Air tool improvement

Claim 1

AN AIR TOOL COMPRISING A TOOL BODY, PRESSURE FLUID CIRCULATION MEANS FOR ADMITTING PRESSURE FLUID INTO THE BODY AT A CONTROLLABLE RATE, A ROTATABLY SPINDLE DISPOSED WITHIN SAID BODY ADAPTED FOR HAVING ATTACHED THERETO A WORK PERFORMING ELEMENT, AND A SELF-HOUSED MOTOR UNIT CARRIED WITHIN THE CONFINES OF THE BODY AND OPERATIVELY CONNECTED TO THE SPINDLE, SAID MOTOR UNIT COMPRISING A HOUSING, CONDUIT MEANS DISPOSED IN THE HOUSING IN COMMUNICATING WITH THE PRESSURE FLUID CIRCULATION MEANS TO ADMIT PRESSURE FLUID INTO THE HOUSING, A CYLINDRICL SLEEVE INSERT REMOVABLY DISPOSED WITHIN THE CONFINES OF THE HOUSING OF THE MOTOR UNIT, SAID SLEEVE INSERT HAVING A PLURALITY OF SPACED APART PRESSURE FLUID INLET PORTS IN COMMUNICATION WITH THE CONDUIT MEANS, SAID HOUSING AND SAID SLEEVE INSERT BEING PROVIDED WITH EXHAUST PORTS FOR EXHAUSTING PRESSURE FLUID THEREFROM, A ROTOR ECCENTRICALLY MOUNTED WITHIN THE SLEEVE INSERT FOR ROTATION RELATIVE THERETO, BEARING MEANS DISPOSED ADJACENT EACH END PORTION OF THE CYLINDER SLEEVE INSERT FOR ENABLING THE ROTOR TO BE ROTATED RELATIVE THERETO. SAID ROTOR HAVING A PLURALITY OF VANE MEMBERS CARRIED THEREBY FOR GENERALLY RADIALLY EXTENSIBLE MOVEMENT RELATIVE THERETO WITH THE VANE MEMBERS ENGAGING THE SLEEVE INSERT TO IMPINGE CIRCULATING PRESSURE FLUID AGAINST THE VANE MEMBERS AND IMPART ROTATION TO THE ROTOR, SUBSTANTIALLY FLAT DISC-LIKE WEAR PLATES REMOVABLY DISPOSED WITHIN THE CONFINES OF THE HOUSING IN ENGAGEMENT WITH THE CYLINDRICAL SLEEVE INSERT AND THE VANE MEMBERS OF THE ROTOR, AND SPACER MEANS FOR PREVENTING THE WATER PLATES FROM HAVING ANY ENGAGEMENT WITH THE BEARING MEANS.