Abstract:
A sealed, locked, and reopenable cup and lid assembly comprises a cup, a resilient circular lid, circumferentially spaced and rotationally alignable interrupted portions and at least one tab. The resilient circular lid is sized to be inserted in a mouth of the cup and to fit in a locking groove of the cup. The resilient circular lid is permitted to be removed upon alignment of interrupted portions in the locking groove and a peripheral lip of the circular lid.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119(e) of the co-pending U.S. Provisional Application No. 60/774,292, filed on Feb. 17, 2006 and entitled “SNAP LOCK CONTAINER WITH LID ROTATION TAB.” 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to closable and reopenable plastic containers, and, more particularly, to such containers having a separate cup and lid which, when attached to close the container, provide a continuous seal and locked engagement, but having manually engageable tabs on the lid to facilitate relative rotational movement between the two for opening. 
         [0003]    U.S. Pat. No. 6,688,487 describes a sealed, locked and reopenable cup and lid assembly utilizing a cup that has an open circular mouth defined by an upper edge, a radially inwardly opening locking groove below the upper edge, and a resilient circular lid that is sized to be inserted into the open mouth of the cup and which has an outer peripheral lip that is received with a snap fit in the locking groove in the cup. The locking groove and the peripheral lip include interrupted portions that are circumferentially spaced and rotationally alignable to permit removal of the lid. 
         [0004]    The foregoing prior art cup and lid are also provided, respectively, with a frustoconical inner wall portion that extends downwardly and diverges outwardly from the locking groove and a frustoconical sealing wall that extends downwardly and diverges outwardly from the peripheral lip. The frustoconical inner wall portion of the cup is engaged by the frustoconical sealing wall of the lid as the lid is snapped into the locking groove to provide a liquid-tight seal. 
         [0005]    When applying the foregoing technology to non-liquid or non-beverage containers, a number of problems have been encountered. First of all, the larger diameter of some containers, such as may be used at point-of-sale or for home storage and reuse, make it difficult for the user to grip the container body and rotate the lid to align the interrupted portions in the locking groove and lip to permit reopening. In addition, the liquid tight seal provided by engagement between the frustoconical inner wall of the cup and the frustoconical sealing wall of the lid may be so tight as to inhibit relative rotational movement between the lid and cup when grasped by the user. Furthermore, when the container and lid are used for dry or semi-solid storage, a dust-tight seal may be adequate and a liquid-tight seal is not necessary. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with the present invention, a sealed, locked and reopenable container and lid assembly of a circular configuration has a lid with a peripheral outwardly extending tab that may be grasped by the user to aid in opening the container. The lid tab assists in turning the lid with respect to the container when unlocking the lid from the container or for locking or relocking when the container is closed. The tab provides the user with the ability to provide additional leverage or torque to rotate the lid, the rotation of which may be made more difficult because of the high friction seal between the frustoconical wall portion of the cup and the frustoconical sealing wall of the lid. The lid tab also assists the user in breaking the seal between the lid and the container by using the tab to lift the lid. 
         [0007]    The mouth of the container may also be provided with a similar outwardly extending lip or lips to assist the user in holding onto the container when its diameter is too large to permit the container wall to be easily grasped. When it is necessary to rotate the lid with respect to the container, when locking or unlocking, the tab or tabs assist the user by providing additional leverage for permitting the user to apply more torque and to stabilize the container against movement. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a top perspective view of a container of the present invention. 
           [0009]      FIG. 2  is a side elevation view of the container of  FIG. 1   
           [0010]      FIG. 3  is a top plan view of the container shown in  FIG. 1 . 
           [0011]      FIG. 4  is a vertical section through the container of  FIG. 1 . 
           [0012]      FIG. 5  is a bottom perspective view a lid for use with the container shown in  FIGS. 1-4 . 
           [0013]      FIG. 6  is a side elevation view of the lid shown in  FIG. 5   
           [0014]      FIG. 7  is a top plan view of the lid. 
           [0015]      FIG. 8  is a sectional view taken on line A-A of  FIG. 7 . 
           [0016]      FIG. 9  is a photo of the assembled container and lid of  FIGS. 1-8 . 
           [0017]      FIG. 10  is another photo of the assembled container and lid of  FIGS. 1-8 . 
