Barrel Washer.

Patent for a machine that cleans barrels. It has "barrel-supporting rollers to rotate the barrel in contact with brushes" (lines 13-15), which are more durable than rollers made from rubber tires. The rollers also each have an inner portion, a detachable annular exterior, and an elastic ring around the outside. Brushes are attached on opposite sides of the barrel, held up by a frame