Abstract:
The present invention discloses a spherical puzzle whose visible segments are delimited by seven planar sections through the center of said sphere and may be permuted by rotations of hemispherical groups of visible segments with respect to any planar section of the puzzle about an axis perpendicular to said section through the center of said sphere. Three planar sections are parallel to the faces of a cube inscribed in said sphere, and the remaining planar sections are perpendicular to the diagonals of said cube. The visible segments comprise eight arcuate equilateral triangles and twenty-four arcuate right triangular triangles. As a novelty, this invention integrates an interlocking mechanism of the arcuate right triangular outer segments to a spherical center support with four axes of rotation, with a slidable spring activated interlocking mechanism of the arcuate equilateral triangular outer segments to their side neighbors.

Description:
[0001]    I hereby claim the benefit of the filing date of a copending Provisional Utility Patent Application, with Application Number 61765053, entitled “Three-dimensional Puzzle with Seven Axes of Rotation”, filed on Feb. 15, 2013. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to three-dimensional logical puzzles which include a plurality of segments interlocked in a spherical shape, the segments being capable of adopting a plurality of positions relative to one another by a sequence of rotations of hemispherical groups of segments. 
       DESCRIPTION OF THE RELATED ART 
       [0003]    The art of three-dimensional logical puzzles that comprise a plurality of interconnected segments to be unscrambled by rotating some of the segments relative to each other sequentially along planes in space, gained popularity with the advent of Rubik&#39;s 3-D twisty puzzles in the early 1980s, including the Cube, Snake, and Pyramid. Since then, several similar puzzles have been invented giving birth to a brand new toy industry and initiating the study of their properties and solving complexity. The rotation of individual pieces or groups of pieces provides a great number of possible combinations of the individual pieces only one or a few of which are solutions. The solutions are pattern or color combinations selected by the creator or manufacturer from all the other possible combinations of the pieces. 
         [0004]    Of particular interest are the puzzles comprising segments coupled together to form a spherical shape, and which always involves the relative rotation of two complete half spheres. These inventions are interesting both as standalone embodiments and as parts of more complex mechanisms. The complexity of these puzzles can be appreciated by looking at the number and orientation of their axes of rotation, and at the means to keep the segments interlocked. 
         [0005]    One way to interlock the elements comprising the puzzle is by means of a spherical central structure with circular tracks receiving legs and feet of slidable outer segments. The proper alignment of the outer segments with said central part is ensured by fastening one of the outer segments to the central part. Inventions of this kind are disclosed in U.S. Pat. No. 213,030 (T. Isobe) and U.S. Pat. No. 4,478,418 (B. F. Sherman Jr. and S. Francis), which enable the embodiment of a puzzle comprised of eight blocks installed around a central part such that four blocks at a time can be rotated by multiples of 90° about any of three orthogonal axes. 
         [0006]    U.S. Pat. No. 4,441,715 (S. C. Titus) discloses another interlocking approach, by means of slidably interlocking connections—arcuate T-shaped slots and complementary arcuate T-shaped studs—between the pieces such that any two interlocked hemispheres can be rotated by 180° relative to each other. The preferred embodiment of this prior invention is a hollow sphere whose outer segments are delimited by planar sections of said sphere having in common a line joining two diametrically opposite poles of the sphere, and can be subjected to rotations by 180° of differing pairs of hemispheres along said planar sections. 
         [0007]    U.S. Pat. No. 5,358,247 (U. Meffert and A. L. Chau) discloses yet another interlocking approach, based on an armed spider whose rotatable tips are the fixed segments of said puzzle. The other segments of the puzzle are coupled with the fixed segments in a spherical shape, and can be permuted by multiple of 120° rotations of hemispherical groups of said segments along planes perpendicular to the four branches of the spider. 
         [0008]    U.S. Pat. No. 4,474,377 (J. J. Ashley) discloses a cubical puzzle whose twenty-four exposed pieces may be permuted by rotations of groups of said pieces about any of seven axes passing through the vertices and the centers of the faces of said cube. Unfortunately, this invention is neither intended nor adaptable for puzzles with rotations of hemispherical groups of segments. 
         [0009]    What is desired, and not heretofore been developed, is a spherical puzzle with thirty-two exposed segments which may be permuted by rotations of hemispherical groups of said segments about seven axes passing through the center of said sphere. The easiest way to visualize the relative positions of these axes is by drawing a cube whose center coincides with the center of the spherical puzzle: three axes cross the center of the cube and are perpendicular on its faces, whereas the other four axes of rotation are determined by the center and a corner of the cube. 
