| 摘要 |
727,657. Compound sheet materials. GREEN, D. SALISBURY-. Oct. 10, 1952 [Oct. 17, 1951], No. 24270/51. Class 140. [Also in Group XXXIII] A boat hull or other article having an open hollow form is made by building up, on a mould shaped externally to the internal form of the article, layers of sheet material impregnated with a thermosetting synthetic resin, each layer comprising a small number of pieces each constituting a large fraction of the area of said layer and the said pieces being shaped to conform to surfaces having double curvature by notching them from the edges and bringing the sides of the notches together, applying a coating of thermosetting synthetic resinous adhesive to each inner layer of sheet material before the next outer layer is applied, and placing the mould with the sheet material thereon in an oven for a time sufficient to cure the impregnant and the adhesive, both the impregnant and the adhesive being capable of being cured at low temperature and pressure. The mould may be of wood, sheet metal, or of the same material as the hull to be moulded, suitably stiffened with battens, and coated with wax to prevent adhesion of the moulded hull. The pieces, which may be of resin-impregnated asbestos felt, are laid edge-to-edge without overlap except along the centre line 10 of the boat where chamfered joints are made in each layer. The joints in successive layers are offset. After curing, the portions of each layer projecting beyond the mould are trimmed off and wooden fittings such as a keel 11, gunwales 12, and a transom, are secured to the hull by copper fastenings. The boat is finally painted. |
