Nestable case
BACKGROUND OF THE INVENTION 
     This invention relates to cases for holding a plurality of containers, and more particularly to a case that can be stacked onto a second case of similar construction when both cases are filled to capacity, and nested inside the second case when both cases are empty. 
     Beverages, such as milk and soda, are generally sold at the retail level in individual containers of well-known size and shape. The beverage containers, which are often made of glass, plastic or paper constituents, are usually packed in predetermined quantities in cases for delivery from a bottler or container filling location to a distributor or retail outlet. 
     Since enormous quantities of such containers are transported from the filling location or distributor to the retailer, on a daily or weekly basis, it has long been a practice in the industry to provide reusable delivery cases. The reusable delivery cases are normally made of wood or plastic formed into a rigid, durable box-type structure. 
     One popular type of reusable delivery case made of plastic and known as a full-depth case, accommodates the entire height of containers packed therein and can be stacked onto other fully packed delivery cases. Generally the fully packed delivery cases are stacked on pallets in a predetermined fashion to facilitate loading and unloading of a transport vehicle. After the delivery cases are unloaded and unpacked they must be returned to the container filling location for reuse in packing newly filled containers. 
     Although empty delivery cases weigh substantially less than full cases, they occupy the same storage volume as a fully loaded delivery case. Consequently, the fuel costs for returning a cargo of empty delivery cases from a retailer back to a container filling location is essentially the same as the fuel costs for transporting the fully loaded cases from the container filling location to the retailer. 
     As fuel costs continue to increase, the burden of transporting empty cases at a cost that compares to that of delivering fully loaded cases becomes more and more objectionable. For a long time however, this problem has defied solution. 
     Oftentimes a cargo of loaded cases delivered to a retailer is not immediately unpacked. After the delivery cases are eventually unpacked they are temporarily stored at the retail facility for later pickup and return to the container filling location. Storage of empty delivery cases at a retail facility is a considerable problem since space is held at a premium. Consequently the empty delivery cases are often stored in an outside area so that the interior storage space can be used for incoming goods. 
     However, outdoor storage of empty delivery cases also presents further problems. Delivery cases left outdoors are often purloined to an extent that has aroused the concern of retailers and packers, who now expend additional money in theft prevention techniques and in financing organizations that attempt to recover stolen delivery cases. 
     It is thus desirable to provide a delivery case for containers which, when fully packed, can be stacked on other fully packed delivery cases but which takes up substantially less storage space when empty by being nestable in other similar empty delivery cases. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Among the several objects of the present invention may be noted the provision of a novel case for holding a plurality of containers, a novel case that can be stacked on a second case when both cases are fully loaded and can be nested inside the second case when both cases are empty, a novel case that has an expanded limit condition to accommodate a full load and a contracted condition which permits nesting of empty cases, a novel case with deflectable side walls and a contractable base, and a novel case with novel interlocking projections that permit stacking of cases in a pinwheel configuration. 
     Other objects and features will be in part apparent and in part pointed out hereinafter. 
     The present invention relates to a novel case that has an expanded limit position for holding a full load of containers and a contracted condition, when empty, that permits nesting of empty cases. 
     In one embodiment of the invention the nestable case has an expanded limit position wherein the case is in the general shape of a box with four side walls and a base portion. Each of the wall members has a moveable wall portion joined to the base by a hinging arrangement. 
     The base includes a median section and foldable sections that extend from the median section to the respective moveable wall portions, and are joined to the moveable wall portions by the hinging arrangement. A clearance space provided between neighboring wall portions that continues into the base permits pivotal movement of the moveable wall portions from an expanded limit position to a contracted position. The case will accommodate a full load of containers when it is in its expanded limit position. 
     The wall portions of the case, collectively at their free ends, define a mouth of fixed size for the case. The base, however, has an expanded size which bridges the mouth of another similar case when the moveable wall portions are in their expanded limit position. Conversely, when the moveable wall portions are in their contracted position the base contracts to a contracted base size that is less than the fixed size of the mouth of another similar case to permit the base of one case to fit in the mouth of another case. 
     When the case is empty and in its contracted position, the moveable walls are inclined to the base and the base is likewise contracted. Consequently each empty case can be nested to form a stack of empty cases. In a stack of nested empty cases, the spacing between consecutive base portions is substantially less than the overall wall height from the base to the mouth of the case. 
     To facilitate stacking of fully loaded cases, protrusions are provided on an outside surface of the base in predetermined positions. The stacking position of one fully loaded case on another fully loaded case is thus predetermined by engagement of the protrusions of one case in the mouth of the next lower case in a stack. The protrusions can be provided at respective predetermined spacings on the outside surface of the base to permit stacking of fully loaded cases in a predetermined pinwheel configuration. 
