Abstract: A tub grinder for grinding animal feed and the like of the type having a hammer mill extending below a stationary floor about which a tub side wall rotates, incorporates a rear discharge opening formed in a rear side wall of the hammer mill and includes deflector plates extending across an end wall of the grinder for directing material out the discharge opening to the rear of the tub grinder. Shear plates are adjustably secured to an end wall of the hammer mill housing. The shear plates are oriented in overlapping and angled relationship with respect to one another and to prevent ground materials from accumulating on the shear plates particularly when wet. Sickle blades are retractably positioned in the mill side walls for providing additional cutting action. Further, hammer assemblies are modified to include a knife edge and a face plate.

Abstract: A tub grinder suitable for comminuting forage crops as feed for livestock comprising a rotating circular tub having a floor with an opening therein through which a hammermill communicates for chopping the forage. When the forage is fed too quickly and overloads the hammermill, a governor senses that the rotational speed of the hammermill has been reduced and operatively signals the tub driving mechanism to slow the speed thereof, thus feeding forage at a lesser rate and allowing the hammermill to recover. A similar but opposite process occurs when the hammermill increases in speed to the extent that it is able to handle additional forage. A dampening mechanism is used in conjunction with the governor and functions to allow the tub rotation to slow immediately upon the hammermill being overloaded, but somewhat delays the increase of the tub rotation when the hammermill can receive additional forage.