Patent GB-422813-A (GB)
Title: Improvements in control apparatus for aeroplanes and other dirigible objects
IPC: G05D1/02
Filed: 1933-12-09
Abstract: 422,813. Controlling aircraft. MEREDITH, F. W., Royal Aircraft Establishment, South Farnborough, Hampshire, and COOKE, P. A., Air Ministry, Kingsway, London. Dec. 9, 1933, No. 34695. [Class 4] [See also Group XX] A gyroscopic control system for aeroplanes and other dirigible objects comprises (1) a pendulous gyroscope having its centre of gravity below the roll axis of the aeroplane, and comprising a frame 7, an outer gimbal ring 5 mounted to turn about the horizontal roll axis on the frame 7, an inner gimbal ring 3 mounted to turn about a normally vertical axis on the outer ring and a rotor 1 mounted in the ring 3 to rotate about a normally horizontal spin axis normal to the roll axis ; (2) means for operating ailerons in accordance with deviation of the ring 5 relative to the frame about the roll axis ; (3) means operable, when the ring 3 precesses from a normal position, relatively to the outer ring 5, to apply, between the outer ring 5 and the frame 7, a torque of a corresponding sign to the relative movement between the rings in a direction to produce a counter-precession of the inner ring and (4) restoring means for applying a torque between the rings 3, 5 when the inner ring precesses relatively to the outer ring in the opposite direction to the direction of precession. The movement of the gyroscope and the angular momentum of its rotor are so related to the forward velocity of the aeroplane, that the gyroscope will, when the aeroplane moves on a curved path, precess' in azimuth under the influence of centrifugal force at approximately the same angular velocity as the aeroplane is turning, to maintain the relative relationship between the gyroscope axis and the aeroplane. As shown, the frame 7 is pivoted in a frame 9 mounted on the aeroplane on the same roll axis as the ring 5 which carries a weight 10. (2) Relative movement between the ring 5 and the frame 7 operates due to relative movement between the gyroscope and aeroplane, through a link 21 connected to the ring 5, a piston valve 22 mounted on the frame 7 to supply compressed air to a servo-motor 27, which operates the ailerons. A lever 29 pivoted on the aeroplane and having a bifurcated end which engages the ring 7 and which is connected to the pistonrod 28 of the servo-motor provides a follow-up mechanism. (3) Relative movement between the rings 3, 5 operates through a link 14 connected to the ring 3 a piston valve 13 to cause a piston 18 mounted on the ring 5 and connected to the frame 7 by a link 19 to apply a torque reaction between the frame 7 and the ring 5 in such a sense as to oppose the gravity torque due to the pendulous weight to limit the relative azimuthal precession of the ring 3. (4) A spring 20 mounted on the ring 5 applies a restoring torque through the link 14 to the ring 3 to cause a precession of the ring 5 about its fore-and-aft roll axis and thus return the ring 5 and the weight 10 back to the vertical plane. The mechanism will cause an aeroplane to fly on a curved course without appreciable banking. The apparatus may be modified so that the aeroplane is banked to the appropriate extent in curved flight by providing a torque between the frame 7 and the ring 5 which is proportional to the angular velocity at which the aeroplane is turning.