Patent ID: 6484770
Filing Date: 2002-11-26
Classification: B27L

Abstract:
A method of chipping wood comprising:providing a disc chipper having a plurality of knives; forming wood chips with the disc chipper by separating chips from a log; passing the wood chips through a chip opening in the disc such that the wood chips hit an impact surface located after one of the plurality of knives, wherein the direction of the impact surface deviates from the direction of a rear surface of said one of the plurality of knives so that the wood chips split into smaller pieces and separate from each other, and creating a stronger impact effect in proximity to the center of the disc than in than in proximity to the outer periphery of the disc in order to produce chips of uniform quality along all portions of said one of the plurality of knives, wherein the stronger impact effect is created by at least one of (i) making the chips hit the impact surface, wherein the direction of the impact surface in proximity to the center of the disc deviates more from the direction of the rear surface of the knife than in proximity to the outer periphery of the disc, and (ii) making the chips, before they hit the impact surface, pass further behind the rear surface of the knife in proximity to the outer periphery of the disc than in proximity to the center of the disc.