Abstract:
A box comprising a bottom, a pair of side walls, and a pair of end walls is stackable due to the shape of the end walls and their interaction with the bottom of the box. The end walls include parallel, upwardly directed arches flanked by flat surfaces which prevent lateral relative movement of stacked boxes. Notching the bottom to receive the end walls such that they grip the bottom prevents longitudinal relative movement of the stacked boxes.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of The Invention 
     This invention relates to stackable boxes designed to be simple in construction, inexpensive to manufacture, and yet allow ease of stacking in a stable configuration. 
     2. Description of Related Art 
     Boxes have been designed to be stackable for some time, arising from the necessity of storing or transporting a large number of boxes in a small space. A few representative examples follow: 
     McLean, U.S. Pat. No. 1,809,523, discloses a foldable, open top, stackable container. Hinged side walls and end walls are held in their open state by means of biasing springs  18  and leaf springs  17 . In order to constrain McLean&#39;s stacked boxes against longitudinal and lateral slippage, the end walls are provided with mating tabs  19  and notches (unnumbered); the edges of the tabs of the bottom box abut the edges of the notches of the top box to prevent lateral relative movement. Shoulders  20  on the ends of the box&#39;s floor  10  abut the inner surface of bottom box&#39;s tabs  19  to prevent longitudinal sliding of the top box on the bottom box. McLean&#39;s box is complex, unstable in construction, lacks aesthetic appeal, and the interlocking structure has sharp edges which are subject to damage to themselves and others. 
     Cranston, U.S. Pat. No. 2,501,379, discloses a stackable display tray in which a recessed peripheral edge around the bottom of the tray fits within a complementary recessed lip interior of an identical tray&#39;s top peripheral edge. A lattice-work insert is shaped to fit within the tray&#39;s interior. Cranston&#39;s tray is inefficient inasmuch as the complementary recesses take up a large proportion of the interior volume of the tray, limiting its usefulness. 
     Voorhis, U.S. Pat. No. Des. 124,755, shows a design for stackable soap bar&#39;s having complementary, upwardly extending arches on the top and bottom surfaces, so that the convex arch of the top of the lower bar mates with the concave bottom of the upper bar. Voorhis&#39;s bars are not stable, inasmuch as there are no means provided for preventing the arcuate surfaces from sliding laterally relative to each other. 
     Ruff, U.S. Pat. No. 2,777,597, discloses a stackable tote box having a channel-shaped base whose end edges are welded to an end supporting member  14  which in turn is welded exteriorly thereof to end member  16  in a stepped relationship. End supporting member  14  is of an inverted V-shape; end member  16  includes parallel, V-shaped arches forming a convex peak opposite a concave notch. When stacked, the V-shaped notch of the top box mates with the V-shaped peak of the bottom box to support the top box and to prevent lateral relative movement of the boxes. The inside surfaces of the bottom box&#39;s end members  16  abut the outside surfaces of support members  14  of the top box to prevent longitudinal relative movement of the boxes. The box of Ruff is deficient in that it requires many pieces and a labor intensive assembly. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     The present invention overcomes the difficulties described above by providing an aesthetically pleasing box have few parts, easy assembly, and a stable configuration when stacked on an identical box. 
     The present invention accomplishes the above by providing a box comprising a bottom, two side walls, and two end walls joined together by placing the bottom in a recessed groove in the side and end walls and affixing the corners of adjacent walls together. The end walls are shaped to mate easily and securely when stacked. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, aspects, uses, and advantages of the present invention will be more fully appreciated as the same becomes better understood from the following detailed description of the present invention when viewed in conjunction with the accompanying drawings, in which: 
     FIG. 1 is a perspective view which illustrates a preferred embodiment of the present invention; 
     FIG. 2 is a top view of the invention of FIG. 1; 
     FIG. 3 is a bottom view of the invention of FIG. 1; 
     FIG. 4 is an end view of the invention of FIG. 1; 
     FIG. 5 is a side view of the invention of FIG. 1; 
     FIG. 6 is a perspective view of two of the boxes (shown in FIG. 1) stacked one on top of the other; 
     FIG. 7 illustrates a use of the present invention after receiving an insert into the interior of the inventive box; 
     FIG. 8 shows a second embodiment of the invention; and 
     FIG. 9 shows a third embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A stackable container or stackable box  10  is shown in perspective in FIG.  1 . Box  10  comprises a bottom  12 , a pair of side walls  14 , and a pair of end walls  16 . Because of the longitudinal and transverse symmetry of box  10 , side walls  14  are identical to each other and end walls  16  are identical to each other. 
