Abstract: A hammer mill grinder includes a feed conveyor, a press wheel and a rotary hammer mill that is enclosed within a mill box. The mill box presents an intake opening for receiving feed material and a discharge opening for discharging reduced material. The press wheel is located adjacent to the mill box intake opening and is mounted at least indirectly to the mill box for vertical movement. The rotary hammer mill presents hammers that rotate, in cyclic succession, past the intake opening, the press wheel, an inside wall and a screen that is offset from the rotary hammer. The inside wall includes a contaminant bypass door that is able to open to allow a contaminant object to bypass the hammer mill prior to the screen and thereby exit the mill box around the screen to prevent damage to the hammer mill grinder.

Abstract: A feed roller assembly for a horizontal grinder having a hammer mill and a conveyor moving material to be ground or processed toward the infeed side of the hammer mill includes a side tilt frame hingedly connected along a first axis to a hammer mill frame and a feed roller frame hingedly connected along a second axis to the side tilt frame. In a first position, the side tilt frame and the feed roller frame are downwardly hinged so as to engage the feed roller with feed material. In a second position, the feed roller frame is hinged upward about the second axis to disengage the feed roller from the feed material and the hammer mill frame. In a third position, the side tilt frame is further hinged outward about the first axis to pivot the entire feed roller assembly away from the hammer mill frame.

Abstract: An improved tub grinder includes a hammer mill having a swing diameter which is adjustable. The tub grinder includes: first and second sets of interchangeable hammers, the second set being shorter than the first; first and second interchangeable semi-cylindrical screen assemblies, the second screen assembly having a smaller diameter than the first; and a pair of shear bars and adapter plates. In a first configuration, the first set of hammers are mounted to a rotor assembly and have a first swing diameter. The first semi-cylindrical screen assembly is secured within a cylinder box in co-axial alignment and outwardly spaced relationship with the first set of hammers. The shear bars are mounted to the tub floor and extend across the sides of a floor opening in spaced relationship to the swing diameter of the first set of hammers to form a gap therebetween.