PATENT ABSTRACT
A collapsible shipping container is provided with channels formed into the interior surface of the top frame of the collapsible shipping container to accept support rods and interior dunnage which depend from the support rods. The interior dunnage preferably is fabricated of flexible or foldable material which may be gathered and positioned such that the collapsible shipping container may be collapsed while the dunnage remains at all times within and associated with the collapsible shipping container. The dunnage may be in the form of hanging pouches supported by support rods and may further include hanging curtains supported by support rods orthogonally intersecting the pouch support rods. Whenever the hanging curtains are utilized, the hanging pouches are made of material which permits and forms a gap between adjacent pouches to accommodate the curtains. Should the items being shipped need protection from electrostatic discharge, electrically conducting pliable material may be used to form the pouches and/or the curtains supported by the support rods.

PATENT DESCRIPTION
FIELD OF THE INVENTION 
     This invention relates to collapsible shipping containers and, more specifically, to a collapsible shipping container designed or adapted to retain collapsible interior dunnage and partition systems within the collapsed shipping container itself for a return shipment or storage. 
     BACKGROUND OF THE INVENTION 
     The use of reusable shipping containers has become a practice in industry for several reasons. First, reusable containers are sturdy and provide a high level of protection to shipped items compared to the customary, corrugated fiberboard containers. Second, the lifetime cost per use is generally less for a reusable shipping container. Third, environmental considerations weigh in favor of reusable containers which require less frequent replacement and offer various recycling options. 
     Return shipments of collapsible reusable shipping containers to the originating shipper are more economical and efficient than non-collapsible units. Collapsing the shipping container to a fraction of its erected size allows a more dense load to be shipped, as it may cost no more to ship three to four times the number of collapsed containers than to ship a lesser number in an erected condition. This is particularly true if the freight charge is calculated, not by weight, but either on a truck load basis or on a set volume of freight. 
     For those items requiring individual packaging during shipment and handling, collapsible shipping containers as previously designed have not been an advantageous choice. A major problem with current collapsible shipping containers is the separate interior dunnage itself, dividers and separators. This has been true whether shipment is made to assembly operations, between locations within a single facility, or over distances as from a supplier to a manufacturer. 
     One handling problem with conventional dunnage is that the dunnage or internal packaging must be removed from a shipping container and disassembled or collapsed separately, or it becomes an obstacle and interferes with the collapsing of the collapsible shipping container. Once removed, the conventional dunnage is no longer a part of the container assembly, requires separate handling, shipment and accounting and, further, is subject to loss or damage. Thus, the advantages of the collapsible, reusable shipping container for shipments of unpackaged items diminish with the handling requirements for the currently designed separate dunnage. Moreover, once removed and shipped as a separate item, dunnage consumes space in the return shipment and reduces return shipment efficiencies. 
     Dunnage in the form of corrugated fiberboard orthogonally interdigitated dividers, left assembled and collapsed, typically collapse to a dimension larger than the footprint of its collapsible shipping container and create additional handling problems. Completely disassembled, these dividers compound the problem of return shipment and require disassembly and re-assembly labor. In the instance of conductive or conductively coated dunnage for shipment of electronic circuit boards and circuits having electrostatic discharge sensitive components, separate handling of the collapsed interlocked dunnage tends to degrade those properties which are responsible for protection against electrostatic discharge damage to electronic circuit boards. 
     These and other shortcomings can prevent efficient and cost effective use of collapsible reusable shipping containers for shipping fragile items requiring separation and protection from incidental contact during shipping and handling. 
     OBJECTS OF THE INVENTION 
     It is an object of the invention to protect items shipped in a collapsible shipping container by means of dunnage which itself is enclosed within the collapsible shipping container and is erect for usage or in a collapsed state. 
     It is another object of the invention to provide collapsible interior dunnage which remains within its collapsible shipping container during container usage or return shipment. 
     It is a further object of the invention to render a collapsible shipping container usable for shipping fragile items which ordinarily require protective packaging without individually packaging the items. 
     It is still another object of the invention to improve the usability of collapsible shipping containers. 
