The lengths of the links comply with the conditions: A͞C=C͞B, A͞G=D͞G=B͞F=A͞C/sqrt(2), G͞F=sqrt(2)A͞C and D͞E=A͞E. Figure GDEA is a rhomboid linkage. When link 1 turns about fixed axis A, point B describes straight line q-q. Intermediate points of link 3 describe ellipses.
$765$LW,Ge$