Tube-to-hose coupling (spin-sert) and method of making same

A method of making a tube coupling, the tube coupling comprising a metal tube having an expanded radially outwardly flared integral sleeve at one end thereof, and a radially extending tube shoulder being defined a the juncture at which said sleeve is flared outwardly, said tube having a throughbore of a first inner diameter, and said expanded sleeve having a throughbore of a second inner diameter greater than said first inner diameter and concentric therewith;

• a cylindrical, hollow inert concentric with the axis of said tube and at one end being inertially welded to said tube at said radial tube shoulder;
• said insert including at its other end a cylindrical barrel portion having hose locking and sealing means;
• a flexible hose being supported on said insert barrel portion and being secured and sealed relative to said sleeve and said insert by said sleeve being crimped over said insert barrel portion to thereby extrude the hose into the sealing and locking grooves permanently holding said hose in compression;
• said insert including a radially extending annular collar at one end thereof, said collar having a tube end face abutting said radial tube shoulder and being inertially welded thereto, said insert further including a tube groove immediately adjacent said tube end face and said radial tube shoulder being extruded within and at least partially filling said groove during the inertial welding step;
• said method comprising the steps of:
• (a) locating said tube within a chuck member having a throughbore opening into a radially enlarged generally concave seat portion at one end thereof, the chuck seat portion closely conforming in radial dimension to said radially extending tube shoulder and providing a stop for the radial tube shoulder,
• (b) locating the insert on a rotatable mandrel,
• (c) rotating said mandrel under power,
• (d) inserting said insert and mandrel into said sleeve until said insert collar is brought into contact with said radial tube shoulder, and
• (e) thereafter terminating the rotational power to said mandrel and allowing the mandrel and insert to free-spin while holding the radial tube shoulder in compression between the chuck seat portion and the insert collar and thereby inertially welding the sleeve to the insert.