Linear guides and rail methods are machine elements that assist the motion of major objects within a straight line with minimal friction or resistance. The CVT gearbox was very first patented in 1886 with the arrival in the motorcar. The CVT became far more mainstream due to DAF’s ‘Variomatic’ gearbox https://gearbox-cvt38249.madmouseblog.com/13170748/facts-about-gearbox-cvt-revealed