GB686862A - Improvements in or relating to gyro-verticals - Google Patents

Abstract

686,862. Gyroscopic apparatus. SPERRY CORPORATION. Sept. 22, 1950 [Sept. 24, 1949], No. 23250/50. Class 97 (iii). [Also in Group XXXVIII] A gyrovertical such as for aircraft comprising a rotor case 1, Fig. 1, pivoted about fore-andaft major trunnions 2 and minor athwartship trunnions 3 within a gimbal ring 4 has a pendulum mounted thereon about axis 11<SP>1</SP>, 121, parallel to the fore-and-aft and athwartship axes respectively, the pendulum housing a rotor 6, Fig. 3, for spinning in bearings 7 and 8 about the axis 12<SP>1</SP>. In the initial adjustments mass 23 is so positioned on the threaded shaft 231 depending from the casing 9 that the auxiliary gyroscope is neutrally balanced about axis 11<SP>1</SP>, 121. The mass 50 on the base of the main gyroscope balances the mass of the auxiliary gyroscope excluding mass 23 and so a small mass 51 is adjusted on its threaded stem, depending from case 1, until the whole assembly is balanced about axes 2 and 3. The mass 23 is finally moved down so that the pendulosity of the entire assembly is equal to that of the auxiliary gyroscope and is such that during a turn at a prescribed speed the pendulum remains vertical. Pick-offs determine the relative tilt between the pendulum and case 1 and supply signals to torque motors 21, 22, to erect the case. The pick-offs may comprise four tension wires 15, 151, 16, 16<SP>1</SP>, Fig. 1, whose impedances vary with strain and which are anchored at their outer ends to the top of case 1 and at their inner ends to stem 23<SP>1</SP>, each pair of strain gauges being connected in the form of a Wheatstone bridge circuit for providing an output signal applied through an amplifier to the corresponding torque motor. Alternatively, the lower end of stem 231 may support a dish-shaped disc 28, Fig. 3, which is normally symmetrical with respect to cruciformly positioned polepieces such as 30, 30<SP>1</SP>, 31 attached to the case 1 and each provided with a winding. The winding on the central polepiece is excited from a single phase supply and the winding on opposite poles are connected in opposition through an amplifier to the respective torque motor for erecting case 1. To maintain the pendulum vertical during turns at any speed and during changes of speed, the rotor speed of the auxiliary gyroscope is controlled in accordance with the speed of the craft, by supplying the spinning motor field 51 with the amplified output of a polyphase generator driven from a fan in the slip stream. The auxiliary gyroscope is mounted by means of leaf springs 14, 14<SP>1</SP> and 13, 131 in its gimbal ring 10 and brackets 11, 12, or in a modification normal bearings are used. Transmitters 53, 54 transmit the indication of the entire assembly. Specification 641,360 is referred to.