     It is a still further object of the invention to improve the efficiency of use of collapsible shipping containers. 
     It is an additional object of the invention to reduce the shipping expense of collapsible shipping containers and associated dunnage as well as any associated labor savings. 
     SUMMARY OF THE INVENTION 
     In order to incorporate dividers or dunnage into a collapsible shipping container in a manner to insure at all times the association of the dunnage with its container yet not to impede the collapse of the container for return shipment, a collapsible shipping container is provided with at least a pair of channels in the top frame attached to the top edges of the four side walls of the container. These channels, disposed in the top frame sides that are opposed to each other, support and retain support rods with flanges on their ends. 
     Rods spanning the opposed top frame side channels, and the collapsible shipping container interior together support a preferably flexible material forming a hanging pouch or pouches for receiving individual items to be shipped and for protecting each item from contact with another item. Preventing contact between items protects them from damage during shipping and handling. 
     The hanging pouch may extend substantially across the container interior to accept a single item or may be divided longitudinally and arranged with laterally extending dividers or curtains suspended from rods supported by a pair of opposing channels disposed in orthogonal segments of the frame. This arrangement creates a plurality of small pouches for supporting and isolating smaller items. 
     Whenever the curtains are used, the curtain supporting rods should be preferably disposed below the rods supporting the material forming the hanging pouches. 
     The dunnage may be replaced as worn or damaged with use and can be changed to accommodate changes in items shipped, thus making the shipping container more beneficial. 
     These dunnage arrangements lend themselves to easy collapse and erection plus remain confined in and directly associated with the container during all phases of use and shipment in order that the dunnage is not lost or separated from its container which would significantly reduce their utility. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a collapsible shipping container in an erected, closed state. 
     FIG. 2 illustrates the collapsible shipping container of FIG. 1 in an open state with dunnage illustrated suspended within the interior of this container. 
     FIG. 3 illustrates the interior dunnage extended to show construction details. 
     FIG. 4 is a partially exploded detailed illustration of the interior of the side walls of the shipping container and dunnage showing channels which support the dunnage, as well as three embodiments for retaining the dunnage support rods in the channels. 
     FIG. 5 is an illustration of dunnage suitable for use in the collapsible shipping container of FIGS. 1,  2  and  4  wherein the collapsible shipping container is to be subdivided into a matrix of pouches. 
     FIG. 6 is an illustration of a dunnage curtain which can be installed in the collapsible shipping container of FIGS. 1,  2  and  4  along with the dunnage illustrated in FIG. 5, thereby forming a matrix of individual pouches. 
     FIG. 7 illustrates the arrangement of the dunnage of FIGS. 5 and 6 creating the individual pouches. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     OF THE BEST MODE OF THE INVENTION AS CONTEMPLATED BY THE INVENTOR 
     Initially, reference is made to FIG.  1 . The collapsible shipping container  10  illustrated is typically assembled from injection molded plastic parts. Bottom member  12  is molded to include a partial hinge  28  on two of its four edge portions  16  in an opposing arrangement. Forming hinge  29  is partial hinge  28  and partial hinge  30  which is molded as a part of side panel  24  of collapsible shipping container  10 . Pivotally attached at hinge  27  to side panel  24  is a similar side panel  26 . Side panel  26  is further hinged at hinge  34  to top frame  32 . Hinges  29 ,  27  and  34  thus connect side panel segments  24 ,  26  to bottom  12  and to top frame  32  forming a collapsible wall. The same arrangement is found on the opposing wall (not visible) of collapsible shipping container  10 . 
     Covers  36  are pivotally attached to the top frame  32  at edge hinges  38 , thereby permitting the covers  36  to be laid open. 
     End panel  22  of collapsible shipping container  10  is hinged to top frame  32  and functions as a rigid compression member once collapsible shipping container  10  is fully erected. A second end panel  22  is similarly found at the opposite end of collapsible shipping container  10 . The end panels  22  are rigid and strong enough in an erected state to support not only the top frame  32  and covers  36  but also other similar containers and their contents stacked thereon. 
