Spindle bearing preload assembly

Claim 1

A BEARING SUPPORT MOUNTING FOR ROTATABLE SPINDLE COMPRISING, IN COMBINATION, A SPINDLE CARTRIDGE HOUSING, A PAIR OF FRONT AND REAR ANTIFRICTION BEARINGS JOURNALLING SAID SPINDLE WITHIN SAID HOUSING, EACH OF SAID BEARINGS HAVING AN INNER RACE SECURED TO SAID SPINDLE FOR ROTATION THEREWITH AND A NONROTATABLE OUTER RACE WITH A PLURALITY OF ROLLER ELEMENTS INTERPOSED BETWEEN SAID INNER AND OUTER RACES, SAID OUTER RACE OF SAID FRONT BEARING BEING RESTRAINED AGAINST AXIAL MOVEMENT WITHIN SAID HOUSING, SAID HOUSING ALSO DEFINING AN ANNULAR CYLINDER PORTION ADJACENT SAID REAR BEARING, AN AXIALLY SLIDABLE PISTON DISPOSED IN SAID CYLINDER PORTION IN CONTACT WITH SAID OUTER RACE OF SAID REAR BEARING TO VARY THE PRELOAD ON SAID REAR BEARING IN RESPONSE TO AXIAL MOVEMENTS OF SAID PISTON, SAID PRELOAD ON SAID REAR BEARING BEING TRANSMITTED THROUGH SAID SPINDLE AND SAID INNER RACES TO SIMULTANEOUSLY VARY THE PRELOAD ON SAID FRONT BEARING, A PRESSURE CHAMBER LOCATED WITHIN SAID CYLINDER ADJACENT EACH END OF SAID PISTON WHEREBY A PRESSURE DIFFERENTIAL IN SAID CHAMBERS IS EFFECTIVE TO SELECTIVELY MOVE SAID PISTON IN OPPOSITE DIRECTIONS, AND POSITIVE STOP MEANS INTERPOSED BETWEEN SAID HOUSING AND EACH END OF SAID PISTON TO LIMIT THE AXIAL MOVEMENT OF SAID PISTON IN EACH DIRECTION SO AS TO ESTABLISH THE MINUMUM AND MAXIMUM PRELOADS ON SAID BEARINGS.