Abstract:
The present invention is directed to a folder type file tray assembled from a single paperboard blank. The file tray can be flattened to a reduced size during storage or transportation. It can also be assembled into different forms for different usage. The first form of file tray is an open-top box with a front opening for usage as a conventional file tray. The second form of file tray is an open-top box without a front opening, i.e., surrounded by four side walls for usage as a desk-top tool box. The third form of file tray is an open-top box with a foldable closing lid for usage such as a storage box. Additionally, the file tray of present invention can be stacked up directly to each other in multiple numbers without additional means of support. The file tray of present invention has low material and manufacturing costs. If needed, one side of paper blank can be laminated with higher quality paper or decorative material to enhance the appearance of file tray of present invention.

Description:
DESCRIPTION OF THE BACKGROUND 
   A file tray is commonly used for receiving, storing, sorting or organizing files, documents, mails, . . . etc. A simple file tray can be an open-top box made of metal, wood, plastic or paperboard. A disadvantage of such a file tray with a permanent structure is that it must occupy an equal space during usage and non-usage (ie., transportation or storage.) Another disadvantage is that it normally requires additional means of support to stack up to each other. 
   In some applications, multiple file trays are constructed within a structure, which is divided into a fixed number of rows and columns of trays by internal partitions. The disadvantage of such arrangement is that user can not alter the size of entire structure or the number of trays for usage. 
   The present invention is directed to a one piece, cut and scored paperboard blank so that it is ready to be folded into a folder type file tray. Therefore, it can be flattened to a reduced size during transportation and storage. The present invention is also directed to the structure of file tray so that individual file tray can be directly stacked up to each other without additional means of support. 
   Various styles and shapes of folder type paperboard boxes have been disclosed in the prior art for usage in packaging, food and beverage industries. For example, U.S. Pat. No. 5,839,649 disclosed a trapezoidal paper box with inner partitions made from a single paperboard blank. U.S. Pat. No. 5,183,200 disclosed a folder type paper box that can be assembled by bonding only one face in assembly. U.S. Pat. No. 4,109,786 disclosed a folder type paper box to hold round cylindrical articles in an angular position. U.S. Pat. No. 3,935,992 disclosed a folder type paper box with dual functions of a container and an open receptacle. U.S. Pat. No. 2,237,706 disclosed a display basket for toilet articles made from a single paperboard blank. However, none of prior art of folder type paper box can serve the unique purpose of the file tray of present invention. 
   SUMMARY OF THE INVENTION 
   The file tray of present invention is a folder type file tray made of a single paperboard blank. One object of present invention is to allow the file tray to be flattened to a reduced size during storage and transportation. Another object of present invention is to allow the file tray to be stacked up to each other without additional means of support when multiple trays are used. Another object of present invention is to allow the file tray to be assembled into different forms for different usage. For example, the first form of file tray is an open-top box with a front opening, or a conventional file tray where files are accessed through either top opening or front opening. The second form of file tray is an open-top box without a front opening, or an open container or storage box for usage such as a desk-top tool box The third form of file tray is an open-top box with a foldable closing lid, or a covered storage box. The appearance of file tray of present invention can be enhanced by laminating higher quality paper or decorative material on one side of paperboard blank. 

   
     BRIEF DESCRIPTION OF THE DRAWING 
       FIG. 1  is a top view of the first preferred embodiment of present invention, a one-piece foldable paper blank cut and scored so that it can be folded into a file tray as shown in FIG.  4 . 
       FIG. 2  is a top view of the second preferred embodiment of present invention, a one-piece foldable paper blank cut and scored so that it can be folded into multiple forms as shown in  FIG. 5 , FIG.  6  and FIG.  7 . 
       FIG. 3  is a top view of the third preferred embodiment of present invention, a one-piece foldable paper blank cut and scored so that it can be folded into a file tray as shown in FIG.  8 . 
       FIG. 4  is a perspective view of file tray assembled from the first preferred embodiment of present invention shown in  FIG. 1. , in which the bottom tray consists of double layers of paperboards. 
       FIG. 5  is a perspective view of the first form of file tray assembled from the second preferred embodiment of present invention shown in  FIG. 2 , in which the bottom tray consists of double layers of paperboards. 
