US Patent 10302224 Three-dimensional manufacturing of quieting valve having complex passages

A noise-reducing valve structure includes a unitary spindle-shaped body having a central lumen for receiving a fluid flow and a poppet member, the body having an inner diameter adjacent the central lumen and an outer diameter and a circumferentially and axially distributed plurality of radial passages adapted to be opened and closed in accordance with a guided position of the poppet member, the plurality of radial passages extending through the spindle-shaped body from the inner diameter to the outer diameter and having a gradually increasing area from the inner diameter to the outer diameter.