The lengths of the links comply with the conditions: E͞F=0͞G, 0͞E=E͞C=F͞C=B͞A=0͞B=a/2. Figure EFGO is a parallel-crank linkage. Link 1 turns about fixed axis B and is connected by turning pair A to slider 4. Slider 4 moves along the axis of link 3 which turns about fixed axis 0. Link 5 is connected by turning pairs E, F and C to links 2 and 6 and to slider 7 which moves along fixed guides p-p whose axis coincides with axis 0y. Link 2 turns about axis 0. Link 6 is connected by turning pair G to link 3. Link 8 is connected by turning pair A to slider 4 and moves in cross-shaped slider 9 which has guides perpendicular to each other. Slider 9 moves along cross-piece Cd of slider 7. When link 1 turns about axis B, point D of slider 9 describes lemniscate of Gerono q-q (eight curve) with the equation y⁴=a⁴(y²-x²).
$1169$LG,Ge$