Abstract:
Rugged, soft, interconvertible articles constructed from soft, resilient members, which articles adopt a substantially different geometry upon an interior to exterior interconversion. The articles of the invention provide a significant visual effect and are useful as educational aids, magician&#39;s props, and toys.

Description:
1. FIELD OF THE INVENTION  
         [0001]    The invention is directed to interconvertible articles constructed of soft, resilient material for educational use and amusement.  
         2. BACKGROUND OF THE INVENTION  
         [0002]    Interconvertible toys, which interconvert from one shape to another, promote children&#39;s interest in geometry and provide visual stimulation to children and adults alike. Interconvertible toys that take on a substantially different geometry upon an exterior to interior interconversion, are particularly fascinating. When constructed from soft material, interconvertible toys are advantageous because they are safe for small children and easily manipulated. Many prior-art soft interconvertible toys are not, however, rugged enough to withstand wear associated with repeated interconversion and may deteriorate relatively quickly. Furthermore, such toys are often limited in complexity of movement and visual effect.  
           [0003]    U.S. Pat. No. 5,433,647 (issued Jul. 18, 1995) discloses soft, interconvertible objects made from elastic foam material. The disclosed objects are interconvertible from one geometry to another and constructed from a single piece of material, such as foam.  
           [0004]    Disadvantageously, upon interconversion, stress is concentrated at the interconversion points, which in some designs are hardly wider than a thread. Such stress can cause deterioration and eventual failure of the object. Furthermore, because the object is constructed from a single piece of foam and the inversion focused along a single axis, the variety of visual and mechanical effects is limited.  
           [0005]    U.S. Pat. No. 5,310,378 (issued May 10, 1994) discloses a toy transformable between open and closed conformations. These toys, however, can only nest appendages into matching recesses and, therefore, lack a substantial visual effect. They are not interconverted or inverted.  
           [0006]    U.S. Pat. No. 5,115,528 (issued May 26, 1992) discloses the typical reversible bag- or pillow-type toy where the basic geometry is retained after transformation, but the geometry inside the bag after “stuffing” is greatly distorted. Such as article lacks the same stimulating visual effect obtained upon a true interconversion. In view of the above, there is a need for a rugged, soft interconvertible device that provides a significant visual effect upon interconversion. The discussion of references in this Background Section 2 is provided for background purposes only and no assertion, statement, or admission is made regarding the references&#39; prior art status with respect to the invention.  
         3. SUMMARY OF THE INVENTION  
         [0007]    The invention satisfies the above-mentioned need by providing rugged, soft, interconvertible articles that take on a substantially different, stable geometries upon interconversion, to provide a significant, surprising visual effect. Quite startling effects accompany this interconversion, including exchange of colors and textures and up to tripling the exterior surface area. The articles of the invention are useful as education aids and for amusement, magic tricks, etc. and, thus, provide learning and fun for both children and adults.  
           [0008]    One embodiment the invention is directed to an article comprising a first stable geometry, comprising a plurality of soft, resilient rotatable members, interconnected by hinge-type connections, the members having an interior surface area, wherein the article adopts a second stable geometry upon interconverting one or more of the members. In another embodiment, the invention is directed to a method of interconverting an article from a first stable geometry to a second stable geometry comprising interconverting two or more of a plurality of soft, resilient rotatable members, interconnected by hinge-type connections. 
