Abstract: A preheater and feeder for thermoplastifiable material supplied to an extruder for synthetic resin has the counterrotating worms in a heated housing delivering the material at a rate determined by the worm speeds. The worms are hollow and the major portion of the heat, apart from friction heat, contributed to the material is delivered by passing a heating fluid through the hollow worms.

Abstract: Two worms of a worm extruder are connected to drive shafts of different lengths journaled in a transmission housing. For driving one of the worms, a first gear is keyed to the longer drive shaft and is driven by the motor gear and the electric motor. The second worm is driven by a further shaft, one end of which has a gear meshing with the second gear keyed to the short drive shaft so that the gear of this further shaft and the gears of the two drive shafts lie in a common plane. The further shaft is driven by a gear meshing with the motor shaft or by a separate motor. With this apparatus torque distribution is improved and the number of gears and components of the transmission is reduced.