Patent Publication Number: US-8534492-B2

Title: Container with air-tight lid

Description:
BACKGROUND 
     Containers such as bowls for food items and the like have sometimes been provided with lids. However, the container/lid combinations have typically been susceptible to leakage, or difficulties in securing the lid to the container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the disclosure will readily be appreciated by persons skilled in the art from the following detailed description when read in conjunction with the drawing wherein: 
         FIG. 1  is a front view of an exemplary embodiment of a bowl with a lid in a secured position. 
         FIG. 2  is an isometric view of the bowl of  FIG. 1 . 
         FIG. 3  is an front elevation exploded view of the bowl and lid of  FIG. 1 , showing a seal member.  FIG. 3A  is an isometric view of an exemplary embodiment of the seal member. 
         FIG. 4  is a front elevation view of the lid of  FIG. 1 , shown with the latches in an extended position 
         FIG. 5  is a front elevation view of the lid of  FIG. 1 , shown with the latches in a latch position. 
         FIG. 6A  is a bottom view of the lid as shown in  FIG. 5 .  FIG. 6B  is a cutaway view, taken along line  6 B- 6 B of  FIG. 6A . 
         FIG. 7A  is a top view of the bowl and lid assembly of  FIG. 1 .  FIG. 7B  is a cross-sectional view taken along line  7 B- 7 B of  FIG. 7A .  FIG. 7C  is a cross-sectional view taken along line  7 C- 7 C of  FIG. 7A . 
         FIGS. 8A ,  8 B and  8 C illustrate stacking of like bowls, showing two like bowls in a stacked relationship. 
         FIGS. 9 ,  9 A,  9 B,  9 C,  9 D and  9 E illustrate an alternate embodiment of a lid for attachment to a container. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description and in the several figures of the drawing, like elements are identified with like reference numerals. 
     An exemplary embodiment of this invention includes a plastic container with an air-tight lid system, suitable for storage of food items, for example. The lid system includes a plastic lid including a cover portion and a plurality of lid latches connected to the lid cover portion by living hinges. A seal gasket is fitted into an inner seal groove or channel formed in a lid periphery. The latches are configured for movement between extended positions in which the lid is removable from the bowl, and a latching position in which latch features engage the bowl to secure the lid and gasket in a sealed position on the bowl. 
       FIGS. 1-8C  illustrate an exemplary embodiment of the container with air-tight lid system, in which the combination is designated generally as  10 . The container  50  in this embodiment takes the form of a bowl having a generally concave shape with an open top. The container  50  includes bowl portion  60  and a top peripheral lip portion  70 . The bowl portion  60  defines an interior bowl volume  62 . The top peripheral lip portion  70  includes a flat, planar annular rim portion  72  extending from the top edge of the bowl portion, with a distal edge of the rim portion  72  terminating in a downwardly extending wall portion  74  having a lower edge  74 A. The wall portion  74  is spaced from the upper region of the bowl portion, defining a channel between the wall portion and the adjacent exterior surface of the bowl portion. 
     A plurality of spaced rib portions  76  are formed between the bowl portion and the wall portion  74  to provide strengthening features. In an exemplary embodiment, the rib portions are spaced at 45 degree intervals about the periphery of the bowl portion. Another function of the rib portions  76  is to provide nesting stops for like bowls for secure, flat/uniform stacking of vessels. Stacking of like bowls is illustrated in  FIGS. 8A-8C , which shows like bowls  50  and  50 ′ in a stacked relationship. The rib portions  74  include in this embodiment generally flat bottom surfaces  74 A, and with the like bowls in a stacked relationship, the flat bottom surface  74 A of an upper bowl rests on the flat rim surface  72  of the lower bowl. 
     Interference between the rib portions  74  and the lid latches is prevented by latch relief regions  74 B ( FIG. 7B ) formed between the ribs and the wall portion  74 . 
     The depth of the wall portion, i.e. the vertical distance from the rim to the edge  74 A, may be selected in coordination with the latch configuration and dimensions. 
       FIG. 3  shows the bowl and lid system  10  in exploded view, including the seal member  40 , which is held in a channel formed in the lid  100 , and is brought into compression between the lid and the inner edge of the bowl rim surface  72  when the lid latches are closed. Further illustrated in  FIG. 3A , the seal member  40  may be an extruded or molded elastomeric member. In an exemplary embodiment, the seal member is an injection-molded unitary part, and of solid cross section. The seal member may be made of a silicon or TPE (thermoplastic elastomer). The seal member  40 , in the case of a round bowl configuration, is sized to have a diameter of its inner wall generally equivalent to the diameter of the inner edge of the flat peripheral surface  72 . The thickness dimension of the seal member in an exemplary embodiment is selected to optimize the tradeoff of moldability of the seal, sufficient thickness to allow appropriate compression properties for the latch seal arrangement, and to provide appropriate rigidity when handling of the seal as it is applied and removed from the lids. 
