Pelletizer with cutting knife control

A pelletizer for pelletizing rubber or thermoplastic material discharged by a conveying screw from an extruder, comprising:

• a die plate mounted at a discharge end of the extruder outwardly of the conveying screw, said die plate having an outer face;
• a knife shaft mounted parallel to and spaced from the conveying screw, and drive means spaced rearwardly from said discharge end of said extruder for rotating said knife shaft;
• a stationary bearing for supporting said knife shaft adjacent said drive means, and a mobile bearing for supporting said knife shaft at an outer end thereof adjacent the discharge end of the extruder, means for heating and cooling said shaft to permit linear expansion and contraction of said shaft through said mobile bearing;
• a knife beam holder mounted on the outer end of said shaft for rotation with said shaft;
• a plurality of knife beams mounted in spaced relation on said knife beam holder, said knife beams carrying cutting knives which rotate closely adjacent and across the outer face of said die plate so as to cut the stands extruded through said die plate into short pieces or pellets, with the spacing of said cutting knives form the outer face of said die plate being controlled by the linear position of said shaft which is in turn controlled by said heating and cooling means.