Patent ID: 6880832

Claim:
A chuck device for holding a tool having a tool shaft or a connecting collet, said device comprising: a chuck body including a central longitudinally extending bore therein of a predetermined circumferential shape for receiving the shaft or collet of the tool, and a pivotable portion movable between a rest position wherein the predetermined circumferential shape of the bore is maintained and there is no engagement between the pivotable portion and the shaft or collet of a tool received in the bore, and an operative position wherein a bore-facing surface of said pivotable portion extends inwardly into said bore so as to engage the shaft or collet of a tool received in said bore; and a fastener member, received in an aperture in said chuck body, for, in use, causing pivoting of said pivotable portion of said chuck body to a said operative position thereof so that the bore-facing surface of said pivotable portion engages the shaft or collet of a tool received in bore, said chuck body further including a tapered portion through which said bore extends and said chuck device further comprising a nut adapted to be affixed to said tapered portion.