BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates generally to storage systems and containers. 
         [0002]    Some automated storage and retrieval systems include racks having rows and columns of shelves provided by pairs of spaced-apart supports or rails. Trays are supported on the rails. Objects are stored on the trays and the trays and objects are stored in the racks. The automated retrieval equipment lifts and retrieves selected trays from the rails when necessary. 
       SUMMARY OF THE INVENTION 
       [0003]    The present invention provides a tray and tub assembly, particularly useful in a storage system. The tray can be used on the known storage and retrieval racks. The tub is removably securable to the tray. The tub includes a bottom wall, a pair of opposed side walls and a pair of opposed end walls. The bottom wall of the tub is removably secured to the tray. Thus, some of the trays in the storage system can be provided with tubs for the storage of loose items. 
         [0004]    Because the tub will be connected to and supported by the tray, the tub does not have to be rigid enough to support itself and its load on the spaced-apart rails of the rack. Also, connecting the tubs to the trays provides uniformity in the handling and storage of the trays, i.e. trays with and without tubs can be handled similarly. Because the tub does not need to provide rigid support, the tub need not be reinforced with ribs and can even be thermoformed. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    Other advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein: 
           [0006]      FIG. 1  is a perspective view of a tub and tray storage system according to the present invention. 
           [0007]      FIG. 2  is a top view of the tub and tray of  FIG. 1 . 
           [0008]      FIG. 3  is a side view of the tub and tray. 
           [0009]      FIG. 4  is a front view of the tub and tray. 
           [0010]      FIG. 5  is a perspective view of the tray of  FIG. 1 . 
           [0011]      FIG. 6  is an enlarged view of a portion of the upper surface of the tray of  FIG. 5 . 
           [0012]      FIG. 7  is a side view of the tray. 
           [0013]      FIG. 8  is a front view of the tray. 
           [0014]      FIG. 9  is an enlarged perspective view of a portion of the tub of  FIG. 1 . 
           [0015]      FIG. 10  is a front view of the tub. 
           [0016]      FIG. 11  is a side view of the tub. 
           [0017]      FIG. 12  is a perspective view of the tub of  FIG. 1  having a similar tub nested therein. 
           [0018]      FIG. 13  is a section view of the tubs of  FIG. 12 . 
           [0019]      FIG. 14  is a section view through the tub and tray of  FIG. 1 . 
           [0020]      FIG. 14A  is an enlarged view of Area A of  FIG. 14 . 
           [0021]      FIG. 14B  is an enlarged view of Area B of  FIG. 14 . 
           [0022]      FIG. 15  is a front view of a storage system including a plurality of the tubs and trays of  FIG. 1 . 
           [0023]      FIG. 16  is a bottom perspective view of an alternate tray. 
           [0024]      FIG. 17  is a front view, partially broken away, of the tray of  FIG. 16  on supports similar to the supports of  FIG. 15 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0025]    Referring to  FIG. 1 , a storage assembly  10  according to one embodiment of the present invention includes a tub  12  supported by and removably secured to a tray  14 . The tub  12  includes a bottom wall  16  up from which extend side walls  18  and end walls  20 . A lip  24  protrudes outward from the upper edge of the side walls  18  and end walls  20 . As shown, the height of the end walls  20  may be significantly less than that of the side walls  18  to define access openings  22 . Alternatively, the end walls  20  could be the same height as the side walls  18 . The bottom wall includes a plurality of connector openings  30  and alignment openings  32 . 
         [0026]    The tray  14  includes a bottom wall  26  having a plurality of ribs  28  including a peripheral rib  29  extending upward therefrom. The tray  14  further includes a plurality of connectors  34  and alignment features  36  protruding upward. The connectors  34  extend through the connector openings  30  of the tub  12  to connect the tray  14  to the tub  12 . The alignment features  36  extend through the alignment openings  32  to align the tub  12  to the tray  14 . 
         [0027]      FIG. 2  is a top view of the storage assembly  10  of  FIG. 1 . The connector openings  30  include a large portion  38  contiguous with a small portion  40 . The large portion  38  and the small portion  40  are both defined by a flange  44 , which is generally a portion of the bottom wall  16  having reduced thickness. The alignment openings  32  also are defined by a flange  48 , which is generally a portion of the bottom wall  16  having reduced thickness. 
         [0028]      FIG. 3  is a side view of the tub  12  and tray  14 .  FIG. 4  is a front view of the tub  12  and tray  14 . Preferably, if the tub  12  and tray  14  are to be used in a storage system, the tub  12  does not extend past the edges of the tray  14 . 
         [0029]      FIG. 5  is a perspective view of the tray  14 , which can be used independently of the tub  12  ( FIG. 1 ). The plurality of ribs  28  may be formed in a grid as shown or in other arrangements. The plurality of connectors  34  and alignment features  36  protruding upward from raised portions of the bottom wall  16 , as shown more clearly in  FIG. 6 . The connectors  34  and alignment features  36  are equal in height to the ribs  28  to provide a generally planar upper surface. Alternatively, they may be recessed relative to the plurality of ribs  28  as shown, or could have greater height than the ribs  28 . The ribs  28  preferably extend upward from the bottom wall  16  as shown, so that a smooth bottom surface is provided which is better suited for sliding along surfaces in the storage and retrieval system. Alternatively, however, the ribs  28  could extend downward from the wall to provide a smooth upper surface. As another alternative, a wall could be welded to outer ends of the ribs  28 , whether extending upwardly or downwardly, in order to provide smooth upper and lower surfaces and added strength. 
