Patent GB-811061-A (GB)
Title: Aircraft navigation instruments
IPC: B64D45/00
Filed: 1955-06-01
Abstract: 811,061. Navigation instruments for aircraft. SPERRY RAND CORPORATION. June 1, 1955 [June 11, 1954], No. 15766/55. Class 4. An aircraft navigation instrument comprises a hollow truncated spherical member 105, having a horizon-defining line 105<SP>1</SP>, which encloses a vertical gyro comprising a rotor case 106 pivotally supported in a roll gimbal for rotation about an axis 108 parallel with the pitching axis of the aircraft, the gimbal being in turn mounted for rotation about an axis 109 parallel with the roll axis of the aircraft. As the aircraft rolls or pitches the vertical gyro will restrain the member 105 in space whereby inclination of line 105<SP>1</SP> or vertical movement of the line with respect to a fixed reference index 127, Fig. 6, will indicate the actual attitude of the aircraft. Movement of the member 105 is effected through a gear train 111, 112. Cross pointer indicators 121, 122 which indicate desired attitude in azimuth and elevation are mounted in front of member 105 for movement by meter movements 124 and 125 which are respectively actuated in accordance with the outputs of summing amplifiers and limiters 61 and 65. The inputs to azimuth summing amplifier 61 are derived from a radio receiver 15 and a gyro compass 16 and course selector 60 the outputs therefrom being supplied through selectable switches 62 to the amplifier 61. A further signal proportional to the bank attitude of the aircraft is derived from a roll synchro 134 and fed to amplifier 61. Similarly the inputs to elevation amplifier 65 are derived from a radio receiver 18 responsive to the output of a glide slope system and an altimeter 19 which supplies a signal proportional to deviations in the altitude of the aircraft from a predetermined altitude, the outputs of receiver 18 and altimeter 19 being supplied through selectable switches 66 to the amplifier 65. A further signal proportional to the pitch attitude of the aircraft is derived from a pitch synchro 135 and fed to amplifier 65. The intrument is housed in a casing 123 having a viewing opening 126 with index 127 inscribed on the glass cover thereof. The course selector 60 is adjusted by a knob 130 until the bearing of the selected course appears on the drum-type indicator 131 and a further counter 132, controlled by the compass 16, indicates the magnetic heading of the craft. A deviation indicator 133 may be provided for indicating the magnitude of the displacement of the craft from a selected course such as defined by a directional radio beam. By this apparatus the pilot is provided, by pointers 121 and index 127, with an indication of the difference between demanded bank angle and actual bank angle and by pointer 122 and index 105<SP>1</SP> with an indication of actual bank angle. A further embodiment is described wherein the line 105<SP>1</SP> or its equivalent is marked on a flexible tape mounted on rollers for vertical movement with respect to the viewing window, the rollers being supported in a frame capable of " rolling " movement about an axis normal to the surface of the window. Specifications 690,985, 733,024 and 811,063 are referred to.