Abstract:
The present invention relates generally to plastic containers which can be used for holding, organizing and securing optical disks including CDs, DVDs, mini CDs, and mini DVDs. Features of the apparatus serve to prevent dirt, dust, water, and other debris from entering the containers. Additional features include a stackable design that aids in organization and storage of a plurality of optical disks or other items. Some embodiments of the present invention have a hinged top and bottom. Additional features of some embodiments include ears allowing the container to be attached to a travel device such as a notebook or binder.

Description:
PRIORITY CLAIM 
   This application claims the benefit of U.S. Provisional Application No. 60/330,223 filed Oct. 16, 2001 entitled “Stackable Plastic Containers,” the entire contents of which is hereby expressly incorporated by reference. 

   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to plastic containers for holding, organizing and securing optical disks. 
   2. Description of the Related Art 
   Stackable containers have long been used in the prior art. Typically, containers with stackable properties use threaded male/female sections. The top female section is constructed with internal threads. This section screws into the male bottom section. The male bottom section is constructed with an additional attached molded female section which is also a container. Several such containers can be combined to form a stack of containers. These types of threaded containers are generally more expensive and much slower to manufacture than “snap-together” containers. Because threaded containers also allow dirt and debris in the threads, threaded containers often have difficulty closing properly. Further, threaded containers are frequently much taller in height due to the minimum amount of threads needed to make the container screw together. Indeed, most threaded containers are at least about 0.375 inches high. Threaded containers also require stiffer plastic and thicker side walls because of the threaded side wall pressures. Soft plastics like polypropylene are typically not suitable for threaded containers because the threads may strip if over-tightened. 
   Other containers that use stacking properties are found in the houseware industry. A houseware stackable containers have covers with ribs that match the bottoms of matching containers. The raised rib around the perimeter of a container&#39;s lid is larger than the bottom of the container to be stacked on the cover. The bottom nests into the lid. This container relies on gravity and internal weight to stay together. If the containers are dropped, the stack of containers simply falls apart. 
   Other containers in the prior art use a “friction fit” lid and bottom. This type of container has a lid which has a raised center section approximately 0.050 inches per side smaller than the outside diameter of the container. This area is raised 0.030 inches to 0.050 inches from the rest of the lid. The bottom of the container which forms the container has a ring a few thousands smaller than the top raised center section. The bottom will fit so that the friction that is created will hold the next container set next to the previous container set. Typically, a container set is made of one top and one bottom. A stack is made up of two or more container sets stacked on each other. This method of stacking containers is expensive because of the extra parts required to manufacture the container. 
   SUMMARY OF THE INVENTION 
   In one aspect, the current invention provides an improved plastic container for holding, organizing and/or securing optical disks, or like contents, that is easy and inexpensive to manufacture and which can be used as a single disk holder or in stackable format, in which an internal cavity is formed by a male/female (top and bottom) container. Preferably, each container is only as thick as the required thickness of the item to be enclosed, such as, for example, an optical disk. The containers may be secured by closing, locking, and/or sealing mechanisms. In a preferred embodiment, the material used for the containers is plastic, preferably polypropylene. The plastic may be tinted or colored with translucent or opaque color additives. In various aspects, the invention has a tab molded onto the side wall to allow easy identification and retrieval of the desired container. The tab may be labeled with a number or a letter which corresponds to a label table on the lid. In several embodiments, the current invention has an opening function which allows the user to pry apart two tabs with both thumbs. In one aspect of the invention, the inside center of the female side has a raised positioning ring which holds and centers the contents in the cavity formed by a male/female junction. By holding the contents in position, this ring prevents the contents from rubbing on the inside of the container 
   Various embodiments of the present invention provide stackable plastic containers which can be used for holding, organizing and/or securing optical disks. Optical disks, as used herein, shall mean digital and electronic data storage units, including, but not limited to CDs, DVDs, mini CDs, mini DVDs, floppy discs, computer, audio, video and digital camera discs, and the like. Methods of manufacturing and constructing these containers are also provided. Single non-stackable sealed plastic containers may also be made according to various aspects of the current invention. Some embodiments include ears designed to fit in different notebooks, three-ring binders, or day timers. 
