GB748395A - Improvements in or relating to strengthened reinforced structures - Google Patents

Abstract

748,395. Boats. LASZLO, P. D. DE. Sept. 16, 1953 [June 17, 1952; Dec. 18, 1952], Nos. 15236/52 and 32238/52. Class 113. [Also in Group VIII] A strengthened reinforced structure suitable for boat hulls is constructed by coating at least one layer of reinforcing material with a synthetic resin, the said structure having a rib-like strengthening on it, the rib being also made of reinforcing material and synthetic resin and being formed over a former consisting of a series of substantially independent elements joined together so as to provide a flexible composite elongated former over which further reinforcing material is laid, said composite former having flexibility to follow the curve of a surface but presenting appreciable rigidity in the direction perpendicular to the surface. A double-skin construction may be obtained by bridging the tops of the ribs with further reinforcing material. As shown (Fig. 1) a mould is covered with sheets of glass fibre reinforcing material 10, 11 permeated with a synthetic resin which may be cold-curing, and layers 12, 13 of the same material are laid over a V-section channel former 14 to provide the rib-like strengthening member. The former may be of sheet aluminium, polythene or of leatheroid, bent to form inclined sides 14a, 14b (Fig. 2), a flat top 14c, and inturned feet 14d. The channel so formed is slit at 14e at regular intervals to form short lengths: the slits are relatively wide and include the feet 14d but not the top 14c which is continuous. If desired, the former may be made of individual synthetic resin mouldings or light alloy castings secured along the top by adhesive tape or joined by passing nylon thread through registering holes in each casting. When the former is made of a material to which the resin on the reinforcing material will not adhere (such as polystyrene) it may be withdrawn. Sheets 12 and 13 cover not only the former but at least part of the first layers exposed between the formers. Fig. 4 shows a double-skin construction. The base layer 20 is laid on the mould and a series of formers 21, 22, 23, 24 laid at intervals upon it. One more or less continuous sheet 25 of the fabric is laid over all the formers, and resin applied thereto. The vertices of the formers are bridged by further sheets of reinforcing material: sheet 26 bridges formers 23, 24 and extends down those sides further from each other, terminating on the base layer. The layer 27 starts at the top of 24, bridges 23 and 22 and extends down the further side of 22 to terminate on 25. Similarly the next sheet starts at the top of 23, bridges 22 and 21 and extends down the further side of 21 on to layer 25. On completing the assembly, the resin is cured.