Saturday, December 24, 2005

Everyday Patents: Rubik’s Cube

Ernő Rubik invented a variety of rotating cube toys in mid-1970s. He was a Hungarian sculptor and professor of architecture with an interest in geometry and 3D forms. According to a Wikipedia article, Rubik obtained Hungarian patent HU170062 for the Magic Cube in 1975, but did not take out international patents.

The US Patent Office shows a series of patents by Rubik filed in 1984, referring to earlier filings in Hungary:

  • 5,184,822 “Three-dimensional puzzle” (1993, Hungary 1983): single cube with holes in side
  • 4,471,959 “Logical toy” (1984, Hungary 1980): Horizontal pushers in two layers
  • 4,410,179 “Shiftable element puzzle” (1983, Hungary 1977): Cylindrical puzzle, with two layers of six petals
  • 4,392,323 “Toy with turnable elements for forming geometric shapes” (1983, Hungary 1980): One-dimensional chain of triangular pieces
  • 4,378,117 “Spatial logical toy” (1983, Hungary 1980): Various 2x2x2 arrangements
  • 4,378,116 “Spatial logical toy” (1983, Hungary 1978): A two-layer puzzle, with 3x3 cells in each layer

Larry Nichols received US patent 3,655,201 in 1972 for a “pattern forming puzzle and method with pieces rotatable in groups”. The filing concentrates on a 2x2x2 design, but the drawings show larger compositions. The thing is held together with magnets. According to Wikipedia, Ideal Toys lost a patent infringement suit based on this patent in 1984.

Terutoshi Ishigi acquired Japanese patent JP558192 for a nearly identical mechanism while Rubik's patent was being processed, but Ishigi is generally credited with an independent reinvention.