Roller grinding mill and control therefor

Claim 1

THE COMBINATION IN A MATERIAL PULVERIZING MILL OF: A FIXED GRINDING MEMBER; A PLURALITY OF GRINDING ROLLS; ELONGATED HANGER MEANS, EACH INCLUDING AN OUTER SLEEVE HAVING AN UPPER OPEN END AND CONNECTED AT A LOWER END TO A GRINDING ROLL, AN INNER SUPPORTING SHAFT FOR EACH OUTER SLEEVE HAVING ONE END ENGAGED WITHIN SAID OUTER SLEEVE AND AN OPPOSITE END EXTENDING ABOVE THE UPPER OPEN END OF SAID OUTER SLEEVE, A PIVOT MEMBER ON SAID OPPOSITE END OF EACH SAID SUPPORTING SHAFT TO CLOSE THE UPPER OPEN END OF SAID OUTER SLEEVE, AND AN EXTENSION ELEMENT PROJECTING ABOVE EACH PIVOT MEMBER; HEAD MEANS TO SUPPORT EACH HANGER MEANS INCLUDING PIVOTS ENGAGED WITH EACH PIVOT MEMBER IN POSITION TO NORMALLY LOCATE SAID GRINDING ROLLS PENDENTLY ADJACENT SAID FIXED GRINDING MEMBER; DRIVE SHAFT MEANS CONNECTED TO SAID HEAD MEANS TO ROTATE THE SAME ABOUT A FIXED AXIS AND CAUSE SAID HANGER MEANS TO SWING IN A DIRECTION RADIALLY OF SAID FIXED AXIS OF ROTATION AND MOVE SAID GRINDING ROLLS INTO SAID GRINDING MEMBER; INDIVIDUAL PRESSURE FLUID RESPONSIVE POSITION CONTROL MEANS BETWEEN SAID DRIVE SHAFT AND EACH EXTENSION ELEMENT TO SUBSTANTIALLY FIX THE RADIAL DISTANCE FROM SAID FIXED AXIS OF ROTATION TO EACH OF SAID EXTENSION ELEMENTS AND, HENCE, THE POSITION OF SAID GRINDING ROLLS RELATIVE TO SAID FIXED GRINDING MEMBER; AND A PRESSURE FLUID SYSTEM INCLUDING HIGH PRESSURE SUPPLY AND LOW PRESURE SUPPLY MEANS CONNECTED TO OPPOSITE SIDES OF SAID CONTROL MEANS, REGULATOR MEANS IN SAID HIGH PRESSURE SUPPLY AND FLOW RESTRICTION MEANS IN SAID LOW PRESSURE SUPPLY, SAID REGULATOR MEANS BEING SELECTIVELY SETTABLE FOR GIVEN RADIAL DISTANCE, AND SAID FLOW RESTRICTION MEANS DAMPING ROLL ACTION TO CHANGE THE RADIAL DISTANCE.