GB331627A - Improvements relating to gyroscopic turn indicators - Google Patents

Abstract

331,627. Brown, S. G. May 3, 1929. Gyroscopic apparatus.-A turn indicator for aircraft, &c. comprises a gyrowheel having its axis normally horizontal and suspended with three degrees of freedom, in combination with resilient mea.ns for restraining tilting of the gyro-wheel axis in either direction about a horizontal axis and yielding means opposing movement of the gyro-wheel axis about a vertical axis. In one form, Fig. 2, the gyrowheel 10 is carried in a frame 12 supported in neutral equilibrium on horizontal pivots 14 within a frame 16 which is mounted on vertical pivots 18 in a fixed frame 26. Tilting of the frame 12 about the pivots 14 is restrained by a spring 20 having one end attached to the frame 12 and the other end connected by a cord 29 to a winch 32 which can be turned by a finger-piece 34 to vary the tension of the spring 20. Movement of the frame 16 about the axis 18 is restrained by the friction between a pad 22 carried bv the frame 16 and the surface 24 of the frame 16. The surface 24 is preferably part of a cylinder having a radius greater than the distance 18-24, so that the frictional resistance increases with increasing amplitude of movement. The pad 22 is urged against the surface 24 by an adjustable spring 46. An index plate 50 carried by one of the pivots 14 co-operates with a dial 52 fixed to the frame 16. In another form, Figs. 6 and 7, the pivot axis 18 is at one end of the frame 16 and springs 66 are provided to centralize this frame, the friction between the members 22, 24 being in this case the same in all positions of the frame. The dial 52 is mounted on the fixed frame 26 and the index plate 50 is fixed to a spindle 70 journaled in the fixed frame. This spindle carries a gear wheel 72 gearing with a wheel 74 on the pivot 14, and the axis 18 passes through the point at which these wheels mesh.