           [0018]      FIG. 11  is a top plan view of an assembled container and lid of an alternate embodiment of the invention. 
           [0019]      FIG. 12  is a side elevation view of the assembled container and lid of  FIG. 12 . 
           [0020]      FIG. 13  is an enlarged partial sectional view taken on line A-A of  FIG. 11 . 
           [0021]      FIG. 14  is an enlarged partial sectional view taken on line B-B of  FIG. 11 . 
           [0022]      FIG. 15  is a photo of the assembled container and lid of  FIGS. 11-14 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0023]    A perspective view of a container  10  forming a part of the assembly of the present invention is shown in  FIG. 1 . A lid  11  for enclosing the container is shown in a perspective view in  FIG. 5 . The container  10  and lid  11  are preferably thermoformed of a suitable plastic material, but other molding methods may also be used. Any of the well known and commonly used thermoforming plastic resins may be utilized, including PET and polystyrenes, among others. The container  10  and lid  11  are thus of a type commonly used in the food service industries and at home for the storage of food products. The products for which the container and lid may be used may include liquid, semi-solid and solid foods. 
         [0024]    The container  10  includes a lower body  12  which, in the embodiment shown, has a smooth frustoconical shape. The container has an open circular mouth  13  defined by a rounded inner rim  14  from which extends outwardly an undulating edge  15 . In the embodiment shown, the outer edge  15  defines four circumferentially spaced tabs  16 . 
         [0025]    The rim  14  defines the upper edge of a cylindrical and generally vertical inner first wall portion  17  which is joined at its lower edge by an annular generally horizontal second wall portion  18  that extends radially inwardly from the vertical first wall portion  17 . The vertical first wall portion  17  is also provided with a series of circumferentially spaced locking protrusions  20 , of which there are four in number and each of which slopes inwardly and downwardly from the rim  14  to provide lead-ins  21  to facilitate attachment of the lid  11  as will be described below. Each of the locking protrusions  20  has a flat lower surface that is spaced vertically above the second horizontal wall portion  18  to define therewith a locking groove  22  for the lid  11 . 
         [0026]    Joined integrally to the inner edge of the second wall portion  18  and extending downwardly and slightly outwardly therefrom is an inner third wall portion  23  having a slight frustoconical shape with a draft angle or angle of divergence from the vertical of, for example, 1.5°. A small annular shoulder  24  separates the third wall portion  23  from the container body  12 . 
         [0027]    Referring also to  FIGS. 5-8 , the lid  10  has a generally flat central body  25  and a compound peripheral lip  26  that provides locking engagement with the mouth  13  of the container and, optionally, to also provide a tight seal. Most of the entire circumference of the lip  26  of the lid comprises a generally flat upper lip surface  27 . However, the upper lip surface  27  includes at least one integral tab  28  which extends radially upwardly and outwardly from the lip  26 . The tab  28  includes a generally vertical connection piece  30  and a generally horizontal tab body  31 , the latter configured and positioned to be easily grasped between the thumb and finger of a user. 
         [0028]    The lip  26  also includes a horizontal lower lip surface  32  that is connected to the upper lip surface  27  by a generally vertical intermediate surface  33 . The inner edge of the horizontal lower lip surface  32  is joined to a generally vertical, but slightly frustoconical sealing wall  34 , that diverges downwardly and outwardly at a small draft angle of, for example, 3°. The lower edge of the sealing wall  34  is integrally connected to the lid body  25 . To secure the lid  11  to the container  10 , the lid is placed in the mouth  13  and pressed vertically downward. The compound peripheral lip  26  has a diameter greater than the minimum diameter defined by the locking protrusions  20  that extend inwardly from the upper first wall portion  17  of the container  10 . Downward movement of the lid will cause resilient inward deflection of the upper lip surface  27  as it passes over the lead-in surfaces  21  of the locking protrusions  20 . As the outermost edge of the upper lip surface  27  reaches the lower edges of the locking protrusions  20 , the entire lip  26  snaps into the locking groove  22  which is dimensioned to cause the upper lip surface  27  to bear on the undersurfaces of the protrusions. Correspondingly, the lower lip surface  32  bears on the horizontal second wall portion  18  of the container  10 . 
