Patent GB-493408-A (GB)
Title: Improvements relating to remote control systems
IPC: F15B9/14
Filed: 1937-12-10
Abstract: 493,408. Fluid-pressure servomotorcontrol systems. SPERRY GYROSCOPE CO., Inc. Dec. 10, 1937, No. 34255. Convention date, Dec. 16, 1936. [Class 135] A pneumatically operated repeating system comprises a sending instrument having relatively rotatable ported and shutter members, the shutters and ports being so designed that the amount of port area covered by the shutters varies with the relative angular positions of the ports and shutters and a receiving instrument having substantially similar ported and shutter members. A common means is provided for drawing air through the ports of both sending and receiving instruments and means responsive to the difference between the pressure drops due to the obturating effects of the respective shutters are adapted to cause rotation of a ported or shutter member at the receiving instrument until said member is in correspondence with the similar member of the sending instrument. In the form shown in the Figure the control valve actuated by a magnetic compass or directional gyroscope comprises an inner member 4 with a spiral contour adapted to co-operate with a single radial port 11 and an annular member 5 with a notch having one radial side and the other slanting or spiral shaped adapted to co-operate successively with a series of radial ports 10. The port 11 leads to a central chamber connected by a pipe 20 with a bellows 29<1>, while the ports 10 lead to an annular chamber connected by a pipe 21 with a bellows 32. A similar valve at the receiving station communicates by pipes 20<1>, 21<1> with bellows 29, 32<1>. The bellows 29, 29<1> are coupled to a pivoted jet 26 adapted to deliver air through shoots 28, 28<1> to rotate a turbine 24 in one direction or the other. A similar jet is operated by the bellows 32, 32<1>. Air is continuously withdrawn from the pipes 20, 20<1>, 21, 21<1> and bellows 29, 29<1>, 32, 32<1> through fixed restrictions 30, 30<1>, adjustable restrictions 33, 33<1> and pipes 36. When the transmitting valve is moved the balance of pressure in the two pairs of bellows is disturbed and the jets are moved to cause the rotation of the turbine in the appropriate direction that acting through toothed reduction gearing 23<1>, 22 it rotates the receiving station valve to a corresponding position. When this valve reaches the position corresponding to that of the valve at the sending station the pressure balances are restored and the jets moved to the neutral position. A valve 39 included in the supply pipe to the jet 25 is connected by links and a bell-crank lever to the jet 26 so that the jet 25 only comes into operation when the jet 26 nears its neutral position. In a modification in which the sender valve is actuated by a hand crank two reversely acting turbines are coupled to the receiving station valve by skew and worm gearing. The turbines are controlled by two pairs of jets one jet of each pair being directly connected to the valve at the sending station while the other jets are connected to the valve at the receiving station. The pair of jets controlled by the inner part of the valve are made larger than the other pair so that the former have the preponderating effect.