     Referring to FIGS. 1,  4 , and  5 , side walls  14  and end walls  16  are preferably joined together by box joints  18 , although any means known in the art for effectively securing them is sufficient. 
     Side walls  14  (FIG. 5) are preferably rectangularly shaped with a horizontal upper edge  20  parallel with a horizontal lower edge  22  joined to vertical end edges  24  at square corners  26 . The particular dimensions of side walls  14  are selected dependent on the end use of box  10 . For example, the organizer tray of FIG. 7 has side walls of approximately 286×41 mm; the pencil box of FIG. 8 has side walls of approximately 119×85 mm; and the file box of FIG. 9 has side walls of approximately 354×270 mm. 
     End walls  16  (FIG. 4) comprise opposed, linear, vertical edges  28 , a top edge  30 , and a bottom edge  32 . Top edge  30  includes a pair of flats  34  extending inwardly from vertical ends  28  and an upwardly directed arcuate arch  36  joined at each end to one of flats  34 . Bottom edge  32  includes a pair of flats  38  extending inwardly from vertical ends  28  and an upwardly directed arcuate arch  40  joined at each end to one of flats  38 . Flats  34  and  38  are parallel horizontal surfaces and are all of substantially equal lengths. Arcuate arches  36  and  40  are also parallel to each other, i.e., they have the same radius of curvature, and are of substantially the same length. 
     In FIGS.  1  and  3 - 5 , the periphery  42  of bottom  12  is supported by being received in linear grooves  44  formed on the interior surface of side walls  14  (FIGS. 3 and 5) and linear groove segments  46  formed on the interior surface of end walls  16  (FIGS.  3  and  4 ), as indicated by the dashed lines. Having periphery  42  of bottom  12  confined in grooves  44  and  46  provides stable support for bottom  12  and any contents received in box  10 . If desired, periphery  42  can be adhesively fixed in grooves  44  and  46  as well. 
     Grooves  46  in end wall  16  appear as two segments separated by arch  40 , as can be more clearly seen in FIG.  4 . As a result, a portion of periphery  42  is exposed beneath arch  40 . Arch  40  and periphery  42  delineate a gap  48  between bottom  12  and end wall  16 . In some uses of box  10 , gap  48  provides a useful function. For instance, certain produce, such as blackberries and strawberries, are placed, when picked, in shallow boxes similar to box  10 . It is desirable to have air circulate through them to maintain their freshness; gaps  48  allow such circulation. Also, it is often desirable to wash fruits or produce after they have been picked. Gaps  48  allow the water to run out the bottom of the box  10 , eliminating the potential problem of the fruit or produce rotting due to sitting in standing water. In other uses, for example as IN- or OUT-boxes, gaps  48  have no immediate function but nonetheless do not detract from the usefulness of box  10 . 
     Referring to FIG. 6, when one box  10 A is stacked on another box  10 B, edge  32 A of end wall  16 A rests on edge  30 B of end wall  16 B, i.e., flats  38 A of box  10 A rest on flats  34 B of box  10 B and arch  40 A of box  10 A mates with arch  36 B of box  10 B. Arches  40 A and  36 B are of sufficient height and radius of curvature to prevent lateral sliding of box  10 A relative to box  10 B. Their curvatures, assisted by gravity, aids in guiding the boxes to fit together compactly in their proper, stable orientation. Flats  34 B coact with flats  38 A to constrain box  10 A from rotating relative to box  10 B, which could happen if arches  40 A and  36 B extended to or beyond corners  20 . Thus, the combination of flats and arches performs three functions, namely, orienting the boxes properly, one directly above the other, preventing relative rotation of the boxes, and effectively resisting lateral, side-to-side movements (indicated by arrows A of FIG. 6) of the boxes relative to each other. 
     In the disclosed embodiment, edge  22 A of side wall  14 A rests on edge  20 B to completely cover and enclose the interior of box  10 B. While in some instances this is desirable, it is not a prerequisite for boxes  10 . By extending end walls  16  higher (not shown) such that vertical edges  28  protrude above the top edges  20  of side walls  14 , a gap can be formed between bottom edge  22 A and top edge  20 B, which may be important, if air circulation is desired or if access to the interior is needed. 
