Collapsible containers
United States Patent Farnsworth *Apr. 1, 1975 COLLAPSIBLE CONTAINERS end panels with horizontal cleats mounted on the exte- [75] Inventor: William J. Famsvmrthq Mccomb rior of the panels and a plurality of swivel hinge cor- Miss. ner assemblies located at the corners of the collapsible container and secured to the cleats for pivotally con- Assigneer Altflmil Corporation, p li necting adjacent side panels and end panels to permit 1nd. the container to collapse. Each swivel hinge corner as- 1 Notice: The portion of the term of this sembly includes a pair of corner plates with each plate patent subsmluent to Apr. 1990, being secured to one of the cleats and having a prong has been disclaimed pro ecting laterally from one edge of the plate to overlap the prong projecting from the other plate. The  
 [ Filedi 1973 prongs of the corner plates are pivotally connected at [211 App! No: 330,273 a point spaced laterally from the edges of the corner plates to permit adjacent sides at opposite corners of Related pp i n Data the container to be folded either inwardly or out- [63] Continuation-impart of Ser. No. 115.302. Feb. 16. ardly to apse e conta E e panel and 1970, Pat. No. 3,729,111. end panel includes a plurality of spaced, parallel slats secured to the horizontal cleats with the slats at oppo- [52 U.S. Cl. 217/48, 217/16 site edges of the panels spaced laterally backward [51 Int. Cl B65d 9/14 from the ends of the cleats to accommodate the [58] Field of Search 217/16, 48 prongs of the swivel hinge corner assemblies. In addition, the collapsible container includes a hinged access [56] References Cited door extending across one of its panels and pivotally UNITED STATES PATENTS connected to adjacent sides of the container by a pair a) 7 of access door assemblies which permit the door to be 1:53:11? 2113;; ifii ii iii&#39;liIIIIIIIIIIIIIIIIIIIZ ill??? watched from the adjacent sides The door Primary Emminer-William 1. Price Assistant E,\&#39;uminerStephen P. Garbe Attorney, Agent, or FirmFinnegan, Henderson, Farabow &amp; Garrett [57] ABSTRACT A collapsible container is provided comprising a pair of rectangular side panels and a pair of rectangular assembly includes a pair of corner plates that are identical t0 the corner plates of the swivel hinge corner assembly and a spring catch for releasably engaging openings formed in the prongs of the corner plates to pivotally connect the prongs to permit the sides of the container to collapse and the corner plates to be unlatched.  
 14 Claims, 12 Drawing Figures Inn: All  
 PATENTEDAPR 1197s ATENTEB APR SHEET 3 BF 3 MwW w COLLAPSIBLE CONTAINERS The present application is a continuation-in-part of co-pending US. application Ser. No. 115,302, now U.S. Pat. No. 3,729,111, filed Feb. 16, 1970, and entitled Collapsible Containers lncluding Swivel Hinge Corner Assembly and Access Door Assembly.  
  The present invention relates to collapsible containers and, more particularly, to a collapsible container including a plurality of swivel hinge corner assemblies for connecting adjacent sides of the collapsible container to permit the sides of the container to collapse into a flat configuration.  
  1n the field of collapsible containers, it is necessary to provide a collapsible container that is very sturdy when set up and is also easily collapsed into a flat configuration for storage. In addition, it is preferred that the container be designed to collapse by folding adjacent sides at opposite corners of the container either inwardly or outwardly. Thus, it is desirable to provide a collapsible container including a plurality of swivel hinge corner assemblies for connecting adjacent sides of the collapsible container to provide a strong corner connection when the container is set up and to permit the sides of the container to collapse by folding the corners of the container in either direction.  
  In co-pending US. application Ser. No. 115,302, now US. Pat. No. 3,729,111 filed Feb. 16, 1970, a collapsible container including sides consisting of solid, rectangular side panels with a plurality of horizontal cleats extending across the side panels and a plurality of swivel hinge corner assemblies mounted at opposite ends of the horizontal cleats for pivotally connecting the sides of the container is disclosed. Each swivel hinge corner assembly comprises a pair of corner plates. Each corner plate includes a prong projecting laterally from its edge which overlaps the prong of the other corner plate. The prongs are pivotally connected to permit adjacent sides of the container to be folded outward or inward. Each of the side panels and end panels is cutaway at positions adjacent to the ends of the horizontal cleats for receiving the prongs projecting laterally from the corner plates. The application further discloses a preferred embodiment including a plurality of notches formed at opposite edges of each side panel and end panel for receiving the prongs. The present invention provides an alternative construction which eliminates the requirement of providing cutaway portions or notches in the side panels and end panels of the container.  
