The lengths of the links comply with the conditions: A͞D=D͞B=B͞C=C͞A, i.e. figure ADBC is a rhombus linkage. Links 5 and 6 turn about fixed axis A. Links 7 and 8 are connected by turning pairs B to slider a of link 1 which moves along fixed guides q-q. Slider 3 is connected by turning pair K to slider 4 through which link 9 moves. Link 9 is diagonal DC of rhombus linkage ADBC. When slider a moves along guides q-q, point K describes a parabola with the equation y²=2px , where p is the distance from point A to the axis of guides q-q.
$1097$LG,Ge$