It was presented by William Leybourn in his book “Pleasure with Profit”, 1694.
Under the gravity the roller moves to the right. It looks that it moves up along the inclined rails. In fact the roller center of mass moves down. Blue line is its trajectory.
Motion condition: tg(B) must be less than tg(A).tg(C)
A: vertex angle of the roller cone.
B: inclined angle of the rails
C: angle between the rails