The lengths of the links comply with the conditions: A͞C=C͞B=C͞P and P͞D=D͞Q. Links 1 and 5 turn about fixed axis A. Link 1 has the form of a bent lever. Arm Ba of link 1 moves in slider 2. Link 3 is connected by turning pairs C and P to links 1 and 4. Link 6 is connected by turning pairs Q and D to slider 2 and to links 4 and 5. The mechanism complies with the inversion condition A͞PxA͞Q=A͞B²=A͞D²-P͞D². Therefore, with fixed point A as the centre of inversion, when point P travels along any arbitrary curve, point Q describes a curve which is the inversion of the curve followed by point P, and vice versa.
$1373$LG,GI$