  Using a geometric realization of the $SU(2)_R$ symmetry and a procedure of
factorisation of the gauge and $SU(2)_R$ charges, we study the small instanton
singularities of the Higgs branch of supersymmetric $U(1)^r$ gauge theories
with eight supercharges. We derive new solutions for the moduli space of vacua
preserving manifestly the eight supercharges. In particular, we obtain an
extension of the ordinary ADE singularities for hyperKahler manifolds and show
that the classical moduli space of vacua is in general given by cotangent
bundles of compact weighted projective spaces.
