Patent GB-366058-A (GB)
Title: Improvements in or relating to direction maintaining means for dirigible craft
IPC: G01C19/00
Filed: 1930-08-20
Abstract: 366,058. Magnetic compasses ; gyroscopic apparatus. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A.-(Assignees of Sperry, E. A. ; 682, Ocean Avenue, Brooklyn, New York, U.S.A.) Aug. 20, 1930, No. 24923. Convention date, Nov. 29, 1929. [Classes 97 (ii) and 97 (iii).] Automatic steering gears for water and air craft include a free non-pendulous gyroscope adapted to control the steering gear and having means for impressing a torque about the horizontal axis of the gyroscope. The torque may be applied from a magnetic compass which is utilized to correct gyroscope wander. The course may be reset by the application of the torque. The gyro 1 adapted for freedom in three planes may have adjustable latitude weight 6<1>, and a cage 7 for locking the gyroscope when not in use or for centralizing it when it is desired to change course. The cage 7 is normally held by a spring 9 but is freed by the solenoid 10. On the stem 12 projecting from the vertical ring 3 is a trolley 11 adapted to contact with spaced annular contacts 13, 14 connected by windings 14<1>, 15<1> with a servomotor, in this case a wind-driven motor 16. Upon excitation of one of the windings the shaft 18 of the motor is clutched to the drum 19 suitably connected to the rudder tiller 20. From this drum also follow-up connections 21 are passed back to the annular member 22 carrying the contacts. For correcting wander, solenoids 23, 24 are fixed to the vertical ring 3 and on the casing are soft iron plungers 25, 25<1> whereby on alteration of E.M.F. the torque is applied to the axis of the gyroscope. The windings of the solenoids are directly controlled from the amplified output of an earth inductor compass 26, the angularly disposed windings 27, 27<1> of which are rotatable on a vertical axis in the earth's magnetic field by a wind motor 28. Current is taken from the commutator 29 by brushes 30, 301 carried by an annular worm gear 32 adjustable by a hand-crank 35. The relative amount of current collected by the brushes depends upon their position in azimuth so that by movement of the crank 35 redistribution of balance may be effected. The output may be led to an indicator 39, the index 39<1> of which will indicate craft deviation. For rapid adjustment of the gyro, a switch 43 is provided in the circuit of the amplifier 42 and solenoid coils 23, 24. For changing the course, a contact 47 is opened and the gyro thus caged and held stationary whereupon the ship is brought to the new course by direct operation of the rudder gear. Upon reaching the desired course the handle 35 is moved until the indicator 39 reads to zero, then the gyro is freed by closing the switch 47. In a modification a standard magnetic compass is employed and the adjusting crank 35 applied to its carrier. A ring on the compass has condenser plates 81, 81<1> co-operating with plates 82, 82<1> on the magnetic element and the condenser thus formed is placed in the oscillatory circuit exciting the solenoids 23, 24. The condenser plates are in a tuned circuit including transformer 82 and valves 83, the output of the valve being connected to a relay coil 84 which pulls a biased relay armature 86 against contacts 88 which is normally held by a spring against a contact 87. The contacts are in the solenoid circuit. The gear 80 of the crank 35<11> also operates the contact ring 89 carrying the segments 13, 14. In this case to change the course the crank 35<11> only has to be moved. When the earth inductor has a single winding 27<11>, the A.C. output therefrom is led through an amplifying system to a three-phase motor 94 and the leads are connected so that as an E.M.F. is built up in one or other direction the motor applies a corresponding torque to the gyro. In place of shifting the compass brushes, the lines of force may be varied by moving a frame 102 carrying high permeability polepieces 100, 101. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a correction for the gyro by a magnetic compass wherein torque is not applied. The case 50, Fig. 2 (Cancelled), of the compass contains a conducting liquid and plates 53, 54, one set of which is fixed to the casing and the other to a movable element of the compass. The varying resistance between the plates in conjunction with resistances R1, R2, R3 controls one winding 57 of a two-phase reversible motor 55. To correct the gyro, the motor 65 drives, through a reduction and differential gear 63, 65, the ring carrying the contact segments 13, 14 and moves them with reference to the contact 11. This subject-matter does not appear in the Specification as accepted.