| 摘要 |
1,153,234. Valves. VAPOR CORP. 17 Oct., 1967 [24 Jan., 1967], No. 47176/67. Heading F2V. A valve for controlling the flow of high pressure fluid and adapted to have a fully closed, intermediate, and fully open state, comprises a housing 12 having disposed therein, and between an inlet 16 and outlet 26, a chamber 28, the chamber being defined by a conical wall portion 31, a cylindrical wall portion 30 and a piston 38 which is slidable within the cylindrical portion. The piston is biased by a spring 54 and fluid pressure within the chamber, which pressure is derived from the inlet via a restriction 32, into a position in which an extension 40 formed integrally therewith engages a seat 24 so closing the valve. Upon actuation of a solenoid operated valve 58, the chamber pressure is partially relieved via passage 56 so permitting the inlet pressure to move the piston into the chamber, the degree of movement being limited by a piston stem 48 which eventually obturates passage 56 and so serves to retain the valve in its intermediate position (Fig. 2, not shown). To bring the valve into its fully open state, a second solenoid valve 64 is actuated so permitting the chamber pressure to be fully relieved and the piston to move further into the chamber until it abuts a stop formed by the stem housing 46 (Fig. 3, not shown). In a modification, the cylinder may be vented to a point downstream of the outlet rather than to atmosphere. |
