Air driven turbines for dental handpieces and the like

Claim 1

A HIGH SPEED AIR DRIVEN ASSEMBLY COMPRISING A CYLINDRICAL SHELL HAVING A CYLINDRICAL BORE, OPEN AT BOTH ENDS, AND HAVING A LATERAL INLET PORT AND A LATERAL OUTLET PORT SPACED AXIALLY FROM EACH OTHER, A CYLINDRICAL STATOR HAVING AN AXIAL THROUGH BORE AND FITTING IN SAID SHELL BORE, AND COMPRISING A PAIR OF CYLINDRICAL ANNULAR FLANGES SEPARATED BY A PERIPHERAL GROOVE COMMUNICATING WITH SAID INLET PORT AND FORMING AN AIR MANIFOLD, ONE OF SAID FLANGES ENGAGING ONE END OF SAID SHELL AND CLOSING OFF AIR FROM ONE END OF SAID SHELL, AND THE OTHER OF SAID FLANGES HAVING A PLURALITY OF DIAGONAL OPEN SLOTS CUT IN ITS PERIPHERY AND FORMING AIR NOZZLES RECEIVING AIR FROM SAID AIR MANIFOLD, SAID SLOTS BEING CLOSED AT THE PERIPHERY OF THE STATOR BY SAID SHELL, A BALL BEARING ASSEMBLY AT EACH END OF SAID TURBINE ASSEMBLY, EACH BALL BEARING ASSEMBLY COMPRISING AN OUTER RACE, ONE OUTER RACE ENGAGING THE STATOR AND THE OTHER OUTER RACE ENGAGING ONE END OF THE SHELL, A PLURALITY OF SPACED BALLS LOCATED IN AN INNER CONTINUOUS GROOVE IN EACH OUTER RACE, AND AN INNER RACE AT EACH END OF THE ASSEMBLY, AND EACH INNER RACE HAVING AN OUTER CONTINUOUS GROOVE ENGAGING THE SPACED BALLS OF ITS BALL BEARING ASSEMBLY, A CYLINDRICAL TURBINE SHAFT HAVING AN ANNULAR SHOULDER AT ONE END AND A THREADED PORTION AT ITS OTHER END, A TURBINE ROTOR HAVING A THROUGH BORE FITTING ON SAID SHAFT, AND COMPRISING A CYLINDRICAL BODY WITH A TUBULAR SPACER SLEEVE AT EACH END, SAID SPACER SLEEVES EACH ENGAGING THE END OF ONE OF SAID INNER RACES AND A THREADED MEMBER CARRIED BY SAID THREADED PORTION OF SAID SHAFT AND CLAMPING SAID INNER RACES AGAINST THE TUBULAR SPACERS AND AGAINST THE ANNULAR SHOULDER AT THE END OF THE SHAFT, FORMING A UNITARY ASSEMBLY, SAID ROTOR HAVING A CLEARANCE BETWEEN ITS SPACER SLEEVE AND THE STATOR BORE AND BETWEEN ONE END OF THE STATOR CYLINDRICAL BODY AND THE ADJACENT END OF THE CYLINDRICAL ROTOR BODY, PERMITTING LEAKAGE OF AIR THROUGH SAID CLEARANCES AND THROUGH THE SPACES BETWEEN THE BALLS OF THE BALL BEARING AT THAT END OF THE SHELL, SAID ROTOR HAVING A PLURALITY OF CURVED CONCENTRIC WALLED SLOTS IN ITS PERIPHERY, FORMING CURVED VANES LOCATED IN CLOSE PROXIMITY TO BUT HAVING A CLEARANCE WITH RESPECT TO THE BORE IN SAID SHELL, SAID AIR NOZZLES DIRECTING AIR PERIPHERALLY AND AXIALLY INTO SAID ROTOR SLOTS IN THE DIRECTION OF ROTATION OF THE ROTOR, WHICH DISCHARGES THE AIR DOWNWARDLY FROM THE ROTOR INTO AN EXHAUST CHAMBER COMMUNICATING WITH SAID OUTLET PORT AND WITH THE SPACES BETWEEN THE BALLS OF THE ADJACENT BALL BEARING ASSEMBLY, FOR COOLING THE BALL BEARINGS AND PRODUCING AIR FLOW OUT OF THE END OF THE ASSEMBLY TO EXCLUDE DIRT BY OUTWARD FLOW.