Point B on blue bar of an ellipse mechanism traces an ellipse (in black). Three other curves are traced by the points on the yellow bar that has revolution joint with the blue bar at B and prismatic joint with the red part.
They are considered as the result of the black ellipse deformation with constant distance along the direction toward the ellipse center.
They are equidistant or parallel curves with respect to the black ellipse.
Input: the red part. One working cycle corresponds two input revolutions.
In this video:
BC = a; BE = b; BD = (a+b)/2
a: length of semi-minor axis of the black ellipse.
b: length of semi-major axis of the black ellipse.
Points C, D and E trace eight-shaped curves.