| 摘要 |
<p>904,121. Fluid-pressure servomotor-control systems. GARRETT CORPORATION. Jan. 9, 1959 [Jan. 9, 1958], No. 926/59. Addition to 850,374. Class 135. A pneumatic control system for controlling fluid flow through a cooling turbine 14 to aircraft cabin 10 comprises a differential pressure regulator 24 supplied at 26 with a diaphragm 40 subject differentially to the low ambient and higher regulated pressures, a pair of orifices 32, 34 connected in series between the regulated and ambient pressures, and means responsive differentially to the control pressure between the orifices and the cabin pressure for controlling the fluid flow. The means comprise a spring-loaded diaphragm assembly 54, 58, rigidly connected to relay valve 66 co-operating with seat 75 moved by multiplying levers 98, 100 in accord with the movements of diaphragm power device 94 controlling the nozzle opening 18. Upstream orifice 32 is choked throughout its range of operation whereas downstream orifice 34 is only choked above a predetermined altitude, so that cabin pressure is directly proportional to altitude up to a certain height after which the cabin pressure reduces at a rate less than that of ambient pressure. Diaphragm 54 is subject to the control pressure via 36 and the cabin pressure via 37 and orifice 62. Large cabin pressure fluctuations act initially on large diaphragm 58 before the pressures equalize through orifice 62. Movement of relay valve 66 allows more or less fluid from regulator pipe 53 leaking across power device 94 to escape to atmosphere via passage 82 so that the power device follows up the movement of the relay valve.</p> |
