GB540211A - Improvements in fluid-actuated servomotor systems - Google Patents

Abstract

540,211. Fluid-pressure servomotor-control systems. SMITH & SONS (MOTOR ACCESSORIES), Ltd., S., and MEREDITH, F. W. Jan. 5, 1940, No. 342. [Class 135] A servomotor control system comprises a plurality of double acting power cylinders connected in series with one another between the controlling ports of the valve controller by a single chain of conduits and a follow-up connection between one only of the power pistons and the valve controller. The Figure shows the invention applied to the simultaneous control of a bomb sight and the elevator or ailerons of an aircraft by a gyro-vertical. The inner gimbal ring supporting a rotor spinning in a vertical axis is connected by a floating lever 21 and links 20, 22 to a control valve adapted to connect ports 15, 16 alternately to pressure and exhaust. The port 15 is connected to one side 38 of a power piston 33 adapted to act through a lever 34 and link 36 to adjust a bomb-sight. The port 16 is connected to one side 37 of a similar power piston 26 adapted to act through a lever 27 and link 29 to adjust the elevator or ailerons of the aircraft. The other side 37<SP>1</SP> of the piston 33 is connected by a pipe 39 with the other side of the piston 26 so that when one piston is displaced by fluid pressure a corresponding amount of liquid is displaced from one cylinder to the other. A follow-up connection to the floating lever 21 is provided by an extension 40 on the lever 34 which is urged towards a central position by adjustable springs 42. To facilitate movement of the piston under the action of these springs a restricted by-pass connection 41 is provided across the piston 33. The second piston 33 may be used solely for providing the follow-up action.