When stylus A follows the given curve y=f(x), stylus D traces the integral curve y=F(x) on carriage 1. Carriage 1 moves along guide 2 by means of sharp-edged wheel 3 which swivels about axis B of carriage 4. Carriage 4 travels in the direction of the x-axis. Travellinhg along carriage 4 in the direction of the y-axis is carriage 5 whose pin F slides along the slot of link 6 which turns about axis B. The distance between ploints F and B equals b=f(x). Since the axis of slotted link 6 is a ways parallel to the plane of wheel 3, then the angle α=arctan(y/b).
$1301$LG,MO$