   Several embodiments of the current invention are particularly advantageous because they offer light weight non-toxic containers which can be effectively be stacked upon one another and are capable of being latched or closed, thus creating a seal which keeps foreign material from entering the container. Thus, in a preferred embodiment, the current invention is particularly advantageous because it prevents dirt or foreign material from entering the container. A single non-stackable moisture/dirt sealed container can also be made using portions of the same design criteria, i.e. top female, bottom male sections. 
   In one aspect of the present invention, an apparatus for stackably storing items, including a first container, a surface included in the first container, the surface substantially planar, the surface having a first side and a second side, the surface having a shape suited to cover at least one item, a first member included in the first container, the first member raised from the first side of the surface, the first member having a first member perimeter, a second member included in the first container, the second member raised from the second side of the surface, the second member having a second member perimeter slightly larger than the first member perimeter, the second member suited to releaseably couple the first container to a first member of a substantially identical second container, wherein the first member forms a substantially complete perimeter around the first side of the surface, and, wherein the second member forms a substantially complete perimeter around the second side of the surface. 
   In one aspect of the invention, the first member forms a substantially complete ring around the first side of the surface. In another aspect of the invention, the second member forms a substantially complete ring around the second side of the surface. In another aspect of the invention, the second member includes a bead along the inside perimeter, the bead locking the first member of the second container to the second member of the first container and holding the first container and second container together. In another aspect of the invention, the bead is about 0.020 inches in radius. 
   Yet another aspect of the invention includes a tab extending from the surface of the first container, the tab suited to releaseably decouple the first container from the second container. In another aspect of the invention, includes a tang extending from the surface of the first container, the tang suited to prevent the tab of the first container from sliding past a tab of the second container. In another aspect of the invention, the first container is formed from plastic. In another aspect of the invention, the first container is formed from polypropylene. In another aspect of the invention, the first container is formed from clear plastic. In another aspect of the invention, the first container is formed from plastic opaque to visible light. In another aspect of the invention, the first container is formed from plastic opaque to ultraviolet light. In another aspect of the invention, the first container is formed from translucent plastic. In another aspect of the invention, the item stored is at least one of a compact disc or digital versatile disc or other optical disk. In another aspect of the invention, including a third container, the third container including a surface and first member substantially identical to the first container. In another aspect of the invention, a label attached to the second side of the third container. In another aspect of the invention, a tab extending from the surface of the first container, the tab suited to releaseably decouple the first container from the second container. In another aspect of the invention, a tang extending from the surface of the first container, the tang suited to prevent the tab of the first container from sliding past a tab of the second container. In another aspect of the invention, a fourth container, the fourth container including a surface and a second member substantially identical to the first container. In another aspect of the invention, a label attached to the first side of the fourth container. In another aspect of the invention, a tab extending from the surface of the first container, the tab suited to releaseably decouple the first container from the second container. In another aspect of the invention, a tang extending from the surface of the first container, the tang suited to prevent the tab of the first container from sliding past a tab of the second container. In another aspect of the invention, the height of the first member is slightly higher than the height of the item to be held by the container. In another aspect of the invention, the height of the first member is between about 0.010 inches and 0.125 inches. In another aspect of the invention, the surface of the first member is round. In another aspect of the invention, the width of the surface of the first container has an area slightly larger than the item to be held by the container. In another aspect of the invention, the width of the surface of the first container is between about 0.5 inches and 12 inches. In another aspect of the invention, the width of the surface of the first container is about 6 inches. In another aspect of the invention, the surface of the first member is rectangular. 
   Another aspect of the present invention includes a positioning ring, the positioning ring raised on the center of the second side of the surface of the first container, the positioning ring formed to hold the contents in the cavity formed by the second member of the first container and the first surface of the second container. In another aspect of the invention, a second positioning ring is included in the center of the second side of the second container. In another aspect of the invention, the positioning ring has a diameter ranging from about 0.5 inches to 0.6 inches. In another aspect of the invention, the positioning ring is raised from the second side of the surface of the first container to a height of about 0.010 inches to 0.300 inches. In another aspect of the invention, the substantially planar surface includes a slight curvature to protect the item from contact with the substantially planar surface. In another aspect of the invention, the substantially planar surface includes a slight curvature to protect the item from contact with the substantially planar surface. In another aspect of the invention, the first member is tapered such that a portion of the first member in contact with the substantially planar surface is thinner than a portion of the first member furthest from the planar surface. In another aspect of the invention, an outer edge of the first member forms an angle with the planar surface that is less than 90 degrees. In another aspect of the invention, the first member is substantially normal to the planar surface. In another aspect of the invention, the second member is substantially normal to the planar surface. 
