A Journal of Applied Mechanics and Mathematics by DrD, #43
(c) Machinery Dynamics Research, 2017
Four-Bar / Toggle Linkage Mechanism
I believe that it would be correct to say that all of the single degree of freedom mechanisms that I have discussed on ME Forums have involved only a single loop. This might lead a reader to conclude that a single degree of freedom implies only a single loop, and vice versa, that a single loop implies only a single degree of freedom. Neither of these statements is true. In this note, I want to discuss a counter example, a mechanism called the four-bar / toggle linkage; it is shown in Figure 1.