Equalized hydraulic clamp force control

摘要: Hydraulic valve circuitry adapted for automatic weight-responsive control of load-clamping members a load-lifting system having free lift mast. The generally includes one or more fluid power actuator (101, 103) applying gripping force to load, at least elongate, longitudinally-extensible lifting device (154, 156) range motion and main motion, manually operated selector valves (134, 146). hydraulic provides, independently, the load- clamping when full-time without concurrent manual actuation valves, equalization sensed load weight so that is substantially independent position device.