PATENT ABSTRACT
A plastic tote box of the type having a lid. The lid is a two-piece hinged lid, with each piece of the lid being hinged along the top of opposite sides of the box. Each of the lid pieces has at least one hollow channel formed therein. The hollow channels improve the structural integrity of the lid pieces without adding additional lid material. In a box top lid having a substantially planar central area surrounded by a raised peripheral edge, a cut out is formed in the peripheral edge providing a drainage path for fluid which has collected in the central area to flow off the lid without entering the box. A mail slot is formed in a box side for insertion of a packing slip or the like into the box without opening the box lid.

PATENT DESCRIPTION
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application No. 60/112,876 filed Dec. 18, 1998, and is a continuation of U.S. patent application Ser. No. 09/460,154 filed on Dec. 13, 1999. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not Applicable. 
     FIELD OF THE INVENTION 
     This invention relates to improvements in plastic tote boxes, and in particular to a tote box having improved structural integrity, drainage, and security. 
     BACKGROUND OF THE INVENTION 
     Plastic tote boxes have been known for a number of years and have found widespread usage in commercial and residential applications. Such boxes have been available having no lids, with one-piece lids which enclose the entire top of the box, or with two-piece lids, each piece of which is hinged along one side of the tote box and in which the pieces meet along a line of closure generally in the middle of the box top. These boxes are used for storing and transporting parts or other items and are reusable. The boxes and their lids are also typically made of plastic materials which are recyclable. 
     Plastic tote boxes having two piece lids are particularly troublesome when a heavy object is placed on the lid. The heavy object may cause the box sides to flex outward, separating the two piece lid and allowing the object to fall into the box. The two piece lid then snaps back into place with the object inside the box and no indication of its location. If the object is taller than the box, the object falls to the box bottom and is trapped by the box lid pieces impinging on the object sides, making removal of the object from the box difficult. 
     During shipment and storage, boxes of the type described, individually and in stacks, are also subjected to moisture, such as rain, condensation, accidental or intentional spraying, or leakage from an upper box to a lower box. If this moisture is permitted to enter the box, it can sometimes damage or ruin the items contained in the box. It is, therefore, desirable that moisture collected on the box lid be directed away from the interior of the box. 
     Tote boxes of the type described are also often secured by strapping a band around the box exterior to keep the box sides from flexing outward and the lid from inadvertently opening. The band tends to dig into the box edges causing then to crack and fail. If the box is strapped over lid hinges, the hinges can be crushed by the tightened strap rendering the hinge inoperable. 
     Furthermore, packing slips are often required in a box for shipment. The packing slip is often available only after the box has been closed and stacked. This makes insertion of the slip into the box very difficult. Currently, in order to insert a packing slip in a closed stacked box, the box stack must be disassembled to the desired box and the box must be opened to insert the slip into the box. 
     SUMMARY OF THE INVENTION 
     The invention provides improvements in a plastic tote box of the type having a two-piece hinged lid, with each piece of the lid being hinged along the top of opposite sides of the box. In a box incorporating the invention, each of the lid pieces has at least one channel which is closed for 360° in a plane perpendicular to a longitudinal axis of the channel and formed in at least one of the lid sections to increase the strength of each lid section. The channel overlaps the other lid section when the lid is closed. 
     In another aspect of the invention, a hollow channel in each lid piece overlaps the other lid piece, further increasing the structural integrity of the closed lid. 
     In another aspect of the invention, a plastic tote box of the type which is provided with a lid having a substantially planar central area surrounded by a raised peripheral edge has a cut out formed in the peripheral edge, providing a planar surface extending through the peripheral edge. The planar surface provides a path for fluid which has collected in the central area to flow off the lid without entering the box. 
     In another aspect of the invention, a plastic tote box of the type which is provided with four generally vertical sides and a lid for covering an open top of the box has at least one of the box sides with a mail slot formed in it. The mail slot allows insertion of a packing slip or the like into the box without opening the box lid. 
