Patent GB-512190-A (GB)
Title: Improvements in automatic stabilizing devices for aircraft
IPC: G05D1/00
Filed: 1938-07-22
Abstract: 512,190. Automatically stabilizing aircraft. ALKAN, R. July 22, 1938, No. 21786. Convention date, Aug. 12, 1937. [Class 135] A device for automatically stabilizing or piloting aircraft in response to amplitude of deviation, speed of deviation and acceleration of deviation about one or more of the three axes of stabilization comprises a control member displaced by a gyroscopic or equivalent means for defining the axis of reference, follow up means for said member operated by compressed air and operatively connected with a speed-multiplying gear causing movements of the follow-up means to be retarded proportionally to the speed and acceleration of deviation, totalizing means for controlling a servomotor proportionally to the deviation, speed and acceleration of deviation to operate a control surface of the aeroplane and is provided with auxiliary control means acting on a differential mechanism between the means defining the axis of reference and the member displaced thereby. In the form shown in the Figure a gyro-vertical 1 acts through a differential gear 6, 7, 9 on a spindle 8 carrying a control plate 11 adapted to control the operation of a pair of cylinders 16, 17 coupled by linkage 28-33 to an aileron 34. Follow-up means associated with the plate 11 are provided as described in Specification 491,920. A directional gyroscope 35 is adapted to operate a control plate associated with similar follow-up means said control plate being adapted to control a power device coupled to the vertical rudder. Manual adjustment of the setting of the gyroscope 35 is effected by a handwheel 54 acting through bevel and worm gearing and shafts 38, 40. The shaft 40 also carries a spur wheel 41 geared to an escapement wheel 43 which co-operates with a free anchor escapement 44 carried by a disc 46. A shaft on this disc carries a bevel pinion 47 meshing with a toothed sector 48 on the planet carrier 10. The carrier which is loaded by a spring 50 adapted to wrap round one of two cam surfaces 53 carries one or more planet pinions meshing with a sun-wheel 6 on a shaft coupled to the gyroscope and a sun-wheel 7 on a shaft 8 coupled to the control plate. It is stated the mechanism described permits each angle of the frame 10 to correspond with a definite speed of rotation of the shaft 40. In a modification the planet carrier is formed with an arm connected by a spring with a fixed point. In another form the planet carrier is moved by a gyroscopic turn indicator. In still another modification adapted to control the elevator two differential mechanisms are inserted between the gyroscope and the control plate. The planet carrier of one of these is moved by a barometric capsule adjustably loaded by a spring and coupled to the carrier by a lever working between adjustable stops. The other planet carrier is coupled to a similar lever coupled to a pair of bellows adjustably loaded by a spring and subject to the pressures of a Pitot tube or Venturi pipe arranged to give an indication of the air-speed of the craft. Specifications 441,439 and 475,321, [both in Group XX], also are referred to.