| abstract |
1305198 Reinforced moulded structures NATIONAL RESEARCH DEVELOPMENT CORP 11 Nov 1970 [24 Oct 1969 11 Nov 1969 16 July 1970] 52192/69 20042/70 and 34569/70 Heading B5A [Also in Divisions B7 B8 D1 F2 and G1] A structural element which may constitute a reinforcement for moulded structures is made from a rope comprising a core 4 of continuous fibre impregnated with a curable matrix material (e.g. epoxy, polyester, furane, resorcinol- or phenol-formaldehyde resins, Friedel-Crafts resins, polyimides or UV catalysed methyl methacrylate) and a sheath 3 of deformable open-work construction (e.g. braided) which, when elongated, compacts the core and causes some of the matrix material to be squeezed out through the sheath. The sheath 3 may be of glass or carbon fibre, and the core 4 of carbon fibre, and the sheath may be separately formed and placed over the core before elongation. Curing the matrix material results in a rigid element, which, if placed over a former prior to curing (Fig. 3, not shown), may be of a desired shape and cross-section. To produce a pipe or hollow element (Fig. 4), a removable or permanent tube 9 may be incorporated in the core as a former. Various reinforced structures, including geodetic frameworks, may be formed by laying the rope-like element under tension around a former, e.g. of wood, polyurethane foam, or dissolvable material and then curing it, the former either being removed or retained. A crane jib (Fig. 5) is manufactured by winding the uncured rope-like element 12 in grooves of a wooden core 11, under tension (thus elongating the sheath), curing the structure, and laying a skin 13 of resin-impregnated glassfibre cloth thereon. A frame for a micrometer screw gauge (Fig. 8) is manufactured by winding the uncured rope-like element 17 in grooves of a wooden former 16, under tension (thus elongating the sheath), curing the structure, and covering it with a skin 18 of resin-impregnated glass-fibre cloth. A boat hull (Fig. 9) is constructed by winding the uncured rope-like element over pegs 23 on a removable wooden mould 20 (Fig. 10), any slack being taken up by final windings along longitudinal grooves 21 and beneath the gunwales 22. The element is then cured, the former removed, and an outer skin 19 of resin-impregnated glassfibre cloth is applied. Boat hulls may alternatively be constructed by laying a net, made of the uncured rope, over the former, tightening the net by windings along grooves 21 and beneath the gunwales 22, and curing as before. |