Patent Publication Number: US-6702139-B2

Title: Packing tray

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims priority of U.S. Provisional Patent Application Serial No. 60/183,854, filed Feb. 22, 2000, and is a divisional application based on U.S. Patent Application Serial No. 09/790,784, filed Feb. 22, 2001. 
    
    
     BACKGROUND OF INVENTION 
     This invention relates to packing trays and, more particularly, to polystyrene foam trays for packing fruit, and other fragile objects. 
     In the prior art, two basic types of tray packaging have been developed that are commonly used to package fruit, and other fragile objects, such as light bulbs: tray packs and cell packs. (To illustrate the invention, reference herein is made to fruit; other fragile objects can be packed in similar fashion). First, “tray packs” are single stacked trays in which fruit is accommodated. The cells of the tray packs are relatively shallow to maximize the number of cells per unit area formed on a tray. 
     A tray pack that is commonly found in the prior art is embodied in U.S. Pat. No. 3,040,923 to Leitzel, which was issued on Jun. 26, 1962 and is entitled “MOLDED PULP PACKING TRAY”. The Leitzel tray is representative of a typical prior art design and is formed with a plurality of cells, wherein sinuous ridges are formed to separate the cells in a transverse direction, while flat planar portions are used to separate the cells in longitudinal directions. The crests of the sinuous ridges are formed to be higher than the planar portions and to be generally coplanar with the edge of the tray. When stacked, the planar portions of an upper tray bear against fruit packaged in a lower tray. To minimize bruising of the fruit, U.S. Pat. No. 3,040,923 states that contact between packaged fruit and the external surfaces of the cells of an upper tray are not desired. Therefore, it is intended that the planar portions solely bear against the fruit of a lower tray. 
     U.S. Pat. No. 3,962,469 to Leavens et al. which was issued on Jun. 8, 1976 and is entitled “FRUIT TRAY PACKAGE” discloses a fruit tray package arrangement which uses the tray pack disclosed in U.S. Pat. No. 3,040,923. Here, however, it is noted that the Leitzel tray has a shortcoming, wherein a smaller piece of fruit, which is not sufficiently large enough to come into bearing engagement with the associated planar portion of an upper stacked tray, is free to shift about the cell and may be damaged during shipping. To overcome this deficiency, Leavens et al. discloses using a plastic film envelope about each tray which is intended to provide a downward bearing force against each piece of packaged fruit, taking into account variations in size. 
     Second, “cell packs” have been used in the prior art wherein a pair of cooperating trays is disposed in facing relationship to define the cell pack, with fruit being wholly encapsulated between vertically aligned cells of the upper tray and the lower tray. An example of a cell pack is disclosed in U.S. Pat. No. 1,477,921 to Thompson which was issued on Dec. 18, 1923 and is entitled “FRUIT CARRIER”. 
     For transportation and/or storage, packaged cell packs are stacked in cases, or other transportation and/or storage units, often with the cells of all of the cell packs being vertically aligned. Thus, the packaged and stacked cell packs typically do not have any portions in nesting interengagement (i.e., the height of n number of stacked and packaged cell packs is equal to the sum of the individual heights of the packaged cell packs). Alternatively, the Thompson cell pack is made in two variations to allow for nesting, wherein the two variations of cell pack are alternated in a stacked arrangement. 
     Tray packs are packaged and stacked in cases with cells of an upper-stacked tray being nested between the packaged fruit of a lower-stacked tray (i.e., the height of n number of stacked and packaged tray packs is less than the sum of the individual heights of the packaged tray packs). In similar vein to the Thompson cell pack, some tray pack designs are formed in two variations to allow for efficient stacking within the same container. The two designs have different cell arrangements to allow for efficient nesting, yet the tray packs may be stacked within a rectangular cross-sectional container with the edges of the stacked trays being in registration. 
     It is an object of the subject invention to provide a packing tray suitable for use both in a tray pack arrangement and in a cell pack arrangement. 
     It is also an object of the subject invention to provide a packing tray which provides sufficient protection from external hazards, yet is sufficiently versatile to accommodate fragile objects, including fruit, of different sizes, and in different packing orientations. 
