Abstract:
A structure is described that has an open and closed configuration. In the open configuration, the structure is free standing and is able to support weight. In the closed configuration, the structure is flat. The structure is formed of two elements that are interlocked at their corners in a manner that allows them to pivot with respect to each other. Chamfered surfaces on the sides of the elements provide stops limiting the motion between the elements. Several structures may be combined to form composite products.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority to provisional application Ser. No. 60/840,621 filed Aug. 28, 2007 and incorporated herein by reference. 
     
     BACKGROUND OF THE INVENTION 
       [0002]    A. Field of Invention 
         [0003]    This invention pertains to a support or frame structure made of at least identical elements, each element having the shape of a parallelogram, the two elements being joined together in a manner that permits some pivoting of the elements about a diagonal axis. 
         [0004]    B. Description of the Prior Art 
         [0005]    A basic structural element used for many different purposes is a truss. A typical truss is formed of three linear rigid members, such as bars joined at their ends to form a triangle. Several trusses can be interconnected to form more complex three-dimensional support members. Trusses have been found to be very desirable structural elements because they can withstand large static and dynamic stresses and compressions without damage and are used in many different situations and common every-day objects, starting from relatively small objects such as small picture frames and stands, saw horses, and going all the way to large bridges and building sections. 
         [0006]    In some situations support structures are required that can be folded for storage or shipping. For these situations, structures are used that include one or more joints that are either disassembled, or provided with hinges. However, these structures are generally expensive, less reliable, and, often, esthetically unacceptable. 
       SUMMARY OF THE INVENTION 
       [0007]    A basic support structure or frame constructed in accordance with this invention includes two elements, generally having the shape of a parallelogram with two opposed corners defining a diagonal axis. The two elements are interlocked at the two opposed corners in a manner that allows them to pivot with respect to each other around said diagonal axis. Preferably the elements have sides that are chamfered at least at said corners to provide a stop limiting the respective pivoting of the two elements. In this manner the structure is formed without any hinges or other similar means between the two elements. 
         [0008]    In one embodiment, each element is formed of two joined L-shaped components. In one embodiment, the components of the two elements are identical. 
         [0009]    The structure is used to make or support various products. For some of these applications, the structures are formed of square or rectangular elements. In other applications the elements have obtuse and acute rather then right angles. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIGS. 1A and 1B  show a front and a back view of a component for a first embodiment of the invention; 
           [0011]      FIGS. 2A ,  2 B and  2 C show two components like the ones shown in  FIGS. 1A ,  1 B being joined to make a first element; 
           [0012]      FIGS. 3A and 3B  show two elements similar to the ones shown in  FIGS. 2A and 2B  joined to make a basic folding support; 
           [0013]      FIG. 3C  shows a side view of the support; 
           [0014]      FIG. 3D  shows an isometric view of the support formed in  FIGS. 3A and 3B , with the two elements being rotated about axis L-L; 
           [0015]      FIGS. 4A and 4B  show the components of an alternate embodiment of the invention; 
           [0016]      FIG. 5  shows an isometric view of a square saw horse constructed in accordance with this invention; 
           [0017]      FIGS. 6A and 6B  show isometric views of a table with one and two support structures, respectively; 
           [0018]      FIGS. 7A and 7B  show a blown up view and an isometric view, respectively, of a picture frame constructed in accordance with this invention; and 
           [0019]      FIG. 8A  shows a plan view of an element for a more complex structure; and 
           [0020]      FIG. 8B  shows an isometric view of a bottle holder using the element from  FIG. 8A . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0021]    In one embodiment of the invention, a structure constructed in accordance with a first embodiment of the invention is formed of four identical components.  FIGS. 1A and 1B  show the front and back of such a basic component  10 . The component  10  is generally L-shaped with a first leg  12  and a second leg  14 . In the following embodiments the two legs are shown perpendicular to each other, however, they may be at an acute or obtuse angle as well, as described below. Preferably, the two legs have the same width X. 