       
    
    
     4. BRIEF DESCRIPTION OF THE FIGURES  
       [0009]    These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings where:  
         [0010]    [0010]FIG. 1A is a perspective view of an article of the invention having a cube geometry that can be interconverted to an article of the invention having a stellated-cube geometry;  
         [0011]    [0011]FIG. 1B is a perspective view of the article of the invention shown in FIG. 1A illustrating the initiation of interconversion into an article of the invention having a stellated-cube geometry;  
         [0012]    [0012]FIG. 1C is a perspective view of an article of the invention having a stellated-cube geometry that can be interconverted to an article of the invention having a cube geometry;  
         [0013]    [0013]FIG. 2A is an exploded view of the article of the invention shown in FIG. 1A;  
         [0014]    [0014]FIG. 2B is an exploded view of the article of the invention shown in FIG. 1C;  
         [0015]    [0015]FIG. 3A is a perspective view of an article of the invention having a building-shaped geometry that can be interconverted to an article of the invention having a car-shaped geometry;  
         [0016]    [0016]FIG. 3B is a perspective view of the article of the invention shown in FIG. 3A illustrating the initiation of interconversion into an article of the invention having a car-shaped geometry;  
         [0017]    [0017]FIG. 3C is a perspective view of an article of the invention having a car-shaped geometry that can be interconverted to an article of the invention having a building-shaped geometry;  
         [0018]    [0018]FIG. 4 is an exploded view of the article of the invention shown in FIG. 3C;  
         [0019]    [0019]FIG. 5A is a perspective view of an article of the invention having a disk-shaped geometry that can be interconverted to an article of the invention having a sun-shaped geometry;  
         [0020]    [0020]FIG. 5B is a perspective view of the article of the invention shown in FIG. 5A illustrating the initiation of interconversion into an article of the invention having a sun-shaped geometry;  
         [0021]    [0021]FIG. 5C is a perspective view of an article of the invention having a sun-shaped geometry that can be interconverted to an article of the invention having a disk-shaped geometry;  
         [0022]    [0022]FIG. 6 is an exploded view of the article of the invention shown in FIG. 5A;  
         [0023]    [0023]FIG. 7A is a perspective view of an article of the invention having a icosahedron geometry that can be interconverted to an article of the invention having a stellated-icosahedron geometry;  
         [0024]    [0024]FIG. 7B is a perspective view of the article of the invention shown in FIG. 7A illustrating the initiation of interconversion into an article of the invention having a stellated-icosahedron geometry;  
         [0025]    [0025]FIG. 7C is a perspective view of an article of the invention having a stellated-icosahedron geometry that can be interconverted to an article of the invention having a icosahedron geometry; and  
         [0026]    [0026]FIG. 8 is an exploded view of the article of the invention shown in FIG. 7C.  
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0027]    In one embodiment, the invention provides an article comprising a first stable geometry, comprising a plurality of soft, resilient rotatable members, interconnected by hinge-type connections, the members having an interior surface area, wherein the article adopts a second stable geometry upon interconverting one or more of the members. In another embodiment the invention is directed to a method of interconverting an article from a first stable geometry to a second stable geometry comprising interconverting two or more of a plurality of soft, resilient rotatable members, interconnected by hinge-type connections. In preferred embodiments the first stable geometry can be a cube, building shaped, a disk, or icosahedron; the second stable geometry can be a stellated cube, car shaped, sun shaped, or a stellated icosahedron.  
         [0028]    As used herein, the phrase “hinge-type connection” means any type of flexible connection interconnecting members at their edges. The only requirement is that the connection allow for hinge-type movement of the member, and that the hinge itself can be bent during the transition, but recovers elastically from that distortion. Examples of hinge-type connections suitable for use in the invention include, but are not limited to, stitches, staples, or pins joining fabric strips, VELCRO, zippers, rings, or fabric encompassing two or more members, the fabric having a dividing seam between the members. Preferably, the hinges are formed via a soft fabric layer encompassing two or more members, the fabric layer having stitched dividing seams between the members. In other words, the soft members are interrelated through a fabric covering and the hinge-type connections comprise intersection of the fabric covering. Any type of fabric may be used, and will be chosen based on desired qualities of the interconvertible articles of the invention.  
         [0029]    As used herein, the term “member” means any object, of any shape, and of any material, wherein the member is part of an interconvertible article of the invention. A “rotatable member” means a member designed to be turned, rotated, or twisted via a hinge-type connection concomitantly with one or more other rotatable members thereby effecting interconversion of an article of the invention.  
