The lengths of the links comply with the conditions: A͞D=2.16A͞B, B͞C=D͞C=M͞C=4.34A͞B and angle β=∠ MCD=100°. When link 1 rotates about fixed axis A, point M of connecting rod 2, in four-bar linkage ABCD, describes connecting-rod curve q-q of which portion M₁M₂ , of a length l≅2.66A͞B, is approximately a line.
$657$LW,GI$