The lengths of the links comply with the conditions: A͞D=B͞C=D͞L=B͞P, D͞C=A͞B=D͞Q=B͞0 and ∠ADL=∠CBP=∠CDQ=∠AB0=90°. Figure ABCD is a parallelogram linkage. Link 1 turns about fixed axis 0. Link 5 is connected by turning pair P to slider 2 which moves along fixed guides p-p. When link 1 turns about axis 0, point L of link 3 and point Q of link 4 describe straight lines l-l and q-q. Line q-q is perpendicular to axis p-p of the guides and line l-l makes an angle of 45° with axis p-p. Points 0, Q, L and P always form a square.
$1558$SC,GI$