This 1980 patent was filed by Reginald Vorontsov and Georgy Panin of TSKTB (ЦКТБB or ‘Central Design Office for Bicycle Construction’) just two months after the closing ceremony of the Moscow Olympic games. Both men had been working feverishly on the special ‘Moscow 80’ bikes that they were preparing for the Soviet Olympic team - and you can only assume that this patent came from their efforts.
It appears to describe a derailleur with both adjustment screws in the rear knuckle, somewhat in the style of a Czech Favorit Special or a Walter. The cable clamp arrangement also looks interesting. I don’t think that either feature was evident on the Tachyon derailleurs that were actually manufactured.