     End panels  22  may be pivotally displaced inwardly and upwardly for collapse if shipping container  10  is empty. Once panels  22  have been displaced around their hinge  18  into a position generally horizontal and parallel to bottom member  12 , side panels  24  and  26  may be folded and displaced inwardly toward the interior chamber of shipping container  10  around hinges  28  and  34 , respectively. Hinge  27  provides necessary pivotal movement between side panels  24 ,  26  and top frame  32  and thus will be lowered toward bottom member  12 . 
     The features of collapsible shipping container  10  described thus far are conventional in that they may be found in some form in collapsible shipping containers of various manufacturers. A container similar to the one described thus far may be acquired from Monoflo International Inc. of Winchester, Va. As one of skill in the art will appreciate, collapsible containers are very efficient for shipping and return for reuse. Large quantities of this type of collapsible shipping container are utilized to efficiently reduce return shipment costs which are significant inasmuch as the container may be reduced to approximately one-fourth its erected height for storage or return shipment. 
     Collapsible containers, such as described above, are particularly usefull and beneficial for shipping either bulk types of items or items which are individually packaged and not subject to damage by contact with other packaged goods. However, should the container  10  be used to ship unpackaged items, interior dunnage may be required to separate and protect the items, such as electronic circuit boards, from contact between themselves as well as to prevent buildup of damaging electrostatic charges. 
     It is important that items such as electronic circuit boards or electronic components be shipped from their point of manufacture to a point of assembly without individual packaging in order to eliminate the cost of such packaging and associated labor necessary to package and unpack the items. Individual protective packaging of the items shipped is not only expensive, individual package costs and productivity drops combine for an overall higher cost for the manufactured device. 
     Frequent replacement of conventional dunnage such as matrix corrugated fiberboard dividers can be expensive and necessitated by ordinary shipment, handling or damage. Further, matrix corrugated fiberboard dividers do not collapse into a small enough volume to fit within and remain associated with its advantageously collapsed container. 
     Referring now to FIG. 2, covers  36  are illustrated in an open position and expose to view the interior of the collapsible container  10 . Container  10  is illustrated in its fully erected state with only a single pouch dunnage divider  60  detailed for clarity. 
     In order to support dunnage divider  60 , top frame  32  is fabricated with a slot  50 . The preferred configuration of slot  50  is a “T” shape with the crossbar of the “T” oriented vertically within the top frame member  32 . For flexibility in shipping dissimilar items, the “T” shaped slots  50  may be formed into all four sides of top frame  32  and the container reconfigured with only a change in the dunnage. 
     Similarly, slot  50  may be formed into opposing segments  33 . The vertical bar of the “T” shaped slot  50  opens through interior surfaces  52  of at least two opposing side segments  33  of top frame  32 . Due to orientation, slot  50  is shown only in one of each pair of the opposing segments. Slot  50  may be provided prior to assembly either in the molding process or cut with a router type bit in either a router or a milling machine during manufacture. Assuming adequate economies of scale, the molding operation may prove to be superior from a cost standpoint. 
     When slots  50  are formed into all four sides of top frame  32 , slots  50  in the end segment  31  of top frame  32  are disposed at a different elevation than the slots  50  in side segments  33  of top frame  32 . As an additional advantage, this arrangement permits use of intersecting sets of dunnage as will be described below. 
     Erection of container  10  is accomplished by lifting top frame  32  away from bottom member  12  and returning end panels  22  and side panels  24 ,  26  to their vertical orientation. Latch or catch surfaces (not shown) may be used to maintain all side and end panels  24 ,  26 ,  22  in their erected orientation for handling and use. End panels  22  will serve as compression members and thus support top frame  32  in its erected position. The support of top frame  32  by end panels  22  will prevent the collapse of top frame  32  downwardly toward the bottom member  12  of the collapsible shipping container  10 . 
