Abstract:
A biodegradable container made of natural fibrous materials includes two shells, each integrally formed and having surfaces which mate with each other to form an enclosure. At least one of the shells includes latching members rotatable about living hinges between a first position, which permits the shells to be coupled to and decoupled from each other, and a second over-center position wherein engagement surfaces of the latching members contact a surface of the other shell to secure the two shells together.

Description:
CROSS-REFERENCED TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     BACKGROUND OF THE INVENTION 
     I. Field of the Invention 
     The present invention relates to biodegradable containers. More specifically, the present invention relates to containers having a first shell member and a second shell member, each made of a natural fibrous material which will quickly and easily biodegrade after use if deposited in a landfill or the like. When used to contain food, the two shells of the container cooperate to form an enclosure and the two shells of the container are latched together to seal food within the container as the food is shipped or prepared. The shell members may also be used as a serving dish as the food is consumed. 
     II. Description of the Prior Art 
     Various types of containers are used by food distributors, grocers and restaurants to package food. All such packaging, however, suffers from one or more deficiencies making them less than ideal for use. Such containers are often made of aluminum, glass or plastic. Sometimes paper products are employed, however, such paper products are often coated with materials designed to make the package more durable and fluid resistance. These coatings also make such packaging slower to biodegrade and more difficult to effectively recycle. Such packages are a major source of litter and trash. 
     Aluminum, glass and plastic are often employed because they are easily formed into a desired shape. However, such packages are expensive to manufacture, particularly those made of plastics derived from oil when oil prices are high. Paper and cardboard packages are not so easily molded and typically require the use of adhesives, inks and coatings which increase costs and exacerbate environmental issues. 
     SUMMARY OF THE INVENTION 
     Containers made in accordance with the present invention are low cost, made from readily renewable or recycled resources, do not require the use of adhesives and are quickly biodegradable and compostable. Such containers may be used for transporting, cooking, and heating and even service of food items. Such cooking can occur in either a microwave oven or a conventional oven set to temperatures as high as 425° F. Thus, containers made in accordance with the present invention are superior in many important respects to the containers of the prior art. 
     Containers made in accordance with the present invention are made of fibrous plant materials such as bamboo, wheat, straw, bagasse or the like. Recycled paper may also be employed provided that the recycled paper is first subjected to processes designed to remove inks, coating chemicals and the like. The materials used to construct the containers are formed into slurry which is then subjected to a molding and cooking process. The molding and cooking process is carried out at high temperatures (in the 350° F. range) and at high press (15 to 20 tons per square inch) to drive out the moisture from the slurry and form the fibers into a suitable shape. Various plant based starch materials may be added in low concentrations (less than 1%) to make the container more oil and moisture resistant. Other additives may also be employed for this purpose. 
     The food containers of the present invention generally comprise first and second shell members. Both are made of a fibrous natural material. The first shell member comprises a base having a top and a bottom, a first continuous side wall having inside and outside surfaces extending between a first end contiguous with the outer edge of the base and a second end. The first shell member also includes a first mating member comprising a contiguous ledge extending between an inner edge proximate the second end of the side wall and an outer edge terminating in a lip extending from the outer edge of the ledge. More specifically, the first mating member is constructed such that a portion of the side wall, the ledge and the lip form a first channel. 
     The second integrally formed shell member comprises a second base having a top and a bottom and a second continuous side wall having inside and outside surfaces extending between a first end contiguous with the second base and a second end. The second integrally formed shell member also includes a second mating member. The second mating member includes a continuous channel defined at least in part by a first flange extending outwardly proximate the second end of the second contiguous side wall, a second flange extending from the first flange in a plurality of latch members. The latch members extend between living hinges joining the latching members to the rest of the second mating member and engagement surfaces. The living hinges permit the latch members to pivoted between first and second positions. When the latching members are in their first position, the first mating member of the first shell member is insertable into and removable from the second channel of the second mating member of the second shell member such that the first and second shell members form an enclosure when so mated. With the first mating member inserted into the second channel of the second mating member, the hinged latching members may be pivoted to their second position causing the engagement surfaces of the latching members to enter the first channel and, upon reaching a second position, the latching members are over-center and the engagement surfaces are in engagement with the outside surface of the side wall of the first shell member The first shell member is thereby latched to the second shell member so the two shell members do not become unintentionally separated from each other. 
