| 摘要 |
544,137. Compound sheet materials. MERRON, A. C. Aug. 7, 1940, Nos. 12662 and 15554. [Class 140] [Also in Group XXIII] In making laminated panels or shells curved in two planes for use in the construction of boats &c. the material for each layer is so shaped by cutting before bending that it can be bent to the required curvature without buckling (i.e. it is subjected only to simple bending stresses) the pre-formed layers being subsequently assembled and secured together by an adhesive while under pressure. The layers are preferably of wood but some may be of metal, fabric or rubber. Layers of wood veneer are preferably arranged so that the grain in adjacent layers crosses at a substantial angle and the shaping is carried out so that the joints in adjacent layers are staggered. Both the pre-forming and the uniting pressure is preferably applied to the work, which is supported on a former, through a layer of sponge rubber, fluid (e.g. steam) pressure being applied through a flexible bag. One or more of the intermediate layers may consist of apertured materials, or of spaced strips. Specification 438,842, [Groug XXIII], is referred to. |
