Abstract:
A collapsible container is formed by folding a twolayer blank having a unitary flexible layer and a separated rigid layer into a shape determined by the number of side panels of the blank. The container is held in the assembled position by fastened corresponding pairs of fasteners on adjacent side panels. The flexible and rigid layers are joined together by lamination and/or stitching. The containers are reversible, so that either the rigid or flexible layer may be exposed on the outside of the assembled container.

Description:
FIELD AND BACKGROUND OF THE INVENTION 
     The present invention relates generally to the field of collapsible containers and in particular to a new and useful folding container formed from conjoined rigid and flexible layers for holding solid items. 
     Collapsible or knockdown trays and boxes and other containers are useful for temporarily holding a variety of items. Collapsible trays and boxes are more easily stored than fixed-panel containers since they can take up less space. At the same time, when assembled, some collapsible containers can have comparable strength to fixed, rigid containers. 
     Materials known for use in making collapsible containers include paper materials in particular, such as cardboard, cardstock and coated papers. 
     Multi-layer paneled containers are generally disclosed in the art, such as by U.S. Pat. No. 5,230,689 for a flexible container for holding flowable materials. The patent teaches forming the walls of the container by removably inserting a rigid panel inside pockets created by two flexible layers. The rigid panels are not fixed in the pockets. The patent does not disclose what material is used to make the flexible or rigid layers. 
     Other patents disclose folding containers, such as U.S. Pat. No. 241,254 for a folding tray having a base panel, two side panels and two end panels. The side panels include end projections which fold over the adjacent end panel when the tray is assembled. The patent discloses that it is known to secure the end projections using wire staples, tacks, eyelets. The tray uses an adhesive on a strip of wood veneer, paper or fabric secured to the end panels to hold the end projections in place. The tray may be made of a thin wood veneer or pasteboard. 
     A tray made by folding a flexible sheet is disclosed by U.S. Pat. No. 798,264. A pie-shaped unitary blank has scored corner sections for folding up side panels of the blank to form a pie-shaped tray. The rear wall of the blank is slit so that the panel may be folded up to form the curved wall. The corners of the folded blank may be secured using glue applied to the folds of the corners. 
     U.S. Pat. No. 2,006,811 discloses a triangular cardboard blank for folding into an ash tray. The side panels of the ash tray fold upwardly and tabs and corresponding slots in the corners of the ashtray are used to secure the tray in the assembled position. The cardboard may be coated with a flame-resistant ink. 
     A collapsible lunch bag having snap fasteners for holding the bag in an assembled position is taught by U.S. Pat. No. 2,831,624. The corners of a unitary rectangular blank are creased along diagonals between side and end panels, folded along the creases, and folded over end panels. The end panel has one half of a snap fastener, while one of the folded corners has a corresponding snap and the other corner has apertures for permitting the snap halves to connect. The lunch bag is made of a flexible paperboard or plastic. 
     U.S. Pat. No. 4,790,714 discloses a collapsible toy box which can be made of cardboard or a plastic. The box is made of a single layer only. 
     U.S. Patent Des. 358,936 illustrates the design of an antenna tool kit having a triangular shape with folded over top edges which can be secured to the sides of the kit by snap connectors. The kit has a very sharp triangular shape, with straight sides which are joined together along a majority of the length of their adjacent edges. 
     The prior known collapsible containers primarily rely upon paperboard or pasteboard as the supporting layer for the container. In some cases, the paperboard is coated with a protective layer. None of the prior collapsible containers includes multiple layers of different rigidity but similar thicknesses. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a collapsible container having rigid connected panels which are easily folded and secured in an assembled position. 
     It is a further object of the invention to provide a collapsible container having two different exposed surface layers which may be assembled with either layer on the outside of the container. 
     Accordingly, a collapsible container is provided having a generally planar blank formed from two layers of different materials laminated and sewn together. The two layers are a flexible layer and a rigid or semi-rigid layer. Each blank has a base panel and at least three side panels. Both the blank and the base panel have a general shape with a number of sides corresponding to the number of side panels; that is, a blank with three side panels will have a generally triangular shaped base panel and blank, while a blank with four side panels will have a generally rectangular shaped base panel and blank. 