     SUMMARY OF THE INVENTION 
     The aforementioned objects of the subject invention are met by a packing tray preferably formed from a sheet of polystyrene foam which is molded into a cellular structure. The cellular structure includes longitudinal rows of cells, wherein alternating rows include odd and even numbers of cells. Preferably, the even number rows include one more cell than the odd number rows. For example, a first row may have six cells, an adjacent row five cells, the following row six cells, and so forth. The cells are arranged so that the centers of even number rows and odd number rows are respectively centered relative to one another. In addition, the centers of the cells of the odd number rows are interposed between the cells of even number rows, and preferably aligned to be centrally disposed between the even number cells. 
     The packing tray is further formed with a peripheral edge which defines a reference plane. Within the packing tray, and bounded by the peripheral edge, is a network of cell dividers which at least partially separate the respective cells. The cell dividers are generally saddle-shaped in cross-section and formed to blend between adjacent cells. Also, posts are located at junctures of cell dividers. It is preferred that the top surfaces of the posts be generally coplanar with the reference plane defined by the peripheral edge, whereas, at least major portions of the cell dividers be recessed below the reference plane. In this manner, the packing tray has a peripheral edge which provides protection for packaged fruit from external forces, yet the tray has relatively low cell dividers which provide versatility in the size of the objects to be packaged, as well as the packaging orientation of the objects, whether being horizontal, vertical, or oblique. 
     With the cellular structure described above, the packing tray of the subject invention can be used in a tray pack application where trays can be reversed end-to-end and stacked upon one another. In contrast to the manner of packing the prior art Leitzel tray, fruit, or other objects, packed with the tray of the subject invention will preferably simultaneously bear against the exterior surfaces of at least two cells of an upper-stacked tray. The simultaneous engagement against the upper cells limits the relative movement of the fruit, or object, and prevents bruising thereof. Due to the forgiveness of the constituent foam material of the packing tray, and the smooth outer surfaces of the cells, it has been found that the bearing engagement of the cells against the fruit is acceptable and does not result in excessive bruising, or other damage. The Leitzel tray is formed from molded pulp which does not define smooth outer surfaces, and the inherent forgiveness of the material is much more limited than that of polystyrene foam. 
     Additionally, the packing tray of the subject invention can be used in a cell pack arrangement, wherein two of the packing trays can be placed in facing relationship to encapsulate fruit or other objects. The cell dividers and the posts provide for separation between adjacent packed objects. In addition, the increased heights of the peripheral edges of the two packing trays from the respective cell divider networks cause the peripheral edges to depend over substantial portions of the peripheries of the cell pack to provide a buffer against external forces while in a cell pack arrangement—it should be noted that it is preferred that the peripheral edges do not contact. If the depths of the cells were to be increased so as to enable abutting contact between the peripheral edges of the two trays in a cell pack arrangement (as in the prior art), the number of cells the packing trays could accommodate would be limited. To achieve the highest economy of a tray, the greatest number of cells per unit area is to be provided. The subject invention achieves this objective by having the peripheral edges be spaced apart in a cell pack arrangement (in contrast to the prior art), without sacrificing the amount of protection afforded packaged objects. 
     These and other features of the invention will be better understood through a study of the following detailed description and accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a top plan view of a packing tray formed in accordance with the subject invention; 
     FIG. 2 is a partial cross-sectional view taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a partial bottom plan view of the packing tray; 
     FIG. 4 is a schematic showing the packing tray of the subject invention being used in a cell pack arrangement; and 
     FIG. 5 is a schematic showing the packing tray of the subject invention being used in a tray pack arrangement. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the Figures, a packing tray is shown and generally designated with the reference numeral  10 . The packing tray  10  is preferably formed from a single sheet of polystyrene foam using techniques known by those skilled in the art and is preferably formed with matching upper and lower surfaces so that the packing tray  10  can be stacked in nesting engagement with similarly-shaped packing trays  10 . The packing tray  10  is particularly well-suited to pack fruit and other comestibles, but can be used as well to pack other fragile objects, such as light bulbs. By way of non-limiting example, reference is made herein to packaging fruit to describe the invention. 
