The mechanism is based on crossed-crank linkage ABCD with the small link fixed. Added to the linkage is a double guiding element consisting of two sliders, 5 and 6, connected together by turning pair E. The mechanism is intended for tracing ellipses. Pivots A and D are placed at the foci of the ellipse. The tracing point is at the centre of pivot E. Ellipses of various sizes can be obtained by properly selecting the lengths of links 1, 2, 3 and 4. The lengths are varied by moving pivots B, C and D as required along slots F, G, H and K of links 1, 2, 3 and 4.
$1043$LG,Ge$