       FIG. 6  is a perspective view of the second form of file tray assembled from the second preferred embodiment of present invention shown in  FIG. 2 , in which the bottom tray consists of double layers of paperboards, and is surrounded by four side walls. 
       FIG. 7  is a perspective view of the third form of file tray assembled from the second preferred embodiment of present invention shown in  FIG. 2 , in which a single layer of bottom tray is extended for use as a foldable cover. 
       FIG. 8  is a perspective view of file tray assembled from the third preferred embodiment of present invention, having a single layer of paperboard at the bottom of tray. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  represents the one-piece foldable paper blank of the first preferred embodiment of present invention. The U-shape top panel  101  consists of three legs: left leg, back leg and right leg. Top panel  101  has five outer sides  1011  through  1015 , and three inner sides  1016  through  1018 . With exception of inner side  1017 , all outer and inner sides of top panel  101  are scored as fold lines as follows: the outer side wall panel  102  of the right leg being extended from top panel  101  with a fold line  1011 ; the inner side wall panel  103  of the right leg being extended from top panel  101  with a fold line  1016 ; the outer side wall panel  104  of the left leg being extended from top panel  101  with a fold line  1013 ; the inner side wall panel  105  of the lef leg being extended from top panel  101  with a fold line  1018 ; the back wall panel  106  of the back leg being extended from top panel  101  with a fold line  1012 ; the first closing flap  107  of right leg being extended from top panel  101  with a fold line  1015 ; the first closing flap  108  of left leg being extended from top panel  101  with a fold line  1014 . 
   The front wall panel  109  of the right leg is extended from side wall panel  102  with a fold line  1019 . The front wall panel  110  of the left leg is extended from side wall panel  104  with a fold line  1020 . The second closing flap  111  of right leg is extended from side wall panel  103  with a fold line  1021 . The second closing flap  112  of left leg is extended from side wall panel  105  with a fold line  1022 . The closing flap  111  has two tabs  113  and  114  for engaging into holes  117  and  118  respectively during assembling. The closing flap  112  has two tabs  115  and  116  for engaging into holes  119  and  120  respectively during assembling. The third closing flap  121  of left leg is extended from side wall panel  104  with a fold line  1023 . The bottom surface of closing flap  121  is applied with glue. The third closing flap  122  of right leg is extended from front wall panel  109  of right leg with a fold line  1024 . The fourth closing flap  123  of left leg is extended from front wall panel  110  of left leg with a fold line  1025 . The first and second closing flaps  124  and  125  of back leg are extended from the outside wall panel  106  of back leg with a fold line  1026  and  1027  respectively. 
   The first bottom panel  126  is extended from side wall  102  with a fold line  1028 . The second bottom panel  127  is extended from the first bottom panel  126  with a fold line  1029 . The second bottom panel  127  is folded over the top of the first bottom panel  126  during assembling. The front wall panel  128  of back leg is extended from bottom panel  127  with a fold line  1030 . The third closing flap  129  of back leg is extended from wall panel  128  with a fold line  1031 . The fifth closing flap  130  of left leg is extended from bottom panel  126  with a fold line  1032 . The fourth closing flap  131  of right leg is extended from bottom panel  126  with a fold line  1033 . 
     FIG. 2  represents the one-piece foldable paper blank of the second preferred embodiment of present invention. The U-shape top panel  201  consists of three legs: left leg, back leg and right leg. Top panel  201  has five outer sides  2011  through  2015 , and three inner sides  2016  through  2018 . With exception of inner side  2017 , all outer and inner sides of top panel  201  are scored as fold lines as follows: the outer side wall panel  202  of the right leg being extended from top panel  201  with a fold line  2011 ; the inner side wall panel  203  of the right leg being extended from top panel  201  with a fold line  2016 ; the outer side wall panel  204  of the left leg being extended from top panel  201  with a fold line  2013 ; the inner side wall panel  205  of the left leg being extended from top panel  201  with a fold line  2018 ; the back wall panel  206  of the back leg being extended from top panel  201  with a fold line  2012 ; the first closing flap  207  of right leg being extended from top panel  201  with a fold line  2015 ; the first closing flap  208  of left leg being extended from top panel  201  with a fold line  2014 . 
