Abstract:
The present invention relates to a stackable container for items, such as food, comprising a base and lid with secure sealing mechanisms. Each of the base and lid comprises corresponding three rims and three edges being mateable to provide multiple layers of sealing mechanisms to ensure durable sealing. The lid further comprises a sealing lip for locking the lid onto the base and for providing another layer of sealing. Each of the base and lid further comprises partially planar raised portions and further raised portion around the outer perimeter of the planar raised portions for providing stable stacking mechanism. The lid further comprises a tab for assisting a user to open the lid without spoilage.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a stackable container for storing and transporting items such as food with tight secure sealing mechanism between a container base and detachable lid with a tab for ease of detaching the lid. 
       BACKGROUND OF THE INVENTION 
       [0002]    Containers are used for storing and transporting items such as food for many different commercial and home applications. For commercial application, such as fast food or take-out restaurant, it is important that the containers provide tight and durable sealing mechanisms between container base and detachable lid to ensure and avoid leakage and/or spoilage and to keep away the contents from contamination. While providing secure and durable sealing mechanism, it is also important to provide a way to easily detach or open the lid. Lid can be detached and attached to the base for a number of times and still must protect the contents from spoilage or contamination. It is, yet, important that the container is stably stackable for saving storing space. 
         [0003]    U.S. Pat. No. 6,056,138, entitled “Triple Seal Container,” issued on May 2, 2000, and subsequent U.S. Pat. No. 6,196,404, entitled “Triple Seal Container With Protrusion,” issued on Mar. 6, 2006 both to Chen, disclose a stackable and nestable triple sealed container for storing and transporting items such as food. Even though the structure provides adequate sealing mechanism between a container base and lid, the triple sealing mechanism is not durable enough to prevent breakage. Once the first sealing structure or rim is broke, the item or contents inside the container may easily be contaminated since it only provides two layers. Further more, sealing structure provides an air pocket or space between the base and lid for easing detaching and opening of the lid; however, this structure works negatively and makes the item inside the container easily be contaminated when the rim is broken. Another shortcoming of these inventions is the fact that it does not provide proper support for stacking the assembled containers. It provides a loose stacking mechanism, whereby the assembled containers may be stacked vertically without proper locking mechanism. There are wider room to slide side way, thus it is not suitable for stacking more than a few or transporting stacks of the containers. 
         [0004]    In US Patent Application Publication No. US2003/0057207, entitled “Container with Food Seals,” published on Mar. 27, 2003, Wong teaches an improved sealing mechanism between base and lid of a container, whereby having four sealing structures with two air pockets or air gaps between the base and the lid for maintaining tight sealing while easing effort to detach the lid form the base or to attach the lid to the base. However, not having proper means to assist a user to detach the lid from the base will still cause spoilage. Even worse, liquid may penetrate into these air gaps of the sealing mechanism defined in between the lid and base by filing it up, and, when it happens, makes it even harder to detach the lid from the base. 
         [0005]    It is desirable to provide a container that addresses these aforementioned issues, and the present invention provides solutions to these shortcomings presented by these prior art products. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to a stackable container for items, such as food, comprising a base and lid with secure sealing mechanisms. Each of the base and lid comprises corresponding three rims and three edges being mateable to provide multiple layers of sealing mechanisms to ensure durable sealing. The lid further comprises a sealing lip for locking the lid onto the base and for providing another layer of sealing. Each of the base and lid further comprises partially planar raised portions and further raised portion around the outer perimeter of the planar raised portions for providing stable stacking mechanism. The lid further comprises a tab for easing a user to open the lid without spoilage. 
