The lengths of the links comply with the conditions: F͞G=F͞H=q, C͞D=C͞E=p, B͞D=B͞E=m and B͞G=B͞H=l. The mechanism always complies with the supplementary conditions: m/l=p/q and B͞C×B͞F=pq-ml=k², where k is the inversion constant. When crank 1 turns about fixed axis A, point F describes circle d which is the inversion of the circle described by point C. The centre of circle d lies on the straight line through points A and B. The radius of the circle can be changed by turning screw 2 to move the sliding member on which axis A is secured, thereby changing distance A͞B. If distance A͞B is made equal to A͞C, then circle d is transformed into a straight line perpendicular to line A͞B.
$740$LW,GI$