An apparatus (10) comprising a pair of associated chopper drums (20), including a top chopper drum (21) and a lower chopper drum (22). The chopper drum (20) defines an axial cylindrical bore (25) having a rotational axis (26) into which is mounted a drive shaft (not shown) that is keyed radially to drive the chopper drum (20). Radially spaced from the rotational axis (26) are a plurality of outwardly facing recesses (30) defined by walls of a body of the chopper drum (20). Each recess (30) extends longitudinally along the periphery of the chopper drum end-end to provide a recess for mounting a corresponding plurality of cutting blades (35). Each recess is defined by a longitudinally extending lower wall (31) and an opposed and circumferentially spaced. The cross sectional profile of the chopper drum (20) is generally consistent throughout its length and includes a plurality of ridges (26) and troughs (27) with the ridges (26) built up to define therein the recesses 30, the ridges (24) being interposed by the troughs (27). A higher side wall (32) provides support for the cutting blade (35) and is inclined relative to a plane (36) extending radially outwardly from the rotational axis (26). The opposed smaller side wall (31) supports a wedge clamp (40).Linvention concerne un appareil (10) comprenant une paire de tambours hacheurs associés (20), incluant un tambour hacheur supérieur (21) et un tambour hacheur inférieur (22). Le tambour hacheur (20) définit un alésage cylindrique axial (25) pourvu dun axe de rotation (26) dans lequel est monté un arbre dentraînement (non illustré) qui est claveté radialement pour entraîner le tambour hacheur (20). Une pluralité dévidements orientés vers lextérieur (30), définis par des parois dun corps du tambour hacheur (20), sont espacés radialement de laxe de rotation (26). Chaque évidement (30) sétend longitudinalement le long de la périphérie dextrémité à extrémité du tambour hacheur de façon à former un évidement pour le montage du
