The lengths of the links comply with the condition: A͞C=A͞B=O͞F=F͞E=a. Gears 1 and 5 are of equal radius r. Gear 1 rotates about fixed axis B and meshes with gear 5 which rotates about fixed axis 0. Lever Bn, rigidly attached to gear 1, is connected by a sliding pair to slider 3 which, in turn, is connected by turning pair C to link 4 turning about fixed axis A. Link 8 is connected by turning pair C to slider 3 and moves in cross-shaped slider 2 which has guides with axes perpendicular to each other. Slider 2 moves along cross-piece Ee of slider 7 which moves along fixed guides p-p whose axis coincides with axis Oy. Link 6 is connected by turning pairs E and F to slider 7 and lever OF which is rigidly attached to gear 5. When gear 1 rotates about axis B, point D of slider 2 describes virtual parabola q-q of Vincentio with the equation [2r²x+(2r²-y²) sqrt(r² — b²)]²=b²y²(4r²-y²) where b is a constant dimension of the mechanism.
$1773$GL,Ge$