Screw replacements in isomeric variants of Bricard's line-symmetric six-bar

Abstract

Much has been achieved over the past 40 years in searching for solutions to overconstrained, single-loop linkages of mobility 1, including the complete resolution of four-bar kinematic chains. In the cases of five- and six-bar linkages, however, analytical approaches are so confronting that some form of synthesis has often proved to be fruitful. The present exploration employs one such technique to isolate three previously unknown six-revolute loops, together with a determination of their displacement—closure relationships. Integral to the work is an examination of the extent to which the turning pairs might be replaced by screws. As well, the opportunity is taken to duly modify the existing record of six-revolute linkages.