The lengths of the links comply with the conditions: A͞D=2A͞B, B͞C=D͞C=C͞E=2.5A͞B, B͞E=G͞F, B͞G=E͞F=A͞H and H͞G=A͞B. The mechanism is based on four-bar linkage ABCD of which point E on connecting rod 2 has approximate rectilinear motion over a certain portion of its path when link 1 turns about fixed axis A. This motion approximately coincides with straight line q-q, belonging to the fixed link and parallel to AH. With links of the specified lengths, figures ABGH and BEFG are parallel-crank linkages and link 4 has translational motion. During the period of time that point E travels along the approximately straight portion of its path, all points of link 4 also travel approximately straight and axis EF of link 4 slides along straight line q-q. Links 3 and 6 turn about fixed axes D and H.
$712$LW,GI$