The lengths of the links comply with the conditions: B͞E=0͞A=d and ∠BEa=90°. Slider 1 moves along fixed guides p-p and is connected by turning pair B to link 2. Arm Ea of link 2 moves in slider 3 which turns about fixed axis A. When slider 3 turns about axis A, point F of link 2 describes a third-order focal-type curve. Curves s-s and s' -s', described by points F and D, are shown as examples. If points F and D lie on straight line BE they describe a conchoid and a strophoid with the equation : •y²=((a±c-x)/(a±c+x))(c-x)² where a=0͞A, c = distance from points F and D to straight line Ea.
$1176$LG,Ge$