US Patent 7584916 Cutting ring element for a centrifugal chopper pump

A cutting ring element for a centrifugal pump of the chopper type comprises a ring-like structure having at least one cutting member positioned along the ring-like structure and extending outwardly therefrom. The cutting ring element is structured to be positioned adjacent the drive side of an impeller having cutting structures associated with the drive side of the impeller which interact with the cutting ring element to chop and reduce the size of entrained solids in a pumped fluid, or slurry, to prevent such solids from infiltrating behind the impeller.