Abstract:
An environmentally sealable plastic shipping container is provided that includes a main container cover and body portion fabricated of a set of plastic extrusions and end caps, connected by tenon-type joints facilitating construction using commercially available adhesives and optional aluminum extrusions with commercially available mechanical fasteners where desirable for rapid opening or closing.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority of the filing date of Provisional Application Ser. No. 60/340,515 filed 14Dec. 2001, the contents of which are incorporated by reference herein. 

   RIGHTS OF THE GOVERNMENT 
   The invention described herein may be manufactured and used by or for the Government of the United States for all governmental purposes without the payment of any royalty. 

   BACKGROUND OF THE INVENTION 
   The present invention relates generally to reusable shipping containers, and more particularly to an improved reusable shipping container having environmentally sealable modular construction. 
   Environmentally sealed shipping containers known in the prior art have found substantial use in protecting commercial products under long term storage or in transport under environmentally challenging conditions. The prior art containers typically are constructed of fiberglass, rotationally molded plastic, injection molded plastic, blow molded plastic or welded metal, preferable reusable, and are used in applications in which the protected product may be sensitive to temperature, humidity or other environmental hazards. 
   Examples of relevant prior art packaging and shipping containers include those disclosed in U.S. Pat. No. 2,893,588 to Martin wherein a drawn sheet of metallic or plastic material pallet is used as the base of a heavy-duty container, in U.S. Pat. No. 4,050,604 to Flanders and U.S. Pat. No. 5,170,933 to Perry disclosing disassemblable reusable containers, and U.S. patent U.S. Pat. No. 5,287,970 to Weidt for a plastic container having pocket-like free spaces. Other reusable containers in the prior art are typically of a heavy metallic construction or are limited to certain specific sizes because of the limitations on the plastic molding processes. 
   The invention solves or substantially reduces in critical importance problems with previously existing reusable shipping containers by providing an environmentally sealable plastic shipping container having a main container cover and base comprising a set of plastic extrusions and end caps, connected by tenon-type joints facilitating construction using commercially available adhesives and optional aluminum extrusions with commercially available mechanical fasteners where desirable for facilitating rapid opening or closing of the container. The container of the invention may be constructed of substantially any size and rectangular geometry without special molds or tooling. When the container is no longer suitable for its intended purpose, the plastic material of which the container is constructed can be recycled by returning the container to a reprocessing facility for melting or regrinding the plastic for reuse. 
   It is therefore a principal object of the invention to provide an improved environmentally sealable reusable shipping container. 
   It is another object of the invention to provide an environmentally friendly shipping container. 
   It is yet another object of the invention to provide a container easily fabricated to any desired size using standard hardware and no special tools. 
   It is yet another object of the invention to provide an environmentally sealable container having substantially standard component part configurations and may be fabricated to substantially any size using standard parts. 
   It is a further object of the invention to provide a container whose structural material can be reground and recycled and reused or remanufactured as a container defined by the invention. 
   These and other objects of the invention will become apparent as a detailed description of representative embodiments proceeds. 
   SUMMARY OF THE INVENTION 
   In accordance with the foregoing principles and objects of the invention, an environmentally sealable plastic shipping container is provided that includes a main container cover and body portion fabricated of a set of plastic extrusions and end caps, connected by tenon-type joints facilitating construction using commercially available adhesives and optional aluminum extrusions with commercially available mechanical fasteners where desirable for rapid opening or closing. 

   
     DESCRIPTION OF THE DRAWINGS 
     The invention will be more clearly understood from the following detailed description of representative embodiments thereof read in conjunction with the accompanying drawings wherein: 
       FIG. 1  is a perspective view of a representative embodiment of the container of the invention; 
       FIG. 2  is a perspective view in cutaway of one corner of the base of the container of  FIG. 1 , showing the structure of the corner elements and edge extrusion elements of the  FIG. 1  container; 
       FIG. 3  is a perspective view of a segment of a comer post and a portion of a side element of the container of  FIG. 1  illustrating the assembly of the sides and corners of the  FIG. 1  container; 
       FIG. 4  is a perspective view of an upper corner of the base of the container of  FIG. 1  showing the structure that interfaces the lid of the container; and 
       FIG. 5  is a perspective view in cutaway of one comer of the cover of the container of  FIG. 1 , showing the structure of the comer elements and edge extrusion elements of the cover. 
