Note that while a solution is usually obtainable for this case, it is possible that you
may not be able to move the linkage continuously from one position to the next without
disassembling the links and reassembling them to get them past a limiting position. That
will obviously be unsatisfactory. In the particular solution presented in Figure 3-8, note
that links 3 and 4 are in toggle at position one, and links 2 and 3 are in toggle at position
three. In this case we will have to drive link 3 with a driver dyad, since any attempt to
drive either link 2 or link 4 will fail at the toggle positions. No amount of torque applied
to link 2 at position C1 will move link 4 away from point Db and driving link 4 will not
move link 2 away from position C3. Input the file F03-08.4br to program FOURBARto
see Example 3-5