| 摘要 |
<p>DUAL SPEED HYDRAULIC PISTON ASSEMBLY Liquid fluid pressure applied to a piston causes advancement thereof at a rapid rate until an external resisting load applied to the piston rod exceeds a predetermined value producing a corresponding increase in the pressure within the opposing pressure chambers to which the piston is exposed. Bidirectional flow, conducted between the opposing chambers during rapid piston movement, is automatically blocked by a differential circuit pressure operated piston valve to cause a rapid increase in the differential pressures acting on the piston, and an increase in the value of the external piston rod load with a corresponding decrease in its rate of movement in the same direction. A modified embodiment permits the piston rod to act under pressure and with a force in both the extending and retracting phases of the stroke with the same rapid extending rate until the external resisting force is encountered.</p> |
