The lengths of the links of four-bar linkage ABCD comply with the conditions: A͞D=1.41A͞B, B͞C=0.55A͞B, D͞C=0.48A͞B, C͞E=0.96A͞B, B͞E=0.45A͞B and A͞F=0.55A͞B. When link 1 turns about fixed axis A, point E of link 2 describes a path of which a certain portion approximates straight line q-q, passing through point F on straight line AD.
$671$LW,GI$