| 摘要 |
<p>1,036,219. Valves. SOC. INDUSTRIELLE GENERALLE DE MECANIQUE APPLIQUEE S.I.G.M.A. Sept. 12, 1963 [Sept. 29, 1962], No. 35930/63. Heading F2V. The movement of an oscillating motor or, as shown, a ram 9 is controlled by a rotary or, as shown, a three-position sliding-valve 13, the lines 7, 8 to each side of the ram 9 embodying a safety valve 14, 14a, which valves seat at opposite ends of a duct 25 leading to a reservoir 6 and separate that duct from passages 27, 27a leading to the lines 7, 8. When the valve 13 is moved from an end to the central position shown the supply pump 4 is cut-off from both sides of the ram, but should the latter continue to move a positive pressure will be built up on the side of the ram previously connected to the reservoir and a reduced pressure will result on the opposite side of the ram. If the positive pressure occurs at the underside of the ram then it appears in the passage 27 and acts on a plunger 16 slidable in the valve 14 to close an orifice 23 through a piston 17 and so isolate chambers 18, 20 the former being open to the reservoir 6 via a duct 19, and the latter being connected to passage 27 by a channel 21; pressure in the chamber 20 then moves the piston 17 to the right to compress a spring 22 which loads the valve 14. Should the positive pressure then increase beyong a given level the valve 14 opens to connect the passage 27 with the duct 25. The reduced pressure in passage 27a causes the components of safety valve 14a to occupy the positions shown so that should the pressure reduce beyond a given level that valve will open and passage 27a will receive fluid from duct 25. If, in normal operation, the ram is forced by the load connected thereto to move faster than the resulting space can be filled by the pump 4, then the respective safety valve opens to enable additional fluid to be drawn from the reservoir.</p> |
