Patent GB-107572-A (GB)
Title: Improvements in Gyroscopic Compasses.
Inventor: TANNER HARRY LAURENCE
IPC: G01C19/38
Filed: 1916-10-24
Abstract: 107,572. Tanner, H. L. June 28, 1916, [Convention date]. Gyroscopic compasses.-Relates to improvements upon the compass described in Specification 100,490, in which the medium-seeking action is obtained by the co-operation of two oppositely-acting gyroscopes. The gyroscopes are so interconnected that they incline in opposite directions. The gyroscopes are mounted to turn about vertical axes in a frame itself adaptecl to turn about a vertical axis, means responsive to relative movement of the gyroscopes about their individual vertical axes being employed to exert a torque about the vertical axis of the frame to bring it into the meridian if displaced therefrom. In the construction shown in Fig. 1 two oppositely-rotating gyroscopes are carried by a main frame 30 supported by a vertical stem 13 mounted in ball-bearings upon a spider 10 carried in gimbals. The vertical rings 28, 29 of the gyroscopes are connected by a universal coupling comprising a bracket 45 on the ring 28 carrying a ball 47, which engages a slot in the form of a fork 48 in the lower end of a bracket 46 on the ring 29. The torque required to return the frame 30 to the meridian when displaced therefrom is exerted by means of an electric motor 22 geared to a gear-wheel 21 on the frame 30, the movements of the motor being controlled by means of reversing contacts 50 and a trolly 52 carried by the rings 28, 29 respectively. Damping of the oscillations of the compass about the meridian is produced by the torque of the wires 34, adjustably supported as shown in Fig. 2, by which the gyroscope vertical rings are suspended from the frame 30. Damping of the oscillations of the gyroscopes with respect to the frame 30 is produced by means of a spring 55 secured at one end to a bracket 56 on the rotor casing 40 at a point in the vertical axis of the gyroscope. Another form of universal coupling for the gyroscopes is shown in Fig. 6. A bracket 45<1> on one gyroscope carries a pin 60 fitting loosely into a central hole in a block 61 journaled upon a vertical axle carried by a bracket 46 on the other gyroscope. A modified form of damping device, shown in Figs. 6 and 10, consists of a tension spring 67 connecting brackets 65, 66 on the two gyroscopes respectively. Another method of connecting the two gyroscopes is shown in Fig. 11. The vertical rings 28<1> and 29<1> carry intermeshing gears 70 and 71 respectively. The contacts controlling the motor 22<1> are mounted upon the rotor casings by means of brackets 72 and 73, the contacts preferably being placed out of line vertically with the line of contact of the gears 72, 73 so that the motor 22<1> will be actuated not only upon oscillations in opposite directions of the rotor frame about their horizontal axes but also upon opposite rotation about their vertical axes. Alternatively there may be a separate set of contacts to accomplish each function. Damping means comprise a spring 90 extending between brackets on the vertical rings 28', 29' and connected at its centre to a downwardly-extending arm 93 of a bell-crank lever 94 connected to dash-pots 96. Another method of damping consists in the employment of very thick oil in the bearings of the vertical rings.