| 摘要 |
Apparatus (2) for continuous extrusion of an aluminium sheathing (22) on to a core cable (8) includes a rotatable wheel formed with two identical circumferential grooves outwardly bounded by arcuate tooling discharging through radial exit apertures to an extrusion chamber positioned around a portal mandrel. A powered pay-off reel (10) is arranged continuously to supply the core cable (8) through the mandrel whilst the aluminium sheathing (22) is extruded as a loose fit from the extrusion chamber around the core cable (8). The extruded cable (22) is discharged through cooling means (24) to a roller cormgator (26) including a rotating frame mounted on a carriage (27) freely moveable axially of the cable (22) and provided with a rotational drive having a roller arranged to form a continuous helical indentation in the sheathing (22). Pneumatic actuating cylinders (32) are positioned on the carriage (27) to provide a constant, low magnitude, tension on the portion of the sheath (22) intermediate the extrusion chamber and the roller corrugator (26) and limit forces tending to distort the uncooled sheath. A pair of opposed grooved rollers (34) are provided upstream of the roller corrugator (26) to restrict transmission upstream of any torsional forces arising from the roller corrugator. The rotational speed of the rotating frame of the roller corrugator (26) is regulated in accordance with the linear speed of the cable (22) to effect transport of the cable without causing unacceptable stretching of the sheath. |
