Patent GB-430886-A (GB)
Title: Improvements in or relating to gyroscopic stabilizers
IPC: F22B13/02
Filed: 1934-12-11
Abstract: 430,886. Brakes. SPERRY GYROSCOPE CO., Inc., Manhattan Bridge Plaza, Brooklyn, New York, U.S.A.-(Assignees of Walter, H., and Hodgkinson, F. P.) Dec. 11, 1934, No. 35591. Convention date, Jan. 19. [Class 103 (i)] [See also Group XX] In stabilizing-apparatus, particularly for diminishing rolling of ships, in which the precession of a heavy gyroscope is accelerated by an electric motor at the beginning of the roll and braked by a solenoid controlled brake at the end of the roll or when the gyro reaches the limit of its precession, the brake is spring applied and held disengaged, while the motor is energized by a pair of solenoid windings one being in series with the motor and the other being in shunt so that limited regenerative braking by the motor may occur without dragging the brake. The second solenoid winding may be separately excited but is reversed when the motor is reversed. As shown, the trunnions 2 on which the gyro 1 precesses are geared at 3, 4, 5 to a pinion 6 on the shaft 7 of the motor 8. Brake shoes 10, 101, pivoted at 12, 12<1> to the base plate 11 and pressed by springs 13, 13<1> on to a brake drum 9 on the spindle 7, may be withdrawn by a solenoid 14. Referring to the wiring circuit, Fig. 3, an auxiliary control gyroscope 25 at the beginning of a roll closes one or other of the contacts 26, 27 and energizes one of the coils 28, 29, (say 28). Thereupon the contacts 30, 31 are closed and the constant speed motor 32 (i.e. 8 in Fig. 1) having a separately excited field 33 is driven in the appropriate direction to accelerate the precession of the main gyroscope. The current to the motor 32 passes through the two windings 35, 36 of the solenoid 14, 35 being a heavy winding of few turns in series with the motor armature and 36 a fine winding of many turns in shunt with the motor armature. The current is sufficient to enable both windings together to hold the brake shoes withdrawn until the regenerated current due to the motor being over driven by excessive precession speed is sufficient to produce an opposing flux in the series coil 35 which with the springs will close the brake. The amount of braking will depend upon the amount of regenerative current so that the brakes will adjust themselves to maintain the speed of precession normal. A resistance 37 enables the amount of regeneration allowed before the brake is applied to be accurately controlled. When the main gyro 1 reaches the limit of its precession and operates one of the contacts 38, 39 by the cam 40 or when the roll and hence the auxiliary gyro contacts are reversed prior to the main gyro reaching a limit switch, the circuit through the coil 28 is broken, contacts 30, 31 open causing the brake to be applied in full, and back contact 32<1> is closed putting the motor 32 in circuit with a dynamic brake resister 34. In a modification, the motor armature 32 and series winding 35 are energized by an independently driven generator of which the field winding in parallel with the winding 36 is controlled by the contacts 30, 31, 30<1>, 31<1>. Two contacts controlled by a relay coil are provided to short circuit the armature 32 through a resistance when both contacts 26, 27 or one of contacts 38, 39 are open.