Slider 1 moves along fixed guides t-t and has cross-piece Ab connected by a sliding pair to slider 9. Slider 1 is connected by turning pairs A to links 3 and 5. Link 3 moves in cross-shaped slider 7 which has guides perpendicular to each other. Llrik 2, connected by turning pairs D to links 5 and 6, moves in sliders 7 and 8. Sliders Sand 9 are connected together by turning pair C. Link 6 turns about fixed axis B. Link 3 moves in slider 4 which turns about axis B. Point B is placed at the focus of a parabola, axis a-a of guides t-t is made to coincide with the directrix of the parabola, and the lengths of links 5 and 6 are taken equal to each other. Then, when slider 1 moves along guides t-t, point C describes parabola q-q with the distance p between the focus and directrix. At the same time, straight line Dd envelops the parabola.
$1109$LG,Ge$