The lengths of the links comply with the conditions: A͞D=0.8A͞B, A͞B=D͞C=H͞G, C͞E=E͞B=G͞F=0.2A͞B and E͞F=C͞G=D͞H. The mechanism is based on four-bar linkage ABCD. When link 1 turns about fixed axis A, point E of connecting rod 2 describes a path of which a certain portion approximates straight line q-q, belonging to the fixed link and parallel to line AH. For the specified dimensions, figures DCGH and CEFG are parallel-crank linkages and link 4 has translational motion. During the period of time that point E travels along the approximately rectilinear portion of its path, all points of link 4 travel approximately rectilinearly and axis EF of link 4 slides along straight line q-q. Links 3 and 7 turn about fixed axes D and H.
$723$LW,GI$