GB768456A - Improvements in or relating to navigational instruments - Google Patents

Abstract

768,456. Aircraft indicators. SMITH & SONS, (ENGLAND), Ltd., S. July 14, 1955 [July 16, 1954], No. 20852/54. Class 4. An aircraft instrument comprises a first index 13, 14, rotatable in a plane about an axis 5 in accordance with the angle of roll, a second index 23, 24, the two indices being shaped and disposed so that their relative angular disposition indicates the aircraft bank relative to the horizontal, a first pointer 16 linked to the first index so as to be displaceable from a datum in accordance with bank and a second pointer 19 displacable from the datum in accordance with a required angle of bank, so that when the two pointers coincide, the aircraft is in the required bank altitude. The second index is displaceable in accordance with the aircraft pitch. In Fig. 1, the index 13, 14 and the pointer 16 are controlled by a milliammeter 6, the axis of which coincides with axis 5. The pointer 19 is rotatable about the same axis by a milliammeter 17. The second index 23, 24, comprises also a circular portion 25, and is controlled vertically by a milliammeter 20. The portion 25 co-operates with a pitch scale 28 secured by arm 30 to the casing of a milliammeter 21, the movement of which controls a pointer 27 moveable over the pitch scale. A knob 35 can adjust the pitch scale 28 and pointer 27 vertically, without effecting their relative position, by rotating meter 21 bodily about the axis of its movement. The meter 6 is connected to a pick-off 36 on a gyro vertical 37, Fig. 5, so that the index 13, 14 and pointer 16 indicate the bank angle. The meter 20 is connected to a second pick-off 45, so that the index 23, 24, 25 is adjusted in accordance with pitch. The meter 17, controlling pointer 19, is connected to a summing device 38, connectable through switch 39 to a gyro-compass 41, so that the pointer 19 is displaced from its datum in accordance with deviation from a required heading. By closing switch 43, the meter 17 is connected to an output from a radio beacon receiver 44, so that displacement from the beacon track displaces pointer 19. Switch 39 can add a rate of approach signal derived from a rate amplifier 42. Meter 21 can be connected by switch 46 to a second output from the beacon receiver 44, so that deviation in pitch from the required glide path moves pointer 27. In this case, knob 35 is used to adjust scale 28 in accordance with the known angle of glide required. Meter 21 may also be connected to a height responsive device 48, an airspeed responsive device 50, or each, so that pointer 27 can be observed when flying at constant height, constant speed, or in steady level flight. Specification 586,506 [Group XXXVIII] is referred to.