     The packing tray  10  has a cellular construction with a plurality of cup-shaped cells  12  formed to accommodate the fruit to be packed therein. The cells  12  are arranged in longitudinal rows, where is it is preferred that alternating rows include odd and even numbers of cells. More preferably, the even number rows include one more cell than the odd number rows. For example, rows  14 A include six of the cells  12 , while rows  14 B include five of the cells  12 . It is preferred that the centers of the cells of alternating rows  14 A,  14 B be aligned laterally. To illustrate this point, reference is made to cell centers  16 A- 16 F, wherein lateral axes  18 A- 18 C are respectively defined between pairs of cells centers  16 A- 16 B,  16 C- 16 D,  16 E- 16 F, respectively. It is preferred that the lateral axes  18 A- 18 C be generally parallel. It is also preferred that the cell centers  16 C,  16 D of the odd number rows  14 B be centered relative to the cell centers  16 A,  16 B,  16 E,  16 F of the even number rows  14 A. With this arrangement, the lateral axis  18 B is generally equidistant from both of the lateral axes  18 A and  18 C, being spaced a distance S from each. It is also preferred that an even number of total rows  14 A,  14 B be provided to allow for reversed end-to-end stacking as described below. As shown in FIG. 1, four total rows  14 A,  14 B are defined in the tray  10 . 
     The packing tray  10  is generally rectangular shaped, with a longitudinal dimension X and a lateral dimension Y. The dimensions X, Y can be varied to accommodate various numbers of the cells  12 . To maximize the economy of the packing tray  10 , it is preferred that the greatest numbers of the cells  12  be provided within the area X•Y that is feasible. 
     A peripheral edge  20  extends about the perimeter of the packing tray  10  with an upper surface  19  having co-planar portions that define a reference plane R, as shown in FIG.  2 . The peripheral edge  20  may also be interrupted by reliefs  21 , which provide rigidity to the packing tray  10 . The peripheral edge  20  is formed as a flange of the packing tray  10  and has varying widths. For example, the peripheral edge  20  defines a greater width between the perimeter of the packing tray  10  and the cell  12  designated with the cell center  16 C than the width defined between the perimeter of the packing tray  10  and the cell  12  designated with the cell center  16 E. 
     Bounded by the peripheral edge  20  is a network of cell dividers  22  which are generally saddle-shaped in cross-section and formed to separate, and blend with, adjacent cells  12 . Further, posts  26  are located at junctures of the cell dividers  22 . As shown in the FIGS., the posts  26  may be located at junctures of three of the cell dividers  22 , but other arrangements are possible. It is preferred that top surfaces  28  of the posts  26  be generally coplanar with the reference plane R, while at least major portions of the cell dividers  22  be recessed below the reference plane R. (As used herein, a “major portion” of a cell divider is at least half the length of the cell divider.) With reference to FIG. 2, major portions of the crests  30  of the cell dividers  22  are recessed below the reference plane R. The crests  30  preferably blend with the top surfaces  28  of the posts  26  and with the upper surface  19  of the peripheral edge  20 , and, thus, the blended portions of the crests  30  are not recessed below the reference plane R. If the crests  30  were to blend with the posts  26  below the top surfaces  28  and with side walls (defined below) of the cells  12 , the cell dividers  22  would be wholly recessed below the reference plane R. 
     The cells  12  are generally cup-shaped and each is defined, to varying extents, by a combination of the cell dividers  22 , the posts  26  and side walls  24 . For illustrative purposes, with reference to FIG. 1, the cell  12  located at the corner of the packing tray  10  and designated with the cell center  16 E is defined by two of the cell dividers  22 , one of the posts  26  and one of the side walls  24  (see FIG.  2 ); the cell  12  located at the periphery of the packing tray  10 , but not at any of the corners, and designated with the cell center  16 C, is defined by five of the cell dividers  22 , four of the posts  26 , and one of the side walls  24 ; and, the cell  12  located on the interior of the packing tray  10  and designated with the cell center  16 B is defined by six of the cell dividers  22  and six of the posts  26 . The specific construction of the cells  12  depends on the location of the cell  12  relative to other of the cells  12  and relative placement on the packing tray  10 . 
