Abstract: A retractable debarking block for a debarker having an enclosure to receive logs for debarking in order to vary the aggressiveness of the debarking process. The block member has a debarking surface with projecting teeth and is positionable within the enclosure of the debarker to be movable between a retracted position in which the debarking surface does not contact logs in the enclosure and an exposed position in which the debarking surface is exposed to engage logs. The block member is fittable into a rotor or drum type debarker. An actuator is provided to move the debarking surface between the retracted and exposed positions. The actuator is adapted to permit automatic movement of the debarking surface toward the retracted position if the force exerted by the logs exceeds a pre-set limit to prevent damage to the blocks and the logs. Preferably, the actuator is an airbag or telescoping cylinder operable over a range of pressures to permit adjustment of the pre-set limit.

Abstract: An apparatus for debarking logs comprising a drum rotatable about an axis and having an inner surface and outer surface with at least one movable debarking surface adjacent the inner surface of the drum to debark logs that come into contact with the movable debarking surface at a first rate. There is at least one fixed debarking surface at the inner surface of the drum to debark logs that come into contact with the fixed debarking surface at a second rate. The movable debarking surface is movable with respect to the inner surface of the drum between an operating position to allow contact between the movable debarking surface and the logs and a retracted position to minimize contact between the movable debarking surface and the logs.