     The flexible layer of the blank is a single piece which includes each of the side panels and the base panel, so that joints between the adjacent edges of the side panels are formed with the base panel in the flexible layer. The other edges of the side panels are not connected to any other panel. 
     The rigid or semi-rigid layer is not composed of a single, unitary piece, but, rather, separate pieces shaped the same as each side and base panel. The separate rigid pieces are laminated and sewn to the appropriate panel of the flexible layer. 
     A container may be assembled from a blank of the invention by folding the side panels up so that adjacent panel corners overlap each other. The corners are secured to each other. 
     The sides of the containers are not air-tight, but are sufficiently rigid to hold the shape of the container when solid objects are placed in the container. The containers tend to have a rounded appearance resulting from the connection between the sides. The upper and lower edges of the side panels and the edges of the base panel may each be rounded as well, further enhancing the rounded appearance. While it is preferred that the flexible layer is on the inside of the assembled container, due to the rigid layer being discontinuous at the joints, the blanks are reversible. 
     The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the drawings: 
     FIG. 1 is a top plan view of a collapsed tray blank of the invention; 
     FIG. 2 is a bottom plan view of the tray blank of FIG. 1 in the assembled position; 
     FIG. 3A is a side elevational view of an edge of a panel of the blank of FIG. 1; 
     FIG. 3B is a side elevational view of a second embodiment of the panel edge of the blank of FIG. 1; 
     FIG. 4 is a top plan view of another embodiment of a collapsed tray blank according to the invention; 
     FIG. 5 is a bottom plan view of the blank of FIG. 4 in the assembled position; 
     FIG. 6 is a top plan view of a third embodiment of a collapsed tray blank of the invention; and 
     FIG. 7 is a bottom plan view of the blank of FIG. 6 in the assembled position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, in which like reference numerals are used to refer to the same or similar elements, FIG. 1 shows the top layer  60  of a blank  10  for a collapsible tray of the invention. The blank  10  generally triangular shaped and has a base panel  20  which is triangular with convex sides. A crease  25  separates the base panel  20  from each of three connected side panels  30 . 
     Flexible layer  60  is a single integrated piece of material which includes all side panels  30  and base panel  20 . Rigid layer  70 , shown in FIG. 2, by contrast, is formed by individual panels  30   a,    30   b,    30   c  and  20   a  secured to the flexible layer over a corresponding panel  30 ,  20 . 
     The side panels  30  have a generally trapezoidal shape, with convex bases and concave sides and top edges. The concave top edges have the same curvature as the sides of the base panel, as only crease  25  separates them. 
     A fastener  50  is secured to flexible layer  60  adjacent a first base corner  34  of each side panel  30 . A corresponding fastener  52  is secured to rigid layer  70  adjacent a second base corner  32  of the side panels  30   a - 30   c.  The fasteners  50 ,  52  are used to securely hold the blank  10  in its assembled shape while permitting the container to be collapsed again. The fasteners  50 ,  52  are corresponding pieces of a snap fastener in a preferred embodiment, although it is envisioned that other known types of paired fasteners can be used, including hook and loop fasteners. 
     FIG. 2 shows the blank  10  in one assembled position where rigid layer  70  is on the outside of the container. The rigid side panels  30   a - 30   c  are exposed, and their edges form a small gap  27  with the bottom panel  20   a  where they meet, exposing the flexible layer  60 . The narrow gaps  27  between the side panels  30   a,    30   b,    30   c  and the base panel  20   a  in the rigid layer  70  effectively define flexible hinges in the flexible layer  60 . Since the rigid layer  70  does not bend as easily as the flexible layer  60 , the gap  27  is the area of least resistance in the layer  70 , and the unfettered flexible layer  60  is provided with an axis for bending. 
     As seen in the drawing, the blank  10  is assembled into a container by bending side panels  30  of the flexible layer  60  inwardly and overlapping the first and second base corners  34 ,  32  of adjacent side panels  30  so that the fasteners  50 ,  52  are aligned for connecting together. 
     It should be noted that if the fasteners  50 ,  52  are aligned properly, that the blank  10  can be folded backwards and reversibly assembled, with the rigid layer  70  on the inside and the flexible layer  60  on the outside of the assembled container. 
