Patent GB-971984-A (GB)
Title: Improvements in or relating to gyroscopes
Inventor: SCOTTO DOMINICK PETER
IPC: G01C19/42
Filed: 1963-04-17
Abstract: 971,984. Rate gyroscopes. AMERICAN BOSCH ARMA CORPORATION. April 17, 1963, No. 15149/63. Headings G1C and G1N. A rate gyroscope comprises a spherical inertial mass resiliently constrained to a framework rotated about an X axis by a motor, wherein the resilient members measure the torque produced along perpendicular Y, Z axes when the gyro stator has an angular velocity about an axis in a plane through the X axis, the individual torque being proportional to the angular velocity components in the XY and XZ planes, and may thus be combined to give the magnitude and angular direction of the axis of the angular velocity of the stator in the YZ plane. The rotating member also carries a linear accelerometer. As shown (Figs. 1, 2) the rotor comprises a spherical inertial mass 17 suspended in fluid 18 in a cylindrical framework 15, mounted for rotation about an X axis by bearings 11 in a stator 12. The body 17 is attached to the framework by a first pair of rigid rods 19, 20 (Fig. 1) in the XY plane, and a second pair of rigid rods 25, 26 (Fig. 2) in the XZ plane, the rods being secured to anchor blocks 21, 22, 27, 28 on the body 17, and piezoelectric transducers 23, 24, 29, 30 on the framework 15. The rotor assembly is driven about the X axis by an A.C. -energized coil 37 on the stator 12 coupling with a magnetic ring 38 on the rotor. If the stator has a component of angular velocity about its own Z axis, this produces a proportional torque on the rotor about its Y axis which makes the rotor follow the stator. This torque is produced in rods 25, 26 and measured by transducers 29, 30. Similarly, a component of angular velocity of the stator about its Z axis produces proportional torque on the rotor about the Y axis, which is measured by transducers 23, 24. The differences between the signals in the individual transducers of each pair, which are proportional to the torsional forces and hence the angular velocity components, are combined electrically (Fig. 6, not shown) to determine the magnitude of the resultant angular velocity and the direction of its axis in the YZ plane relative to a reference direction determined by the signal developed in a coil 40 as the stator IZ by a magnet 41 carried by the rotor framework 15 in a position defining angular velocity of the stator about its Z axis. The transducers 23, 24, 29, 30 may be strain gauges or magnetostrictive devices, and the rods 19, 20, 25, 26 may be radial with respect to the splerical mass 17. A linear accelerometer is located in the middle of the inertial mass 17 and comprises a thin piezoelectric strip 49 coaxial with the rotational axis X of the rotor, and carrying a weight 53 at its centre which produces an A.C. signal whose amplitude is proportional to the magnitude of the linear acceleration and whose phase relative to the reference signal in coil 40 is indicative of the direction of the linear acceleration in a plane containing the X axis. The plug and socket connections 56, 57, 58 to the bar 49 may be made sufficiently stiff and self-lubricating to obviate the need for bearings 11.