     Recesses or openings can also be provided in the base, to accommodate the protrusions, when the case is in its contracted position. The openings thus provide clearance for the protrusions to permit maximum contracting of the case. 
     If desired, the openings can be sized to provide a detent engagement with the protrusions to maintain the empty case in its contracted position until the moveable walls are urged by a full load of containers into the expanded limit position. 
     In a further embodiment of the invention, a moveable corner flap section is provided next to neighboring pairs of moveable wall portions. The flap section thus provides corner protection in the clearance spaces between the neighboring wall portions. 
     The invention accordingly comprises the constructions hereinafter described, the scope of the invention being indicated in the following claims. 
    
    
     DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings, in which various possible embodiments of the invention are illustrated, 
     FIG. 1 is a perspective view of a case incorporating one embodiment of the invention; 
     FIG. 2 is a sectional view, taken on the line 2--2 of FIG. 1, showing the expanded limit position of the case, when fully loaded; 
     FIG. 3 is a sectional view similar to FIG. 2, but showing the contracted condition of the case when empty; 
     FIG. 4 is a sectional view of a stack of nested empty cases; 
     FIG. 5 is a bottom view of the case in its expanded limit position; 
     FIG. 6 is a top view of a plurality of cases stacked in a pinwheel configuration; 
     FIG. 7 is an enlarged fragmentary sectional view of the expanded limit position of the case; 
     FIG. 8 is an enlarged fragmentary sectional view of the contracted condition of the case; 
     FIG. 9 is a view similar to FIG. 7 showing another embodiment of the invention; 
     FlG. 10 is a partially exploded fragmentary perspective view of another embodiment of the invention; and, 
     FIG. 11 is the embodiment of FIG. 10 in assembled condition. 
     Corresponding reference characters indicate corresponding parts throughout the several views of the drawings. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, a case incorporating the present invention is generally indicated by the reference number 10 in FIG. 1. 
     The case 10, which is preferably formed of polyethylene, is generally box-shaped and includes four side walls 12, 14, 16 and 18 joined by a base 20. A mouth 22 of the case 10 is defined by the collective free ends of the walls 12, 14, 16 and 18. 
     A wall clearance opening 24 is provided at the corner junction of the neighboring walls 12 and 18 of the case 10. The wall clearance opening 24 starts at a predetermined distance from the mouth 22 of the case and diverges as it extends toward the base 20. A base clearance opening 26 is provided at a corner of the base 20 corresponding to the corner junction of the neighboring walls 12 and 18. The wall clearance opening 24 thus continues into the base clearance opening 26. 
     Additional wall clearance openings 28, 30 and 32 (FIG. 5) corresponding to the wall clearance opening 24 are respectively provided at the corner junctions of the neighboring walls 12, 14; 14, 16; and 16, 18. Also, additional base clearance openings 34, 36 and 38 (FIG. 5) corresponding to the base clearance opening 26 are respectively continuous with the wall clearance openings 28, 30 and 32. 
     Referring to FIG. 5, the base 20 includes a median section 40 and foldable sections 42, 44, 46 and 48 that respectively extend from the median section 40 to the side walls 12, 14, 16 and 18. The foldable section 42 is hinged to the median section 40 at hinge 50. Similarly the foldable sections 44, 46 and 48 are hinged to the median section 40 by the respective hinges 52, 54 and 56. 
     Unless otherwise stated, the term hinge refers to a molded hinge structure of the type known as a living hinge. The foldable section 42 is likewise hinged to the wall portion 12 at a hinge 58. Similarly the foldable sections 44, 46 and 48 are hinged to the respective side walls 14, 16 and 18 by the hinges 60, 62 and 64. 
     Each foldable section 42, 44, 46 and 48 includes two foldable segments hinged to each other. Thus the foldable section 42 includes foldable segments 66 and 68 hinged at 70. The foldable section 44 includes foldable segments 72 and 74 hinged at 76. Also the foldable section 46 includes foldable segments 78 and 80 hinged at 82. And the foldable section 48 includes foldable segments 84 and 86 hinged at 88. 
     A plurality of protrusions 90 having a predetermined spacing are formed on the foldable segments 66, 72, 78 and 84, whereas a corresponding plurality of openings 92 are formed in the foldable segments 68, 74, 80 and 86 to accommodate the protrusions 90. The openings 92 can be sized to provide full clearance for the protrusions 90 or can be sized to provide a slight detent engagement with the protrusions 90. 
