Compensated screwdown mechanism for a rolling mill

Claim 1

IN A ROLLING MILL HAVING A PREDETERMINED MILL SPRING, TWO ROLLS ROTATABLE ABOUT RESPECTIVE AXES FOR ROLLING A DEFORMABLE MATERIAL BETWEEN OPPOSITE FACES OF SAID ROLLS INTERMEDIATE THE RESPECTIVE END PORTIONS OF SAID ROLLS, FOUR BEARING MEANS RESPECTIVELY SUPPORTING SAID END PORTIONS, SAID BEARING MEANS CONSTITUTING TWO PAIRS, THE MEMBERS OF EACH PAIR SUPPORTING COORDINATED END PORTIONS OF RESPECTIVE ROLLS AND BEING MOVABLE TOWARD AND AWAY FROM ONE ANOTHER TRANSVERSELY OF SAID AXES, JACK MEANS COORDINATED TO EACH OF SAID PAIRS FOR NORMALLY URGING THE MEMBERS OF EACH PAIR OF BEARING MEANS TOWARD ONE ANOTHER, EACH JACK MEANS HAVING A CYLINDER ELEMENT AND A PISTON ELEMENT AXIALLY SLIDABLE IN SAID CYLINDER ELEMENT, SAID ELEMENTS BEING RESPECTIVELY CONNECTED TO THE MEMBERS OF THE COORDINATED PAIR FOR MOVEMENT THEREWITH AND DEFINING A PRESSURE SPACE IN SAID JACK MEANS, A SOURCE OF PRESSURE FLUID, VALVE MEANS MOVABLE FOR SELECTIVELY ADMITTING PRESSURE FLUID FROM SAID SOURCE TO SAID SPACE, AND FOR RELEASING SAID FLUID FROM THE LATTER, AND VALVE CONTROL MEANS, THE VALVE CONTROL MEANS OF EACH OF SAID JACK MEANS INCLUDING A FIRST CONTROL MEMBER MOVABLE IN RESPONSE TO THE PRESSURE IN SAID SPACE, AND A SECOND CONTROL MEMBER MOVABLE RELATIVE TO SAID FIRST CONTROL MEMBER, SAID SECOND CONTROL MEMBER BEING OPERATIVELY CONNECTED TO SAID PISTON ELEMENT FOR MOVEMENT IN RESPONSE TO THE MOVEMENT OF SAID PISTON ELEMENT IN SAID CYLINDER ELEMENT, A RESILIENT MEMBER OPPOSED TO MOVEMENT OF SAID FIRST CONTROL MEMBER, THE STIFFNESS OF SAID RESILIENT MEMBER BEING LOWER THAN A STIFFNESS SUFFICIENT TO PRODUCE COMPENSATION OF SAID SPRING OF THE ROLLING MILL, WHEREBY AN OVERCOMPENSATION OF THE MILL SPRING IS OBTAINED, AND ACTUATING MEANS RESPONSIVE TO THE RELATIVE POSITION OF SAID CONTROL MEMBERS FOR ACTUATING MOVEMENT OF SAID VALVE, WHEREBY STRIPS OF A CONSIDERABLE LENGTH MAY BE GUIDED BETWEEN THE ROLLS AND BE URGED INTO A STABLE AXIAL POSITION WITH REFERENCE TO THE ROLLS.