Abstract: An apparatus for layerwise production of an object using laser sintering by solidifying a material which is solidifiable by electromagnetic radiation comprises a device (5) for producing an electromagnetic beam (6) and a focusing device (8) for focusing the beam (6) onto the material within a working plane (7), whereby the focusing device (8) comprises a lens (9) and a mount (10) holding the lens (9), a ring nozzle (12) arranged adjacent to the image-side surface (11) of the lens (9) facing the working plane (7), the ring nozzle having its outlet oriented relative to the image-side surface (11) so that a discharged stream strokes tangentially along the image-side surface (11) towards the center, the inlet of the ring nozzle being selectively connected with a source of pressurized gas.

Abstract: In an apparatus for producing a three-dimensional object by laser sintering the object is produced by successive solidification of layers of a powder material at points corresponding to a cross-section of said object using radiation for solidifying said powder material. The apparatus includes a support having a substantially plane upper side for supporting the object, a material applying device for applying a layer of the material onto the upper side or onto another layer formed on the upper side, and a solidification device for solidifying a layer of the material by irradiation. The material applying device has a coating device and a drive for displacing the coating device in a direction parallel to the upper side of the support.