The mechanism is based on crossed-crank linkage ABCD. Added to this linkage is a double guiding element consisting of two sliders, 5 and 6, connected together by turning pair E. The mechanism is intended for tracing hyperbolas. Pivots A and D are placed at the foci of the hyperbola. The tracing point is at the centre of pivot E. In the position shown, the mechanism traces the right branch Hi of the hyperbola. To trace the left branch Hz the mechanism should be turned through 180°. Hyperbolas of various sizes can be obtained by varying the lengths of links 1, 2, 3 and 4. This is done by adjust ing pivots B, C and D in slots F, G, K and L of links 1, 2, 3 and 4.
$1087$LG,Ge$