The lengths of the links comply with the conditions: B͞D=E͞G=(A͞Bsqrt(5)-A͞B)/2, C͞F=G͞F=(A͞Bsqrt(5)+A͞B)/4, B͞C=D͞E=l₂=A͞B/3, l₁=A͞B; Link 1 turns about fixed axis A and is connected by turning pairs D and B to links 2 and 4. Link 3 turns about fixed axis G and is connected by turning pairs E and F to links 2 and 5. Link 4 is connected by turning pairs B and C to links 1 and 5. When link 1 turns about axis A, point C of link 4 describes a path of which a certain portion approximates a straight line.
$693$LW,GI$