Patent GB-950416-A (GB)
Title: Steering and horizon indicating instrument for aircraft
IPC: B64D45/00
Filed: 1962-02-08
Abstract: 950,416. Aircraft instruments. COLLINS RADIO CO. Feb. 8, 1962 [May 3, 1961], No. 4874/62. Heading B7W. An aircraft attitude and command indicator instrument comprises an horizon simulating indicator, an aircraft simulating reference rigidly affixed to and symmetrically disposed with respect to the longitudinal and transverse axes of said instrument, means for stabilizing said horizon simulating indicator in pitch and bank attitudes with respect to an aircraft within which said instrument is mounted, a second indicator, said second indicator being juxtapositionable adjacent the edges of said aircraft simulating reference, means for rotating said second indicator about the longitudinal axis of said instrument in accordance with the signal commanding a change in instantaneous aircraft bank attitude, and means for displacing said second indicator radially from said instrument longitudinal axis in accordance with a signal commanding a change in instantaneous aircraft pitch attitude. Disploy (Fig. 2).-A front face-member 10 is formed with a transparent circular face 14 to the rear surface of which is fixed a simulated aircraft index 13 which extends both transversely as shown and also inwardly along the axis of the instrument. A horizon line 19 is marked on a tape which carries also markings 25, 26, the markings being movable vertically with respect to index 13 to indicate degree of pitch and rotatably about the axis of the instrument so that a mark 22 (to be described) is read against a fixed scale 21 to indicate degree of bank. Masking members 11, 11a carry index marks 19a and 19b which provide a zero reference for a further indicator comprising indices 65, 66 which extend transversely and inwardly of the instrument and in the undeflected position shown in the Figure conform to the upper profile of index 13, and when deflected provide an indication of demanded pitch and bank. A still further index 90 shaped to represent the approach view of a runway is associated with index 19 when banked and is separately movable upwardly towards the axis of the instrument to provide an indication of altitude and also laterally to indicate deviation from a selected course. Operation (Fig. 1): Horizon indicating assembly.-Line 19 is marked on a tape 34 supported in a frame 33 by idler rollers 37, 38 and spools 43, 44, spool 44 being spring-loaded and spool 43 being driven through gearing 46-48 from a pitch attitude servomotor 41. Frame 33 is mounted on a shaft 39 rotatably mounted in a rear casing member 100 and is driven through gearing 105, 106 from a bank attitude servomotor 108. Demanded attitude assembly.-Indices 65, 66 are attached to links 53, 54 connected to the extremities of U-shaped arms 51, 52, each pivoted to a plate 60 attached to a shaft 101 rotatably mounted on rear member 100, and driven through gearing 104, 112 from a roll demand servomotor 110. Demanded pitch movements are transmitted through arm 51 from a pitch demand servomotor 61. Course deviation and altitude assembly.- Index 90 is attached to one end of a flexible steel tape 87 which is wound on a spool 81 driven through gearing 82, 83 from an altitude servomotor 85, the whole assembly being mounted on an arm 78 which carries a rightangle guide member 88 for the tape whereby unwinding of the tape from the spool causes index 90 to be moved upwardly. The arm 78 is carried by a shaft 77 rotated by a course deviation servomotor 74 carried by a bracket 70 fast with shaft 39 whereby index 90 may be rolled in unison with horizon line 19. Specification 819,456 is referred to.