Method and apparatus for maintaining substantially constant strip gauge in a tandem mill

Claim 1

IN A STRIP ROLLING MILL COMPRISING AT LEAST TWO MILL STANDS HAVING SCREW-DOWN MECHANISM AND MILL DRIVE MOTORS, THROUGH WHICH THE STRIP PASSES IN BEING ROLLED, A GAUGE DISPOSED TO SENSE THE THICKNESS OF THE STRIP ISSUING FROM ONE OF THE MILL STANDS AND TO PRODUCE A QUALITATIVE ELECTRICAL SIGNAL UPON DEVIATION OF THE STRIP THICKNESS FROM A PREDETERMINED GAUGE, AT LEAST ONE OF SAID MILL STANDS BEING A CONTROL STAND, MEANS FOR CAUSING SAID QUALITATIVE SIGNAL TO INITIATE OPERATION OF SAID SCREW-DOWN MECHANISM OF SAID CONTROL STAND IN THE APPROPRIATE DIRECTION TO CORRECT SAID DEVIATION, A SPEED CONTROL FOR THE MILL DRIVE MOTOR OF SAID CONTROL STAND, AN OPERATIVE CONNECTION BETWEEN SAID SCREW-DOWN MECHANISM AND SAID SPEED CONTROL, WHEREBY SAID SPEED CONTROL IS ACTUATED IN THE APPROPRIATE DIRECTION CONCURRENTLY WITH SAID SCREW-DOWN MECHANISM TO COMPENSATE FOR CHANGE IN TENSION ON THE STRIP BETWEEN SAID MILL STANDS WHICH WOULD OTHERWISE BE PRODUCED BY SAID SCREW-DOWN OPERATION, MEANS FOR MEASURING THE AMOUNT OF MOVEMENT OF SAID SCREW-DOWN