Ferrule with relief to reduce galling

摘要

A recess (40) is located generally midway between the opposite ends of a ferrule (22' and this results in the inner surface of the rear ferrule being reduced to two relatively narrow contact areas (42,44). The forces are conducted from the front ferrule through the rear ferrule to a nut surface or flange (32' which tend to be directed more radially outward. The outer radial wall (50) of the rear ferrule includes a conical section that increases in radial dimension as it extends from the forward nose portion, that is received in the rear chamfer region (52) of the front ferrule, to the rear flange (26'). Preferably, the outer wall has a uniform angle or taper as it extends between the reduced dimension nose region received in the camming mouth of the front ferrule and the enlarged diameter rear flange. This provides controlled deformation of the rear ferrule so that the region is plastically deformed radially inward along surface (44) into gripping, scaled engagement with the outer wall of the tube. The rear ferrule in which the recess (40) is defined by two different angles (an obtuse triangle). The smaller first angle is defined with the inner surface which increases as it extends rearwardly from the surface toward the rear flange. The larger second angle increases as it extends forwardly from the surface (42) toward the nose region. These angles thus intersect at an axial position that is located beneath the intersection of the outer wall with the rear flange.