Abstract: A vibratory angular rate sensor of the kind comprising a hollow cylinder (3) secured at one end to a base (5) and free at the other end and transducers (9) on the cylinder (3) for exciting and detecting radial vibrations in the cylinder wall. The transducers (9) are positioned near the end of the cylinder (3) secured to the base (5), and the base (5) rigidly fixes the adjacent end of the cylinder (3) thereby to maximise coupling of the transducers (9) to vibrations produced in the cylinder (3) in operation of the sensor.

Abstract: A gyroscopic device comprising a beam, column or other continuous unitary structure of consistent vibratory characteristics along its full length and including piezoelectric material. The piezoelectric effect is used both excite the structure into resonant vibrations along a first axis and then, when a rate of turn is applied along a second axis at right angles to the first, to detect that rate of turn by sensing vibrations set up in the beam in a direction parallel to a third, orthogonal axis due to Coriolis forces resulting from the applied rate of turn. The beam may be held at both ends, or may be supported at one end only with the other end free. The vibrations applied to and sensed within the beam by means of the piezoelectric effect may be parallel, transverse and radial relative to the beam axis, or may be in a rotary sense around that axis. A mode of vibration in which opposite faces of the beam oscillate in parallel directions but out-of-phase is also disclosed.

Abstract: Gyroscopic apparatus in which the rotor is elastically-connected to its drive, whereby deflection of the rotor bends the connection and thus sets up a deflection torque which acts upon the rotor. The connection of the rotor to the drive also includes masses carried by springs. When the rotor deflects, these masses oscillate in directions parallel to the driving axis, and when the rotor is spinning at a certain (tuning) speed the sum of the oscillating forces exerted upon the rotor by the individual moving masses will be a steady quantity which may be made equal and opposite to the deflection torque. The apparatus may thus behave like a "free rotor" gyroscope.