     It will be noted that end walls  16 A and  16 B are coplanar, i.e., they align vertically. Such an alignment would not be possible, except for a shallow, elongated notch  50  at each end of bottom  12 , as most clearly seen in FIGS. 2 and 3. Without notch  50 , the periphery  42  in that area would terminate somewhere within the thickness of end wall  16 , blocking the mating of arches  40 A and  36 B. Each of the notches  50  preferably extends slightly beyond the intersections of arch  40  with periphery  42 , thereby avoiding interference with end walls  16 , terminating short of end walls  16  to form tongues  52  along periphery  42 . Tongues  52  are received in groove segments  46  formed in end walls  16  to support the ends of bottom  12 . (As is apparent from FIGS. 3 and 4, the intersection of arch  40  with the top of groove  46  occurs closer to the center of end wall  16  than does the intersection of arch  40  with the bottom of groove  46 . This structure is manifested in FIG. 3 as flat exposed surfaces  54 .) Notches  50  allow both arches  36 B of box  10 B to bypass the exposed edges of periphery  42 A at each end of box  10 A and loosely grip bottom  12 A therebetween. The overlap of the inside surfaces of end walls  16 B with bottom  12 A prevents longitudinal movement of box  10 A relative to box  10 B in the directions shown by arrows B in FIG.  6 . It can be seen, therefore, that longitudinal and lateral movements between the two boxes is effectively prevented due to the dual arches  36  and  40  of end walls  16 , an aesthetically pleasing design of an extremely simple structure which is economical to manufacture and which produces major beneficial results. 
     FIGS. 7-9 show a few of the permutative possibilities of box  10 . 
     In FIG. 7 box  10  has the same proportions as shown in FIGS. 1-6 but with a divider insert  56  placed inside. Insert  56  as shown comprises a pair of end pieces  58 , longitudinal dividers  60  and transverse dividers  62 , preferably joined together by tongue-and-groove connections, this being a simple, secure joining technique. In the embodiment shown, end pieces  58  fit snugly between side walls  14  and adjacent end walls  16 ; as such, they cover gaps  48 . Longitudinal dividers  60  are fixed to end pieces  58  and run parallel to side walls  14 , dividing box  10  into three, approximately equal compartments  64 ,  66 , and  68 . The middle compartment  66  is further subdivided by transverse dividers  62  into smaller compartments  70 ,  72 , and  74 . This embodiment of box  10  is suitable for use as an organizer tray for small odds-and-ends, such as sewing notions, buttons, pins, spools, etc., where the sealing of gaps  48  is desirable. As shown, box  10  could also be used as a seed box to grow young seedlings. Obviously, the latticework shown in FIG. 6 is but one of many which could be implemented. All variations are considered to be within the purview of the invention. 
     FIG. 8 displays a pencil holder  76  for use with a desk set. Preferably, side walls  14  and end walls  16  have the same lateral dimensions, making bottom  12  square, and all of the walls are made taller than the previous embodiment. While the pencil holder  76  is not intended to be stacked (although it certainly could be), it is an example of how the aesthetic qualities of the smooth, simple lines of basic box  10  can be taken advantage of to design an elegantly styled office accessory. 
     With a few additions, basic box  10  becomes a file box  78  (FIG. 9) for hanging files. Side walls  14  and end walls  16  are again proportioned for the intended use. Hand holds  80  are formed in end walls  16  and a pair of transverse file support bars  82  (only one shown) are affixed to side walls  14  adjacent and parallel to both end walls  16 , respectively. The result is a stackable file box  78 . Of course, hand holds  80  could as easily be formed in side walls  14 , and support bars  82  could be affixed to end walls  16 ; the embodiment shown is merely for illustration. Also, the length of side walls  14  would be selected to accommodate legal- or letter-sized files. 
     It is clear from the above that the objects of the invention have been fulfilled. An open-topped, stackable box has been disclosed which is aesthetically pleasing in appearance, simple in construction, economical to manufacture, and easy to stack and store. 
     Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention as defined in the appended claims. 
     Further, the purpose of the Abstract is to enable the U.S. Patent and Trademark Office, and the public generally, and especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The Abstract is neither intended to define the invention of the application, which is measured solely by the claims, nor is intended to be limiting as to the scope of the invention in any way. 
     It is to be understood, therefore, that the disclosure is by way of illustration only and that the scope of the invention is to be limited solely by the following claims: