Using Geared Cardanic Motion to Generate Metamorphic Linkages

Cardanic motion profiles are a special case of the general epicycloids, hypocycloids, epitrochoids, and hypotrochoids. Under certain geometric constraints, circles, ellipses, and straight lines can be generated. In this paper we explore the use of the geared Cardan mechanism as a component generating metamorphic effects, or equivalent topology changes, in planar linkages by capitalizing on this change from linear to circular motion. The concept of instantaneous Grashof criterion in these mechanisms is also explored. The theory is detailed and example applications are described.