Patent 7380923 was granted and assigned to Olympus Group on June, 2008 by the United States Patent and Trademark Office.
An overflow liquid pipe is disposed in such a manner as to pass a liquid which has overflowed from a first container flowing to a second container. The overflow liquid pipe is provided with a pressurizing pipe. A liquid removing unit pressurizes the interior of the overflow liquid pipe through the pressurizing pipe to remove liquid from the overflow liquid pipe.