       SUMMARY OF THE INVENTION 
       [0010]    It is an object of the present invention to provide a puzzle in the shape of a sphere with seven axes of rotation and with increased entertainment value. The puzzle has thirty-two visible segments delimited by seven planar sections through the center of said sphere, which may be permuted by rotations along any said planar section. Three sections are parallel to the faces of a cube inscribed in said sphere, therefore the axes of rotation perpendicular to them will be called cubical axes. The remaining four sections are perpendicular to the diagonals of said cube, therefore the axes of rotation perpendicular to them will pass through the vertices of a regular tetrahedron inscribed in said sphere and will be called tetrahedral axes. There are eight visible segments with arcuate equilateral triangular faces and twenty-four visible segments with arcuate right isosceles triangular faces, forming fourteen different hemispherical groups rotatable relative to each other about said axes. The cubical axes are intended for hemispherical rotations of the segments of the puzzle by integer multiples of 90°, and the tetrahedral axes are intended for hemispherical rotations by integer multiples of 120°. 
         [0011]    The preferred embodiment of this invention comprises a spherical center support and a plurality of thirty-two outer segments of uniform thickness which enclose completely the spherical center support. The spherical center support is an embodiment of the spherical puzzle disclosed in U.S. Pat. No. 5,358,247 (U. Meffert and A. L. Chau), modified to include three orthogonal crossing tracks wherein each track forms a complete circle in the support along the diagonals of the arcuate square puzzle segments of said center support, and includes a pair of outer lips extending toward each other to define a narrow outer slot and an inner enlarged sliding path. The said plurality of thirty-two outer segments comprises:
       eight segments of arcuate equilateral triangular shape and twenty-four segments of arcuate isosceles right triangular shape, wherein every arcuate segment of equilateral triangular shape abuts three said segments of arcuate right triangular shape,   legs mounted on said outer segments of arcuate right triangular shape and extending through the narrow slot of said crossing tracks of said spherical center support,   feet mounted on the inner ends of said legs for sliding in the inner enlarged paths of said crossing tracks and for being engaged by inner surfaces of the lips of said crossing tracks to retain said right triangular outer segments on said spherical center support,   one outer arcuate equilateral segment called anchor, fastened on top of an arcuate equilateral triangular segment of the spherical center support,   U-shaped slots along all sides of arcuate outer segments adjacent to the section planes perpendicular to the tetrahedral axes of the puzzle,   spring latching mechanisms mounted on each side of the arcuate outer segments of equilateral triangular shape, comprising a tongue which is urged by a spring to protrude from its segment into the U-shaped slot facing them on the abutting outer segment.
 
The spring latching mechanisms keep the outer equilateral segments in position between the abutting outer segments of the puzzle, and provides a slidable interlocking connection for them. The anchor ensures the alignment of the outer segments with the segments of the center support.
       
 
         [0018]    As a logical puzzle, this invention is also provided with some easily recognizable coloring or pattern on the visible faces of the outer segments, such as the assignment of a distinct color to every octant of the sphere comprising one equilateral and three right triangular segments. The puzzle may be scrambled by a series of rotations by integer multiples of 90° about cubical axes and integer multiples of 120° about tetrahedral axes. The object of the puzzle is to return by means of a series of such rotations to the unscrambled coloring or pattern. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a perspective view of a preferred embodiment of this invention. 
           [0020]      FIG. 2  shows two views of this invention subjected to rotations. The left view shows a rotation about a cubical axis, and the right view shows a rotation about a tetrahedral axis. 
           [0021]      FIG. 3  is a perspective view of the spherical central support of this invention. 
           [0022]      FIG. 4  is perspective view of a typical prior art embodiment disclosed in U.S. Pat. No. 5,358,247 (U. Meffert and A. L. Chau). 
           [0023]      FIG. 5  is an exploded view of the portion of this invention comprising an arcuate square segment of the spherical central support and four right triangular external segments mounted on top of it. 
           [0024]      FIG. 6  is a partial section view of this invention with a plane through the center of the puzzle perpendicular to a cubical axis. 
           [0025]      FIG. 7  is a is a detailed view of a portion of the spherical central support with legs and feet of arcuate right triangular members of the puzzle shown at a junction of tracks. 
           [0026]      FIG. 8  is a perspective view of this invention with the outer equilateral triangular segments of the puzzle exploded outward a common distance from their installed positions. 
