The lengths of the links comply with the condition: A͞C<A͞B. Crank 1, of length A͞B, rotates about fixed axis A. Sliding link 3 rotates about fixed axis C. Slider 2, moving along link 3, carries rule D. When crank 1, whose length A͞B is changed by adjusting pivot B along slot e, rotates about axis A, rule D, secured rigidly to slider 2, envelops ellipse H. The length of the major axis of the ellipse is twice that of the crank length A͞B. The centre of pivot C is located at one focus of the ellipse and the centre of pivot A at its centre. Ellipses of the required parameters can be obtained by adjusting pivots B and C along slots e and g.
$1060$LG,Ge$