 B and the locking claws  37 A and  37 B. 
     That is, by separating the plate member  201  and the plate member  202  and fixing the same on the rear sides thereof, it is possible to open only the space at the position of the blank plate  2 . Accordingly, it is possible to mount a housing in the space at the position of the blank plate  2  without having to remove all the blank plates. 
     Next, referring to  FIG. 11 , descriptions will be given as to the state in which the blank plates according to the embodiment are attached to the rack.  FIG. 11  is a front view of the blank plates according to the first embodiment attached to the rack. 
     A blank plate  101  illustrated in  FIG. 11  is configured such that the blank plate with which the plate member  10  and the coupled plate members  201  and  202  folded as illustrated in  FIG. 6C  according to the embodiment is attached to a rack. In this case, the plate member  201  can block a space of 1 U at the front side of the rack. 
     A blank plate  102  illustrated in  FIG. 11  is configured such that the blank plate according to the embodiment in which the plate member  10  is folded as illustrated in  FIG. 6B  is attached to a rack. In this case, the blank plate  102  can block a space of 2 U at the front side of the rack. 
     A blank plate  103  illustrated in  FIG. 11  is configured such that the blank plate according to the embodiment not folded as illustrated in  FIG. 6A  is attached to a rack. In this case, the blank plate  103  can block a space of 3 U at the front side of the rack. 
     As described above, the length of shorter side of the blank plate according to the embodiment can be adjusted to any of sizes of 1 U to 3 U. Therefore, one blank plate can support any of spaces of 1 U to 3 U, which eliminates the need to prepare three kinds of blank plates for 1 U, 2 U, and 3 U and secure a storage space for the blank plates. 
     In addition, the blank plate according to the embodiment can be changed in the length of the shorter side while being attached to a rack. The blank plate according to the embodiment also makes it possible to open a space of 1 U at a middle portion thereof. Therefore, in either case of adding an electronic device or removing an electronic device, it is possible to eliminate the need for removing blank plates from the rack and selecting and attaching again new blank plates suited for a new space to the rack. That is, it is possible to save a person in charge of installing an electronic device from having to perform the excessive operations. Therefore, the blank plate according to the embodiment makes it easier to form a space suited to the position and size of a housing in which an electronic device is mounted, without needing a storage space for removed blank plates or spare blank plates. 
     In the embodiment, the blank plate  2  can be separated to open a space only at the position of the blank plate  2 . Alternatively, if it is not requested to form a space only at the position of the blank plate  2 , it is not requested that the blank plate  2  is configured to be separated. 
     [b] Second Embodiment 
     Next, blank plates according to a second embodiment will be described.  FIG. 12  is a rear view of the blank plates according to the second embodiment. The blank plates according to the embodiment are formed as blank plates for 5 U by sandwiching blank plates for coupling between the blank plates according to the first embodiment. 
     As illustrated in  FIG. 12 , the blank plates according to the embodiment include blank plates  401  to  405 . A plate member  421  and a plate member  422  of the blank plate  402  are attachable and detachable. In the following description, for the sake of convenience, the plate member  421  side of the blank plate  402  in which the plate member  421  and the plate member  422  are removed will be referred to as simply “plate member  421 ,” and the plate member  422  side of the same will be referred to as simply “plate member  422 .” A plate member  431  and a plate member  432  of the blank plate  403  are attachable and detachable. In the following description, for the sake of convenience, the plate member  431  side of the blank plate  403  in which the plate member  431  and the plate member  432  are removed will be referred to as simply “plate member  431 ,” and the plate member  432  side of the same will be referred to as simply “plate member  432 .” A plate member  441  and a plate member  442  of the blank plate  404  are attachable and detachable. In the following description, for the sake of convenience, the plate member  441  side of the blank plate  404  in which the plate member  441  and the plate member  442  are removed will be referred to as simply “plate member  441 ,” and the plate member  442  side of the same will be referred to as simply “plate member  442 .” 
     The structure formed by the blank plate  401  and the plate member  421  is the same as the structure formed by the blank plate  1  and the plate member  201  side of the blank plate  2  according to the first embodiment. The structure formed by the plate member  442  and the blank plate  405  is the same as the structure formed by the plate member  202  side of the blank plate  2  and the blank plate  3  according to the first embodiment. That is, except for the plate members  422 ,  431 ,  432 , and  441 , coupling the plate member  421  and the plate member  442  forms the same blank plate as the blank plate according to the first embodiment. 
     The plate member  422  and the plate member  431  form a blank plate for coupling. The plate member  432  and the plate member  441  form a blank plate for coupling. Specifically,  FIG. 12  illustrates a configuration in which the blank plate for coupling formed by the plate member  422  and the plate member  431  and the blank plate for coupling formed by the plate member  432  and the plate member  441  are sandwiched between the blank plates according to the first embodiment. 
