| 摘要 |
<p>A hydraulic valve system uses spool type pilot valves with the valve openings notched to provide non-linear response to movement of pilot valves. A servo type valve with a four-way spring centered spool is operated either manually or hydraulically by the spool pilot valve. A limit stop is located at each end of the servo spool valve. The notching geometry in the spools of both the pilot valve and servo valve provide a nonlinear response such that controllability and safety are improved, without hysteresis. The system has a manual override on both ends of the cervo valve which is operated independently of the pilot spool valve. The system is proposed for use on articulated serial towers which consist of a mobile platform, a rotatable mounting for a lower boom, and upper boom having an articulated mounting on the lower boom, and personnel or tool carrying basket at the outer end of the upper boom.</p> |
