| 摘要 |
<p>A valve construction for high pressure gases, allowing rapid opening and closing, includes a main body with inlet and outlet passages, and a guide sl eevehaving a primary and a secondary piston slidably mou nted within the sleeve, the primary piston being adjacent a closure at one end of the sleeve, and the se condary piston being at the end of the primary piston which is remote from the closu re. The secondary piston supports a seal for closing the gas outlet passage when the secondary piston is remote from the closure. The secondary piston has an axial passag e with an elongate member movable therein, the elongate member being fixed to the p rimary piston. A valve means is provided between the axial passage and the elong ate member, the valve means being open when the bleed orifice is closed. A peri pheral seal between the secondary piston and the sleeve acts to restrain the axial movement of gas. An access passage connects the periphery of the secondary piston w ith a location on the axial passage, while a passageway in the secondary piston c onnects the region between the first and second pistons with the bleed orifice chamb er. An electrical coil acts to generate a magnetic field. The valve construction thus defined is in equilibrium when the coil is de-energized, the seal means closing the gas outlet passage, the closure portion closing the bleed orifice, and the primary pist on being furthest remote from the closure. When the coil is energized, the primary piston moves toward the closure until the valve means closes, lifting the closure p ortion off the bleed orifice and permitting gas to escape from around the primary piston, through said passageway, and out the bleed orifice, thus resulting in an inc rease in the pressure differential across the peripheral seal.</p> |
