Some cone CVT layouts use two rollers.[23][24] In 1903, William Evans and Paul Knauf applied for any patent on the continually variable transmission making use of two parallel conical rollers pointing in opposite directions and related by belts that would be slid along the cones to differ the transmission ratio. https://gearbox-cvt91111.bloggosite.com/39485354/top-guidelines-of-gearbox-cvt