     Referring now to FIG. 3, dunnage in the form of dividers or separators  60 , as discussed for use in this invention, may be fabricated of flexible material and, as needed, may be electrostatically protective. Dividers  60  advantageously can be formed by creating tubes  62  of the divider material, preferably by folding over the material at selected intervals and joining the juxtaposed surfaces at contact zone  64  by any suitable process. Possible processes for joining include gluing, heat sealing, sewing or stitching, and ultrasonically bonding. The tubes  62 , so formed, will each accommodate a suspension rod  70 . 
     Permanent flanges  72  are fabricated on both ends of suspension rods  70 . The flange  72  may be formed on the suspension rod  70  by an appropriate forming process or may be attached by welding, brazing, or soldering onto the suspension rod  70  an appropriate sized washer or disk, thereby creating a flange  72 . 
     An alternative to the circular flange  72  is a bar attached across the end of rod  70  forming a “T” shape. The flexible material then must be attached to rod  70  to orient the “T” crossbar perpendicular to slot  50  once the flexible material hangs within erected collapsible container  10 . This embodiment provides an easy way to change or replace dunnage  60  as the need arises. 
     In order that the support rod  70  be freely movable along the length or width of the collapsible shipping container  10 , the support rod  70  must be smaller than the width of the stem of the “T” shaped slots  50  and the flanges  72  similarly somewhat smaller than the crossbar of the “T” shaped slot  50 . This insures that the flanges  72  and support rods  70  have clearance to be freely movable. 
     As may be observed in FIG. 4, top frame  32  is fabricated with an access channel  80  formed to intersect with and expose one end of the “T” shaped channel  50 . Flanges  72  and support rods  70  of dunnage dividers  60  then may be engaged within channel  50  and slid along channel  50 . Additional flanges  72  and rods  70  may be added to provide a plurality of segments  74  arranged suspended from support rods  70 . A block  82  may be inserted into channel  80  and fastened therein by a screw or other retainer (not shown) in order to prevent any disengagement of flanges  72  and support rods  70  from channels  50 . 
     As many segments  74  of the dividers  60  may be ganged or made in a single dunnage assembly as desired, and typically the number of segments will be determined by the bulk of the objects or items being packaged therein for shipment. Although this will tend to customize a collapsible shipping container  10  to use for a particular part or time, simply changing the dunnage dividers  60  will re-adapt the container  10  to use for shipment of a different item. Much of the efficiency of use of such containers  10  is due to the frequent usage of a particular combination of container  10  and dividers  60  as handled between a paired shipper and receiver. 
     Slots  50  in top frame  32  are illustrated at different elevations in FIG. 4 as discussed previously. While having the slots  50  at different levels in top frame segments  31 ,  33  is not required, flexibility in dunnage adaptation is provided without additional costs of manufacture or retrofit. 
     Flanges  72  and support rods  70  are engaged into opposed channels or slots  50  and are slidably movable along slots  50  for ease in loading and unloading and adapting the pouch  76  to the items being shipped. The items being shipped then may be inserted into an expanded segment  74  of suspended segments  74  of dividers  60 . 
     FIG. 4 further illustrates additional embodiments of the channel  86  and an element for accessing slot  50  and blocking removal of rods  70  and flanges  72  from slots  50 . A further “T” shaped slot  86  may be cut or formed into top frame  32  orthogonally intersecting slot  50 . Slot  86  permits insertion of rods  70  and flanges  72  into slot  50 . The egress of rods  70  and flanges  72  from slot  50  is denied by “T” shaped plug  88  which fits within “T” shaped slot  86 . 
     Plug  88  may be frictionally retained or may be retained in position by plate  90  which is disposable over slot  86  and further retained by fasteners such as screws  92  engaged through holes  94  of plate  90  and with screw holes  96  in top frame  32 . 
     Where it is desirable to transport relatively large, generally flat items such as printed circuit boards, either populated or unpopulated, the orientation of the dividers  74  or dunnage  100  may be selected to extend across or lengthwise of container  10  as desired and permit insertion of one printed circuit card into each segment  74  or pouch  76  which closely fits the items shipped. 
