GB1537043A - Pressure hoses - Google Patents

Abstract

1537043 Pressure hoses STANDARD TELEPHONES & CABLES Ltd 22 Jan 1976 [27 Feb 1975] 8246/75 Heading F2P In making a flexible hose at least one layer A of helically coiled strip material of generally stepped, S-shaped cross-section having a first portion 2 overlapping a portion 1 of the adjacent strip (more than one strip may be used) with a layer of resilient sealing means therebetween and strain members 8 wound thereon. The strips are formed with grooves 3, 4 into which is applied the resilient sealing means (e.g. neoprene). Each surface of portions 1 and 2 may be coated with a layer of unsintered P.T.F.E. acting as an antifriction material 5, 6 and as an additional seal. A second layer B similar to layer A but of opposite hand may be wound on to layer A with an intermediate layer 7 of P.T.F.E. An interlocking braid 9 may be formed around layer 8 and a jacket 10 of polyurethane may be extruded over this to permeate the interstices of the braid 9. In a further embodiment (Fig. 3, not shown) a polyethylene glycol terephthalate (PGT) tube (11) is extruded, a metal strip (12) of stepped cross-section is wound on to tube (11), a second PGT sheath (13) is extruded over strip (12) and a strip (14), similar to (12) but of opposite hand, is wound over this followed by a third PGT tube (15). A large number of galvanized steel wires (16) are wound on followed by a further layer of wires (17) of opposite hand followed by a first sheath (18) of PGT. A tube (19) (e.g. of copper) may form a lining for the tube. The helically coiled strips may be made of steel or aluminium alloy.