One end of flexible link 2 is secured at point A to treadle 1. Then link 2 runs over pulley 3 and its other end is secured at point B to flywheel 4. When treadle 1 is depressed, flywheel 4 is rotated. The dot-and-dash lines indicate the upper and lower positions of treadle 1. The treadle is raised to its initial position by the inertia of flywheel 4.
$1862$FL,5L$