         [0029]    As the lip  26  of the lid  11  moves downwardly into the container mouth  13 , the third wall portion  23  of the container is engaged by the sealing wall  34  on the lid. When the lip has snapped into the locking groove  22  under the locking protrusions  20 , a seal is simultaneously formed between the third wall portion  23  and the sealing wall  34 . 
         [0030]    To permit the lid  11  to be removed from the container  10 , an unlocking and reopening feature is also provided. The peripheral lip  27  of the lid  11  is provided with recesses  35  that are spaced circumferentially and dimensioned to correspond to the position and size of the locking protrusions  20  of the container. The recesses  35  extend into the lower horizontal lip surface  32 . When the recesses  35  are rotationally aligned with the locking protrusions  20 , as by the user holding the container in one hand and grasping and turning the lid tab  28 , the lid may be lifted by the tab  28  and removed from the container. Once the recesses  35  are aligned with the locking protrusions  20 , only the interference fit between the frustoconical sealing surfaces  23  and  34  need be overcome. Relative rotation between the lid  11  and the container  10  may also be facilitated by the user grasping one of the container tabs  16  to hold the container while the lid tab  28  is grasped to rotate the lid to the opening position. Regardless of where the lid tab  28  is positioned on the container in the locked position, one of the four container tabs  16  will be conveniently located to permit the user to apply the most advantageous leverage for rotating the lid. 
         [0031]      FIGS. 9 and 10  show perspective views of a locked assembly of a container  10  and lid  11 . 
         [0032]    Referring now to  FIGS. 11-15 , a modified embodiment of the invention is shown. The container  36  and lid  37  are attached in the same manner as in the previously described embodiment. In this embodiment, the container body  38  is generally similar to the previously described embodiment. The mouth  40  of the container similarly has a compound rim  41 , however, the outer peripheral edge  42  has, in plan, a generally square shape with large radiused corners  43 . The corners  43  extend outwardly from the container body to provide tabs that perform the same function as the container tabs  16  of the previously described embodiment. In other words, one of the radiused corners  43  may be grasped by the user to facilitate removal of the lid  37 . 
         [0033]    The container rim  41  includes an inner generally vertical first wall portion  44  joined at its lower edge by an annular second wall portion  45  that extends radially inwardly from the vertical first wall portion. As in the previously described embodiment, the vertical first wall portion  44  also includes a series of circumferentially spaced locking protrusions  46 . The locking protrusions  46  are provided with tapered lead-ins  47 . The undersurfaces of the locking protrusions and the second wall portion  45 , interconnected by the first wall portion  44 , provide a locking groove for the lip  48  of the lid  37 . Furthermore, downwardly divergent third wall portion  50  in the container  36  and a frustoconical wall portion  51  on the lid  37  interengage to provide a sealing feature similar to that of the previously described embodiment. 
         [0034]    The lid  37  has a flat body  52  and a stepped lip  48  as in the previously described embodiment. The lip  48  includes an upper lip surface  54  having a circular outer edge that extends nearly the entire circumference of the lid. However, the upper lip surface  54  is interrupted by a finger tab  55  that is spaced vertically above the container rim  41  and connected thereto with an upwardly divergent connection piece  56 . 
         [0035]    The lip  48  of the lid  37  includes a generally cylindrical intermediate surface  57  which connects at its lower edge to a lower lip surface  58 , and which together form the compound lip that enters and is held in the locking groove  49 . Recessed portions  53  in the lip  48  may be rotationally aligned with the locking protrusions  46  for lid removal as previously described. 
         [0036]    The attachment of the lid  37  to the container  36  and its rotation relative thereto by utilizing the tab  55  is functionally the same as in the previously described embodiment. It should be noted, however, that by changing very slightly certain of the dimensions of the interengaging container and lid portions, such as the diameter of one or the other of the third wall portion  50  and sealing wall portion  51  or their respective draft angles, the seal between their abutting faces may be varied considerably or even eliminated. Thus, for liquid contents, it may be desirable to have a very tight interference fit to provide a liquid-tight seal. In this case, the rotational tab  55  on the lid  37  and the radiused corners  43  on the rim of the container may be especially useful in facilitation rotation and in lifting the lid from the container. On the other hand, if it is only desired to keep the contents dust-free, a liquid-tight seal may be unnecessary and the interference fit between sealing surfaces  50  and  51  may be reduced considerably.