   The front wall panel  209  of the right leg is extended from side wall panel  202  with a fold line  2019 . The front wall panel  210  of the left leg is extended from side wall panel  204  with a fold line  2020 . The second closing flap  211  of right leg is extended from side wall panel  203  with a fold line  2021 . The second closing flap  212  of left leg is extended from side wall panel  205  with a fold line  2022 . The closing flap  211  has two tabs  213  and  214  for engaging into holes  217  and  218  respectively during assembling. The closing flap  212  has two tabs  215  and  216  for engaging into holes  219  and  220  respectively during assembling. The third closing flap  221  of left leg is extended from side wall panel  204  with a fold line  2023 . The bottom surface of closing flap  221  is applied with glue. The third closing flap  222  of right leg is extended from front wall panel  209  of right leg with a fold line  2024 . The fourth closing flap  223  of left leg is extended from front wall panel  210  of left leg with a fold line  2025 . The first and second closing flaps  224  and  225  of back leg are extended from the outside wall panel  206  of back leg with a fold line  2026  and  2027  respectively. 
   The first bottom panel  226  is extended from side wall  202  with a fold line  2028 . Panel  227  is extended from the first bottom panel  226  with a fold line  2029 . Panel  228  is extended from the panel  227  with a fold line  2030 . Panel  229  is extended from the panel  228  with a fold line  2031 . Panel  230  is extended from the panel  229  with a fold line  2032 . Panel  231  is extended from the panel  230  with a fold line  2033 . Panel  232  is extended from the panel  231  with a fold line  2034 . Panel  233  is extended from the panel  232  with a fold line  2035 . The fifth closing flap  234  of left leg is extended from bottom panel  226  with a fold line  2036 . The fourth closing flap  235  of right leg is extended from bottom panel  226  with a fold line  2037 . 
   Panels  227  through  233  are properly sized so that they can be folded to create three different forms of a file tray as shown in  FIG. 5 , FIG.  6  and FIG.  7 . 
   To create a file tray in the form as shown in  FIG. 5 , Panels  227  through  233  are folded as follows: Panels  227 ,  228  and  229  are integrated into a single panel as a second bottom panel, which is folded along fold line  2029  and over the top of first bottom panel  226 . Panel  230  is folded along fold line  2032  vertically to serve as a front wall of back leg. Panels  231 ,  232  and  233  are folded along fold lines  2033 ,  2034  and  2035  respectively to serve as the third, forth and fifth closing flap of back leg respectively. 
   To create a file tray in the form as shown in  FIG. 6 , Panels  227  through  233  are folded as follows: Panel  227  is folded upward along fold line  2029  to serve as a front panel of front wall. Panel  228  is folded downward along fold line  2030  to serve as a back panel of front wall. Panels  229 ,  230  and  231  are integrated into a single panel as a second bottom panel, which is folded over the top of first bottom panel  226 . Panel  232  is folded upward along fold-line  2034  to serve as a front wall of back leg. Panel  233  is folded along fold line  2035  to serve as the third closing flap of back leg. 
   To create a file tray in the form as shown in  FIG. 7 , Panels  227  through  233  are folded as follows: Panel  227  is folded upward along fold line  2029  to serve as a front panel of closing lid. Panels  228  through  231  are integrated into a single panel as a top panel of closing lid, which is folded over the top of back leg along fold line  2030 . Panel  232  is folded downward along fold line  2034  to serve as a second back wall of back leg. Panel  233  is folded along fold line  2035  to serve as a third closing flap of back leg. 
     FIG. 3  represents the one-piece foldable paper blank of the third preferred embodiment of present invention. The U-shape top panel  301  consists of three legs: left leg, back leg and right leg. Top panel  301  has five outer sides  3011  through  3015 , and three inner sides  3016  through  3018 . With exception of inner side  3017 , all outer and inner sides of top panel  301  are scored as fold lines as follows: the outer side wall panel  302  of the right leg being extended from top panel  301  with a fold line  3011 ; the inner side wall panel  303  of the right leg being extended from top panel  301  with a fold line  3016 ; the outer side wall panel  304  of the left leg being extended from top panel  301  with a fold line  3013 ; the inner side wall panel  305  of the left leg being extended from top panel  301  with a fold line  3018 ; the first back wall panel  306  of the back leg being extended from top panel  301  with a fold line  3012 ; the first closing flap  307  of right leg being extended from top panel  301  with a fold line  3015 ; the first closing flap  308  of left leg being extended from top panel  301  with a fold line  3014 . 