         [0030]    As used herein, the phrase “soft, resilient member” means any object of any shape made from any soft, resilient material, wherein the member is part of an interconvertible article of the invention. “Soft” means that the member is readily deformable on touch; for reference purposes, examples of soft objects are pillows, air-filled balloons, foam rubber, etc. “Resilient” means that the member assumes its original shape once the stress that induced distortion is removed. Preferably, a resilient member is compressible to the extent of from about 50% to about 90% of its volume and, upon release of the compressive force, assumes its original shape in about one to three seconds. Suitable soft, resilient materials for use in the invention include, but are not limited to, foamed plastics such as latex or urethane open-cell foams, air-filled elastic latex balloons, or fabric bags filled with spun stuffing, made for example from cotton, goose down, or nylon. Preferably, the soft, resilient members are covered with colorful or otherwise appealing fabric. These fabrics can be slightly elastic (by co-weaving with rubber), metallized, made from “fake fir”, or tough rip-stop nylon normally used in backpacks.  
         [0031]    As used herein, a “stable geometry” means that the article of the invention is in a definite shape that is rigid to the extent that it is not floppy, limp, sagging, or droopy and expands back to the original definite shape if compressed or otherwise deformed, such as may occur during rough play.  
         [0032]    The phrase “interior surface area” with respect to a soft, resilient members in an  1 - 5  article of the invention in a particular stable geometry, means that portion of the member&#39;s surface area that is not visible because it is enclosed or shielded from sight within the article. For example, with respect to FIG. 1B (discussed in more detail below), the interior surface area of member  2   a  of article  1  in conformation  1   a , consists of the surface area of the four triangular faces  8 . The exterior surface of an article means the visible surface area not enclosed within the article.  
         [0033]    As used herein, the phrase “interconvertible interior surface area” with respect to an article of the invention means that portion of the member-defined interior surface area that is exchanged to the articles exterior surface upon interconversion. See for example FIG. 2B, discussed in more detail below, where the sum total surface area of bases  10  define the interconvertible interior surface area if article  1  in geometry  1   b.    
         [0034]    As used herein, the term “interconversion” or “interconverting” with respect to a rotatable member means moving or rotating the member such that there results an exchange of a portion of the member&#39;s interior surface area to the exterior surface.  
         [0035]    As used herein, the term “interconversion” or “interconverting” with respect to an article of the invention means turning, rotating, or twisting one or more of the rotatable members such that there results an exchange of the article&#39;s interconvertible interior surface area to the exterior surface. See for example, FIGS.  1 A- 1 C, discussed in more detail below, wherein article  1  in geometry  1   a  is interconverted to geometry  1   b  by interconverting rotatable members  2 . Preferably, upon interconversion, an article of the invention converts from a first stable geometry to a second stable geometry. It is also preferable that upon interconversion that the members maintain their original shape in the second stable geometry that they had in the first stable geometry. Thus, while deformation of the members occurs during interconversion, the individual members, due to their resiliency assume their original shape in the second stable geometry.  
         [0036]    A few embodiments of interconvertible articles of the invention are illustrated in FIGS.  1 - 8 . In general, the interconvertible articles of the invention comprise a plurality of soft, resilient members that are interconnected at specific edges by hinge-type connections. Certain of the soft, resilient members are designed to be rotated 180 degrees (“rotatable members”). These rotatable members define an interior surface (“interconverting interior surface”). When the rotatable members are concomitantly rotated 180 degrees, the article interconverts such that the interconverting interior surface becomes the exterior surface (“interconverting exterior surface”). Because the interconverting interior and exterior surfaces can be designed such that they have substantially different geometries, colors, and textures, an exciting visual effect accompanies interconversion. To allow room for interconversion, certain soft, resilient members are unconnected at particular edges. Such unconnected edges define an “interconversion opening”. Pulling the soft, resilient members at the interconversion opening initiates interconversion, whereby a first stable geometry “snaps” to a second stable geometry. The snapping effect results from the potential energy generated by member distortion during interconversion. When the soft, resilient members are distorted, the potential energy generated tends to impel them back to their original shape. They can achieve their original shape by assuming a position consistent with either the article&#39;s first or second geometry. Beyond a “transition point” the article&#39;s second geometry is favored and the potential energy of distortion is released as the soft, resilient member assumes the second position consistent with the article&#39;s second geometry. After each rotating member assumes the second position, the interconversion is complete, and the resilient members return to their undistorted shapes.  