         [0007]    According to one aspect of the invention, it provides a stackable container, comprising: (i) a base, comprising a generally planar bottom portion; a shape reinforcing structure comprising a curved portion curved upwardly from the perimeter of the bottom portion and a shape reinforcing rim extending outwardly from the upper end of the curved portion; a base sidewall extended upwardly from the outer end of the reinforcing rim of the shape reinforcing structure; a first base rim region extended horizontally and outwardly from the upper end of the base sidewall; a first base sealing edge extended upwardly from the outer end of the first base rim region; a second base rim region extended horizontally and outwardly from the upper end of the first base sealing edge; a second base sealing edge extended upwardly from the outer end of the second base rim region; a third base rim region extended horizontally and outwardly from the upper end of the second base sealing edge; a third base sealing edge extended upwardly from the outer end of the third base rim region; (ii) a lid, comprising: a generally planar lid top portion; a lid sidewall extended downwardly from the perimeter of the lid top portion; a first lid rim region extended horizontally and outwardly from the bottom end of the lid sidewall; a first lid sealing edge extended upwardly from the outer end of the first lid rim region; a second lid rim region extended horizontally and outwardly from the upper end of the first lid sealing edge; a second lid sealing edge extended upwardly from the outer end of the second lid rim region; a third lid rim region extended horizontally and outwardly from the upper end of the second lid sealing edge; a third lid sealing edge extended downwardly from the outer end of the third lid rim region; a sealing lip extended inwardly from the inner bottom end of the third lid sealing edge; and a tab at one section of the perimeter of the third lid sealing edge for providing a means for detaching the lid from the base; and wherein the first base rim and the first lid rim, the first base sealing edge and the first lid sealing edge, the second base rim and the second lid rim, the second base sealing edge and the second lid sealing edge, the third base rim and the third lid rim, the third base sealing edge and the third lid sealing edge correspond and are mateable for providing sealing mechanisms while the lid is attached to the base; and wherein the reinforcing structure reinforces the shapes of the base side wall and the base bottom. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The invention will now be described in more detail with reference to the accompanying drawings, in which: 
           [0009]      FIG. 1  illustrates a side elevation view of the lid and base of a preferred embodiment of the present invention; 
           [0010]      FIG. 2  illustrates a sectional side view of the base of the preferred embodiment of the present invention; 
           [0011]      FIG. 2   a  illustrates a perspective view of the base of the preferred embodiment of the present invention; 
           [0012]      FIG. 3  illustrates a sectional side view of the lid of the container of the preferred embodiment of the present invention; 
           [0013]      FIG. 3   a  illustrates a top view of the lid of the container of the preferred embodiment of the present invention; 
           [0014]      FIG. 3   b  illustrates a perspective top view of the lid of the container of the preferred embodiment of the present invention; 
           [0015]      FIG. 3   c  illustrates a perspective bottom view of the lid of the container of the preferred embodiment of the present invention; 
           [0016]      FIG. 4  illustrates an enlarged cross-sectional side view of the base of the preferred embodiment of the present invention; 
           [0017]      FIG. 5  illustrates an enlarged cross-sectional side view of the lid with the tab of the preferred embodiment of the present invention; 
           [0018]      FIG. 6  illustrates a cross-sectional side view of the lid and base of the preferred embodiment of the present invention, being detached from each other; 
           [0019]      FIG. 6   a  illustrates the enlarged cross-sectional side view of the lid and base of the preferred embodiment of the present invention, being detached from each other; 
           [0020]      FIG. 7  illustrates a cross-sectional side view of the lid and base of the preferred embodiment of the present invention, being attached each other; 
           [0021]      FIG. 7   a  illustrates the enlarged cross-sectional side view of the lid and base of the preferred embodiment of the present invention, being attached each other; 
           [0022]      FIG. 8  illustrates an enlarged cross-sectional side view of the base and lid, about to be stacked one over the other; 
           [0023]      FIG. 9  illustrates the enlarged cross-sectional side view of the base and lid, being stacked one over the other; 
           [0024]      FIG. 10  illustrates an enlarged cross-sectional side view around the center of the base and lid, about to be stacked on each other; 
           [0025]      FIG. 11  illustrates the enlarged cross-sectional side view around the center of the base and lid, being stacked on each other; 
           [0026]      FIG. 12  illustrates a side elevation view of the lid and base being attached; 
           [0027]      FIG. 13  illustrates a side elevation view of the lid and base, where the lid being detached partially from the base; and 
           [0028]      FIG. 14  illustrates a side elevation view of the lid and base, where the lid being substantially detached from the base. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]      FIG. 1  illustrates a side elevation view of lid  2  and base  3  of a container  1 , which is circular in configuration, of a preferred embodiment of the present invention. The lid  2  is attached to the base  3  for sealing the container  1 . A shape reinforcing structure  19 C is located along the side of the bottom portion of the base  3 . 
