Patent GB-368281-A (GB)
Title: Improvements in stabilizing apparatus for ships and aircraft
IPC: G05D1/08
Filed: 1930-11-27
Abstract: 368,281. Stabilizing apparatus for ships and aircraft. MINORSKY, N., 333, Vassar Avenue, Swarthmore, Pennsylvania, U.S.A. Nov. 27, 1930, No. 35757. Convention date, Dec. 21, 1929. [Classes 4 and 13 (i).] . A stabilizing device for ships and aircraft comprises a device continuously responsive to angular deviation and an independent device responsive to velocity of angular deviation with means for varying by the second device the flux of an electromagnetic induction device adapted to produce an E.M.F. proportional to the rate of change of flux, and apparatus to produce and control a stabilizing moment responsive to the controlling devices. In the control apparatus thermionic valves are utilized. In one form, the angular velocity responsive instrument comprises two gyroscopes spinning in opposite directions and connected differentially so that the reactions on rolling are additive and on pitching or yawing subtractive. The device forming the stabilizing moment may be a displaceable weight or external vanes. A weight 1 is adapted to be moved across the ship on guides 2 by means of ropes 4 passing over a system of pulleys to rams 7 of a hydraulic motor device 5. The device 5 is fed by a continuously running pump 13 whose output is variable by movement of a lever 16. The lever 16 is adapted to be operated by a link 32 of the floating type, its upper end 38 being connected to a nut 34 on a screwed spindle 35 and an intermediate point 31 is coupled through linkage to a lever 17 pivoted at 18 and having a forked end 20 engaging one of the rams 7. The screw spindle 35 is adapted to be operated by a differential gear 36 one element of which is driven by a motor 43 under the control of an instrument 52 and the other element is adapted to be driven by a motor 44 under the control of the second device 51. The instrument 51 is a direction or angle indicating apparatus of the long period pendulum type which may contain a gyroscope for the purpose of increasing its period. The pendulum 56, Fig. 3, is supported on a knife-edge 57 and carries at its lower end a roller adapted to move over a shaped segment 59 having contacts 62, 63 therein, its swing containing an insulating segment 64. When it is desired to stabilize the ship in respect of a non-vertical axis the segment 59 can be adjusted by means of a worm 60. When the ship heels roller contact 67 makes contact with one or other of segments 62, 63 and so completes the circuit controlling the motor 44. The instrument 52, Fig. 5, comprises two oppositely rotating gyroscopes 71, 72 and their casings are pivotally mounted within the frame 73 about parallel athwartship axes AA, BB. Four cylindrical tanks 74 . . 77 are secured to the frame and are made of resilient material to form diaphragms. They contain mercury and at their upper parts have capillary glass tubes 79 .. 82. These are adapted to serve as variable resistors and for this purpose contain mercury. When angular velocity of rolling occurs the gyroscopes react, one pair of tanks is compressed and the other pair extended whereby mercury rises in one set of tanks and falls in the other. Constant potential from a battery 95, Fig. 7, is impressed on the tubes 79, 82 and on rolling occurring the potential at 96 rises and at 97 falls or vice versa. This difference in potential is utilized in the filament circuits of two thermionic valves 100, 101 and the plate circuits are connected in series with differentially wound field windings 104 of the generator 53 whose armature 105 is connected to the armature 106 of the motor 43 and whose excitation is constant. The generator 53 has another differential field winding 107 energized from the resistor 108 through a sliding contact 109 displaceable by the shaft 49 and mechanically connected to the armature shaft by motor 43. In order to obtain a control responsive to angular acceleration or deviation the plate circuits of the valves 100, 101 contain the primaries of two transformers and their secondaries are connected to the filaments of a second set of valves and a differential field 134 is made up similar to the field 104. The result thereof is added to the control already impressed on the motor 43. In operation, on the start of a roll the nut 34 will be given a displacement which causes the lever 32 to move about its pivot 31 and so move the control lever 16 whereupon the pump according to its direction of rotation feeds the ram member 5 and so starts the weight 1 in motion, the lever 17 then operating to produce a follow-up action upon the system. In this lever system the member 19 has two stops 110, 111 whereby an emergency lever 23 helps to bring the weight 1 by its action on the pump to rest at the end of the track. The weight 1 may incorporate as its actuating means an electric motor the leads to which are correspondingly made of flexible conductors.