   

   DETAILED DESCRIPTION 
   Referring now to the drawings,  FIG. 1  shows a schematic perspective view of a representative embodiment of container  10  described and claimed herein. Container  10  of the invention is generally rectangular in shape and includes a base or body portion  11  having and four sides  12 , 13 , 14 , 15 , the sides comprising respective rectangular flat panels  16   a-d  all interconnected by corner posts  20   a-d  described in more detail in relation to drawing figures hereinafter presented. Lid or cover  18  for container  10  comprises a rectangular panel  24  and includes corner elements  25   a-d  and edge elements  26   a-d  also described below in relation to drawings figures hereinafter presented. 
   Referring now to  FIG. 2 , shown therein is a perspective view in cutaway of one lower corner of body portion  11  of container  10 . Body portion  11  includes four corner elements  31   a-d,  four edge elements  32   a-d  and flat panel  33  defining the bottom of container  10 . Each edge clement  32   a-d  is structured to be a hollow extrusion of substantially any selected length depending on the intended size and shape of container  10  in the final assembled condition. Longitudinal slot  34   a  is defined in each element  32  in order to snugly receive the bottom panel  33  in the assembled condition. A second longitudinal slot  34   b  is defined in the top of each extruded edge element  32  to snugly receive a flat panel  16  defining a side to container  10  in the assembled condition. Corner elements  31  are identical to each other and include a pair of tongue elements or tenons  35   a,b  on adjacent edges of corner element  31 , the tenons being sized to be snugly received in the assembled condition by the slot  36  formed in each extruded edge element  32   a-d,  thereby substantially forming tenon/mortise joints at each corner. Raised rectangular portion or flat  34  is defined in the top surface  35  of each corner element  31  for receiving one of the corner posts  20   a-d  as described below in relation to FIG.  3 . 
   Referring now to  FIG. 3 , shown therein is a perspective view of a segment of one of the corner posts  20   a-d  and a portion of one of the side elements  16   a-d  illustrating the assembly of panels  16   a-d  to the four corner posts  20   a-d  as suggested in FIG.  1 . Each corner post  20   a-d  is structured to be a hollow extrusion of substantially any selected length depending on the intended size and shape of container  10  in the final assembled condition. Each corner post  20   a-d  also includes means defining a pair of longitudinal slots  21   a,b  on adjacent surfaces of each post  20   a-d  as suggested in  FIG. 3  for receiving two of the panels  16   a-d  defining adjacent sides of body portion  11  in the assembled condition as suggested in FIG.  1 . The opening  22  in each extrusion defining a corner post  20  is sized to snugly receive a raised portion  36  in a corner element  31  in body portion  11 . 
   Referring now to  FIG. 4 , shown therein is a perspective view in partial cutaway of one corner of the top of body portion  11  of container  10 . Four substantially identical corner elements  41  are configured similarly to corner elements  31  including a raised portion or flat  42  on the bottom of each corner element  41  and sized to snugly fit into the top of the respective extrusions  20  defining the corner posts of body portion  11 . Four edge elements  44  are structured as hollow extrusions similar to edge elements  32  of FIG.  2 . Tenons  45  (shown in phantom) on adjacent surfaces of each corner element  41  are sized to snugly fit into the slot defined by edge elements  44  in like manner to the tenon/mortise structure of corner elements  31  and edge elements  32  of the  FIG. 2  structure. Elements  44  are sized in correspondence with the selected size of elements  32  to form the container  10  of the desired size and shape. Longitudinal slot  47  is defined in bottom of each element  44  in manner similarly to element  32  above in order to snugly receive a flat panel  16  defining a side to container  10  in the assembled condition. Peripheral groove  48  is defined in the upper surfaces of each of the corner elements  41  and extruded edge elements  44  substantially as shown and extends around the entire periphery of the upper surface of body portion  11 . Gasket  49  may be provided in groove  48  for providing a seal with the cover for container  10  as described below in relation to FIG.  5 . Two or more latches  50  may be attached in any suitable manner to each edge element  44  substantially as shown in order to tightly attach the cover of container  10  to body portion  11 . Latches  50  may be of any commercially available type suitable for attaching the lid to body portion  11 , the specific latch selection not considered limiting of the invention. The number of latches attached on each side of container  10  may be selected by the skilled artisan practicing the invention depending on the size selected for container  10 . 