         [0030]      FIG. 2  illustrates a cross-sectional side view of the base  3  of the container  1 , and  FIG. 2   a  illustrates a perspective view of the base  3  of the container  1  the preferred embodiment of the present invention. The base  3  of the container  1  comprises a generally planar bottom base portion  19 . The bottom base portion  19  further comprises a partially planar raised central portion  16 , surrounded by a convex or raised base portion  17 , raised slightly above the raised central portion  16 . In the preferred embodiment of the present invention, the partially planar raised central portion  16  is circular shape, equally distanced from the edge of the bottom base portion  19 , and the raised base portion  17  is continuously circular shape along the outer perimeter of the raised central portion  16 . One purpose of this raised base portion  17  is to provide a fitting mechanism so that, by placing the base  3  onto a corresponding structure (see  FIG. 3 ) on the lid  2 , it provides a stable and solid stacking mechanism. 
         [0031]    The shape reinforcing structure  19 C is extended out and curved upwardly from the perimeter of the bottom base portion  19  of the base  3 . Then, a base sidewall  18  is extended upwardly from the upper end of the shape reinforcing structure  19 C. As it can also be seen in  FIG. 4 , a first base rim region  10  is extended horizontally and outwardly from the upper end of the base sidewall  18 . Then, a first base sealing edge  11  extends upwardly from the outer end of the base rim region  10 . Then, a second base rim region  12  extends further horizontally and outwardly from the upper end of the first base sealing edge  11 , and a second base sealing edge  13  extends upwardly from the outer end of the second base rim region  12 . A third base rim region  14  is extended horizontally and outwardly from the upper end of the second base sealing edge  13 , and a third base sealing edge  15  is extended downwardly from the outer end of the third base rim region  14 . 
         [0032]      FIG. 3  illustrates a sectional side view of the lid  2  of the container  1  of the preferred embodiment of the present invention, where  FIG. 3   a  illustrates a top view of the lid  2  of the container  1 ,  FIG. 3   b  illustrates a perspective top view of the lid  2  of the container  1 , and  FIG. 3   c  illustrates a perspective bottom view of the lid  2  of the container  1  of the preferred embodiment of the present invention. The lid  2  comprises a lid top portion  29  comprising partially planner raised central portion  26  surrounded by a convex or raised lid portion  27 . In the preferred embodiment of the present invention, the partially planar raised central portion  26  is circular in shape, equally distanced from the edge of the lid top portion  29 , and the raised lid portion  27  is continuously circular in shape around the outer perimeter of the raised central portion  26 . It is noted that at least one of raised base or lid portion  17  or  27 , respectively, shall be continuously raised along the outer perimeter of the raised center portions  16  or  26 , respectively. In this case, the other one of the raised portions  17  and  27  may be non-continuous. If a certain orientation or alignment of the containers  1  while stacking is important for a particular application, this raised portions  17  and  27  may define a keying structure, where the containers can only be settled and fitted when the containers are aligned in a particular direction. There is a void  33  around the center of raised central portion  26 . The outer end of the lid top portion  29 , the lid  2  further comprises a raised wall portion  30 , before a lid sidewall portion  28  extending downwardly. As it can also be seen in  FIG. 5 , at the bottom end of the lid sidewall portion  28 , a first lid rim region  20  is extended horizontally and outwardly, and a first lid sealing edge  21  is extended upwardly from the outer end of the first lid rim region  20 . 