         [0030]      FIG. 7  is a side view of the tray  14 .  FIG. 8  is a front view of the tray  14 . 
         [0031]      FIG. 9  is an enlarged perspective view of a portion of the tub  12  of  FIG. 1 , illustrating one of the connector openings  30  and two of the alignment openings  32 . The flange  44  of the connector opening  30  includes a neck  46  between the large portion  38  and the small portion  40 , reducing the dimension of the connector opening  30  below that of the small portion  40 . 
         [0032]    The flanges  44 ,  48  of the connector openings  30 ,  32  preferably protrude downward from the bottom wall  16 , as shown in  FIGS. 10 and 11 , although this is not required. 
         [0033]    The walls  18 ,  20  of the tub  12  are tapered down to the bottom wall  16 , such that a similar tub  12 ′ can be nested within the tub  12  when empty, as shown in  FIGS. 12 and 13 . This facilitates storage and shipping when empty. 
         [0034]      FIG. 14  is a section view through the tub  12  and tray  14  of  FIG. 1 .  FIG. 14A  is an enlarged view of Area A of  FIG. 14 . The connector  34  has wings  52  protruding in opposite directions from its outer end. The wings  52  are larger than the small portion  40  of the connector opening  30 , but smaller than the large portion  38 . For assembly, the connector  34  is inserted through the large portion  38 . The tub  12  is then slid relative to the tray  14  so that the connector  34  is slid into the small portion  40  and the wings  52  of the connector  34  are interlocked over the flange  44 , thereby retaining the tub  12  to the tray  14 . 
         [0035]      FIG. 14B  is an enlarged view of Area B of  FIG. 14 , showing the engagement of the alignment feature  36  in the alignment opening  32 . The alignment feature  36  can slide within the elongated alignment opening  32  as the tub  12  is slid relative to the tray  14 . The alignment feature  36  and alignment openings  32  align the tub  12  with the tray  14 . 
         [0036]      FIG. 15  is a side view of a storage system  60  including a rack  62  having a plurality of pairs of spaced apart supports or rails  64 . The pairs of rails  64  are arranged in rows and columns. The trays  14  are sized to be supported at opposite sides of the tray  14  by the rails  64 . The trays  14  can be used alone for storing objects, particularly boxed or larger objects, in the rack  62 . Unboxed smaller objects can be placed in tub  12  and tray  14  assemblies. The tub  12  and tray  14  assemblies are supported by the rails  64  by the trays  14 . Because the tray  14  is reinforced sufficiently to support the weight, the tubs  12  need not be reinforced, but can be molded with a single-wall thickness, such as by injection molding, thermoforming, compression molding, rotational molding or other suitable processes. This reduces the cost and weight of the tubs  12 . In particular, since the tubs  12  can have a single-wall thickness without reinforcement ribs, they can be produced economically in low volumes via thermoforming. 
         [0037]    The trays  14  may be formed by injection molding or other suitable process that provides sufficient strength for the trays  14  to be supported at opposite sides by the rails  64 . The storage system  60  can be part of an automated storage and retrieval system, where the trays  14  are handled by automated storage and retrieval equipment. The equipment can be adapted to handle the trays  14  in a similar manner, whether or not the trays  14  have tubs  12  secured thereto. 
         [0038]      FIG. 16  is a bottom perspective view of an alternate tray  14   a , which is identical to the tray  14  in the previous Figures except for two additional features. First, the tray  14   a  further includes ribs forming end stops  56  at the front and rear ends of the tray  14   a . The end stops  56  provide generally perpendicular surfaces for engaging with complementary stops formed at the front and rear ends of the rails  64 . This prevents the trays  14 a from sliding off the front or rear of the rails  64 . The tray  14   a  further includes side ribs  58 , which simply adjust the fit of the tray  14   a  on the rails  64 . The inclusion of the side ribs  58  and the size of the side ribs  58  depends upon the particular rails  64  with which the tray  14   a  is to be used. 
         [0039]      FIG. 17  is a front view, partially broken away, of the tray  14   a  of  FIG. 16  on supports  64   a  similar to those of  FIG. 15 , with the further inclusion of end stops  65 , which engage the end stops  56  on the tray  14   a  to prevent the tray  14   a  from sliding off the front and rear of the rails  64   a.    
         [0040]    Although the examples above illustrate molded-in connectors for securing the tray  14  to the tub  12 , separate connectors, such as a bolt, wire tie, post and cotter pin, etc. could also be used. The tray  14  could include different types of reinforcement members instead of or in addition to the ribs  28 . For example, the tray  14  could be twin-sheet thermoformed and include steel inserts for reinforcement members. 
         [0041]    Although a preferred embodiment of this invention has been disclosed, a worker of ordinary skill in this art would recognize that certain modifications would come within the scope of this invention. For that reason, the following claims should be studied to determine the true scope and content of this invention.
A storage system includes a tray that can be stored on automated storage and retrieval racks. A tub is removably securable to the tray. The tub includes a bottom wall, a pair of opposed side walls and a pair of opposed end walls. The bottom wall of the tub is removably secured to the tray. Thus, some of the trays in the storage system can be provided with tubs for the storage of loose items.