  In accordance with the present invention, a collapsible container includes a pair of rectangular side panels and a pair of rectangular end panels with opposite edges of the side panels being located adjacent to the edges of said end panels to provide the corners of the collapsible container, a plurality of horizontal side panel cleats mounted on the exterior of each end panel and aligned with the side panel cleats, and a plurality of swivel hinge corner assemblies located at each corner of the collapsible container for connecting adjacent side panels and end panels, each corner assembly comprising a first corner plate secured to a side panel cleat with a prong projecting laterally from one edge of the first corner plate toward the adjacent end panel, a second corner plate secured to an end panel cleat with a prong projecting laterally from one edge of the second corner plate toward the adjacent side panel and overlapping the prong of the first corner plate, and pivot means spaced laterally from the edges of the corner plates for pivotally connecting the prongs of the corner plates to permit the side panels and end panels of the container to collapse. Each of the side panels has its edges spaced laterally backward from the ends of the side panel cleats and each of the end panels has its edges spaced laterally backward from the ends of the end panel cleats to permit the prongs projecting from the first and second corner plates to overlap at the corner of the container.  
  In a preferred embodiment of the collapsible container, each side panel comprises a plurality of spaced, parallel slats with the slats at opposite edges of the side panel being spaced laterally backward from the ends of the side panel cleats and each end panel comprises a plurality of spaced, parallel slats with the slats at opposite edges of the end panel being spaced laterally backward from the ends of the end panel cleats. The backward spacing of the slats from the corners of the container permits the prongs of the corner plates to penetrate the interior of the container and overlap at the corners.  
  in the preferred embodiment, the first and second corner plates of each swivel hinge corner assembly are secured to horizontal surfaces of the side panel cleats and end panel cleats, respectively, with the edges of the first and second corner plates in abutting relation to exterior surfaces of the slats of the side panels and end panels, respectively. In addition, the pivot means of each swivel hinge corner is located at the vertex defined by the intersection of the planes of interior surfaces of the slats of the adjacent side panel and end panel to permit the panels to collapse inwardly or outwardly.  
  The collapsible container of this invention can be collapsed into a flat configuration by applying external pressures to the side panels and end panels of the container. A rectangular top panel and a rectangular bottom panel can be provided to form a closed container and to hold the side panels and end panels in a rectangular relationship when the container is set up. In addition, material held in the container will exert internal pressure on the side panels and end panels to maintain the container in its set-up condition.  
  The preferred embodiment can be provided with an access door extending across a side panel or end panel of the container. The access door may, for example, consist of an upper section of the side panel or end panel which is hinged to a lower section of the panel. The access door is pivotally connected to adjacent sides of the collapsiblecontainer by a pair of access door assemblies which permit the door to be unlatched from the sides of the container. Each access door assembly comprises a first corner plate secured to one side of the collapsible container with a prong projecting laterally from the first corner plate, a second corner plate secured to the access door of the collapsible container with a prong projecting laterally from the second corner plate and overlapping the prong of the first corner plate. The first corner plate of the access door assembly can be secured to a cleat mounted on an adjacent side of the container and the second corner plate can be secured to a cleat mounted on the door. The access door assembly also includes spring-biased pivot means for releasably engaging the prongs of the corner plates to pivotally connect the prongs to permit the sides of the container to collapse and the corner plates to be unlatched.  
  In the access door assembly of the preferred embodiment, openings are formed in the prongs of the first and second comer plates and spaced laterally from the edges of the corner plates, and the spring-biased pivot means comprises a spring catch mounted adjacent to one of the corner plates and including a cantilevered spring arm extending toward the prongs of the corner plates and a finger projecting from the cantilevered spring arm for normally engaging the openings formed in the prongs of the corner plates. With the finger in engagement with the openings in the prongs of the corner plates, the sides of the container can be collapsed by folding opposite corners of the container inwardly or outwardly. When the container is set up, the access door can be unlatched by appropriate operation of the spring catch.  
  The accompanying drawings illustrate presently preferred embodiments of the invention and, together with the description, serve to explain the principles of the invention.  
