The lengths of the links of four-bar linkage ABCD comply with the conditions: B͞C=D͞C=C͞M=1.55A͞B, A͞D=l.36A͞B and angle β=110°. When link 1 turns about fixed axis A, point M of link 2 describes a path which approximates a circular arc of radius R₁ or R₀ where ∆R=R₀-R₁ is a small value.
$681$LW,GI$