Heavy machine tool and device for depositing and placing a tool head in readiness for use

A heavy machine tool, especially boring and milling machine, which is adapted to selectively receive one of a plurality of tool heads having machining tool means mounted thereon, said machine tool including:

• a stand horizontally movable along a bed, a headstock vertically displaceably mounted on said stand, a supporting sleeve slidable in said headstock, a rotary boring spindle drive means having an axis of rotation arranged in said supporting sleeve, a pull rod operable chucking device arranged in said supporting sleeve for respectively driving and chucking a heavy tool head therein, said tool head comprising a housing adapted to be supported by said supporting sleeve and containing tool drive elements engageable with said spindle drive means, the outer peripheral surface of said housing being provided intermediate its ends with a circumferential circular groove located all around in a plane substantially perpendicular to the axis of rotation of said boring spindle, at least one device for the deposit of a tool head in readiness for use, said last mentioned device including a vertically standing holding plate means having an upper edge corresponding in contour to the said circular arc-shaped annular groove of said tool head and having a thickness corresponding to the width of said groove, said plate being adapted to receive and support said tool head by means of said groove, said device being located within the range of movement of the respective stand and tool head whereby the slide by movement with respect to said plate may deposit a tool head directly on said plate or engage a tool head while it is supported by said plate.