| 摘要 |
<p>The hydraulic device for controlling a piloting pressure (18) comprises a two-way valve (2) located on a hydraulic piloting conduit (17) which provides a piloting pressure to a controlling overcentre valve (16). The piloting pressure is taken from a delivery branch (15) of a hydraulic actuator (9) during a load lowering phase (12). The two-way valve (2) is normally open and is closed by effect of a predetermined pressure on the delivery branch (15). An adjustable choke (19) is arranged in parallel to the two-way valve (2) on an auxiliary by-pass conduit (20). The device enables a rapid and progressive activation of the hydraulic actuator (9) during the load lowering phase. <IMAGE></p> |