   Another aspect of the present invention includes an apparatus for stackably storing items, comprising a first container, the container including a generally planar surface having a first side and a second side, a first member forming a generally complete perimeter generally normal to and around the first side of the generally planar surface, a second member forming a generally complete perimeter generally normal to and around the second side of the generally planar surface, the second member including a bead, and, a releasable coupling between the first container and a substantially identical second container, the coupling formed by the second member of the first container and the first member of the second container. Several embodiments of the invention further include a positioning ring, the positioning ring raised on the center of the second side of the surface of the first container, the positioning ring formed to hold the contents in the cavity formed by the second member of the first container and the first surface of the second container. 
   Another aspect of the invention includes an apparatus for stackably storing items, including a container means, the container means including a substantially planar surface with a first and second side, releaseable coupling means, the releaseable coupling means including a first member attached to the first side of the substantially planar surface and a second member attached to the second side of the substantially planar surface, and, an item fixing means, the item fixing means including a positioning ring to releaseably couple the item to the container. In another aspect of the invention, the first member forms a substantially complete perimeter around the substantially planar surface. In another aspect of the invention, the second member forms a substantially complete perimeter around the substantially planar surface. In another aspect of the invention, the second member includes bead means to seal the releasable coupling between a first container and a second container. 
   Yet another aspect of the invention includes an apparatus for storing items, where a first piece and a second piece where said first and second pieces are substantially planar and said first and second pieces each have a first and second surface, the first piece having at least one wall at or near its perimeter extending away from at least one of said surfaces, the second piece having at least one wall at or near its perimeter extending away from at least one of said surfaces, the at least one wall of the first piece and the at least one wall of the second piece are removeably joinable such that said first and second pieces and said walls form a container. In another aspect of the present invention the first and second pieces are attached by a hinge. 
   In another aspect of the present invention, the first piece forms a top of the container and the second piece forms a bottom of the container and the top piece includes at least one positioning member for orienting an item to be contained in the container. In another aspect of the present invention the bottom contains at least one positioning member for orienting an item to be contained in the container. In another aspect of the present invention, the bottom contains at least one positioning member for orienting an item to be contained in the container. In another aspect of the present invention, the container is substantially round, said first piece forms a bottom and said second piece forms a top, said bottom piece having a center positioning member and a perimeter positioning member. In another aspect of the present invention, the top piece has a center positioning member. In another aspect of the present invention, the top piece has a perimeter positioning member. In another aspect of the present invention, the top piece has a perimeter positioning member. 
   Another aspect of the present invention includes an apparatus for storing items, including a substantially planar and substantially round first piece with a diameter of approximately between about 3.0 inches to about 5.5 inches, a first wall extending laterally from said first piece a distance of approximately between about 0.06 inches to 0.12 inches, a second piece that is substantially planar and substantially round with a diameter of approximately between 3.0 inches to about 5.5 inches, a second wall extending laterally from said second piece a distance of approximately about 0.06 inches to about 0.12 inches, with a positioning ring in the center of each of the first and second piece, where said positioning rings are raised from a surface of each of said pieces approximately between about 0.01 inches to 0.12 inches, said positioning rings having diameters of approximately about 0.20 inch to about 0.62 inches, where said first piece has a stabilizing ring raised from the surface with a diameter approximately between about 2.5 inches and about 5 inches. In another aspect of the present invention the second piece has a stabilizing ring on the surface with a diameter approximately between about 2.5 inches and about 5 inches. In another aspect of the present invention, the container is designed to hold an optical disk and to prevent dust, dirt, moisture, and other debris from reaching said disk. 
