| 摘要 |
<p>"COMPOSITE PNEUMATIC-HYDRAULIC SYSTEM IN A DOCKLEVELLER INSTALLATION" A dockleveller installation is provided having a dockboard hinged for pivotal movement and a composite pneumatic-hydraulic system for pivoting the dockboard. The composite system includes a fluid-filled cylinder attached to the dockboard, a pressurized air supply, and a multiplier connected therebetween. The multiplier is a closed cylindrical member comprising an air cylinder segment connected to the air supply and a fluid cylinder segment connected to the hydraulic cylinder. The interior crosssectional area of the air segment is greater than that of the fluid segment. The multiplier also includes a double headed piston, one end of which reciprocates and seals in the air segment, the other end of which reciprocates and seals in the fluid segment. This composite system enables pressure to be transferred through the multiplier from the air supply to the hydraulic cylinder, causing the cylinder to open and the dockboard to pivot. The pressure transferred from the air to the fluid is increased by an amount proportional to the ratio of the piston head diameters.</p> |