     The lid  100  includes a cover surface  110  which is sized to extend over the open top of the bowl when the lid is attached to the bowl  50 . The cover surface  110  is generally planar in this embodiment, and is connected to a lid peripheral portion  120  by a beveled or angled surface portion  112 , providing a shallow dome structure. The beveled surface portion facilitates stacking of similarly sized lids  100 . 
     The underside of the lid peripheral portion  120  defines two peripheral channels or grooves, an inner channel in which the seal member is received, and an outer channel. Thus, as for example illustrated in  FIGS. 6A and 6B , the lid peripheral portion  120  includes a generally annular web portion  122  connected to the edge of the beveled surface portion  112 . Intermediate and outer peripheral walls or ribs  124 A and  124 B extend downwardly and, with the web portion  122 , defines the inner channel  126 A and the outer channel  126 B. The seal member  40  is positioned in the inner channel  126 A. A function of the outer channel  126 B is to provide rigidity and bridge the gap between the inner channel  126 A and the outer edge of the lid. 
     The lid peripheral portion  120  further includes an inner wall or rib portion  128  which protrudes downwardly, and has an outer diameter dimension sized in cooperation with the inner diameter of the top edge of the bowl portion  60  of the container  50 , such that the inner wall portion  128  fits into the bowl portion (see  FIGS. 7B and 7C ) and provides a lid alignment feature or rib, to align the lid properly with the bowl as the lid is being installed onto the bowl. The rib portion  128 , in an exemplary embodiment, is designed to fit around the upwardly projecting lid cover surface  110 , so that stacking of like lids is secure and nesting occurs reducing the height requirement for stacks of like lids. The angle on the rib portion  128  provides a lead-in for the lid-to-bowl alignment. The fit of the rib portion and bowl in an exemplary embodiment is sufficiently tight for proper latch alignment to occur but does not provide sealing. 
     The latches  130  are connected to the lid peripheral portion  120  at the bottom edge of the outer peripheral wall  124 B ( FIG. 6B ) distal from the annular web portion  122  by living hinges  140 , so that the latches may be rotated about the hinges  140  to the downwardly positioned latched position shown in  FIGS. 1 ,  5  and  6 B, for example, and upwardly positioned latch release positions such as the position shown in  FIG. 4 , for example. As such, it will be appreciated that in an exemplary embodiment, the lid is a unitary structure, fabricated from a plastic material such as polypropylene by injection molding. In an exemplary embodiment, the latches have a substantial width to provide robust latching to the bowl. In one example the latches subtend an angle in a range of 30 to 45 degrees relative to the center of the lid. In this example, while the living hinge  140  is a linear hinge, the lid peripheral portion  120  includes a protruding transition web region  142  for each latch, connecting the living hinge  140  to the edge of the lid peripheral region. To provide increased support to the linear hinges, the transition web regions extend angularly from each hinge end to the edge of the lid peripheral region, as shown in  FIG. 6A , for example. Thus, while the lid peripheral region has a generally circular configuration in this embodiment, the transition web regions protrude from the generally circular configuration to allow wider latches, and thus enhanced latching force, while supporting the living hinges. 
     The latches  130  each include a hook or barb region  132  intermediate the hinge and the latch tip. The hook region  132  is configured to engage the lower edge  74 A of the bowl wall  74  in a latch position. The hook or barb region  132 , due to the width of the latch, includes a curved inwardly facing surface  132 A ( FIG. 6A ), to generally match the curvature of the bowl edge, as visible in  FIG. 6A , for example. The width of the hook region and its matching curvature enhance the latching force provided by the latch. 
     While the exemplary embodiment illustrated in  FIGS. 1-7C  employs four latches  130  at uniform spacing around the lid periphery, other embodiments may employ a fewer or a greater number of latches. For a container with dimensions of 7 inch diameter at the open top of the container, and a height of 3.2 inch, a wall  74  height of 0.4 inch, with a flat surface  72  width of 0.4 inch, and a seal width of 0.125 inch and height of 0.274 inch, four latches having a width of 2.75 inch and height of 1.25 inch each has been found suitable. 
       FIGS. 9-9E  illustrate an alternate embodiment of a lid  100 ′ for attachment to the container  50 . The alternate lid embodiment is similar to lid  100 , but includes a latch cutout or window  146  in each of the latches  130 ′. In this embodiment, the cutout extends heightwise when in a latched condition from about the height or level of the bowl rim to below the bottom surface  74 A of the outer wall  74 . The width of the cutout may depend on the diameter of the container, but in an exemplary embodiment for a container diameter of 7 inches and an outer wall depth of 0.4 inch, a cutout 0.2 inch high by 1 inch wide is satisfactory. 
     The cutout  146  allows for the rotation point of the latch (the latch or barb region of the latch to move inward. This feature allows hinge  140  to move into vertical alignment with  74 A of the container, and reduces the negative effect caused by round vessels, where the latch hinge tends to be moved away from the lid and vessel. 
     The cutout or window feature could be exaggerated in other embodiments not shown by increasing the size of the cutout in the latch. 
     Although the foregoing has been a description and illustration of specific embodiments of the invention, various modifications and changes thereto can be made by persons skilled in the art without departing from the scope and spirit of the invention.