   Referring now to  FIG. 5 , shown therein is a perspective view in cutaway of one corner of cover  18  of the representative container  10  of FIG  1 , showing the structure of the corner elements  25   a-d  and extruded edge elements  26   a-d.  Similar to the edge elements  32  of  FIG. 2 , each edge element  26   a-d  is structured as a hollow extrusion of substantially any selected length, corresponding to the respective lengths of edge elements  32   a-d  of  FIG. 2 and 44   a-d  of FIG.  4  and depending on the intended size and shape of container  10  in the final assembled condition. Longitudinal slot  28  is defined in each element  26   a-d  in order to snugly receive the top panel  24  in the assembled condition. Corner elements  25  are identical to each other and, similarly to corner elements  31  of  FIG. 2 , include a pair of tenons  29   a,b  on adjacent edges of corner element  25  sized to be snugly received in the assembled condition by the slot  30  formed in each extruded edge element  26   a-d,  thereby substantially forming tenon/mortise joints at each corner. The lower surfaces of edge elements  26   a-d  and corner elements  25   a-d  are preferably smooth and continuous so that a seal between cover  18  and body portion  11  at gasket  48  is accomplished upon assembling container  10 . In an alternative configuration, the top surfaces of edge elements  44  and corner elements  41  may present a smooth continuous surface for sealing to a gasket (not shown) provided in a groove (also not shown) in the lower surfaces of edge elements  26  and corner elements  25  of cover  18 . 
   It is preferable that the extrusion defining each edge element  26   a-d of  cover  18  include a flange  51  in order to provide means for latching cover  18  to body portion  11  in the assembled condition shown in FIG.  1 . Notch  53  may be provided at positions along flange  51  corresponding to the locations of latches  50  on body portion  11  in order to releasably secure cover  18  to body portion  11  using the latch type illustrated in FIG.  1 . It is, however, noted that other conventional latch types may be used, such as a simple clamp structure (not shown) attaching body portion  11  to cover  18  at flange  51  wherein notch  53  may not be required. 
   A significant advantage of the container structure disclosed and claimed herein is that edge elements  32   a-d  may be fabricated from a single extrusion and cut to the appropriate length(s) corresponding to the desired size of the container. Similarly, corner posts  20   a-d,  edge elements  44   a-d,  and edge elements  26   a-d  may be fabricated from the respective extrusions and cut to the appropriate length(s) for the desired container structure size and configuration. Additionally, in certain configurations, certain extruded structural elements of the assembled container may be substantially identical. For example, a container could be configured wherein extrusions for corner posts  20  and edge elements  32  and  44  could be identical with minor machining needed on one of the extrusions for completion of the structure. Accordingly, a small number of extrusion structures would be required to structure a container of substantially any desired size. Each corner element  31   a-d,    41   a-d  and  25   a-d  may be fabricated using conventional molding (such as injection or compression molding) and/or machining processes. One minor advantage of the corner structures just described is that the extrusions and corner elements could be sized such that the corner elements could be molded substantially identically with only minor finish machining being required on corner elements  25 . The materials of construction for the component parts of the container, including all extrusions, corner elements and flat panels, may be selected by one skilled in the art guided by these teachings and preferably include plastics, such as polyvinyl chloride (PVC), chlorinated PVC (CPVC), or other extrudable materials such as styrene, polyethylene, or polypropylene, the specific selected material not considered limiting of the invention disclosed and claimed herein. In the assembled condition for the container, all joints may be preferably bonded together and hermetically sealed using commercially available adhesive, such as cyanoacrylate epoxy, silicone adhesive, or plastic weld adhesives for the plastic materials and similar adhesives for other candidate extrudable materials. 
   Addition of pressure relief valves, desiccant ports, humidity indicators, or other commercially available hardware (not shown) may be added to the structure of the container of the invention in order to facilitate a wide variety of uses for the invention. 
   The invention therefore provides an improved environmentally sealable shipping container. It is understood that modifications to the invention may be made as might occur to one with skill in the field of the invention within the scope of the appended claims. All embodiments contemplated hereunder that achieve the objects of the invention have therefore not been shown in complete detail. Other embodiments may be developed without departing from the spirit of the invention or from the scope of the appended claims.