Debarking mechanism

A debarking mechanism for the decortication or pretreatment of logs for separately performed final debarking and for the discharge of at least some of the bark removed from a wood stream passing through the debarking mechanism, the debarking mechanism comprising a number of rotatable debarking shafts extending parallel to the advancing direction (A) of the logs to be fed therethrough and provided with a number of teeth extending beyond the circumferential surface of the shaft and arranged to strip bark off the logs being processed, transversely to the longitudinal direction of the logs, and at the same time to convey the logs transversely relative to the shafts, the shafts being, together with the teeth thereof, arranged to form at least a part of a support surface on which the logs being processed travel through the debarking mechanism, and the debarking shafts being arranged relative to each other in such a way that the logs being processed perform a rotary motion (C) in the debarking mechanism, in which motion the logs on the support surface formed by the debarking shafts are forced in their turn, by the effect of the rotary motion of the debarking shafts, into the upper position, from which they roll down into the lower position on top of the other logs in the debarking mechanism, wherein the debarking shafts forming the part of the support surface for the logs, at least the uppermost debarking shaft has been moved sideways towards the inner part of the debarking mechanism in such a way that the debarking shaft directs an impact effect on logs colliding with it and moved by the debarking shafts located in a lower position, due to the effect of which the direction of movement of the logs having collided with the debarking shaft will change in such a way that, when dividing the movement into a horizontal and a vertical component, the horizontal component will point towards the inner part of the debarking mechanism, that the circumferential speed of the debarking shaft is selected to be the greater the higher the debarking shaft is positioned, and that a free passage is arranged for the bark passing over the uppermost debarking shaft, along which the bark is discharged from the debarking mechanism.