     Various other features may be incorporated into the container described above. For example, either the first or the second shell member, or both shell members, may be provided with a plurality of de-nesting lugs such that when a stack of first shell members and a stack of second shell members are provided at a food packaging station, the shell members can be more easily removed from their respective stacks. To make it easier to unlatch the latching members to permit the shell members to be separated and the container to be opened, each latching member may be provided with a gripping tab which is easily gripped by a user between the user&#39;s thumb and forefinger. To increase the rigidity of the latching members, each may be provided with one or more dimples. One or more dimples may also be provided in the base of either the first or second shell members to improve the rigidity of the base. Likewise, one or more ribs may be provided in the side walls of the first or second shell members to improve the rigidity of the side walls. 
     By adopting the principles of the subject invention, containers of various shapes can be made. For example, the base of either the first or second shell member, or both shell members, can have an oval shape, a rectangular shape or many other desired shapes without deviating from the invention. In some configurations, a manufacturer may find it useful to additionally provide the second mating member of the second shell with a first wall projecting outwardly from the second end of the second side wall and a second wall coupling the first wall to the first flange such that the second channel is defined by the second wall, the first flange and the second flange. Further, a third flange, intermediate the living hinges and the second flange, may be provided to ensure appropriate clearance and interaction between the engagement surfaces of the latches with the outer surface of the side wall of the first shell member. 
     These and other attributes of the present invention will become better understood from a review of the drawings provided as a part of this specification together with the detailed description of the invention provided below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a first stackable member used to form a container made in accordance with the subject invention. 
         FIG. 2  is a perspective view of a second stackable member used in conjunction with the stackable member shown in  FIG. 1  to form a container made in accordance with the present invention. 
         FIG. 3  is a perspective view showing the stackable member of  FIG. 1  and the stackable member of  FIG. 2  jointed together to form an enclosed container. 
         FIG. 4  is a top plan view of the stackable member shown in  FIG. 1 . 
         FIG. 5  is a side elevational view of the stackable member shown in  FIG. 1 . 
         FIG. 6  is an end elevational view of the stackable member shown in  FIG. 1 . 
         FIG. 7  is a bottom plan view of the stackable member shown in  FIG. 1 . 
         FIG. 8  is a top plan view of the stackable member shown in  FIG. 2 . 
         FIG. 9  is a side elevational view of the stackable member shown in  FIG. 2 . 
         FIG. 10  is an end elevational view of the stackable member shown in  FIG. 2 . 
         FIG. 11  is a bottom plan view of the stackable member shown in  FIG. 2 . 
         FIG. 12  is a perspective view showing an alternative embodiment of the shell arrangement shown in  FIG. 1 . 
         FIG. 13  is a perspective view showing an alternative embodiment of the shell arrangement shown in  FIG. 2 . 
         FIG. 14  is a schematic representation illustrating a latch in a first position. 
         FIG. 15  is a schematic diagram showing the latch of  FIG. 14  in a second position. 
     
    
    
     DETAILED DESCRIPTION 
     The drawings show a food container  10 . Each food container  10  comprises a first shell member  12  and a second shell member  50 . The shell members are designed so that, at a food packaging station in a processing plant, restaurant, or the like, a stack of first shell members  12  may be provided and a stack of second shell members  50  may also be provided. Workers at the packaging station then employ a shell member  12  and a shell member  50  to create enclosed food containers as shown in  FIG. 3 . One of the shells  12  and  50  serve as the tray and the other serves as the lid which acts as a lid and which acts as a tray is immaterial to the present invention. One of each type of shell member  12  and  50  is employed to create a food container which securely contains food items within the container. 
     As best illustrated in FIGS.  2  and  8 - 11 , the first shell member  12  includes a first base  14  which has a top  16  and a bottom  18 . The first shell member  12  also includes a side wall  20  having an inside surface  22  and an outside surface  24 . The side wall has a first end contiguous with the outer edge of the base  14 . The side wall extends from the first end  26  away from the base to a second end  28 . The first shell member also includes a first mating member  30  as illustrated in FIGS.  2  and  8 - 11 , the first mating member  30  comprises a ledge  32  extending between an inner edge  34  and an outer edge  36 . The inner edge  34  of the ledge  32  is contiguous with the second end of the side wall  28 . The first mating member also has a lip  38  extending from the outer edge  36  of the ledge  32 . As such, a first channel  40  is formed by at least a portion of the side wall  20  near the second end  28  of the side wall  20 , the ledge  32  and the lip  38 .  FIGS. 2 ,  8  and  11  also illustrate de-nesting lugs  42  which assist in removing a first shell member from a stack of such shell members. 
