Flexible link 2 is secured to treadle 1 at point A. Then link 2 is wound 360° around pulley 3 and is secured to elastic link 4 at point B. Pulley 3 rotates clockwise when treadle 1 is depressed, bending link 4 downward. When treadle 1 is released, link 4 straightens out and pulley 3 rotates counterclockwise.
$1861$FL,5L$