Patent GB-514995-A (GB)
Abstract: 514,995. Automatic control of aircraft. FLOREZ, L. DE. April 29, 1938, No. 12895. Convention date, April 30, 1937. [Class 135] [Also in Group XXXIII] In an automatic navigating apparatus, the amount of movement given to the rudder is dependent upon three quantities, the angular acceleration of the deviation, the rate of deviation and the extent of the deviation. The power cylinder 59 controlling the rudder is subjected to differences of pressure on opposite sides of its piston 60, which originate with a venturi tube 40 and are controlled by an oscillating valve 51. This valve is operated through the parts 53, 54 by a device 55 responsive to the angular acceleration of the deviation. The pressures in the cylinder 59 are applied to the diaphragm chambers 68, 69 which provide a pneumatic follow-up device. The diaphragms operate through rods 72 which are also connected to diaphragms in chambers 43, 44. These are subjected to the pressures resulting from a second oscillatory valve 25 under the control of a device 20 responsive to the rate of deviation and the total movement of the valve 51 is modified in accordance with these pressures. These pressures however are modified by the third quantity, the extent of the deviation. For this purpose the pipes 41, 42 connecting the valve 25 to the diaphragm chambers 43, 44 are also connected through throttling valves 47, 48 to reservoirs 45, 46. The pressure in these reservoirs rises throughout the extent of the deviation and when the pressure has been cut off by the valve 25 the fall in pressure is retarded by the escape of air from the reservoirs. Throttle valves 49, 50 and 76, 77 occur in the pressure pipes and a valved bye-pass 64 can throw the power cylinder out of action. But to permit the pilot to make sudden rudder adjustments without using the bye-pass, spring-closed relief valves 150, 151 are provided in the piston. A device 149 subjected to the pressures in the pipes 57, 58 indicates the value of the co-ordinated control. Fig. 6 shows the valve 51, the valve 25 being similar. The chamber 36a communicates with the atmosphere through an air filter and the chamber 38a is partially evacuated by the venturi tube 40. Ports 30a, 32a and 31a, 33a cooperate with a valve disc 26a to determine the pressures in the pipes 57, 58. Some part of the rudder movement may be communicated to the ailerons 90 through cables 81, a lever 83, an adjustable lost motion device provided by screws 85 on the lever 83 and an arm 86 on the aileron control shaft 84. The Specification as open to inspection under Sect. 91 comprises also the following subject - matter. Apparatus for maintaining proper lateral altitude in level flight and proper banking in turns includes the valve shown in Fig. 9 (Cancelled). A sliding valve 97 unites weighted diaphragms 94, 95 and controls the pressures in pipes 115, 116 leading to an aileron control cylinder and in passages 117, 118 communicating with the outsides of the diaphragms. Throttle valves are provided in the pipes 115, 116 and in a bye-pass pipe on the control cylinder. A valve is provided in the pipe from the venturi and one by which the venturi pipe may be opened to atmosphere. The valve may be positioned longitudinally of the aircraft and be used to secure proper longitudinal attitude. The action can be intensified by tilting the valve about a transverse axis by means of a bellows connected to a second venturi acting as a speed responsive device. Proper longitudinal attitude may also be maintained by an elevator control. cylinder 126, Fig. 11 (Cancelled), one side of which is evacuated in accordance with the air-speed by a venturi 40a. It operates against a force provided by a spring 129 and an adjustable lever 130. A throttle valve 123 and a valve 124 to atmosphere are provided. In a modification, a second power cylinder is applied to an intermediate point in the lever 127 which becomes a floating lever. The second cylinder' is connected directly to the venturi by an open pipe and the first in a delayed fashion through a throttled pipe. The second cylinder operates upon sudden charges of suction and the first acts as a follow-up device. The lever 127, Fig. 11 (Cancelled), may be controlled by a cylinder in which the pressures on opposite sides of the piston are determined by a valve actuated by a bellows in communication with a second venturi. The valve may be operated by a pair of bellows acting on a floating lever and subjected to direct and delayed suction from the venturi. This subject-matter does not appear in the Specification as accepted.