         [0037]    One of skill in the art, by reference to the drawings and description herein, can design a wide variety of interconvertible articles of the invention by providing a shell of soft, resilient material having exterior and interior surfaces of desired design; dividing the shell into soft, resilient members; and interconnecting the soft, resilient members with hinge-type connections such that appropriate soft, resilient members can be concomitantly rotated 180 degrees. Typically, one begins by considering the most compact state (e.g. a solid cube) and then divides the solid body into a multitude of elements (e.g. pyramids) with common edges on the hinge lines. The larger the apparent volume and shape change, the more fascinating the transition.  
         [0038]    FIGS.  1 A-LC illustrate an article of the invention  1 , which can be interconverted from stable cube geometry  1   a  (FIG. 1A) to stable faceted-ball geometry  1   b  (FIG. 1C). As shown in the exploded view of faceted-ball geometry  1   b  (FIG. 2B), article  1  is constructed of six pyramidal-shaped soft, resilient members  2 . As shown in FIG. 2B, faceted-ball geometry  1   b  defines cube-shaped interior volume  3 . Referring to FIG. 2B, the six members  2  are interconnected at edges  4  via hinge-type connections  5 . For simplicity, only one hinge-type connection  5  is shown in the drawing; however, edges  4  having hinge-type connections  5  are designated as broken lines in FIG. 2. All of the six members  2  are hinged at each of their four edges  4  (some hinged edges are not shown due to the limitations of the perspective drawing) except for member  2   a , which, is hinged on just two of its four edges (see FIG. 2B, there are no hinge-type connections at edges  4   a  and  4   b  as indicated by the use of solid rather than hinge-indicating broken lines), thereby defining interconversion opening  7  (FIG. 1B). Article  1  is interconverted from cube geometry  1   a  to faceted-ball geometry  1   b , having twenty four triangular faces  8 , by rotation of each of the six members  2  via the hinge-type connections  5 . Mathematicians refer to geometry  1   b  as a stellated cube. Interconversion is accomplished, as illustrated in FIG. 1B, by pulling member  2   a  outward and concomitantly pushing corner  9  upward. Note that the members  2  are the same pyramidal shape in both geometries  1   a  and  1   b . In geometry  1   b , the pyramidal bases  10  face inward defining an interconvertible interior surface area (i.e., the sum surface area of the six bases  10 ). This interconverting interior surface defines interior volume  3 , which is a hollow space of about the same volume as the first geometry  1   a . Upon interconversion to faceted ball  1   b , the outer dimension of the interconvertible cube  1   a  roughly doubles. When the bases  10  of the pyramidal members  2  are colored red, while the triangular sides are colored blue and made of artificial fur, the rapid switch in shape, size, color, and texture upon interconversion is both astonishing and entertaining. The article is useful as a toy, magician&#39;s prop, educational aid, ball, and even as a storage container, due to its high mechanical stiffness in either geometry.  
         [0039]    FIGS.  3 A- 3 C illustrate another embodiment of the invention, article  10 , which can be interconverted from stable building geometry  10   a  to stable car geometry  10   b . As shown in FIG. 4&#39;s exploded view of car-geometry  10   b , article  10  is constructed from the five soft, resilient members  11  ( 11   a ,  11   b ,  11   c ,  11   d , and  11   e ). Hinge-type connections  12  at interconnecting edges  13  interconnect the five members  11 . In FIG. 4, broken lines indicate edges  13  that are interconnected by hinge-type connections  12 , while solid lines indicate edges  13  that are not interconnected. The appropriate edges are unconnected to define interconversion opening  14  (FIGS. 3A and 3B). Note that due to the perspectives limitations, some edges  13  are not shown. Article  10  is interconverted from building geometry  10   a  to car geometry  10   b  by rotating members  11   a ,  11   b , lic, and  11   e  via the hinge-type connections  12 . Initiation of this interconversion is illustrated in FIG. 3B where the arrows indicate the direction of member rotation. As shown in FIG. 3B, the user may interconvert article  11  by pulling members ha and  11   e  outward and concomitantly pushing down on member  11   d.    
