Some cone CVT designs use two rollers.[23][24] In 1903, William Evans and Paul Knauf applied to get a patent over a consistently variable transmission making use of two parallel conical rollers pointing in opposite directions and connected by belts which could be slid alongside the cones to vary the transmission https://gearboxcvt38147.theideasblog.com/33155390/getting-my-gearbox-cvt-to-work