GB360976A - Improvements in means for controlling aeroplanes - Google Patents

Abstract

360,976. Controlling aeroplanes. PAGE, F. H. and PAGE, Ltd., H., 40, Claremont Road, Cricklewood, London. Aug. 15, 1930, No. 24479. [Class 4.] Wings having ailerons pivoted to their trailing edges are provided with interceptors adapted, when brought into operation, to disturb the air flow over the upper surface of the wing, which interceptors are operable by the ailerons only when the wing approaches the stalling angle, or is stalled. In one form, Figs. 1, 3 and 4 an automatic slat 2 carried by links 4, 5 on the wing 1 is arranged to uncover an interceptor 11 when it moves forwardly at high angles of incidence. The interceptor 11 is pivotally mounted at 12 and is operated by a lever 13 pivoted at 141 on link 5, having a roller 14 on its upper end and connected at its lower end with one end of a cable 15 connected to aileron 3. The roller 14 is normally out of contact with the interceptor, and cable 15 is normally slack to allow of operation of the aileron but is rendered taut by forward movement of the slat and the links 4, 5, Fig. 3, which also brings roller 14 into contact with the interceptor, thereafter upward movement of the aileron causes rotation of lever 13 to raise the interceptor 11 against the resistance of a spring 16<11>. A spring 18 permits unimpeded movement of the aileron beyond that necessary fully to raise the interceptor, and a spring 16 maintains cable 15 in tension at all times in the neighbourhood of the lever and link mechanism of the slat. Fig. 5 shows an application to a wing have a slat mounted on a channel 21 movable in an arcuate path, the lever 13 being mounted on an arm 26 pivoted on the channel 21 and moving forwardly with it as the interceptor is uncovered. A roller 28 on arm 26 engages with a ramp 29 at the end of its travel and thereby rocks the arm 26 and lever 13 upwardly to bring roller 14 into operative position. In a further modification, Fig. 9, lever 13 is mounted on an extension 30 of a lever 31 pivoted co-axially with the link 4 and rotated on forward movement of the slat by means of a pin 33 on link 5 which engages in a slot formed at its upper end. This lever arrangement may be used with either of the constructions previously described. In a further modification the lever 13 is fixed to the wing and forward movement of the slat is utilized to take up slack in cable 15, a link carrying a pulley round which the cable is carried being interconnected with a moving part of the slat mounting. Fig. 12 shows an application of the intention to an unslotted wing, in which an incidence device consisting of a small pivoted aerofoil 40 statically balanced by a counterweight 42 is moved upwardly at large angles of incidence and serves to rotate a lever 45 having a pin 48 engaging in a slot 49 of a rocking lever carrying lever 44. Slot 49 is so shaped that the pin 48 locks the lever 44 at the end of its forward travel until freed again by downward movement of the aerofoil 40. According to a modification a small slat having no considerable slot action may be employed.