GB1253375A - Improvements in faired cable - Google Patents

Abstract

1,253,375. Cable. UNIROYAL Inc. 20 Nov., 1968 [22 Nov., 1967 (2)], No. 55132/68. Heading H1A. [Also in Divisions D1-D2] A faired electrical cable comprises an electrical conductor in a U-shaped strength member 38, Fig. 2, the member 38 being bridged by a tail member 39 having a higher flexibility than the strength member 38, the strength member 38 being so designed that its shear centre is in the immediate vicinity of the leading edge of the cable and at a considerably greater distance forward of the centre of pressure of the cable than is the centroid of the strength member. By "shear centre" or its equivalent "centre of twist" is meant the intersection of the horizontal axis of symmetry (the neutral axis) of the crosssection of a beam with the line of action of a vertical load when-the latter is applied to the beam so as not to cause any twisting thereof. By "centre of pressure" is meant the point at which the resultant of the aerodynamic forces of lift and drag intersects the chord line of an airfoil, the chord line being the line connecting the leading edge of the airfoil cross-section to the trailing edge. The strength member 38 includes a power conductor 40 held in the U-shape by an insulation filling 41 and two signal conductors 43 held in grooves formed in the tips of the arms of the U-shape. The strength member 38 comprises a multiplicity of substantially parallel, high modulus, longitudinally extending, continuous filaments 38<SP>1</SP> embedded in a resin binder. The tail member 39 comprises a resin matrix having a filler material of lower specific gravity than the resin matrix, for example glass microspheres 39<SP>1</SP>. The filaments 38<SP>1</SP> may be of glass or metal. Manufacture of the faired cable.-The cable may be made in an apparatus through which it passes in a step-by-step motion. In Figs. 6 and 7 continuous filaments 45 are impregnated with a resin, binder 49, surplus binder falling into a tray 53. A roll 48 presses the resultant mass into a U-shaped groove formed in the periphery of a roll 47 to provide an initially shaped bundle 45b, said bundle then passing through spaced rolls 54, Figs. 6 and 10, that change the bundle to one of more elongated shape as at 45d. The impregnated bundle 45d then enters a channel 55 of a lower mould member 56; Figs. (i and 10, of a curing press 57, into which channel 55 an upper mould member 58 can descend to close the mould. Prior to the mould being closed, a squeezing roller 60 travels reciprocally along the channel 55 to squeeze out excess resin and effect a preliminary compaction of the filament bundle. The mould members 56, 58 have heating means that may be electric heating elements or hot fluid conduits. When the curing is complete the resulting strength member 38 is passed into a guide trough 65 to cool. A first carriage 66, Fig. 16, carries a large central sanding wheel 78 flanked by two small sanding wheels (76), Fig. 17 (not shown). The wheel 78 cuts a central groove for the power conductor 40 and the wheels (76) cut grooves for the signal conductors 43. The carriage 66 may move along the strength member 38 or the strength member 38 may be pulled past the carriage 66. When the grooved strength member 38 eventually moves on a further step it passes under frame 79, Figs. 6 and 16, that lays the power and signal conductors 40, 43 in their respective grooves; and then under spouts 84, Fig. 6, from which resin for the insulation covering of the conductors is deposited. At the next stage the strength member 38 enters a curing press comprising upper and lower parts 86, 87, Fig. 6. In this press the insulation injected or deposited by the spouts 84 is cured. To form the tail member 39 the strength member 38 is then passed into a press 90, Figs. 6 and 24, comprising a lower mould member 91 for the strength member, designated 45k in Fig. 24, and an upper split mould member composed of two sections 93 and 94 that define the shape of the tail member 39. A resin mass 102 is injected by nozzles 101 into the press 90 before it closes and this mass is then compressed and cured in the press. When the finished cable leaves the press 90 grinding-wheels remove flash and the cable passes between a pair of endless belts 106, Fig. 6, that pull the cable through the apparatus. The cable is then wound up on a drum.