Abstract: The invention relates to a self-feeding wood chunker having cutting instruments (1, 2) rotating in opposite directions but with the same speed, which have, on surfaces facing one another, at least one cutting blade (3.sub.1, 3.sub.2 and 4.sub.1, 4.sub.2), the blades being curved in the direction of rotation such that the leading part (3a, 4a) thereof is nearer to the periphery of the respective cutting instrument and that the trailing part (3a, 4a) thereof is nearer to the axis of rotation (1a, 2a) of the respective cutting instrument. According to the invention, the cutting instruments (1, 2) are arranged with the axes of rotation (1a, 1b) displaced a definite distance (B) from one another.

Abstract: A device for disintegration of wood material such as roundwood, tree-tops, branches, waste wood, etc to firewood of a suitable length, said device comprising cutting members for the disintegration. In order to reduce the energy need the invention device comprises two cutting members which rotate in opposite directions and are provided with knives on their insides, one of the two cutting members being arranged to actuate by its knife material fed between the two cutting members in one direction while the other cutting member is arranged to actuate by its knife the material in the opposite direction for cutting off the material between the knives of the two cutting members.

Abstract: A comminuting apparatus for reducing trees or portions thereof to particles of engineered length especially suitable for ring flaking for subsequent use in flakeboard fabrication and for use by utilities and industries using wood for energy production. The apparatus utilizes one or two rotating discs to which one on a plurality of curved cutting members are mounted and which severs trees, tree portions or other fibrous masses fed at right angles to a rotating shaft member. By the precise design of cutting members mounted on the rotating disc or discs, wood particles of engineered length are produced.

Abstract: A cutting machine to sever elongated wood particles or fiber masses to a predetermined length in one self-feeding and continuous operation. Said cutting machine reduces naturally formed and partially processed wood into particles of controlled length and cross-sectional dimension. A rotating spiral cutting edge mounted on a drive shaft is of varying radial length increasing from zero on one end to a radial length greater than the cross-sectional dimension of the wood or fiber to be sheared. In back of the shearing section a separate degradation spiral is situated that gradually decreases back to a minimal radial length on the other end. An anvil is provided over the length of the shearing section against which the rotating cutting edge shears the wood. In the back or degradation section, a casing in the shape of a truncated cone is fitted loosely around the decreasing spiral. Wood is fed parallel to the drive shaft into the front end of the apparatus.