| 摘要 |
1,194,473. Extruding cable sheaths. PIRELLI S.p.A. 28 Feb., 1968 [24 April, 1967], No. 9555/68. Heading B3P. [Also in Divisions H1, and B4-B5] Apparatus for sheathing liquid (e.g. oil) impregnated electric cables with, e.g. lead or aluminium comprises extrusion means including an inner die member 10 having a bore lined by a metal tube 12 which is surrounded by a thermally insulating material 13 extending from the extruding opening of the duct 11 to a thermally insulated packing ring 17. The ring 17 is axially compressed against an annular shoulder 16 at an intermediate portion in the bore of the inner die member to provide a fluid-tight seal between the internal surface of the bore and the cable to be sheathed by the action of a slidable metal sleeve 18. This action is effected by a threaded ring 22 screwed against spring washers 20 which engage an annular ridge 21 on the sleeve 18 to press it against a flange 14 on the tube 12. The sleeve 18 is spaced from tube 12 by a thermally insulating layer 19. The packing ring 17 is constituted by an annular asbestos layer interposed between two copper rings. A cooling tube 6 is included which is held against the extruder head 7 by a screw-threaded clamping ring 9, a sealing gasket 8 being interposed between head 7 and tube 6. The sheath may be cooled by spraying with water under external pressure or vacuum conditions or at atmospheric pressure. |
