| 摘要 |
918,348. Non-metallic tubes. TECALEMIT Ltd. April 21,1959 [April 24, 1958], No. 13033/58. Class 99(2). [Also in Group V] In a -method of manufacturing flexible tubing having a core made of a synthetic plastic and an outer sheath made of a material which, after having been formed around the core, requires to be heat treated at a temperature which is liable to produce softening of, or damage to, the core material, the material for forming the sheath is extruded on to the core and the tubing formed is passed through a heating chamber while the interior of the core is being kept cooled by introducing into it a cooling fluid which absorbs sufficient heat from the core to prevent it from being damaged or deleteriously softened. The core may be made of a polyamide and may be surrounded by one or more layers of braided natural or synthetic filaments. The sheath may be of natural or synthetic rubber. As shown, a tubular core 7 is drawn from a supply reel 5 through an adhesive-applying device 8 and is passed through an extruder 10 where the sheath is applied on to the core. The tubing is then cured in a heating chamber 11 and is drawn from the latter by grooved rollers 12 and wound on a reel 13. The ends of the core 7 and of the tubing are respectively connected to the hollow shafts 14, 15 of the reels 5, 13. Cooling fluid from a refrigerated or cooling tank 18 is fed to the shaft 14 by a pump 19 and circulates through the tubing and through pipes 17, 22 back to the tank. The cooling fluid, which may be water, brine or a gas, may be under sufficient pressure to provide additional safeguard against the collapse of the core Alternatively, the core may be filled with a cooled liquid before it enters the heating chamber. Specification 918,349 is referred to.
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