 Of the drawings:  
  FIG. 1 is a perspective view of the sides of a collapsible container constructed in accordance with the principles of this invention illustrating a pair of side panels including a plurality of spaced, parallel slats secured to horizontal side panel cleats, a pair of end panels including a plurality of spaced, parallel slats secured to horizontal end panel cleats, and a plurality of swivel hinge corner assemblies mounted on the cleats for pivotally connecting the side panels and end panels;  
  FIG. 2 is an enlarged perspective view of one corner of the collapsible container of FIG. 1, illustrating a swivel hinge corner assembly in detail and showing the relationship between the horizontal cleats and the slats located adjacent to the corner of the container;  
  FIGS. 3A and 3B illustrate first and second corner plates, respectively, of the swivel hinge corner assembly having prongs projecting laterally from the corner plates;  
  FIG. 4 is a side elevation view of the swivel hinge corner assembly illustrating the offset of the prongs of the corner plates;  
  FIG. 5 is a perspective view of the sides of the container of FIG. 1 in a collapsed configuration;  
  FIGS. 6A and 6B are plan views of a side panel and an end panel, respectively, of the collapsible container of FIG. 1 showing the backward spacing of the slats located at the opposite edges of the panels from the ends of the horizontal cleats;  
  FIG. 7 is a perspective view of the sides of a collapsible container provided with an access door hinged on one side of the container and incorporating a pair of access door assemblies which permit the sides of the container to be pivoted and the access door to be unlatched;  
  FIG. 8 is an enlarged perspective view of one corner of the collapsible container of FIG. 7, illustrating an access door assembly comprising a pair of corner plates and a spring catch;  
 FIG. 9 is a plan view of the spring catch of the access door assembly; and  
 FIG. 10 is a side view of the spring catch of the access principles of the present invention includes a pair of rectangular side panels and a pair of rectangular end panels with opposite edges of the side panels being located adjacent to the edges of the end panels to provide the corners of the collapsible container. In a preferred embodiment of the container, each side panel and end panel comprises a plurality of spaced, parallel slats. FIG. 1 illustrates the sides of a collapsible container 20 comprising a pair of rectangular side panels 22 and 24 including spaced, parallel slats 23 and 25, respectively, and a pair of rectangular end panels 26 and 28 including spaced, parallel slats 27 and 29, respectively. Opposite vertical edges of side panels 22 and 24 are located adjacent to the vertical edges of end panels 26 and 28 to provide the corners of collapsible container 20. Slats 23, 25, 27 and 29 of the side panels and end panels have planar exterior and interior surfaces, and the interior surfaces of the slats define the interior of container 20. A top panel and bottom panel (not shown) rectangular in shape can be provided to form a closed container.  
  In the collapsible container of this invention, a plurality of horizontal side panel cleats is mounted on the exterior of each side panel. Referring to FIG. 1, a plurality of horizonal side panel cleats 32 is mounted on the exterior surfaces of slats 23 of side panel 22. Similarly, a plurality of horizontal side panel cleats 34 is mounted on the exterior surfaces of slats 25 of side panel 24. In a preferred embodiment of the container, cleats 32 and 34 comprise a plurality of horizontal strips of rectangular cross section extending completely across the side panels.  
  The collapsible container of this invention also includes a plurality of horizontal end panel cleats mounted on the exterior surface of each end panel and aligned with the side panel cleats. Referring to FIG. 1, a plurality of horizontal cleats 36 is mounted on the exterior surfaces of slats 27 of end panel 26. Similarly, a plurality of horizontal end panel cleats 38 is mounted on the exterior surfaces of slats 29 of end panel 28. In the preferred embodiment of the container, horizontal cleats 36 and 38 comprise a plurality of horizontal strips of rectangular cross section extending completely across the end panels in vertical alignment with the horizontal strips on the side panels.  
  In addition, the collapsible container includes a plurality of swivel hinge corner assemblies located at each corner of the collapsible container for connecting adjacent side panels and end panels. As shown in FIG. 1, collapsible container 20 includes a plurality of swivel hinge corner assemblies 40 located at the corners of the collapsible container. The corner assemblies are secured to horizontal surfaces on the side panel and end panel cleats and, in the preferred embodiment, are secured to lower horizontal surfaces of cleats 32, 34, 36, and 38. FIGS. 2, 3, and 4 illustrate one swivel hinge corner assembly 40 in detail.  
  In accordance with the invention, each swivel hinge corner assembly for connecting adjacent side panels and end panels of a collapsible container to permit the sides of the container to collapse includes a first corner plate secured to a side panel cleat with a prong projecting laterally from one edge of the first corner plate toward the adjacent end panel. The swivel hinge corner assembly also includes a second corner plate secured to an end panel cleat with a prong projecting laterally from one edge of the second corner plate toward the 5 adjacent side panel and overlapping the prong first corner plate.  
