The lengths of the links comply with the condition: A͞B=B͞C=C͞O=O͞A=A͞P=C͞Q. Figure ABCO is a rhombus linkage. Link 1 rotates about fixed axis E and is connected by turning pair P to link 5. Links 2 and 3 turn about fixed axis 0 and are connected by turning pairs C and A to links 4 and 5. When link 1 rotates about axis E, point P describes circle p-p of radius E͞P and point Q describes circle q-q of radius D͞Q=E͞P. Points E, O and D lie on a straight line. Therefore, by adding link 6, shown by dash lines, the mechanism can be made to transmit rotation with constant transmission ratio i₁₆ between links 1 and 6 equal to i₁₆=ω₁/ω₂=-1. Directions EP and DQ of links 1 and 6 are always parallel. Links 1 and 6 rotate in opposite directions.
$686$LW,GI$