Elliptic pulley 1 rotates about fixed axis A which passes through the centre of ellipse a. Pulley 2 rotates about fixed axis B. Flexible link 4 runs over pulleys 1 and 2. Idler pulley 3 rotates about axis D of lever 5 which turns about fixed axis C. Spring 6 presses pulley 3 against flexible link 4 to maintain constant tension of the link. When pulley 1 rotates at uniform speed, pulley 2 rotates at nonuniform speed.
$3498$SFL,ML$