     Also, the cells  12  are each formed with a bottom  23 . Depending on the particular cell  12 , the cell dividers  22 , the posts  26  and the side walls  24  extend continuously upwardly from the cell bottom  23  so as to bound the cell bottom  23 . The shape of the cell bottoms  23 , as well as the cell dividers  22 , the posts  26  and the side walls  24  is dictated by the fragile objects that are to be packed in the packing tray  10 . For example, fruit is generally spherical (or at least has spherical portions) and thus the cells  12  are shaped accordingly—the cells bottoms  23  are dished, and the cell dividers  22 , the posts  26  and the side walls  24  are arcuately shaped in two coordinate directions. The cells  12  need not be formed about a single radius and varying curvatures are possible. In addition, the lengths of the cell dividers  22 , the posts  26  and the side walls  24  may be varied. 
     With reference to FIG. 3, the posts  26  are each generally formed with a tapered six-sided shape that terminates with the top surface  28  being generally hexagonal. For each of the posts  26 , three of the cell dividers  22  define three of the sides. In between the cell dividers  22 , the posts  26  have post walls  25  that extend continuously between adjoining cell dividers  22  so as define uninterrupted surfaces in the cells  12 . At the periphery of the packing tray  10 , the cell dividers  22  extend between one of the posts  26  and the peripheral edge  20 . The side walls  24  sweep about the respective cell  12  and connect the cell dividers  22  where there is no post  26 . 
     It should be noted that in forming the packing tray  10 , the cells  12 , and features thereof, are sculpted into the constituent foam material. Although there are transitional surfaces and directional changes in the surfaces, the various transition surfaces and changes in direction are blended together in an aesthetically-pleasing manner so that the changes are relatively imperceptible. Sharp corners are generally avoided. FIG. 3 is a partial bottom plan view of the packing tray  10  showing the corner of the packing tray  10  which is in proximity to cell  12  designated with the cell center  16 D in FIG.  1 . In FIG. 3, dashed lines partially bound an area of the packing tray  10  in which solid lines demarcate for illustrative purposes the transition surfaces and changes of direction. The remainder of the packing tray  10  is formed in similar fashion. 
     Referring again to FIG. 2, the cell dividers  22  are preferably convexly shaped in profile so as to each define a low point  27 . Preferably, the low point  27  is located at a mid-point between adjoining posts  26 , or at a mid-point between the peripheral edge  20  and adjoining post  26  where the cell divider  22  extends from the peripheral edge  20 , and, more preferably, at the respective central mid-point. As a result of this structural arrangement, the side walls  24  extend coextensively with the posts  26  and beyond at least major portions of the cell dividers  22 . 
     The packing tray  10  of the subject invention can advantageously be used in both cell pack and tray pack applications. With reference to FIG. 4, two of the packing trays  10 A,  10 B can be placed in facing relation, such that fruit F can be packaged therebetween. The odd/even numbering of the cells  12  described above, allows for the packing trays  10 A,  10 B to be of identical construction, but in inverted relation with the rows  14 A and the rows  14 B of the two trays  10 A and  10 B being vertically aligned. 
     In contrast to the prior art, the packing trays  10 A,  10 B do not fully encapsulate the fruit F. Rather, a gap  32  is defined therebetween having a width W. By having the gap  32 , depth D of the cells  12  (as measured from the peripheral edge  20 ) is limited. It is preferred that the depth D be less than one-half the nominal height of the fruit F. To decrease the width W, the depth D is increased. Additionally, cell density in a packing tray (i.e., number of cells per unit area) is inversely proportional to the depth of the cells. In other words, a greater number of shallower cells can be formed in a tray of given area than a number of deeper cells, in the same area. It is preferred with the packing trays  10 A,  10 B that the maximum full diameter T 1  of the cells  12  be less than the nominal maximum diameter T 2  of the fruit F, thereby providing for relatively shallow cells which can be densely formed. (As used herein the “maximum full diameter” is measured where the cell  12  defines a full enclosed perimeter in a horizontal plane; here, the maximum full diameter coincides with the low point  27 . Above the low point  27 , the cell  12  does not define a full enclosed perimeter.) Accordingly, the subject invention facilities maximum economy of cell density. 
