Some cone CVT models use two rollers.[23][24] In 1903, William Evans and Paul Knauf used for any patent over a repeatedly variable transmission making use of two parallel conical rollers pointing in opposite directions and related by belts that may be slid along the cones to range the transmission ratio. https://messiahoqmhz.is-blog.com/39132356/5-simple-techniques-for-gearbox-cvt