GB331972A - Improvements in gyroscopic compasses - Google Patents

Abstract

331,972. Berglund, G. H. F. May 2, 1929. Gyroscopic compasses.-Two gyroscopes having their axes inclined at substantially equal but opposite angles to the vertical are mounted independently in gimbal rings within a frame which is rotatable about a vertical axis, the frame being rotated by a servo-motor which becomes operative when the plane containing the axes of rotation of the gyroscopes does not coincide with the plane of the frame, so that the said planes are caused to coincide with each other and with the meridian plane. The receptacle 1 mounted in gimbal rings on the ship, &c. carries the frame 2 which is rotatable about a vertical pivot 3. The gyroscopes 10, 11 are pendulously mounted on horizontal pivots 12, 13 and 14, 15 respectively in horizontal gimbal rings 4, 5 supported on horizontal pivots 6, 7 and 8, 9 in the frame 2. Movement of the gyroscopes relatively to the frame about the pivots 6, 7 and 8, 9 brings into operation a contact device 26 which causes a motor 24 to rotate in one direction or the other and, through the gearing 25, to rotate the frame about the axis 3 until its plane coincides with that containing the axes of rotation of the gyroscopes. The contact device 26 comprises a magnet 126, Fig. 6, carried by an arm 4<1> attached to the ring 4 and acting on a pivoted contact member 127 mounted within an hermetically-sealed box 128 and extending between stationary contacts 129, 130, the box 128 being carried by an arm 5<1> attached to the ring 5. The compass-card 58 is carried by the frame 2. The receptacle 1 contains oil, &c. to support the weight of the gyroscopes, and is stabilized by a gyroscope 37. In order to apply the required torques to this gyroscope to maintain the frame 2 in a vertical plane there is provided between the gyroscopes 10, 11 a T- shaped member 29 capable of turning about its longitudinal axis in a support 30 which can turn about an axis 31 with respect to the frame. The ends of the cross part of the member 29 extend into grooves in members 33, 34 extending from the gyroscopes 10, 11 respectively so that the length of the member 29 lies along a horizontal line bisecting the angle between the axes of the gyroscopes. The extremity of the member 29. carries a contact device 36 of the kind shown in Fig. 6 co-operating with a movable contact on the frame 2. A similar contact means 35 is provided between the frame and the horizontal axis 14, 15. These contact devices control motors 38, 39 the rotation of which is arranged to displace masses 40, 41 to apply .the righting-torques to the gyroscope 37. To reduce friction in the cardan suspension of the receptacle 1 the pivot pins 60, 61, 63, 64 are arranged to be continuously rotated the directions of rotation of the pins 60, 63 being opposite to those of the pins 61, 64 respectively. The current for rotating the gyroscope and for operating the motors &c. is introduced through a distributor 19. Specification 331,956 is referred to.