GB127917A - Improvements in and relating to Indicating Devices for Aeroplanes and other Aerial Machines. - Google Patents

Abstract

127,917. Danielson, O. A. Aug. 27, 1917. Anemometers and air-current indicators ; wind vanes.-In devices for use on aircraft for indicating side-slip, speed, and the angle of incidence, a pressure plate 14, Fig. 7, is carried by an arm 13 pivoted in a casing 10, and a vane 53 is carried by an arm 52 attached to a casing 51 pivotally mounted at the lower end of a tube 39, the upper end of which is rotatably mounted in the casing 10. Movement of the plate 14 operates a speed indicator, while movements due to vertical and horizontal surfaces of the vane 53 operate sideslip and angle-of-incidence indicators respectively. The vane 53 may be replaced by two separate vanes. The movement of the arm 13 is opposed by a series of springe so arranged that their resistance varies with the square of the distance through which the plate 14 moves. The indicator may consist of a single dial in which lamps a, Fig. 13, form a speed scale, lamps c a sideslip scale, and lamps b an angle-of-incidence scale, the circuits being controlled by contact springs 21, 59, 47 working over segments 22, 60. 48. The battery circuit is open until the aeroplane has reached a, predetermined speed, when the arm 13 allows the engagement of spring members 37, 38. Auxiliary audible and visual signals C, B may be operated by means of a relay A to give warning when dangerous speeds &c. are reached. In a modification, mechanical connexions are employed, preferably with a single indicator dial having pointers 66, 67, 68, Fig. 15. The spindles of the pointers 66, 67 are operated by wires 75, 81, Fig. 14, connected to the arm 13 and rotatable tube 39, while the pointer 68 is carried on an endless band 92 operated by means including a wire 86 connected to the vane 53.