     Other objects and advantages of the invention will be apparent from the drawings and detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a tote box incorporating the invention; 
     FIG. 2 is a cross sectional view of FIG. 1 along line  2 — 2 ; 
     FIG. 3 is a cross sectional view of FIG. 1 along line  3 — 3 ; 
     FIG. 4 is a perspective view of FIG. 1 with the lid open; 
     FIG. 5 is a cross sectional view of FIG. 4 along line  5 — 5 ; 
     FIG. 6 is a cross sectional view of FIG. 4 along line  6 — 6 ; 
     FIG. 7 is a top perspective view of the lid piece of FIG. 1; and 
     FIG. 8 is a plan view of the underside of the lid piece of FIG.  1 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIGS. 1 and 4 illustrate a tote box  10  of the present invention. The tote box  10  is molded plastic, for example polypropylene, and has a bottom  12 , longitudinally extending sides  14 ,  16 , and laterally extending end walls  18 ,  20 . At the top of the side  14 ,  16  and end  18 ,  20  walls, a rim  22  encircles the top of the box  10 . A lid  24  is formed from two pieces  26 ,  28  hinged along the top of adjacent respective sidewalls  14  or  16 . 
     As is conventional, all of the walls  14 ,  16 ,  18 , and  20  taper outwardly at a certain draft angle from the bottom  12  up so that one box  10  can be nested inside another box  10  with the lid open. Alternatively, the boxes  10  can be stacked by placing one box  10  on the closed lid  24  of another box  10 . 
     It is also noted that at the midpoints of the end walls  18  and  20 , a handle  30  which conforms arcuately to the fingers of a person carrying the box  10  using both hands on the ends  18 ,  20  is formed. The handles  30  are best shown in FIGS. 1,  2 , and  4 . Nesting stops  32  are provided on each side of each handle  30 , which rest against the rim  22  of the lower box  10  when nesting the boxes  10 . 
     Referring particularly to FIGS. 1 and 2, a mail slot  34  disposed above the handle  30  is formed in the end wall  18 . The mail slot  34  provides an opening into the box  10  for a packing slip or the like. Thus, the packing slip can be inserted into the box  10  without opening the box lid  24 . This is particularly advantageous when the box lid  24  is locked or the box  10  is part of a box stack. 
     As shown in FIGS. 1 and 4, the lid  24  is formed from two identical pieces  26 ,  28  hinged along the top of the adjacent respective side wall  14  or  16 , and has a top side  36  and an underside  38 . The lid top side  36  is a substantially central planar surface  40  surrounded by a raised peripheral edge. The peripheral edge is formed as an integral part of the pieces  26  and is defined by raised longitudinal edges  42  along the top of each box sidewall  14 ,  16  joined by raised end lips  44  which wrap over the rim  22  above the box end walls  18 ,  20 . The raised edges  42  and lips  44  prevent a box  10  stacked on the central planar surface  40  from slipping off of the closed lid  24 , and block drainage from flowing over them. 
     As shown in FIGS. 1 and 3, cut outs  47  formed in each raised longitudinal edge  42  provide a planar surface  48  which extends from the central planar surface  40  through the raised edge  42  and hinged connections  50 . The planar surface  48  provides a pathway for water or other fluid which may collect in the central planar surface  40  to flow off the box lid  24 . Preferably, the cut outs  47  are sized to receive bands  52  (shown in phantom in FIGS. 1 and 3) for strapping the box  10  closed. 
     Looking particularly at FIG. 3, the planar surface  48  extends through the hinged connection  50  to the outer edge of the rim  22  to ensure the fluid does not enter the box interior through the hinged connection  50 . Gussets  54  disposed beneath the planar surface  48  are formed as an integral part of the rim  22  and box side  14 . The gussets  54  strengthen the rim  22  at the strapping location reducing the potential of rim  22  failure when the box  10  is tightly strapped using bands  52 . 
     Preferably, the hinge connection  50  is a piano-type hinge such as disclosed in U.S. Pat. No. 5,860,527, which is commonly owned with the present invention and hereby incorporated herein by reference. The piano-type hinge  50  is substantially identical to that disclosed in U.S. Pat. No. 5,860,527, except that the planar surface  48  extends through the hinge connection defining two hinge sections  56 ,  58  on each side of the planar surface  48 . 
     Referring back to FIGS. 1 and 4, the two lid pieces  26 ,  28  are molded plastic, e.g., polypropylene, and are substantially identical to one another. Preferably, the lid pieces  26 ,  28  are formed using a molding method which forms hollow channels in the plastic material, such as injection molding techniques described in U.S. Pat. Nos. 4,498,860; 4,740,150; 4,923,666; 4,923,667; and 5,770,237, which are hereby incorporated by reference. Other methods known in the art to form hollow channels may be used, such as inserting pins in the plastic material or the like, without departing from the scope of the present invention. 