     Next, referring to  FIG. 13 , the blank plate for coupling will be described.  FIG. 13  is a cross section view of  FIG. 12  taken along line Z-Z. 
     As illustrated in  FIG. 13 , the plate member  432  and the plate member  441  are coupled together by a coupling portion  450 . The coupling portion  450  can be formed by the same method as that for forming the coupling portion  40  and the coupling portion  50  described in relation to the first embodiment, for example. 
     The plate member  432  is provided with a coupling piece  433 . The coupling piece  433  is rotatably attached to the plate member  432  by a rotation shaft  434 . The plate member  432  is also provided with a claw receiving portion (not illustrated) that fits a locking claw  443  of a plate member  411  described later when the plate member  432  or the plate member  441  is folded toward the rear side. 
     The plate member  441  is also provided with a locking claw  443  on the rear side thereof. The plate member  441  is further provided with a claw receiving portion  444 . 
     When the plate member  432  or the plate member  441  is folded toward the rear side thereof, the claw receiving portion of the plate member  432  and the locking claw  443  of the plate member  411  fit together, whereby the plate member  432  and the plate member  441  are fixed to each other. 
     The plate member  432  and the plate member  441  are fixed together by the locking claw  443  using the same method as that for fixing the plate member  10  and the plate member  201  by the locking claw  27 A according to the first embodiment. 
     The plate member  431  and the plate member  432  are coupled together by the coupling piece  433  in the same manner as that for coupling the plate member  201  and the plate member  202  by the coupling piece  221 A according to the first embodiment, for example. The coupling of the plate member  431  and the plate member  432  is equivalent to the coupling of the blank plate for coupling and another blank plate for coupling. 
     As in the foregoing, the blank plate for coupling formed by the plate member  432  and the plate member  441  is described. The blank plate for coupling formed by the plate member  422  and the plate member  431  has the same structure as described above. 
     Referring to  FIG. 12 , the blank plate for coupling with the plate member  422  and the plate member  431  is coupled to the plate member  421  using the same method as that for coupling the plate member  431  and the plate member  432  illustrated in  FIG. 13 . In addition, referring to  FIG. 12 , the plate member  442  is coupled to the blank plate for coupling including the plate member  441  and the plate member  431  by using the same method as that for coupling the plate member  431  and the plate member  432  illustrated in  FIG. 13 . 
       FIG. 14A  is a diagram for describing the state in which the blank plates according to the second embodiment are not folded.  FIG. 14B  is a diagram for describing the state in which a housing is mounted at the position of the blank plate  401 .  FIG. 14C  is a diagram for describing the state in which a housing is mounted at the position of the blank plates  401  and  402 .  FIG. 14D  is a diagram for describing one example of the state in which a housing is mounted at the position of the blank plate  402 .  FIG. 14E  is a diagram for describing one example of the state in which a housing is mounted at the position of the blank plates  402  and  403 .  FIG. 14F  is a diagram for describing one example of the state in which a housing is mounted at the position of the blank plates  402  to  404 . 
     The right side as seen in  FIG. 14A  refers to the front side of the blank plates, and the left side as seen in  FIG. 14A  refers to the rear side of the blank plates. In the state of  FIG. 14A , the blank plates  401  to  405  are fixed to support columns of the rack. In the state of  FIG. 14A , none of the blank plates  401  to  405  is folded and thus there is no space open at the front side of the rack blocked with the blank plates  401  to  405 . 
       FIG. 14B  illustrates the state in which the blank plate  401  in the state of  FIG. 14A  is folded. In the state of  FIG. 14B , the locking claw of the blank plate  402  and the claw receiving portion of the blank plate  401  fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plate  401  without having to remove all the blank plates from the rack, as illustrated in  FIG. 14B . In this case, the blank plates  402  to  405  are fixed to the support columns of the rack. Accordingly, by folding the blank plate  401  as illustrated in  FIG. 14B , it is possible to mount a housing  501  in the space of 1 U where the blank plate  401  previously existed, for example. 
       FIG. 14C  illustrates the state in which the blank plate  402  in the state of  FIG. 14B  is folded. In the state of  FIG. 14C , the locking claw of the blank plate  402  and the claw receiving portion of the blank plate  401  fit together, and the locking claw of the blank plate  403  and the claw receiving portion of the blank plate  402  fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plates  401  and  402  without having to remove all the blank plates from the rack, as illustrated in  FIG. 14C . In this case, the blank plates  403  to  405  are fixed to the support columns of the rack. Accordingly, by folding the blank plates  401  and  402  as illustrated in  FIG. 14C , it is possible to mount a housing  502  in the space of 2 U where the blank plates  401  and  402  previously existed, for example. 