   In other embodiments, an apparatus is disclosed for individually storing for easy retrieval a plurality of items in respective individual indexed nestable containers which are each substantially sealed against intrusion of foreign material into the container, the containers adapted to form a generally cylindrical stack which resists coming apart unless and until entry of one or more containers is desired, the apparatus having a plurality of mating container members, each of the members having a substantially planar surface having a first side and a second side, a first substantially circular peripheral enclosure upstanding from the first side, a second substantially circular peripheral enclosure upstanding from the second side, the inner perimeter of the second peripheral enclosure being sufficiently larger than the outer perimeter of the first peripheral enclosure so that the second peripheral enclosure fits over and grips the first peripheral enclosure of another one of the mating container members to abut against the second peripheral enclosure of the mating container member, whereby second substantially circular peripheral enclosures and first substantially circular peripheral enclosures of adjacent container members are adapted to respectively combine to form a stack of plural nestable containers substantially sealed against intrusion of foreign matter, and outwardly extending indexing members on the mating container members adapted to engage the indexing member of an adjacent mating container members to enable indexing of multiple stacked container members. 
   Also disclosed is an apparatus for individually storing for easy retrieval a plurality of items in respective individual indexed nestable containers which are each substantially sealed against intrusion of foreign material into the container, the containers adapted to form a stack which resists coming apart unless and until entry of one or more containers is desired, the apparatus having a plurality of mating container members, each of the members having a substantially planar surface having a first side and a second side, a first substantially circular peripheral enclosure upstanding from the first side, a second substantially circular peripheral enclosure upstanding from the second side, the inner perimeter of the second peripheral enclosure being sufficiently larger than the outer perimeter of the first peripheral enclosure so that the second peripheral enclosure fits over and grips the first peripheral enclosure of another one of the mating container members to abut against the second peripheral enclosure of the mating container member, whereby second substantially circular peripheral enclosures and first substantially circular peripheral enclosures of adjacent container members are adapted to respectively combine to form a stack of plural nestable containers substantially sealed against intrusion of foreign matter, and outwardly extending indexing members on the mating container members adapted to engage the indexing member of an adjacent mating container members to enable indexing of multiple stacked container members. 
   Also disclosed is an apparatus for individually storing for easy retrieval a plurality of items in respective individual nestable containers which are each substantially sealed against intrusion of foreign material into the container, the containers adapted to form a stack which resists coming apart unless and until entry of one or more containers is desired, the apparatus having a plurality of mating container members, each of the members having a substantially planar surface having a first side and a second side, a first substantially circular peripheral enclosure upstanding from the first side, a second substantially circular peripheral enclosure upstanding from the second side, the inner perimeter of the second peripheral enclosure being sufficiently larger than the outer perimeter of the first peripheral enclosure so that the second peripheral enclosure fits over and grips the first peripheral enclosure of another one of the mating container members, whereby second substantially circular peripheral enclosures and first substantially circular peripheral enclosures of adjacent container members are adapted to respectively combine to form a stack of plural nestable containers substantially sealed against intrusion of foreign matter. 
   Also disclosed is an apparatus for individually storing for easy retrieval a plurality of items in respective individual nestable containers which are each substantially sealed against intrusion of foreign material into the container, the containers adapted to form a stack which resists coming apart unless and until entry of one or more containers is desired, the apparatus having a plurality of mating container members, each of the members having a substantially planar surface having a first side and a second side, a first peripheral enclosure upstanding from the first side, a second peripheral enclosure upstanding from the second side, the inner perimeter of the second peripheral enclosure being sufficiently larger than the outer perimeter of the first peripheral enclosure so that the second peripheral enclosure fits over and grips the first peripheral enclosure of another one of the mating container members, whereby second peripheral enclosures and first peripheral enclosures of adjacent container members are adapted to respectively combine to form a stack of plural nestable containers substantially sealed against intrusion of foreign matter. 
