Patent GB-153589-A (GB)
Title: Improvements relating to gyroscopic compasses
IPC: G01C19/38
Filed: 1920-11-08
Abstract: 153,589. Sperry Gyroscope Co., (Assignees of Sperry, E. A.). Nov. 8, 1919, [Convention date]. Gyroscopic compasses.-Relates more particularly to compasses of the kind described in Specification 135,500 in which the orienting movement is obtained by the movement of liquid between containers mounted on opposite sides of the gyro-casing, and consists essentially in providing damping-means responsive to the movement of the liquid to produce a torque around the vertical axis by power taken from the rotor. Means for suspending the gyroscope and for operating a follow-up support for the sensitive element are also described. The gyro-casing 11 is mounted on horizontal pivots 9 in a vertical ring 8. The rotor rotates counter-earthwise and the casing 11 and attached parts are preferably substantially balanced about the axis 9. The liquid-containers 15, 16 are mounted on annular platforms 17 secured to the casing 11 and are connected by a pipe 19 having a restriction 20 which is adjustable by a set-screw 21. The damping-means are rendered operative when the gyro-axis becomes inclined to a base-line represented by the level of the liquid in the containers. In each container is a float 25, the stem 26 of which is connected by an arm 27 to a ring 28 extending around the casing 11 and pivoted to the platform 17, so that tilting of the casing causes relative movement of the ring and platform. To magnify this movement, each side of the ring is connected to the short arm 30, Figs. 1 and 4, of a bell-crank lever 31 pivoted to a bracket 41 carried by the platform 17, the longer arm of the lever extending downwards with its straight edge 32 adjacent an aperture 33 to which an air blast is led 'by a pipe 36 from the casing 11. Thus when the casing tilts, the reactions from the air jets become unequal and a damping torque is set up around the axis of orientation. The pipes 36 may be connected by an equalizing pipe 39. To adjust the levers 31 so that the reactions from the air jets are normally equal, the bracket 41 is carried by a nut 44 engaging with a screw 43 which can be turned by a milled head 42. The suspension-means shown in Figs. 1 and 8 comprise a preferably cupped support 2 carried by the inner ring 3 of the gimbal mounting and containing a hardened steel ball 1. Another cupped member 6 bearing on the ball is carried bv a support 7 secured to the ring 8. Current is supplied to the rotor from the follow-up element by fingers 91 passing into cups 90 carried by the member 3, which may be operated by a follow-up device comprising a pair of reversing contacts 50, 51, Figs. 5 and 10, secured to the member 3 from which they are preferably insulated, connexion being effected by plugs 52, 53. The bracket 54 supporting the contact-blocks carries a rotary pintle 57 on which is mounted an arm 58 to which is secured a trolly 59 rotatably mounted on a flat spring 60. The relative movement between the support 3 and frame 8 is imparted to the trolly by a pin 61 passing between arms 62, 63, Fig. 2, secured to the frame. The contacts 50, 51 are connected to the opposite field windings 84<1>, 84<11> of a reversible motor 84. The support 5 carries a stem 80 having radial arms 81 which support the card &c. and a gear wheel driven by the motor 84. The whole frame is rotatably mounted and suspended from a long bearing under a stationary cap. Reference has been directed by the Comptroller to Specifications 166,570 and 166,571.