| 摘要 |
<p>A controller for a spring wing on a frog that utilizes a floating piston rod carrying a fixed piston valve and a free-moving piston head is provided. When the piston rod is actuated by the opening movement of the spring wing, the piston valve separates from the piston head briefly, allowing oil to flow through the piston head in a relatively unrestricted manner. The piston head is spring biased towards the piston valve; upon contact between the piston head and the piston valve, the oil flow through the piston head stops, helping to hold the spring wing in the open position. When the spring wing begins to close, the adjustable oil flow through the controller allows the piston rod to move at a controlled rate, thereby controlling the closure rate of the spring wing.</p> |
