GB562886A - Improvements in or relating to rate of turn meters and bank indicators - Google Patents

Abstract

562,886. Gyroscopic apparatus. BENDIX AVIATION CORPORATION. Dec. 9, 1942, No. 17548. Convention date, April 17, 1942. [Class 97 (iii)] In a rate-of-turn gyroscope 'and attitude indicator for aircraft, precession is opposed by a force which is a function of the tangent of the angle through which the gyroscope precesses. The angle of deflection of the gyroscope during turning at a predetermined air speed (for which the instrument is calibrated) is arranged to be substantially equal to the angle of bank so as to give a true measure of the rate of turn at that bank. As shown in Fig. 3, the precessional movement of the gimbal 11 supporting the airdriven rotor 9 with two degrees of freedom is resisted by a pair of oppositely-wound springs 35, 36; the outer coils of which make contact successively with (or move away from) rings of inwardly-directed stops 38, 39 as the springs unwind or wind up. By adjusting the stops, the resistance of the springs may be made to conform to a tangent law. The shaft 14 of the gimbal carries a fork 19 which operates a rod 20, lever 21, hollow shaft 22 and a rotatable dial 23 calibrated to indicate rate of turn in degrees per minute. The scale is read against a fixed pointer 25 attached to a ring 26 on the instrument case. Horizontal lines 28 are marked on the dial to serve as an horizon reference. During a properly banked turn when flying at calibration speed, the horizon lines 28 remain horizontal with respect to the ground. Bank of the aircraft is indicated by a miniature airplane 40 attached to a shaft 41 connected by a fork 43 to a pendulum 46. The miniature aircraft is read with reference to pointers 48 on the casing and with reference to the horizon lines 28. U.S.A. Specifications 1,407,491, 1,894,038 and 2,249,914 are referred to.