The lengths of the links comply with the conditions: E͞A=A͞C=A͞D=E͞C/2 and F͞B=B͞C=B͞D=C͞F/2. Sliders 1 and 2 move along fixed guides a-a and b-b. Link 3 is connected by turning pairs G and H to sliders 1 and 2. Links 4 and 5 are connected by turning pairs E and F to sliders 1 and 2, and by turning pairs A and B to links 6 and 7. Point D is always on the straight, line joining points E and F, line AB is parallel to line EF and line CD is perpendicular to line EF. When sliders 1 and 2 move along their guides (which are perpendicular to each other) point D describes the wing profile proposed by N. E. Zhukovsky.
$1615$SC,Ge$