           [0027]      FIG. 9  is an exploded view of an outer arcuate equilateral segment of this invention. 
           [0028]      FIG. 10  is a median cross section view of an outer equilateral triangular segment of this invention. 
           [0029]      FIG. 11  is a perspective view of this invention which shows the coupling between its components during a rotation about a cubical axis. 
           [0030]      FIG. 12  is a perspective view of this invention which shows the coupling between its components during a rotation about a tetrahedral axis. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0031]    Overview: The present invention is a puzzle in the form of a sphere comprising a spherical central support and a plurality of thirty-two visible segments of uniform thickness which forms an outer shell enclosing completely the said spherical central support.  FIG. 1  is a perspective view of the preferred embodiment of this invention. The visible segments of the puzzle are delimited by seven planar sections through the center of said sphere which produce the great circles  12 ,  13 ,  14 ,  15 ,  16 ,  17 ,  18  on the surface of said sphere. The planar sections containing great circles  13 ,  15 , and  17  are perpendicular to each other. As a result, the plurality of visible segments of the puzzle comprises twenty-four segments  40  with arcuate right isosceles triangular faces, and eight segments  50  with arcuate equilateral triangular faces. The puzzle is constructed in such a way (described below) that any hemispherical groups of outer segments separated by a sectioning plane can be rotated relative to each other along the sectioning plane. In  FIG. 2 , the left view shows a rotation about a cubical axis perpendicular to a plane containing one of the great circles  13 ,  15 , or  17 . The right view of  FIG. 2  shows a rotation about a tetrahedral axis perpendicular to a plane containing one of the great circles  12 ,  14 ,  16 , or  18 . 
         [0032]    Spherical central support: The spherical central support of this invention is an adjustment of an embodiment of the spherical puzzle with four axes of rotation disclosed in U.S. Pat. No. 5,358,247 (U. Meffert and A. L. Chau) and illustrated in  FIG. 4 .  FIG. 3  shows a preferred embodiment of the spherical central support, which comprises six segments  10  and eight segments  20  obtained by adding three mutually orthogonal crossing tracks  32 ,  34  and  36  to the prior art shown in  FIG. 4 , wherein each track has an arcuate T-shaped cross section and follows a great circle along the diagonals of the arcuate square segments of said prior art, by including a pair of outer lips extending toward each other to define a narrow outer slot and an inner enlarged sliding path. 
         [0033]    Outer shell: The twenty-four arcuate right triangular segments of the outer shell are mounted on the crossing tracks of the spherical central support. As shown in  FIG. 5  and  FIG. 6 , each outer segment  40  is provided with a leg  42  mounted on the inside of its right corner and an inwardly projecting foot  44 , dimensioned to have a profile complementary to the profile of the cross section of the crossing tracks, thus being free to slide within and be retained by the crossing tracks via the projecting foot. Also, a group of four outer shell segments  40  positioned at the junction of two crossing tracks is also free to rotate slidably about its axis of symmetry, on top of segment  20  below, as shown in  FIG. 7 . The width of projecting foot  44  is dimensioned to be sufficiently large in comparison to the width of the narrow outer slot of the crossing tracks, to ensure the permanent retainment of segments  40  on the spherical center structure when they are slidably moved along crossing tracks or rotated at a junction of crossing tracks. Thus, outer segments  40  are free to slide along the crossing tracks of the center support and to slidably rotate as groups of four at a junction of crossing tracks on the spherical central support. 
         [0034]      FIG. 8  is a perspective view of this invention with segments  50  exploded outward a constant distance from their installed positions. One segment  50  is fastened on top of an arcuate triangular segment of the central spherical support. The other segments  50  have no connections whatsoever to the spherical central support, but are held in place by the neighboring outer segments. The interlock between segments  50  and their neighbors is based on spring latching mechanisms installed on the sides of segments  50 , with tongues protruding in complementary U-shaped side channels along the adjacent sides of their neighbors.  FIG. 9  is an exploded view of segment  50 . Every spring latching mechanism of segment  50  comprises an arcuate tongue  52  of uniform thickness slidably mounted in a slot on one side of said segment  50 , which is urged by a spring  58  mounted behind said tongue to protrude from said segment  50  in a complementary slot  54  of the outer segment facing said tongue.  FIG. 10  is a median cross section of the preferred embodiment of segment  50 , which shows how a spring mounted in a cylindric slot behind a tongue holds said tongue in a small indentation outside the edge of said segment  50  by applying a tension behind said tongue. The sliding slots of tongues inside segment  50  are shown in  FIG. 9  with phantom lines. 
