Myard’s first five-bar linkage as a degeneracy of a plane-symmetric six-bar loop

Among the best known of overconstrained kinematic loops, Goldberg’s generalised five-bar is also recognised as a “parent” linkage to Myard’s first five-bar of 10 years earlier in appearance. Somewhat oddly, despite both having been synthesised from Bennett chains, the latter is plane-symmetric and the former essentially asymmetric in character. Explored in this paper is the notion that Myard’s linkage might be alternatively sought as a derivative of a plane-symmetric six-bar. Whilst there is high expectation of success in this instance, the approach may offer broader application. As well, the analysis highlights technical features of significance to workers in the field of linkage kinematics.