Process for obtaining a hermetic connection for rigid tube

Abstract

In a tube fitting a nut which extends about the end of a tube allows the tube to be threadedly joined to a nipple. The end of the tube is formed in the shape of a collar which retains the nut. The face of the collar is flattened to sealingly meet with an o-ring which resides in an annular recess in the frontal surface of the nipple. The process of forming the collar in the end of the tube includes placing a nut on the tube, gripping the end of the tube with a die, and deforming the end of the tube with a tool of truncated cone-shape move in an advancing, precessing motion. The die is shaped with interior shoulders having the profile of the collar. A socket which forms the back side of the collar can be placed over the tube after the die grips the tube. After the collar formed the dies is removed.

Dependencies are inferred from the claim text.