Note in equation 5.34a that there are two solutions for each angle (just as there were
to the position analysis of the fourbar linkage in Section 4.5 and Figure 4-8, p. 155). One
solution in this case will be a trivial one wherein ~2 = (X2 and ~3 = (X3. The nontrivial
solution is the one desired.
This procedure is then repeated, solving equations 5.34 for the right-hand end of the
linkage using the desired location of fixed pivot 04 to calculate the necessary angles 'Y2
and 'Y3for link 4.
We have now reduced the problem to that of three-position synthesis without spec
ified pivots as described in Section 5.6 and Example 5-2. In effect we have found the
particular values of ~2' ~3' 'Y2, and 'Y3which correspond to the solution that uses the de
sired fixed pivots. The remaining task is to solve for the values of Wx, Wy, Zx, Zy using
equations 5.25 through 5.31.