The lengths of the links comply with the conditions: A͞B=C͞B=B͞M=1, E͞A=0.305, C͞E=0.76, β=114°, M͞D=0.66, F͞D=0.8, C͞F=1.66 and E͞F=2.36. Point M of connecting rod 2 in four-bar linkage EABC describes connecting-rod curve a-a of which a certain portion, shown by a heavy continuous line, approximates a circular arc of radius D͞M (link 3) with its centre at point D. When point M is on this portion of path a-a, link 4 is almost stationary, i.e. it practically has a dwell at one extreme position. The length of the dwell is approximately equal to one half-revolution of crank 1.
$757$LW,D$