The lengths of the links of four-bar linkage ABCD comply with the conditions: A͞B=B͞E=C͞E=D͞C and A͞D=2B͞C. 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 points A and D.
$660$LW,GI$