| 摘要 |
1469748 Extruding coatings on to cores GENERAL ENG CO (RADCLIFFE) Ltd 11 March 1974 [10 March 1973] 11672/73 Heading B5A In order to overcome the inconsistency in the output rate of an extruder 20 coating cords, cables or wires 26, a positive displacement device, e.g. 24 a gear pump, multi-screw pump is positioned between each die 25 and the extruder 20 to ensure a constant supply of material for coating the wires 26. A pre-determined pressure may be maintained at the inlet to each device 25 by either driving the extruder 20 at a faster rate than the devices 24 or by employing a pressure responsive device P, P<SP>1</SP> or P<SP>11</SP> between the devices 24 and the extruder 20. The coated wire is cooled set or cured in a region S before it reaches one or more (Fig. 2) haul-up devices 28. The latter incorporates twisting, bunching, or laying-up means 29, 30 for forming a cable from individual coated wires. A sheathing die may be provided. More than one layer of coating material may be applied at least partly around a single wire (Fig. 3). Various elements, e.g. extruder, haul-up and device(s) 24 may be presynchronized with each other by a single variable speed mechanical linkage DG, synchronous motors or positive displacement hydraulic motors. The coating material may comprise a vinyl, an amide, a polyolefin or a natural or synthetic rubber. |