   Also disclosed is an apparatus for individually storing for easy retrieval a plurality of items in respective individual indexed nestable containers which are each substantially sealed against intrusion of foreign material into the container, the containers adapted to form a stack which resists coming apart unless and until entry of one or more containers is desired, the apparatus having a plurality of mating container members, each of the members having a surface having a first side and a second side, a first substantially circular peripheral enclosure upstanding from the first side, a second substantially circular peripheral enclosure upstanding from the second side, the inner perimeter of the second peripheral enclosure being sufficiently larger than the outer perimeter of the first peripheral enclosure so that the second peripheral enclosure fits over and grips the first peripheral enclosure of another one of the mating container members, whereby second substantially circular peripheral enclosures and first substantially circular peripheral enclosures of adjacent container members are adapted to respectively combine to form a stack of plural nestable containers substantially sealed against intrusion of foreign matter; outwardly extending indexing members on the mating container members adapted to engage the indexing member of an adjacent mating container members to enable indexing of multiple stacked container members; a positioning member on at least the first or second side to hold in position an optical disk within the formed nestable containers. 
   Also disclosed is an apparatus for individually storing for easy retrieval a plurality of items in respective individual indexed nestable containers, the containers adapted to form a stack which resists coming apart unless and until entry of one or more containers is desired, the apparatus having a plurality of mating container members, each of the members having a surface having a first side and a second side, a first substantially circular peripheral enclosure upstanding from the first side, a second substantially circular peripheral enclosure upstanding from the second side, the inner perimeter of the second peripheral enclosure being sufficiently larger than the outer perimeter of the first peripheral enclosure so that the second peripheral enclosure fits over and grips the first peripheral enclosure of another one of the mating container members, whereby second substantially circular peripheral enclosures and first substantially circular peripheral enclosures of adjacent container members are adapted to respectively combine to form a stack of plural nestable, outwardly extending indexing members on the mating container members adapted to engage the indexing member of an adjacent mating container members to enable indexing of multiple stacked container members; a positioning member on at least the first or second side to hold in position an optical disk within the nestable containers, formed by adjacent mating container members. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIGS. 1A–1D  depicts one embodiment of a cross section of a container stack, including a top lid, two center containers, and a bottom container. 
       FIGS. 1E–1H  depict cross-section of another embodiment of a container stack. 
       FIG. 2  shows one embodiment of the top lid of the container stack, where typically only one top lid is used per stack. 
       FIG. 3  depicts one embodiment of a center container, where the center container forms the container section on top and the lid of the next container on the bottom. 
       FIG. 4  illustrates one embodiment of the bottom container, which forms the base of the stack of containers. 
       FIG. 5  is a top view of a top container. 
       FIG. 6  is a top view of one embodiment of a center container. 
       FIG. 7  depicts one embodiment of the bottom section looking into the container cavity. 
       FIG. 8  illustrates one embodiment of the center container first member, second member, first bead and second bead, which holds items stored therein. 
       FIG. 9  shows one embodiment of a container stack, including a top lid and a bottom container. 
       FIG. 10  shows one embodiment of a container stack, including a labeled top lid, a center container, and a bottom container. 
       FIG. 11  illustrates one embodiment of a container stack where center containers are aligned with their tabs in a spiral fashion. 
       FIG. 12  shows a top view of one embodiment of a center container. 
       FIG. 13  shows a top view of a single disc container with featuring hinged top and bottom pieces. 
       FIG. 14  shows a top view of another embodiment of a container including a hinge and ears. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIG. 1  depicts one embodiment of a cross section of a container stack, including a top lid  100 , two center containers  110 , and a bottom container  120 . The center containers  110  each include a generally planar surface  130 , where the planar surface is substantially flat and typically of a size slightly larger than the shape of the items to be held in the container stack. Thus, if the container stack is to hold compact disks (CDs), the planar surface will have a width of at least the diameter of a CD (approximately 4.75 inches) and preferably will be a circular disc with a diameter slightly greater than the CD diameter or a rectangle with sides of the same dimension (See  FIGS. 1E–1H , wherein similar components to those in  FIGS. 1A–1D  have the same reference numeral, except that a “′” has been added to the reference numerals). The generally planar surface  130  typically has a first side  134  and a second side  132 . The first side  134  is also generally flat, and contains a first member  140  which is generally normal to the first side. Advantageously, the first member  140  typically follows at or near the perimeter of the generally planar surface  130 , and typically has a height slightly greater than the height of the items to be held in the container. Thus, if the container stack is to hold CDs, a height of, for example, about 0.100 inches can be advantageously used. Similarly, the second side  132  is generally flat, and contains a second member  170  which is normal to the second side. The second member  170  typically follows at or near the perimeter of the generally planar surface  130 , but with a diameter or perimeter advantageously slightly greater than the diameter or perimeter of the first member  140 . It is noted that the second member  170  may alternatively have a diameter or perimeter slightly smaller than the first member  140 . Also, the second member  170  and/or first member  140  may include a double wall design where two parts of one or both members fits snugly with the corresponding part(s) of the other member. 
