GB249542A - Improvements in or relating to envelopes for aircraft - Google Patents

Abstract

249,542. L³bbecke, W. March 21, 1925, [Convention date]. Acrostats; planes, construction of; parachutes. -An envelope of variable form for rigid and non- rigid balloons, aircraft planes and parachutes is composed of a number of triangular or quadrangular pieces of fabric, netting, &c. having intersecting threads, joined together in such a manner and so disposed that variations of the relative angles of the strands of the material may take place under stresses in certain directions and thereby change the shape of the envelope as a whole. Pieces of fabric mav be cut and set so that one or both sets of intersecting threads is or are parallel to one or two sides, of a triangle, which sides would then be indeformable in length, or the threads may be set in other predetermined directions to limit deformation in one direction, or specially woven net which may have knotted intersections may be used. The edges of the pieces are strengthened by sewn on bands. To control the variation of shape, pieces of indeformable shape may be introduced where necessary. A. balloon is described capable of varying from a prolate to an oblate spheroid as the gas expands or contracts and the load is carried bv an external netting having diagonal connections across the meshes, different diagonals becoming stressed as the balloon changes in shape. The load may be transferred to an internal suspension arranged parachutewise on the upper inner part of the balloon, the balloon then being assisted to assume the spherical and finally the oblate form. Should the balloon collapse it forms a parachute. The fabric or net may be proofed or provided with plates O or strips to form overlapping scales as shown in Figs. 10 and 11, as applied to deformable planes of an aeroplane. The planes can be moved as shown independently on the two sides of the machine. The fabric mav be of interwoven metal strips or plain or twilled fabric of cotton linen, silk, straw, wood, hair, rubber or wire. The displaceabde quadrangles allow movements similar to those of a fish during flight by alternately exerting a pull on one or the other side of the balloon envelope. The expansion of the sections in the directions not parallel to the threads may be limited by bands of fabric leather or perforated sheet metal, for example at the nose of an airship. In the case of a parachute the unalterable sides of the fabric sections are made tension and compression members and their nodal points connected by rods in one or more rings to a central vertical rod, the stretch of the quadrangles when in tension corresponding to the lengths of the rods extending from the rings.