The lengths of the links comply with the conditions: A͞B=E͞C, B͞C=0.44A͞B, B͞M=M͞C, M͞D=F͞D=D͞L=0.61A͞B, A͞E=2A͞B, E͞F=1.72A͞B and A͞F=1.44A͞B. Link 1 turns about fixed axis A and is connected by turning pair B to link 2. Link 3 turns about fixed axis E and is connected by turning pair C to link 2. Link 4 is connected by turning pair M to link 2 and by turning pair P to link 5 which turns about fixed axis F. When link 1 turns about axis A, point L of link 4 describes a path of which a certain portion approximates a straight line.
$689$LW,GI$