         [0022]    Leg  12  has a length Z and is chamfered at its free end as shown at  18 . Leg  14  has a length Y and is formed with a cut-out  16  at one end with chamfered or beveled surfaces as at  20 . The chamfer angle can range from 10 to 80 degrees, this angle being different for different sizes and applications, as discussed below. 
         [0023]    Referring to  FIGS. 2A-2C , two components  10 A,  10 B are then joined to form a first element  22 A as follows: starting with  FIG. 2A , first component  10 A is positioned as shown, and the second component  10 B is rotated to the position shown with respect to component  10 A. The two components  10 A,  10 B are then partially superimposed at the two opposite ends and joined to form a first element  22 A. The components  10 A,  10 B can be joined by any well known means. For example, an adhesive may be applied between them. Alternatively, the two components may be screwed, nailed or welded together. 
         [0024]    The resulting element  22 A is shown in a plan view in  FIG. 2C . In this figure the chamfered surfaces have been omitted for the sake of clarity. As can be seen in this figure, the element  22 A has a rectangular shape having a width of Z+X/2 and a height of Y. If the legs are identical the element  22 A is a square. The two components  10 A,  10 B overlap at two diagonally opposite corners  24 ,  26 . More specifically, at corner  24 , the components form an overlapping inner square region  24 A and an outer square opening  24 B. At corner  26 , the components  10 A,  10 B form an inner square opening  26 A, and an outer square region  26 B. The components are joined in regions  24 A,  26 B and common regions  24 A,  26 B. Openings  26 A,  24 B all have a square shape with an X/2 side. These features are disposed symmetrically about a diagonal axis L-L. 
         [0025]    Referring now to  FIGS. 3A ,  3 B,  3 C,  3 D, a second element  22 B is provided that is identical with the element  22 A and is formed of components  10 C,  10 D. The second element  22 B is assembled from its components  10 C,  10 D so that it is interlocked with element  22 A. More specifically, first the component  10 D is disposed under component  10 B as shown in  FIG. 3A . The component  10 D is positioned with its common regions used for joining it to the component  10 C are visible through the openings  26 A,  24 B. Then component  10 C is placed over component  10 A and joined to component  10 D through openings  26 A,  24 B using an adhesive, for example. Thus, it should be apparent that second element  22 B is rotated by 180 degrees with respect to element  22 A. It should be further apparent that the two elements  22 A,  22 B are interlocked because the common regions of one are disposed in the windows of the other, and vice versa. It should be appreciated that the overall thickness of structure  30  is equal to double the thickness of any of the components  10 A,  10 B,  10 C,  10 D, as shown in  FIG. 3C . 
         [0026]    Since the two elements  22 A,  22 B are not mechanically fixed to each other, they can pivot with respect to each other along diagonal axis L-L as shown in  FIG. 3D . Importantly, the movement of the elements is limited by the chamfered surfaces  18 ,  20 . In other words, the two elements  22 A,  22 B can be pivoted from the superimposed or closed configuration shown in  FIG. 3B  toward the open configuration shown in  FIG. 3D  until the chamfered surfaces of the components come into contact with each other. The two elements  22 A,  22 B cannot be pivoted any further because the chamfered surfaces act as stops and will resist any additional forces to pivot them further. In this manner, structure  30  in the open configuration is a free standing structure that can rest on a surface on its own and can be used to support additional weight, as discussed in detail below. 
         [0027]    While elements  22 A,  22 B are each made of two components, it should be understood that they may be made of a single component as well, using standard techniques dependent on the material of the component. For example, the elements are best made from two components if they are made of paper or cardboard. If the elements are made of metal, wood, plastic, etc., they can be made from a single component, by casting molding, etc. If they are made of a single component, however, during assembly at least, one of the elements will have to be cut or other means must be provided so as to allow the two elements to be assembled in the interlocking position required to make the structure  30 . 
