| 摘要 |
<p>A hydraulic control valve for controlling flow between a pump, a hydraulic device, and a vessel containing hydraulic fluid. The control valve has an elongated valve slide which is slidably mounted in an elongated valve housing. The valve has three positions, a central neutral position, a float position axially offset in one direction from the neutral position and a constant pressure position axially offset in the opposite direction from the neutral position. In the neutral position, flow of hydraulic fluid to the hydraulic device is inhibited. In the float position, connection is such that a raised device, such as a hydraulically operated bucket, is lowered slowly by gravity until it rests on the ground or another object. In the constant pressure position, the valve connects pump pressure to the load sensing circuit to facilitate, for example, shaking of a bucket of a piece of earth moving equipment.</p> |
