Universal control system for hydraulic cylinders

摘要

A universal control system for hydraulic cylinders to enable controlled increments of movement for varying uses including shaping members and lifting and lowering of loads. The lift control system is utilized to synchronize the raising or lowering of a load by, for example, four simultaneously-acting pump-operated hydraulic rams which have plural increments of movement. A sensor associated with the load adjacent each ram measures incremental movement of the load. A master controller controls the operation of the rams in accordance with the sensed increments and operates each pump simultaneously and independently until each pump achieves a preselected increment of movement of a ram, to maintain the load substantially level, followed by movement of all the rams through another increment of movement until the total lifting or lowering movement is achieved.