Abstract: A hand held reciprocating mechanism for driving an abrasive tool for finishing dies and the like is disclosed. The reciprocating mechanism of the present invention includes a housing which supports a tool holding assembly, and a drive mechanism including a crank pin which reciprocates a connecting rod which is operatively coupled to the tool holding assembly. The tool holding assembly is supported for reciprocation by a support bushing which is supported by the housing. An internal retaining ring is employed to attach a tool support housing to the tool support bushing and allow rotation of the tool support housing relative to the tool support bushing. The retaining ring allows the use of an enlarged outer end for the tool support housing with a slot formed therein to slidingly support a pair of opposed flats formed on the tool holding assembly. This permits the tool holding assembly to support heavy transverse loads without excessive wear between the tool holding assembly and the tool support housing.

Abstract: A quick change tool holder is disclosed which allows tools to be changed while a collet holding the tools is rotating. The quick change tool holder comprises a stationary housing, a quill rotatably supported within the housing, a collet rotatingly engaged by the quill, the collet adapted to releasingly engage a tool. A rotatable sleeve threadingly engages the housing, and rotation of the sleeve in a first direction releases a tool held in the collet for removal of the tool while the collet is rotating. Rotation of the sleeve in a second direction engages the shank of a tool that has been placed within the collet for rotation therewith. The removal or insertion of a tool can be made while the collet is rotating.