| 摘要 |
<p>the hydraulic automatic switch (1) acting between a pump and a pressure vessel to maintain the pressure therein between two specific limits. It comprises a check valve in the duct (7) to the vessel, and a return line from upstream of this valve to the pump suction. A piston valve (27) is spring-loaded (46) on one side and pressure-loaded from downstream of the check valve on the other, and controls opening and closing of the return line. A disc spring (4a) connected to the valve piston (27) provides rapid bi-stable action thereof. The Young's modulus of this disc (19) is below 10,000 da N/m2 and the yield point is as high as this condition permits.</p> |
