Abstract: A shredding apparatus includes rotating shredder rollers with parallel axes. Each roller is formed by numerous toothed discs with spaces between the discs. Two or more of the rollers are cooperating rollers with the discs of the cooperating rollers being offset so that the discs of each of the cooperating rollers can enter the spaces between the discs of another one of the cooperating rollers. Some of the rollers cooperate with curved grid sectors that are coaxial with the rollers. Curved, non-perforated and/or perforated plate sectors are coaxial with a pair of cooperating rollers rotating in opposite directions, the plate sectors being coaxial with and having a greater radius than the cooperating rollers and extending around the cooperating rollers for an arc. Blades are provided along one or more edges between the perforated and/or plate sectors.

Abstract: A shredder (1) is surrounded by a revolving screen (3) which also acts as an elevator. Said shredder outputs the shredded material in the interior of said screen (3), which allows the exit of the smaller material through the holes and lifts the remaining material depositing it once more at the input of the shredder (1). According to the present invention the bottom surface of the drum faces a fixed wall (8) placed at such a distance that it determines the third dimension of the material which passes through.