     Referring to FIG. 1 the side wall 12 includes a fixed wall portion 94 and a moveable wall portion 96 moveable about a fold axis 98 and hinged to the base at the hinge 58 (FIG. 5). A handle opening 100 is provided in the fixed wall portion 94. Similarly the side wall 14 includes a fixed wall portion 102 and a moveable wall portion 104 (FIG. 4) moveable about a fold axis 106 and hinged to the base 40 at the hinge 60 (FIG. 5). 
     Referring to FIGS. 1, 2 and 5 the side wall 16 likewise includes a fixed wall portion 108 and a moveable wall portion 110 moveable about a fold axis 112 and hinged to the base 40 at the hinge 62. A handle opening 114 is provided in th fixed wall portion 108. Also the side wall 18 includes a fixed wall portion 116 and a moveable wall portion 118 moveable about a fold axis 120 and hinged to the base 40 at the hinge 64. 
     In using the case 10, a plurality of containers such as two-liter soda bottles 122 and 124 are arranged side by side in the case 10 as shown in FIG. 1. Since the case 10 is sized to accommodate the full height of the soda bottles 122, 124 it is known as a full depth case. 
     The case 10 is of a predetermined size such that it becomes fully loaded when a predetermined number of containers are disposed therein. For example, the case 10 is fully loaded when six two-liter soda bottles are disposed therein. When the case is fully loaded it is in its expanded limit position, which is characterized by the foldable sections 42, 44, 46 and 48 of the base 20 being substantially coplanar with the median section 40 as shown in FIGS. 2 and 5. The expanded limit position of the case 10 is further characterized by the moveable wall portions 96, 104, 110 and 118 being at a first predetermined angle with respect to the base 20, which angle is approximately 90 degrees such as shown in FIG. 2. 
     It will be most apparent from FIG. 2 that the case 10 is sized such that the side-by-side arrangement of the containers 122 and 124 urges the moveable wall portions 104 and 118 into their expanded limit position. Similarly, when three of the bottles are in side-by-side arrangement as shown in FIG. 1, they urge the moveable wall portions 96 and 110 into their expanded limit position, and simultaneously the foldable sections 42, 44, 46 and 48 of the base 20 are disposed in their expanded limit positions. 
     As shown in FIG. 5 the protrusions 90 are located on the foldable sections 42, 44, 46 and 48 such that they are received inside the mouth 22 of a lower case similar to case 10 in a stack of fully loaded cases. The protrusions 90 by depending into the mouth 22 of a lower case in a stack, help to locate the stacking positions of fully loaded cases and also prevent dislodging of the cases once they are stacked. 
     With the case 10 in its fully loaded condition the moveable wall portions 96, 104, 110 and 118 are substantially coplanar with the fixed wall portions 94, 102, 108 and 116 such that all wall portions are substantially perpendicular to the base 20. Consequently, when one fully loaded case is stacked on another fully loaded case, with both cases being in similar orientation, the weight of the upper fully loaded case is borne by the walls of the lower fully loaded case. 
     If desired, fully loaded cases can be stacked on a pallet to facilitate loading and unloading of a cargo of cases. It has been found that certain stacking arrangements of cases are more stable than others, especially a stacking arrangement known as the pinwheel configuration as illustrated in FIG. 6. The pinwheel configuration is especially suited for loading cases that have two relatively short sides and two relatively long sides. Accordingly, a pair of similarly oriented cases is placed adjacent a pair of cases that is oriented 90 degrees relative to the orientation of the first pair of cases and so on to form a closed pinwheel pattern. 
     The next layer of cases is loaded in similar fashion except that the pinwheel pattern is rotated approximately 90 degrees relative to the first pinwheel pattern such as shown in dotted outline in FIG. 6. The protrusions 90 are arranged on the respective bases 20 of all cases in a manner that insures engagement of the free ends of the wall portions of a lower case intermediate preselected protrusions in the base of an upper case. 
     For example, referring again to FIG. 6, the top cases in the pinwheel stacking arrangement are shown in solid line and the lower cases in said stack are shown in dotted outline. An upper case 10a has protrusions 90j and sits upon two lower cases 10q and 10p. Wall portions of the lower case 10q and the lower case 10p are disposed between the protrusions 90j of the base of the upper case 10a. Another upper case 10b sits upon the lower case 10q, the lower case 10p and a lower case 10r. Wall portions of the lower case 10q and 10p are disposed between projections 90j of the upper case 10b. In addition, wall portions of the lower case 10q, the lower case 10p and the lower case 10r are disposed between the projections 90k on the base of the upper case 10b. An upper case 10c is stacked upon portions of the lower case 10r and 10s. Wall portions of the lower case 10r and the lower case 10s are disposed between the projections 90j formed at the base of the upper case 10c in the same fashion as the upper case 10a was stacked on the lower cases 10p and 10q. 
