Gyroscopic instrument

Claim 1

In a gyroscopic instrument, the combination comprising a frame, a gyroscope rotor including a co-axial drum-shaped sleeve of a non-magnetic and electrically conductive material, means for mounting said rotor within said frame for rotation and for universal pivotal movement about axes intersecting the axis of rotation of said rotor, a magnetic device having outer magnetic pole means, inner magnetic pole means surrounded thereby and a gap therebetween, the field lines produced by said pole means extending transversely through said gap, means on said frame and on said magnetic device for so mounting said magnetic device non-rotatably as to locate said sleeve within said air gap with a radial clearance affording said sleeve pivotal movability relative to said magnetic device about said axes, and driving means carried by said frame and connected to said rotor whereby rotation of said gyroscopic rotor causes said magnetic device to induce eddy currents in said sleeve producing electro-motive forces and a resultant tendency of said rotor, in event of a deviation of the rotor axis from the axis of said magnetic device, to perform a precessional motion eliminating said deviation, the gap of said magnetic device being confined by a pair of evenly spaced opposed annular cylindrical faces of said pole means, the width of said faces being smaller than the axial length of said sleeve, both ends of said sleeve projecting out of said gap, said magnetic device being of a type producing in said gap a magnetic field of circumferentially uniform strength between said opposed annular faces, said magnetic field being normally located symmetrically with respect to a median plane extending transversely of said gyroscope rotor, said plane containing the point of intersection of said axes about which said universal pivotal movement takes place.