     The following ranges of dimensions can be used with the subject invention: the width W having a range of 0.5″-1.0″, inclusive; the depth D having a range of 1″-1.625″, inclusive; and the maximum full diameter T 1  having a range of 2.375″-3.25″ inclusive. The actual dimensions will be dependent upon the dimensions of the fruit F, including the nominal diameter T 2 . It is preferred that the depth D be equal to or greater than the width W. It is also preferred that the low points  27  of the cell dividers  22  be located a distance Z from the peripheral edge  20  which is equal to one-half the depth D. 
     Another benefit of the subject invention lies in the recessing of the cell dividers  22  below the peripheral edge  20 . In this manner, the side walls  24  extend beyond at least major portions of the cell dividers  22  and form peripheral buffers about the respective packing trays  10 A,  10 B. Yet, the cell dividers  22  allow for accommodation of different sized fruit F, due to their limited height, and enable versatility in packing orientation (e.g., fruit can be packed on its side, rather than upright). Furthermore, the constituent foam material of the packing tray  10  imparts the cell dividers  22 , the posts  26  and the side walls  24  with forgiveness which allows for limited expansion of the cells  12  in accommodating larger fruit than for which the cells  12  are designed, thereby providing for variations in size in the fruit. 
     When packed, the cell packs are stacked with the cells  12  being in vertical alignment. As such, the cell centers, such as cell centers  16 E of the packing trays  10 A,  10 B generally lie along a common vertical axis  34  and the peripheral edges  20  are in registration. The cell packs can then be packed in a case, or other transportation/storage container, having an internal area of slightly greater than X•Y to accommodate the packing trays  10 A,  10 B. 
     With reference to FIG. 5, the packing tray can be also used in a tray pack arrangement. Here, packing trays  10 C,  10 D are arranged such that the fruit F of the lower stacked packing tray  10 D is nested between, and in abutting contact with, the exterior surfaces of at least two of the cells  12  of the upper stacked packing tray  10 C. The bearing engagement of the cells  12  against the fruit F provides a holding force therefor. The cells  12  are preferably formed with smooth outer surfaces to limit damage to the fruit F. Also, the forgiveness of the constituent foam material of the packing trays provides compressibility which deflects under weight of the fruit F and also acts to limit damage to the fruit F. 
     The configuration of the cells  12  of the packing tray  10  described above allows for the packing trays  10 C,  10 D to be identically formed. To obtain the stacked relationship shown in FIG. 5, the packing trays  10 C,  10 D are placed in reversed end-to-end relationship. To illustrate this point, reference is made to FIG.  1  and it is indicated that solid lines depict the lower stacked packing tray  10 D, while the cells  12 ′, shown in dashed lines, represent a portion of the upper stacked packing tray  10 C in a stacked tray pack arrangement. In this arrangement, the cells  12 ′ are not vertically aligned with the cells  12 . This result is achieved by rotating the packing trays so that the cell center  16 E of the lower stacked packing tray  10 D is directed towards the upper right corner of FIG. 1, and the corresponding cell center  16 E′ of the upper stacked packing tray  10 C is directed towards the lower left corner of FIG.  1 . 
     The same advantages of the low cell dividers  22  described above are equally applicable in this application. Also, the relative dimensioning of the depth D of the cells  12  described above provides the packing tray  10  with deeper cells than a prior art tray pack design, and as such, more protection in packing. In sum, it is preferred that the cells  12  be formed with a depth that is greater than found in prior art tray packs, but less than that found in prior art cell packs. 
     As is readily apparent, numerous modifications and changes may readily occur to those skilled in the art. Hence, it is not desired to limit the invention to the exact construction and operation shown and described and, accordingly, all suitable modification equivalents may be resorted to falling within the scope of the invention as claimed.