Abstract: A clamping apparatus for attaching work pieces to be machined to the work table of a machine tool in a precisely defined position comprises at least one clamping rail to be attached to the work table of the machine, as well as at least one work piece holder. The clamping rail is provided with an elongate protruding portion, the front face thereof constituting a stop surface and which defines a recess between itself and the work table of the machine tool. The elongate protruding portion may be provided with threaded bores for receiving clamping screws. Each work piece holder includes a clamping portion which can be inserted into the recess and clamped therein by means of the clamping screws. The clamping rail includes a flat bottom surface resting on the surface of the work table of the machine tool and running perpendicular to the aforementioned front face of the elongate protruding portion.

Abstract: The clamping apparatus comprises a clamping holder and a pallet releasably attachable thereto. The clamping holder is provided with first centering elements, which cooperate with second centering elements correspondingly located on the pallet in such a way that the pallet is attached to the clamping holder in a positionally well defined manner. The clamping holder, moreover, comprises two clamping elements for attaching the pallet to the clamping holder. Each clamping element has an oblique thrust surface; upon clamping the pallet to the clamping holder, the pallet is shifted in the X-Y-plane to rest on the first centering elements of the clamping holder. Simultaneously, the pallet is pulled in Z-direction towards the clamping holder and fixed thereto.

Abstract: The clamping apparatus provides for a positionally accurate clamping of a work piece having at least one shaft with a polygonal cross section. To this end, the clamping apparatus is provided with a clamping body member, having a clamping chamber with polygonal cross section adapted to receive the shaft of the work piece. The clamping body member is provided with clamping means to clampingly fix the shaft to the clamping body member, and with reference surfaces for determining the position of the work piece in X- and Y-directions. The reference surfaces are constituted by stop pin members inserted into bores provided in the clamping body member, whereby the stop pin members are made of a material that is harder than the material of the clamping body member. The stop pin members are of cylindrical shape, whereby the bores receiving the stop pin members open into the clamping chambers such that a small portion of each stop pin member protrudes into the interior of the clamping chamber.