   Preferably, in one embodiment, the first member  140  forms a continuous ring near the perimeter of the first side  134  of the planar surface  130 , where the shape of the ring varies based on the shape of the planar surface  130  and items to be stored therein, and the second member  170  similarly forms a continuous ring near the perimeter of the second side  132  of the planar surface  130 . Advantageously, for example, the second member  170  creates a ring slightly larger than the ring created by the first member  140 , such that a first container  110  and a second container  110  can be releasably stacked by coupling of the first member  140  of the first container to the second member  170  of the second container. One skilled in the art will understand that other shapes in addition to rings may be used in accordance with various embodiments of the current invention, and the shape of the first member  140  and second member  170  will vary based on the shape of the planar surface  130  and items to be stored in the container  110 . 
   In several of the preferred embodiments, the releasable attachment of multiple containers is further aided by the addition of a first bead  150  placed along the outer edge of the first member  140 . Some embodiments such as those depicted in  FIG. 1  include a second bead  180  placed along the outer edge of the second member  170 . In other preferred embodiments, only one bead  180  is found on the second member  170 . Embodiments with no beads are also envisioned. In some embodiments, a bead  150  on the first member  140  may match an indented ridge on the second member. In many embodiments, one of either the first or second member will include a bead  150  with the other member having an orientation in which it is angled with respect to the planar surface  130 , as shown in  FIG. 10 .  FIG. 12  shows another preferred embodiment in which the second member  170  has an angled surface that corresponds to an internally angled first member  140 . 
   While it is not necessary, the first bead  150  and second bead  180  preferably run continuously along the surface of the first member  140  and second member  170  respectively. Upon coupling of the first member  140  of a first container to the second member  170  a seal is created against the external environment which advantageously protects the items stored therein from dirt, pollutants, liquids, and the like. In other embodiments, an o-ring may be used to aid in the sealing of the container. 
   In a one embodiment of the present invention, a positioning ring  160  is included in the center of the second side  132  of the generally planar surface  130  of the container. The raised positioning ring  160  typically has a diameter ranging from about 0.200 inches to 0.600 inches and a height ranging from about 0.010 inches to 0.300 inches. This positioning ring  160  holds and centers the item stored in the container, such as for example, a CD, in the cavity formed by a junction of the first member  140  of a first container and a second member  170  of a second container. The inside hole of an optical disk, like a CD or DVD, or any similar item to be stored, has an interference fit with an outside drafted, radiused, or tapered diameter of the positioning ring  160 . The contents, including, but not limited to optical disks such as CDs, CD-Rs, CD-RWs, DVDs, Laser Disks, mini CDs, and mini DVDs, can be held away from the first side  134  by the draft angle or taper on the outside diameter of the ring  160 . By holding the contents in position, this ring  160  can help prevent the contents from rubbing on the inside surfaces of the container. While it is not a necessary feature of the disclosed invention, in some embodiments, an item to be stored is in contact with only contact positioning ring  160 .  FIG. 12  shows another feature of some embodiments in which a positioning ring  160  is included on both sides of a center container  110 . In some of the embodiments exhibiting this feature an optical disk or other item touches only the top and bottom positioning rings  160 . Some of the embodiments depicted in  FIG. 12  prevent movement of an optical disk or other item as it is held in a closed container. Additionally,  FIG. 12  shows an stabilizing rib  162  that helps secure the outer edges of an optical disc. Some embodiments include more than one stabilizing rib  162  and some embodiments include stabilizing ribs on the first sides  134  and the second sides  132 . 
   In addition to, or instead of, the positioning ring  160  on the first side  134 , a raised positioning ring  160  can be placed on the second side  132  as shown in  FIG. 12 . Other embodiments have a positioning ring  160  on both sides. 
