The lengths of the links comply with the conditions: B͞C=2.3A͞B and C͞D=2.2A͞B. When crank 1 rotates about fixed axis A, point D of connecting rod 3 of the slider-crank mechanism ABC describes connecting-rod curve q-q of which a certain portion, between the positions D₁ and D₂ (of point D) approximates a straight line.
$1555$SC,GI$