         [0040]    Article  10  can be decorated as desired, for example, with decorative wheels  15 . Both of geometries  10   a  and  10   b  are quite stiff and stable and suited for robust play. Indeed, the stability makes the interconversion surprising.  
         [0041]    FIGS.  5 A- 5 C and  6  illustrate a third embodiment of the invention, article  20 , which can be interconverted from stable disk geometry  20   a  to stable sun geometry  20   b . As shown in the exploded view of FIG. 6, article  20  is constructed from the ten soft, resilient falcate-shaped members  21 , circular fabric band  22 , and disk-shaped member  23 . As shown in FIG. 6, in conformation  20   a , the four back edges  24  of each of soft, resilient members  21  are adjacent to the inside of circular fabric band  22 , which in turn is attached to disk-shaped member  23  via hinge-type connection  25 . Article  20  is interconverted from disk geometry  20   a  to sun geometry  20   b  by rotation of each of members  21  via hinge-type connection  25 , whereupon, circular fabric strip  22  folds over and contacts the outer circumference  26  of disk-shaped member  23 . As illustrated in FIG. 5B, this is accomplished by pulling members  21  upward and over via interconversion opening  27 .  
         [0042]    FIGS.  7 A- 7 C and  8  illustrate an article of the invention  30 , which can be interconverted from stable icosahedron geometry  30   a  (FIG. 7A) to stable stellated icosahedron geometry  30   b  (FIG. 7C). As shown in the exploded view of stellated icosahedron geometry  30   b  (FIG. 8), article  30  is constructed of twenty triangular-based pyramid-shaped soft, resilient members  31  and, in stellated icosahedron geometry  30   b , defines icosahedron-shaped interior volume  32 . The twenty members  31  are interconnected at the edges of their triangular bases  33  via hinge-type connections  34 . For simplicity, only one hinge-type connection is shown in the drawing, however, edges  33  having hinge-type connections  34  are designated as broken lines in FIG. 8. All of the twenty members  31  are hinged at each of their three triangular base edges  33  (some hinged edges are not shown due to the limitations of the perspective drawing) except for adjacent members  31   a  and  31   b  (see FIGS. 7A and 7B), which, are hinged on just one of their respective edges  33  thereby defining interconversion opening  36  (FIG. 7B). Interconversion opening  36  is sufficient to allow interconversion and does not compromise stability of either geometry  30   a  or  30   b . Article  30  is interconverted from icosahedron geometry  30   a  to stellated icosahedron geometry  30   b , having twenty-four triangular faces  35  (FIG. 7B), by rotation of each of the twenty members  31  via the hinge-type connections  35 . Interconversion is accomplished, as illustrated in FIG. 1B, by pulling members  31   a  and  31   b  of interconversion opening  36  outward and concomitantly pushing the opposite corner upward. Note that the members  31  are in the same triangular-based pyramidal shape in both geometries  30   a  and  30   b . In geometry  30   b , the triangular bases  35  face inward defining an interconvertible interior surface area. This interconverting interior surface defines volume  32 , which is a hollow space of about the same volume as the first geometry  30   a . Upon interconversion of  30   a  to  30   b , the outer dimension of article  30  roughly doubles. Stunning effects can be achieved by color and texture differences between the triangular sides and bases.  
         [0043]    The articles of the invention may be decorated in any manner, for example, in article  10 , car windows, wheels  15 , etc. can be added to the car surface, while windows, doors, etc. can be added to the building surface.  
         [0044]    The foregoing description of non-limiting embodiments of the invention has been presented for illustrative purposes. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and many modifications and variations are possible in light of the above teachings without deviating from the spirit and the scope of the invention. The embodiments described are selected to illustrate the principles of the invention and its practical application to thereby enable others skilled in the art to practice the invention in various embodiments and with various modifications as suited to their particular purpose.