Some combinatorial results for shifted Young diagrams

The speed of the individual rolls in multiple roll bridle systems is made adjustable and independent of roll diameter for maximum alteration of strip passing over the rolls, by providing first, plural, independent drive means for a plurality of corresponding rolls in each of a set of entry rolls and a set of exit rolls, and second drive means providing common power input to a plurality of rolls in each said sets. The second drive means is adapted to provide, through a gear train including infinitely variable speed transmission means and differential transmission means, dual power takeoffs to corresponding dual planetary gear systems.