The lengths of the links of slider-crank linkage ABC comply with the conditions: B͞C=4A͞B, B͞D=7.1A͞B, C͞D=5.25A͞B and a=3.25A͞B. When crank 1 turns about fixed axis A, point D of connecting rod 2 describes a path of which a certain portion approximates straight line q-q, perpendicular to axis b-b of motion of slider 3.
$1554$SC,GI$