       FIG. 13  shows an alternative embodiment of the first shell member shown in FIGS.  2  and  8 - 11 . In this embodiment, the base has a rectangular shape rather than an oval shape. The base also has a dimple  19  which helps improve the rigidity of the base. Further, a plurality of ribs  25  are provided in the side wall  20  adjacent the second end  28  of the side wall  20  to improve the rigidity of the side wall. 
     The construction of the second shell member  50  is best shown in FIGS.  1  and  4 - 7 . As illustrated, the second shell member  50  includes a second base  52 , having a bottom  53  and a top  54 , and a second continuous side wall  56 . The second side wall  56  has an inside surface  58  and an outside surface  60 . A first end  62  of side wall  56  is contiguous with the outside edge of the base  52 . The side wall  56  extends between this first end  62  and a second end  64 . A second mating member  66  is joined to the second end  64  of the side wall  56 . The second mating member  66  provides a second continuous channel  68  formed at least in part by a first flange  70  and a second flange  72 . The second mating member also has a plurality of latches  74  coupled either directly or indirectly by living hinges  80  to the second flange  72 . The latching members  74  are each shown as extending between a living hinge  80  and engagement surfaces  82 . The latching members  74  may be provided with dimples  76  which help improve the rigidity of the latching members  74 . Gripping tabs  78  may also be provided as shown in  FIGS. 14-15 . As explained in further detail below, the living hinges  80  permit the latching members  74  to be pivoted between a first position shown in  FIGS. 1 ,  3 ,  4 - 7  and  14  and a latched position shown in  FIG. 15 . As illustrated in FIGS.  1  and  4 - 7 , the second mating member  66  may also include a first wall  86  projecting from the second end  64  of the second side wall  56  as well as the second wall  88  extending between the first wall  86  and the first flange  70 . A third flange  90  may also be provided intermediate the living hinges  80  and the second flange  72 . 
       FIG. 12  shows an alternative embodiment of the second shell member  50 . The embodiments of the first and second shell members shown in  FIGS. 12-13  are intended to be used together to form an enclosed container. 
     As illustrated in the drawings, other features may be incorporated into the second shell member  50  without deviating from the invention. Such features could include de-nesting lugs  84 , labeling  92 , dimples  55  in the base as illustrated in  FIG. 12  or ribs in the side wall (not shown). Such ribs might be like the ribs  25  illustrated in  FIG. 13 . 
       FIGS. 3 ,  14  and  15  are provided to better illustrate how shells  12  and  50  work together and provide an enclosed container  10 . With the latching member  74  in their first position as illustrated in  FIGS. 3 and 14 , the first mating member  30  of the first shell member  12  and the second mating member  66  of the second shell member  50  can be mated to each other. Specifically, the ledge  32  of the first shell member  12  may be inserted into the second continuous channel  68  of the second mating member  66 . With the ledge  32  fully seated within the second contiguous channel  68 , the latching members  74  can then be rotated about the living hinges  80  such that the engagement surfaces  82  enter the first channel  40  of the first shell member  12 . Continued rotation of a latching member  74  about its living hinge  80  will cause the latching member  74  to achieve an over-center position, an example which is illustrated in  FIG. 15 , with the engagement surface  82  in contact with the outside  24  of the side wall  20  of the first shell member  12 . In this over center position, the latching members  74  serve to secure the first shell member  12  to the second shell member  50  to form an enclosure. The over-centered position of the latching members  74  and the contact between the engagement surfaces  82  and side wall  20  means a substantial force will have to be applied to return the latching members  74  to the first, unlatched position. Only then can the first shell member  12  and second shell member  50  can be separated from each other. To assist in unlatching the latching members  74 , the latching members can be provided with gripping tabs  78  such as those shown in  FIGS. 14 and 15 . The gripping tabs  78  can be gripped between the thumb and forefinger of the user. 
     The design principles discussed above may be employed to create shell members having other shapes without deviating from the invention. While the drawings illustrate the shell members having a general oval shape in the case of  FIGS. 1-11  and a generally rectangular shape in the case of  FIGS. 12 and 13 , a round shape, a square shape, a triangular shape, a hexagonal shape, or many other shapes may be employed without deviating from the invention. In fact, essentially any geometric shape may be employed without deviating from the invention. Also, while the mating members of the two devices are illustrated as continuous, this is not necessarily the case. Also, while the drawings show either two or four latching members, those skilled in the art will appreciate that a different number of latching members may be employed without deviating from the invention. Still other modifications may be made which embody the present invention. 
     Thus, the present invention is not to be limited to the specific embodiments of the invention described above. The invention is only limited to the subject matter defined by the following claims together with a full range of the equivalents.