The lengths of the links comply with the conditions: A͞B=D͞C, A͞F=D͞E, A͞G=D͞H and B͞C=F͞E=G͞H=A͞D. The mechanism transmits rotation from shaft A to shaft D. Keyed on shafts A and D are disks 1 and 2 which are connected by turning pairs to connecting rods 3, 4 and 5. The mechanism has no uncertainty of motion at its extreme positions (dead points).
$639$LW,PC$