Apparatus foe manufacturing tubes

Claim 1

IN APPARATUS FOR MANUFACTURING TUBES OF THERMOPLASTIC MATERIAL, RUBBER AND THE LIKE HAVING ONE OR MORE LAYERS OF REINFORCING THREADS HELICALLY WOUND AND EMBEDDED THEREIN, THE COMBINATION COMPRISING AN EXTRUSION PRESS, AN EXTRUSION DIE, MEANS DEFINING A CIRCULAR CHAMBER THROUGH WHICH THE PRESS COMMUNICATES WITH THE DIE, A PLURALITY OF CONCENTRIC BUSHES COAXIAL WITH THE CHAMBER, MEANS FOR INDEPENDENTLY ROTATING THE BUSHES, AT LEAST ON SPOOL CARRYING THE REINFORCING THREAD CONNECTED TO EACH BUSH FOR ROTATION THEREWITH ABOUT THE CHAMBER AXIS, EACH BUSH BEING PROVIDED WITH AT LEAST ONE RADIAL PASSAGE RECEIVING MATERIAL DELIVERED BY THE PRESS TO THE CHAMBER AND AT LEAST ONE LONGITUDINAL PASSAGE RECEIVING THREAD FROM THE SPOOL AND DELIVERING IT TO THE DIE SIDE OF THE BUSH, AND AN ANNULAR GROOVE IN THE OPPOSED SURFACES OF EACH OF THE BUSHES DEFINING A CHAMBER BETWEEN EACH PAIR OF BUSHES COMMUNICATING WITH THE RADIAL PASSAGES THEREBY TO PERMIT FLOW OF MATERIAL FROM THE PRESS THROUGH THE BUSHES TO THE DIE.