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AssigneeEidgenossische Technische Hochschule Zurich Nichtmetallische Werkstoffe
InventorsFrank Filser, Ludwig Gauckler, Peter Kocher, Heinz Luethy, Peter Schaerer, Heiner Hoerhold, Peter Kreuder, Stefan Fecher
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A holding device comprises a cylindrical or prismatic, porous ceramic blank and elements for clamping in a machine tool for processing the blank by removing material, in order to produce a ceramic workpiece. A narrow frame is fixed by an adhesive connection over at least part of the periphery of the blank, which is held without stresses, in the area of a plane encompassing the longitudinal middle axis (A) of the blank. The frame only covers a small part of the surface of the blank and can be detached and held in a stable holder with a clamping adapter, in such a way that it cannot slide. The entire combination is fixed in the machine tool in such a way as to be resistant to twisting and sliding. The ceramic workpiece emerges continuously form the ceramic blank without predetermination of the advance direction, until holding segments which can then only be freely selected according to number and location have been formed. The holding segments end on the residual material of the blank in the area of the frame or on the frame itself. The holding device is used especially as a workpiece for producing fully ceramic dental prostheses, particularly crowns or bridges.
In combination, a porous ceramic blank having a longitudinal axis A and holding means, said holding means comprises (1) a frame which is adhesively bonded to at least a portion of a surface of the blank wherein the blank is held by the frame without tension in a region of a plane which includes the longitudinal axis A, (2) a holder wherein the frame is detachably secured against slipping in the holder, and (3) clamping adaptor means for securing the holding means in a machine tool for the material-removing machining of the blank.
Dependencies are inferred from the claim text.