Study on Connecting Rod Curves Generated by Mechanisms with three Dyads of the Same Type

We start from the kinematic scheme of a mechanism with three dyads, all of the RRR type connected in this way: the first dyad to the driving element R and to the base, the second dyad to the connecting rod of the first dyad in the mechanism and to its rocker, and the third at the connecting rods of the second dyad. This way of binding makes it possible to obtain more and more complex connecting rod curves. Analytical relations are written based on the closed – loops method.  We draw the connecting rod curves generated by the points of interest on this mechanism. Similarly, are studied the connecting rod curves drawn by a mechanism consisting of three RPP-type dyads and another mechanism with three RPR-type dyads. There were a lot of connecting rod curves of very different shapes, open curves because the mechanisms were not built so that the driving element could perform complete rotations (conditions like Grashof). These connecting rod curves can be used on packaging machines, at some toys and in other fields.