Patent GB-331283-A (GB)
Title: Improvements in or relating to aircraft
IPC: B64C23/02
Filed: 1929-04-06
Abstract: 331,283. Thurston, A. P. April 6, 1929. Steering and balancing.-For delaying the stalling angle of a main plane or controlling surface, one or a number of movable riders is associated therewith in such a manner that when a certain angle of incidence of the plane is reached each rider moves continuously in a lifting direction in relation to the air passing over the plane or in a direction such as to deflect air on to the nose or other part of the plane surface. An aeroplane is described having a two bladed rider at the leading edge of the wing and of the tail plane on both sides of the machine. The blades 2 of the rider are carried by a spindle 5 journaled in a link 12, Fig. 2, pivoted to the plane and normally rest in contact with the curved forward surface of the plane parallel to the leading edge. When a critical angle is reached the rider first rises into the position shown in dotted lines and then commences automaticallv to rotate so as to increase the lift of the combination both directly and by delaying the breakdown of the streamline flow. A stop provided with a recess 53 engages a tooth 54 on the boss of the rider as it returns to its normal position, this tooth also preventing the rider from striking the plane until it has stopped rotating. The axis of the spindle 5 may be forwardly inclined 10 or 15 degrees to the perpendicular to the chord of the plane and this angle may diminish, increase, or remain constant as the rider rises. Fig. 3 shows a modification in which the rider spindle 5 is carried by a, bracket 55 on a link 16 which is connected to the plane by links 17, 18. A spring-loaded catch 56 on the link 17 engages a notch 57 on the boss 58 of the rider in its normal position. By varying the point of articulation of the links 17, 18 the inclination of the axis of the spindle 5 may be varied and this angle may decrease as the rider rises, as shown, or it may remain constant or increase. For locking the rider in its normal position, a sleeve 27, Fig. 4, having a helical edge 26 and a vertical slot 25 may be mounted on the link 16 to engage a pin 24 in the boss of the rider which slides on the spindle 5 against a light spring 29. Alternatively the slot 25 may be omitted and the pin 24 arranged to work in a helical slot cut in a cylindrical sleeve. Such a cylindrical sleeve may be mounted at a fixed angle on the plane instead of being mounted on links, the rider spindle passing right through it and a spring for resisting the rise of the rider being arranged below it. Fig. 6 shows a rider bearing mounted on links 34, 35 and provided with a roller 38 which rides over a track 39. Other modifications are described in which the rider spindle passes through a pivoted block and its lower end has a T-piece guided in slots in the plane, or it is connected to a link pivoted to the Plane. In the latter case the rider is normally nested over a slot through the plane. Fig. 9 shows a mounting which ensures that the rider moves downwards and forwards after it has lifted from the surface. The boss in which the spindle 5 rotates is carried by the link 61 and a positioning sleeve similar to that shown in Fig. 4 slides on the spindle and is connected to a link 69. In all cases the blades instead) of fitting the surface in a position parallel to the leading edge may fit it in an inclined position or they may have the usual formation of an airscrew. They may normally rest in the line of flight, and more than two blades may be used, for example four. Two superposed two bladed riders connected so that at rest they are parallel and when in motion at right angles to one another may be employed. Riders may be mounted towards the rear of the planes; there may be a central rider in place of or in addition to those described or additional riders may be placed nearer the wing tips. The blades may be hinged at the roots to move upwardly; they may also be hinged to increase their pitch angle as the rider moves from the plane. The position of the riders when not rotating or their speed of rotation may be controlled by varying the inclination of small planes pivoted to the blades or hubs. A governor may render the locking means inoperative if the speed of rotation exceeds a given amount and apply a brake or restore the looking means to operative position as the speed falls. The pilot may be provided with means for locking the rider in its open or closed position at will or a spring loaded vane as described in Specification 313,419 may be employed to prevent the riders from moving unless the flight speed is below the normal flying speed, or they may be locked or unlocked by a pendulum which releases the riders when the machine is at a dangerous angle. The rotation of the riders may be synchronized. According to the fourth Provisional Specification riders may be used in place of elevators, rudders, or ailerons, the provision for rising being omitted. A rider rotating about a swinging link is described passing through a slot in the plane, a one tooth ratchet device sliding on the spindle and being guided in inclined slots to engage a corresponding device on the rider when in its normal position. The fifth Provisional Specification describes a centrifugally controlled ratchet locking device and the sixth Provisional Specification describes a mounting similar to that of Fig. 3 but with the links extending forwardly from the rider and a looking ratchet controlled by a link.