PURPOSE: To provide a mixing roller usable as either an oscillating or non- oscillating roller by providing a means to secure on a frame a transmission drive, which generates axial oscillatory movement, for side oscillation.

CONSTITUTION: The mixing roller 1 is driven by the friction of the roller body, and, when an engaging pin 27 is in engagement with a mating receptacle 29, a drive casing 18 is stationary. When a shaft 6 rotates at a revolution n2 which is different from the revolution n1 of the roller 1, it causes the roller 1 to make side oscillatory movement via side oscillation cams 37, 38 and cam rollers 41, 42 because of the difference between the revolution n1 and the revolution n2. Next, when a handle 31 is moved to the right side, the engaging pin 27' is engaged with a mating receptacle 29' of the gear 16. As the result, the roller 1, the transmission casing 18, and the shaft 6 makes rotation at the same revolution in ball bearing 7, 8. Accordingly, side oscillatory movement does not occur.