GB513911A - Improvements relating to directional gyroscopes - Google Patents

Abstract

513,911. Fluid-pressure servomotor-control systems. ALKAN, R. March 24, 1938, No. 9026. Convention date, June 9, 1937. [Class 135] A directional gyroscope comprises a differential fluid-pressure relay coaxially arranged within a follow-up member and consisting of a fluid circuit divided into two parts by a deformable membrane and actuated in a manner known per se by means adapted to form a sort of pneumatic or hydraulic Wheatstone bridge, the deformable membrane being integral with the follow-up member controlled by the gyroscope and which is located coaxially with the axis of rotation of the gyroscope support. A gyroscope 1 has a differential fluid-pressure relay 25 arranged within a member 9 which follows up the movements of the gyroscope relative to its support and is actuated by a servomotor 10 the control or distributing valve 15 of which is actuated by the relay 25. The rotor 1 of the gyroscope is free to rotate about perpendicular axes 2, 3, 4 in a frame 5. The latter has a depending skirt or drum 6 with cut-away edges 7, adapted to obturate. differentially slits 8, 8<1> in the follow-up member 9 also formed as a drum. The slits 8, 8<1> communicate through cavities 27 and passages 26 with chambers 23, 24 on opposite sides of a flexible membrane 25 which constitutes the effective member of the relay. The membrane 25 is connected to a rod 28 passing through a gland in a trunnion on the follow-up member. A thrust bearing 29 on the rod 28 is engaged by a lever 31 connected to the piston valve 15 by a rod 16. The servomotor 10 operates a shaft 11 through reducing gear, the shaft 11 driving the follow-up member 9 through a pinion 12 and a crown wheel 13. The chambers 23, 24 also communicate through fixed orifices 21, 22 with a conduit 20 by which compressed air is supplied to the driving nozzle 34 of the rotor. The conduit 20 communicates by means of a cavity 19 and a rotatable union with a fixed supply pipe 17. To avoid " hunting," the transmission between the relay 25 and the valve 15 is provided with a spring 33. As shown this operates on the rod 16, so that a certain free movement of the drum 6 or dead space occurs before the member 9 follows this movement. By extending the shaft 11 of the servomotor 10, a drive may be obtained for various instruments which will follow the orientation of the gyroscope.