The lengths of the links comply with the conditions: B͞E=(ab²)/(a-b²),E͞F=(cdb)/(d²-b²), F͞G=(adb)/(d²-b²) and G͞C=(cb²)/(d²-b²), where a=A͞B, b=B͞C, c=C͞D and d=A͞D. Link 1 turns about fixed axis A and is connected by turning pairs B and E to links 3 and 2. Link 4 turns about fixed axis D and is connected by turning pairs C and G to links 3 and 5. Links 2 and 5 are connected by turning pair F. When link 1 turns about axis A, point F describes straight line Oq which is perpendicular to AD. Intersect A͞O equals A͞O=(d/2)((a²-b²-c²+d²)/(d²-b²)).
$707$LW,GI$