Hydraulic cylinder pressure control procedure for screw ratchet drives, compares measured load stroke pressure versus time variations with threshold

摘要

A hydraulic cylinder (10) pressure control procedure measures the pressure variation over time intervals and stops the working cycle when the rise in pressure for an increase in load is found to be smaller than a threshold value by comparing it with previous increases. Includes an Independent claim for equipment implementing the procedure using a pressure source (20) with changeover valve (19), pressure sensor (22) and control unit (21).