Patent ID: 7134623

Claim:
A hammermill comprising: a housing having an inlet end, a discharge end, a sidewall extending between the inlet end and the discharge end, and a longitudinal axis, the sidewall of the housing defining an enclosed work space, an inlet opening being defined in the sidewall of the housing proximate the inlet end of the housing, a discharge opening being defined in the sidewall of the housing proximate the discharge end of the housing, the inlet opening being disposed above the longitudinal axis of the housing and the discharge opening being disposed below the longitudinal axis of the housing; a rotor assembly disposed within the housing for rotation about the longitudinal axis of the housing; a plurality of opposing pairs of disks mounted to and circumscribing the rotor assembly, each pair of disks being spaced apart a predetermined distance; a first plurality of hammers coupled to the rotor assembly and disposed in the enclosed work space, wherein at least one hammer of the first plurality of hammers is positioned between respective pairs of disks; a second plurality of hammers coupled to the rotor assembly, the second plurality of hammers disposed proximate the inlet end of the housing and adjacent to and upstream of the first plurality of hammers, wherein at least one hammer of the second plurality of hammers is positioned between respective pairs of disks; and at least one annular ring having an peripheral ring edge, wherein each annular ring is connected to the rotor assembly between a portion of at least one hammer of the respective first and second plurality of hammers and at least one disk of the respective pair of disks, wherein the longitudinal widths of the annular ring and the hammer substantially equal the predetermined distance between the pair of disks; wherein each hammer of the first and second plurality of hammers has an outer tip which defines a hammer rotation radius about the longitudinal axis of the housing, wherein the peripheral ring edge of the annular ring extends outwardly from the rotor assembly toward the sidewall of the housing, wherein the peripheral ring edge defines a maximum radius of curvature about the longitudinal axis of the housing that is about or less than the hammer rotation radius, and wherein the diameter of each disk is less than the diameter of the annular ring.