Mill box for materials grinder

A grinding device, comprising:

• a frame;
• a grinding drum rotatably coupled to the frame;
• a curved sizing screen at least partially located beneath the grinding drum;
• a top cover supported by the frame, the top cover being moveable between a closed position and an open position;
• and
• a retainer carried by the top cover, the retainer being arranged to hold the curved sizing screen in position relative to the grinding drum when the top cover is in the closed position;
• wherein the sizing screen is removable from the frame by moving the top cover to the open position and lifting the sizing screen above the grinding drum.

A method of removing a sizing screen from a mill box, the sizing screen being at least partially located beneath a rotating drum mounted within the mill box, the method comprising the steps of:

• a) pivoting a top cover from a closed position to an open position;
• b) lifting the sizing screen in an upward direction such that that sizing screen slides along arcuate supports located within the mill box;
• and
• c) rotating the sizing screen around a centerline of the grinding drum.