   The front wall panel  309  of the right leg is extended from side wall panel  302  with a fold line  3019 . The front wall panel  310  of the left leg is extended from side wall panel  304  with a fold line  3020 . The second closing flap  311  of right leg is extended from side wall panel  303  with a fold line  3021 . The second closing flap  312  of left leg is extended from side wall panel  305  with a fold line  3022 . The closing flap  311  has two tabs  313  and  314  for engaging into holes  317  and  318  respectively during assembling. The closing flap  312  has two tabs  315  and  316  for engaging into holes  319  and  320  respectively during assembling. The third closing flap  321  of left leg is extended from side wall panel  304  with a fold line  3023 . The bottom surface of closing flap  321  is applied with glue. The third closing flap  322  of right leg is extended from front wall panel  309  of right leg with a fold line  3024 . The fourth closing flap  323  of left leg is extended from front wall panel  310  of left leg with a fold line  3025 . The first and second closing flaps  324  and  325  of back leg are extended from the first back wall panel  306  of back leg with a fold line  3026  and  3027  respectively. 
   The bottom panel  326  is extended from side wall  302  with a fold line  3028 . The second back wall panel  327  of back leg is extended from bottom panel  326  with a fold line  3030 . The second top panel  328  of back leg is extended from panel  327  with a fold line  3031 . The front wall panel  329  of back leg is extended from panel  328  with a fold line  3032 . The front wall panel  329  of back leg has two holes  332  and  333  for engaging tabs  331  and  330  respectively. The fifth closing flap  334  of left leg is extended from bottom panel  326  with a fold line  3033 . The fourth closing flap  335  of right leg is extended from bottom panel  326  with a fold line  3034 . 
     FIG. 4  is a perspective view of a file tray in the final form folded and assembled from the first preferred embodiment of paper blank of the invention. Such a file tray is in the form of an open-top box with a front opening. Each panel number as shown in  FIG. 4  corresponds to that of the first preferred embodiment of paper blank as shown in FIG.  1 . 
     FIG. 5  is a perspective view of the first form of a file tray folded and assembled from the second preferred embodiment of paper blank of the invention. Such a file tray is in the form of an open-top box with a front opening, which is identical to that of FIG.  4 . Each panel number as shown in  FIG. 5  corresponds to that of the second preferred embodiment of paper blank as shown in FIG.  2 . 
     FIG. 6  is a perspective view of the second form of a file tray folded and assembled from the second preferred embodiment of paper blank of the invention. Such a file tray is in the form of an open-top box with a front wall Each panel number as shown in  FIG. 6  corresponds to that of the second preferred embodiment of paper blank as shown in FIG.  2 . 
     FIG. 7  is a perspective view of the third form of a file tray folded and assembled from the second preferred embodiment of paper blank of the invention. Such a file tray is in the form of a closing-top box with a foldable closing lid. Each panel number as shown in  FIG. 7  corresponds to that of the second preferred embodiment of paper blank as shown in FIG.  2 . 
     FIG. 8  is a perspective view of a file tray in the final form folded and assembled from the third preferred embodiment of paper blank of the invention. Such a file tray is in the form of an open-top box with a front opening, which is similar but not identical to that of  FIG. 4  or FIG.  5 . The file tray of  FIG. 8  has a single bottom panel, but the file tray of  FIG. 4  or  FIG. 5  has double bottom panels. The selection of a file tray with a single bottom panel or double bottom panels may depend on the material strength and thickness of paper blank. When one side of paper blank is laminated with decorative material for enhancing the appearance of file tray, a file tray of double bottom panels is more desirable so that only the decorative side of paper blank is visible (ie., the top surface of bottom panel).