The force transmissibility of planar multiloop linkages

A procedure for analysing the force transmissibility of planar multiloop linkage mechanisms is introduced. The procedure considers the power flow paths in a multiloop linkage. By using a normalized force transmission index based on the 'gain per unit cost' concept, the force transmission performance of multiloop linkages can be characterized and measured quantitatively. The result shows that a multiloop mechanism may transmit effective force to the output link when it is at a singularity of motion. In such a condition, the power can reach the output link without passing through the singular-related joints in a multiloop mechanism.