         [0028]    In the embodiment described so far, the components are provided with chamfered surfaces only at the corners where the elements are interlocked. In an alternate embodiment, some or all the edges of the components are chamfered or beveled for esthetic reasons, as shown in  FIG. 3C  in order to provide better support surfaces for objects disposed on the structure  30  and so on or for esthetic reasons. 
         [0029]    In the embodiment of  FIGS. 1 ,  2 , and  3 , the elements  22 A,  22 B are made of all identical components. In an alternate embodiment shown in  FIGS. 4A and 4B , a first element  41  is made of two components, such as component  40 A. Component  40 A has cutouts  42  with chamfered surfaces (not shown) at both ends. The two components  40 A,  40 B are joined at two outer regions  42 A,  44 A and form two inner openings  42 B,  44 B ( FIG. 4A ). The other element is assembled from two identical components, with only component  46 A being shown in  FIG. 4B  (component  40 B being shown only in phantom lines for the sake of clarity). The ends of component  46 A do not have cutouts. The components of the second element are joined together at common regions  48 A,  50 A through openings  42 B,  44 B. Component  46 A has a height and length that is X/2 shorter than components  42 A,  42 B. The resulting structure formed from interlocking these elements functions in the same manner as the one shown in  FIGS. 1-3 . 
         [0030]    As noted, the structures of  FIGS. 1-4  can be used either as free standing structures or as structures supporting various other objects. More specifically, by properly sizing, shaping, and selecting the appropriate materials, (and by adding additional parts, as required) the structures can be used to make picture frames, saw horses, table legs, architectural rulers, floor lamps, table lamps, mirrors, wine racks, bookshelves, divider walls, window systems, prefabricated enclosures, and many other similar products. Some of the products are shown in the Figures. In some of these products, the structure may be made of components that do not have a uniform thickness. In some of the structures, one or both elements are not square or rectangular, but instead have a general rhomboid shape (or the shape of a parallelogram) in which the elements have obtuse and acute rather then right angles. 
         [0031]      FIG. 5  shows a square saw horse made of stained and finished hardwood, lacquered or stained and finished MDF (medium density fiberboard), etc. The edges are chamfered at an angle of about 80 degrees and the components are joined by screws passing through holes drilled at about 76 degrees. 
         [0032]      FIGS. 6A and 6B  show a table with one and two supports, respectively, the supports being structures constructed in accordance with the invention. In  FIG. 6A , two square elements are used with 50 degree chamfer surfaces. 
         [0033]      FIG. 7A  shows one element  50  of a picture frame  51  in which L-shaped components  50 A,  50 B (made of plastic, metal, etc) form a frame for a transparent cover  52 , a picture  54  and a back  56 . The second element  58  is provided to interlock with element  50  and form the frame as shown in  FIG. 7B . 
         [0034]    Of course the concepts described above can be extended to form supports having several elements. For example, an element having a zig-zag shape is shown in  FIG. 8A . The element  60  is formed of several legs  62  disposed normal to each other. At each corner, cutouts  64  are provided for making regions and openings as described above. Moreover, in some instances, several cutouts may be provided at each corner to provide a more robust interlock at each corner between the elements.  FIG. 8B  shows a bottle holder made of several elements  60  that interlock as described above. 
         [0035]    Numerous modifications may be made to the invention without departing from its scope as defined in the appended claims. For example, a structure can be made of L-shaped elements where the legs of the L pieces have different widths. In this embodiment the structure does not include four identical elements but in two sets of identical elements. In this embodiment, the shape of the common region and the opening at the corners are rectangular rather that square. Moreover, as mentioned above, the L shaped pieces need not meet at a right angle, resulting in a structure in which the common regions and the openings at the corners are parallelograms having obtuse and acute angles rather then being square or rectangular. These changes in dimension and shape of the L pieces of the structure may change the shape of the common region and the opening at the corners without departing from the scope of the invention defined in the appended claims.