| 摘要 |
<p>A valve includes a body with a spool bore, a supply passage, a tank passage, and a workport. A spool, in the spool bore, has a first position providing a first path between the supply passage and the workport, a second position providing a second path between the tank passage and the workport, and a closed position. A latch assembly includes a cam that moves in response to pressure, a sphere engaged by the cam, and a notch. While the spool is in the second position, fluid flowing from the workport to the tank passage produces a first pressure, which causes the cam to hold the sphere in the notch, thereby inhibiting spool movement; and when the fluid flow from the workport to the tank passage terminates, a second pressure is produced causing the cam allow the sphere to move out of the notch, thereby enabling the spool movement.</p> |
