GB471537A - Improvements in or relating to aerial flight instruments - Google Patents

Abstract

471,537. Gyroscopic apparatus. CRANE, C. J. March 5, 1936, No. 6671. Convention date, March 6, 1935. [Class 97 (iii)] [Also in Groups XIX and XXIX] In an aircraft instrument a member indicating the amount of turn of the aircraft is actuated by fluid flow means regulated by means responsive to the rate of turn. In the form shown the spindle 4 of the turn indicating disc 1 is geared to a spindle 9 carrying a magnetic drag type of damper 15 and an impeller 17. A constant, air jet 26 is directed on to the impeller 17 by a vane 23 fixed on the gimbal axle 24 of a gyroscopic rate of turn indicator 25 so that the movement of the impeller 17 is proportional to the integral with respect to time of the movement of the axle 24, i.e. is proportional to the amount of turn. In front of the turn indicating disc 1 is arranged a bank indicator comprising a member 2 simulating an aircraft and rotated on its pivot 58 by an endless chain 64, gearing 69, 70, and pendulous gyroscope 46. Arranged between the turn indicator 1 and bank indicator 2 is a bar 3 which is raised or lowered according as the aircraft dives or climbs by a lever 73 pivoted at 83 and rocked by an eccentric cam 93. The latter is operated through gear sectors 100, 102 by a tappet 106 on one wall of a sealed deformable capsule 105 which is connected at 109 to a large sealed air reservoir (not shown) and communicates with the atmosphere through a capillary leak tube 110. The post 84 supporting the pivot 83 rests by means of knife edges 85, 86 on a bimetallic strip 87 which effects temperature compensation. The position of the pivot 83 may also be adjusted by hand from the knob 91. The gyroscopes 25, 46, and impeller 17 are housed in an air tight casing C from which air is withdrawn continuously at 28. Air enters through pipe 31 to supply the driving jet 32 for the gyro 25 and the jet 26 for the impeller 17 and also at 52 to drive the gyro 46. The air pressure inside the casing C is maintained constant by an adjustable spring controlled pressure relief valve 33. The casing C is inserted within the casing B formed at the top and one side with a chamber D for housing the capsule 105 and its associated mechanism and the indicating members. The lower part of the turn indicating disc 1 is masked by a part 56 of the casing B which is provided with a fixed pointer 55 co-operating with graduations on the disc 1.