Extrusion head for an extrusion installation for the rubber or plastic

Abstract

An extrusion head having a stationary part fixed on an extrusion installation having a plurality of extrusion cylinders supplying an extrudate formed from several components. The stationary part has extrudate flow channels each in communication with a respective extrusion cylinder and a common extrusion die. Two pivotable outer parts pivotally hinged on the stationary part are selectively swingable individually between open and closed positions by respective piston-cylinder units. The two outer parts define an extrusion orifice for the die in their closed position. A pair of locking piston-cylinders provided with hammerhead piston rods hold the respective outer parts clamped against the stationary during an extrusion. Actuator piston-cylinder units selectively swing the piston rods of the locking piston-cylinder units clear of the outer parts for opening them for cleaning extrudate channels or for an extrusion die change. Two pivotable inner parts between the outer parts and the stationary part define extrudate channels jointly with outer parts and stationary part and are selectively swingable by a respective piston-cylinder unit and exposing corresponding flow channels of the stationary part for cleaning when the outer parts are open. The inner parts have lateral flanges with a respective recess into which is inserted a retainer piston rod of a corresponding piston-cylinder unit to retain the respective inner part closing a respective stationary part flow channel against residual extrudate in the absence of extrusion of extrudate therethrough.