| 摘要 |
<p>The hydraulic cylinder controls the width of furrows, produced by reversible ploughs and has a variable but repeatable stroke. The fixed piston head has an hydraulic fluid supply port which feeds the cavity above the mobile piston. A second piston is mounted on the hydraulic ram and acts on a shackle fitting. A cavity is formed between the mobile piston and the ram piston and is connected to the hydraulic system via a drilling and connection port. - To control the piston stroke the cavity is pressurised to displace the ram to the required starting position. The port is then sealed and the two pistons plus the trapped hydraulic fluid in the cavity act as a single piston under hydraulic pressure applied either via one of the ports.</p> |
