The lengths of the links, comply with the condition: A͞C:B͞C=C͞P:B͞Q. Link 2 turns about fixed axis A which is the centre of inversion transformation. Links 3 and 5 are connected by turning pairs B and C to link 2 and by turning pairs Q and P to sliders 4 and 6. Sliders 4 and 6 move along axis Aa of link 1 which turns about axis A. When point P or Q travels along any arbitrary curve, the other point describes a curve which is the inversion of the first curve. Hence, the mechanism accomplishes inversion transformations of the form A͞PxA͞Q=const.
$1370$LG,GI$