Patent GB-361836-A (GB)
Title: Improvements relating to navigational instruments for aircraft
IPC: G01C19/44
Filed: 1930-05-22
Abstract: 361,836. Gyroscopic apparatus. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A. -(Assignees of Bassett, P. R. ; 104, Broadway, Rockville Center, and Sperry, E. A. ; 115, Ocean Avenue, Brooklyn, both in New York, U.S.A.) May 22, 1930, No. 15740. Convention date, May 23, 1929. [Classes 97 (ii) and 97 (iii).] A single indicating member is operatively connected by means such as gearing or linkage to a universally mounted gyroscope and indicates the attitude of an aircraft about both transverse and longitudinal axes by its position relative to a member fixed to the aircraft. In one form, the face of the instrument represents the forward outlook from the aircraft, a part 2 representing a fixed part of the aircraft and a bar 3 the horizon. The bar 3 is caused by an electrically driven gyroscope 15 to move up and down or tilt to represent the movements of the horizon due to movements of the aircraft. The gyroscope is mounted by trunnions 13, 14 in the ring 7 which is supported by trunnions 10, 11 in the casing 6. The bar 3 is bent to pass through a slot 4 in the backing plate 5 and is clamped at 8 to a rod 9 pivotally mounted in the gimbal ring 7 to which the plate 5 is also fixed. The rod 9 is connected by links 17, 18 to the gyro casing so that it rotates in the reverse direction to the rotation of the gyro casing about the pivots 13, 14. To provide for the variable attitudes in which a craft flies when loaded differently the member 2, Fig. 2, is adjustable by the thumb-piece 26. The indicator is provided with markings 21 for estimating the extent of pitch or roll and with a banking indicator consisting of a curved glass tube 24<1> containing liquid 25<1> and a ball or roller 261. Figs. 9 and 10 show a further form of banking indicator in which a hollow metal roller 27 containing a smaller roller 29 and partially filled with liquid 28 is guided in a curved track 30 provided with a pointer 341. In a further form the hollow roller 27 contains a heavy liquid such as mercury and a lighter viscous liquid such as oil or a mixture of glycerin and alcohol. In a still further modification two rollers, one a solid steel roller and the other a hollow roller are caused to roll together, the one acting as a drag on the other. In a second form similar to that shown in Figs. 1 and 2, the artificial horizon, a gyroscopic turn-indicator and a magnetic compass are embodied in a single casing. The gyroscope is air driven and of the type described in Specification 220,726, [Class 97 (iii),- Thermometers &c.]. The bar 3 is pivoted to a gimbal ring with which it is made to tilt and is caused to rise and fall as the aircraft pitches by the engagement of a pin on the gyro casing with a slot in the extension of the bar 3. In a modification of the invention shown in Fig. 7 the horizon is represented by members 41 fixed to the aircraft whilst a bar 39 mounted on a stub shaft 36 carried by a gimbal ring represents the aircraft. The bar 39 is caused to tilt by the engagement of a pinion 37 on the stub shaft 36 with a pinion 38 on the longitudinal axis of the gyro casing and rises and falls with the gimbal ring to represent the attitude of the craft by reference to the horizon representation 41. Adjustment for different loading of the aircraft is effected by altering the tilt at which the device is attached to the instrument board.