Abstract: A centrifugal drum apparatus for finishing the surfaces of metal objects is disclosed, including a housing, a disk-shaped rotor member connected with the housing for rotation about a generally horizontal axis, and a plurality of finishing drums open at one end and having longitudinal axes arranged symmetrically about and parallel with the rotor axis, the finishing drums being rotatably connected with the rotor member. The apparatus includes a first drive assembly for rotating the rotor member about the horizontal axis, and a second drive assembly for rotating the finishing drums about their longitudinal axes. When metal objects are placed within the finishing drums and the rotor member and finishing drums are rotated, the surfaces of the metal objects are ground and polished through abrasion with the inner surface of the drums.

Abstract: Apparatus for grinding and polishing small parts which is of the centrifugal drum polisher type, said apparatus including a stationary support, a rotor mounted on the support, and a plurality of drum containers mounted on the rotor and in frictional engagement with the stationary support so that the drum containers will rotate in response to rotation of the rotor.

Abstract: Drum polishing and tumbling apparatus having a cylindrical casing rotated about its central axis. A screw conveyor is located within the casing substantially from one end to the other. The screw conveyor is rotated about its axis relative to the casing. The screw conveyor extends radially outward into proximity to the surface of the inner wall of the casing. Seal means is provided if desired between the blade of the screw conveyor and the surface of the casing. The screw conveyor is journaled in bearings located in the end walls of the cylinder and is independently and selectively rotated.