     In addition, an upper case 10d is supported on portions of the lower case 10r, the lower case 10s and a lower case 10t. Thus, wall portions of the case 10r and the case 10s are disposed between projections 90j of the upper case 10d. In addition, wall portions of the lower case 10r, 10s and 10t are disposed between the projections 90k on the base of the upper case 10d in the same fashion as the upper case 10b is supported on portions of the lower cases 10p, 10q and 10r. 
     The support arrangement for the upper cases 10e, 10f, 10g and 10h is similar to that described for the cases 10a, 10b, 10c and 10d. Thus, the predetermined arrangement and spacing of the projections 90 on the cases 10 insure a stable and secure stacking arrangement of such cases in a pinwheel configuration. 
     Once a case 10 is emptied by removing the containers, the moveable wall portions such as 104 and 118 of FIG. 3 will normally move to a contracted position about the fold axes 106 and 120 (FIG. 4) especially if the cases are originally molded in a contracted position. A similar contracting movement of the moveable walls 96 and 110 will also occur with respect to the fold axes 98 and 112 (FIGS. 1 and 4). 
     A typical contraction of the base 20 is shown in FIGS. 7 and 8. Thus when a moveable wall portion 104 as shown in FIG. 7 is moved to its contracted limit position the foldable segments 72 and 74 converge toward each other about the hinge 76. Moreover, the moveable wall portion 104 converges toward the foldable segment 72 about the hinge 60. Consequently, when the case is in its contracted limit position the protrusion 90 is accommodated in the opening 92 to assure maximum contraction. If desired, the opening 92 can be sized to provide a slight detenting engagement with the protrusion 90 to maintain the case 10 in its contracted limit position when empty. 
     As most clearly shown in FIG. 4 the case 10 when empty is receivable in the mouth 122 of another similarly empty case to provide a nestable stacking arrangement. It will be noted that the fixed wall portions 94, 102, 108 and 116 are rigidly joined to each other and do not pivot or deflect when the associated moveable wall portions move from their expanded limit position to their contracted positions. Thus the nesting depth of one case with respect to another case is determined by the engagement of the fixed wall portions of an upper case with the mouth 122 of a lower case in the nested stacking arrangement as shown in FIG. 4. 
     In another embodiment of the invention as shown in FIG. 9, the previously described living hinges are replaced by separate hinges such as shown at 130, 132 and 134. 
     In a still further embodiment of the invention as shown in FIGS. 10 and 11, a case 140 identical to the case 10 is fully loaded with milk containers such as 142 and 144 of a well known conventional structure. The milk container 142 includes a corner portion 146 projecting from the wall clearance opening 24 and the base clearance opening 26. Other milk containers in the remaining three corner locations of the cas 140 include similarly projecting corner portions. 
     Since the milk container is made of a paperboard construction it might be subject to damage at the area where the corner portion 146 projects from the clearance openings 24 and 26. Thus a flap portion 148 formed of a suitable gauge plastic includes two sections 150 and 152 at right angles to each other with an end fold 154. The flap portion 148 is secured to the interior surface of the walls 12 and 16 for example, by engagement of the end fold 154 with the corner junction, as shown in FIG. 11. 
     Securement of the flap portion 148 to the walls 12 and 16 can also be accomplished by engagement of projections 156 on the flap portion 148 with corresponding holes 158 provided in the walls of the case 10 as shown in FIGS. 10 and 11. The flap portion 148 can thus move with the corresponding moveable wall portions 96 and 118 when such moveable wall portions undergo movement from their expanded limit position to the contracted limit position. If desired, a clearance notch (not shown) can be provided in the sections 150 and 152 to avoid interference with the foldable sections 42, 44, 46 and 48 of the base 20. 
     Under this arrangement the flap portion 148 protects the projecting corner portion 146 of the milk container from any bruising that might occur when one fully loaded case 140 is bumped against another similarly fully loaded case. 
     As will be apparent to those skilled in the art the case 10 can be made in any selected size depending upon the type of container and quantity of containers being packed. The arrangement and spacing of the protrusions 90 can be developed to permit known stacking arrangements other than the pin-wheel configuration. Such arrangement and spacing of the protrusions 90 would depend upon the size of the pallet and the size of the cases being used. 
     In view of the above it will be seen that the several objects of the invention have been acheived and other advantageous results attained. 
     As various changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.