From cube-lovers-errors@mc.lcs.mit.edu Tue Mar 17 11:02:50 1998 Return-Path: Received: from sun28.aic.nrl.navy.mil by mc.lcs.mit.edu (8.8.1/mc) with SMTP id LAA04827; Tue, 17 Mar 1998 11:02:49 -0500 (EST) Precedence: bulk Errors-To: cube-lovers-errors@mc.lcs.mit.edu Mail-from: From cube-lovers-request@life.ai.mit.edu Sun Mar 15 15:27:20 1998 From: roger.broadie@iclweb.com (Roger Broadie) To: "Cube Lovers Submissions" Subject: Ideal's patent for 4^3 Date: Sun, 15 Mar 1998 20:29:20 -0000 Message-Id: <19980315202713.AAA21006@home> On 19 Feb 1998 David Singmaster wrote: In my Cubic Circular 1 (Autumn 1981), I recorded that Wim Osterholt, of the Netherlands, had made and patented a 4^3 which he showed me. I don't remember it and I'm not sure when he brought it to London - perhaps Summer 1981? I also recorded that Rainier Seitz (product manager of Arxon which was Ideal's German agent) showed me some German patents and applications for the 4^3 and 5^3. In Cubic Circular 2 (Spring 1982), I record talking with another person who had devised a 4^3 mechanism. In Cubic Circular 3/4 (Spring/Summer 1982), I describe playing with examples. However, I don't recall ever knowing who devised the mechanism that was produced for Ideal. It was common knowledge that it was not Rubik's mechanism I have just come across Ideal's patent for its 4^3. It is US Patent No 4,421,311. The inventor was Peter Sebesteny, and the original application was made in Germany on 8 Feb 1981, so it may have been one of the patents David Singmaster was shown. It can be viewed at the IBM patent site from http://www.patents.ibm.com/details?patent_number=4421311 One of the references cited by the US Patent Examiner was to page 29 of David Singmaster's "Notes on Rubik's Magic Cube" - undoubtedly the remark "One can imagine the 4x4x4 cube or the 3x3x3x3 hypercube. The first might be makeable but its group seems to be much more complicated. The second is unmakeable, but its group structure may be determinable." The corresponding European patent application was taken through to the point where it was ready for grant, but then allowed to lapse. The next stage would have been quite expensive and have required Ideal to translate the specification into the languages of the European countries in which it was to be in force. And the US was not renewed when the first renewal fees became due in 1986. Presumably by then Ideal had lost interest in the patent - they may have calculated there was zero chance of anyone launching an imitation, given the number of 4^3s that had been left unsold. I don't have ready access to information about the German application, but I suspect it was applied for by Sebesteny on his own behalf, and he then interested Ideal in it. Roger Broadie