The lengths of the links comply with the condition: A͞C<A͞B. Crank 1, of length A͞B, turns about fixed axis A. Sliding link 3 turns about fixed axis C. Slider 2, moving along the axis of link 3, carries rule D. When crank 1 turns about axis A, rule D, secured to slider 2, envelops hyperbola H. Length A͞B of crank 1 is varied by adjust ing pivot B in slot E of the crank. The distance between the vertices of the hyperbola is twice the length A͞B. The centre of pivot C is placed at one focus of the hyperbola. Hyperbolas of the required size can be obtained by adjust ing pivots B and C in slots E and G.
$1088$LG,Ge$