         [0033]    Then, a second lid rim region  22  extends further horizontally and outwardly from the first lid sealing edge  21 , and a second lid sealing edge  23  extends upwardly from the outer end of the second lid rim region  22 . Further, a third lid rim region  24  is extended horizontally and outwardly from the second lid sealing edge  23 , and a third lid sealing edge  25  is extended downwardly from the outer end of the third lid rim region  24 . At the end of the third lid sealing edge  25 , a sealing lip  32  extended inwardly to provide a locking mechanism for locking or latching to the base  3 . The lid  2  further comprises a tab  31  for easing a user to detach the lid  2  by pulling the tap  31  and pulling it outwardly and upwardly. 
         [0034]      FIG. 4  illustrates an enlarged cross-sectional side view of the base  3  of the preferred embodiment of the present invention. In the preferred embodiment of the present invention, the shape reinforcing structure  19 C comprising curvature portion curved upwardly from the perimeter of the bottom base portion  19  and a shape reinforcing rim  19 D extending outwardly from the upper end of curved portion of the shape reinforcing structure  19 C. Then, the side base wall  18  extends upwardly from the outer end of the reinforcing rim  19 D of the shape reinforcing structure  19 C. The width of the shape reinforcing rim  19 D may be about 0.6 mm for a food container application. However, the width of the shape reinforcing rim  19 D depends on thickness of the side base wall  18 , thickness of the bottom base portion  19 , or combination of two. The shape reinforcing rim  19 D reinforces the shape of the base bottom portion  19 , the curvature of the shape reinforcing structure  19 C, and shape of the side base wall  18  in the case of containing some contents with high temperature or heavier items that may be sufficient to cause deforming the shape of the container  1 . And,  FIG. 5  illustrates an enlarged cross-sectional side view of the lid  2  with the tab  31  of the preferred embodiment of the present invention. 
         [0035]      FIG. 6  illustrates a cross-sectional side view of the lid  2  and base  3  of the container  1 , while the lid  2  and base  3  are detached from each other, and  FIG. 6   a  illustrates the enlarged view of  FIG. 6  or the enlarged cross-sectional side view of the lid  2  and base  3  of the container  1  of the preferred embodiment of the present invention, while  FIG. 7  illustrates a cross-sectional side view of the lid  2  and base  3  being attached each other, and  FIG. 7   a  illustrates an enlarged cross-sectional side view of  FIG. 7  or the container  1  where the lid  2  attached to the base  3  of the preferred embodiment of the present invention. To attach the lid  2  onto the base  3 , from the position shown in  FIG. 6  to  FIG. 7 , the lid  2  is pressed downwardly onto the base  3 . The first rim region  20  of the lid  2  aligned with the first rim region  10  of the base  3 ; so that the first sealing edge  21  of the lid  2  aligns with the first sealing edge  10  of the base  3 ; the second rim region  22  with the second rim region  12 ; the second sealing edge  23  with the second sealing edge  13 ; the third rim  24  with the third rim  14 ; and the third sealing edge  25  with the third sealing edge  15 . While applying the downward force to the lid  2  onto the base  3 , the sealing lip  32  will be pushed and flexed outwardly, sliding along the third sealing edge  15  of the base  3 , then flexed back inwardly to the end of the third sealing edge  15  to complete sealing. In the preferred embodiment of the present invention, the sealing lip  32  is half circular in shape from the cross-sectional side view, and the radius thereof is sufficiently large to provide a first sealing mechanism formed between the sealing lip  32  and the bottom end of the third sealing edge  15  of the base  3 . It is noted that lengths and structure of the first base rim region  10 , first base sealing edge  11 , second base rim region  12 , second base sealing edge  13 , third base rim region  14 , third base sealing edge  15  of the base  3  correspond to first horizontally extended rim region  20 , first sealing edge  21 , second rim region  22 , second sealing edge  23 , third base rim region  24 , and third base sealing edge  25  of the lid  2 , respectively, so that it provides tight and secure sealing mechanism between the base  3  and the lid  2 . 
