Quick change power tool chuck

Abstract

An improved quick change power tool chuck is provided which is principally used on a wood working router but could also be used in many other power tool applications. Key features of the quick change chuck include the unique way that it secures the cutting bit from unwanted slippage, the large mechanical advantage thereof and the speed in which a cutting bit can be removed and replaced. The chuck can be aligned and attached to the power tool in the same manner that a standard collet is aligned and attached to the router spindle or to a router or other drive shaft in a number of different ways.

1 . 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 said bore,   said chuck body being formed integrally with a main motor shaft of a motor-driven drive device, and said main motor shaft including an electrical armature affixed thereto.   
     
     
         2 . A chuck device according to  claim 1  wherein the shaft or collet of the tool has an outer circumference and wherein, in the operative position of said pivotable member, the bore-facing surface of the pivotable member engages a substantial portion of the outer circumferential surface of the shank or collet. 
     
     
         3 . A chuck device according to  claim 1  wherein said pivoting portion is formed integrally with the chuck body. 
     
     
         4 . A chuck device according to  claim 3  wherein said chuck body includes an annular portion including first and second orthogonal slots therein which divide said annular portion into said pivotable portion and a fixed portion. 
     
     
         5 . A chuck device according to  claim 4  wherein said first slot extends inwardly from an end surface of the annular portion parallel to the longitudinal axis of the bore. 
     
     
         6 . A chuck device according to  claim 4  wherein said annular portion includes a circumferential surface defining the longitudinal thickness of the annular portion and first and second opposed end surfaces spaced apart by said thickness, wherein said first slot extends into said first end surface of said annular portion for a distance greater than one half of said thickness and terminates short of said second end surface, and wherein said second slot extends into said annular portion orthogonally to said first slot from said circumferential surface so as to terminate in said annular portion along a line a portion of which is substantially coextensive with said first slot. 
     
     
         7 . A chuck device according to  claim 1  wherein said chuck body comprises a main body portion and said pivotable portion comprises a pivot arm formed separately from said main portion and pivotably mounted thereon. 
     
     
         8 . A chuck device according to  claim 7  wherein said arm is of a substantially U-shaped configuration having a first, pivoted end and a second, free end and defining said bore-facing surface between said first and second ends. 
     
     
         9 . A chuck device according to  claim 8  wherein said fastener element, in use, engages the free end of said arm to clamp said bore-facing surface of said arm against the shank or collet of a tool received in said bore. 
     
     
         10 . A chuck device according to  claim 9  wherein said free end of said arm includes a threaded opening therein, and wherein said fastener element comprises a cap screw including a threaded portion adapted to be screwed into said threaded opening. 
     
     
         11 . A chuck device, adapted to be driven by a drive shaft, 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 said bore,   said chuck body further including a proximal coupling portion for coupling the chuck device to the drive shaft, and said chuck device further comprising a coupling member adapted to be coupled to said proximal coupling portion.   
     
     
         12 . A chuck device according to  claim 11  wherein the shaft or collet of the tool has an outer circumference and wherein, in the operative position of said pivotable member, the bore-facing surface of the pivotable member engages a substantial portion of the outer circumferential surface of the shank or collet. 
     
     
         13 . A chuck device according to  claim 11  wherein said pivoting portion is formed integrally with the chuck body. 
     
     
         14 . A chuck device according to  claim 11  wherein said coupling member comprises a nut including a cylindrical side wall having internal screw threading and including a circumferential slot, wherein said coupling portion of said chuck body includes a circumferential slot in an outer surface thereof, and wherein said chuck device further includes at least one locking ring adapted to be received in the slots in said nut and said coupling portion of said chuck body so as to provide locking of said nut on said chuck body. 
     
     
         15 . A chuck device according to  claim 11  wherein said coupling member includes a tapered portion for engaging a reciprocally shaped tapered portion of said proximal coupling portion of said chuck body. 
     
     
         16 . A chuck device, adapted to be driven by a drive shaft, 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, located at the distal end thereof and 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 said bore,   said chuck body including an integral coupling portion located at the proximal end thereof and shaped so as to mate with a reciprocally shaped portion of the drive shaft.   
     
     
         17 . A chuck device according to  claim 16  wherein said coupling portion includes an integral male shank. 
     
     
         18 . A chuck device according to  claim 16  wherein said coupling portion includes a shaped recess adapted to receive a reciprocally shaped male portion of the drive shaft. 
     
     
         19 . A chuck device as claimed in  claim 18  wherein said bore in said chuck body includes a counterbore at the proximal end thereof for receiving an attachment bolt for attaching the chuck body to the male portion of the drive shaft. 
     
     
         20 . A chuck device as claimed in  claim 18  wherein said recess is shaped so as to prevent relative axial rotation between the chuck body and the drive shaft.