  As embodied and shown in FIGS. 2 and 3, swivel hinge corner assembly 40 includes a first corner plate 42 having a generally rectangular, flat body 44 and a of the prong 46&#39;projecting laterally from a longitudinal edge 47 of the fiat body. A lateral edge 48 of flat body 44=is located adjacent to prong 46. k v  
 The first corner plate includes a pair ofv holes 49 formed in flat body 44 for receiving fasteners, sueh as a pair of screws (not&#39;shown) having enlarged screw heads, to secure the flat body to the lower horizontal a second corner plate S2( FIGS. 2 and 3) having a gen erallyrectangular, flat body 54 and a prong &#39;56 project ing laterally from a longitudinal edge 57 of the&#39;flat body. A lateral&#39;edge 58 of flat body 54 is located adjacent to prong As shown in FIG. 2, prong 56 fv the second corner plate overlaps prong 46 of the first corner plate&#34;. I  
  The second corner plate includes a pair of holes 59 formedin flat body 54 for receiving fasteners, such as a pair of screws (not shown) having enlarged screw heads, to secure the flat body to the lower horizontal surface of an end panel cleat, e&#39;.g., cleat Since the screws are inserted into the &#39;end panel cleat in a vertical direction, the holding power of the screws is at an angle of 90 to the internal pressure exerted on the&#39;int e&#39;rior surface of end panel 26 by material held, in &#34;the container. A 1  
  In the preferred embodiment, as shown in FIG. 2, flat body 44 of first corner plate 42 is secured to the side panel cleat with longitudinal edge 47 of the flat body in&#39; &#39;abutting relation with the exterior surface of slat 23 located at the edgeof&#39;side panel 22. Similarly, fiat body 54 of second corner plate 52 is secured to the endpanel cleat with longitudinal edge 57 of the flat body in abutting relation with the exterior surface of slat 27 located at the edgeof end panel 26. I l  
  Referring to FIG. 4, prong 46 0f first corner plate 42 is substantially planar and aligned in a plane parallel to flat body 44 of the first corner plate. This prong is offset by one-half of the thickness of the corner plate&#39;from flat body 44. Similarly, prong 56 o&#39;f second corner plate 52 is substantially planar and aligned in a plane parallel toflat body 54 ofthe second corner plate. The prong is offset by one-half of the thickness of the corner plate from flat body 54. The pjro&#39;ngs are offset to permit flat bodies 44 and 54 oftlie corner plates to be&#39;c o-planar when the flat bodies are&#39;secured to&#39;side panel and end panel cleats mounted on &#39;adja&#39;cent sides of the collapsible Container;  
 In the collapsible container of this invention, the 60 swivel hinge corner assembly also includes pivot means Referring to FIG. 3, an opening 60 is formed in prong 46 of the first corner plate and is spaced laterally from longitudinal edge 48 of flat body 44 of the first corner plate by a distance 0&#39;. Opening 60 is also located in tainer.  
 alignment with lateral edge 48 of the fiat body. Similarly, an opening 62 is formed in-prong 56 ofthe second corner plate and spaced laterally from longitudinal edge 57 of flat body 54 by a distance d. Opening 62 is also located in alignment with laterial edge 58 of the flatbody. As embodied and shown in&#39;FIG. 2, the pivot means comprises a hinge pin or rivet 64 inserted into openings 60 and 62,formed in prongs 46 and 56 to pivotally connect the first andsecond corner plates to permit &#34;the corner-plates to pivot&#39;about the hinge pin to collapse the side panels and end panels of the con- The plurality of swivelhinge corner assemblies 40 permits collapsible containers to be collapsed by folding the adjacent sides at opposite corners of the spaced laterallyfrom the edges of the corner plates for pivotally&#39; connecting the prongs of the corner plates to permit the, side panels and end&#39;panels of the container to, collapse. .&#39;ln the preferred embodiment, the pivot means is located at the intersection offthe planes of the interior surfaces of the adjacent side panel and end panel.  
 container inwardly or outwardly. As shown in FIG. 5, side panel 22 can be foldedinwardly toward end panel 28; and side panel 24 can be folded inwardly toward .end ,panel 26 to move the sides of the container to the collapsed configuration. Alternatively, side panel 22 can be folded inwardly toward end panel 26, and side panel 24 can be folded inwardly toward end panel 28 4 toachlve the collapsed configuration. Thus, the swivel between the&#34; longitudinal edges of its corner plates when the container is collapsed by folding side panel 24 toward end panel 26&#39;. Thus, it is preferred that the distance be equal to the thickness of the slats of the side panels and end panels of the container.  
