An adjustable duct assembly for the collection of fumes, dust and the like comprises two duct sections pivotally connected end to end and to a base by an external duct support system. The duct sections are retained in a selected position without the need for any friction fittings by a combination of...http://www.google.de/patents/US6524180?utm_source=gb-gplus-sharePatent US6524180 - Adjustable duct assembly for fume and dust removal
