Patent GB-137059-A (GB)
Title: Improvements in gyroscopic compasses
IPC: G01C19/38
Filed: 1919-12-24
Abstract: 137,059. Sperry Gyroscope Co., (Assignees of Tanner, H. L., and Thompson, H. H.). May 27, 1915, [Convention date]. Gyroscopic compasses are made with a gyro top-heavy instead of pendulous. The direction of rotation is made counter-earthwise to obtain a naturally meridian-seeking gyro; or, if the rotation is earthwise, means are provided for producing a torque to make it meridian-seeking whenever deviation occurs. Combinations are described of two gyroscopes mounted in a common frame and co-operating to orientate said frame, the general arrangement and certain constructional details being similar to those described in Specification 100,490; a single-gyro compass of the Sperry type is also described. In the construction shown in Fig. 3, both gyros are meridianseeking, one 14' being pendulous and rotating earthwise, and the other 13<1> being top-heavy and rotating counter-earthwise. Any torque about the vertical axis of the main frame 2 will cause precession in opposite directions about the horizontal axes of the gyros; the contact system 17, 18, 20, shown in Fig. 6, then operates to bring into action in the appropriate direction the reversing motor 30 geared to the frame 2. Damping is effected by the application of torques about the vertical axes by means of electro-magnetic devices 35, 36, shown in Fig. 9 and previously described in Specification 100,490, under the control of contacts on an arm 25 of the vertical ring 9<1> and on the frame 2 respectively. Alternatively, a contact system 37, 38, 39, Fig. 4b, mounted on the gyro casing and its vertical ring 9' may be employed. Another arrangement of compass, shown in Fig. 2, comprises an ordinary pendulous gyro 14" rotating earthwise, and a top heavy gyro 13<11> also rotating earthwise; the latter is made meridian-seeking by means of the torque-producing reversing motor 100 on its horizontal axle and controlled by the contact-system 23<1>, 26' responsive to movements in azimuth of the gyro 14<11> in the frame 2. - The gyros are caused to act together and keep in the same plane by a reversing motor 30' geared to the vertical ring 10" and controlled by the contact system 17, 20 responsive to relative movements of the gyros about their horizontal axes. In the preferred form of the invention shown in Fig. 1, both gyros are top-heavy but rotate in opposite directions. Motor 30, controlled by contacts 17-20. acts as it does in the construction shown in Fig. 3. Damping is effected by applying a positive torque about the vertical axis of each gyro in the direction of the precession. This may be effected by shaping the contacts 23, 24, as shown in Fig. 7, so that the spring-pressed trolly 26 will exert a torque on the arm 25 tending to turn the frames 9 and 10 further when the trolly is slightly displaced from its central position. An indicator for showing the relative position of the gyros with respect to the main frame 2 is shown in Fig. 4; a window with cross-wire 72 is formed in the frame 2 for viewing a marker 71 on the frame 9. A single gyro form of Sperry type with gyro rotating counter-earth wise is shown in Fig. 8. The bail 66 is arranged above its horizontal pivots and engages a pin 67 on the upper side of the gyro casing.