         [0036]    The present invention provides at least seven distinct sealing mechanisms. From inside the container  1 , the first sealing mechanism is defined by the first rims  10  and  20 . The second sealing is defined by the first sealing edges  11  and  21 ; third sealing defined by the second rims  12  and  22 ; the forth sealing defined by the second sealing edges  13  and  23 ; the fifth sealing defined by the third rims  14  and  24 ; sixth sealing defined by the third sealing edges  15  and  25 ; the seventh sealing defined by the end of the third edge  15  and the sealing lip  32 . 
         [0037]      FIG. 8  illustrates an enlarged cross-sectional side view of the base  3  and lid  2 , where the base  3  is about to be stacked on the top of the lid  2 , and  FIG. 9  illustrates the enlarged cross-sectional side view of the base  3  and lid  2 , where the base  3  is stacked on the top of the lid  2 . Note that shape of the base bottom  19 , including the partially planar raised central portion  16  and raised portion  17  corresponds to the shape or construction of the upper surface of the lid top portion  29 , including partially planar raised central portion  26  and raised portion  27  to provide a sufficient fitting for stable and solid stacking mechanism. The curved end of base bottom or shape reinforcing structure  19 C of the base  3  and the raised wall portion of the lid  2  forms an air gap  40  to avoid the base  3  and lid  2  being stick onto one another for easing un-stacking the containers  1 . 
         [0038]      FIG. 10  illustrates an enlarged cross-sectional side view around the center of the base  2  and lid  3 , where the base  2  is about to be stacked on the top of the lid  2 , and  FIG. 11  illustrates the enlarged cross-sectional side view around the center of the base  2  and lid  3 , where the base  3  is stacked on the top of the lid  2 . Note that the construction of the bottom  19  of the base  3 , including partially planar raised central portion  16  and raised portion  17 , corresponds to the construction of the top  29  of the lid  2 , including partially planar raised central portion  26  and raised portion  27 , so that they fit each other while the base  3  is stacked on the top of the lid  2 . It is also noted that a void  33  of the lid  2  and partially planar raised central portion  16  of the base  3  defines an air gap  41  for preventing the lid  2  and base  3  being stick onto one another and easing un-stacking the stacked containers  1 . 
         [0039]      FIGS. 12 ,  13  and  14  illustrate a series of side views of the lid  2  and base  3 , where  FIG. 12  shows that the lid  2  and base  3  are attached to one another,  FIG. 13  shows that the lid  2  is detached partially from the base  3 , and  FIG. 14  shows that the lid  2  is substantially detached from the base  3 . A user pulls the tab  31  outwardly to disengage the sealing lip  32  from the third base sealing edge  15  and to create an air gap (not shown) between rims and edges of the base  3  and lid  2  of the container, and, then, upwardly to further disengage the lid  2  from the base  3 . 
         [0040]    With respect to the above description then, it is to be realized that the optimum dimensional relationships for the parts of the invention, to include variations in size, materials, shape, form, function and manner of operation, assembly and use, are deemed readily apparent and obvious to one skilled in the art, and all equivalent relationships to those illustrated in the drawings and described in the specification are intended to be encompassed by the present invention. For example, applying the spirits and principles of the invention into a container in a rectangular shape is readily apparent and obvious to one ordinary skilled in the art. 
         [0041]    Therefore, it is to be understood that the embodiment shown and described herein is merely illustration of the principles of this invention and that various modifications may be implemented by those skilled in the art without departing from the spirit and scope of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention. For example, although the embodiment shown herewith is circular in configuration, the container  1  can be rectangular, square, oval, oblong, or any other shape.