   In another preferred embodiment, the combined height of any combination of positioning rings  160  does not exceed the height of the cavity formed by a junction between two center containers  110 , between a center container  110  and a top lid  100 , and/or between a center container  110  and a bottom container  120 . 
     FIGS. 2 and 3  depicts other embodiments in which the containers include a tab  220  and tang  230 . The tab  220  typically extends from the generally planar surface  130  and aides in prying open a first container and a second container to retrieve the item contained therein. For some embodiments, on one edge of the tab  220  advantageously is included a tang  230 . The tang  230  permits the tab  220  for each center container  110  as well as the top container  100  to easily be aligned to permit simple indexing of the tabs  220  for various items stored in the container(s). Alignment is achieved by rotation of each level of the stacked containers such that the tang  230  of one level contacts the tab  220  of an adjacent level, thereby limiting the rotation of the tang  230 . In several embodiments, this alignment affords a spiral arrangement as shown in  FIG. 11  where all or some of the tabs  220  can be seen from an overhead view or an angled view. Advantageously, in one embodiment, depicted in  FIG. 4 , the bottom lid  120  also includes a bottom tab  190 . The bottom tab  190  in one embodiment is an ordinary tab  220 , but in a preferred embodiment is an extension of the generally planar surface  130  of the bottom lid  120  that extends around the entire perimeter of the bottom lid  120 . In other embodiments, the bottom tab  190  may be a button or a bump or a tang or a similar feature that limits the rotation of a tang on an adjacent center container  110 . 
   Another feature of many embodiments includes a tang  230  on the tab  220  that allows for the tabs  220  to be offset rotationally at each level. This creates a spiral column of tabs  220  as shown in  FIG. 11 . Labels including data or indicia can be included on the tabs  220  and can be quickly and easily referenced with the tabs  220  spiraled. In one embodiment shown in  FIG. 4 , the bottom male container has a tab  220  that runs around the entire outside diameter except for an area of about 0.200 inches. This gap  240  is where the tang  230  from an adjacent center container  110  is positioned for proper closing. Each tang  230  hangs below the bottom of the center container  110  to which it is attached by about 0.070 inches and stops the tab  220  of the container below from overlapping the tab  220  connected to the tang  230 . This tang/tab combination makes a mechanical stop. In some embodiments, each tang  230  has a gap ranging from about 0.040 inches to 0.050 inches, so that the bottom of the tang  230  does not come into contact with adjacent container. 
   In some preferred embodiments of the current invention, tabs  220  and tangs  230  are used for indexing. Each container has a marking on a tab  220 . In some embodiments, the top lid  100  has a raised rib  260  around the outer diameter as seen in  FIG. 2 . The rib  260  is on the flat surface  130  and ranges from about 0.010 inches to 0.050 inches in height. This allows for a label or other indicia on the top lid  100  and protects such a label from scratches or smears that may occur if the flat surface  130  were allowed to touch other surfaces, such as a tabletop, as would be the case without the rib. The label can include any number of indicia that correspond to the tabs  220  so as to indicate the contents associated with each tab  220 . In some embodiments, a user can change the indicia as the contents are changed. The tangs  230  located on the outside diameter wall can have an attached tab  220 , which also will have a flat surface for some type of indicia. The tab  220  of the invention can be larger if a larger label is needed for more information. For some embodiments, the tab size for the invention is about 2 inches in length, but preferably about 1.2 inches. 
     FIG. 8  illustrates one embodiment of the center container  110  first member  140 , second member  170 , first bead  150  and second bead  180 , which holds items stored therein. In some preferred embodiments, the current invention is especially advantageous because it seals out dirt, moisture and the outside environment. It is foreseen that the size of the first bead  150  and second bead  180  and other aspects of the first member  140  and second member  170  may be adjusted to make the seal between a first container and a second container “tight” in order to prevent inadvertent opening, or “loose” to allow ease of opening. 
   In several embodiments, the current invention has an opening function which allows the user to pry apart two tabs  220  with both thumbs. The smallest hands to the largest hands are capable of doing this. In various aspects, this invention allows easy retrieval of the desired container with the use of a tab  220  molded on each center container  110 . 
   In several embodiments of the current invention, the container is used for holding, organizing or securing optical discs such as CDs, DVDs, mini CDs, mini DVDs, and floppy discs. One skilled in the art will understand that the containers of the present invention may be used for any object that can fit into the cavity formed by a male/female junction of a first member  140  and a second member  170 . 