  Further, each swivel hinge corner assembly connecting end panel26 to side panel 22 must permit the panels to be folded outwardly to a position where the panels are&#34; 180 apartThe location of openingsand 62 formed in the prongs of the first and second corner plates in alignment with lateral edges 47 and 57, respectively, of the flat bodies of the corner plates and the offset of the prongs by one-half of thethickness of the corner plates permit each swivel hinge corner assembly to open to an angle of tocollapse the con- In. accordance with the invention, each of the side panels ,has its&#39;edges laterally backward from the ends of side panel cleats and .each of the end panels has itsedges spaced laterally backward from the ends of the end panel cleats&#39;to permit the prongs projecting from the first and second corner plates to overlap at the corners of the container. In the preferred embodiment, each of the slats located at the opposite. edges of each side panel is spaced laterally backward from the ends of the side panel cleats to permit the prongs of the first corner plates to penetrate the interior of the container, and each of the slats located at the opposite edges of each end panel is spaced laterally backward from the ends of the end panel cleats to permit the prongs of the second corner plates to penetrate the interior of the container.  
  Referring to FIG. 1, slats 23 and 25 of side panels 22 and 24, respectively, and slats 27 and 29 of end panels 26 and 28, respectively, which are located adjacent to the corners of container are spaced backward from the corners along the corresponding side panel and end panel cleats to permit the prongs of swivel hinge assemblies 40 to overlap at the corners of the container. As shown in FIG. 2, for example, slat 23, which is located at the edge of side panel 22 adjacent to the corner provided by side panel 22 and end panel 26, is spaced laterally backward from the end of horizontal cleat 32 to provide sufficient spacing to accommodate prong 46 of first corner plate 42. Similarly, slat 27, which is located at the edge of end panel 26, is spaced laterally backward from the end of end panel cleat 36 to accommodate prong 56 of second corner plate 52. Referring to FIG. 6, slats 23 located at the opposite edges of side panel 22 are spaced laterally backward from the opposite ends of side panel cleats 32, and slats 27 located at the opposite edges of end panel 26 are spaced laterally backward from the opposite ends of end panel cleats In the preferred embodiment, the slats are spaced latcrally backward from the ends of the corresponding horizontal cleats by approximately one-half inch. The backward spacing of the slats at the edges of the side panels and end panels permits the prongs of the corner plates to penetrate into the interior of container 20 when the container is set up. The slat spacing eliminates the need for providing cutaway portions or notches in the side panels and end panels to receive the prongs of the corner plates.  
 It is understood that, although the preferred embodiment of the invention is concerned with a collapsible container in which the side panels and end panels comprise a plurality of spaced, parallel slats, the invention is equally applicable with a container including solid rectangular panels. In the case of solid panels, the opposite edges of the panels adjacent to the corners of the container are spaced backward from the ends of the horizontal cleats to accommodate the prongs of the corner plates.  
 I FIG. 7 illustrates the sides of a collapsible container 70 constructed according to the principles of this invention which includes an access door located on one side of the container. The construction of collapsible container 70 is similar to the construction of collapsible container 20 (FIG. 1) and, accordingly, the structural elements of container 70 which are identical to the elements of container 20 are identified by the same reference numerals used in FIG. 1.  
  Collapsible container 70 includes rectangular side panels 22 and 24 including a plurality of spaced, parallel slats 23 and 25, respectively, with side panel cleats 32 and 34, respectively, mounted on the exterior surfaces of the slats of the side panels. Slats 23 and located adjacent to the corners of the container are spaced laterally backward from the ends of the side panel cleats. In addition, the collapsible container includes rectangular end panels 26 and 28. End panel 28 comprises a plurality of spaced, parallel slats 29 with end panel cleats 38 mounted on the exterior surfaces of the slats. Slats 29 located at the opposite edges of end panel 28 are spaced laterally backward from the ends of end panel cleats 38. Side panels 22 and 24 and end panels 26 and 28 are pivotally connected at the edges of the panels by a plurality of swivel hinge corner assemblies 40 to permit the container to be collapsed.  
  As shown in FIG. 7, end panel 26 of collapsible container consists of an upper rectangular section 72 including a plurality of spaced, parallel slats 73 and a lower rectangular section 74 including a plurality of spaced, parallel slats 75. The lower rectangular section includes a plurality of end panel cleats 36 mounted on the exterior surfaces of slats 75. Slats 73 and slats 75 located at the opposite edges of end panel 26 are spaced laterally backward from the ends of the end panel cleats. Lower rectangular section 74 is pivotally connected to side panels 22 and 24 of the container by swivel hinge corner assemblies 40 secured at opposite ends of end panel cleats 36 and to corresponding side panel cleats 32 and 34 on the side panels.  
