Patent ID: 7695027

Claim:
A conduit fitting, comprising: a female threaded body having an interior bore for receiving a conduit along a central axis, the interior bore having first and second camming surfaces; a generally annular first ferrule having a first end portion and a second end portion, the first end portion having a tapered outer surface for engaging the first camming surface to form a primary seal against fluid pressure; a generally annular second ferrule having a first end portion engaging the second end portion of the first ferrule and a second end portion defining a driven surface; the first end portion including a sharp edge for biting into the conduit; and a male threaded nut threadably joined with the female threaded body, the nut including a central through bore for receiving the conduit, a front end having a socket defined by an axially extending cartridge; the socket having a first portion adapted to receive at least a portion of the first ferrule and a second portion adapted to receive the second ferrule; the second portion defining a drive surface adapted to engage the driven surface of the second ferrule at a location that is radially spaced from the conduit; the cartridge having a tapered surface for engaging the second camming surface, wherein the engagement between the tapered surface and the second camming surface causes the amount of torque required to continue pulling-up the fitting to sharply increase, wherein said engagement between the tapered surface and the second camming surface comprises direct contact between the tapered surface and the second camming surface.