     FIG. 2  shows one embodiment of the top lid of the container stack, where typically only one top lid is used per stack.  FIG. 5  illustrates one embodiment of the top container section looking down into the inside. 
   Returning to  FIG. 1 , the bottom lid  120  typically includes a generally planar surface  130 , and a bottom surface  210 . The second side  134  of the bottom lid  120  includes a second member  170 , typically including a second bead  180 . The bottom surface  210  typically is left substantially flat for inclusion of secondary features such as labels, advertisements, or attachments. The use of a flat outer surface for the bottom lid  120  and top lid  100  also provide a simple placement position for the container from which the container advantageously will not roll or fall.  FIG. 4  illustrates one embodiment of the bottom container, which forms the base of the stack of containers.  FIG. 7  depicts one embodiment of the bottom section looking into the container cavity. In this embodiment, a bottom tab  190  extends around most of the perimeter of the bottom container  120 . An optional tab  220  and tang  230  are shown as well, although either form of tab may be used with or with out the other. Advantageously, a gap  240  in the bottom tab may be included to catch the tang  230  from center containers  110  or top containers  100  placed directly above the bottom container  120 . 
   In one aspect of the invention, the container is made from clear plastic to allow the user to view the contents in the cavity. In other embodiments, the plastic is tinted or colored with translucent or opaque color additives. In a preferred embodiment, an opaque container which filters potentially damaging UV light is used. Accordingly, the user is able to take the discs into the direct sunlight. 
   In some embodiments, the container is square-shaped or rectangular-shaped. (See  FIGS. 1E–1H ). In a preferred embodiment, the container is made of plastic that is softer than the polycarbonate plastic used in optical disks, thus preventing or minimizing any damage to the optical disk itself. In some preferred embodiments, surprising new advantages were found using polypropylene. Many plastics have been found to have a degrading effect on optical disks over time. Polypropylene was found to be non-toxic to optical disks. 
     FIG. 10  shows additional features of some embodiments of a container stack, including a top lid  100 , a center container  110 , and a bottom container  120 . Some features of the embodiments represented in  FIG. 10  include a container that, when sold as a commercial distribution container, includes two optical disks  250 , or alternatively one optical disk  250  and one set of informational material such as a CD booklet (not shown). Advantageously, a label  260  is added to the top lid  100  and optionally the bottom lid  120  as well. Upon purchase of the commercial distribution container, the consumer can combine the top lid  100 , center container(s)  110 , and/or bottom container  120  with the consumer&#39;s other containers purchased in accordance with the present invention, to create a variable size 
   Several embodiments of the present invention hold only a single optical disk or other item and may or may not be stackable. Many of these embodiments are depicted in  FIG. 13 .  FIG. 13  shows one such embodiment where the top lid  305  is connected to the bottom lid  307  by a hinge  300 . In other single container embodiments, the top lid  305  and bottom lid  307  are separable. Additional single disk container embodiments include ears  310  that allow the container to be snapped or hooked into a carrying case. For example, one feature of  FIG. 13  is the ears  310  designed to be hooked into a two or three-ring binder or a day-timer. The ears  310  depicted in  FIG. 13  may also be used in stackable, multi-item containers. 
   Another feature of many embodiments is a guard ring  330  as shown in  FIGS. 12 and 13 . The guard ring  330  extends laterally near or beyond the opening tab  340  and provides protection from accidental opening such as may result from dropping the container or inadvertently brushing the opening tab  340  against another surface. 
   The guard ring  330  also serves a function when the containers are sorted by some types of machines such as sorting devices and roller devices. For example, many post offices use rollers in various ways to process, sort, or maneuver mail and some roller devices have trouble climbing over objects that are too thick or too tall. In such situations, the guard ring  330  functions as a ramp and is helpful because it allows the roller to gradually roll over the total thickness or height by first rolling on to the relatively thin guard ring  330 . 
   and the guard ring  330  acts as a ramp allowing the roller to first climb the height of the guard ring and then climb over the highest edge of the container. 
   While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art the various changes in form and details may be made therein without departing from the scope of the invention.