Hydraulic pressure regulating system for rolling mills or the like

Claim 1

IN A HYDRAULIC PRESSURE REGULATING SYSTEM FOR ROLLS IN A ROLLING MILL STAND OR THE LIKE, APPARATUS COMPRISING, IN COMBINATION, AT LEAST ONE PRESSURE CYLINDER IN SAID STAND, A PISTON IN SAID PRESSURE CYLINDER TO EXERT A SELECTED ROLLING FORCE, MEANS FOR PUMPING HYDRAULIC LIQUID AT A SELECTED POSITIONING PRESSURE INTO SAID PRESSURE CYLINDER TO RAISE SAID PISTON A SELECTED AMOUNT, VALVE MEANS CONNECTED TO SAID PRESSURE CYLINDER AND ADAPTED WHEN CLOSED TO HOLD SAID PISTON GENERALLY IN SAID RAISED POSITION, A MAINTAINER CYLINDER IN COMMUNICATION WITH SAID PRESSURE CYLINDER THROUGH SAID VALVE MEANS, A PLUNGER IN SAID MAINTAINER CYLINDER, COUNTERWEIGHT AND BEAM MEANS TO EXERT A LEVER FORCE UPON SAID PLUNGER TO PROVIDE A PRESSURE AT LEAST AS HIGH AS SAID FIRST-NAMED PRESSURE AND SAID SELECTING ROLLING FORCE AND, FURTHER, TO FEED LIQUID IN SAID MAINTAINER CYLINER INCREMENTALLY TOWARD SAID PRESSURE CYLINDER TO MAINTAIN THE SAME WITHOUT LETDOWN, MEANS RESPONSIVE TO A SELECTED AMOUNT OF MOVEMENT OF SAID PLUNGER DUE TO DISCHARGE OF LIQUID FROM SAID MAINTAINER CYLINDER IN SAID INCREMENTAL FEED TO CUT OFF SAID COMMUNICATION BETWEEN SAID MAINTAINER CYLINDER AND SAID PRESSURE CYLINDER WITHOUT RELEASE OF PRESSURE IN SAID PRESSURE CYLINDER, MEANS RESPONSIVE TO WITHDRAW SAID PLUNGER RELATIVE TO SAID MAINTAINER CYLINDER AND SUCH LAST-NAMED MEANS TO REFILL SAID MAINTAINER CYLINDER, AND MEANS RESPONSIVE TO MOVEMENT OF SAID PLUNGER RELATIVE TO SAID MAINTAINER CYLINDER DUE TO SAID REFILLING TO REESTABLISH SAID COMMUNICATION UPON COMPLETION OF SAID REFILLING.