Patent GB-501879-A (GB)
Title: Improvements in aircraft
IPC: B64C1/00
Filed: 1938-05-23
Abstract: 501,879. Aircraft with resilient wing mounting. ROUANET, R. L. M. F., and REY, F. V. A. J. May 23, 1938, Nos. 15337 and 15338. Convention dates, May 24, 1937 and May 9, 1938. [Class 4] An aircraft comprises a body with two supporting wings adapted to pivot with respect to the body about rearwardly convergent axes under the control of springs and, if desired, of shock-absorbing means in such manner that increase of wing loading produces a rotation of the wing in the sense resulting in a reduction of the angle of incidence thereof. The wings may be coupled for dependent movement in order to ensure lateral balance and may be non- automatically rotated for lateral control. Means may also be provided for varying the mean dihedral angle. In one form, Fig. 2, wings 1, 2 are hinged to body 3 on shafts 4, 5 respectively, of which the axes XX<1>, YY<1> arc obliquely disposed. The wings are provided at their roots with pyramidal lever structures 7, 8 to the apices of which are connected resilient struts 11, 12, secured at opposite ends of a transverse balance lever 15 pivoted on an axle 16 which may be adjustably secured in body 3. Struts 11, 12 are connected to the levers at either end by ball-and-socket joints, and incorporate damping devices. pilot, may have means for rotating lever 15 to effect lateral control. The aerodynamic characteristics of the aeroplane may be varied by varying the characteristics of the springs or by adjusting axle 16 in the direction VV<1>. In Fig. 3, wing 1 is shown movable about a virtual axis X-X<1> obtained by pivoting the wing about a fore-and-aft axis TT<1> to a member 21 rotatably mounted about a lateral axis UU<1> and by the provision of a constraining link 25 connecting lever 7 to a fixed point 26 in the body. Resilient device 11 is socketed at 23 in arm 20 of member 2 1. The pivot axes XX<1> may be arranged to intersect the body at a point within the wing chord in which case the root part of the wing may be cut away at 31, Fig. 4, or made flexible. The pivots may be outboard as shown in Fig. 6, or two spaced sets of pivots may be provided for each wing, Fig. 15. Where an engine is mounted on the pivoting portion of a wing, the direction of rotation is such that the counter-torque tends to depress the wing tip whereby the effect of engine failure or reduction of torque is to reduce the incidence of the wing and hence the drag thereof. Simultaneously, owing to the action of the balance lever, the incidence of the other wing will be increased and the dissymmetry of twist to some extent counteracted by a dissymmetry of drag. Several modified arrangements of balance lever and spring means are described differing only in the disposition of the parts in the body and in the number of resilient elements used. The balance lever may be substituted by an equivalent hydraulic arrangement. In Fig. 12, levers 7, 8 are connected to elastic damping devices of the fluid type 11, 12 which are independently pivoted to the body at 44, 45. The cylinders of devices 11, 12 are interconnected by one or more conduits 46 which serve to balance the pressures in the two devices. A cock 47 may give variable throttling or if closed make the wings move independently. Similarly, the balance lever may be replaced by a pair of fluid pumps using an incompressible fluid and working in series with the elastic devices and connected by conduits such as 46. Springs of plate @or coil type, elastic cords rubber washers, fluid springs acting either in flexure, torsion, tension or compression may be employed and any type of shock-absorber of fluid or friction type. The elastic devices may consist of torsion rods such as 48, Fig. 14, which is pinned to wing 1 at 50 and to a lever 52 connected by a link 53 with a corresponding lever on the torsion rod of the other wing. A damping device 54 is arranged between a fixed point 56 and a lever 55 on wing 1. The above arrangement may be employed where the hinge axis of the wing is some -distance from the body, in which case the damping device, if fitted, is also within the wing and may be connected indirectly to member 55 through a bell-crank lever. The elastic devices in the arrangement of Fig. 15 may be similar to those of Fig. 12 and the conduits interconnecting the two pairs of cylinders may be independently controlled by cocks to render the movements of either the inner or outer wing panels, or both, independent of those on the other side of the craft. The elastic fluid damping devices with the fluid balance conduit may serve as bracing members where applied to non-cantilever types of aeroplane and applications are described to high and low wing monoplanes, to a sesquiplane and to a biplane, Fig. 20, in which the upper wings pivot about axes XX<1>, YY<1> and the lower about axes X<4>X<5>, Y<4>Y<5>.