Work-engaging and positioning device for machine tools

Claim 1

A GRINDING MACHINE HAVING AN ABRASIVE BELT ADAPTED UPON MOVEMENT THEREOF TO PERFORM A GRINDING OPERATION ON A WORKPIECE, COMPRISING A WORK-SUPPORTING MEMBER; A WORKPIECE-HOLDING FIXTURE MOUNTED ON SAID WORK-SUPPORTING MEMBER ADAPTED TO OPERATIVELY POSITION A WORKPIECE IN RELATION TO SAID GRINDING BELT, SAID FIXTURE COMPRISING FIRST AND SECOND ANNULAR MEMBERS DISPOSED ABOUT A REFERENCE AXIS, A RECESS DEFINED BY ONE OF SAID MEMBERS ADAPTED TO RECEIVE A WORKPIECE INSERTABLE THEREIN, SAID ONE OF SAID MEMBERS HAVING AN ANNULAR PROJECTION OF REDUCED DIMENSION EXTENDING AXIALLY THEREFROM, THE OTHER OF SAID MEMBERS HAVING AN ANNULAR INNER-PERIPHERAL SURFACE RECEIVING SAID PROJECTION CONCENTRICALLY THEREIN, SAID OTHER OF SAID MEMBERS BEING ROTATABLE ABOUT SAID PROJECTION AND SAID AXIS WITH RESPECT TO SAID ONE OF SAID MEMBERS; A PLURALITY OF CHUCKING ELEMENTS HAVING WORK-ENGAGING SURFACES THEREON ADAPTED TO ENGAGE AND POSITION A WORKPIECE TO BE GROUND IN SAID RECESS, EACH OF SAID CHUCKING ELEMENTS BEING PIVOTED ABOUT A RESPECTIVE POINT ON ONE OF SAID MEMBERS; CHUCKING ELEMENT-ACTUATING MEANS ON THE OTHER OF SAID MEMBERS ARRANGED TO EXERT A FORCE ON SAID CHUCKING ELEMENTS UPON ROTATION OF SAID OTHER OF SAID MEMBERS, TO THEREBY ADJUST THE POSITION OF SAID WORKENGAGING SURFACES WITH RESPECT TO SAID AXIS; AND ADJUSTING MEANS INTERCONNECTING SAID MEMBERS FOR ROTATIVELY PREDETERMINING THE POSITION OF SAID OTHER OF SAID MEMBERS ABOUT SAID PROJECTION.