The lengths of the links comply with the conditions: A͞B= a and A͞E=sqrt(a²+b²), where a and b are the major and minor semiaxes of the ellipse being enveloped. Link 1, rotating about fixed axis A, is connected by turning pair B to slider 2 which moves along the axis of link 3. Link 3 rotates about fixed axis C. Link 5, rotating about axis A, is connected by turning pair E to slider 4 which moves along axis t-t of the cross-piece of slider 2. Point A is placed at the centre of the ellipse and point C at one of its foci. Then, when link 1 rotates, axes t-t and q-q of the cross-pieces of sliders 2 and 4 simultaneously envelope ellipse p-p.
$1054$LG,Ge$