The lengths of the links comply with the conditions: A͞B=B͞C=B͞G, F͞C=M͞E and F͞M=E͞C. If link 4 is sufficiently long, point G of link 2 travels approximately along a straight line. Links 2, 3, 4 and 5 form a pantograph linkage. As a result, point M also travels approximately along a straight line, describing a path similar to that of point G, the similarity factor k being equal to k=D͞E/D͞C.
$692$LW,GI$