  In collapsible container 70, upper rectangular section 72 of side panel 26 provides a door for the collapsible container. As shown in FIG. 7, a lower edge of the door&#39; extends horizontally across lower section 74 of the side panel. A horizontal cleat 76 is mounted on the exterior surfaces of slats 73 of the door at its lower edge, and an end panel cleat 36 is mounted at the upper edge of the door in alignment with side panel cleats 32 and 34 on the side panels.  
  The collapsible container includes hinge means for connecting the lower edge of the door to the side panel to permit the door to be pivoted outward to an open position relative to the container. In collapsible container 70 (FIG. 7), the hinge means comprise a plurality of hinges 78 secured to cleat 76 and end panel cleat 36 at the upper edge of lower rectangular section 74 to pivotally connect the door to the lower rectangular section.  
  The collapsible container also includes a pair of access door assemblies which are located at the corners of the container adjacent to the upper edge of the door for pivotally connecting the door to adjacent sides of the container and permitting thedoor to be unlatched from the adjacent sides. As embodied and shown in FIG. 7, collapsible container 70 includes a pair of ac cess door assemblies 80 located at opposite ends of end panel cleat 36 mounted on the upper edge of the door. FIG. 8 illustrates one access door assembly 80 in detail.  
  The access door assembly includes a first corner plate secured to one side of the collapsible container with a prong projecting outwardly from one edge of the first corner plate. In addition, the access door assembly including a second corner plate having secured to the door of the collapsible container with a prong projecting laterally from one edge of the second corner plate and overlapping the prong of the first corner plate. As shown in FIG. 8, access door assembly 80 includes a first corner plate 82 which is identical to corner plate 42 of swivel hinge corner assembly 40 (FIGS. 2, 3,and 4). Referring to FIG. 8, corner plate 82 includes a generally rectangular, flat body 84 and a prong 86 projecting laterally from a longitudinal edge 87 of the flatbody. A lateral edge 88 of flat body 84 is located adjacent to prong 86.  
  In the preferred embodiment. an opening (identical to opening 50 formed in prong 46 of corner plate 42 shown in FIG. 3) is formed in prong 86 of corner plate 82 and is spaced laterally from longitudinal edge 87 of flat body 94 of the corner plate. This opening is also located in alignment with lateral edge 88 of flat body 84.  
  Similarly, access door assembly 80 (FIG. 8) includes a second corner plate 92 which is identical to corner plate 52 of swivel hinge corner assembly (FIGS. 2, 3. and 4). Referring to FIG. 8, second corner plate 92 includes a generally rectangular. flat body 94 and a prong 96 projecting laterally from a longitudinal edge 97 of the flat body. Prong 96 of the second corner plate overlaps prong 86 of the first corner plate.  
  In the preferred embodiment, an opening (identical to opening 60 formed in prong 56 of corner plate 52 shown in FIG. 3) is formed in prong 96 of corner plate 92 and is spaced laterally from longitudinal edge 97 of flat body 94 of the corner plate. This opening is also located in alignment with lateral edge 98 of flat body 94.  
  Referring to FIG. 8, prongs 86 and 96 of the first and second corner plates of access door assembly 80 are substantially planar and aligned parallel to flat bodies 84 and 94, respectively. of the corner plates. The prongs are offset by onehalf of the thickness of the corner plates to permit the flat bodies of the corner plates to be co-planar when the access door assembly is mounted on the collapsible container.  
  The access door assembly of this invention includes releasable pivot means spaced laterally from the edges of the flat bodies of the first and second corner plates for releasably engaging the prongs of the corner plates to pivotally connect the prongs to permit the sides of the container to collapse and the corner plates to be unlatched. In a preferred embodiment. the releasable r pivot means comprises a spring catch mounted adjacent to one of the corner plates including a cantilevcred spring arm extending toward the prongs of the corner plates and a finger projecting from the cantilevercd spring arm for normally engaging openings formed in the prongs ofthe corner plates. Alternatively. the releasable pivot means may comprise a removable pin inserted in the openings provided in the prongs of the corner plates.  
  As embodied and shown in FIG. 8, access door assembly 80 includes a spring catch 100 comprising a spring arm 102 extending toward prongs 86 and 96 of the corner plates. Spring arm 102 is provided with a finger I04 projecting upward from one end of the spring arm for normally engaging the openings formed in prongs 86 and 96. The opposite end of spring arm 102 includes a U-shaped section 106 to enable the spring arm to be mounted adjacent to corner plate 84 of the access door assembly. as explained below.  
