US Patent 9174229 Dispenser having non-frustro-conical funnel wall

A helix cup for use in a pressurized dispenser. The helix cup has a convergent funnel wall. The funnel wall is not straight and does not satisfy the mathematical equations for surface area or for subtended volume of the frustrum of a cone. Instead, the funnel wall provides a longer flow path than is achieved with straight sidewalls. The longer flow path provides for a tighter particle size distribution at lower pressures than occurs in the prior art.