SPHERE, OVAL SPHERE OR SEMISPHERE FORMED BY CUTTING OFF CORNERS OF 30 OR 20 PARALLELEPIPEDS AND BONDING CUT ONES AND SEMIOVAL DECORATIVE BALL

摘要

PURPOSE:To obtain a decorative ball having a spherical, oval-spherical, semispherical or semioval-spherical shape by forming specific notches to four corners of one end surface of each of parallelepipeds and mutually abutting the notches of the parallelepipeds. CONSTITUTION:A decorative ball is formed by radially bonding parallelepipeds to the respective surfaces of a lozenge triacontahedron. Notches 3 are formed to four corners of the bottom of a parallelepiped 2 and the these notches are mutually bonded to make it possible to arrange 30 parallelepipeds in a spherical shape. In the dimension of the notch 3, when the length of one side of the bottom surface of the parallelepiped 2, the length of the other one side of the bottom surface thereof, height and cut-off height are set to (a), (b), (c), (d), x=0.618d, y=0.382d, x=a/2 and y=b/2 [wherein x is cut-off quantity from both ends of (a) and y is cut-off quantity from both ends of (b)]. When 30 (20 in the case of a semisphere) parallelepipeds are radially arranged through the cut ends so that a regular triangle is formed from (l3) corner cut parallelepipeds and a regular pentagon is formed from (m5) parallelepipeds, they naturally become a spherical (semispherical) shape. By properly changing the length of (c), an oval-spherical shape is obtained.