  Corner plates 82 and 92 can be secured to cleats of the collapsible container by conventional fasteners, such as screws or bolts. As shown in FIG. 8, a pair of holes 108 and 110 are formed in flat body 84 of first corner plate 82, and a pair of holes 112 and 114 are formed in flat body 94 of second corner plate 92. The corner plates can be secured to cleats 32 and 36 by inserting a plurality of screws (not shown) having enlarged screw heads into the cleats through openings 108, 110. I12, and 114 in the flat bodies. 7  
  Spring arm 102 can be mounted adjacent to first corner plate 82 by placing U-shaped section 106 of the spring arm around opening 108 and then inserting one of the screws into cleat 32 through the opening. The  
 enlarged head of the screw will clamp the U-shaped section of spring arm 102 against&#39;flat body 84 of the corner plate. In addition, another screw can be driven into cleat 32 at a position inside U-shaped section 106 adjacent to the curved portion of the U-shaped section to clamp this curved portion against the cleat.  
  As shown in FIG. 10, the curved portion of U-shaped section 106 of spring arm 102 is bent slightly upward from the spring arm. When U-shaped section 106 is clamped against cleat 32 and flat body 84 of corner plate 82, the curved portion of the U-shaped section is flattened out to produce a spring tension in spring arm 102 to urge finger 104 upward so that it normally engages the openings formed in prongs 86 and 96 to pivotally connect corner plates 82 and 92. In addition. spring arm 102 is formed with a bend 116 (FIGS. 8 and 9) extending away from prongs 86 and 96 of the corner plates to permit finger 104 to be disengaged from the openings formed in the prongs by pressing downward on bend 116.  
  Referring to FIG. 7, each access door assembly 80 serves the same function as swivel hinge corner assemblies 40 when the spring catch of the access door assembly engages the openings formed inthe prongs of the corner plates. Thus. collapsible container can&#39;be fully collapsed by folding the sides at opposite corners of the container inwardly or outwardly. When container 70 is set up, however, access door assemblies permit the door of the container-to be unlatched and pivoted outward relative to the interior of the container. The door can be unlatched by pressing downward on the bends formed in the spring arms of the access door assemblies to unlatch the corner plates secured to horizontal cleat 36 of the upper edge of the door from the corner plates secured to cle&#39;ats 32 and 34 on the adjacent sides of the container.  
  The invention in its broader aspects is not limited to the specific details shown and described. and modifications may be made in the details of the collapsible container without departing from the principles of the present invention.  
 What is claimed is:  
 l. A collapsible container comprising:  
 a pair of rectangular side panels and a pair of rectangular&#39;end panels, each side panel having opposite edges located adjacent to the edges of said end panels to provide the corners of the collapsible container;  
 a plurality of horizontal side panel cleats mounted on the exterior of each side panel; I  
 a plurality of horizontal end panel cleats mounted on the exterior of each end panel, said end panel cleats being aligned with said side panel cleats; and  
 a plurality of swivel hinge corner assemblies located at each corner of the collapsible container for connecting adjacent side panels and end panels, each corner assembly comprising a first corner plate secured to a side panel cleat with a prong projecting laterallyfrom one edge of said first corner plate toward the adjacent end panel.  
 a second corner plate secured to an end panel cleat with a prong projecting laterally from one edge of said second corner plate toward the adjacent side panel and overlapping the prong of said first corner plate, and  
  pivot means spaced laterally from the edges of said corner plates for pivotally connecting said prongs of said corner plates to permit said side panels and end panels of the container to collapse: each of said side panels having its edges spaced laterally backward from the ends of said side panel cleats and each of said end panels having its edges spaced laterally backward from the ends of said end panel cleats to permit the prongs projecting from the first and second corner plates to overlap at the corners of the container. 2. The collapsible container of claim 1. wherein said pivot means is located at the intersection of the planes of the interior surfaces of the adjacent side panel and end panel.  
 3. The collapsible container of claim 1. wherein:  
 each side panel comprises a plurality of spaced. parallel slats with the slats at opposite edges ofthe side panel being spaced laterally backward from the ends of the side panel cleats; and  
 each end panel comprises a plurality of spaced. parallel slats with the slats at opposite edges of the end panel being spaced laterally backward from the ends of the end panel cleats.  
 4. The collapsible container of claim 1. wherein:  
 each of said side panel cleats is a horizontal strip of rectangular cross section extending completely across the side panels; and  
 each of said end panel cleats is a horizontal strip of rectangular cross section extending completely across the end panels.  
 5. The collapsible container of claim 4, wherein said corner plates are secured to lower surfaces of the horizontal strips mounted on said side panels and end panels.  
