Quick change tool holder

Claim 1

A quick change tool holder for a machine or the like having two basic assemblies which are normally attached together but are readily detached one from the other, comprising: a first component assembly having a flat surface adapted to be fastened to the machine or the like; a second component assembly having a flat surface adapted to be fastened to a tool or the like; one of the component assemblies having a central boss formed thereon with an axis extending substantially normal to the flat surface; the other component assembly having a recess formed therein with an axis extending substantially normal to the flat surface and with the recess shaped in correspondence to the boss whereby the boss is received into the recess during assembly to an attached mode of operation; the boss portion having a circumferentially extending channel formed therein; at least one elongated lock bar pivotally mounted to the other component assembly at an end portion and having an edge portion movable about the pivot mounted end portion so that the edge portion is movable into and out of the channel to lock and unlock the boss in the recess respectively; means for selectively pivoting the lock bar from a lock position to an unlock position thus permitting separation of the component assemblies including a radially extending cylinder bore extending in the boss portion normally to the boss axis and intersecting the channel; a reciprocal piston in the cylinder bore; means for selectively directing pressurized air to the radially inward portion of the reciprocal piston; means moved by the piston adjacent the edge portion of the lock bar for pivoting the edge portion radially outwardly to the unlock position.