Patent ID: 8172927

Claim:
An apparatus for filtering sectioning wastes of a microtome that are present in an air stream, having an aspiration device with which sectioning waste can be aspirated from a blade region of the microtome with an air stream, the aspiration device comprising: a main filter in which the sectioning wastes can be filtered from the air; and a prefilter for prefiltering the sectioning wastes, wherein the prefilter is arranged between the blade region and the main filter; the prefilter comprises a valve having two valve positions, wherein with the valve assuming a first valve position, the air stream flowing through the prefilter being directed into a flow direction provided for the filtering position; and with the valve in a second valve position that differs from the first valve position, the air stream flowing through the prefilter being directed into a flow direction provided for the emptying position; wherein the prefilter comprises a conical filter insert or a conical filter region that has at least one of a mesh-shaped, lattice-shaped, and hole-shaped structure that is configured substantially conically and tapers in the direction of the air stream; the valve is arranged at the downstream end of the conical filter insert or conical filter region of the prefilter; an opening is provided that can be closed off by the valve, wherein the valve closes the opening when assuming the first valve position so that the air stream is directed through the hole-shaped structure of the filter insert or filter region; and the valve opens the opening when assuming the second valve position so that almost the entire air stream is directed through the opening.