         [0035]    When protruded, the outer surfaces of tongues are engaged by the inner surfaces of the side tracks of slots  56  and prevent segment  50  comprising said tongues from falling out from the outer shell of the puzzle. There are eight side tracks for the tongues, one side track on each side of the outer shell delimited by a section along the great circles  12 ,  14 ,  16  and  18  shown in  FIG. 1 . Also, during rotations about tetrahedral axes, the protruded tongues are free to slide along said side tracks, and sometimes they collide with protruded tongues of segments  50  on the other side of the separating plane of rotation. When a collision between tongues occurs, the said tongues are pushed in directions opposite to the tension of their springs until they slide into their comprising segments  50  just enough to enable the sliding of said segments  50  beside each other. 
         [0036]    Rotation about cubical axis:  FIG. 11  is a perspective view of the puzzle subjected to a rotation about a cubical axis. Four outer segments are elided to enable the visualization of the interlocking between outer segments and the segments of the central core. The outer equilateral segment fastened on top of a triangular segment of the central structure is labeled  50 ′. Segment  50 ′ is called anchor because it blocks any potential sliding or rotation on the spherical central support of the visible segments located in the same hemisphere of rotation with segment  50 ′. Therefore, all outer segments in the same hemisphere of rotation with the anchor remain aligned with the segments of the center support below them. By contrast, the outer segments of the opposite hemisphere of rotation are forced to slide on the spherical central support: segments  40  bordering the plane of rotation are forced to slide through the crossing track along the plane of rotation; the group of four segments  40  at the pole of the hemisphere is forced to slidably rotate on the spherical central support; and the remaining segments  50  are forced to slide simultaneously with their neighboring segments  40 . 
         [0037]    Rotation about tetrahedral axis:  FIG. 12  is a perspective view of the puzzle subjected to a rotation about a tetrahedral axis. Four outer segments are elided to enable the visualization of the interlocking between outer segments and the segments of the central core. The inner pieces of the spherical central support are forced to stay aligned with the pieces on top of them because the legs and feet of pieces  40  have no tracks available to slide on the center support, and as a result they will force segments  20  below them to rotate simultaneously. Outer segments  40  remain attached with their legs and feet to the tracks of the spherical central support, and outer segments  50  remain permanently attached with at least two protruded tongues to their neighboring segments. Another important feature of the tongues of segments  50  is the arcuate shape of their portion outside the sliding slot of their comprising segment. As a result, when the tongues of two segments  50  collide in the plane of rotation, they are pushed in said segments  50  until they can slide next to each other. Note that the temporary push of tongues  52  during this rotation affects only one out of three spring latching mechanisms of their comprising segments  50 , which is insufficient to disengage said segments  50  to fall out from the outer shell of the puzzle. 
         [0038]    Method of assemblage: The assemblage of spherical central support with segments  40  mounted on the crossing tracks coincides with the assemblage of Meffert&#39;s puzzle ball disclosed in U.S. Pat. No. 5,358,247 (U. Meffert and A. L. Chau), with the only difference that segments  40  are placed on top of inner segments  20  prior to the assemblage of the spherical central support. A segment  50  can be assembled by squeezing springs  58  through slots  56  into their cylindrical slots, followed by the insertion of tongues  52  through their sliding slots in said segment  50 . Afterwards, one segment  50  is fastened on top of a segment  10  of the center support, e.g., by means of a pin. Finally, every remaining segment  50  can be positioned in the outer shell of the puzzle by first pressing its tongues inside and next pushing said segment  50  inward between three segments  40  until it snaps into place. 
         [0039]    Method of use: The visible faces of the puzzle are preferably marked with a predetermined pattern or coloring so that only one or a few relative orientations of its outer segments define a solution. For example, in the preferred embodiment shown in  FIG. 1 , every octant of the outer shell comprising one segment  50  and three neighboring segments  40  may be colored differently. Furthermore, the puzzle can be made more challenging to solve by splitting the face of every outer segment  50  into three arcuate triangular faces with one corner in the middle of the outer surface of the said segment. This would yield a spherical puzzle with forty-eight faces. The puzzle may be scrambled by a series of rotations by integer multiples of 90° about cubical axes and integer multiples of 120° about tetrahedral axes. The object of the puzzle is to return by means of a series of such rotations to the unscrambled coloring or pattern. 
         [0040]    Since many modifications, variations and changes in detail can be made to the above described embodiment, it is intended that all matter in the foregoing description and shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.