  In this paper, we construct two types of 7R closed single loop linkages by
combining different factorizations of a general (non-vertical) Darboux motion.
These factorizations are obtained by extensions of a factorization algorithm
for a generic rational motion. The first type of 7R linkages has several
one-dimensional configuration components and one of them corresponds to the
Darboux motion. The other type is a 7R linkage with two degrees of freedom and
without one-dimensional component. The Darboux motion is a curve in an
irreducible two dimensional configuration component.
