GB712993A - Devices responsive to changes in speed and direction for producing signals for controlling dirigible platforms - Google Patents

Abstract

712,993. Gyroscopic apparatus. 1VENSKA AEROPLAN AKTIEBOLAGET. May 15, 1951, No. 11366/51. Class 97(3) [Also in Groups XIX, XXIX and XXXVIII] Apparatus responsive to changes in speed and direction for producing signals, e.g. for indication or for stabilizing and steering dirigible platforms comprises a frame, a gyroscopic casing 7, Fig. 1, rotatably mounted in the frame on a spindle 8 and carrying a rotor 9 mounted to spin about an axis perpendicularly to the spindle 8, damping means 1 including a displaceable member within a casing 1 and adapted to resist any movement forced thereupon by a resistance proportional to the speed of said member, an elastic spring member 5 connecting the gyroscope casing 7 to the displaceable member of the damping device, and a signal generating device 10, 11 for providing signals indicative of the position of the rotor housing 7 relative to the frame. The gyrocasing 7 is deflected about its axis 8 in accordance with the rate of turn of the frame about a reference axis perpendicular to the spin axis of the rotor 9 and to the axis 8 of the casing 7 and due to the force exerted by the casing'7 on the movable member of the damping device the displacement of this member and hence of arm 2 to which said member is connected integrates the rate of turn to provide a measurement of the angle turned .through by the frame and the momentary position of the gyro casing 7 relative to the frame compounds the deflection of the rotor casing due to the angular position of the frame and the rate of angular change of the frame about the reference axis and the composite measure is represented by the output signal from the device 10, 11. Such a damping device may comprise a plunger movable in a cylinder filled with liquid and designed with a narrow passage for the flow of the liquid between the plunger and cylinder, or an eddy current-brake device. In order to render the displaceable member of the damping device sensitive to linear acceleration, the arm 2 carries a weight 4. The movement of the arm in time integrates the acceleration and gives an indication of the linear velocity. To obtain a measure of linear acceleration a weight 6 is carried on the gyrocasing 7, the spring 5 being connected between the weights 4 and 6. The momentary position of the gyrocasing relative to the frame then compounds the deflections of the casing due to the linear acceleration and velocity of the vehicle in addition to the angle and rate of turn. A signal indication of the composite measure is obtained from the signal generating device 10, 11, and applied to an indicator or control device 12, e.g. for stabilizing an aeroplane or platform. By changing the constant of the spring 5 and adjusting the relationship between the weights 4 and 6 or the damping constants of the damping device, the magnitudes of the different components can be varied. One form of signal generating device comprises an iron plate 60, Fig. 6, secured to the gyrocasing 7 so as to move in the magnetic field surrounding an E-core 61 excited by a coil 62 on the centre limb, a differential output signal from coils 63, 64 on the other limbs is obtained across terminals 121, 122, the polarity and amplitude of which signal depends upon the position of the plate 60 relative to the cone. In a pneumatic form of position-indicator, air or gas is blown from a nozzle 71, Fig. 7, in the rotor casing 7 against two receiving nozzles 72, 73, a pressure difference being created in these nozzles depending upon the position of the nozzle 71 in relation thereto and is used as a composite signal output. A shield 74 may be arranged in front of the nozzles 72 and 73 and such shield is fixed to the coil of a measuring instrument, e.g., an altimeter or target finding means so that the position of the shield is determined by a signal fed to the instrument, the shield superimposing such signal on the pressure difference signal from the nozzles 12. Means, such as a pair of oppositely disposed solenoids arranged to act on an iron cone attached to the arm 2 may be provided to counterbalance a part of the forces emanating from the gyro 9 or from the weights 4 and 6 when the measuring device is moving. The arm 2 of the damping device may be caged or brought to a zero position by a leaf spring device electromagnetically operated.