Patent ID: 7600792
Filing Date: 2009-10-13
Classification: B60T,F16L

Abstract:
1. A flared end structure of a metal tube to be pressed against a seat formed in a member by tightening a coupling nut to the member, having a joining end part to be pressed against the seat of the member, and a curved part continuous with the joining end part; wherein the curved part has a curved outer surface with respect to the axis of the tube and a concave inner surface having a bottom edge, and the curved outer surface merges into a flat surface of a neck part, on which the coupling nut exerts pressure, the flat surface of the neck part being connected to an outer surface of the metal tube by a curved connecting surface having a center of curvature at a position radially outside the metal tube, and a distance including a tolerance between the flat surface of the neck part and the end of the joining end part of the metal tube meeting an inequality: D D D r: Radius of curvature of the curved connecting surface α: Cone angle of a cone containing the joining end part t: Wall thickness of the tube.