| 摘要 |
1414035 Flexible hose H VOHRER 12 Dec 1973 [14 Dec 1972] 57643/73 Heading F2P A flexible hose includes an inner hose wall 1, an outer hose wall 4, a supporting helix 2 which is situated in a helical cavity formed between the inner and outer hose walls 1, 4 and which is free to move in the cavity, and a strip 3 of relatively hard material wound between the turns of the helix 2 and parallel to it, the inner hose wall 1, strip 3 and outer hose wall 4 being united with one another. The hose may also include longitudinal reinforcing strips 6 applied directly to the inner hose wall 1 or arranged in undulating fashion under the strip 3 and over the helix 2 as shown in Fig. 5. The inner and outer walls 1, 4 may be made of soft P.V.C., and the helix 2 may be made of wire, or a rigid plastics material that does not adhere to the inner and outer walls, e.g. a polyamide or a polyolefine. The strip 3 may be made of hard P.V.C., strong cardboard, a woven or plaited textile band or a metal, e.g. aluminium or brass and may be bonded to the walls 1, 4 by welding, fusing or adhesive. The longitudinal strips 6, which completely surround the hose, may be made of P.V.C. strips reinforced with textile yarns or threads. The hose may be made by the apparatus shown in Fig. 6 in which the inner hose wall 1 is extruded on to a mandrel 7 by an extrusion head 8. The helix 2 is then applied at a winding station 9, the strips 6 are applied at station 10 and the strip 3 is applied at winding station 11. The nose then passes through a heating duct 12 and the outer hose wall 4 is applied by an extrusion head 13. The hose then passes through a cooling zone 15 and a pair of extractor rolls 16. |
