Patent ID: 6109665
Filing Date: 2000-08-29
Classification: F16L,F24F

Abstract:
A butt joint between two sheet metal air duct sections with a duct wall having a circular or oval cross section, comprising:a connection flange of sheet metal on at least one end of each air duct section for forming the butt point with an abutting air duct section, each connection flange being constructed integrally, in one piece, with an adjoining duct wall, each connection flange having at least one annular edge projecting outward from the adjoining duct wall, said at least one annular edge having a radially inner end and a radially outer end;a clamping leg projecting conically backward from the radially outer end of the at least one annular edge of each connection flange and directed towards the duct wall integrally adjoining said connecting flange;a clamping ring having conical side legs mountable on an adjacent pair of connection flanges of abutting air duct sections wherein said radially inner ends of said connection flanges come in direct contact with one another, said conical side legs disposed on corresponding clamping legs of the adjacent pair of connection flanges and holding said adjacent pair of connection flanges together;characterized in that the at least one annular edge that forms part of the connection flange encloses, together with the adjoining duct wall, in a non-load-bearing state, an angle of 80.degree. to less than 90.degree., and said at least one annular edge transitions into the duct wall at a sharp angle at its radially inner end.