     Each piece  26 ,  28  meets with the other piece in the middle of the box  10  along a substantially straight longitudinal line of closure  60  on the lid underside  38 . The lid pieces  26 ,  28  are substantially identical and are locked together along the line of closure  60  with engagement structures of any suitable construction. For example, one possible construction is as disclosed in U.S. Pat. No. 4,432,467, which is commonly owned with the present invention and is hereby incorporated by reference. 
     Looking particularly at FIGS. 4 and 8, each lid piece  26 ,  28  has rib structures on its underside forming an irregular grid. The grid is defined by longitudinal ribs  62  extending from one lid end lip  44  or  46  toward the other and lateral ribs  64  extending from the hinged connection  50  toward the underside line of closure  60 . The rib structures represented by the longitudinal ribs  62  and lateral ribs  64  strengthen the lid pieces  26 ,  28 . 
     Referring back to FIGS. 1,  4 , and  7 , as is common and known from U.S. Pat. No. 4,432,467, each piece  26 ,  28  has an overlapping flap  66  which extends beyond the line of closure  60  to a flap edge  72  and an underlapping shelf  68  which extends from a shelf base  73  to the line of closure  60 . The overlapping flap  66  and underlapping shelf  68  of each piece  26 ,  28  define a line of closure  70  on the lid top side  36  along the shelf base  73  and flap edge  72  which are joined by a diagonal line of closure  74 . 
     As shown in FIGS. 7 and 8, each flap  66  has rib structures on its underside similar to those disclosed in U.S. Pat. No. 5,860,527, except since eight inverted box-like engaging structures  76 , are provided on the shelf  68 , the lateral ribs  78  and a longitudinal rib  80  on the flap underside are spaced and provided in number so as to receive the eight structures  76  including a centrally located double lateral rib  82  and a double rib  84  along the diagonal line of closure  74 . 
     In addition to the lid rib structures, hollow structural channels, shown by dashed lines in FIGS. 1 and 8, in each lid piece  26 ,  28  increase the lid  24  structural integrity without adding additional material. A first hollow channel  86  extends from the lid piece lip  44  adjacent the flap  66  along the underside line of closure  60  toward the diagonal line of closure  74 . The channel  86  then extends inward along the diagonal line of closure  74  to the shelf base  73 , and then along the shelf base  73  toward the opposing lid end lip  46  adjacent the shelf  68 . The first hollow channel  86  strengthens the lid  24  against bending about a lateral axis when a load is placed on the lid top side  36 . 
     Lateral hollow structural channels  88  in each lid piece  26 ,  28  extend along selected lateral ribs  64  from the first hollow structural channel  86  toward the hinged connection  50  to strengthen the lid piece from bending about a longitudinal axis. At each end of the first hollow channel  86 , lateral hollow channels  90  are formed in the inner wall  92  of the end lips  44 ,  46  to further strengthen the lid  24  and prevent the lips  44 ,  46  from rolling in and slipping off the end tops. 
     Flap hollow structural channels  94  also extend toward the flap edge  72  along the top line of closure diagonal  74 , and between the centrally located double lateral ribs  82 . These hollow structural channels  94  extend from, and are formed with, the first hollow structural channel  86 . The flap hollow channels  94  strengthen the flap  66  which has a tendency to bend upward when a load is placed on the closed lid  24 . Thus, the hollow channels  94  in the flap  66  prevent the lid  24  from opening inward under a load and allowing the load to fall into the box  10 . 
     Closing the two substantially identical lid pieces  26 ,  28 , having hollow channels  86 ,  94  along the line of closure  60 ,  73 , provides a lid  24  with an improved load bearing capacity. The closed lid pieces  26 ,  28  provide parallel hollow channels on both sides of the line of closure  60  along the lateral center of the closed lid  24 , and along a portion of the diagonal line of closure  74  in the lid center. Advantageously, when the lid  24  is closed, the flap hollow structural channels  94  in each lid piece  26 ,  28  overlap the shelf  68  of the other piece  26 ,  28  along the diagonal line of closure  74  in the center of the lid  24 . The hollow channels  86 ,  94  resist lid bending at the lid line of closures  60 ,  74  further strengthening the structural integrity of the closed lid  24 . 
     Preferred embodiments of the invention have been described in considerable detail. Many modifications and variations of the preferred embodiments described will be apparent to those skilled in the art which incorporate the invention. Therefore, the invention should not be limited to the embodiments described, but should be defined by the claims which follow.