Improvements in and relating to gyroscopic compasses

摘要

544,094. Gyroscopic compasses ; bearings. SPERRY GYROSCOPE CO., Inc. June 1, 1940, No. 9604. Convention date, June 21, 1939. [Class 97 (iii)] [Also in Group XXXIV] A gyroscope compass comprises two rotors spinning about spaced parallel axes in a common rotor bearing frame which is tiltable about an horizontal axis in a support mounted for rotation about a vertical axis. The two rotors 29, 291, Fig. 1, spin within casings 34 mounted for oscillation about an east-west axis in spherical air bearings 341 carried by a vertical stem 25. The stem is rotatable about its vertical axis, in air cups 65 forming part of a spider 16 resiliently connected by rubber discs 60, 61 to an inner gimbal ring 13 pivoted within an outer gimbal ring 12. The outer gimbal ring is carried by a bracket 10 supported by a rotatable hollow stem 6. Air for driving the rotors and supplying the air bearings passes up the hollow stem 6, through pipes 21, hollow pivots of the gimbal rings, chambers 67, 671 and nozzles 30, 301 finally escaping downwardly in a neutral direction through baffle plates 92, 93. The rotor shafts are supported in anti-friction bearings and one bearing of each rotor is axially loaded by springs 33, Fig. 6, the two loadings acting in opposite directions to cancel out changes of balance due to expansion and contraction. Compass cards 3, 5 are viewed through an annular window 2 and glass dome 4. The outer frame 10 is caused to follow the compass by gearing 621, 83 driven by an azimuth motor 84 controlled by a pick-up device, for example a three-legged transformer 70 on the spider 16 and a core 71 beneath the compass card 5. Liquid gravity control.-For imparting meridian seeking properties to the compass a pair of mercury containers 36, 36', Fig. 4, connected at the bottom by a tube 38 as usual, is secured to the rotor casings so as to tilt with the gyroscopes, and a smaller tube 39 with an expansible chamber 40 is connected to the top of the containers, the tube 39, chamber 40 and space above the mercury being filled with alcohol to retard the flow of the mercury. Damping oscillation.-For damping the compass air is byepassed through a tube 90 and through a hollow arm 50, Fig. 5, pivoted on air bearings on the rotor casings, the hollow arm being located in a north-south direction. A pendulum 41 dipping into an oil bath 45 is rigid with the hollow arm. If relative tilt occurs between the pendulum and the gyroscope, air issuing from the end of the hollow arm is directed partially through one or other of two oppositelydirected nozzles 57, 58 to exert a torque and thereby reduce the tilt and produce damping. In the mid-position, the air passes entirely through a tube 59 without applying torque.