Fecha de publicación: 06/11/1913 Fuente: WIPO "pollen" 7381. Pollen, A. H., and Isherwood, H. March 24. Gyroscopic apparatus. -Comprises improvements in the form of apparatus described in Specification 12,707/09. The platform it is desired to maintain in a constant angular position in space is operated from the central member 19 of a differential gear, the outer members 14, 15 of which are driven by oppositely rotating motors or magnetic clutches 12, 13. The supply of current to the motors or clutches is controlled by a gyroscope, the movement of which actuates a switch 5 which is returned to its normal position by the rotation of the shaft 21 operating the platform. The movement of the switch 5 varies the resistances in the armature circuits of the motors 12, 13 or the fields of the magnetic clutches. In modifications, the hunting contact surface is made cylindrical and is continuously rotated beneath the arm 5, and provides means for varying the resistance or of intermittingly operating the magnetic clutches in varying degree according to the position of the arm 5.