This invention relates to a group or groups of blocks, each of which is shaped as a tetrahedron.
Each set has twelve blocks and is capable of assembly into a rectangular parallelepiped; each set is also capable of assembly as an eight-block pyramid and a four-block tetrahedron. Many other solids may be formed from either such group.
The tetrahedron, the simplest polygonal solid, is of special interest, in that all other polygonal solid figures can be broken down into tetrahedrons. In this manner, a number of shapes can be produced by assembling various tetrahedrons. The group of blocks may be viewed either as an educational device for study of solids, as a playset for amusement of children or grownups, or as a puzzle for grownups or children.
In its educational aspect, a great deal can be learned about various solid figures, including not only pyramids and cubes but a great variety of figures, by superposition and interrelation of the tetrahedrons included in the sets of this invention. The blocks may be related to architecture and history, and also may lead to geometrical speculation.
When used either for play or as a puzzle, the invention provides numerous opportunities for assembling various shapes from the tetrahedrons. Storage is normally done by assembling them together in cubes or parallelepipeds or segments thereof; and when the blocks are all spread out it takes ingenuity and understanding to reassemble them into the cube, particularly a cube related to the particular set. As stated, pyramids or pyramidal groups may be constructed; so may octahedrons, and so on.
Thus, among the objects of the invention are those of enabling study and amusement, of facilitating observation, of improving manual dexterity, of illustrating relations between various solid figures, and so on, by the use of tangible blocks. These blocks are preferably made so that they can be held to each other magnetically; and they are also preferably colored, when the color relationship is helpful. To make the group more puzzling, of course, the color relationship may be avoided.