     FIGS. 3A illustrates the two layers  60 ,  70  forming the container blank  10 . As seen in the drawing, the flexible layer  60  is secured to the rigid layer  70  using an adhesive  65  or stitching  75 . When the layers  60 ,  70  are joined using an adhesive, they are preferably laminated to ensure bonding between layers. 
     The layers  60 ,  70  are preferably of similar thicknesses, but their relative thicknesses may vary as well. The flexible layer  60  is {fraction (1/64)} inch up to about ½ inch thick, although greater thicknesses may be possible, and preferably between {fraction (1/64)} inch and ¼ inch thick. The flexible layer is most preferably from {fraction (1/64)} to {fraction (1/16)} inch thick. The rigid layer  70  is {fraction (1/64)} inch or more thick, and preferably between {fraction (1/16)} inch and 1 inch thick. 
     FIG. 3B illustrates a second embodiment in which two rigid layers  70  are joined to a single flexible layer  60 , so that a rigid layer  70  is always exposed. The rigid layers  70  may be laminated to the flexible layer with an adhesive  65 , or stitched as when there is only one rigid layer  70 . 
     In a preferred embodiment, the flexible layer  60  is made from a non-woven material, and most preferably from a felt material. The rigid layer  70  is preferably a stiff leather material. Other materials that can be used for each layer include felt, soft leather, fabric, vinyl, cork and other pliable materials for the flexible layer  60 . The flexible layer  60  must be easily flexible and capable of being laminated and/or sewn and cut using die-cutting machines. Rigid layer  70  can be formed from a variety of materials which are rigid, although a small amount of bending under force is acceptable, including stiff felt, stiff leather, vinyl, wood, cork and plastics. The rigid layer  70  must be able to provide support and structure to the container and be capable of being sewn and cut with a die-cutting machine. 
     FIGS. 4-7 illustrate alternative embodiments for the shape of the container and blank  10 . 
     FIGS. 4 and 5 show a rectangular blank  10  having flexible layer  60  with rectangular base panel  20 , side panels  80  and end panels  85 . The rigid layer  70  is formed by base panel  20   a,  side panels  80   a  and  80   b  and end panels  85   a  and  85   b.  Snap fasteners  50 ,  52  are arranged with one half of each pair at the corners  87  of end panels  85  and the other half at corners  82  of the side panels  80 . This arrangement of fasteners  50 ,  52  results in the container being assembled by having end panel corners  87  overlap both side panel corners  82  at each end of the assembled container. The blank  10  can be assembled inverted as with the triangular blank  10  of FIGS. 1 and 2, by folding the rigid layer panels  80   a,    80   b,    85   a  and  85   b  toward the base panel  20   a  and fastening the snap fasteners  50 ,  52 . 
     The container blank  10  of FIGS. 6 and 7 is for making a square container. The blank  10  has unitary flexible layer  60  forming square base panel  20  and four side panels  90 , delineated by crease  25  between each side panel  90  and the base panel  20 . Snap fasteners  50 ,  52  are provided at corners  92 ,  94  in the same manner as with the embodiment of FIGS. 1 and 2. Rigid layer  70  includes a base panel  20   a  and four side panels  90   a,    90   b,    90   c  and  90   d,  all individually connected to the flexible layer by lamination. 
     The blank  10  of FIGS. 6 and 7 is assembled by overlapping alternating corners  92 ,  94  of adjacent side panels  90  and fastening snaps  50 ,  52  when side panels  90  are folded toward base panel  20 . The blank  10  can be assembled inverted by folding the side panels  90   a,    90   b,    90   c  and  90   d  toward the base panel  20   a  and then fastening fasteners  50 ,  52 . 
     A preferred method for assembling the blanks  10  is to cut the flexible layer  60 , cut rough corresponding rigid layer panels and join them together using lamination. The joined panels  60 ,  70  may then be die cut again as a single blank in order to conform the edges of each panel. The connection of the laminated panels  60 ,  70  can be reinforced by stitching them together after conforming the edges. When the layers are laminated together, the die cut edges may be left raw, as the layers do not separate. 
     While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.