GB430831A - Improvements relating to landing gear for aircraft - Google Patents

Abstract

430,831. Controlling aircraft automatically. NORTON, J. B., Marston Hall, near Grantham, Lincolnshire. Jan. 11, 1934, No. 1100. [Class 4] In landing-gear for aircraft in which an angularly movable feeler or ski is extended below the aircraft and on contact with the landing surface automatically causes the controls to be set into the correct position to flatten out the machine, the rate at which the controls are set is varied in accordance with the air speed of the aircraft on landing. When the machine is approaching the ground the manual operation of a lever 8 connected to a rod 25 removes a pivoted catch 27 from a loop 5 on the ski 4 which moves angularly towards the ground under the action of its weight and of a cable 30 attached to the lever 8 until laterally movable spring catches 23, 24 (Fig. 8) engage associated recesses in the undercarriage 3. A lever 9, Fig. 3, is moved forward and actuates a rod 46 to the right, putting tension on a spring 50 attached to a piston 49 in a hydraulic cylinder 51 until a catch 47 is latched by a pivoted nose 75 on a vertically movable latch member 72 so that the spring load on the control column 7 is not affected by the tension of the spring 50. When the aeroplane reaches the landing surface the toe 4A of the ski 4 pivots about its axis 4B and operates a cable 15, Fig. 7, which withdraws the spring catches 23, 24 from their recesses. The ski 4 moves upwards under the action of a spring 37 and actuates to the left the cable 30 and the rod 25. A projection 71 on the rod 25 engages a pivoted lever 81 of which the end 79 moves downwardly to release the projection 47 from the catch 75, allowing the rods 48, 46 controlling the column 7 to move to the left. The rate at which the control column is moved depends upon the flow of liquid from the cylinder 51 through a valve 54 controlled by the speed of the aircraft on approaching the ground. An auxiliary airscrew 68 is connected through a flywheel 69 and governor mechanism 67 to a piston 65 which through a further piston 60 rotates an arm connected to a quick-threaded spindle. 56 on which the valve 54 is mounted. The landing gear can be put out of action if the pilot decides to delay landing, by moving the levers 8, 9 in succession to release the catches 23, 24 and to move the stop 47 into the off position releasing the tension in the spring 50.