What I'd heard was that the Robertson screw, though awesome, didn't take off due to exorbitant royalties, but checking, it looks like he refused to license them

What I'd heard was that the Robertson screw, though awesome, didn't take off due to exorbitant royalties, but checking, it looks like he refused to license them to let anyone else make them after getting burned, & having only one supplier worried Henry Ford too much to use them. http://en.wikipedia.org/wiki/List_of_screw_drives#Robertson http://en.wikipedia.org/wiki/List_of_screw_drives#Robertson