Hydraulic valve control system for a platform for lifting persons

摘要

The subject-matter of the application relates to a hydraulic valve control system for a platform for lifting persons, which is arranged on a cantilever bracket. For different sequences of movement, the bracket is controlled via hydraulic drives. A hydraulic pump supplies these drives via series-connected directional control valves which have at least one bypass with a control valve placed ahead of them. The intention is to improve a control system of this type in that a proportional control of the bypass via the control valve is provided, which control has priority over the triggering of the directional control valve. This is achieved by the fact that the control valve in the bypass is positively controlled by a proportional actuating member via which, in its activated state, the directional control valves are at the same time locked.