Patent GB-341592-A (GB)
Title: Improvements in gyroscopic apparatus
IPC: G01C19/00
Filed: 1929-11-04
Abstract: 341,592. Gyroscopic apparatus. GRAY, J. G., La Mancha, Victoria Circus, Dowanhill, Glasgow. Nov. 4, 1929, No. 33466. [Class 97 (iii).] Stabilizing or steering apparatus for use on moving vehicles comprises a gyroscope having a horizontal axis of rotation and attached by vertical pivots to a frame which is attached by horizontal pivots, at right-angles to the axis of spin of the gyroscope, to a fork &c. The centre of gravity of the gyroscope and its casing lies to one side of the line of the vertical pivots and means are provided for training or turning the frame so that the axis of spin is maintained perpendicular to the frame. In the simple form shown in Fig. 1, the gyroscope 1 is attached by pivots 2 to a frame 3 which is attached by pivots 4 to uprights 5 carried by a base 6. The gyro-casing is loaded by a mass 7 to bring its centre of gravity to one side of the pivot axis 2-2. To use this device for steering, the pivot axis 4-4 is arranged athwart the vehicle and the vehicle is steered so that the axis of spin of the gyroscope is maintained perpendicular to the frame 3. To indicate this position of the axis one of the pivots 2 may carry an arm 10 having a roller 11 co-operating with contacts 12, 13, separated by insulation, the contacts being arranged in the circuits of signal lamps. If the frame 3 tilts about the axis 4-4 the mass 7 applies a restoring couple to the gyroscope so that a sighting-device carried by the frame is stabilized about the said axis. The frame carries a reversible motor 8 which operates vanes 9 applying a torque about the pivots 4 and causing the gyroscope to precess about the pivots 2. If the vehicle is steered to keep the gyro-axis perpendicular to the frame it will be turned in the direction, and at the speed, of the precession. Instead of being fixed on the gyro-casing the mass 7 may be arranged to be displaceable along a screw to enable the gyroscope to be brought into a state of neutral equilibrium. Fig. 5 shows an arrangement in which the couple causing the gyroscope to turn about the pivots 2 is applied by an auxiliary gyroscope 1<1> which is rigidly attached to the frame 3 with its axis at right-angles to the plane of the frame. The angular momentum of the gyroscope 1<1> is equal and opposite to that of the gyroscope 1. With this arrangement, when the whole apparatus is turned in azimuth, the gyroscope 1<1> applies to the gyroscope 1 a couple of the correct magnitude to cause it to precess about the pivots 2 with an angular velocity equal to that of the azimuth movement of the apparatus. The single reversible motor of Fig. 1 is replaced by two motors 8 arranged to run in opposite directions and controlled by the contactmaking device 10 .. 13 in such manner that the axis of the gyroscope 1 is maintained perpendicular to the plane of the frame 3. The frame is stabilized into the vertical plane provided the pivots 4-4 lie athwart the vehicle. If the pivots 4-4 lie fore- and-aft and the vehicle turns the frame 3 will seek the apparent vertical. An arrangement which obviates this defect is shown in Figs. 6 and 7. The gyroscope 1 is neutral with respect to the pivots 2 and is centralized by springs 27 as described in Specification 274,268, [Class 97 (iii), Thermometers &c.]. The frame 3 is pendulous with respect to the pivots 4. The gyroscope 1<1> is attached to the frame by two vertical spindles and worm gear 28, 29 is provided by which the axis of this gyroscope can be set at any desired angle to the frame. When the frame departs from the vertical plane the apparatus executes pendular oscillations and the gyroscope 1 precesses about the pivots 2. When the roller 11 makes contact with one of the plates 12, 13 one of the motors 8 is started and a torque is exerted which causes the frame to settle in the vertical plane. If the gyroscopes 1, 1<1> are similar and rotate at the same speed in opposite directions the axis of the gyroscope 1<1> is set at such an angle that its component of spin lying across the frame is Cn-MVh where Cn is the angular momentum of either gyroscope, M the mass of the system carried by the frame 3, V the speed of the vehicle, and h the distance of the centre of gravity of the system below the pivots 4. In these circumstances if the vehicle turns with a given angular velocity the gyroscope 1 will precess at the same angular velocity and the resting position of the device on the turning vehicle is that in which the frame 3 is in the true vertical and the roller 11 rests on the insulating strip 14. The value of h can be adjusted by means of a displaceable mass 31. A development of this form is described in which there is pivotally mounted on the frame 3 a second frame having its plane vertical and at right-angles to that of the first frame. The second frame carries two gyroscopes as above described. A mirror &c. carried by the second frame is stabilized by this arrangement against oscillations of the vehicle in any plane. Fig. 10 shows an arrangement in which the frame 3 sets itself into the true vertical and is mounted on a platform which is turned in azimuth with respect to the vehicle. The pendulous frame 3 carries two similar gyroscopes 1, 1<1>, the gyroscope 1 being capable of precessing about the pivots 2 and the gyroscope 1<1> being rigidly attached to the frame, so that when the base turns in azimuth the gyroscope 1<1> gives rise to a couple causing the gyroscope 1 to turn with the base. A small gyroscope 39 is carried by a frame 48 mounted on a vertical axle 40 which can be rotated through worm gear 41, 42 by a reversible motor 43. The angular momentum of the gyroscope 39 is adjusted to be equal to MVh, defined above. When the base of the instrument is turned relatively to the ship the frame 48 is arranged to be turned by the motor 43 so that the axis of the gyroscope 39 is always perpendicular to a fore-and-aft line. The motor is controlled by a brush 46 attached to the frame 48 and moving over a rheostat 47 carried by the frame 3, and by a second brush, not shown, attached to the base of the instrument and moving over a rheostat carried by the ship.