| 摘要 |
1,243,054. Valves. ROTAX Ltd. 6 Jan., 1969 [22 Jan., 1968], No. 3223/68. Heading F2V. [Also in Division G3] A fluid flow control valve comprises a housing having an enlarged portion 11 intermediate its ends, a hollow body 13 within the enlarged portion and having a closed end 15 and an open end, a piston 16 slidable within the hollow body and having an integral skirt 17 slidable within the housing, a seating 23 at the open end of the hollow body, a valve element 22 intermediate the ends of the skirt for co-operation with the seating, a flow aperture 24 in the skirt, and means for causing movement of the piston within the hollow body between a closed position in which the flow aperture lies within the body and an open position in which the flow aperture is exposed beyond the body. Pressure from the upstream side of the valve 8 is admitted through a solenoid-actuated valve 26 and a restriction 27 to a space 25 to displace the piston 16 to the right and open the valve. If the solenoid valve is operated to connect the space 25 to atmosphere, pressure at the outlet 9 acting on the piston 16 and at the inlet 8 on the annular area between the reduced portion of the skirt 17 and the valve element 22 causes the valve to close. A change-over valve 28 permits the inlet and outlet 8, 9 to be reversed and also maintains the valve open if the pressure drop is reversed. The piston 16 may be spring-biased towards either the open or closed position of the valve which may be used to control the downstream pressure by connecting the space 25 with the end 8 of the housing through a pressure regulator. The valve may be used to control the air flow to a pressurized aircraft cabin. |
