Some cone CVT styles use two rollers.[23][24] In 1903, William Evans and Paul Knauf used for the patent with a repeatedly variable transmission using two parallel conical rollers pointing in opposite directions and linked by belts that may be slid along the cones to vary the transmission ratio.   In https://gearboxcvt86307.bloggerchest.com/32589125/a-simple-key-for-gearbox-cvt-unveiled