Some cone CVT patterns use two rollers.[23][24] In 1903, William Evans and Paul Knauf applied to get a patent on a consistently variable transmission working with two parallel conical rollers pointing in opposite directions and linked by belts that might be slid together the cones to differ the transmission ratio. https://gearbox-cvt49258.blogolenta.com/29619381/the-ultimate-guide-to-gearbox-cvt