| 摘要 |
<p>PURPOSE:To form a frame having deep outer peripheral recessed parts as a combination of two sheets of curved flat plates and to easily form the frame by molding this frame and subjecting the frame having the outer peripheral recessed parts to bridging and extending. CONSTITUTION:Two sheets of slender coordinate flat plates 1 having a concentrical cut piece shape are prepd. and their edges are so coupled as to be openable and closable. A V-shaped hinge frame cut piece 2 opening to an outer V shape is formed when force is applied at both ends so as to increase curvature. The curvature of this V-shaped hinge frame cut piece 2 increases and simultaneously its V angle increases if the force is applied to the cut piece so as to press its one end and, therefore, the simultaneous increase of the curvature and the V angle leads to an increase of the basic length of guts if the V-shaped hinge frame cut piece 2 is so deviced as to slightly increase its length. The tension is consequently increased if the length of the guts is assumed not to change. The tension of the guts are thus freely adjustable in the tensed state. The V-shaped hinge frame and V-frames, the sections of which are not pipes, are easily moldable '' as the frames are planar as a whole.</p> |
