The best overall discussion of cube patents is in Metamagical
Themas,pg 356; D Hofstadter. Hofstadter says "that the real reason
the Rubik-Ishige Cube took off was that it could be manufactured and
that it did hold together". In Puzzles Old and New,
Slocum&Boetermans it is stated that the courts gave the US patent
rights to Nichol's. The is a further discussion of Rotary Puzzle
patents in Doug Engel's self published book "Circle Puzzler's Manual".
If anybody has further patent details please send me citations or even
rumors. Of especial interest is information on the granting of the US
rights to Nichol's.
I've added some more details to the patent section. 0. CUBE PATENTS (see Metamagical Themas,pg 356; D Hofstadter for an overview) 0.1 US PATENT#3,081,089, william Gustafson, 1958 (2x & 3x) 0.2 Frank Fox, 1970 British (3x) 0.3 US PATENT# , LARRY Nichols, 1972 (2x) 0.4 HUGARIAN PATENT, #170062, ERNO RUBIK, Jan 30,1975&Oct 28,1976&Dec 31,1977 (3x &2x cubes) 0.5 JAPANESE PATENTS 0.5.1 JAPANESE PATENT,#55-8192, Terutoshi Ishige, Oct 10,1976&Apr 26,1978&Mar 3,1980,(3x) 0.5.2 JAPANESE PATENT,#55-8193, Terutoshi Ishige, Mar 12,1977&Oct 10, 1978&Mar 3,1980; (2x) 0.5.3 JAPANESE PATENT,#55-3956, Terutoshi Ishige, Oct 21,1978&Jan 28,1980,(3x)
THE FUTURE IS PUZZLING,
but CUBING IS FOREVER !!
<pbeck@ardec> or <beck@ardec-lcss>