Composition of spherical four-bar-mechanisms

Abstract

We study the transmission by two consecutive four-bar linkages with aligned frame links. The paper focusses on so-called "reducible" examples on the sphere where the 4-4-correspondance between the input angle of the first four-bar and the output-angle of the second one splits. Also the question is discussed whether the components can equal the transmission of a single four-bar. A new family of reducible compositions is the spherical analogue of compositions involved at Burmester's focal mechanism. © Springer Science+Business Media B.V. 2010.