 6. The collapsible container of claim 1. wherein:  
 said prongs of said first and second corner plates have openings formed therein and spaced laterally from the edges of said corner plates; and said pivot means comprises a hinge pin inserted into said openings to pivotally connect said first and second corner plates to permit said corner plates to pivot about said hinge pin to collapse said side panels and end panels of the container.  
 7. The collapsible container of claim 1, wherein:  
 said prongs of said first and second corner plates are parallel and offset by one-half of the thickness of said corner plates to permit said corner plates to be co-planar.  
 8. A collapsible container comprising:  
 a pair of rectangular side panels and a pair of rectangular end panels. each side panel including a plurality of spaced. parallel slats having planar exterior and interior surfaces and a plurality of horizontal side panel cleats mounted on the exterior surfaces of the slats of each side panel. and each end panel including a plurality of spaced. parallel slats having planar exterior and interior surfaces and a plurality of horizontal end panel cleats mounted on the exterior surfaces of the slats of each end panel. said end panel cleats being aligned with said side panel cleats; and  
 a plurality of swivel hinge corner assemblies for connecting adjacent side panels and end panels. each corner assembly comprising a first corner plate secured to aside panel cleat with a prong projecting laterally from one edge of said first corner plate toward the adjacent end panel.  
 i a second corner plate secured to an end panel cleat with a prong projecting laterally from one edge of said second corner plate toward the adjacent side panel and overlapping the prong of said first corner plate. and  
  pivot means spaced laterally from the edges of said corner plates for pivotally connecting said prongs of said corner plates to permit said side panels and end panels of the container to collapse; each of the slats located at the opposite edges of each side panel being spaced laterally backward from the ends&#39; of said side panel cleats to permit the prongs of said first corner plates to penetrate into the interior of the container; and  
 each of the slats located at the opposite edges of each end panel being spaced laterally backward from the ends of said end panel cleats to permit the prongs of said second corner plates to penetrate into the interior of the container and overlap the prongs of said first corner plates.  
 9. The collapsible container of claim 8. wherein:  
 said prongs of said first and second corner plates have openings formed therein and spaced laterally from the edges of said corner plates located at the vertex defined by the intersection of the planes of the interior surfaces of the slats of adjacent side panels and end panels; and said pivot means comprises a hinge pin inserted into said openings to pivotally connect said first and second corner plates to permit the corner plates to pivot about said hinge pin to collapse said side panels and end panels of the container.  
 10. The collapsible container of claim 8. which includes:  
 a door having an upper edge and a lower edge extending horizontally across one of said panels;  
 hinge means for connecting the lower edge of said door to said panel to permit said door to be pivoted outward to an open position relative to the container; and  
 a pair of access door assemblies located at the corners of the container adjacent to the upper edge of said door for pivotally connecting said door to adjacent panels of the container and permitting said door to be unlatched from the adjacent panels.  
 11. The collapsible container of claim 10, wherein each access door assembly comprises:  
 a first corner plate secured to one of the panels located adjacent to said door with a prong projecting laterally from one edge of said first corner plate toward the door.  
 a second corner plate secured to said door with a prong projecting laterally from one edge of said second corner plate toward said one of the adjacent panels and overlapping the prong of said first corner plate. and  
 spring-biased pivot means spaced laterally from the edges of said first and second corner plates for releasably engaging said prongs of said corner plates to pivotally connect said prongs and permit the sides of the container to collapse.  
 12. The collapsible container of claim 11, wherein:  
 said cantilevered spring arm includes a bend extending away from said prongs of said corner plates to permit said finger to be disengaged from said openings by pressing on said bend.  
 14. The collapsible container of claim 12., wherein: said prongs of said first and second corner plates are parallel and offset by one-half of the thickness of said corner plates to permit said corner plates to be co-planar.  
  UNITED STATES PATENT OFFICE 9 CERTIFICATE OF CORRECTION Patent No. 3374543 Dated April 1, 1975 Inventor-( William J. Farnsworth It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:  
 On the title page of the patent, under the heading I &#34;Related U.S. Application Data&#34; change &#34;Feb. 16, 1970&#34; to Feb. 16, 1971 Column 1, line 3, change &#34;Feb. 16, 1970&#34; to Feb. 16, 1971 Column 1, line 28, change &#34;Feb. 16, 1970&#34; to Feb. 16, 1971 Signed and sealed this 10th day of June 1975.  
 (SEAL) Attest C. MARSHALL DANN RUTH C. MASON Commissioner of Patents Attesting Officer and Trademarks