     However, there are times when smaller sized items are to be shipped and if more than one such item is loaded into a single pouch  76  of dunnage  100 , damage may occur to either or both items. In this circumstance the items must be protected from shifting into positions whereby contact between items can occur with damage sustained by one or both of the items making contact. 
     This protection may be accomplished by using a second set of dividers, such as seen in FIG. 6, where the flexible material of the divider  60  of FIG. 3 is cut or segmented. FIG. 5 best illustrates segments  74  of dunnage  101  wherein the pellicle of material is severed at  102  to leave three dividers  104  on rods  70 . 
     FIG. 6 illustrates a curtain type divider  110  where rod  70  and flange  72 , identical except for length to the like-numbered elements in FIGS. 3,  4  and  5 , extend through a tube  62  of the curtain material supporting curtain  112 . The opposing edge of curtain  112  is similarly formed into a tube structure  114  with weighting rod  116  inserted therein. Weighting rod  116  need only be heavy enough to maintain curtain  112  extended while in use. 
     The suspension rods  70  and flanges  72  of curtain  110  shown in FIG. 6 are preferably inserted into slots  50  having the lowest elevation relative to the erected height of collapsible shipping container  10 , as earlier mentioned; meanwhile, as illustrated in FIG. 5, the dunnage  101  is installed into and slides within those slots  50  having the highest elevation. This arrangement of the dunnage  101 ,  110  is shown in FIG.  7 . Thus, the support rods  70  of dunnage  101  in FIG. 5 will slide above rods  70  of dunnage  110  or curtains  110  creating smaller compartments or pouches  120  for the items being shipped. Weighting rod  116  will keep curtain  112  extended, thereby separating pouches  120 . 
     Whenever container  10  is collapsed as previously described for storage or return shipment the dunnage  101 ,  110  may be gathered and the dividers pulled upwardly and laid flat onto collapsed side panels  24 ,  26  and end panels  22 . 
     To prepare for usage, container  10  is erected and segments  74  of dunnage  101  lifted to permit spreading of curtains  110  across the interior of container  10 . When the curtains  110  are positioned as desired across container  10 , dunnage  101  may be spread and segments  74  dropped between curtains  110  to form pouches  120  as illustrated in FIG.  7 . 
     Dunnage  101  may be made to provide as many or as few segments  104  as desired and mated with an appropriate number of curtains  110  to form a matrix of separated pouches  120 , as illustrated in FIG.  7 . Further, curtains  110  may be made of a semi-rigid or rigid material if the material is thin enough to permit complete collapse of the container  10  and the items packed and transported will not be damaged by contact with the curtain material itself. 
     FIG. 7 illustrates a two-segment dunnage  101  with two severances or gaps  102 , orthogonally arranged relative to dunnage  101 , and is shown with a single dunnage curtain  110  residing in one gap  102 . The illustration of only a single curtain  110  is for purposes of clarity and simplicity. One of skill in the art will understand that an additional curtain will form two additional pouches and the number may be increased with additional segments  74  and curtains  110 . Accordingly, pouches  120  may be sized to accommodate any desired part or item for separated shipment. 
     Being reusable, the container  10  is very cost effective. Container  10  is particularly advantageous for the transport and shipment of electronic circuit boards if the material used for dunnage  100 ,  101 ,  110  is protective against electrostatic discharge and the dunnage  100 ,  101 ,  110  is maintained with the collapsible shipping container  10 , and protected by the collapsed shipping container  10  during periods of non-use and its return shipment to the prior shipper of the electronic circuit boards or other electronic devices. 
     With a change of dunnage material to fiber board, plastic sheeting or fabric, the container  10  may be adapted for shipment of mechanical parts or assemblies which do not require electrostatic discharge protection, but which require a more substantial divider yet may be collapsible within the container. 
     While each element of the assemblies shown in the several figures may not be described or addressed in respect to every figure, common reference numerals refer to common elements and the description of an element with regard to one figure may be applied to other figures in which a common element appears. 
     One of skill in the art will recognize that changes in the invention in addition to the various embodiments described herein may be made without removing the devices and system from the scope of protection afforded by the attached claims.