       FIG. 14D  illustrates the state in which, in the state of  FIG. 14A , the blank plate  402  is separated into the plate member  421  and the plate member  422  and the plate member  421  and the plate member  422  are folded. In the state of  FIG. 14D , the locking claw of the plate member  421  and the claw receiving portion of the blank plate  401  fit together. In addition, the locking claw of the blank plate  403  and the claw receiving portion of the plate member  422  fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plate  402  without having to remove all the blank plates from the rack, as illustrated in  FIG. 14D . In this case, the blank plates  401  and  403  to  405  are fixed to the support columns of the rack. Accordingly, by folding the plate members  421  and  422  as illustrated in  FIG. 14D , it is possible to mount a housing  503  in the space of 1 U where the blank plate  402  previously existed, for example. 
       FIG. 14E  illustrates the state in which the blank plate  403  in the state of  FIG. 14D  is folded. In the state of  FIG. 14E , the locking claw of the plate member  421  and the claw receiving portion of the blank plate  401  fit together, the locking claw of the blank plate  403  and the claw receiving portion of the plate member  422  fit together, and the locking claw of the blank plate  404  and the claw receiving portion of the blank plate  403  fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plates  402  and  403  without having to remove all the blank plates from the rack, as illustrated in  FIG. 14E . In this case, the blank plates  401 ,  404 , and  405  are fixed to the support columns of the rack. Accordingly, after the blank plate  2  is separated, by folding the plate members  421 , the blank member  422  and the blank plate  403  as illustrated in  FIG. 14E , it is possible to mount a housing  504  in the space of 2 U where the blank plates  402  and  403  previously existed, for example. 
       FIG. 14F  illustrates the state in which, in the state of  FIG. 14A , the blank plate  403  is separated into the plate member  431  and the plate member  432 , and the blank plate  402 , the plate member  431 , the plate member  432 , and the blank plate  404  are folded. In the state of  FIG. 14F , the locking claw of the blank plate  2  and the claw receiving portion of the blank plate  401  fit together, and the locking claw of the plate member  431  and the claw receiving portion of the blank plate  2  fit together. In addition, the locking claw of the blank plate  404  and the claw receiving portion of the plate member  432  fit together, and the locking claw of the blank plate  405  and the claw receiving portion of the blank plate  404  fit together. The blank plates according to the embodiment make it possible to form a space at the position of the blank plates  402  to  404  without having to remove all the blank plates from the rack, as illustrated in  FIG. 14F . In this case, the blank plates  401  and  405  are fixed to the support columns of the rack. Accordingly, after the blank plate  3  is separated, by folding the blank plate  402 , the plate member  431 , the plate member  432 , and the blank plate  404  as illustrated in  FIG. 14F , it is possible to mount a housing  505  in the space of 3 U where the blank plates  402  to  404  previously existed, for example. 
     The blank plates according to the embodiment make it possible to form a space of up to 3 U at any of the positions of the blank plates  401  to  405  in addition to the positions as described above. In addition, such a space can be formed using a plurality of methods, depending on the position of the space. For example, in  FIG. 14E , the blank plate  402  is separated to form a space at the position of the blank plates  402  and  403 . In addition, the blank plate  403  can be separated to form a space at the position of the blank plates  402  and  403 . 
     As described in the foregoing, the blank plates according to the embodiment make it possible to form a space of a desired size at a desired position in the place of 5 U. Accordingly, one blank plate can support spaces of various sizes. 
     In the embodiment, the blank plates for  5  U are used so that all of the blank plates can be folded even when any of the blank plates in the middle is separated. Alternatively, if up to two blank plates are to be made foldable, blank plates for coupling may be increased to form blank plates of a larger size suited to the front side of the largest rack. In addition, one blank plate for coupling may be used to form blank plates for 4 U. 
     In the embodiment, the blank plate is separated at one place. Alternatively, the blank plate may be separated at a plurality of places. For example, much more blank plates for coupling may be used to form blank plates for 10 U such that two blank plates for coupling in the middle can be separated to provide two spaces in the place of 10 U. 
     According to one embodiment of a blank plate disclosed in the subject application, there is provided an advantage that it is possible to form a space suited for the position and size of a housing to be mounted. 
     All examples and conditional language recited herein are intended for pedagogical purposes of aiding the reader in understanding the invention and the concepts contributed by the inventor to further the art, and are not to be construed as limitations to such specifically recited examples and conditions, nor does the organization of such examples in the specification relate to a showing of the superiority and inferiority of the invention. Although the embodiments of the present invention have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.